Biophysical characterization of human-cell-expressed, full-length κI O18/O8, AL-09, λ6a, and Wil immunoglobulin light chains

Immunoglobulin light chain (AL) amyloidosis involves the deposition of insoluble monoclonal AL protein fibrils in the extracellular space of different organs leading to dysfunction and death. Development of methods to efficiently express and purify AL proteins with acceptable standards of homogeneity and structural integrity has become critical to understand the in vitro and in vivo aspects of AL protein aggregation, and thus the disease progression. In this study, we report the biophysical characterization of His-tagged and untagged versions of AL full-length (FL) κI and λ6 subgroup proteins and their mutants expressed from the Expi293F human cell line. We used an array of biophysical and biochemical methods to analyze the structure and stability of the monomers, oligomerization states, and thermodynamic characteristics of the purified FL proteins and how they compare with the bacterially expressed FL proteins. Our results demonstrate that the tagged and untagged versions of FL proteins have comparable stability to proteins expressed in bacterial cells but exhibit multiple unfolding transitions and reversibility. Non-reducing SDS-PAGE and analytical ultracentrifugation analysis showed presence of monomers and dimers, with an insignificant amount of higher-order oligomers, in the purified fraction of all proteins. Overall, the FL proteins were expressed with sufficient yields for biophysical studies and can replace bacterial expression systems.

Patient Reported Financial Distress and its Association with Quality of Life and Symptom Burden in Cancer Patients Reporting to a Public Facility in LMIC

PURPOSE/OBJECTIVE(S)

Financial distress (FD) associates with worse quality of life (QoL) and there is paucity of literature from low middle income setting (LMIC). We investigated the prevalence & impact of subjective FD on QoL & symptom burden in advanced cancer patients, reporting to a public facility.

MATERIALS/METHODS

Patients aged ≥18yrs with a diagnosis of cancer within 3months and without prior treatment were accrued. Subjective FD was assessed by EORTC QLQ-C30 and symptoms were assessed by ESAS-R at baseline and 3 months. Patients were classified as experiencing FD if they answered ≥2 on a Likert scale question (1-4 points) asking about FD and dichotomized as Grp 1: No FD and Grp 2: FD. Mean change in score was calculated by subtracting the baseline from the 3-month score for each subscale, minimal important difference (MID) was defined using an anchor of ≥ 10-point compared to baseline for Global Qol and compared between groups. We used Mann Whitney, independent sample t test and Fisher's exact test for determining the association between FD and QoL and symptom burden. A p-value < 0.05 was considered statistically significant.

RESULTS

Of the 100 patients participating in the study, 69% reported subjective financial distress at baseline, 10% had insurance coverage, 27% used distressed financing (borrowing :21%; sold off assets:6%) and debt accumulation was seen in 34% patients. Cost reduction strategies were adopted by 98% patients. Mean Global Health (GH), physical (PF), emotional function (EF) was significantly worse at all time-points in FD patients. Physical (pain, tiredness) and psychological symptom scores (anxiety, depression) were significantly higher at all time points for FD patients. Mean change score for subscales of QoL and symptom burden was not significantly different between groups from baseline to 3 months (Table1).MID for deterioration of Global Qol was Grp 1 vs 2; 21.1% vs 32.7%, p = 0.504.

CONCLUSION

Two-thirds of patients have FD at presentation and report worse quality of life and symptom burden at all time-points. Presence of FD is not associated with significant change in QoL scores or symptom burden over 3 months. Measures are warranted to screen and reduce FD.

Pathologic light chain amyloidosis oligomer detection in urinary extracellular vesicles as a diagnostic tool for response and progression of disease

Light Chain (AL) Amyloidosis is a plasma cell dyscrasia producing amyloidogenic light chains (LC) that misfold and form amyloid deposits that cause damage in vital organs, primarily the heart and kidneys. Urinary extracellular vesicles (uEVs) are nanoparticles produced by renal epithelial cells throughout the nephron. We previously showed that uEVs from active renal AL amyloidosis patients contain LC oligomers that are large (&gt;250kDa), resistant to heat and chemical denaturation, but of low abundance. Renal dysfunction in AL amyloidosis results in high urine protein, compounding technical challenges to use uEVs as analytical tools. In this study, we assess the use of uEVs as analytical diagnostic tools for response and disease progression in AL amyloidosis. Our results suggest that uEV protein concentration, urine volume, and particle concentrations are not directly correlated. Multiple strategies for overcoming non-specific antibody binding in uEV samples were validated in our study. We demonstrated that the sensitivity for pre-clinical testing is improved with a urine sample requirement algorithm that we developed. The findings of our study will provide a pathway toward development of critically needed tools for patient management. Sensitive detection of LC oligomers from a non-invasive urine sample rather than an invasive renal biopsy will reduce patient burden and healthcare costs. The ability to detect LC oligomers in patients with renal progression, despite positive hematologic response; will allow clinicians to confidently treat, but not overtreat, patients at risk of ongoing significant renal injury.

