Adaptive promising zone design for cancer immunotherapy with heterogeneous delayed treatment effect.

Indirect mechanisms of cancer immunotherapies result in delayed treatment effects that vary among patients. Consequently, the use of the log-rank test in trial design and analysis can lead to significant power loss and pose additional challenges for interim decisions in adaptive designs. In this paper, we describe patients' survival using a piecewise proportional hazard model with random lag time and propose an adaptive promising zone design for cancer immunotherapy with heterogeneous delayed effects. We provide solutions for calculating conditional power and adjusting the critical value for the log-rank test with interim data. We divide the sample space into three zones - unfavourable, promising, and favourable -based on re-estimations of the survival parameters, the log-rank test statistic at the interim analysis, and the initial and maximum sample sizes. If the interim results fall into the promising zone, the sample size is increased; otherwise, it remains unchanged. We show through simulations that our proposed approach has greater overall power than the fixed sample design and similar power to the matched group sequential trial. Furthermore, we confirm that critical value adjustment effectively controls the type I error rate inflation. Finally, we provide recommendations on the implementation of our proposed method in cancer immunotherapy trials.

Community ambulation in older adults and people with OA - a model verification using Canadian Longitudinal Study on Aging (CLSA) data.

BACKGROUND: There are health and well-being benefits of community ambulation; however, many older adults do not regularly walk outside of their home. Objectives were to estimate the associations between latent constructs related to community ambulation in older adults aged 65-85 (65+), and in adults with osteoarthritis (OA) aged 45-85. METHODS: Secondary data analysis of the comprehensive baseline and maintaining contact questionnaire data from the Canadian Longitudinal Study of Aging (CLSA) was completed. Based on a previous model of community ambulation post-stroke, structural equation modeling (SEM) was used to develop measurement and structural models for two groups: older adults 65+ and people with OA. Multi-group SEM was conducted to test measurement invariance across sex and age groups. Measurement models were developed for the following latent factors: ambulation (frequency of walking outside/week, hours walked/day, ability to walk without help, frequency and aids used in different settings); health perceptions (general health, pain frequency/intensity); timed functional mobility (gait speed, timed up-and-go, sit-to-stand, balance). Variables of depression, falls, age, sex, and fear of walking alone at night were covariates in the structural models. RESULTS: Data were used from 11,619 individuals in the 65+ group (mean age 73 years ±6, 49% female) and 5546 individuals in the OA group (mean age 67 ± 10, 60% female). The final 65+ model had a close fit with RMSEA (90% CI) = 0.018 (0.017, 0.019), CFI = 0.91, SRMR = 0.09. For the OA group, RMSEA (90% CI) = 0.021 (0.020, 0.023), CFI = 0.92, SRMR = 0.07. Health perceptions and timed functional mobility had a positive association with ambulation. Depression was associated with ambulation through negative associations with health perceptions and timed functional mobility. Multi-group SEM results reveal the measurement model was retained for males and females in the 65+ group, for males and females and for age groups (65+, < 65) in the OA group. CONCLUSIONS: The community ambulation model post-stroke was verified with adults aged 65+ and for those with OA. The models of community ambulation can be used to frame and conceptualize community ambulation research and clinical interventions.

Risk of waning humoral responses after inactivated or subunit recombinant SARS-CoV-2 vaccination in patients with chronic diseases: Findings from a prospective observational study in China.

