23 Using visual data and teleophthalmology in paediatric ophthalmology with an app-free, browser-based, visual data platform: ISLACARE

Visual data is underutilised in ophthalmology particularly within paediatrics. Following the pandemic, virtual and remote clinics in the form of telephone and video consultations have increased but there are limitations within paediatric ophthalmology as synchronous telephone or video calls are time-consuming.Using a platform known as ISLACARE, we are able to run remote photo and video clinics that has the capability to support asynchronous or synchronous consultations. With this software, parents and clinicians do not need to create logins or download apps thus increasing compliance with the technology.In an audit of 101 consecutive cases, the following was found. Mean age: 6.67 years (0-17years). The top 4 categories used in were anterior segment (36%), Strabismus (24%), Orbit/Trauma (17%), and Oculoplastics (12%).On the use of photographs to support consultations , it was felt that 91% reduced time to treatment/supported clinical decision making and 75% improved clinician to clinician communication. We have found a 30% increase in capacity in our remote teleophthalmology clinics by utilising a pre-consultation proforma. A particular improvement has been in post-operative strabismus cases where 90% of all our first appointment checks are now done remotely.We would like to demonstrate the clinical flow of how we use ISLACARE for asynchronous consultations, remote monitoring, and visual data archiving.

Choroid Plexus Calcification Correlates with Cortical Microglial Activation in Humans: A Multimodal PET, CT, MRI Study

BACKGROUND AND PURPOSE

The choroid plexus (CP) within the brain ventricles is well-known to produce cerebrospinal fluid (CSF). Recently, the CP has been recognized as critical in modulating inflammation. MRI-measured CP enlargement has been reported in neuroinflammatory disorders like MS as well as with aging and neurodegeneration. The basis of MRI-measured CP enlargement is unknown. On the basis of tissue studies demonstrating CP calcification as a common pathology associated with aging and disease, we hypothesized that previously unmeasured CP calcification contributes to MRI-measured CP volume and may be more specifically associated with neuroinflammation.

MATERIALS AND METHODS

We analyzed 60 subjects (43 healthy controls and 17 subjects with Parkinson's disease) who underwent PET/CT using 11C-PK11195, a radiotracer sensitive to the translocator protein expressed by activated microglia. Cortical inflammation was quantified as nondisplaceable binding potential. Choroid plexus calcium was measured via manual tracing on low-dose CT acquired with PET and automatically using a new CT/MRI method. Linear regression assessed the contribution of choroid plexus calcium, age, diagnosis, sex, overall volume of the choroid plexus, and ventricle volume to cortical inflammation.

RESULTS

Fully automated choroid plexus calcium quantification was accurate (intraclass correlation coefficient with manual tracing = .98). Subject age and choroid plexus calcium were the only significant predictors of neuroinflammation.

CONCLUSIONS

Choroid plexus calcification can be accurately and automatically quantified using low-dose CT and MRI. Choroid plexus calcification-but not choroid plexus volume-predicted cortical inflammation. Previously unmeasured choroid plexus calcium may explain recent reports of choroid plexus enlargement in human inflammatory and other diseases. Choroid plexus calcification may be a specific and relatively easily acquired biomarker for neuroinflammation and choroid plexus pathology in humans.

Advanced Catalytic Technologies for Compressed Natural Gas – Gasoline Fuelled Engines

The main challenges of the CNG engine fuelling in terms of methane abatement in the aftertreatment system are addressed in this study by using different loaded PGM catalysts. A dual-fuel injection strategy of methane-gasoline was implemented where methane gas was port-injected into the intake in stoichiometric conditions at levels corresponding to 20 and 40% energy density replacement of gasoline fuel. High, medium, and low loaded Pd/Rh catalysts were used and compared to study the effect of PGM loading on the catalyst light-off activity for methane. Results indicate that increasing the Pd loading led to significantly earlier light-off temperatures achieved at relatively lower temperatures of 340, 350 and 395oC respectively. However, the benefit diminishes above Pd loading >142.5 g ft-3. The study has also demonstrated that NH3 is formed over the CNG catalyst due to steam-reforming reactions from the increased levels of methane in the exhaust with the dual-fuelling. Hence aftertreatment technologies such as SCR should be adopted to remove them. This further highlights the need to regulate the harmful NH3 emissions from future passenger cars fuelled with CNG. In addition, the benefits of the dual-fuel system in terms of lower engine output CO2, non-methane hydrocarbon (NMHC) and particulate matter (PM) emissions compared to the GDI mode alone are presented.