Aerosol Loading and Radiation Budget Perturbations in Densely Populated and Highly Polluted Indo-Gangetic Plain by COVID-19: Influences on Cloud Properties and Air Temperature

Aerosols emitted in densely populated and industrialized Indo-Gangetic Plain, one of the most polluted regions in the world, modulate regional climate, monsoon, and Himalayan glacier retreat. Thus, this region is important for understanding aerosol perturbations and their resulting impacts on atmospheric changes during COVID-19 lockdown period, a natural experimental condition created by the pandemic. By analyzing 5 years (2016-2020) data of aerosols and performing a radiative transfer calculation, we found that columnar and near-surface aerosol loadings decreased, leading to reductions in radiative cooling at the surface and top of the atmosphere and atmospheric warming during lockdown period. Further, satellite data analyses showed increases in cloud optical thickness and cloud-particle effective radius and decrease in lower tropospheric air temperature during lockdown period. These results indicate critical influences of COVID-19 lockdown on regional climate and water cycle over Indo-Gangetic Plain, emphasizing need for further studies from modeling perspectives.

Early events in light chain aggregation at physiological pH reveal new insights on assembly, stability, and aggregate dissociation

Early events in immunoglobulin light chain (AL) amyloid formation are especially important as some early intermediates formed during the aggregation reaction are cytotoxic and play a critical role in the initiation of amyloid assembly. We investigated the early events in in vitro aggregation of cardiac amyloidosis AL proteins at pH 7.4. In this study we make distinctions between general aggregation and amyloid formation. Aggregation is defined by the disappearance of monomers and the detection of sedimentable intermediates we call non-fibrillar macromolecular (NFM) intermediates by transmission electron microscopy (TEM). Amyloid formation is defined by the disappearance of monomers, Thioflavin T fluorescence enhancement, and the presence of fibrils by TEM. All proteins aggregated at very similar rates via the formation of NFM intermediates. The condensed NFM intermediates were composed of non-native monomers. Amyloid formation and amyloid yield was variable among the different proteins. During the stationary phase, all proteins demonstrated different degrees of dissociation. These dissociated species could play a key role in the already complex pathophysiology of AL amyloidosis. The degree of dissociation is inversely proportional to the amyloid yield. Our results highlight the importance and physiological consequences of intermediates/fibril dissociation in AL amyloidosis.

Light chain amyloidosis induced inflammatory changes in cardiomyocytes and adipose-derived mesenchymal stromal cells

Light chain (AL) amyloidosis is a progressive, degenerative disease characterized by the misfolding and amyloid deposition of immunoglobulin light chain (LC). The amyloid deposits lead to organ failure and death. Our laboratory is specifically interested in cardiac involvement of AL amyloidosis. We have previously shown that the fibrillar aggregates of LC proteins can be cytotoxic and arrest the growth of human RFP-AC16 cardiomyocytes in vitro. We showed that adipose-derived mesenchymal stromal cells (AMSC) can rescue the cardiomyocytes from the fibril-induced growth arrest through contact-dependent mechanisms. In this study, we examined the transcriptome changes of human cardiomyocytes and AMSC in the presence of AL amyloid fibrils. The presence of fibrils causes a 'priming' immune response in AMSC associated with interferon associated genes. Exposure to AL fibrils induced changes in the pathways associated with immune response and extracellular matrix components in cardiomyocytes. We also observed upregulation of innate immune-associated transcripts (chemokines, cytokines, and complement), suggesting that amyloid fibrils initiate an innate immune response on these cells, possibly due to phenotypic transformation. This study corroborates and expands our previous studies and identifies potential new immunologic mechanisms of action for fibril toxicity on human cardiomyocytes and AMSC rescue effect on cardiomyocytes.

