HIV-associated neurocognitive disorders (HAND) are one of the HIV-associated comorbidities affecting 20–50% of the people with HIV (PWH) infection. We found that the soluble insulin receptor (sIR) levels in plasma and cerebrospinal fluid (CSF) were significantly higher in HIV-infected women. The mechanism of sIR release into the plasma remains unknown, but the detection of the sIR in exosomes may uncover novel mechanisms of sIR secretion from HIV-infected cells and its contribution to HIV disease progression and HAND development. Quantification of sIR in urine may represent a less invasive and more accessible diagnostic tool. Our objective was to quantify sIR levels in plasma, plasma-derived exosomes, and urine, and evaluate their association with HAND and renal function.We measured full-length sIR in the plasma and urine of 38 controls and 76 HIV-infected women by ELISA, and sIR, HIV-1 Tat, and reactive oxygen species (ROS) in exosomes by flow cytometry.p = 0.762). In HIV-infected women, higher plasma sIR correlated with lower urine sIR that could suggest sIR retention in blood or decreased renal filtration.Plasma and exosomes with sIR were significantly higher in HIV-infected women when compared with controls and HAND. Exosomal sIR positively correlated with exosomal ROS and exosomal HIV-1 Tat in HIV-infected women. Exosomal ROS was significantly higher in HIV-infected women with more symptomatic cognitive impairment. Plasma-derived exosomes exhibited significantly higher levels of astrocyte (GFAP) and neuronal (L1CAM) markers in HIV-infected women, confirming the presence of circulating CNS-derived exosomes in the blood of HIV-infected women. Urine sIR positively correlated with eGFR in controls, but not in HIV-infected women, regardless there was no significant difference in renal function as determined by the estimated glomerular filtration rate (eGFR, Higher plasma sIR levels and their correlation with ROS in plasma-derived exosomes with HAND suggest a combined role of metabolic disturbances, oxidative stress, exosome release, and cognitive decline. Communication between CNS and periphery is compromised in PWH, thus plasma-derived exosomes may shed light on disrupted cellular mechanisms in the brain of PWH. High plasma and low urine sIR levels could suggest sIR retention in blood or decreased renal filtration. The introduction of combined antiretroviral therapy (cART) to HIV treatment has improved the life quality and expectancy of people with HIV infection (PWH), transforming the disease into a chronic condition. However, this increased life expectancy combined with the long-term infection and cART, has increased the risk of comorbidities such as cardiovascular diseases, chronic inflammation, changes in body composition and metabolic activity, and insulin resistance –4. In thPreviously, we demonstrated that HIV-infected women with cognitive impairment have higher levels of soluble insulin receptor (sIR) in plasma and cerebrospinal fluid (CSF), when compared to HIV-negative women, as well as lower levels of insulin receptor substrate 1 (IRS-1) tyrosine phosphorylation in plasma –15. MetaAlthough plasma, CSF, and exosomal sIR could serve as a biomarker for the presence and severity of HAND, there is a need for more accessible and less invasive diagnosis methods. Measuring full-length sIR in urine can reduce not only the risk of infection and pain in a blood collection method but also the sampling cost. For these reasons, in this study, we also investigated if sIR was present in the urine of HIV-infected women and their association with HAND and renal function. The quantification of sIR subunits in the urine has been previously explored as a good marker for evaluating diabetes risk , 29. It N = 86) HIV-infected women without a history of diabetes and thirty-five (N = 35) HIV-negative controls were evaluated, as previously described (n = 44), asymptomatic impairment , and symptomatic impairment . The estimated glomerular filtration rate (eGFR) was calculated from serum creatinine (mg/dL) using a validated Chronic Kidney Disease Epidemiology Collaboration equation validated in 2009 by Levey et al. in a population of Caucasian and African–American study participants  Institutional Review Board #1330315), and all the participants signed written informed consent. This is a unique cohort of Hispanic HIV-infected women characterized by viral and immune profiles, neurological exams, and neuropsychological tests. A total of eighty-six . No proteinuria or albuminuria was observed among the participants. Most HIV-infected women were using antiretroviral therapy (ART)  with protease inhibitors . There was no significant difference between groups of HAND severity in either use of ART, protease inhibitor, or CNS penetration effect .p < 0.05] and with toxicology infected results  compared to controls . Differences were not seen with urine sIR between these three groups, however, similar elevated levels of ROS per exosome were observed (p < 0.05).When we compared plasma sIR levels across groups defined by HIV-infected and infected toxicology status, the levels were significantly increased in HIV-infected women without infected toxicology results [median (IQR): 10,556 , Given that no controls had infected the toxicology results, we did not include an interaction term between toxicology and HAND status. While our sample size was not sufficient to perform a non-parametric regression of plasma sIR as a function of HAND status and toxicology, we did use a log transformation of plasma sIR and conduct a linear regression with these main effects and an interaction term. Controlling for the influence of infected toxicology results, log plasma sIR was significantly elevated in HIV-infected women with symptomatic cognitive impairment.PWH using cART suffer metabolic alterations that could contribute to the development of HAND , 2, 36. via exosome release  University of Puerto Rico, Medical Sciences Campus. The patients/participants provided their written informed consent to participate in this study.VW and YG were responsible for the conception and design of the study. VW, YC-R, YG, MM, RR, BD, RR-B, and ER contributed to the data acquisition. VW, YC-R, RS, and YG were involved in the analysis and interpretation of data. VW, YC-R, and YG drafted the first version of the article. All authors critically revised the manuscript for important intellectual content. All authors gave final approval of the version to be submitted.This work was supported by R01NS099036, R21MH095524, UPR-MSC Center for Collaborative Research in Health Disparities U54MD007600, NYU COMRADE Program R25NS094093, K22NS118975, and The Hispanic Alliance for Clinical and Translational Research (Alliance) U54GM133807.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Most men who have sex with men (MSM), especially those with HIV infection, do not disclose their same-sex behaviors in China due to Chinese family values and fear of stigmatization, rejection, or prejudice. However, disclosure of same-sex behaviors to healthcare providers (HCPs) can be beneficial for reducing viral transmission and promoting their physical and mental health. In this study, by combining phylogenetic analysis with traditional epidemiological approaches, we tried to identify the MSM who do not disclose to HCPs in transmission networks and explored the factors related to the non-disclosed behaviors.pol sequences obtained from the drug-resistant surveillance program, which was collected as part of routine clinical care since 2012. Sequences were linked to the demographic data collected in the Chinese HIV/AIDS Comprehensive Response Information Management System (CRIMS). First, male patients in whom genetic sequences were within the molecular transmission clusters involving self-reported MSM were identified as potential MSM (pMSM). Then, a cross-sectional survey was conducted to supplement behavioral information and attitudes toward MSM.Phylogenetic analysis was conducted using HIV Our sample consisted of 190 pMSM patients. In total, 43.16% of the patients were likely to conceal same-sex behaviors during the first-self-report, and 14.73% of patients might continue to conceal a history of same-sex behaviors even after receiving medical care. The pMSM who concealed their same-sex behaviors were reluctant to accept medical services such as Voluntary Counseling and Testing (VCT) and had a lower likelihood of condom use. In addition, the related factors for non-disclosed behavior were associated with current address, income before diagnosis, and attitudes toward MSM.Non-disclosure of same-sex behaviors to HCPs may be a major obstacle for certain medical services for MSM who exhibit risky sexual behaviors. The pMSM from developing areas, with high monthly income, and with neutral or un-supportive attitudes toward MSM may represent non-disclosure of their same-sex behaviors. Thus, policies facilitating MSM to disclose their same-sex behaviors are recommended, such as legislations protecting homosexual rights on employment, education, marriage, and so on. In most countries, the prevalence of HIV among men who have sex with men (MSM) is higher than in the general population and continues to rise . Since tIn traditional Chinese culture, homosexuality is large disobedience of family values . MSM in Phylogenetic analysis has been confirmed as an effective measure to identify and dissect HIV transmission clusters  and to iA phylogenetic analysis was performed that uses special sequences of HIV pol amplified from patient samples obtained from the drug-resistant surveillance program in Guangyuan city, which was collected as part of routine clinical care since 2012. A local HIV-1 genetic transmission network had been constructed, and we selected male patients whose genetic sequences were within the molecular transmission clusters involving self-reported MSM in the Chinese HIV/AIDS Comprehensive Response Information Management System (CRIMS). These samples of male patients older than 18 years with long-term medical care for more than 1 year in those clusters were defined as potential MSM (pMSM). A cross-sectional survey targeting “pMSM” was conducted from November to December 2021 in Guangyuan city of Sichuan province, China. The survey was conducted by HCPs engaged in the follow-ups of people living with HIV/AIDS through face-to-face or telephone interviews. Participants were verbally informed of the purposes and procedures of the study, the sensitive nature of the questions, the level of confidentiality, the compensation, and their rights to refuse or stop the interview. Next, study participants were asked to verbally express their understanding and consent of the study. This study was reviewed and approved by the ethics committee of the Sichuan Center for Disease Prevention and Control.Sequences were generated from the HIV-1 pol. The Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was used to amplify the full-length protease gene in the pol region and the first 300 codons of the reverse transcriptase gene . Local HWe extracted part of the data from CRIMS , includiFor the participants who reported same-sex behaviors in the survey, the same-sex behavior model and same-sex dating model were further investigated, including the first same-sex sexual age, the average monthly numbers of same-sex partners before diagnosis, same-sex partner type before diagnosis, and condom use with the same-sex partner in the last month before diagnosis.Self-reported MSM, who reported themselves as MSM in CRIMS, and also disclosed their same-sex behaviors in the survey. (2) Medical care-reported MSM, refers to those pMSM who first reported themselves as heterosexual in CRIMS, while under receiving long-term medical care, they finally disclosed their same-sex behaviors in the survey. (3) Self-reported heterosexual man, the others who self-reported as heterosexual in both CRIMS and the survey.We classified pMSM into three categories based on self-reported sexual behavior in CRIMS and/or in the survey. (1) p < 0.05 at this step were considered eligible for the multivariate analysis. The significance level was fixed at α = 0.05.All data analyses were completed using SPSS 23. For the descriptive analysis, we compared basic demographic characteristics and behavioral information obtained from the survey of the participants who had disclosed their same-sex behaviors to those who had not, and Chi-square test was performed to examine the