LSPR based on-chip detection of dengue NS1 antigen in whole blood

The development of a biosensor for rapid and quantitative detection of the dengue virus continues to remain a challenge. We report a lab-on-chip device that combines membrane-based blood plasma separation and a localized surface plasmon resonance (LSPR) based biosensor for on-chip detection of dengue NS1 antigen from a few drops of blood. The LSPR effect is realized by irradiating UV-NIR light having a spectral peak at 655 nm onto nanostructures fabricated via thermal annealing of a thin metal film. We study the effect of the resulting metal nanostructures on the LSPR performance in terms of sensitivity and limit of detection, by annealing silver films at temperatures ranging from 100 to 500 °C. The effect of annealing temperature on the nanostructure size and uniformity and the resulting optical characteristics are investigated. Further, the binding between non-targeted blood plasma proteins and NS1-antibody-functionalized nanostructures on the LSPR performance is studied by considering different blocking mechanisms. Using a nanostructure annealed at 200 °C and 2X-phosphate buffer saline with 0.05% Tween-20 as the blocking buffer, from 10 μL of whole blood, the device can detect NS1 antigen at a concentration as low as 0.047 μg mL-1 within 30 min. Finally, we demonstrate the detection of NS1 in the blood samples of dengue-infected patients and validate our results with those obtained from the gold-standard ELISA test.

1214 Higher Bedroom Temperature Associated With Poorer Sleep: Data From Over 3.75 Million Nights

Introduction

Bedroom temperature can influence nocturnal thermoregulation and sleep. To date, limited, small experimental studies have shown that bedroom temperatures outside the recommended range of 65 and 70°F can negatively impact sleep. However, this association has not been studied in a large-scale data set. Using over 3.75 million nights of objectively measured data, we analyzed the associations between habitual bedroom temperatures and sleep.

Methods

Over 3.75 million nights of sleep and bedroom temperature data were collected using S+ by ResMed technology from 34,096 Individuals (57% male, 20-90 years, mean age 48.7 +/-14.5 years, all US residents). Multilevel regression analyses were used to analyze associations between bedroom temperature and sleep. A stricter alpha level of 0.001 was used to account for the large number of observations in the dataset.

Results

Bedroom temperature was above 70°F for 69% of nights, with the average temperature ranging between 68.8 and 76.2°F. For each 1°F increase in bedroom temperature between 60-85°F, sleep efficiency decreased by 0.06%. Likewise, higher bedroom temperatures were linked to shorter Total Sleep Time duration (-0.45 mins/°F), longer Sleep Onset Latency (+0.04 mins/°F), and longer Wake After Sleep Onset (+0.11 mins/°F), all ps<0.001.

Conclusion

Analyzing data from over 3.75 million nights, we found that many people sleep in a bedroom warmer than the optimal temperature. Further, higher bedroom temperatures - even within the recommended range for optimal sleep - are associated with poorer sleep and higher wakefulness. Bedroom thermostats and cooling options should be considered to achieve optimal sleeping temperature conditions.

Support

N/A

0412 Parents Sleep Longer When School is Out for the Summer: Associations Among Parenthood, Gender, and Season

Introduction

Seasonal effects in sleep are often attributed to day length; however, change in obligatory daily activities might also have an impact on sleep behavior. Longitudinal measurement using consumer sleep technology enables the observation of patterns in sleep behavior in the home environment. We analyzed the impact of parenthood and gender on total sleep time (TST) over the summer break period using data collected in the home.

Methods

Sleep data were collected using the SleepScore mobile application from October 2018 through October 2019, with the summer break period defined as June 25th - August 5th. U.S. age and gender matched samples of parents and non-parents were selected using Mahalanobis distance from a pool of users more likely to have school-aged children. The final samples included n=345 parents (38.7 +/- 4.5 years) and n=345 non-parents (37.8 +/- 4.7 years); both groups were 46% female. Only weeknights (n=34,323) were analyzed to maximize impact of school schedule. Linear regression and independent t-tests were used to analyze main and interaction effects for gender, parenthood, and summer break.

Results

Male gender, parenthood, and summer break were associated with decreased sleep duration (ps < .01). However, during summer break, parents exhibited an increase in TST, with mothers (+5.6 mins) having a greater increase than fathers (+1.1 mins). In contrast, adults without children showed a decrease in TST during summer break, with males having a greater reduction (-8.8 mins) than females (-6.5 mins).

Conclusion

These results suggest that parental status may play a part in seasonal sleep patterns. Contrary to the typical trend of shorter TST during summer, being a parent is associated with longer TST during summer break, with a greater increase for females. This change may be attributed to parents following a less rigid schedule when their children are not in school.

Support

N/A

0443 Intra Week Sleep Patterns Analyzed Using Consumer Sleep Tracker Data

Introduction

Big data collected using consumer sleep technology can provide objectively measured insights on sleep behavior in the real-life environment. It has the advantage over self-report data of being less prone to bias. Here we used a non-contact bio-motion sensor to remotely capture objective sleep data. We analyzed 168432 nights of sleep data to test if differences between weekday versus weekend sleep behavior, known from self-report, would still hold using objective data in a large population.

Methods

Sleep data was acquired using the SleepScore Max remote sleep sensor and included 168432 nights (2730 users, mean age: 46.6 +/- 11.8 years, 33% female, all resident in the USA). Analysis was restricted to those of working age; adults between 20-65. Any sleep which ended from Monday to Friday was considered weekday sleep, and any ending on Saturday or Sunday as weekend sleep. Data records were inspected and cleaned before analyzing. Descriptive statistics and independent t-tests were used to analyze the data.