Mechanistic Insights into the Early Events in the Aggregation of Immunoglobulin Light Chains

Little is known about the mechanism of amyloid assembly in immunoglobulin light chain (AL) amyloidosis, in contrast to other amyloid diseases. Early events in the aggregation pathway are especially important, as these soluble species could be cytotoxic intermediates playing a critical role in the initiation of the amyloid assembly. In this work, we discuss the mechanism of the early events in in vitro fibril formation of immunoglobulin light chain AL-09 and AL-12 (involved in cardiac amyloidosis) and its germline (control) protein κI O18/O8. Previous work from our laboratory showed that AL-12 adopts a canonical dimer conformation (like the germline protein), whereas AL-09 presents an altered dimer interface as a result of somatic mutations. Both AL-12 and AL-09 aggregate with similar rates and significantly faster than the germline protein. AL-09 is the only protein in this study that forms stable oligomeric intermediates during the early stages of the aggregation reaction with some structural rearrangements that increase the thioflavin T fluorescence but maintain the same number of monomers in solution. The presence of the restorative mutation AL-09 H87Y changes the kinetics and the aggregation pathway compared to AL-09. The single restorative mutation AL-12 R65S slightly delayed the overall rate of aggregation as compared to AL-12. Collectively, our study provides a comprehensive analysis of species formed during amyloid nucleation in AL amyloidosis, shows a strong dependence between the altered dimer conformation and the formation of stable oligomeric intermediates, and sheds light on the structural features of amyloidogenic intermediates associated with cellular toxicity.

Relationship between body mass index and percentage of body fat, estimated by bio-electrical impedance among adult females in a rural community of North India: A cross-sectional study

Introduction:

Body adiposity measured by percentage of body fat (BF%) is found to be better predictor of cardiovascular morbidity and mortality than body mass index (BMI). Limited information exists showing relationship between BMI and BF% in North Indian population.

Objectives:

To study the relationship between BMI and BF% among North Indian adult females across various age strata and level of BMI.

Materials and Methods:

This was a cross-sectional study conducted at Ballabgarh Health and Demographic Surveillance Site (HDSS) among randomly selected females. BMI using standard techniques and BF% using bioelectrical impedance analysis was estimated. Linear regression was performed using general linear model with BF% as dependent variable and BMI as main independent variable.

Results:

Mean (±2 SD) age of participants was 41.3 ± 15.7 years. Mean BMI (±SD) was 23.3 (±4.6) kg/m², whereas mean fat mass (±2 SD) and BF% (±95% CI) was 19.2 (±7.9) kg and 33.6 (±6.9) %. BMI and BF% were highly correlated among obese (r = 0.77), whereas least correlated (r = 0.32) in underweight females. Across age strata, correlation between BMI and BF% was maximum in 18–35 years age group (r = 0.95), whereas least in females ≥56 years (r = 0.67). Age and BMI together predicted 73% of variability in BF% in hierarchical linear regression model.

Conclusions:

In this population, we have found strong correlation between BMI and BF% particularly at higher level of BMI and in younger females. There is need to conduct more robust prospective longitudinal studies to assess BF%, which is a better predictor of cardiovascular morbidity and mortality.

Immunoglobulin light chain amyloid aggregation

Light chain (AL) amyloidosis is a devastating, complex, and incurable protein misfolding disease. It is characterized by an abnormal proliferation of plasma cells (fully differentiated B cells) producing an excess of monoclonal immunoglobulin light chains that are secreted into circulation, where the light chains misfold, aggregate as amyloid fibrils in target organs, and cause organ dysfunction, organ failure, and death. In this article, we will review the factors that contribute to AL amyloidosis complexity, the findings by our laboratory from the last 16 years and the work from other laboratories on understanding the structural, kinetics, and thermodynamic contributions that drive immunoglobulin light chain-associated amyloidosis. We will discuss the role of cofactors and the mechanism of cellular damage. Last, we will review our recent findings on the high resolution structure of AL amyloid fibrils. AL amyloidosis is the best example of protein sequence diversity in misfolding diseases, as each patient has a unique combination of germline donor sequences and multiple amino acid mutations in the protein that forms the amyloid fibril.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

An Aggregate Weight-Normalized Thioflavin-T Measurement Scale for Characterizing Polymorphic Amyloids and Assembly Intermediates