Heterogeneity of antibody responses has been reported in SARS-CoV-2 vaccination recipients with underlying diseases. We investigated the impact of the presence of comorbidities on the humoral response to SARS-CoV-2 vaccination in patients with chronic disease (PWCD) and assessed the effect of the number of comorbidities on the humoral response to vaccination. In this study, neutralizing antibodies (NAbs) and IgG antibodies against the receptor-binding domain (RBD-IgG) were monitored following a full-course vaccination. In total, 1400 PWCD (82.7%, inactivated vaccines; 17.3%, subunit recombinant vaccine) and 245 healthy controls (65.7% inactivated vaccines, 34.3% subunit recombinant vaccine) vaccinated with inactivated or subunit recombinant SARS-CoV-2 vaccines, were included. The seroconversion and antibody levels of the NAbs and RBD-IgG were different in the PWCD group compared with those in the control group. Chronic hepatitis B (odds ratio [OR]: 0.65; 95% confidence interval [CI]: 0.46-0.93), cancer (OR: 0.65; 95% CI: 0.42-0.99), and diabetes (OR: 0.50; 95% CI: 0.28-0.89) were associated with lower seroconversion of NAbs. Chronic kidney disease (OR: 0.29; 95% CI: 0.11-0.76), cancer (OR: 0.38; 95% CI: 0.23-0.62), and diabetes (OR: 0.37; 95% CI: 0.20-0.69) were associated with lower seroconversion of RBD-IgG. Only the presence of autoimmune disease showed significantly lower NAbs and RBD-IgG titers. Patients with most types of chronic diseases showed similar responses to the controls, but humoral responses were still significantly associated with the presence of ≥2 coexisting diseases. Our study suggested that humoral responses following SARS-CoV-2 vaccination are impaired in patients with certain chronic diseases.

Impact of sarcosine on diabetic retinopathy: Findings based on weighted gene co-expression network analysis and machine learning techniques.

AIM: To quantify the association between serum sarcosine and diabetic retinopathy (DR) using weighted gene co-expression network analysis (WGCNA). METHODS: We measured serum metabolites in 69 pairs of type 2 diabetes (T2D) patients with and without DR matched by age, gender, body mass index（BMI and HbA1c, using a propensity score matching-based approach. To identify modules and metabolites linked to DR, pathway analysis was performed using WGCNA, the Kyoto Encyclopedia of Genes and Genomes and Small-Molecule Pathway Database. The association of sarcosine with DR was estimated by restricted cubic spline and conditional logistic regression models. Its joint effects with covariates on DR were also extensively examined. RESULTS: With per interquartile range elevation of sarcosine, the adjusted odds ratio (AOR) of DR significantly decreased by 67% (AOR: 0.33, 95% confidence interval [CI]: 0.19-0.58). Similar results were also found in the tertile analysis. Compared with those in the first tertile of sarcosine, the AOR significantly decreased by 54% (AOR: 0.46, 95% CI: 0.18-1.17) and 78% (AOR: 0.22, 95% CI: 0.08-0.59) for subjects in the second and third tertiles, respectively. Compared with subjects with lower sarcosine and lower HDL-C levels, those with higher sarcosine and lower HDL-C levels had the lowest odds of DR (OR: 0.13, 95% CI: 0.04, 0.43). CONCLUSIONS: Serum sarcosine was inversely related to DR, especially in T2D patients with insufficient HDL-C. This study provides insights on a possible novel target for DR precision prevention and control, as well as a better understanding of the DR mechanism.

The safety and immunogenicity of inactivated COVID-19 vaccine in old pulmonary tuberculosis patients.

The immunogenicity and safety of vaccines against coronavirus disease 2019 (COVID-19) remain unknown in patients with a history of pulmonary tuberculosis (OPTB). Therefore, the safety and effectiveness of inactivated vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) were assessed in patients with a history of PTB. The study cohort included 106 healthy controls and 93 adult patients with OPTB who received a two-dose vaccination. The study period was 21 to 105 days. Concentrations of antibodies (Abs) against receptor-binding domain (RBD) IgG and SARS-CoV-2 neutralizing Abs (NAbs) were measured, in addition to the frequencies of SARS-CoV-2-specific B and a portion T cells. The incidence of adverse events was similar between the OPTB patients and healthy controls. No severe adverse events occurred. Concentrations of Abs against RBD-IgG and CoV-2 neutralizing Abs in addition to the frequencies of RBD-specific memory B cells proportions were lower in OPTB patients than the healthy controls (all, p < 0.05), while the frequencies of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4+) cells were higher (p = 0.023). There was no obvious correlation between age and blood concentrations of Abs against RBD-IgG and CoV-2 neutralizing Abs, while immune responses were similar in the fibrosis and calcification groups. The period of time following full-course vaccination and lymphocyte counts were associated to anti-RBD-IgG responses. Inactivated COVID-19 vaccinations were well tolerated in OPTB patients, although immunogenicity was limited in this population. This study has been registered at ClinicalTrials.gov (NCT05043246).

Electrochemiluminescence imaging of a membrane carcinoembryonic antigen at single tissue sections.