Results

Total Sleep Time, Time In Bed and Sleep Onset Latencies were longer during weekend (TST: + 20.6 mins, TIB: +22.9 mins, SOL: +1.1 min, all p <0.001), resulting in a slightly poorer Sleep Efficiency (-.016%, p<0.01) for weekend nights. Time to bed and final awakening were both delayed in weekends as compared to weekdays (Time to bed +30.0 mins, and final awakening +53.4 mins, both p<0.001).

Conclusion

This big data analysis confirms the earlier observed difference in sleep and sleep behavior between weekdays and weekends. This should be considered for optimizing (automated) sleep interventions, that may not normally take the weekend effect into consideration.

Support

 

Outcome of pregnancies in women with pulmonary hypertension: a single-centre experience from South India

OBJECTIVE

To study maternal complications and pregnancy outcome in women with pulmonary hypertension, attending a tertiary centre in south India.

STUDY DESIGN

Retrospective observational study.

SETTING

Tertiary centre in south India.

POPULATION

Pregnant women with pulmonary hypertension.

METHOD

Data regarding demographics, clinical course, medication received, and echocardiographic diagnosis regarding pulmonary hypertension and antenatal care received were collected from the records. Details of labour and delivery, and postpartum follow up were retrieved. We compared the outcome based on the presence or absence of cyanosis and right ventricular systolic pressure levels.

MAIN OUTCOME MEASURES

Maternal mortality, occurrence of complications such as heart failure, fetal growth restriction.

RESULTS

There were 81 pregnancies in 73 women with pulmonary hypertension. The majority of them had pulmonary hypertension secondary to congenital heart disease (80.8%); 17.8% had Eisenmenger syndrome. An advanced pulmonary artery hypertension (PAH) medication, sildenafil, was administered in 25 (31.3%) pregnancies. There were four maternal deaths, of which three had Eisenmenger syndrome. Heart failure complicated 6.3% and fetal growth restriction 26.3% of pregnancies. Morbidity was significantly increased in women with pulmonary hypertension associated with a cyanotic cardiac lesion or with right ventricular systolic pressure >70 mmHg.

CONCLUSION

Despite advances in care, mortality in pregnant women with pulmonary hypertension is a matter of concern, especially in those with Eisenmenger syndrome. Multidisciplinary team management in tertiary centres and the use of advanced PAH medications even in low- to middle-income countries with limited resources, could lead to a reduction in morbidity and mortality related to pulmonary hypertension.

TWEETABLE ABSTRACT

Multidisciplinary care and use of new medication may improve outcomes in pregnant women with pulmonary hypertension.

Predictive model of spread of Parkinson's pathology using network diffusion

Growing evidence suggests that a "prion-like" mechanism underlies the pathogenesis of many neurodegenerative disorders, including Parkinson's disease (PD). We extend and tailor previously developed quantitative and predictive network diffusion model (NDM) to PD, by specifically modeling the trans-neuronal spread of alpha-synuclein outward from the substantia nigra (SN). The model demonstrated the spatial and temporal patterns of PD from neuropathological and neuroimaging studies and was statistically validated using MRI deformation of 232 Parkinson's patients. After repeated seeding simulations, the SN was found to be the most likely seed region, supporting its unique lynchpin role in Parkinson's pathology spread. Other alternative spread models were also evaluated for comparison, specifically, random spread and distance-based spread; the latter tests for Braak's original caudorostral transmission theory. We showed that the distance-based spread model is not as well supported as the connectivity-based model. Intriguingly, the temporal sequencing of affected regions predicted by the model was in close agreement with Braak stages III-VI, providing what we consider a "computational Braak" staging system. Finally, we investigated whether the regional expression patterns of implicated genes contribute to regional atrophy. Despite robust evidence for genetic factors in PD pathogenesis, NDM outperformed regional genetic expression predictors, suggesting that network processes are far stronger mediators of regional vulnerability than innate or cell-autonomous factors. This is the first finding yet of the ramification of prion-like pathology propagation in Parkinson's, as gleaned from in vivo human imaging data. The NDM is potentially a promising robust and clinically useful tool for diagnosis, prognosis and staging of PD.

Learning from UJAMBO: Perspectives on Gynecologic Care in African Immigrant and Refugee Women in Boston, Massachusetts

African-born immigrant women, and particularly refugees and asylum seekers, are at risk for reproductive health disparities but inadequately use relevant gynecologic services. We sought to elucidate perspectives on gynecologic care in a population of Congolese and Somali immigrants. We conducted a secondary qualitative analysis of focus group data using a grounded theory approach and the Integrated Behavioral Model as our theoretical framework. Thirty one women participated in six focus groups. Participant beliefs included the states of pregnancy and/or pain as triggers for care, preferences included having female providers and those with familiarity with female genital cutting. Barriers included stigma, lack of partner support, and lack of resources to access care. Experiential attitudes, normative beliefs, and environmental constraints significantly mediated care preferences for/barriers to gynecologic health service utilization in this population. Centering of patient perspectives to adapt delivery of gynecologic care to immigrants and refugees may improve utilization and reduce disparities.

