PubMed Health⌕ Search

Biomedical subjects

A K Gulati

Publications and source records attributed to A K Gulati.

At least 19 recordsLinked to original sources
PubMed2006

Diarrhea, CD4 counts and enteric infections in a hospital - based cohort of HIV-infected patients around Varanasi, India.

BACKGROUND: As most of the studies in HIV patients with diarrhea were cross sectional, focusing on the etiological agents, we are reporting data on the rate of diarrhea, associations between diarrhea and CD4 counts and variation in frequency of identifying a pathogen with consistency of diarrhea and duration in a prospective hospital based study. METHODS: Stool specimens were obtained between Jan 2001 and April 2003 from HIV infected adults with diarrhea presenting to Infectious Disease clinic, Banaras Hindu University, Varanasi. In all patients with diarrhea, specimens were examined by microscopy and cultures to identify pathogens. RESULTS: During the study, 630 person years of observations with diarrhea were analyzed. 140 stool samples were collected representing 43% of episodes of reported diarrhea. Positivity of finding a pathogen from watery stools and formed stools were 40%&24% respectively (p < 0.01) probably due to associated inflammation is more in watery diarrhea. Patients having chronic diarrhea are 2.25 (95%CI 1.52-2.81) times at more risk of developing other opportunistic infections compared to those who don't have. However this is not true with the acute diarrhea where risk of harboring the opportunistic infections remain same. CONCLUSION: Diarrhea was most strongly associated with low CD4 counts. Over two-thirds of diarrheal episodes were undiagnosed, suggesting that unidentified agents or primary HIV enteropathy are important causes of diarrhea in this population. There is a strong negative association between duration of diarrhea and CD4 levels.

AIDS-Related Opportunistic Infections↗
PubMed2001

Prevalence of HIV among low and high risk population of eastern part of northern India.

A total of 7,904 persons visiting University Hospital of Banaras Hindu University (BHU), Varanasi, were screened for HIV antibody by ELISA and/or rapid test. The overall seroprevalence of HIV (3.17%) in this area was higher than that of Uttar Pradesh and India as a whole. The seroprevalence of HIV/AIDS among the high risk group (HRG) (6.42%) being significantly higher than low risk group (LRG) (0.37%). In the LRG, the prevalence among medical and surgical patients; and ANC (antenatal cases) was 1.17% and 0.14%, respectively. However, HIV infection was not detected in HCWs (healthcare workers), BHU students and foreigners. Among HRG, CSWs (commercial sex workers) had the highest prevalence (14.0%) and STD (sexually transmitted diseases) patients, the lowest prevalence (1.99%). The STD patients had significantly lower prevalence rate as compared to others in HRG. Majority of the HIV positive were found to be within the age group 15-44 years, with heterosexual mode as the main route of transmission. Seven HIV positive children were of 2-5 yr old age group. Majority of seropositive women (62.52%) were working in a low income jobs and were mainly infected by their spouses who was mostly migrating labourers of lower socioeconomic group and with less than primary level of education. Married females, being mainly the spouses of HIV positive males had the highest seropositivity (60.25%). These population people were directly transmitting the infection from the metropolitan cities to the rural areas of this region. Prevalence of HIV-2 was negligible as compared to HIV-1, the actual reason is yet to be explored.

Adolescent↗
PubMed2000

Prevalence of human immunodeficiency virus infection in and around Varanasi, Uttar Pradesh, India.

Human Immunodeficiency Virus (HIV) infection is rising rapidly in the eastern Uttar Pradesh; however no data is available regarding its positivity rate. We have screened 1239 cases of various groups. HIV seropositivity rate of 0.28% was noted. These results suggest that HIV infection is spreading rapidly in this part of the country. M. tuberculosis was the commonest co-infection amongst them (29.5%). We recommend routine HIV screening of all patients of tuberculosis, especially if the persons frequent the cities, visit foreign countries where sex tourism is encouraged or stay away from their spouses for long periods as true history of sexual contact with commercial sex workers was difficult to obtain from them.

Adult↗
PubMed1999

Expression of phosphatidylinositol 3-kinase during EGF-stimulated wound repair in rabbit corneal epithelium.