Histopathological molecular testing of tissue sections is an essential step in tumor diagnosis; however, the commonly used immunohistochemical methods have problems such as low specificity and the subjective bias of the observer. Here, we report an electrochemiluminescence (ECL) imaging method to detect a membrane carcinoembryonic antigen (CEA) at the single tissue sections of cancer patients. By permeabilizing the tissue attached to a glassy carbon electrode, Ru(bpy)32+ tagged at the membrane CEA of the tissue could electrochemically react with TPrA in solution to emit ECL that has near-zero background and an extremely high signal-to-background ratio. Using the established ECL method, the expression differences and distribution characteristics of the CEA protein in the carcinoma and paracancerous tissues of pancreatic ductal carcinoma (PDAC) and lung adenocarcinoma (LUAD) patients are investigated. The images reveal that CEA proteins are mostly distributed in the acini and surrounding areas both in PDAC and LUAD tissues. Therefore, the presented approach could be able to provide a new molecular recognition method for the diagnosis of adenocarcinoma and other tumors.

Immune responses to inactivated COVID-19 vaccine were decreased in Chinese patients with chronic respiratory diseases.

Purpose: The effectiveness of inactivated vaccines against acute respiratory syndrome coronavirus 2 (SARS­CoV­2), the causative agent of coronavirus disease 2019 (COVID-19), has become a global concern. Hence, the aim of this study was to evaluate vaccine safety and to assess immune responses in individuals with chronic respiratory disease (CRD) following a two-dose vaccination. Methods: The study cohort included 191 participants (112 adult CRD patients and 79 healthy controls [HCs]) at least 21 (range, 21-159) days after a second vaccination. Frequencies of memory B cells (MBCs) subsets and titers of SARS-CoV-2 neutralizing antibodies (NAbs) and anti-receptor binding domain (RBD) IgG antibodies (Abs) were analyzed. Results: As compared to the HCs, CRD patients had lower seropositivity rates and titers of both anti-RBD IgG Abs and NAbs, in addition to lower frequencies of RBD-specific MBCs (all, p < 0.05). At 3 months, CRD patients had lower seropositivity rates and titers of anti-RBD IgG Abs than the HCs (p < 0.05). For CoronaVac, the seropositivity rates of both Abs were lower in patients with old pulmonary tuberculosis than HCs. For BBIBP-CorV, the seropositivity rates of CoV-2 NAbs were lower in patients with chronic obstructive pulmonary disease than HCs (all, p < 0.05). Meanwhile, there was no significant difference in overall adverse events between the CRD patients and HCs. Univariate and multivariate analyses identified the time interval following a second vaccination as a risk factor for the production of anti-RBD IgG Abs and CoV-2 NAbs, while the CoronaVac had a positive effect on the titers of both Abs. Female was identified as a protective factor for CoV-2 NAb levels. Conclusion: Inactivated COVID-19 vaccines were safe and well tolerated by CRD patients but resulted in lower Ab responses and the frequencies of RBD-specific MBCs. Therefore, CRD patients should be prioritized for booster vaccinations.

Verification of a comprehensive framework for mobility using data from the Canadian Longitudinal Study on Aging: a structural equation modeling analysis.

BACKGROUND: Mobility within and between life spaces is fundamental for health and well-being. Our objective was to verify a comprehensive framework for mobility. METHODS: This was a cross-sectional study. We used structural equation modeling to estimate associations between latent factors with data from the Canadian Longitudinal Study on Aging for participants 65-85 years of age (65+, n = 11,667) and for adults with osteoarthritis (OA) aged 45-85 (n = 5,560). Latent factors included life space mobility, and physical, psychosocial, environmental, financial, and cognitive elements. Personal variables (age, sex, education) were covariates. RESULTS: The models demonstrated good fit (65+: CFI = 0.90, RMSEA (90% CI) = 0.025 (0.024, 0.026); OA: CFI = 0.90, RMSEA (90% CI) = 0.032 (0.031, 0.033)). In both models, better psychosocial and physical health, and being less afraid to walk after dark (observed environmental variable) were associated with greater life space mobility. Greater financial status was associated with better psychosocial and physical health. Higher education was related to better cognition and finances. Older age was associated with lower financial status, cognition, and physical health. Cognitive health was positively associated with greater mobility only in the 65 + model. Models generated were equivalent for males and females. CONCLUSIONS: Associations between determinants described in the mobility framework were verified with adults 65-85 years of age and in an OA group when all factors were considered together using SEM. These results have implications for clinicians and researchers in terms of important outcomes when assessing life space mobility; findings support interdisciplinary analyses that include evaluation of cognition, depression, anxiety, environmental factors, and community engagement, as well as physical and financial health. Public policies that influence older adults and their abilities to access communities beyond their homes need to reflect the complexity of factors that influence life space mobility at both individual and societal levels.