The red shift in the fluorescence excitation spectra of thioflavin dyes upon binding to fibrils has been a boon to the amyloid field, offering simple and effective methods for the qualitative detection of amyloid in tissue samples and for quantitation of particular fibril preparations with gravimetric linearity. The quantitative aspect of the thioflavin T (ThT) response, however, comes with an important caveat that bestows both significant limitations and great untapped power. It is now well established that amyloid fibrils of different proteins, as well as polymorphic fibrils of the same protein, can exhibit vastly different ThT fluorescence intensities for the same weight concentration of aggregates. Furthermore, the aggregated intermediates commonly observed in amyloid assembly reactions can exhibit aggregate weight-normalized (AWN) ThT fluorescence intensities that vary from essentially zero through a wide range of intermediate values before reaching the intensity of homogeneous, mature amyloid. These features make it very difficult to quantitatively interpret, without additional data, the time-dependent development of ThT fluorescence intensity in an assembly reaction. In this chapter, we describe a method for coupling ex situ ThT fluorescence determinations with an analytical HPLC supported sedimentation assay (also described in detail) that can provide significant new insights into amyloid assembly reactions. The time dependent aggregation data provided by the sedimentation assay reveals a time course of aggregation that is largely independent of aggregate properties. In addition, the combination of these data with ThT measurements of the same reaction time points reveals important aspects of average aggregate structure at each time point. Examples of the use and potential value of AWN-ThT measurements during amyloid assembly Aβ and polyglutamine peptides are provided.

T cell suppression in the bone marrow of visceral leishmaniasis patients: impact of parasite load

Visceral leishmaniasis (VL) is a disseminated and lethal disease of reticulo-endothelial system caused by protozoan parasites Leishmania donovani and L. infantum, which are known to induce host T cell suppression. To understand the impact of parasite load on T cell function, the present was focused on parasite load with T cell function in bone marrow of 26 VL patients. We observed significant enrichment of forkhead box protein 3 (FoxP3)⁺ (P = 0·0003) and interleukin (IL)-10⁺ FoxP3⁺ regulatory T cells (T_reg ) (P = 0·004) in the bone marrow (BM) of patients with high parasite load (HPL) compared with low parasite load (LPL). Concordantly, T effector cells producing interferon (IFN)-γ (P = 0·005) and IL-17A (P = 0·002) were reduced in the BM of HPL. Blocking of T_reg -cell derived suppressive cytokines [(IL-10 and transforming growth factor (TGF)-β] rescued the effector T cells and their functions. However, it was observed that TGF-β levels were dominant, favouring T_reg cell differentiation. Furthermore, the low ratio of IL-6/TGF-β favours the suppressive milieu in HPL patients. Here we show the change in levels of various cytokines with the parasitic load during active VL, which could be helpful in devising newer immunotherapeutic strategies against this disease.

Differences in Protein Concentration Dependence for Nucleation and Elongation in Light Chain Amyloid Formation

Light chain (AL) amyloidosis is a lethal disease characterized by the deposition of the immunoglobulin light chain into amyloid fibrils, resulting in organ dysfunction and failure. Amyloid fibrils have the ability to self-propagate, recruiting soluble protein into the fibril by a nucleation-polymerization mechanism, characteristic of autocatalytic reactions. Experimental data suggest the existence of a critical concentration for initiation of fibril formation. As such, the initial concentration of soluble amyloidogenic protein is expected to have a profound effect on the rate of fibril formation. In this work, we present in vitro evidence that fibril formation rates for AL light chains are affected by the protein concentration in a differential manner. De novo reactions of the proteins with the fastest amyloid kinetics (AL-09, AL-T05, and AL-103) do not present protein concentration dependence. Seeded reactions, however, exhibited weak protein concentration dependence. For AL-12, seeded and protein concentration dependence data suggest a synergistic effect for recruitment and elongation at low protein concentrations, while reactions of κI exhibited poor efficiency in nucleating and elongating preformed fibrils. Additionally, co-aggregation and cross seeding of κI variable domain (V_L) and the κI full length (FL) light chain indicate that the presence of the constant domain in κI FL modulates fibril formation, facilitating the recruitment of κI V_L. Together, these results indicate that the dominant process in fibril formation varies among the AL proteins tested with a differential dependence of the protein concentration.

