Assessment of the relationship of systemic vascular dysfunction and cardiac autonomic neuropathy (CAN) with diabetic retinopathy.

Context: Diabetic retinopathy, a form of microvasculopathy, is the leading cause of the visual abnormality. However, there is no conclusive evidence of the relationship of systemic vascular dysfunction with retinal microvasculopathy. In addition, diabetes-associated cardiac autonomic neuropathy may also compromise vascular function. Aims: The present study intends to correlate arterial stiffness, endothelial function, and heart rate variability (HRV) as a standardized measure of cardiac autonomic neuropathy with diabetic retinopathy. Settings and Design: The present cross-sectional, observational study was conducted in the Department of Physiology. Materials and Methods: Twenty subjects were recruited in group 1 (T2DM, type 2 diabetes mellitus patients, without retinopathy) and group 2 (T2DM with retinopathy). The vascular parameters such as heart rate, peripheral and central blood pressure, augmentation index [AIx (%)], brachial -ankle pulse wave velocity (baPWV), and reactive hyperaemia index (RHI) were recorded. Statistical Analysis Used: Independent sample t-test (for parametric data) and Mann-Whitney U test (for non-parametric data) were employed to compare the variables of two groups. Spearman correlation was used to examine the relationship among the parameters. Linear regression analysis was performed to examine the important vascular predictor for diabetic retinopathy. Results: baPWV was significantly higher in group 2 than in group 1 and positively associated with group 2. RHI was significantly less in group 2 than group 1 and negatively associated with group 2. Among HRV metrics, standard deviation of successive differences (SDSD), root mean square of successive differences between normal heartbeats (RMSSD), and high frequency (HF) power were significantly decreased in group 2 than in group 1. SDSD, RMSSD, and HF power were negatively associated with group 2. RHI emerged as a significant predictor of diabetic retinopathy following linear regression. Conclusions: Overall, the result of the present study indicates that metabolic dysregulation of glucose may affect the normal functioning of the autonomic nervous system and vascular function. Therefore, screening of vascular function and cardiac autonomic tone may be advocated in diabetic patients in routine clinics to examine the existence of any comorbid condition, such as diabetic retinopathy, as systemic vascular changes may also affect ophthalmic vasculature.

Neuro-estimator based GMC control of a batch reactive distillation.

In this paper, an artificial neural network (ANN)-based nonlinear control algorithm is proposed for a simulated batch reactive distillation (RD) column. In the homogeneously catalyzed reactive process, an esterification reaction takes place for the production of ethyl acetate. The fundamental model has been derived incorporating the reaction term in the model structure of the nonreactive distillation process. The process operation is simulated at the startup phase under total reflux conditions. The open-loop process dynamics is also addressed running the batch process at the production phase under partial reflux conditions. In this study, a neuro-estimator based generic model controller (GMC), which consists of an ANN-based state predictor and the GMC law, has been synthesized. Finally, this proposed control law has been tested on the representative batch reactive distillation comparing with a gain-scheduled proportional integral (GSPI) controller and with its ideal performance (ideal GMC).

Human T lymphotrophic virus-I (HTLV-I) infection in patients with unclassifiable dermatitis in central Kerala, south India: a preliminary study.

OBJECTIVE: We have conducted a preliminary serostudy to confirm the presence of this virus in cases of dermatitis of unknown aetiology and among individuals with sexually transmitted infections (STI) in central Kerala. METHODS: 45 consecutive patients who attended the dermatology clinic of Medical College Kottayam with extensive dermatitis that could not be clinically classified into any known clinical entity and 37 consecutive patients who presented to the sexually transmitted disease (STD) clinic were enrolled for the study. Serum/plasma samples were screened for anti-HTLV-I antibody. Reactive and indeterminate samples were confirmed by an immunoblot. RESULTS: Among 37 STD clinic attendants, none had antibody to HTLV-I while two individuals (4.44%) among the 45 with dermatitis had antibody to HTLV-I. CONCLUSIONS: Our study proves the presence of HTLV-I in a subset of individuals with poorly defined dermatitis in Kerala. Further larger studies are necessary to assess the extent of this problem and its relation to STI in Kerala.

A peptide enzyme linked immunosorbent assay (ELISA) for the detection of human immunodeficiency virus type-2 (HIV-2) antibodies: an evaluation on polymerase chain reaction (PCR) confirmed samples.

BACKGROUND: HIV-1 and HIV-2 infections differ in prognosis, and may also require different prevention and/or treatment approaches. Thus, estimating the true prevalence of HIV-1 and HIV-2 infections, as well as co-infections, is a critical step in controlling the disease. There are a few commercial ELISA and immunoblot kits, which can differentiate between HIV-1 and HIV-2 infections. However, some of these assays overestimate the prevalence of dual infection. Hence, it is necessary to develop assays capable of discriminating between the two infections. OBJECTIVES: To develop a synthetic HIV-2 env based peptide ELISA for the detection of HIV-2 specific antibodies and evaluate its performance on samples from HIV positive individuals previously tested by HIV-1 and HIV-2 PCR and HIV seronegative individuals. STUDY DESIGN: We studied 45 HIV seronegative and 63 HIV infected individuals, including 30 HIV-1 PCR and immunoblot positives, 19 HIV-2 PCR and immunoblot positives, five HIV-1 and two PCR and dual immunoblot positives, two PCR negative but positive for HIV-2 by immunoblot and seven dual immunoblot positives who were only positive for HIV-1 by PCR. RESULTS: All 24 HIV-2 PCR positive samples tested were positive by the peptide assay. Among 30 HIV-1 PCR and immunoblot positive samples, only one (3.3%) showed an absorbance value above the cut off level. The seven dual positive samples by immunoblot (only positive for HIV-1 by PCR) were negative by the HIV-2 peptide ELISA. There was a 100% concordance between HIV-2 PCR and peptide ELISA. The sensitivity, specificity, and the likelihood ratio for the peptide ELISA were 100,94.9, and 19.5, respectively when compared against the PCR findings. CONCLUSIONS: This ELISA, using a specific immunodominant epitope (11 amino acids) from the transmembrane (gp36) portion of the HIV-2 envelope glycoprotein showed a high concordance with PCR findings. This can be considered as a highly sensitive, specific and economically feasible assay for the discrimination of HIV-1 and HIV-2, and may serve as an alternative to HIV-2 PCR in epidemiological studies.