PURPOSE: To investigate the effect of epidermal growth factor (EGF) on the induction of phosphatidylinositol 3-kinase (PI 3- kinase) gene expression during rabbit corneal epithelial wound repair. METHODS: Epithelial wounds (6 mm in size) were created in rabbit corneas and EGF (2 microg) applied every 8 hours to one eye, and the other eye served as a control. The wound repair was monitored by staining the tissue with fluorescein followed by photography. The wound area was quantified with a computer program. At different time intervals, the rabbits were killed and the corneal epithelium used for estimation of PI 3-kinase activity, western blot analysis, or reverse transcription-polymerase chain reaction (RT-PCR). For in situ hybridization, the whole corneas were sectioned and the sections processed with PI 3-kinase mRNA probes. RESULTS: In the untreated eye, the epithelial wound progressively healed in a time-dependent manner, with 75% of the wound closed at 48 hours post wounding. Application of EGF to the corneal epithelium further stimulated wound repair at all time intervals, and the wound was completely closed at 48 hours. Analysis of PI 3-kinase showed a time-dependent increase in its enzyme activity that was maximally increased at 36 hours, the time when the wound was nearly closed. Western blot analysis revealed increased amounts of PI 3- kinase protein during the course of wound repair. Analysis of RT-PCR products from epithelial tissues, taken at different times during wound repair, showed increased PI 3-kinase expression that was maximum at 48 hours post wounding. A visible increase in PI 3-kinase gene expression was also detected by in situ hybridization during the course of the wound repair. This expression was increased maximally by EGF at 48 hours post wounding. CONCLUSIONS: The results indicate a temporal correlation between increased activation and expression of PI 3- kinase and the epithelial wound repair. Topical application of EGF further stimulates the activity and expression of PI 3- kinase. It is suggested that PI 3- kinase and its products may play a role in EGF-induced cell proliferation during corneal epithelial wound repair.

Animals↗
PubMed1999

HIV infection in Varanasi.

A total of 6038 serum samples collected from individuals staying/residing in the eastern part of northern India, were screened for antibodies against HIV. The screening was done by ELISA and followed by confirmation of reactive samples by Western Blot. The seropositivity was detected in 154 (2.6%) persons. The prevalence amongst high risk groups was 68/1000 while it was 2.8/1000 in low risk population. The male to female ratio was 1.8:1 in seropositives. Increase by more than three folds in the prevalence was observed from 1994 (1.5%) to 1997 (5.0%). About 50% of the seropositives were in their third decade of life. Seropositives were predominantly (> 90%) from eastern Uttar Pradesh. Almost all the cases could be linked to Mumbai, one of the largest commercial and industrial centres of India.

Adult↗
PubMed1999

Herpes simplex virus-1 encephalitis in eastern Uttar Pradesh.

OBJECTIVE: To study the proportion of HSV-1 encephalitis in acute viral encephalitis. METHODS: One hundred and five patients presenting with clinical diagnosis of acute viral encephalitis and with exclusion of other possible causes of acute inflammatory brain disease prevalent in the area by relevant laboratory investigations were included in the study. Ninety single CSF samples were tested for HSV-1 IgM antibodies by ELISA test supplied by Dia Medix Corporation, USA. CT Scan and EEG studies were carried out in 25 patients. RESULTS: Clinical and neuro investigational profile of patients suggested a low incidence of HSV-1 encephalitis in the study group. IgM antibodies were present in CSF sample of one patient only. CONCLUSION: HSV-1 encephalitis constitutes a very low proportion (1.1%) of acute viral encephalitis cases seen in Eastern Uttar Pradesh (India).

Encephalitis, Herpes Simplex↗
PubMed1998

The use of resin-bonded porcelain crowns for primary molars in infra-occlusion.

Infra-occluded primary molars without permanent successors may require restorative treatment to maintain occlusal stability and periodontal health in addition to creating an aesthetic result. This paper describes the use of two resin-bonded porcelain crowns to provide a simple, minimally invasive technique using a material with good wear resistance and high strength to create an aesthetic and functional occlusion.

Adolescent↗
PubMed1998

Immune response and neurotrophic factor interactions in peripheral nerve transplants.