Nanokit coupled electrospray ionization mass spectrometry for analysis of angiotensin converting enzyme 2 activity in single living cell.

Angiotensin-converting enzyme 2 (ACE2) is not only an enzyme but also a functional receptor on cell membrane for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, the activity of ACE2 in single living cell is firstly determined using a nanokit coupled electrospray ionization mass spectrometry (nanokit-ESI-MS). Upon the insertion of a micro-capillary into the living hACE2-CHO cell and the electrochemical sorting of the cytosol, the target ACE2 enzyme hydrolyses angiotensin II inside the capillary to generate angiotensin 1-7. After the electrospray of the mixture at the tip of the capillary, the product is differentiated from the substrate in molecular weight to achieve the detection of ACE2 activity in single cells. The further measurement illustrates that the inflammatory state of cells does not lead to the significant change of ACE2 catalytic activity, which elucidates the relationship between intracellular ACE2 activity and inflammation at single cell level. The established strategy will provide a specific analytical method for further studying the role of ACE2 in the process of virus infection, and extend the application of nanokit based single cell analysis.

Analysis of the uptake and associated factors for virtual crisis care during the pandemic at a 24-h mental health crisis centre in Manitoba, Canada.

BACKGROUND: The coronavirus pandemic necessitated the rapid transition to virtual care. At a 24-h walk-in mental health Crisis Response Centre (CRC) in Winnipeg, Canada we adapted crisis mental health assessments to be offered virtually while the crisis centre also remained open to in person visits. Little is known about the sustainability of virtual visits in the presence of comparable in person care, and which visits are more likely to be done virtually, particularly in the crisis setting. METHODS: An analysis of visits to the CRC from the first local lockdown on March 19, 2020 through the third local wave with heightened public health restrictions in June 2021. Analysis of Variance was used to compare the proportion of visits occurring virtually (telephone or videoconference) during the first wave of heightened public health restrictions (lockdown 1) and subsequent lockdowns as well as the in-between periods. A binary logistic regression examined visit, sociodemographic and clinical factors associated with receipt of a virtual visit compared to an in person visit over the first year of the pandemic. RESULTS: Out of 5,357 visits, 993 (18.5%) occurred virtually. There was a significant difference in proportion of virtual visits across the pandemic time periods (F(4, 62) = 8.56, p < .001). The proportion of visits occurring virtually was highest during lockdown 1 (mean 32.6% by week), with no differences between the other time periods. Receipt of a virtual visit was significantly associated with daytime weekday visits, age, non-male gender, living further away from the CRC, no prior year contact with the CRC, and visits that did not feature suicidal behaviour, substance use, psychosis or cognitive impairment. CONCLUSIONS: A large proportion of virtual care occurring at the outset of the pandemic reflects public anxiety and care avoidance paired with health system rapid transformation. The use of virtual visits reduced over subsequent pandemic periods but was sustained at a meaningful level. Specific visit, sociodemographic and clinical characteristics are more likely to be present in visits occurring virtually compared to those in person. These results can help to inform the future planning and delivery of virtual crisis care.

Control charts for chronic disease surveillance: testing algorithm sensitivity to changes in data coding.

