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Biomedical subjects

L Agrawal

Publications and source records attributed to L Agrawal.

9 recordsLinked to original sources

Antioxidant enzyme gene delivery to protect from HIV-1 gp120-induced neuronal apoptosis.

Human immunodeficiency virus-1 (HIV-1) infection in the central nervous system (CNS) may lead to neuronal loss and progressively deteriorating CNS function: HIV-1 gene products, especially gp120, induce free radical-mediated apoptosis. Reactive oxygen species (ROS), are among the potential mediators of these effects. Neurons readily form ROS after gp120 exposure, and so might be protected from ROS-mediated injury by antioxidant enzymes such as Cu/Zn-superoxide dismutase (SOD1) and/or glutathione peroxidase (GPx1). Both enzymes detoxify oxygen free radicals. As they are highly efficient gene delivery vehicles for neurons, recombinant SV40-derived vectors were used for these studies. Cultured mature neurons derived from NT2 cells and primary fetal neurons were transduced with rSV40 vectors carrying human SOD1 and/or GPx1 cDNAs, then exposed to gp120. Apoptosis was measured by terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay. Transduction efficiency of both neuron populations was >95%, as assayed by immunostaining. Transgene expression was also ascertained by Western blotting and direct assays of enzyme activity. Gp120 induced apoptosis in a high percentage of unprotected NT2-N. Transduction with SV(SOD1) and SV(GPx1) before gp120 challenge reduced neuronal apoptosis by >90%. Even greater protection was seen in cells treated with both vectors in sequence. Given singly or in combination, they protect neuronal cells from HIV-1-gp120 induced apoptosis. We tested whether rSV40 s can deliver antioxidant enzymes to the CNS in vivo: intracerebral injection of SV(SOD1) or SV(GPx1) into the caudate putamen of rat brain yielded excellent transgene expression in neurons. In vivo transduction using SV(SOD1) also protected neurons from subsequent gp120-induced apoptosis after injection of both into the caudate putamen of rat brain. Thus, SOD1 and GPx1 can be delivered by SV40 vectors in vitro or in vivo. This approach may merit consideration for therapies in HIV-1-induced encephalopathy.

Animals↗

Respiratory function in childhood following repair of oesophageal atresia and tracheoesophageal fistula.

AIM: To determine the relation between respiratory function in infancy and at school age in children who have undergone oesophageal atresia and tracheoesophageal fistula repair, and assess the value of infant respiratory function testing; and to examine the effect of bronchodilators. METHOD: Fourteen children (6 girls, and 8 boys) who had undergone respiratory function testing in infancy were retested at school age (7-12 years). Measurements included lung volume, airways resistance, peak flow, and spirometry. Clinical problems were investigated by questionnaire. Twelve children had repeat measurements after taking salbutamol. RESULTS: Predominant complaints were non-productive cough and dysphagia, but even those children with major problems in infancy reported few restrictions at school or in sport or social activities. Respiratory function and clinical findings at school age appeared unrelated to status in infancy, such that even the patients with severe tracheomalacia requiring aortopexy did not have lung function testing suggestive of malacia at school age. Most patients showed a restrictive pattern of lung volume which would appear to result from reduced lung growth after surgery rather than being a concomitant feature of the primary congenital abnormality. Although six children reported wheeze and four had a diagnosis of asthma, only one responded to salbutamol. This suggests that a tendency to attribute all lower respiratory symptoms to asthma may have led to an overdiagnosis of this condition in this patient group. CONCLUSION: Respiratory function testing in infancy is of limited value in medium term prognosis, but may aid management of contemporary clinical signs. In children respiratory function testing is valuable in assessing suspected asthma and effects of bronchodilators.

Albuterol↗

The role of gonadectomy and testosterone replacement on thymic luteinizing hormone-releasing hormone production.