relationships among variables of interest. Univariate and multivariate logistic regressions were used to evaluate factors associated with same-sex behaviors disclosure among the participants. A total of 15 variables were tested. Each of these variables was first tested using univariate modeling and these variables with a A total of 283 male patients were identified as pMSM, whose genetic sequences were within the self-reported MSM clusters. However, 93 pMSM were transferred to treatment elsewhere and could not be contacted, or refused to be investigated. Thus, our sample consisted of 190 pMSM patients. All the sequences contained in networks of pMSM were analyzed by constructing a local MSM HIV-1 genetic transmission network. As shown in n = 104) of pMSM kept neutral attitude and 13.7% (n = 26) kept un-supportive attitude to MSM. In addition, the related factors led to different self-reported sexual behaviors among the pMSM. Those pMSM might be likely to self-report as MSM who had never married, living in central downtown, finding HIV positive by VCT approach, without heterosexual partners, whose first CD4 results ≥200 cells/μl, keeping supportive attitude to MSM (p < 0.05).Next, we also analyzed the potential correlations for the socio-demographic characteristics and attitudes toward MSM among the three classes of pMSM by using the Chi-square test. Our data as shown in p < 0.05). Expectedly, self-reported MSM were more likely to have regular partners before HIV diagnosis .In total, 162 pMSM disclosed their same-sex behaviors in the survey. The mean age of the first same-sex behavior was 24.4 ± 7.5 years old. Our data as shown in n = 108) with medical care-reported MSM (n = 54). Multivariate modeling demonstrated that compared to surrounding county, pMSM from suburbs were more likely to disclose their same-sex behaviors only after receiving medical care, with adjusted ORs (αOR) of 7.37 (95%CI:1.61–33.71). In addition, pMSM who reported HIV infection via Provider Initiated HIV Testing and Counseling (PITC) were more likely to disclose their same-sex behaviors only after receiving medical care, compared to Voluntary Counseling and Testing (VCT) . Compared to self-reported MSM, the likelihood of condom use among medical care-reported MSM was lower   .n = 54) and self-reported heterosexual men (n = 28) were analyzed to explore the factors associated with deep non-disclosure of same-sex behaviors. Multivariate modeling data demonstrated that compared to surrounding counties, pMSM from suburbs had a high probability to disclose their same-sex behaviors after medical care, with adjusted ORs (αOR) of 0.04 (95%CI:0–0.42). However, these pMSM with a monthly income ≥3,000 RMB before HIV diagnosis usually concealed their same-sex behaviors even under medical care . Furthermore, in contrast to supportive attitudes, pMSM with neutral or un-supportive attitudes probably concealed their same-sex behaviors even if receiving medical care   .This investigation consisted of 190 pMSM samples, and we observed that 43.2% of pMSM surveyed had not disclosed their same-sex behaviors to HCPs during the first-self-report, 28.4% probably disclosed their sexual behaviors or history of risky behaviors to HCPs after receiving medical care, and 14.7% had not disclosed their situation even if receiving medical care. There might be a fraction of heterosexual men who entered the MSM transmission cluster because of the female partners who had sex with bisexual MSM, such as a heterosexual wife of MSM . But it Similar to other domestic studies , 28, ourvia PITC were more likely to disclose their same-sex behaviors only after medical care. This indicated that the disclosed MSM were more likely to receive VCT service, suggesting the importance of promoting disclosure of same-sex behaviors in medical services. A study confirmed that unprotected anal intercourse was more prevalent among non-disclosed MSM  was associated with disclosure of their same-sex behaviors even after medical care, being different from another study . pMSM wiOur study has several limitations. First, as some pMSM did not complete our survey and the data of the non-completers was excluded from our analysis, there might have been a selection bias as non-completers and participants might have had different socio-demographic characteristics and behaviors. And it also led to a decrease in the sample size of the study. Second, in the survey, we needed to ask about some pre-diagnostic behaviors, but the time of confirmed HIV positivity of every pMSM was different and it might lead to some recall bias because the length of recall varied across participants. Finally, as most collected data, especially the behavioral information, were self-reported, reporting bias might be present.Our study found that 43.2% of pMSM concealed same-sex behaviors to HCPs during the first-self-report and 14.7% continued to non-disclose after receiving medical care. In addition, our study demonstrated that same-sex behavior disclosure to HCPs was correlated with current address, income before diagnosis, and high-risk sexual behaviors and attitudes toward MSM. Non-disclosure of same-sex behaviors to HCPs also led to low acceptance of certain medical services. For example, non-disclosed MSM were less likely to receive VCT service. Thus, policies facilitating MSM to disclose their same-sex behaviors are recommended, such as legislations protecting homosexual rights on employment, education, marriage, and so on.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.This study was reviewed and approved by the Ethics Committees of the Sichuan Center for Disease Prevention and Control under recording number SCCDCIRB2022-008. All participants were asked to verbally express their understanding and consent to the study. All methods were performed in accordance with the relevant guidelines and regulations.LZ, LS, and JC conceived and designed the study. LZ, YZh, TY, FK, XH, and MH were involved in the data collection. LZ and YZh analyzed the data and wrote the initial draft. YZe, QW, CZ, and SL provided critical comments. LS and QW provided constructive comments and revised the manuscript before submission. All authors contributed to the article and approved the submitted version.This study was supported by the Sichuan Province Science and Technology Support Program (2017JY0302). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Bacteria in the dental biofilm produceacid after consumption of carbohydrates which if left unmonitored leads to caries formation. We present O-pH, a device that can measure dental biofilm acidity and provide quantitative feedback to assist in oral health monitoring.in vitro on additional buffered solution, artificial, and extracted teeth. An in vivo study on 30 pediatric subjects was performed to measure pH before (rest pH) and after (drop pH) a sugar rinse, and the resultant difference in pH (diff pH) was calculated. The study enrolled subjects with low (Post-Cleaning) and heavy (Pre-Cleaning) biofilm load, having both unhealthy/healthy surfaces. Further, we modified point-based O-pH to an image-based device using a multimode-scanning fiber endoscope (mm-SFE) and tested in vivo on one subject.O-pH utilizes a ratiometric pH sensing method by capturing fluorescence of Sodium Fluorescein, an FDA approved chemical dye. The device was calibrated to a lab pH meter using buffered fluorescein solution with a correlation coefficient of 0.97. The calibration was further verified We found significant difference between Post-Cleaning and Pre-Cleaning group using drop pH and diff pH. Additionally, in Pre-Cleaning group, the rest and drop pH is lower at the caries surfaces compared to healthy surfaces. Similar trend was not noticed in the Post-Cleaning group. mm-SFE pH scope recorded image-based pH heatmap of a subject with an average diff pH of 1.5.This work builds an optical pH prototype and presents a pioneering study for non-invasively measuring pH of dental biofilm clinically. I.CHRONIC caries in teeth, commonly known as tooth decay, is the most prevalent health condition affecting 2.3–3.5 billion people globally , [2]. UnThese dental tools and procedures provide patients with lagging, non-quantitative feedback assisting inadequately in prevention of new caries or in evaluating site-specific risk of caries development. In spite of oral care playing a significant part of a healthy daily routine, from brushing twice a day, frequent flossing, avoiding foods with excessive sugar, and minimizing snacks in-between meals, in addition to bi-annual dental visits, patients are still unable to evaluate effectiveness of their daily oral-care. Dentists, on the other hand, can’t objectively confirm if the patients, especially adolescents, are performing effectively their daily care routine unless a suspicious spot is clinically evident. There is a need to interject this present cycle of waiting-and-watching for a lesion to appear, in order to evaluate oral well-being using tools that can provide leading indicators for oral health. A leading indicator, a terminology commonly used in occupational health systems , provideStreptococcus mutans, etc.) , i, iStrepts, etc.) , 12] an anStrept ..30].et al. , ,  have hadFurther, as saliva pH also plays a role in caries formation , anotherin vitro studies using buffered fluorescein solutions and pH meter. In vitro study to understand sugar response using lab grown biofilm was not performed. Alternatively, resting pH could be verified in vitro by collecting biofilm from the subject’s mouth and measuring pH after dilution with water. But this method was not adopted as it would have caused disruption of dental-biofilm and also reduced the number of spots to measure drop pH in the mouth. Lack of micro-electrodes approved for intra-oral use in United States limited our study from verifying O-pH’s accuracy in vivo. Micro-electrodes measure pH at the saliva/biofilm interface and isn’t an ideal ground truth for O-pH that measures pH of extracellular oral biofilm. Microelectrodes, as previously mentioned is a contact based approach and could have caused disturbance in the biofilm impacting readings with O-pH. Therefore our approach for verifying the O-pH performance in vivo was based on comparison to prior studies that used pH measurement systems in research settings, as well as demonstrating acceptable repeatability of multiple measurements from the device.The accuracy of O-pH was verified with Although O-pH has the potential to be non-contact and thus nondestructive to the dental biofilm, this current spot-based pH sensing has clear drawbacks, especially in reliably testing the same spot before and after a sugar rinse. The lack of replicability in probe placement directly impacts the accuracy of pH drop measurements and has been identified as a source of variability in previous microelectrode measurements . Imaginget al. , [et al.  have shoV.O-pH measures acidification of the dental biofilm which is a critical step in the caries process, unlike indirect optical methods that rely on the presence of specific bacterial species in the biofilm. The device is capable of measuring pH of biofilm at occlusal pits and fissures and interproximal surfaces with repeatable measurements. Fast diffusion of sodium fluorescein dye into the biofilm enables measurement of pH inside the biofilm’s micro-environment rather than pH on the saliva surface. Additionally, the dye-based methodology allows measurement of extracellular pH without disturbing the biofilm. The initial clinical study with 30 subjects has shown O-pH’s capability to differentiate between low and high biofilm load in subjects using pH measurements. Future studies are needed to confirm its utility as a hygiene monitoring device and to measure pH trends within groups with low plaque load. We noticed, one of the drawbacks of a point-based device was uncertainty of probing the same region before and after a sugar rinse. This limitation was addressed by proposing an imaging-based pH monitoring device developed on the same principle as O-pH and tested on one subject. mm-SFE scope results indicated its ability to track rest and drop pH with images. Further clinical studies are needed to evaluate its usability, sensitivity, and accuracy. O-pH and mm-SFE scope are a step towards development of tools that can break the cycle of lagging dental indicators by providing site-specific trends that monitors direct bio-chemical properties affecting enamel health.