Cell Damage in Light Chain Amyloidosis: FIBRIL INTERNALIZATION, TOXICITY AND CELL-MEDIATED SEEDING

Light chain (AL) amyloidosis is an incurable human disease characterized by the misfolding, aggregation, and systemic deposition of amyloid composed of immunoglobulin light chains (LC). This work describes our studies on potential mechanisms of AL cytotoxicity. We have studied the internalization of AL soluble proteins and amyloid fibrils into human AC16 cardiomyocytes by using real time live cell image analysis. Our results show how external amyloid aggregates rapidly surround the cells and act as a recruitment point for soluble protein, triggering the amyloid fibril elongation. Soluble protein and external aggregates are internalized into AC16 cells via macropinocytosis. AL amyloid fibrils are shown to be highly cytotoxic at low concentrations. Additionally, caspase assays revealed soluble protein induces apoptosis, demonstrating different cytotoxic mechanisms between soluble protein and amyloid aggregates. This study emphasizes the complex immunoglobulin light chain-cell interactions that result in fibril internalization, protein recruitment, and cytotoxicity that may occur in AL amyloidosis.

Influence of alcohol on condom use pattern during non-spousal sexual encounter in male migrant workers in north India

CONTEXT

Migrant workers constitute an important risk group for Human Immunodeficiency Virus/Acquired Immuno-Deficiency Syndrome transmission in India. Alcohol consumption before sexual intercourse has been postulated to influence condom use practices. This study aimed to assess this association with regard to non-spousal sexual encounters among male migrant workers in northern India.

MATERIALS AND METHODS

A cross-sectional facility-based survey was conducted in 2011. Male migrant workers aged ≥18 years, who were born outside Haryana, who had moved to the current location after 15 years of age,had worked in the current factory for at least 1 year, who were willing to participate and were able to give written, informed consent were included in the study. A consecutive sampling was performed. Descriptive, bivariate and multiple logistic regression analyses were carried out.

RESULTS

A total of 162 participants reported having experienced non-spousal sexual encounters in the last 1 year. The proportion of men who reported not having used a condom at their last non-spousal sexual encounter was 59.3%, and 78.4% of the men reported having consumed alcohol in the last 1 year. About 48.1% of men reported having consumed alcohol before their last non-spousal sexual encounter. Men who consumed alcohol were three times more likely to not use a condom at their last non-spousal sexual encounter (OR = 3.1, 95% CI: 1.5-6.4). This association persisted even after adjusting for relevant confounders.

CONCLUSION

Alcohol consumption had a negative influence on condom use during non-spousal sexual encounter among male migrant workers. An integrated approach to promote condom use and reduce alcohol consumption among migrant men needs to be undertaken through targeted intervention strategies.

Immunostimulatory potential and proteome profiling of Leishmania donovani soluble exogenous antigens

Isolation of the soluble exogenous antigens (SEAgs), its immune response study and proteome profiling is an essential prerequisite for understanding the molecular pathogenesis of Leishmania donovani. The immunostimulatory potential of L. donovani SEAgs, purified from culture of L. donovani clinical isolate, was evaluated for their ability to induce cellular responses in treated/cured hamsters. SEAgs induced significant proliferative responses in lymphocytes (SI 5.6 ± 2.3; P < 0.01) isolated from cured hamster. In addition, significant NO production in response to SEAgs was also noticed in macrophages of hamsters, mouse and human cell lines (J774A-1 and THP1). Western blot analyses with antibodies against proteophosphoglycan (PPG; surface-expressed and secreted molecule) of L. donovani revealed that PPG molecules are also present in L. donovani SEAgs. Mass spectrometry (MS)-based proteome analysis of 12 protein bands of SEAgs through MALDI-TOF/TOF endorsed the identification of some Th1-stimulatory immunogenic proteins. These immunogenic proteins may offer increased hope for the discovery of new promising vaccine candidates against visceral leishmaniasis (VL). The overall results suggest that immunostimulatory molecules are present in the SEAgs, which may be further exploited, for developing a subunit vaccine against VL a fatal human disease.

Band offset at TiO2/MDMO PPV and TiO2/PEDOT PSS interfaces studied using photoelectron spectroscopy

We report band alignment and band offset studies across the interfaces of hetero-structures of TiO₂ with MDMO PPV and PEDOT PSS using photoelectron spectroscopy.

Coating doxorubicin-loaded nanocapsules with alginate enhances therapeutic efficacy against Leishmania in hamsters by inducing Th1-type immune responses

BACKGROUND AND PURPOSE

The aim of the present study was to evaluate the immunomodulatory and chemotherapeutic potential of alginate-(SA) coated nanocapsule (NCs) loaded with doxorubicin (SA-NCs-DOX) against visceral leishmaniasis in comparison with nano-emulsions containing doxorubicin (NE-DOX).