Weak correlation of bleeding scores to platelet electron microscopy: A retrospective chart review of pediatric patients with delta-storage pool disorder

BACKGROUND

Delta granule storage pool deficiency (δ-SPD) is a rare platelet disorder in which a deficiency of platelet granules leads to poor aggregation, resulting in varying clinical bleeding phenotypes. Children with δ-SPD have variable laboratory results, making the proper diagnosis and evaluation controversial.

OBJECTIVES

To describe the demographic and laboratory trends of this population and to assess the value of electron microscopy in diagnostic evaluation and its correlation to bleeding symptoms.

METHODS

We performed a retrospective review of 109 pediatric patients diagnosed with δ-SPD. We collected demographic information and bleeding scores using a validated bleeding assessment tool. A descriptive and exploratory analysis was performed.

RESULTS

The majority of patients were female, with an average age at diagnosis of 11.61 years. Females were diagnosed at a significantly older age presenting most often with menorrhagia, while males presented most commonly with epistaxis. The majority showed normal lumiaggregometry, the mean platelet electron microscopy (PEM) value was 2.37, and the mean bleeding score was 6. Bleeding assessment tool and PEM had a significantly weak correlation.

CONCLUSIONS

Patients with more dense granules per platelet had higher bleeding scores than those with fewer dense granules per platelet. The current body of evidence does not favor the use of PEM in routine clinical practice, and results are difficult to interpret. In patients with severe mucocutaneous bleeding symptoms and normal platelet aggregation studies, consideration should be given to an alternative diagnosis and further evaluation is warranted.

Non-inertial lift induced migration for label-free sorting of cells in a co-flowing aqueous two-phase system

We present a novel label-free passive microfluidic technique for isolation of cancer cells (EpCAM+ and CD45−) from peripheral blood mononuclear cells (PBMCs) (CD45+ and EpCAM−) in aqueous two-phase system (ATPS).

Entry and passage behavior of biological cells in a constricted compliant microchannel

We report an experimental and theoretical investigation of the entry and passage behaviour of biological cells (HeLa and MDA-MB-231) in a constricted compliant microchannel. Entry of a cell into a micro-constriction takes place in three successive regimes: protrusion and contact (cell protrudes its leading edge and makes a contact with the channel wall), squeeze (cell deforms to enter into the constriction) and release (cell starts moving forward). While the protrusion and contact regime is insensitive to the flexibility of the channel, the squeeze zone is significantly smaller in the case of a more compliant channel. Similarly, in the release zone, the acceleration of the cells into the microconstriction is higher in the case of a more compliant channel. The results showed that for a fixed size ratio ρ and E c, the extension ratio λ decreases and transit velocity U c increases with increase in the compliance parameter f p. The variation in the cell velocity is governed by force due to the cell stiffness F s as well as that due to the viscous dampening F d, explained using the Kelvin-Voigt viscoelastic model. The entry time t e = m(ρ) k 1 (1 + f p) k 2 (E c) k 3 and induced hydrodynamic resistance of a cell ΔR c/R = k(ρ) a (1 + k f f p) b (k E E c) c were correlated with cell size ratio ρ, Young's modulus E c and compliance parameter f p, which showed that both entry time t e and the induced hydrodynamic resistance ΔR c are most sensitive to the change in the compliance parameter f p. This study provides understanding of the passage of cells in compliant micro-confinements that can have significant impact on mechanophenotyping of single cells.

A slow-cycling subpopulation of melanoma cells with highly invasive properties

Melanoma is a heterogeneous tumor with different subpopulations showing different proliferation rates. Slow-cycling cells were previously identified in melanoma, but not fully biologically characterized. Using the label-retention method, we identified a subpopulation of slow-cycling cells, defined as label-retaining cells (LRC), with strong invasive properties. We demonstrate through live imaging that LRC are leaving the primary tumor mass at a very early stage and disseminate to peripheral organs. Through global proteome analyses, we identified the secreted protein SerpinE2/protease nexin-1 as causative for the highly invasive potential of LRC in melanomas.

A combined experimental and theoretical approach towards mechanophenotyping of biological cells using a constricted microchannel

We report a combined experimental and theoretical technique that enables the characterization of various mechanical properties of biological cells. The cells were infused into a microfluidic device that comprises multiple parallel micro-constrictions to eliminate device clogging and facilitate characterization of cells of different sizes and types on a single device. The extension ratio λ and transit velocity U_c of the cells were measured using high-speed and high-resolution imaging which were then used in a theoretical model to predict the Young's modulus E_c = f(λ, U_c) of the cells. The predicted Young's modulus E_c values for three different cell lines (182 ± 34.74 Pa for MDA MB 231, 360 ± 75 Pa for MCF 10A and, 763 ± 93 Pa for HeLa) compare well with those reported in the literature from micropipette measurements and atomic force microscopy measurement within 10% and 15%, respectively. Also, the Young's modulus of MDA-MB-231 cells treated with 50 μM 4-hyrdroxyacetophenone (for localization of myosin II) for 30 min was found out to be 260 ± 52 Pa. The entry time t_e of cells into the micro-constrictions was predicted using the model and validated using experimentally measured data. The entry and transit behaviors of cells in the micro-constriction including cell deformation (extension ratio λ) and velocity U_c were experimentally measured and used to predict various cell properties such as the Young's modulus, cytoplasmic viscosity and induced hydrodynamic resistance of different types of cells. The proposed combined experimental and theoretical approach leads to a new paradigm for mechanophenotyping of biological cells.