To evaluate the frequency of antibiotic prescribing for common infections via telemedicine compared to face-to-face visits.Systematic literature review and meta-analysis. estimation and the Cochran Q statistic test.We searched PubMed, CINAHL, Embase (Elsevier platform) and Cochrane CENTRAL to identify studies comparing frequency of antibiotic prescribing via telemedicine and face-to-face visits without restrictions by publish dates or language used. We conducted meta-analyses of 5 infections: sinusitis, pharyngitis, otitis media, upper respiratory infection (URI) and urinary tract infection (UTI). Random-effect models were used to obtain pooled odds ratios (ORs). Heterogeneity was evaluated with I = 31%) and pharyngitis . We detected no significant difference in the frequencies of antibiotic prescribing for sinusitis , URI , or UTI .Among 3,106 studies screened, 23 studies  were included in the systematic literature review. Most of the studies (21 of 23) were conducted in the United States. Studies were substantially heterogenous, but stratified analyses revealed that providers prescribed antibiotics more frequently via telemedicine for otitis media (pooled odds ratio [OR], 1.26; 95% confidence interval [CI], 1.04–1.52; ITelemedicine visits for otitis media and pharyngitis were associated with higher rates of antibiotic prescribing. The interpretation of these findings requires caution due to substantial heterogeneity among available studies. Large-scale, well-designed studies with comprehensive assessment of antibiotic prescribing for common outpatient infections comparing telemedicine and face-to-face visits are needed to validate our findings. Thus, targets of antimicrobial stewardship programs (ASPs) should also focus on outpatient antibiotic prescribing.In the United States, ∼60% of antimicrobial expenditures are associated with the outpatient setting, Before the coronavirus disease 2019 (COVID-19) pandemic, telemedicine was relatively uncommon in the United States, although its use was gradually increasing. However, since the beginning of the COVID-19 pandemic, telemedicine use has rapidly increased. Although telemedicine could provide an effective and safer alternative to face-to-face visits in many clinical contexts during the pandemic, there is not enough evidence of how provider antibiotic prescribing varies according to the mode of care delivery. Diagnostic uncertainty may increase for some infections because reliable physical examination and diagnostic tests are not always available via telemedicine. Providers may overprescribe antibiotics via telemedicine due to anxiety about missing bacterial infections. Furthermore, patients’ demand for antibiotics and providers’ perceptions of this demand may be different via telemedicine. Previous studies have suggested that telemedicine was associated with increased antibiotic prescribing. One systematic review conducted in early 2020 suggested an association between telemedicine and outpatient antibiotic prescribing in primary care settings. However, the study results were mixed and too heterogeneous to conduct a meta-analysis. Additionally, that study excluded ambulatory care settings other than primary care.Telemedicine is the provision of health care remotely using various telecommunication tools such as phone visits or mobile devices with or without a video connection.To address this knowledge gap, we conducted a systematic literature review and meta-analysis of the frequency of outpatient antibiotic prescribing via telemedicine versus face-to-face visits by including all visit settings not limiting to primary care settings to better describe variations in antibiotic prescribing according to the mode of care delivery (PROSPERO registration no. CRD42021228585). and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Search strategies were developed with the assistance of a health sciences librarian with expertise in searching for systematic reviews in December 2020 and January 2021. The literature search included publications from database inception to January 15, 2021. Comprehensive strategies, including both index and keyword methods, were devised for the following databases: PubMed, CINAHL, Embase (Elsevier platform) and Cochrane CENTRAL. To maximize sensitivity, no pre-established database filters were used. The full PubMed search strategy (Supplementary Table 1 online) was adapted for the other databases. In addition to the database searches, references of 14 relevant papers were located using the Scopus database. Publications were included if they evaluated the frequency of antibiotic prescribing in outpatient settings via telemedicine. Studies were excluded if they did not have a control group . Titles and abstracts of the studies identified by the initial literature search were screened (by H.S.) to assess inclusion criteria. The authors of 6 studies were contacted to provide additional information needed for meta-analysis. Among them, 1 author provided additional information, and that study was included in the meta-analysis.This systematic literature review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statementOf 3 independent reviewers , 2 abstracted data for each article using a standardized abstraction form. The reviewers abstracted data on publication year, study location, study setting, study design, study period, inclusion of adults and/or children, type of telemedicine, type of face-to-face visits, infectious diagnoses for which antibiotics were indicated, a definition of guideline-concordant antibiotic management, and an assessment of the potential risk of bias. Our primary outcome was the frequency of antibiotic prescribing via telemedicine and face-to-face visits, defined as the proportion of total visits in which an antibiotic was prescribed. As a secondary outcome, we evaluated guideline-concordant antibiotic management. We decided to conduct meta-analyses for individual diagnoses but not all diagnoses together. All questions of the original Downs and Black scale were answered as intended except a categorical question that we changed to a dichotomous answer for convenience. The maximum score was 28 points. Studies that scored 18 points or more were considered high quality. For data abstraction and quality assessment, inconsistent assessments were resolved by discussion.The risk of bias was assessed by independent reviewers using the Downs and Black scale. estimation and the Cochran Q statistic test. We used the Cochrane Review Manager (Revman) version 5.4 . Publication bias was assessed using funnel plots.To estimate the pooled odds ratio (OR) and 95% confidence interval (CI) for each infection, we used random-effects models with inverse variance weighting. We performed stratified analyses by the modes of telemedicine, location of face-to-face visits, adults or children, year of publication, and risk of bias according to the Downs and Black scale. Heterogeneity was evaluated with I 2 were cross-sectional studies, 1 was a case–control study, and 1 was a randomized controlled trial , which was reported in 6 studies, urinary tract infection (UTI), which was reported in 5 studies, pharyngitis, which was reported in 5 studies, and otitis media, which was reported in 4 studies. Finally, 15 studies earned 18 points or more in the Downs and Black scale and therefore were considered high-quality studies (Supplementary Table 2 online).The most commonly evaluated indication was sinusitis, which was reported in 10 studies, In total, 1,033 patients  with otitis media were treated via telemedicine and 71,919 patients  were treated via face-to-face visits. Antibiotic were prescribed for 67.3% of telemedicine and 59.3% of face-to-face visits, respectively. Among these 4 studies, 3 studies used claims-based data. Also, 2 studies found more antibiotic prescribing via telemedicine and the other 2 studies did not find a significant difference between the 2 modalities. When those 4 studies were analyzed by meta-analysis, telemedicine use was associated with significantly more antibiotic prescribing compared to face-to-face visits  with mild-to-moderate heterogeneity   with pharyngitis were treated via telemedicine and 66,841 patients  were treated via face-to-face visits. Antibiotics were prescribed for 63.4% of telemedicine visits and 61.3% of face-to-face visits. Furthermore, 2 studies found more antibiotic prescribing via telemedicine, and the other 3 studies did not find a significant difference between the 2 modalities. Those 5 studies were highly heterogenous . When limited to more recent studies conducted in 2018 and after, studies were homogenous , and telemedicine was associated with more antibiotic prescribing compared to face-to-face visits   with UTI were treated via telemedicine, and 5,815 patients  were treated via face-to-face visits. Antibiotics were prescribed for 85.4% of telemedicine and 62.6% of face-to-face visits, respectively. Those 4 studies were highly heterogenous . When the analysis was limited to 3 high-quality studies, studies were homogenous , and there was no significant difference in antibiotic prescribing between telemedicine and face-to-face visits   and urine culture (0%–7% in telemedicine and 21%–73.1% in face-to-face visits) were utilized less frequently in telemedicine.Four observational studies were included in the meta-analysis for UTI. In total, 21,640 patients  with sinusitis were treated via telemedicine visits and 588,749 patients  were treated via face-to-face visits. Antibiotics were prescribed for 64.8% of telemedicine and 65.9% of face-to-face visits, respectively. The association between antibiotic prescribing and telemedicine compared to face-to-face visits varied among studies. Also, 5 studies reported more antibiotic prescribing in face-to-face visits; 2 studies reported more antibiotic prescribing in telemedicine; and 3 studies did not find a statistically significant difference. Those 10 studies were highly heterogenous . When studies were limited to 4 high-quality studies that used synchronous telemedicine, studies were still moderately heterogeneous , and no statistically significant difference in antibiotic prescribing was observed between telemedicine and face-to-face visits   with URI were treated via telemedicine and 838,116 patients  were treated via face-to-face visits. Antibiotics were prescribed for 39.9% of telemedicine visits and 29.2% of face-to-face visits, respectively. The association between antibiotic prescribing and telemedicine compared to face-to-face visits varied among studies. In addition, 4 studies reported more antibiotic prescribing in telemedicine, 1 study reported more antibiotic prescribing in face-to-face visits, and 1 study did not find a statistically significant difference. Studies were highly heterogenous, and stratified analyses did not identify any homogenous subgroups .Six observational studies evaluated antibiotic prescribing for patients with URIs between telemedicine and face-to-face visits. Guideline-concordant management was assessed by the choice of guideline-concordant antibiotics in 4 studies, and antibiotic prescribing only for complicated sinusitis (diagnosed based on history) in 1 study. Also, 2 studies found more guideline-concordant management in telemedicine, 1 study found