EXPERIMENTAL APPROACH

NE-DOX was prepared using low-energy emulsification methods. Stepwise addition of protamine sulphate and SA in a layer-by-layer manner was used to form SA-NCs-DOX. SA-NCs-DOX, NE-DOX and Free DOX were compared for their cytotoxicity against Leishmania donovani-infected macrophages in vitro and generation of T-cell responses in infected hamsters in vivo.

KEY RESULTS

Size and ζ potential of the NE-DOX and SA-NCs-DOX formulations were 310 ± 2.1 nm and (-)32.6 ± 2.1 mV, 342 ± 4.1 nm and (-)29.3 ± 1.2 mV respectively. SA-NCs-DOX was better (1.5 times) taken up by J774A.1 macrophages compared with NE-DOX. SA-NCs -DOX showed greater efficacy than NE-DOX against intramacrophagic amastigotes. SA-NCs-DOX treatment exhibited enhanced apoptotic efficiency than NE-DOX and free DOX as evident by cell cycle analysis, decrease in mitochondrial membrane potential, ROS and NO production. T-cell responses, when assessed through lymphoproliferative responses, NO production along with enhanced levels of iNOS, TNF-α, IFN-γ and IL-12 were found to be up-regulated after SA-NCs-DOX, compared with responses to NE-DOX in vivo. Parasitic burden was decreased in Leishmania-infected hamsters treated with SA-NCs-DOX, compared with NE-DOX.

CONCLUSIONS AND IMPLICATIONS

Our results provide insights into the development of an alternative approach to improved management of leishmaniasis through a combination of chemotherapy with stimulation of the innate immune system.

Teaching community medicine to medical undergraduates-learning by doing: our experience of rural posting at All India Institute of Medical Sciences, New Delhi, India

BACKGROUND

The goal of medical education is to ensure that the medical graduate has acquired broad public health competencies needed to solve the health problems of the community. We present the current teaching of community medicine to medical students of the All India Institute of Medical Sciences (AIIMS), New Delhi during their 5-week posting at the rural centre at Ballabgarh, Haryana.

METHODS

The teaching activities consist of field visits to different levels of health facilities and meeting with health workers, epidemiological exercises, a community-based exercise, posting in inpatient and outpatient departments of a secondary hospital, and domiciliary visits to families of patients. These are spread over 80 sessions of about 200 hours. There is very little didactic teaching and the assessment is broad-based. The evaluation of the posting was based on comparison of blinded pre- and post-posting assessments as well as anonymous feedback of the posting by the students.

RESULTS

There was a significant increase in the mean scores of all components of the posting-epidemiology (5.1 to 8.4), health systems (6.8 to 9.3) and clinical (8.0 to 10.8). The posting did not result in a better understanding of a public health approach as compared to a clinical approach. The feedback provided by students was generally positive for all activities with 94% of them rating it as good or very good.

CONCLUSION

The teaching of community medicine can be made more practical and interesting without compromising on learning. However, despite such a programme, getting medical students to develop a public health approach is a daunting task.

Prevalence of chronic kidney diseases and its determinants among perimenopausal women in a rural area of North India: A community-based study

The burden of noncommunicable diseases is rising in India. A high prevalence of lifestyle-related diseases in perimenopausal women in the community makes them vulnerable to chronic kidney diseases (CKD). A cross-sectional community-based study was carried out among women >35 years of age in the village of Ballabgarh, Haryana (north India). Eligible women were selected by the probability proportionate to size sampling method. Estimation of glomerular filtration rate (GFR) was carried out by using the age- and body surface area (BSA)-adjusted Cockcroft–Gault (CG) and modification of diet in renal disease (MDRD) equations. Association of risk factors such as obesity, hyperlipidemia, hypertension, and diabetes mellitus with CKD was also assessed using multivariate logistic regression analysis. A total of 455 women were studied. The prevalence of low GFR (<60 mL/min/1.73 m²) by the CG/BSA equations and MDRD equation was found to be 18.2% (95% confidence interval 14.6, 21.8) and 5.9% (95% confidence interval 3.7, 8.1), respectively. Obesity (odds ratio 15.5) (P = 0.002), hyperlipidemia (odds ratio: 2.5) (P = 0.017), and age (P < 0.001) were significantly associated with reduced GFR on multivariate logistic regression analysis. This study observed a high prevalence of CKD and its risk factors among perimenopausal women in a rural community in north India. The study highlights the need of a multipronged, community-based intervention strategy that includes a high-risk screening approach and awareness generation about CKD and its risk factors in the community.