Several types of immunocompetent cells of hematopoietic origin are involved in determining the immunological and regenerative fate of peripheral nerve transplants used for neurosurgical repair. The present study compares the immunological fate of nerve isografts and allografts with emphasis on the immunobiological events and neurotrophic interactions leading to graft survival and nerve fiber regeneration through them. The nerve transplantation model is unique as tissue rejection/inflammation is observed along with the nerve regeneration process. Nerve grafts become vascularized within a few days via neovascularization after transplantation. This is followed by progressive invasion of host macrophages and T lymphocytes that recognize the histocompatible antigens and initiate the rejection response. Two main types of donor resident cells are involved in early stages of graft rejection. These are macrophages and Schwann cells. Both of these cells have been found to possess antigen-presenting function and also can produce several cytokines. The most relevant to the peripheral nerves are tumor necrosis factor (TNF-alpha), interleukin-1 (IL-1), interferon-gamma (IFN-gamma) and IL-12. TNF-alpha in addition to its capacity to kill cells is involved in activation of macrophages. IL-12 and IFN-gamma have a potential role in modulating and enhancing of the immune response. Finally, IL-1 is of special significance because it promotes the expression of nerve growth factor (NGF) by the Schwann cells of the peripheral nerve and is important for nerve fiber regeneration. NGF in turn has been shown to enhance macrophage function and inflammatory response. Taken together, these findings show that NGF levels and inflammation in injured tissue play an important role in determining the success of transplants and in tissue repair.

Animals↗
PubMed1996

Peripheral nerve regeneration through short- and long-term degenerated nerve transplants.

The present study was designed to compare regenerative potential of normal and degenerated nerve grafts. Peripheral nerves in rats were induced to undergo in situ degeneration for a period of 6 weeks, 3, 6 and 12 months. During early phase of denervation the myelin and axons degenerated and were absorbed. With prolonged denervation (i.e. 12 months), such nerves were reduced in size and exhibited extensive fibrosis. A 2 cm long segment of the degenerated nerve was transplanted in an surgically created gap in the host peroneal nerve to evaluate their regeneration supporting ability. Regeneration of host axons occurred rapidly through nerves degenerated for a period up to 3 months. The extent of regeneration was compromised in 6-month degenerated nerve group, and was significantly reduced in the 12-month degenerated nerve grafts. These results show that with extended degeneration interval, the regeneration supporting ability of nerves is compromised. It is concluded that nerve repair should not be excessively delayed in order to compromise recovery.

Animals↗
PubMed1995

The influence of cultured Schwann cells on regeneration through acellular basal lamina grafts.

Acellular basal lamina grafts have been shown to be less immunogenic in comparison to cellular grafts, but possess a limited potential for supporting axonal regeneration through them. The present study describes the effect of cultured Schwann cells on enhancing regeneration through acellular grafts. 2 cm long acellular grafts, and in vitro Schwann cell populated acellular grafts were used to repair a surgically created gap in the host peroneal nerve. The transplants were analyzed at 1, 2, 4 and 8 weeks to determine their ability to support axonal regeneration. Host axonal regeneration through Schwann cell cocultured acellular grafts occurred rapidly and was significantly better as compared to non-cultured acellular grafts. The results demonstrate a beneficial effect of Schwann cell culture pretreatment on regeneration through acellular grafts and an improved recovery of the target muscle. The procedure of first preparing acellular grafts with subsequent coculture with Schwann cells offers a novel approach for the repair of injured nervous tissue.

Animals↗
PubMed1995

Immunological fate of Schwann cell-populated acellular basal lamina nerve allografts.

Acellular basal lamina allografts are known to exhibit reduced immunogenicity, but the extent of host axonal regeneration through such grafts is reduced in comparison to the cellular isografts. The present study was designed to determine both the ability of cultured Schwann cells to populate acellular allografts, and the effects of Schwann cells on immunogenicity and regenerative potential. Isogeneic and allogeneic Schwann cell-populated acellular allografts of 2.0 cm length were used to repair a surgically created gap in the host rat peroneal nerve. Transplanted nerves were analyzed at 1, 2, 4, and 8 weeks later to determine their fate and ability to support axonal regeneration. Acellular allografts cocultured with isogeneic Schwann cells survived and supported axonal regeneration through them. In contrast, acellular allografts cocultured with allogeneic Schwann cells underwent rejection and were unsuccessful. The results show that cultured Schwann cells continue to exhibit immunogenicity and are a critical factor in allograft survival. It is thus important to use host-matched (isogeneic or autologous) Schwann cells to populate acellular basal lamina grafts in order to enhance their axonal growth-supporting function.

Animals↗
PubMed1995

Regeneration pattern of cardiac and skeletal muscle after transplantation into a skeletal muscle bed in rats.