more guideline-concordant management in face-to-face visits, and another 2 studies did not find a significant difference between the 2 modes of delivery. These 5 studies were highly heterogenous . When the analysis was limited to 3 high-quality studies, there was moderate heterogeneity , and telemedicine use was associated with significantly more guideline-concordant management  . Aside from studies with extreme odds ratios (<0.2 or >5), studies were reasonably balanced around the pooled odds ratios, and studies with null results were included. Thus, there was little evidence of publication bias.We assessed publication bias by creating funnel plots for studies evaluating each diagnosis   of patients with URI received antibiotics even though antibiotics are almost never indicated for URI, indicating room for improvement in future ASP activities.Contrary to pharyngitis and otitis media, we did not observe a significant difference in antibiotic prescribing for patients with sinusitis or URI when care was delivered during telemedicine or face-to-face visits. For the management of sinusitis, antibiotics are only indicated in cases of severe disease, worsening course, or persistent illness, which can be differentiated with clinical history alone without the need for physical examination or diagnostic tests. Therefore, it is not surprising that there was not a significant difference in antibiotic prescribing between telemedicine and face-to-face visits. On the other hand, the appropriateness of treatment may be affected by the mode of care delivery because significantly fewer urinalyses and urine cultures were ordered during telemedicine visits. Interestingly, 2 studies that evaluated either first-line antibiotics or guideline-recommended antibiotics showed that telemedicine provided more appropriate treatment. Moreover, studies that investigated revisit as a marker for treatment failure did not report an increase in revisiting after a telemedicine encounter. Although it is possible that telemedicine can provide similarly effective but lower-cost care for UTI, this hypothesis will need to be validated by future studies.We did not detect a significant difference in antibiotic prescribing for patients with UTI in our meta-analysis. UTI is a diagnosis for which treatment with antibiotics is almost always indicated. Third, there may be some bias due to lack of information for inclusion in meta-analysis. We asked the corresponding authors of 6 studies to provide additional information, but we could include only 1 study with additional information. Fourth, many of the included studies had significant imbalance in sample size between telemedicine and face-to-face visits. Unmeasured biases may have affected the selection of patients seen via telemedicine. Finally, we did not fully investigate the appropriateness of treatment and follow-up of care, which are also very important components in assessing care variation between telemedicine and face-to-face visits. It is challenging to assess appropriateness of antibiotic prescribing using a retrospective study design without extensive chart review.Our systematic literature review and meta-analysis have several limitations. First, due to the heterogeneity among studies, our findings should be interpreted with caution. The studies varied in the study settings, population, and type of telemedicine and face-to-face visits. Due to the heterogeneity among studies, we elected not to perform a meta-analysis including all diagnoses but rather to conduct meta-analyses for each diagnosis. We also tried to determine the sources of heterogeneity by conducting several stratified analyses, but we could not conduct some of the stratified analyses due to the limited number of studies. Therefore, it is possible that there remained substantial residual heterogeneity. Although we acknowledge this limitation, we believe our findings will provide very important preliminary information for future studies. Second, most of the included studies used administrative codes to identify infections without confirmation by chart review. Administrative codes are not always accurate, but the reported positive predictive values for common infection such as pharyngitis or bronchitis were fairly good, ∼80%. As we expect continued high-volume use of telemedicine in outpatient settings, it would be very important to correctly understand how telemedicine affects antibiotic prescribing. To validate or further investigate our preliminary findings, large-scale, well-designed studies with comprehensive assessments of antibiotic prescribing for common outpatient infections will be warranted.The use of telemedicine may change after the COVID-19 pandemic has been controlled, but the adaptation trajectory of these technologies has been forever changed.In conclusion, our systematic review and meta-analysis found that telemedicine visits were associated with higher rates of antibiotic prescribing in some diagnoses, such as otitis media and pharyngitis. It seemed that providers overprescribed antibiotics for patients with diagnoses where antibiotics were not always indicated via for both modes of delivery. The interpretation of these findings requires caution due to substantial heterogeneity among available studies. Large-scale, well-designed studies with comprehensive assessment of antibiotic prescribing for common outpatient infections comparing telemedicine and face-to-face visits are needed to validate our findings.


In this paper, we present a historical review of the whistle-smile reflex, a semiological sign missed in the literature and clinical practice. Video 1The whistle-smile reflex. The patient and the healthy person gave us written consent to use their images.https://www.arquivosdeneuropsiquiatria.org/wp-content/uploads/2022/08/ANP-2022.0120-Video.movIn 1943, Frederic Hanes described the whistle-smile reflex, also known as Hanes sign: when asked to whistle, a healthy person does so and then smiles after the unusual physician's request. Otherwise, a patient with parkinsonism performs the whistle but does not smile after whistling due to the facial bradykinetic movementDr. Hanes was a neurologist and professor of medicine at Duke University. During his many years in Durham, North Carolina, he explored the presence of hypomimia as a semiological tool for the diagnosis of Parkinson disease (PD); finding, during his evaluations, what he considers a helpful and reliable sign.Lack of facial expression is a well-known feature of parkinsonian syndrome and an essential clue to diagnosing PD. Although James Parkinson did not mention hypomimia in his seminal work “An Essay on the Shaking Palsy”The whistle-smile reflex, alongside the Rolex sign


About half of all medical devices in low- and lower-middle-income countries are currently non-operational because equipment maintenance is lacking. Thus, choosing a cost-efficient equipment maintenance approach has the potential to increase both the quantity and quality of important health services. Between 2010 and 2014 Nepal’s Ministry of Health chose two of its development regions to pilot the contracting-out of maintenance services to the private sector. We develop a cost model and employ different data to calculate the cost of this contracted-out scheme. The latter we compare with two additional common approaches to maintenance: in-house maintenance and no maintenance.We use invoiced pilot program costs, device depreciation estimates from the literature, and hospital case numbers from Nepal’s Health Management Information System. We estimate net-present values for a three-year horizon, incorporating both fixed and operational cost. Operational costs include downtime cost measured as lost revenues due to non-working equipment.The contracted-out maintenance scheme shows a strong relative cost performance. Its cost after 3 years amount to 4,501,574 International Dollars Purchasing Power Parity (I$ PPP), only 90% of the cost with no maintenance. The contracted-out scheme incurs 670,288 I$ PPP and 3,765,360 I$ PPP in fixed cost and operational cost, respectively. The cost for replacing broken devices is 1,920,467 I$ PPP lower with maintenance. In addition, after 3 years total cost of contracted-out maintenance is 489,333 I$ PPP (11%) below total cost of decentralized in-house maintenance. After 10 years, contracted-out maintenance saves 2.5 million I$ PPP (18%) compared to no maintenance.We find that contracted-out maintenance provides cost-efficient medical equipment maintenance in a lower-middle income context. Our findings contrast with studies from high- and upper-middle-income countries, which reflect contexts with more in-house engineering expertise than in our study area. Since the per hospital fixed cost decrease with scheme size, our results lend support to an expansion of contracted-out maintenance to the remaining three development regions in Nepal.The online version contains supplementary material available at 10.1186/s12913-022-08392-6. Modern medicine is unthinkable without medical devices, such as X-rays, ultrasound machines or microscopes. They facilitate the prevention, diagnosis, and treatment of illnesses and as such directly affect human lives. At the same time, the acquisition and ownership of medical devices is expensive – including considerable cost of maintenance – and competes with other investments targeted towards quality health care provision. Choosing the right approach to manage and maintain medical equipment thus might come with substantial efficiency and performance gains for a country’s health care system . HoweverIn addition, scientific evidence on the performance and effects of medical equipment maintenance schemes in low and lower-middle income countries is scarce. A set of studies investigates the current state of equipment maintenance by building up inventories and conducting expert interviews to assess equipment operability and qualitative maintenance management recommendations , 5, 7–9.Thus, our paper focuses on the cost dimension and aims to provide novel evidence on several research gaps. First, it provides the first detailed cost analysis of a contracted-out medical equipment maintenance scheme covering multiple hospitals in a lower-middle income country context. Second, it includes the first – albeit hypothetical - comparative cost efficiency assessment of the three most common maintenance modes: contracted-out, in-house, and no maintenance. Last, this study makes a methodological contribution by including downtime cost into the equation. We use a simple costing model with fixed, operational, and downtime cost to estimate the net present value under these three different maintenance scenarios.Nepal, the context of this study, provides a showcase for the successful stepwise adaption of a maintenance management system, covering medical equipment of medium complexity (such as X-ray and ultrasound). Based on an initial equipment inventory and external donor support, the government delegated responsibility for equipment maintenance services, as well as trainings for in-house staff, to a private contractor. Before the adaptation of the maintenance system, non-operational devices were simply replaced with new equipment, which is still the reality in many low-income countries.In