BACKGROUND: Algorithms used to identify disease cases in administrative health data may be sensitive to changes in the data over time. Control charts can be used to assess how variations in administrative health data impact the stability of estimated trends in incidence and prevalence for administrative data algorithms. We compared the stability of incidence and prevalence trends for multiple juvenile diabetes algorithms using observed-expected control charts. METHODS: Eighteen validated algorithms for juvenile diabetes were applied to administrative health data from Manitoba, Canada between 1975 and 2018. Trends in disease incidence and prevalence for each algorithm were modelled using negative binomial regression and generalized estimating equations; model-predicted case counts were plotted against observed counts. Control limits were set as predicted case count ±0.8*standard deviation. Differences in the frequency of out-of-control observations for each algorithm were assessed using McNemar's test with Holm-Bonferroni adjustment. RESULTS: The proportion of out-of-control observations for incidence and prevalence ranged from 0.57 to 0.76 and 0.45 to 0.83, respectively. McNemar's test revealed no difference in the frequency of out-of-control observations across algorithms. A sensitivity analysis with relaxed control limits (2*standard deviation) detected fewer out-of-control years (incidence 0.19 to 0.33; prevalence 0.07 to 0.52), but differences in stability across some algorithms for prevalence. CONCLUSIONS: Our study using control charts to compare stability of trends in incidence and prevalence for juvenile diabetes algorithms found no differences for disease incidence. Differences were observed between select algorithms for disease prevalence when using wider control limits.

Nanopipettes for the Electrochemical Study of Enhanced Enzymatic Activity in a Femtoliter Space.

The chemical reaction in a confined space is known to be accelerated due to a high collision probability; however, the study of this confinement effect in a supersmall space down to femtoliter (fL) is seldom reported. Here, an adjustable volume [from picoliter (pL) to fL] of the aqueous phase is retrained at the tip of a nanopipette by an organic solvent so that the confinement effect on the specific activity of glucose oxidase is investigated. The activity is determined by the amount of hydrogen peroxide generated from the reaction between the oxidase and glucose using a nanoelectrode inside the nanopipette. As compared with the activity in bulk solution (82 U/mg), the activity increases up to 7500 U/mg in a 105 fL space. The 2 orders of magnitude increase in the enzymatic activity is the highest amplification in the volume-confined enzyme reaction as reported. A near-exponential drop in the activity is observed with the increase in the space volume, revealing the dominant enhancement in the confined space at the fL level for the first time. The established electrochemical nanopipettes should not only provide a strategy for the study of the enzymatic activity in supersmall confined space but also help understand the confinement effect of enzyme-catalyzed reactions.

A population-based study to develop juvenile arthritis case definitions for administrative health data using model-based dynamic classification.

BACKGROUND: Previous research has shown that chronic disease case definitions constructed using population-based administrative health data may have low accuracy for ascertaining cases of episodic diseases such as rheumatoid arthritis, which are characterized by periods of good health followed by periods of illness. No studies have considered a dynamic approach that uses statistical (i.e., probability) models for repeated measures data to classify individuals into disease, non-disease, and indeterminate categories as an alternative to deterministic (i.e., non-probability) methods that use summary data for case ascertainment. The research objectives were to validate a model-based dynamic classification approach for ascertaining cases of juvenile arthritis (JA) from administrative data, and compare its performance with a deterministic approach for case ascertainment. METHODS: The study cohort was comprised of JA cases and non-JA controls 16 years or younger identified from a pediatric clinical registry in the Canadian province of Manitoba and born between 1980 and 2002. Registry data were linked to hospital records and physician billing claims up to 2018. Longitudinal discriminant analysis (LoDA) models and dynamic classification were applied to annual healthcare utilization measures. The deterministic case definition was based on JA diagnoses in healthcare use data anytime between birth and age 16 years; it required one hospitalization ever or two physician visits. Case definitions based on model-based dynamic classification and deterministic approaches were assessed on sensitivity, specificity, and positive and negative predictive values (PPV, NPV). Mean time to classification was also measured for the former. RESULTS: The cohort included 797 individuals; 386 (48.4 %) were JA cases. A model-based dynamic classification approach using an annual measure of any JA-related healthcare contact had sensitivity = 0.70 and PPV = 0.82. Mean classification time was 9.21 years. The deterministic case definition had sensitivity = 0.91 and PPV = 0.92. CONCLUSIONS: A model-based dynamic classification approach had lower accuracy for ascertaining JA cases than a deterministic approach. However, the dynamic approach required a shorter duration of time to produce a case definition with acceptable PPV. The choice of methods to construct case definitions and their performance may depend on the characteristics of the chronic disease under investigation.

Positive results for patients with COVID-19 discharged form hospital in Chongqing, China.