Characterization and sorting of cells based on stiffness contrast in a microfluidic channel

This paper reports the characterization and sorting of cells based on stiffness contrast. A microfluidic device with focusing and spacing control for stiffness based sorting of cells is designed, fabricated and demonstrated.

Assessment of knowledge of medicinal plants and their use in tribal region of Jashpur district of Chhattisgarh, India

The present study was conducted to assess the knowledge of medicinal plants and their use in tribal region of Jashpur district of Chhattisgarh. Under the socio-economic profile, farmers of middle age (36-55 yrs) people showed the maximum percentage (78%) distribution and frequency, 50 per cent of respondents belonged to primary to middle school level of education and 63 per cent of respondents were having medium size of family (5 to 8 members). A total number of 50 medicinal plant species belonging to 29 families were recorded, in which Euphorbiaceae registered as the largest family with 4 plant species (8%). Shrub showed their maximum presence (34%) followed by tree (32%), herb (20%) and climber (14%). As per knowledge of respondents about medicinal plants Haldi and Bhui-neem is mostly use as medicinal purpose as 5.2% (n=40) followed by Harra, Munga, Karanj and Hadjod (3.9% each). This information through respondent (tribals) showed very diverse nature of medicinal flora, their usage in healing purpose with socioeconomic/ living standard upliftment. Therefore, it is needful aspect of conserving these biological resources for sustainable ecosystem.

Spectroscopic investigation (FT-IR, FT-Raman), HOMO-LUMO, NBO analysis and molecular docking study of 2-[(4-chlorobenzyl)sulfanyl]-4-(2-methylpropyl)-6-[3-trifluoromethyl)-anilino]pyrimidine-5-carbonitrile, a potential chemotherapeutic agent

FT-IR and FT-Raman spectra of 2-[(4-chlorobenzyl)sulfanyl]-4-(2-methylpropyl)-6-[3-trifluoromethyl)-anilino]pyrimidine-5-carbonitrile were recorded and analyzed. The vibrational wave numbers were computed using DFT quantum chemical calculations. The data obtained from wave number calculations are used to assign vibrational bands obtained in infrared and Raman spectra. Potential energy distribution was done using GAR2PED program. The NH stretching wave number is red shifted by 102 cm(-1) in IR from the computed wave number, which indicates the weakening of the NH bond. The geometrical parameters (DFT) of the title compound are in agreement with the XRD results. NBO analysis, HOMO-LUMO, first hyperpolarizability and molecular electrostatic potential results are also reported. From the MEP map it is evident that the negative electrostatic potential regions are mainly localized over the CN and CF3 groups and are possible sites for electrophilic attack and positive regions are localized around NH group, indicating possible sites for nucleophilic attack. The preliminary docking results suggest that the title compound might exhibit inhibitory activity against GPb and may act as a potential anti-diabetic compound.

Modeling the relationship among gray matter atrophy, abnormalities in connecting white matter, and cognitive performance in early multiple sclerosis

BACKGROUND AND PURPOSE

Quantitative assessment of clinical and pathologic consequences of white matter abnormalities in multiple sclerosis is critical in understanding the pathways of disease. This study aimed to test whether gray matter atrophy was related to abnormalities in connecting white matter and to identify patterns of imaging biomarker abnormalities that were related to patient processing speed.

MATERIALS AND METHODS

Image data and Symbol Digit Modalities Test scores were collected from a cohort of patients with early multiple sclerosis. The Network Modification Tool was used to estimate connectivity irregularities by projecting white matter abnormalities onto connecting gray matter regions. Partial least-squares regression quantified the relationship between imaging biomarkers and processing speed as measured by the Symbol Digit Modalities Test.

RESULTS

Atrophy in deep gray matter structures of the thalami and putamen had moderate and significant correlations with abnormalities in connecting white matter (r = 0.39-0.41, P < .05 corrected). The 2 models of processing speed, 1 for each of the WM imaging biomarkers, had goodness-of-fit (R(2)) values of 0.42 and 0.30. A measure of the impact of white matter lesions on the connectivity of occipital and parietal areas had significant nonzero regression coefficients.

CONCLUSIONS

We concluded that deep gray matter regions may be susceptible to inflammation and/or demyelination in white matter, possibly having a higher sensitivity to remote degeneration, and that lesions affecting visual processing pathways were related to processing speed. The Network Modification Tool may be used to quantify the impact of early white matter abnormalities on both connecting gray matter structures and processing speed.