the fiscal year 2009/10, Nepal’s Ministry of Health operated 65 primary care hospitals  and 27 higher level hospitals  . The pubIn addition, the contractor’s service package covered maintenance of cold chain equipment in district health offices and equipment-related training to hospital staff. Inventory management and procurement of new devices remained under the responsibility of the Ministry of Health. In total, the contractor engaged 14 employees on this job , of which the majority  was assigned to one of the two regional maintenance workshops, in Nepalgunj (Mid-West) and Danghadhi (Far-West). Biomedical engineering technicians were trained at BMET Training Centre in Kathmandu and provided the first line of service, by moving between workshops and hospital facilities as required. Biomedical engineers provided backstopping. Job assignments were decided by the respective workshop manager as per maintenance schedule, job urgency and expertise required.During the mobilization phase, the contractor visited all hospitals for a thorough inspection and the creation of a final list of devices. Maintenance activities over the contract period of three years included six semi-annual maintenance visits for non-critical devices. Critical devices  received three preventive maintenance visits per year. In addition, the contract included the provision of corrective maintenance services, with different support response rates being offered for critical and non-critical devices. To monitor maintenance activities and payments, the Physical Asset Management unit centrally established a digital maintenance management information system (MMIS) prior to the mobilization phase. It records all maintenance and repair activities through the continuous collection of so-called “jobcards” and thereby provides an up-to-date device inventory.Nepal’s Health Management Information System (HMIS) collects a wide range of health provider information on a regular basis. It reports monthly data on patient numbers, services delivered, and performance indicators for all public health facilities. The data management unit of the Ministry of Health gathers and publishes HMIS data to facilitate administrative procedures and to inform policy decisions. Our data contain case numbers of six equipment-based health services, which we extract for the two reporting rounds 2008/09 and 2014/15  of 5%. Prices were adjusted for inflation and local currencies, and converted into I$ PPP using the World Bank’s World Development Indicators ). In the absence of any maintenance  and 359,767 I$ PPP (9.6%) less than for in-house maintenance after three years. In-house maintenance includes building a workshop and equipping it with tools, accumulating to about 799,855 I$ PPP. Maintenance cost includes technical in-house staff and requires hardware costing about 474,205 I$ PPP. Thus, the cost difference between contracted-out and in-house maintenance is mainly driven by the much higher cost of salaries and spare parts of in-house maintenance.To put the total numbers in context, we break down cost to the hospital level. To this end we assume that all fixed and operational costs are equally shared by the number of district hospitals and accordingly divide total program costs by the number of 19 district hospitals. Again, we consider the net-present value over a three-years period. According to Table ACalculating program cost for a longer time horizon provides a second extension to our main analysis. Figure For our study setting in Nepal, contracted-out maintenance shows the highest cost efficiency across three analyzed medical equipment maintenances modes. Its cost advantage mainly stems from lower operating cost, thus, the cost advantage of contracted-out maintenance increases with program duration. Similarly, contracted-out maintenance’s relative cost advantage likely increases further when geographically upscaling the program.In our study we emphasize the importance of incorporating downtime cost into the analysis when comparing scenarios with different outcomes . The empThis study is the first comprehensive costing study of medical equipment maintenance in a resource-constrained country. The quantitative literature on medical equipment in low- and lower-middle-income countries is very limited; most studies either provide simple equipment inventories or purely qualitative attempts to explore maintenance practices , 7–9. HoOur findings on the comparative advantage of contracted-out over in-house maintenance contradict similar studies within an university hospital setting in the United States and Brazil , 22. BotIt is important to note the following limitations of our study. First, we were not able to directly measure the difference in lifetime between well-maintained and non-maintained devices. As often the case in resource-constrained settings, Nepal has established an asset management inventory on medical equipment very recently and the pilot was too short to track changes in equipment lifetime . To thisAs with many empirical studies, a final limitation is that some of our results might not be easily applicable to other circumstances. The pilot catchment area covers only about seven million people, roughly one quarter of Nepal’s total population. Due to its relatively low operational cost, we expect contracted-out maintenance to perform even better when being scaled up to the country level. This motivates the cost evaluation of Nepal’s country-wide contracted-out maintenance scheme, which has been implemented in 2016, for future research. It is worth noting that Nepal’s terrain, with many hard-to-reach areas, may constitute a case where maintenance cost is relatively high compared to other countries.To summarize, it is remarkable that contracted-out maintenance has by far the lowest cost, even when initial investments are considered, while reducing equipment downtime. Thus, this study confirms contracted-out maintenance as a cost-efficient tool to increase equipment availability in health facilities for resource-constrained settings. Future studies would benefit from using country-specific databases on equipment lifetime. In addition, further research may widen the scope by looking into the role of in-house staff training and the central Physical Assets Management Policy .Additional file 1. Data sources, assumptions, and robustness checks. Information on data sources , assumptions (Table A2 & A3), robustness checks , and additional results (Tables A4 & A8).Additional file 2. Full cost calculations and formatted data. Detailed steps of the cost calculation and all data needed for replication in pre-processed format.


Additive manufacturing (AM) has grown and evolved rapidly in recent years. There are many exciting research and translational works in many areas of application, such as biomedical ,2, aerosIn this Special Issue, state-of-the-art research and review articles on emerging material systems for AM are collected, with a focus on the process–structure–properties relationships. In total, two reviews and thirteen original research articles are included. In their review article, Minasyan and Hussainova discussed the recent developments of ceramic particulate-reinforced aluminium alloys produced by laser powder bed fusion , while H


Island biogeography has classically focused on abiotic drivers of species distributions. However, recent work has highlighted the importance of mutualistic biotic interactions in structuring island floras. The limited occurrence of specialist pollinators and mycorrhizal fungi have been found to restrict plant colonization on oceanic islands. Another important mutualistic association occurs between nearly 15,000 plant species and nitrogen-fixing (N-fixing) bacteria. Here, we look for evidence that N-fixing bacteria limit establishment of plants that associate with them. Globally, we find that plants associating with N-fixing bacteria are disproportionately underrepresented on islands, with a 22% decline. Further, the probability of N-fixing plants occurring on islands decreases with island isolation and, where present, the proportion of N-fixing plant species decreases with distance for large, but not small islands. These findings suggest that N-fixing bacteria serve as a filter to plant establishment on islands, altering global plant biogeography, with implications for ecosystem development and introduction risks. Plants associated with nitrogen-fixing bacterial symbionts are disproportionately underrepresented on islands, suggesting that these bacteria might play a limiting role in island plant biogeography. One important group of mutualists that associate with plants is nitrogen-fixing (N-fixing) bacteria. In this symbiosis, N-fixing bacteria fix atmospheric nitrogen, with up to 90% used by the plant host6. These N-fixing mutualisms are major drivers of the global nitrogen cycle, producing up to 100 million tons of terrestrial nitrogen a year3, and have large effects on ecosystem development as nitrogen is often limiting in terrestrial systems, particularly on recently formed land such as oceanic islands7. While classical island biogeography has historically centered around the spatial and bio-physical drivers of plant distributions, it remains unclear whether co-colonization requirements of the two partners in this mutualism limit the establishment of N-fixing plants on distant islands.Mutualisms between organisms across the tree of life play a pivotal role in shaping the diversity and functioning of ecosystems. The plant kingdom, in particular, has harnessed symbionts to facilitate plant growth and survival across almost all environments on Earth. Plant mutualisms provide essential services and resources, from pollination to nutrient supply, drought resistance, and pathogen protection8. If this were the case, we would expect plant species associating with mutualists to colonize islands similarly to plant species not associating with these partners, as their colonization would not be limited by this biotic interaction. However, recent work has identified that plant-associated microbes can be dispersal limited, with cascading impacts on their plant hosts9. In particular, recent work suggests that biogeographical patterns of plants are consistent with the dispersal limitation of mycorrhizal fungi, particularly arbuscular mycorrhizal (AM) fungi, filtering out AM plant species on islands12. Whether N-fixing bacteria, the other major plant-microbial symbiont, could similarly limit island colonization by N-fixing plants remains unknown. Such a filter may be expected given that these bacteria can be poor dispersers and can show high specificity for their plant partners13. Alternatively, N-fixing bacteria could lead to a weak colonization filter as they are able to live saprotrophically14, allowing a greater time window between the arrival of the bacteria and the host plant. However, the large plasmid required for symbiosis is costly to maintain, resulting in strong selection against its’ persistence in absence of host plants15, again potentially generating a stronger colonization filter of N-fixing plants.Historically, microbes were assumed to be ‘everywhere’, or have a cosmopolitan distribution, with the environment being the major limiting factors of their realized niche18 