A pilot study of HTLV-I infection in high-risk individuals & their family members from India.

BACKGROUND & OBJECTIVES: Human T lymphotropic virus-I (HTLV-I) has been associated with adult T cell lymphoma/leukemia (ATLL). There are Indian studies on HTLV-I infection among people with sexually transmitted infection, but no large study has been conducted on individuals with haematological malignancies. In this group of individuals, serology is known to under-diagnose HTLV-I infection. This study was carried out to identify serologically and where possible with molecular techniques, HTLV-I infection in individuals with haematological malignancies. To understand the modes of transmission, family members of individuals with proven HTLV-I infection were also studied. Individuals with sexually transmitted infection (STI), blood donors and pregnant women were also studied. METHODS: Particle agglutination test was used to detect antibody to HTLV-I. HTLV genome was amplified by polymerase chain reaction (PCR) and detected with probes by digoxiginin (Dig) ELISA. RESULTS: There was no serological evidence of HTLV-I infection among the healthy blood donors and pregnant women studied. High prevalence of anti-HTLV-I antibody was identified in the patients with haematological malignancies (8 of 86 patients, 9.3%) and a lower prevalence in individuals with STI (8 of 670 individuals, 1.2%). In the STI group, all 8 individuals seroreactive to HTLV-I were coinfected with human immunodeficiency virus (HIV). In the group with haematological malignancies, three of 22 (13.6%) patients with leukemia, 3 of 11 (27.3%) with cutaneous T-cell lymphoma (CTCL) and 2 of 53 (3.8%) with lymphoma were reactive for anti-HTLV-I antibody. In this group, PCR identified all the seroreactive individuals tested. There were also seronegative infected individuals who were only identified by PCR. There was also a large number of seronegative family members who were only positive by PCR. INTERPRETATION & CONCLUSION: The study revealed a strong disease association of HTLV-I with haematological malignancies and evidence for both horizontal and vertical transmission of the infection in the Indian population. HTLV-I infection appears to be common among family members of individuals with HTLV-I associated haematological malignancies.

Molecular confirmation of human immunodeficiency virus (HIV) type 2 in HIV-seropositive subjects in south India.

Nested PCRs for human immunodeficiency virus type 1 (HIV-1) and HIV-2 were compared with immunoblot test results. Twelve of 13 immunoblot-positive HIV-2 samples were positive by PCR. There were five INNO-LIA (Innogenetics, Zwijnaarde, Belgium) and/or HIVBLOT 2.2 (Genelabs, Singapore) samples that tested positive for dual infection. HIV-1 PCR was positive in all samples, while HIV-2 PCR was positive in two and RIBA (Chiron Corporation, San Diego, Calif.) was positive for HIV-2 in three samples. Thus the prevalence of HIV-2 is accurately estimated by the use of immunoblotting, but that of HIV-1 and -2 dual infection may be overestimated.

Peripheral CD4+/CD8+ T-lymphocyte counts estimated by an immunocapture method in the normal healthy south Indian adults and HIV seropositive individuals.

BACKGROUND: Flow cytometry is the standard method for the estimation of CD4/CD8 counts, but the high initial investment for this instrument and costly reagents make it unaffordable to most of the centers in a developing country like India. OBJECTIVES: To evaluate the feasibility of an alternate system for the estimation of CD4 and CD8 counts in normal south Indian adults and validate the usefulness of this assay to monitor the counts in HIV seropositive individuals. STUDY DESIGN: Forty-six normal healthy adults and 68 HIV seropositive individuals both belonging to south Indian linguistic groups were enrolled in this cross-sectional study. The HIV seropositive individuals included 54 HIV-1, 9 HIV-2 and 5 HIV 1&2 infected individuals serologically confirmed by one of the commercial Immunoblot kits. The Capcellia CD4/CD8 whole blood assay, an immuno-capture ELISA based kit from Sanofi DIAGNOSTICS Pasteur, (France) was used with a few modifications in the procedure to measure the CD4 and CD8 counts. RESULTS: The mean CD4 cell counts were 1048 (central 95 centile only), 746 and 424 for the normal healthy adults, asymptomatic HIV seropositives and symptomatic HIV patients, respectively, and the mean CD8 counts were 595, 889 and 732, respectively. Statistically significant differences were observed in the CD4 cell counts between HIV seronegative healthy adults and asymptomatic (P < 0.001) as well as asymptomatic and symptomatic (P < 0.05) HIV infected individuals. The mean CD4 counts of asymptomatic HIV-2 infected individuals was significantly higher than the counts of asymptomatic HIV-1 infected individuals (P < 0.05). CONCLUSIONS: This is an user friendly test and can be an alternate to flow cytometry for the estimation of peripheral T-lymphocyte subsets in developing countries. The assay system has certain limitations inherent to ELISA techniques.