We and others have identified luteinizing hormone-releasing hormone (LHRH) in cells of the immune system in both animals and humans. LHRH is an immunostimulant, and testosterone is an immunosuppressant. Because testosterone is known to modulate the concentrations of hypothalamic LHRH, we wondered whether testosterone might also alter the concentrations of rat thymic LHRH. Two weeks after castration or sham castration, adult male rats were implanted with either vehicle or testosterone capsules. All animals were killed 4 days after capsule implantation. Thymic LHRH concentration increased significantly in castrated animals. Testosterone replacement prevented this increase. The concentration of the LHRH precursor, proLHRH, decreased significantly, but testosterone replacement prevented this decrease. Steady-state concentrations of LHRH mRNA were not changed by castration or by hormonal replacement. In contrast to the post-castration increase in thymic LHRH, LHRH content of the hypothalamus decreased significantly. Whereas concentrations of LHRH were lower in the thymus than in the hypothalamus, proLHRH concentrations were much greater in the thymus. These data suggest that gonadal manipulation modulates LHRH molecular processing and its tissue concentration in the thymus in addition to those in the hypothalamus, and that the regulation of LHRH molecular processing by testosterone in the hypothalamus is different from that in the thymus.

Analysis of Variance↗

Ethnic differences in the glycemic response to exogenous insulin treatment in the Veterans Affairs Cooperative Study in Type 2 Diabetes Mellitus (VA CSDM).

OBJECTIVE: The Veterans Affairs Cooperative Study in Type 2 Diabetes Mellitus was conducted in NIDDM patients to determine if a significant difference in HbA1c could be achieved between groups receiving standard and intensive treatment. We observed differences in the response to exogenous insulin between African-Americans and other intensively treated patients. Therefore, we assessed the variations of response and correlated factors that might explain such differences. RESEARCH DESIGN AND METHODS: One hundred fifty-three men aged 40-69 years with NIDDM for < or = 15 years were randomized to either the standard therapy (n = 78) or the intensive therapy (n = 75) arm. Of the 75 patients in the intensive therapy group, 57 completed the study on insulin therapy alone. Of these, 18 were African-Americans and 39 were non-African-Americans. We conducted an analysis of the data collected to determine differences in baseline characteristics, glycemic response, insulin requirement, body weight, exercise, and basal C-peptide level, factors that may explain a difference in response to insulin therapy. RESULTS: Glycemic control improved in all patients with intensive insulin therapy. African-Americans achieved a greater improvement in HbA1c compared with non-African-Americans with a similar increment in insulin. This difference could not be explained by differences in body weight, activity, concomitant use of other medicines, or insulin-secretory capacity of the pancreas. CONCLUSIONS: We conclude that ethnic differences may exist in the response to insulin therapy. A knowledge of such differences may aid in achieving good glycemic control, especially since minorities have a greater prevalence of and burden from the microvascular complications of diabetes.

Adult↗

Comparison of morning or bedtime insulin with and without glyburide in secondary sulfonylurea failure.