BACKGROUND: Since December 2019, over 80,000 patients with coronavirus disease 2019 (COVID-19) have been confirmed in China. With the increasing number of recovered patients, more attention should be paid to the follow-up of these patients. METHODS: In the study, 576 patients with COVID-19 discharged from hospital in Chongqing, China from January 24, 2020, to March 10, 2020 were evaluated by viral nucleic acid tests for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) to determine if they could be released from quarantine. Among the 576 patients, 61 patients (10.6%) had positive RT-PCR test results of SARS-CoV-2. We aimed to analyze the demographics, clinical characteristics and treatment of 61 patients. RESULTS: These positive patients were characterized by older age, chronic medical illness and mild conditions. 38 (62.3%) patients who were asymptomatic without abnormalities on chest radiographs were found in the positive with COVID-19. Also, they showed positive results of stool or sputum specimens with negative results of nasal and pharyngeal swab specimens. The median duration of positive result of SARS-CoV-2 was varied from 3 days to 35 days in the patients discharged from hospital with no family member infection. CONCLUSIONS: Multi-site screening of SARS-CoV-2 including nasal and pharyngeal swabs, stool and sputum specimens could be considered to improve the diagnosis, treatment and infection control in patients with COVID-19. Our findings provide the important information and clinical evidence for the improved management of patients recovered from COVID-19.

Plasma YKL-40 and NGAL are useful in distinguishing ACO from asthma and COPD.

BACKGROUND: Asthma-chronic obstructive pulmonary disorder (COPD) overlap (ACO) is characterized by the coexistence of features of both asthma and COPD and is associated with rapid progress and a poor prognosis. Thus, the early recognition of ACO is crucial. OBJECTIVES: We sought to explore the plasma levels of biomarkers associated with asthma (periostin, TSLP and YKL-40), COPD (NGAL) and their possible correlation with lung function, the bronchodilator response and radiographic imaging in patients with asthma, COPD and with features of ACO. METHODS: We enrolled 423 subjects from 6 clinical centers. All participants underwent blood collection, lung function measurements, bronchodilator response tests and high-resolution CT. Correlations of the plasma biomarkers with lung function, the bronchodilator response and percentemphysema were calculated by Spearman's rank correlation and multivariate stepwise regressionanalysis. RESULTS: 1) Patients with features of ACO had lower plasma YKL-40 than COPD patients and a moderate elevated plasma level of NGAL compared with asthma patients. 2) Patients with features of ACO had an intermediate degree of airflow obstruction, the bronchodilator response and emphysema between patients with COPD and asthma. 3) Plasma YKL-40 was negatively correlated with lung function and with the bronchodilator response, and plasma NGAL was positively correlated with the extent of emphysema. CONCLUSIONS: Plasma YKL-40 is a promising candidate for distinguishing between patients with features of ACO and COPD patients, while plasma NGAL may be a valuable biomarker for differentiating between patients with features of ACO and asthma patients. CLINICAL TRIAL REGISTRATION: ChiCTR-OOC-16009221.

Gold-coated polydimethylsiloxane microwells for high-throughput electrochemiluminescence analysis of intracellular glucose at single cells.

In this communication, a gold-coated polydimethylsiloxane (PDMS) chip with cell-sized microwells was prepared through a stamping and spraying process that was applied directly for high-throughput electrochemiluminescence (ECL) analysis of intracellular glucose at single cells. As compared with the previous multiple-step fabrication of photoresist-based microwells on the electrode, the preparation process is simple and offers fresh electrode surface for higher luminescence intensity. More luminescence intensity was recorded from cell-retained microwells than that at the planar region among the microwells that was correlated with the content of intracellular glucose. The successful monitoring of intracellular glucose at single cells using this PDMS chip will provide an alternative strategy for high-throughput single-cell analysis. Graphical abstract ᅟ.

Caffeine is a risk factor for osteopenia of prematurity in preterm infants: a cohort study.