Nerve injuries sustained during warfare: part II: Outcomes

The outcomes of 261 nerve injuries in 100 patients were graded good in 173 cases (66%), fair in 70 (26.8%) and poor in 18 (6.9%) at the final review (median 28.4 months (1.3 to 64.2)). The initial grades for the 42 sutures and graft were 11 good, 14 fair and 17 poor. After subsequent revision repairs in seven, neurolyses in 11 and free vascularised fasciocutaneous flaps in 11, the final grades were 15 good, 18 fair and nine poor. Pain was relieved in 30 of 36 patients by nerve repair, revision of repair or neurolysis, and flaps when indicated. The difference in outcome between penetrating missile wounds and those caused by explosions was not statistically significant; in the latter group the onset of recovery from focal conduction block was delayed (mean 4.7 months (2.5 to 10.2) vs 3.8 months (0.6 to 6); p = 0.0001). A total of 42 patients (47 lower limbs) presented with an insensate foot. By final review (mean 27.4 months (20 to 36)) plantar sensation was good in 26 limbs (55%), fair in 16 (34%) and poor in five (11%). Nine patients returned to full military duties, 18 to restricted duties, 30 to sedentary work, and 43 were discharged from military service. Effective rehabilitation must be early, integrated and vigorous. The responsible surgeons must be firmly embedded in the process, at times exerting leadership.

Nerve injuries sustained during warfare: part I--Epidemiology

We describe 261 peripheral nerve injuries sustained in war by 100 consecutive service men and women injured in Iraq and Afghanistan. Their mean age was 26.5 years (18.1 to 42.6), the median interval between injury and first review was 4.2 months (mean 8.4 months (0.36 to 48.49)) and median follow-up was 28.4 months (mean 20.5 months (1.3 to 64.2)). The nerve lesions were predominantly focal prolonged conduction block/neurapraxia in 116 (45%), axonotmesis in 92 (35%) and neurotmesis in 53 (20%) and were evenly distributed between the upper and the lower limbs. Explosions accounted for 164 (63%): 213 (82%) nerve injuries were associated with open wounds. Two or more main nerves were injured in 70 patients. The ulnar, common peroneal and tibial nerves were most commonly injured. In 69 patients there was a vascular injury, fracture, or both at the level of the nerve lesion. Major tissue loss was present in 50 patients: amputation of at least one limb was needed in 18. A total of 36 patients continued in severe neuropathic pain. This paper outlines the methods used in the assessment of these injuries and provides information about the depth and distribution of the nerve lesions, their associated injuries and neuropathic pain syndromes.

High prevalence and low awareness, treatment and control of hypertension in Asian Indian women

Hypertension is an important public health problem in India. To determine its prevalence, awareness, treatment and control among women, we performed a nationwide study. Population-based studies among women aged 35-70 years were performed in four urban and five rural locations. Stratified sampling was performed and we enrolled 4608 (rural 2604 and urban 2004) of the targeted 8000 (57%). Demographic details, medical history, diet, physical activity, anthropometry and blood pressure (BP) were recorded. Descriptive statistics are reported. Logistic regression was performed to determine the association of hypertension and its awareness, treatment and control with socioeconomic factors. Age-adjusted prevalence of hypertension (known or BP≥140/≥90 mm Hg) was observed in 1672 women (39.2%) (rural 746, 31.5%; urban 926, 48.2%). Significant determinants of hypertension were urban location, greater literacy, high dietary fat, low fibre intake, obesity and truncal obesity (P<0.01). Hypertension awareness was noted in 727 women (42.8%), more in urban (529, 56.8%) than in rural (198, 24.6%). Of these, 38.6% of the women were on treatment (urban 35.7, rural 46.5) and of those treated, controlled blood pressure (<140 and <90 mm Hg) was observed in 21.5% (urban 28.3 vs 10.2). Among hypertensive subjects, treatment was noted in 18.3% (rural 13.1, urban 22.5) and control in 3.9% (rural 1.3, urban 5.9). A significant determinant of low awareness, treatment and control was rural location (multivariate-adjusted P<0.05). There is a high prevalence of hypertension in middle-aged Asian Indian women. Very low awareness, treatment and control status are observed.