Factors associated with study attrition among HIV-infected risky drinkers in St. Petersburg, Russia

BACKGROUND

Participant attrition in HIV longitudinal studies may introduce bias and diminish research quality. The identification of participant characteristics that are predictive of attrition might inform retention strategies.

OBJECTIVE

The study aimed to identify factors associated with attrition among HIV-infected Russian risky drinkers from the secondary HIV prevention HERMITAGE trial. We examined whether current injection drug use (IDU), binge drinking, depressive symptoms, HIV status nondisclosure, stigma, and lifetime history of incarceration were predictors of study attrition. We also explored effect modification due to gender.

METHODS

Complete loss to follow-up (LTFU), defined as no follow-up visits after baseline, was the primary outcome, and time to first missed visit was the secondary outcome. We used multiple logistic regression models for the primary analysis, and Cox proportional hazards models for the secondary analysis.

RESULTS

Of 660 participants, 101 (15.3%) did not return after baseline. No significant associations between independent variables and complete LTFU were observed. Current IDU and HIV status nondisclosure were significantly associated with time to first missed visit (adjusted hazard ratio [AHR], 1.39; 95% CI, 1.03-1.87; AHR, 1.38; 95% CI, 1.03-1.86, respectively). Gender stratified analyses suggested a larger impact of binge drinking among men and history of incarceration among women with time to first missed visit.

CONCLUSIONS

Although no factors were significantly associated with complete LTFU, current IDU and HIV status nondisclosure were significantly associated with time to first missed visit in HIV-infected Russian risky drinkers. An understanding of these predictors may inform retention efforts in longitudinal studies.

Reduced glucose uptake and Aβ in brain regions with hyperintensities in connected white matter

Interstitial concentration of amyloid beta (Aß) is positively related to synaptic activity in animal experiments. In humans, Aß deposition in Alzheimer's disease overlaps with cortical regions highly active earlier in life. White matter lesions (WML) disrupt connections between gray matter (GM) regions which in turn changes their activation patterns. Here, we tested if WML are related to Aß accumulation (measured with PiB-PET) and glucose uptake (measured with FDG-PET) in connected GM. WML masks from 72 cognitively normal (age 61.7 ± 9.6 years, 71% women) individuals were obtained from T2-FLAIR. MRI and PET images were normalized into common space, segmented and parcellated into gray matter (GM) regions. The effects of WML on connected GM regions were assessed using the Change in Connectivity (ChaCo) score. Defined for each GM region, ChaCo is the percentage of WM tracts connecting to that region that pass through the WML mask. The regional relationship between ChaCo, glucose uptake and Aß was explored via linear regression. Subcortical regions of the bilateral caudate, putamen, calcarine, insula, thalamus and anterior cingulum had WM connections with the most lesions, followed by frontal, occipital, temporal, parietal and cerebellar regions. Regional analysis revealed that GM with more lesions in connecting WM and thus impaired connectivity had lower FDG-PET (r = 0.20, p<0.05 corrected) and lower PiB uptake (r = 0.28, p<0.05 corrected). Regional regression also revealed that both ChaCo (β = 0.045) and FDG-PET (β = 0.089) were significant predictors of PiB. In conclusion, brain regions with more lesions in connecting WM had lower glucose metabolism and lower Aß deposition.

Inhibition of intestinal tumor formation by deletion of the DNA methyltransferase 3a

Aberrant de novo methylation of DNA is considered an important mediator of tumorigenesis. To investigate the role of de novo DNA methyltransferase 3a (Dnmt3a) in intestinal tumor development, we analyzed the expression of Dnmt3a in murine colon crypts, murine colon adenomas and human colorectal cancer using RNA fluorescence in situ hybridization (FISH), quantitative PCR and immunostaining. Following conditional deletion of Dnmt3a in the colon of APC((Min/+)) mice, we analyzed tumor numbers, genotype of macroadenomas and laser dissected microadenomas, global and regional DNA methylation and gene expression. Our results showed increased Dnmt3a expression in colon adenomas of APC((Min/+)) mice and human colorectal cancer samples when compared with control tissue. Interestingly, in tumor tissue, RNA FISH analysis showed highest Dnmt3a expression in Lgr5-positive stem/progenitor cells. Deletion of Dnmt3a in APC((Min/+)) mice reduced colon tumor numbers by ~40%. Remaining adenomas and microadenomas almost exclusively contained the non-recombined Dnmt3a allele; no tumors composed of the inactivated Dnmt3a allele were detected. DNA methylation was reduced at the Oct4, Nanog, Tff2 and Cdkn1c promoters and expression of the tumor-suppressor genes Tff2 and Cdkn1c was increased. In conclusion, our results show that Dnmt3a is predominantly expressed in the stem/progenitor cell compartment of tumors and that deletion of Dnmt3a inhibits the earliest stages of intestinal tumor development.