BACKGROUND: Caffeine, the most commonly used medication in Neonatal Intensive Care Units, has calciuric and osteoclastogenic effects. METHODS: To examine the association between the cumulative dose and duration of therapy of caffeine and osteopenia of prematurity, a retrospective cohort study was conducted including premature infants less than 31 weeks and birth weight less than 1500 g. Osteopenia of prematurity was evaluated using chest X-rays on a biweekly basis over 12 weeks of hospitalization. RESULTS: The cohort included 109 infants. 51% had osteopenia of prematurity and 8% had spontaneous rib fractures. Using the generalized linear mixed model, caffeine dose and duration of caffeine therapy showed a strong association with osteopenia of prematurity. Steroids and vitamin D were also significantly correlated with osteopenia of prematurity while diuretic use did not show a statistically significant effect. CONCLUSION: The cumulative dose and duration of therapy of caffeine, as well as steroid are associated with osteopenia of prematurity in this cohort. Future studies are needed to confirm these findings and determine the lowest dose of caffeine needed to treat effectively apnea of prematurity.

A Comparison of Variable- and Person-Oriented Approaches in Evaluating a Universal Preventive Intervention.

Evaluations of prevention programs, such as the PAX Good Behavior Game (PAX), often have multiple outcome variables (e.g., emotional, behavioral, and relationship problems). These are often reported for multiple time points (e.g., pre- and post-intervention) where data are multilevel (e.g., students nested in schools). In this paper, we present both variable-oriented and person-oriented statistical approaches, to evaluate an intervention program with multilevel, longitudinal multivariate outcomes. Using data from the Manitoba PAX Study, we show how these two approaches provide us with different information that can be complementary. Data analyses with the variable-oriented approach (multilevel linear regression model) provided us with overall PAX program effects for each outcome variable; the person-oriented approach (latent transition analysis) allowed us to explore the transition of multiple outcomes across multiple time points and how the intervention program affects this transition differently for students with different risk profiles. We also used both approaches to examine how gender and socio-economic status related to the program effects. The implications of these results and the use of both types of approaches for program evaluation are discussed.

C3N4 Nanosheet Modified Microwell Array with Enhanced Electrochemiluminescence for Total Analysis of Cholesterol at Single Cells.

Here, a g-C3N4 nanosheet modified microwell array providing enhanced electrochemiluminescence (ECL) and better visible sensitivity was prepared to simultaneously analyze total (membrane and intracellular) cholesterol at single cells. The detection limit for ECL visualization of hydrogen peroxide at microwell array was improved to be 500 nM that guaranteed the detection of low concentration cholesterol at single cells in parallel. To achieve single cell cholesterol analysis, the individual cells cultured at the microwell array were exposed to cholesterol oxidase generating hydrogen peroxide for luminescence analysis of membrane cholesterol, and then treated with triton X-100, cholesterol esterase, and cholesterol oxidase to produce hydrogen peroxide from intracellular cholesterol for luminescence determination. The observation of the luminescence spots at microwells in these two steps confirmed the codetection of membrane and intracellular cholesterol at single cells. The inhibition of intracellular acyl-coA/cholesterol acyltransferase (ACAT) resulted in less intracellular cholesterol storage (less luminescence) and more membrane cholesterol (more luminescence). The correlation of the luminescence intensity with the amount of cholesterol confirmed that our assay could simultaneously monitor membrane and intracellular cholesterol pools at different cellular states, which should offer more information for the study of cholesterol-related pathways at single cells.

Mechanisms that determine nanocarrier targeting to healthy versus inflamed lung regions.

Inflamed organs display marked spatial heterogeneity of inflammation, with patches of inflamed tissue adjacent to healthy tissue. To investigate how nanocarriers (NCs) distribute between such patches, we created a mouse model that recapitulates the spatial heterogeneity of the inflammatory lung disease ARDS. NCs targeting the epitope PECAM strongly accumulated in the lungs, but were shunted away from inflamed lung regions due to hypoxic vasoconstriction (HVC). In contrast, ICAM-targeted NCs, which had lower whole-lung uptake than PECAM/NCs in inflamed lungs, displayed markedly higher NC levels in inflamed regions than PECAM/NCs, due to increased regional ICAM. Regional HVC, epitope expression, and capillary leak were sufficient to predict intra-organ of distribution of NCs, antibodies, and drugs. Importantly, these effects were not observable with traditional spatially-uniform models of ARDS, nor when examining only whole-organ uptake. This study underscores how examining NCs' intra-organ distribution in spatially heterogeneous animal models can guide rational NC design.