such as those found on oceanic islands. In addition, limited colonization of N-fixing plant species could leave open niches on islands, with consequences for subsequent diversification. Initial filtering out of N-fixing plants may allow subsequent disproportionate diversification of N-fixing compared to non N-fixing plants. Such a pattern of increased diversification resulting in higher endemism for AM plants was observed following a strong colonization filter12, but this pattern remains to be tested for N-fixing plants.If present, this N-fixing symbiont filter could have important consequences for ecosystem development and diversification patterns. A reduced proportion of N-fixing plant species and their associated symbionts would be expected to contribute to slower development of island ecosystems over time, with slower accumulation of nitrogen through N-fixing bacteria. Thus, an N-fixing symbiont filter on islands could prolong the observed pattern of low nitrogen on younger soils17, it is possible that filters from these two symbionts act non-additively in limiting plant establishment on islands. Synergistic limitation, where plant species that associate with both types of symbionts are less likely to colonize islands than expected from the two filters individually, may occur given that synergistic effects on plant growth has been found for co-inoculation with mycorrhizal fungi and N-fixing bacteria21. However, meta-analyses suggest that synergistic impacts on plant growth may be limited to perennial plants23, which may reduce the likelihood of finding synergistic limitations on island colonization. To date, the possibility of a plant island colonization filter strengthened by multiple mutualisms has not been tested.Finally, as many plants that associate with N-fixing bacteria also associate with mycorrhizal fungi25 across 1005 locations to test for evidence of an N-fixing symbiont filter on plant colonization to islands. We further test if strength of this filter increases with island isolation as dispersal limitation of bacteria is likely to be highest on islands that are more distant from the mainland. In addition, to test if diversification relates to N-fixing status, we explore how these patterns interact with endemism. Finally, we ask if there is a synergistic effect between the mycorrhizal and N-fixing symbiont filter on plant colonization. We test these biogeographical patterns first using all vascular plant species and then within the legume family only. We examine legumes separately because these plants overwhelmingly associate with N-fixing bacteria, have multiple independent losses and gains of associations with mycorrhizal fungi26, and are of high economic and agricultural importance6. Together, this work tests for the generality of the microbial mutualism filter of plant establishment on islands worldwide. Understanding the impact of mutualisms on island plant establishment has important implications for the field of island biogeography, implicating biotic interactions as a pervasive control on plant distributions.Here, we use a global database of 209,189 plant species and their N-fixing statusWe find evidence for mutualistic limitation of plant establishment by N-fixing bacteria. Across all plant species, N-fixing plants are underrepresented by 22% on both non-oceanic and oceanic islands, consistent with the hypothesis of absence of N-fixing bacterial symbionts on islands limiting host plant establishment. We further find that the probability of N-fixing plant occurrence declines with distance from mainland, and, where present, the proportion of N-fixing plant species declines with distance for all but the smallest islands. Thus, despite tens of millions of years over which islands may accumulate N-fixing species, we detect evidence consistent with an N-fixing symbiont filter on plant establishment on islands worldwide.p < 0.001, Supplementary Table p = 0.11, Supplementary Table N-fixing plant species were underrepresented on islands of both non-oceanic and oceanic origin across all vascular plant species. Specifically, there was a decrease in the proportion of N-fixing plant species on oceanic islands compared to mainlands, representing a 21.5% decline in N-fixing plant species  by mycorrhizal fungi and N-fixing bacteria on plant establishment. We found that both filters act independently, with no evidence that plants that associate with both symbiont types are more strongly limited than expected from the two filters . This may be the result of greater heterogeneity on larger islands providing greater niche space, in turn supporting the diversification of more diverse plant assemblages.We do not find evidence for differential diversification of N-fixing species with distance from the mainland  was undetermined.Plant species occurrence data (for mostly administratively defined locations such as countries and provinces or islands), biogeographic status  and explanatory variables with characteristics were extracted from the Global Inventory of Floras and Traits v 1.0, GIFT database37, incorporating the classification from APG IV38. We used the N-fixing database of 9156 angiosperm species previously published by Werner et al.24, which identifies plant species that form nodules to house N-fixing bacteria . We first assigned N-fixing status (N-fixer or non N-fixer) based on species level status in the database. If the given species was not found, we then applied family-level proportions of plant species’ N-fixing status to assign status proportions to the locations’ plant species assemblages. Where neither species nor family was found in the database, species were removed from analyses. In total, we assigned 6,860 species using the N-fixing status database matching directly to species and an additional 202,329 species through family status proportions. We estimate the total number of N-fixing species in our dataset, and the most up to date estimate of N-fixing plant species globally, to be 14,553. Mycorrhizal status was assigned using the FungalRoot database39 using the same approach as for N-fixing assignment. That is, we first assigned mycorrhizal status based on species level status; if this was not possible, we applied genus-level proportions to plant species assemblages. Although there are several mycorrhizal types, we were primarily interested in the arbuscular mycorrhizal plant species, as these were previously shown to be underrepresented on islands12 and they represent the most common mycorrhizal type. Therefore, we only compared two mycorrhizal statuses: arbuscular mycorrhizal (AM) and all other mycorrhizal types, including non-mycorrhizal plant species (NM).The nitrogen-fixing (N-fixing) status of plant species included in this study was determined by assigning each species to its plant family according to The Plant List40. Explanatory variables included land type , absolute latitude and longitude of the location’s centroid, area (km²), mean annual temperature (°C) and mean annual precipitation41 (mm), and elevational range42 (difference between lowest and highest elevation in m). When elevation range was unknown or reported as zero from aerial elevation maps, we assigned an elevation of 1 m as a minimum necessary elevation. For islands, we also included island distance to the nearest mainland (km) as a measure of geographical isolation43 and island geological age. It is important to note that age reflects geological age, and not biological age, and therefore may not accurately reflect time from start of plant colonization. Data for endemism analyses represent a subset of islands for which endemism status was known.Explanatory variables for each location were extracted from the GIFT database. For details of environmental data collection, see Weigelt et al.To investigate patterns of native N-fixing plant distributions globally, we used several mixed models that correct for non-independence due to spatial proximity. First, for all native angiosperm species, and then legumes separately, we tested for overall differences in the proportion of N-fixing plant species between mainlands and islands. We were unable to test for presence in these models as N-fixing plant species were present on all mainlands. Next, for island floras, we tested for environmental drivers of the presence, with sites with a minimum of one N-fixing plant species labeled ‘present’, and proportion of N-fixing plant species for sites with N-fixing plant species present. We then tested for synergism of the N-fixing and mycorrhizal filters. Finally, we reran the island models to test for the proportion of N-fixing plant species among endemics.In our first set of models, we compared N-fixing plant species to non N-fixing plant species between land types (mainland or island). We used a composite response variable with species richness of N-fixing to non N-fixing plant species to account for differences in species richness. For these analyses, we used generalized linear models (GLMs) with a logit link function, assuming a binomial distribution of the response variable. The fixed effects were land type, absolute latitude, squared latitude, the natural logarithm of area, the natural logarithm of elevation, mean annual temperature and mean annual precipitation. We also included the random effect of location nested within land type. Random terms control for the non-independence of individual plant species records within floras, thereby providing general tests for differences in the proportion of N-fixing plant species across the floras of the different land types.44 as well as other island biogeographic studies46.Next, to investigate geographical and environmental drivers of N-fixing presence and proportion for native plants in oceanic island floras, we ran models comparing either the presence or proportion of N-fixing to non N-fixing plant species. For presence, the response variable was coded as a binary response variable, either the location had at least one N-fixing plant species (present), or it did not (not present). For proportion, we again used a composite response variable with species richness of N-fixing to non N-fixing plant species to account for differences in species richness. For these analyses, we used generalized linear models (GLMs) with a logit link function, assuming a quasi-binomial distribution of the response variable. We included the following explanatory variables: absolute latitude, squared latitude, the natural logarithm of area, the natural logarithm of elevation, mean annual temperature, mean annual precipitation and distance to mainland. We initially explored models with island age, however, as (1) this effect was not significant, (2) inclusion of this predictor substantially reduced the number of location s in the model, and (3) when testing for the best models, age was not included in all but one resulting model, we include results of models without island age in the manuscript. The choice of variables was informed by prior studies of their effects on this datasetTo test for synergism between N-fixing and mycorrhizal limitation, we predicted species counts using generalized linear models (GLMs). As covariates, we included N-fixing status (N-fixing or non N-fixing), mycorrhizal status (AM or NM), location, as well as the three-way