Sexually transmitted infections among HIV-infected heavy drinkers in St Petersburg, Russia

The objective of this study was to estimate the prevalence and identify correlates of four sexually transmitted infections (STIs) among HIV-infected Russians reporting heavy alcohol use and recent unprotected sex, we conducted a cross-sectional analysis of baseline data from the HERMITAGE study. The primary outcome was any current STI, based on urine tests for Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis and serological testing for infection with Treponema pallidum. Data on potential demographic and behavioural predictors of STI were obtained from surveys administered at study entry. Of 682 participants, 12.8% (95% confidence interval [CI] 10.3, 15.3) tested positive for at least one STI. In a multivariable model adjusted for gender, age and marital status, only sex trade involvement over the last three months was significantly associated with an increased odds of STI (adjusted odds ratio [AOR] 2.00, 95% CI 1.13, 3.55). Given that STIs were common in this HIV-infected cohort, and that few patient characteristics predicted STI, the current practice of screening HIV-infected Russians for syphilis alone merits re-evaluation.

IR, Raman, SERS and computational study of 2-(benzylsulfanyl)-3,5-dinitrobenzoic acid

FT-IR and FT-Raman spectra of 2-(benzylsulfanyl)-3,5-dinitrobenzoic acid were recorded and analyzed. SERS spectra were recorded in silver colloid, silver electrode and silver substrate. The vibrational wavenumbers were computed using HF and DFT quantum chemical calculation methods. The data obtained from wavenumber calculations are used to assign vibrational bands obtained in infrared and Raman spectra as well as in SERS of the studied molecule. Potential energy distribution was done using GAR2PED program. The geometrical parameters of the title compound are in agreement with the reported similar derivatives. The presence of phenyl ring modes in the SERS spectra suggests a tilted orientation with respect to the metal surface in all cases. In all the three SERS spectra the NO2 moiety shows an enhancement, which indicates the interaction with the metal surface. The first hyperpolarizability is high and the title compound is an attractive object for future studies of nonlinear optics.

D-Dimer assay as a non invasive test for the diagnosis of left atrial Thrombi in Indian patients with Rheumatic MS

BACKGROUND

Systemic embolism is a serious and sometime fatal complication of rheumatic MS.

OBJECTIVE

We assessed the predictive power of D-Dimer level to predict occurrence of left atrial (LA) thrombi in patients with rheumatic mitral stenosis (MS).

METHODS

D-dimer levels were analyzed for 24 patients with rheumatic MS with LA clot and 22 patients with rheumatic MS with no LA clot undergoing transeosophageal echocardiography. A level more than 4 µg/ml was taken as elevated to predict the presence of LA clot in the study groups.

RESULTS

For a cut-off value of 4 µg/ml, sensitivity was 66.67 % and specificity 100 % for prediction of LA clot and AUC 0.710. A cut-off value of less than 1 µg/ml, sensitivity was 91.67 % and 87. 5 % negative predictive value for ruling out presence of LA clot and AUC 0.721.

CONCLUSION

A higher value of D-dimer can predict the possible presence of a LA clot and very low value can predict absence of clot in patients with rheumatic MS.

History of intimate partner violence is associated with sex work but not sexually transmitted infection among HIV-positive female drinkers in Russia

This paper assesses the associations between intimate partner violence (IPV) and sexually transmitted infections (STIs) and sexual risks among HIV-positive female drinkers in St Petersburg, Russia. Survey and STI data were analysed from 285 women in HERMITAGE, a secondary prevention study of HIV-positive heavy drinkers. Logistic and Poisson regression analyses assessed associations of IPV with STI and risky sex. Most women (78%) experienced IPV and 19% were STI positive; 15% sold sex. IPV was not significantly associated with STI, but was with selling sex (adjusted odds ratio = 3.56, 95% confidence interval = 1.02-12.43). In conclusion, IPV is common and associated with sex trade involvement among Russian HIV-positive female drinkers.

Effects of increased image noise on image quality and quantitative interpretation in brain CT perfusion

BACKGROUND AND PURPOSE

There is a desire within many institutions to reduce the radiation dose in CTP examinations. The purpose of this study was to simulate dose reduction through the addition of noise in brain CT perfusion examinations and to determine the subsequent effects on quality and quantitative interpretation.

MATERIALS AND METHODS

A total of 22 consecutive reference CTP scans were identified from an institutional review board-approved prospective clinical trial, all performed at 80 keV and 190 mAs. Lower-dose scans at 188, 177, 167, 127, and 44 mAs were generated through the addition of spatially correlated noise to the reference scans. A standard software package was used to generate CBF, CBV, and MTT maps. Six blinded radiologists determined quality scores of simulated scans on a Likert scale. Quantitative differences were calculated.

RESULTS

For qualitative analysis, the correlation coefficients for CBF (-0.34; P < .0001), CBV (-0.35; P < .0001), and MTT (-0.44; P < .0001) were statistically significant. Interobserver agreements in quality for the simulated 188-, 177-, 167-, 127-, and 44-mAs scans for CBF were 0.95, 0.98, 0.98, 0.95, and 0.52, respectively. Interobserver agreements in quality for the simulated CBV were 1, 1, 1, 1, and 0.83, respectively. For MTT, the interobserver agreements were 0.83, 0.86, 0.88, 0.74, and 0.05, respectively. For quantitative analysis, only the lowest simulated dose of 44 mAs showed statistically significant differences from the reference scan values for CBF (-1.8; P = .04), CBV (0.07; P < .0001), and MTT (0.46; P < .0001).