BACKGROUND: The ability of skeletal muscle to regenerate after injury is well established. In contrast, cardiac muscle is incapable of regeneration and recovery after injury. The aim of the present study was to evaluate and compare the regeneration pattern of cardiac and skeletal muscle after transplantation into a skeletal muscle bed in rats. METHODS: The following group of transplants were performed at the site prepared by removing the host extensor digitorum longus (EDL) muscle. The first group consisted of cardiac muscle transplanted as one piece or after mincing into 1-mm pieces. The second group included cotransplants of cardiac and skeletal muscle minces that were intermixed. Entire EDL muscle or minced EDL muscle were also transplanted for comparison. Rats were sacrificed 3-30 days after transplantation for morphological analysis. RESULTS: The results demonstrated that skeletal muscle transplants underwent rapid regeneration, and by 30 days the entire muscle was filled with regenerated myofibers. In transplants of cardiac muscle significant inflammation, myocardial degeneration and necrosis were observed. In spite of the necrosis and fibrosis, the presence of a few regenerated myotubes in the outer region was observed. In cardiac and skeletal muscle cotransplants, the inflammation was restricted to cardiac tissue; however, by 30 days the entire cotransplant was filled with regenerated myotubes and myofibers. CONCLUSIONS: These results show that skeletal muscle is capable of growth, regeneration, and integration with the cardiac muscle after cotransplantation. Combination of skeletal and cardiac muscle may prove useful in defining the cellular processes necessary for enhancing cardiac repair after injury.

Animals↗
PubMed1994

Immunogenicity and regenerative potential of acellular nerve allografts to repair peripheral nerve in rats and rabbits.

This study describes the ability of acellular nerve allografts (genetically different) to repair injured peripheral nerve in rats and rabbits. We recently reported the regeneration supporting potential and immunogenicity of acellular nerve allografts in rats. The present study extends our previous work and quantitates the extent of axonal regeneration through various nerve grafts in rats. In addition, the use of longer nerve grafts to repair rabbit peripheral nerve is described. Inbred strains of Fischer and Buffalo rats and New Zealand white and Dutch rabbits were used. Acellular grafts were prepared by repeated freezing and thawing of in situ degenerated nerves. Non-frozen predegenerated nerves were used as cellular grafts for comparison. Nerve isografts (genetically identical) were also performed. The graft length was 2.0 cm in rats and 4.0 cm in rabbits. In both rats and rabbits the cellular isografts showed the most rapid regeneration and target muscle innervation. The cellular allografts were invariably rejected and only showed limited regeneration. In contrast, acellular allografts, in spite of their mild immunogenicity, allowed significant regeneration through them. It is concluded that acellular nerve allografts are capable of supporting axonal regeneration because of their reduced immunogenicity, and thus can be used to bridge nerve gaps after nerve injury.

Animals↗
PubMed1994

Toxic neurofilamentous axonopathies and fast axonal transport. V. Reduced bidirectional vesicle transport in cultured neurons by acrylamide and glycidamide.

Fast axonal transport deficiencies as mechanisms of action of acrylamide in producing axonal degeneration are under evaluation. The current study determines the effects of acrylamide and several analogues on the number of vesicles moving within the neurite processes of cultured rat embryonic neurons. Acrylamide produced severe, concentration-dependent (0.25-1.0 mM) and time-dependent (0-60 min) reduction in the quantity of vesicles translocated in both the anterograde and retrograde directions. Glycidamide, a potential neurotoxic metabolite of acrylamide, produced a time-dependent but not a concentration-dependent (in the 0.25-1.0 mM range) reduction in bidirectional transport. Based on inhibition at 60 min, glycidamide was estimated to be 4 times more potent than acrylamide in altering transport. Propionamide, a C1-C2 saturated nonneurotoxic acrylamide analogue, had no effect on axonal transport. While a tendency for methylene bisacrylamide (MbACR) to reduce vesicle transport was noted, at the concentration used no statistically significant differences from control were observed. The data support the correlation between toxicant-induced fast anterograde and retrograde axonal transport reductions and axonal degeneration produced by acrylamide and its analogues.

Acrylamide↗
PubMed1994

Chlamydial serology and laparoscopic findings in infertile women.

Fifty-seven infertile women were studied for presence of chlamydial infection by detecting antichlamydial antibodies using indirect immunoperoxidase assay technique. Laparoscopy was performed in all of them. Inflammatory changes in fallopian tubes were present irrespective of serological status. Thus no rigid criteria for carrying out laparoscopy can be made. A high index of suspicion is required for detection of chlamydial infection as it runs an indolent course with no specific symptoms.

Antibodies, Bacterial↗