interaction of these three covariates. A significant three-way interaction between N-fixing status, mycorrhizal status and land type would indicate evidence of synergistic limitation of plant establishment, with the counts of species associating with both symbionts being lower than that predicted from average filter effects of each symbiont individually. The random effects were location nested within land type, the interaction of location nested within land type with N-fixing status, the interaction of location nested within land type with mycorrhizal status, and the interaction of location nested within land type with N-fixing status and mycorrhizal status.Finally, we ran models testing for the proportion of endemic species in native oceanic island floras, using a composite response variable with counts of endemic species and non-endemic species. For these analyses, we used generalized linear models (GLMs) with a logit link function, assuming a quasi-binomial distribution of the response variable. As covariates, we included N-fixing status, absolute latitude, squared latitude, the natural logarithm of area, the natural logarithm of elevation, mean annual temperature, mean annual precipitation, and distance to mainland. We also tested for the interaction of N-fixing status with area and again with distance.46 in the spdep package in R47. Neighborhood distance were set to 1000 km and weighted by inverse distance; spatial coordinates are the site centroids, except for endemism models where we lightly staggered centroid locations due to paired rows per site. All analyses were done in R 3.4.148 in the lme4 package49.Where we detected overdispersion (Supplementary Tables Further information on research design is available in the Supplementary InformationDescription Of Additional Supplementary FilesSupplementary Data 1Reporting Summary


In its unique approach through open-ended data analysis contests, CAMDA in 2021 again highlighted key challenges in analysing massive data in the life sciences. Since its inaugural meeting at Duke University in 2000, CAMDA has become a major fixture  and runsThe increasing relevance of Big Data in the modern life sciences keeps CAMDA topical, addressing one of the grand challenges in the field. Improvements in both the productivity and accessibility of genome-scale assays together with the recognition that high-dimensional profiling requires large sample sizes are driving ever increasing data set sizes. Still, the data analysis bottleneck limits the rate with which new medical and biological insights can be found. CAMDA tackles this challenge head on, introducing and evaluating new approaches and solutions. Specifically, the conference presents new techniques in bioinformatics, data analysis, and statistics for large data sets, combining multiple data sources, and effective computational inference. Every year, unique data sets are compiled and selected, with multiple academic research groups analysing the same data competitively. The most insightful analyses are then selected by vote amongst the 100–200 researchers attending the CAMDA conference sessions.Dongyuan Wu et al. focus on the response of T cells to SARS-CoV-2. The authors detected pairwise differentially expressed genes by single-cell RNA-seq of CD4+ and CD8+ T cells, comparing a healthy control group to patients with either mild or severe COVID. A deep learning algorithm identified patterns of differentially expressed genes distinguishing the different disease states. The emerging co-expression networks for CD4+ T cells yielded 6 modules for healthy patients, 4 for mild disease, and 1 module for severe disease. For CD8+ T cells, they found 6, 4, and 3 modules. An identification of hub genes implicated TNF, CCL4, XCL1, and IFITM1 in the SARS-CoV-2 response. IFITM1 was already known to inhibit infection by enveloped viruses, including other coronaviruses. The newly identified networks thus yielded novel COVID related gene clusters and patterns of gene connectivity for further investigation. Further development of machine learning exploiting disease maps, molecular profiles, and patient data will continue to advance our understanding of disease mechanisms and support drug repurposing.One challenge this year sought insights on the molecular response to COVID-19. Delegates explored and combined existing mechanistic maps and large-scale expression profiles. We here present a highlight from that challenge, where www.fda.gov/about-fda/office-chief-scientist/national-center-toxicological-research, www.iarai.ac.at).In the development of novel drugs, however, unexpected Drug-induced liver injury (DILI) remains a major disruptor. In collaboration with the US-FDA, CAMDA has approached this topic from a range of complementary angles in recent years. DILI is an important class of adverse drug reactions. In fact, it is the most frequent cause of acute liver failure in many Western countries. Manual trawling of the literature is the main route of deriving information on DILI from research studies, yet this is an inefficient process that scales badly and is prone to human error. Therefore, hope has been placed in automated assistance by AI models identifying articles of likely relevance to DILI amongst the many million research articles published. We here report advances from the related CAMDA 2021 challenge. Training data were compiled with the help of the US-FDA NCTR and support by IARAI (Sanjay Rathee et al. apply customized token generation for word sets of varying lengths after standard NLP segmentation, lemmatization, and filtering. Superset patterns are identified from these word sets by a distributed a priori algorithm, with higher weights for the curated sources. Scores are then considered by an ensemble of classifiers in nested cross-validation. In another contribution by this group, Nicholas Katritsis et al. start by extracting mentions of chemical and disease terms via PubTator, and embed their TF-IDF representations with node2vec in the context of corpora derived from Chemical Checker, MeSH, and the Comparative Toxicogenomics Database. The neural network classifier exploiting these chemical and disease embeddings outperformed one based on text alone.Malik Yousef et al., in contrast, replace the traditional Bag-of-words approach with a Bag-of-topics. Topics are extracted by LDA, then topic-specific data sub-sets are generated and, based on these, topics are scored and ranked by Random Forest with Monte-Carlo stratified cross-validation. Finally, the best ranked topics are used in a bag-of-topics Random Forest classifier, outperforming comparable bag-of-word classifiers.All three papers achieved F1 scores in the range of 88%–91% on independent validation sets. Further tests with more imbalanced class distributions will facilitate real-world applications.An essential part of CAMDA, however, is its open-ended data analysis of complex data sets, often featuring novel technological platforms, exceptionally large cohorts, and heterogeneous data sources and types. Both contestants and other interested researchers are welcome at the meeting. In this context of fruitful debate, it is precisely its open-ended character that allows CAMDA to foster disruptive and innovative ideas, inspiring discussions and analysis ideas that go beyond the initial premises. Consequently, the winning CAMDA contributions are not already determined by algorithm performance but consider novelty and insights presented. This winner of CAMDA 2021 identified exciting new therapeutic leads for COVID by integrating the mechanistic disease map with the viral-human metabolic network, and these leads are currently being validated pre-clinically before publication of a manuscript in the CAMDA Proceedings. We are proud of this year’s Research Topic of papers.


Background: Epidermal growth factor receptor (EGFR) mutations are common in patients with non-small-cell lung cancer (NSCLC), particularly in Asian populations. Tyrosine kinase inhibitors (TKIs) are a first-line treatment in patients with mutant EGFR, but their use is often accompanied by drug resistance, which leads to disease progression. Chemotherapy and immunotherapy are the main treatment options after progression. The efficacy of immune checkpoint inhibitors (ICIs) and their combination therapy in patients with EGFR-TKI resistant is not clear. It is thus necessary to evaluate the efficacy of ICIs and ICI-based combination therapies in patients with EGFR-TKI-resistant NSCLC.Methods: We searched for randomized controlled trials (RCTs) comparing ICI therapy alone or in combination versus other therapies using PubMed, the Cochrane Library, Web of Science, EMBASE, MEDLINE, ClinicalTrials.gov, and several international conference databases, from database inception to 10 March 2022. The hazard ratio (HR) and 95% confidence interval (95% CI) for median overall survival (OS) and median progression-free survival (PFS) were evaluated. Odds ratio (OR), risk ratio (RR), and 95% CI were used as effect indicators for objective response rate (ORR) and safety data.Results: Seven eligible RCTs were included in the present meta-analysis. The results showed that neither ICIs nor combination therapy prolonged median OS in EGFR-TKI resistant NSCLC patients . However, compared with the control group, the patients treated with ICI-based combination therapy had better PFS  and ORR .Conclusion: ICI monotherapy did not improve the OS or PFS of NSCLC patients previously treated with EGFR-TKIs, whereas patients treated with ICI-based combination therapy had better PFS compared with those receiving conventional chemotherapy, indicating that this therapy could be offered to patients with EGFR-mutant NSCLC after progression following TKI treatment. There was no significant difference in all-grade treatment-related adverse events (TRAEs) between the combination therapy group and the control group. However, a higher incidence of discontinuation due to TRAEs was observed; this requires attention in future studies. The results of this meta-analysis provide a reference for clinical practice and future trial design.PROSPERO registration number: CRD42021282207 Lung cancer is the main cause of cancer death worldwide. In 2020, the number of deaths due to lung cancer accounted for about 18% of all cancer-related deaths , and theWith the development of targeted therapies, tyrosine kinase inhibitors targeting EGFR (EGFR-TKIs) have become a common treatment for patients with EGFR-mutant advanced NSCLC. TKI treatment has shown significant clinical efficacy compared with traditional chemotherapy. Studies have shown that EGFR-TKIs significantly prolonged the progression-free survival (PFS) and overall survival (OS) of patients , and mosImmune checkpoint inhibitors (ICIs) are a recently developed type of cancer treatment that has emerged in the past 10 years. Some studies have shown that patients with advanced NSCLC without driver gene mutation can benefit from immunotherapy . ImmunotWhether immunotherapy is suitable for advanced NSCLC patients with EGFR mutation has become a hot-button issue. In studies mentioned above, NSCLC patients with EGFR mutation have generally not benefited from immunotherapy. However, some studies have shown that a small number of patients can benefit from