CONCLUSIONS

From a reference CTP study performed at 80 keV and 190 mAs, this simulation study demonstrates the potential of a 33% reduction in tube current and dose while maintaining image quality and quantitative interpretations. This work can be used to inform future studies by using true, nonsimulated scans.

Experiences of racial discrimination and relation to sexual risk for HIV among a sample of urban black and African American men

This study aimed to examine racial discrimination and relation to sexual risk for HIV among a sample of urban black and African American men. Participants of this cross-sectional study were black and African American men (N = 703) between the ages of 18 and 65 years, recruited from four urban clinical sites in the northeast. Multivariate logistic regression models were used to analyze the relation of reported racial discrimination to the following: (1) sex trade involvement, (2) recent unprotected sex, and (3) reporting a number of sex partners in the past 12 months greater than the sample average. The majority of the sample (96%) reported racial discrimination. In adjusted analyses, men reporting high levels of discrimination were significantly more likely to report recent sex trade involvement (buying and/or selling) (adjusted odds ratio (AOR) range = 1.7-2.3), having recent unprotected vaginal sex with a female partner (AOR = 1.4, 95% confidence interval (CI), 1.1-2.0), and reporting more than four sex partners in the past year (AOR = 1.4, 95% CI, 1.1-1.9). Findings highlight the link between experiences of racial discrimination and men's sexual risk for HIV.

Differential diagnosis of normal pressure hydrocephalus by MRI mean diffusivity histogram analysis

BACKGROUND AND PURPOSE

Accurate diagnosis of normal pressure hydrocephalus is challenging because the clinical symptoms and radiographic appearance of NPH often overlap those of other conditions, including age-related neurodegenerative disorders such as Alzheimer and Parkinson diseases. We hypothesized that radiologic differences between NPH and AD/PD can be characterized by a robust and objective MR imaging DTI technique that does not require intersubject image registration or operator-defined regions of interest, thus avoiding many pitfalls common in DTI methods.

MATERIALS AND METHODS

We collected 3T DTI data from 15 patients with probable NPH and 25 controls with AD, PD, or dementia with Lewy bodies. We developed a parametric model for the shape of intracranial mean diffusivity histograms that separates brain and ventricular components from a third component composed mostly of partial volume voxels. To accurately fit the shape of the third component, we constructed a parametric function named the generalized Voss-Dyke function. We then examined the use of the fitting parameters for the differential diagnosis of NPH from AD, PD, and DLB.

RESULTS

Using parameters for the MD histogram shape, we distinguished clinically probable NPH from the 3 other disorders with 86% sensitivity and 96% specificity. The technique yielded 86% sensitivity and 88% specificity when differentiating NPH from AD only.

CONCLUSIONS

An adequate parametric model for the shape of intracranial MD histograms can distinguish NPH from AD, PD, or DLB with high sensitivity and specificity.

Hearing loss in rural population : the etiology

Out of the five sensations, hearing is a major one. The gross impairment of hearing especially in the children lead to lack of development of speech and makes the person grossly handicapped. This study consisting of 758 cases from rural area having hearing impairment, was aimed to findout the various aetiological factors resulting in hearing loss. 62.2% of cases belonged to 0-20 years age group. Otitis media (57.25%) was the commonest aetiological factor. Conductive hearing loss was the commonest type of hearing loss in otitis media. 86.17% cases of otitis media were in age group 0-20 years.

Endoscopic transcanal myringoplasty-A study

Aim of this study was to evaluate the role of rigid endoscope in the management of dry central perforation of the tympanic membrane and to compare the results of endoscopic myringoplasty with that of conventional myringoplasty using microscope. In endoscopic group there was 90% graft uptake rate as compared to 85% in microscopic group. The results of endoscopic myringoplasty are comparable to the conventional myringoplasty done under operating microscope and there is no significant difference between the gain in A-B gap in either group.

Are All Odontogenic Keratocysts Keratocystic Odontogenic Tumors? Correlation between Imaging Features and Epithelial Cell Proliferation

This study was to correlate and analyze the imaging features and epithelial cell proliferation pattern in different cases of keratocystic odontogenic tumors (KCOT) and study the role of inflammation using proliferative markers and different radiographic patterns of KCOT to determine its biological behavior. One hundred and eighty-six cases of KCOT were taken together and grouped based on radiographic patterns. Forty cases were randomly selected and stained using a proliferating cellular nuclear antigen marker. The correlation between imaging and epithelial proliferation with and without inflammation was determined. Unilocular variety is the most common type of KCOT, showing least epithelial proliferation of all the patterns. More than 50% of the multilocular KCOTs were associated with inflammation, showing an enhanced rate of epithelial proliferation. Results were subjected to statistical analysis. Different rates of epithelial proliferation of the different patterns suggested that all odontogenic keratocysts do not behave like tumors and that aggressive treatment should be reserved for selective cases only depending on radiographic and other histopathological parameters such as inflammation.