A review of the epidemiology of diabetes in rural India

OBJECTIVE

To describe the extent of problem of diabetes in rural India based on review of available literature and examine the secular trends over a period of 15 years i.e. from 1994 to 2009.

METHODS

A systematic search was performed using electronic as well as manual methods. Studies providing details of sample size, age group of participants, criteria used for diagnosis, along with the prevalence of any of the three outcomes of interest i.e. diabetes mellitus, impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), were included.

RESULTS

Analysis of secular trends reveals an increase in diabetes prevalence among rural population at a rate of 2.02 per 1000 population per year. The rate of increase was high in males (3.33 per 1000 per year) as compared to females (0.88 per 1000 per year). High prevalence of IFG and IGT has been observed in southern and northern parts of the country.

CONCLUSION

The prevalence of diabetes is rising in rural India. There is a large pool of subjects with IFG and IGT at high risk of conversion to overt diabetes. Population-level and individual-level measures are needed to combat this increasing burden of diabetes.

Development and performance evaluation of amphotericin B transfersomes against resistant and sensitive clinical isolates of visceral leishmaniasis

The present study was aimed to assess the efficacy of developed transfersome (TF-3) formulation bearing amphotericin B (AmB) against sensitive and resistant clinical isolates of L donovani and compared with conventional liposomal formulation (F-2) and free AmB (F-1). The skin permeation of AmB from TF-3 was performed using Franz diffusion cell using rat skin which showed fickian diffusion across the skin. When tested against L. donovani (intramacrophagic amastigotes), it has been observed that TF was more effective than F-1 and F-2 formulation in sensitive and resistant clinical isolates. The data provides evidences that the TF formulation owing to its fluidized behaviour imparted by sodium deoxycholate, enables to penetrate well in the infected cells and thus provide enhanced activity. The permeation study also supports this data as the flux value of AmB through TF formulation was 1.5 fold higher compared to conventional liposomes suggesting improved penetration and better partitioning in skin layers. Implicit to this preliminary data it is evident that the AmB loaded TF formulation has potential as alternate chemotherapeutic approach to control of VL. Potential utilities of novel formulation as a transdermal delivery of AmB for leishmaniasis necessitates further elaborated investigations which is underway in our laboratory.

Simulation and modeling of laser-tissue interactions based on a liposome-dye system

This work presents an overview of the use of liposomes for targeted delivery of photosensitizers to tumors for Photodynamic Therapy (PDT). It assesses the results of a quantitative model to explain the interaction of short-pulsed lasers (in the nanosecond and picosecond domains) with a liposome-dye complex in terms of a localized photo-induced thermal mechanism. Incorporation of an organic dye (sulforhodamine) within lipid vesicles has been investigated in conjunction with the effect of laser irradiation on the integrity of the liposome-dye complex. The variation of the absorption coefficient as a function of wavelength for dye-encapsulated liposomes before and after laser-induced release of dye was studied and modeled. The commercial software Mathematica was used to develop a Gaussian model for the energy absorption by the liposome-dye complex. Dye release from 3 microm - liposome encapsulating 25 mM aqueous solution of sulforhodamine dye was studied using 8 ns laser pulses at the second harmonic of the Nd:YAG laser (at 532 nm) and compared with dye release employing 25 ps - laser pulses. In addition, the temperature-dependence of the dye release has been included in the photo-thermal model.

Differential transcriptional expression following thidiazuron-induced callus differentiation developmental shifts in rice

Very little is known about molecular events associated with callus differentiation in indica rice. The genes expressed differentially during shoot meristem initiation were identified on genomic arrays applied to efficiently regenerating rice calli. A thidiazuron (TDZ; N-phenyl-N-thiadiazol-1,2,3-5,ylurea)-dependent regeneration protocol was developed for efficient embryogenesis in indica rice. The regenerating embryogenic calli induced by TDZ for 10 days showed transcriptional modulation of a number of genes associated with photosynthesis, hormone metabolism, plant development, signal transduction, light response, and plant defense. Eighteen candidate miRNAs were predicted to target the genes expressed differentially in the embryogenic calli grown in TDZ-containing medium. The majority of the photosynthesis-related genes up-regulated in differentiating calli were not expressed or were down-regulated in developing seeds and inflorescences. Most of the genes down-regulated in differentiating calli were up-regulated in developing seeds. The transcriptome of differentiating callus most closely resembled that of the germinating whole seed.