immunotherapy. In addition, there have been few reports on the applications of ICI-related combination therapy in EGFR-TKI-resistant patients. Therefore, the efficacy of ICIs in patients with EGFR-TKI-resistant NSCLC is unclear and needs to be further explored.The purpose of this meta-analysis was to evaluate the efficacy of ICIs alone and in combination therapies in patients with advanced NSCLC resistant to EGFR-TKI, so as to better address the problems associated with the use of ICIs in such patients.The present systematic review and meta-analysis was conducted following PRISMA guidelines . The prohttps://clinicaltrials.gov/), conference abstracts of American Society of Clinical Oncology, European Society for Medical Oncology, and World Lung Cancer Conference. The keywords searched included: “non-small cell lung cancer,” “immune checkpoint inhibitors,” “tyrosine kinase inhibitor,” “epithelial growth factor receptor,” and “randomized controlled trial”. The detailed inclusion and exclusion criteria are listed in We searched PubMed, the Cochrane Library, Web of Science, EMBASE, and MEDLINE. The retrieval time limit was from the establishment of each database to 10 March 2022. In addition to the above databases, in order to include unpublished studies and obtain more comprehensive relevant research data, we searched the clinical trial registration website , hazard ratio (HR), and 95% CI for median OS and median PFS.Two researchers (Q. X. and G. X.) independently screened the literature, and extracted and cross-checked the data. Discrepancies were resolved by the third researcher. Data types extracted from the trials were: trial phase, authors, year of publication, number of patients, number of patients with EGFR mutation, age of patients, gender of patients, number of smoking patients, treatment comparison, median OS, HR and 95% CI of median OS, median PFS, HR and 95% CI of median PFS, ORR, and safety data. All study periods and follow-up durations were eligible. Titles and abstracts were screened, and the full text of each potentially eligible article was evaluated for final inclusion.Statistical analysis in this study was performed using the Cochrane Review Manager (RevMan 5.4) software provided by the Cochrane Library Collaboration Network.The risk of bias of the study was assessed using the Cochrane bias risk assessment tool , which i2 index and q-statistics were used to evaluate the heterogeneity among studies. If I2<50%, p > 0.05, indicating that the research results may be homogeneous, the fixed effect model is used for analysis. In contrast, when I2>50%, p < 0.05, indicating substantial heterogeneity, the source of heterogeneity should be analyzed. If the heterogeneity still exists, the random effect model should be used.For the included studies, HR and 95% CI were used as effect indicators for median OS and median PFS, odds ratio (OR) and 95% CI were used as effect indicators for ORR, and risk ratio (RR) and 95% CI were used for safety data. IA total of 1118 relevant studies were retrieved according to the retrieval strategy. The literature was screened according to the exclusion criteria, and finally seven studies  were incOf the included patients, a total of 902 (21.01%) had known EGFR mutations and had received previous TKI treatment, with disease progression during or after treatment. Of the seven therapeutic regimens, three  were com2 = 0, p = 0.95) the heterogeneity among the studies was low. The results were pooled and analyzed by a fixed effect model. The results showed that there was no significant difference in median OS between the intervention group and the control group   , regardlp = 0.0002) (p = 0.004) (p < 0.00001)  . The poo= 0.004) . Subgrou0.00001) .Four of the seven studies reported the median PFS of patients, and three did not. Only one article reported ORR in the monotherapy group, so it was impossible to calculate the ORR of monotherapy. We only conducted a meta-analysis on the ORR of the combination group .p = 0.001). Subgroup analysis showed that ICI plus chemistry was beneficial with respect to ORR, but this benefit was not statistically significant. ICI plus anti-angiogenesis agents plus chemotherapy had better efficacy than ICI plus chemotherapy , grade ≥3 TRAEs , or TRAEs leading to discontinuation  (p = 0.70) and grade ≥3 TRAEs  between the combination therapy and chemotherapy groups; however, combination therapy was associated with more TRAEs leading to discontinuation  , grade ≥3 TRAEs, and TRAEs leading to discontinuation of included studies. Compared with traditional chemotherapy, ICI monotherapy did not cause more serious adverse reactions, whether all-grade TRAEs  . There w = 0.01) .2 = 0%, p = 0.94), median PFS  and ORR  among the included studies. The results obtained with the Cochrane risk-of-bias assessment tool for the seven enrolled RCTs are shown in As shown in This meta-analysis showed that in NSCLC patients with disease progression or recurrence after TKIs treatment, immunotherapy as second-line or third-line treatment confers no benefit with respect to OS and PFS compared with chemotherapy. However, chemotherapy resulted in better PFS in the patients with TKI treatment progress, consistent with previous research results . ICI-basp = 0.039), and the ORR was better (50% in combination group vs. 22% in chemotherapy group). Tian et al. found that the ICI-based combination therapy was better than ICI monotherapy, with median PFS values of five and 2.2 months and median OS values of 14.4 and 7 months, respectively. Bai et al. found that the ICI-based combination therapy prolonged the survival of patients, especially the regimen of immunotherapy plus chemotherapy plus antiangiogenetic agents. All of these studies showed that combination therapy was effective in patients with previous TKI progression, and the combination of immunotherapy plus chemotherapy plus antiangiogenetic agents was the most effective treatment.In order to further explore the efficacy of combined therapy, we systematically searched observational studies and found only three relevant studies. One of these studies compared the efficacy of chemotherapy plus ICIs with and without anti-angiogenic drugs and chemotherapy alone . HoweverIn terms of safety, ICI monotherapy did not show more serious toxicity overall compared with chemotherapy. There was no significant difference in frequency of all-grade TRAEs and grade ≥3 TRAEs between the combination treatment group and the control group. However, the incidence of adverse events leading to discontinuation in the combined treatment group was higher than that in the control group. The health status of patients should thus be closely monitored. The TRAEs of grade 3 or higher in the combination therapy group were mainly neutropenia, anemia, hypertension, and leucopenia, and no additional safety signals were found.Although studies have shown that PD-1/L1 inhibitors represent a promising treatment for patients with EGFR-TKI-resistant NSCLC, according to our meta-analysis, ICI monotherapy did not have a significant effect. The formation of blood vessels around the tumor is a possible reason for the lack of effectiveness of immunotherapy. Such neovascularization around the tumor forms a physical barrier that prevents the infiltration of immune cells into the tumor tissue. Tumor vascular endothelial growth factor (VEGF) also induces FasL expression and thus triggers T cell apoptosis; therefore, even if the ICI can activate more immune cells, it is difficult for these to have a considerable effect. Antiangiogenic agents can induce tumor vascular normalization by inhibiting VEGF, weakening the physical barrier of tumor angiogenesis, increasing the infiltration of immune cells, and further activating immune effector cells under the action of ICI, thereby improving the efficacy of immunotherapy. The infiltration of more immune effector cells promotes the release of interferon γ and vascular remodeling, which in turn improves the efficacy of angiogenic agents and forms a virtuous circle . FurtherA major advantage of this study is that it included data from all the latest relevant trials, including three outcome indicators from seven studies; it also included data on immune-related combination therapy for the first time. The study population was only composed of EGFR-mutant NSCLC patients who had received previous TKI treatment, which ensured the homogeneity of the study population to a certain extent. The results of this meta-analysis suggest that combination therapy may have a better therapeutic effect than immune monotherapy; the combination of ICIs and antiangiogenic agents in particular deserves further attention.There were many limitations of this meta-analysis. Only a limited number of trials were included in this study. As the subject matter has only become a research hotspot in recent years, many trials are still in progress. Several intention-to-treat studies have shown that ICI monotherapy is not effective, decreasing the research focus on ICIs monotherapy. Most current research focuses on ICI combination therapy ICIs in EGFR-TKI-resistant patients; in particular, ICIs combined with chemotherapy and ICIs combined with antiangiogenic agents have become a research hotspot. We have summarized the relevant RCTs in progress  to proviIn conclusion, compared with chemotherapy, ICI monotherapy as a second-line or third-line treatment did not significantly improve the survival of patients with EGFR-TKI resistant NSCLC according to the data analyzed. For patients with EGFR mutation, based on the reports included in this study, the expression state of PD-L1 does not have a significant impact on the effect of monotherapy. In PD-L1+ patients, combination therapy has shown good efficacy. Further investigation of the mechanisms of PD-L1 expression and drug resistance will help to guide subsequent immunotherapy. Combination therapy seems to play a better role than monotherapy; however, according to the results of our analysis, the efficacy of ICI combined with chemotherapy needs further study. The combination of ICIs with chemotherapy or antiangiogenic agents showed considerable efficacy. Owing to the limited sample size, the therapeutic value of this combination treatment scheme needs to be verified using more clinical trial data.ICI-based combination therapy could be used as a follow-up treatment option for patients with EGFR-TKI-resistant NSCLC, especially the combination of ICIs with chemotherapy or antiangiogenic agents. There was no significant difference in all-grade TRAEs between the combination group and the control group, but it should be emphasized that combination therapy was related to a higher incidence of TRAEs leading to discontinuation, which requires close attention. Furthermore, the treatment cost of the combination of three agents is relatively high, which will lead to fewer patients taking it as a follow-up treatment option. How to optimize the treatment strategy of ICI combination therapy to reduce toxicity and economic burden is a difficult problem to be overcome; more and larger-scale research is needed. Finally, it is worth mentioning that the reliability of meta-analysis results and their applicability in clinical practice depend on critical thinking and objective judgment.