OBJECTIVES: New treatment options are needed for glycemic control in NIDDM. We evaluated the effects of bedtime or morning insulin treatment, combined with daytime glyburide or given alone. RESEARCH DESIGN AND METHODS: Twenty-nine male patients with NIDDM, mean age 63 +/- 1.7 yr, body weight 124 +/- 2.98% of DBW, received a maximum glyburide dose (20 mg/day) for a minimum of 6 wk, to confirm sulfonylurea failure. Human lente insulin was added for 12 wk either AM (n = 14) or HS (n = 15) and adjusted to obtain fasting euglycemia (FPG; combination treatment phase). Glyburide was then stopped, and insulin was continued for 6 wk, aiming for normal FPG (insulin phase). RESULTS: After combination treatment phase, FPG decreased (P < 0.02) from 12.43 +/- 0.68 to 5.73 +/- 0.65 mM (AM) and from 12.68 +/- 0.76 to 5.51 +/- 0.48 mM (HS) (AM vs. HS, NS). Postbreakfast, presupper, and 0200 AM plasma glucose levels fell equally (P < 0.02) except for 1-h postprandial (AM 12.46 +/- 0.51 mM, HS 10.88 +/- 0.62 mM, AM vs. HS, P < 0.1). Mean HBA1c fell similarly in both AM and HS groups. At 2 wk of the insulin phase, FPG was higher in AM than HS, 9.8 +/- 0.76 vs. 7.56 +/- 0.7 mM (P < 0.1). At the end of insulin phase, plasma glucose levels were similar to the end of combination treatment phase, but the insulin dose had to be raised in AM by 39% (P < 0.02) and HS by 30% (P < 0.05). After the combination treatment phase, fasting C-peptide was significantly suppressed in HS group only, from 1.22 +/- 0.12 to 0.82 +/- 0.09 nM (P < 0.02). At the end of insulin phase, fasting C-peptide was further suppressed in both groups, but 2-h postprandial C-peptide levels decreased significantly in AM group only, from 1.85 +/- 0.23 to 1.42 +/- 0.13 nM (P < 0.02). Triglycerides and total and HDL cholesterol did not change significantly after either combination treatment phase or insulin phase. Mean weight gain was 6.5 lb during combination treatment phase (NS from baseline), without further change during insulin phase. Hypoglycemic reactions, all mild, were recorded at a rate of 1.35/patient in the AM group and 0.4/patient in the HS group (P < 0.025). CONCLUSIONS: Normal fasting glycemia and near-normal postprandial glucose profile could be obtained with combination therapy in NIDDM. Results were similar if insulin, alone or in combination with glyburide, was given before breakfast or at bedtime, but hypoglycemic reactions were more common with conventional morning insulin injections.

Adult↗

Isolation of Legionella pneumophila from patients of respiratory tract disease & environmental samples.

In this preliminary study 45 patients suffering from pneumonia were screened for L. pneumophila. Also 17 random environmental samples viz., water from cooling system used for air-conditioning units and samples from respirator-humidifier were screened. Four of 45 (9%) clinical specimens and 13 of 17 (76%) environmental samples showed presence of L. pneumophila. This is the first report from India of the isolation on L. pneumophila.

Air Conditioning↗

Polyostotic osteonecrosis in a patient with celiac disease.

OBJECTIVE: To emphasize the role of history and physical examination in the clinical evaluation of hypocalcemia and to describe a patient with celiac sprue and multiple osteonecrosis, a previously unrecognized association. METHODS: A case report is presented of a 39-year-old man with mild hypocalcemia, diarrhea, and arthralgias, and the appropriate clinical and laboratory assessment for these complaints is outlined. RESULTS: Secondary hyperparathyroidism, celiac sprue, and extensive osteonecrosis were detected by hematologic and radiologic studies. The hematologic variables normalized after institution of a gluten-free diet and calcium supplementation. CONCLUSION: This is the first report of celiac sprue and osteonecrosis in one patient. A possible causal relationship due to secondary hyperparathyroidism is suggested, and alternative explanations are discussed.

Journal Article↗

Thyrotoxic hypokalemic periodic paralysis: six cases in non-Asian patients.

OBJECTIVE: To describe six cases of thyrotoxic hypokalemic periodic paralysis (THPP) in non-Asian men. METHODS: We present six cases of THPP, including clinical and laboratory findings, treatment, and outcome, and review the related literature. RESULTS: Hypokalemic periodic paralysis is a relatively common occurrence in Asian men with thyrotoxicosis; however, it is unusual in non-Asian patients with thyrotoxicosis. Among our six patients--four Caucasians, one African-American, and one Hispanic--the precipitating factors, initial manifestations, and clinical course varied. In general, treatment with 131 I or potassium eliminated the paralytic episodes. CONCLUSION: THPP needs to be distinguished from nonthyrotoxic hypokalemic periodic paralysis. Although THPP is unusual in non-Asian men, it must be recognized because of the severe and potentially fatal complications, which are reversible with potassium replacement and antithyroid therapy.

Journal Article↗