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Biomedical subjects

H Singh

Publications and source records attributed to H Singh.

At least 361 records · Page 20Linked to original sources
PubMed1988

Isolation, purification and quantification of phenolic glycolipid-1 from human leprosy skin tissues.

Phenolic glycolipid-I, a marker lipid of Mycobacterium leprae, was isolated from skin biopsies obtained from untreated lepromatous leprosy patients by silicic acid and florisil column chromatography and purified by thin layer chromatography. Tissues with varying bacillary loads were analysed for their phenolic glycolipid content. A good correlation was observed between the bacillary population of the tissues and the phenolic glycolipid content.

Antigens, Bacterial↗
PubMed1988

Stability of oral polio vaccine at different temperatures.

The stability of five batches of oral polio vaccine stored at -20, 4-8, 22 and 36 degrees C for 7, 14 and 21 days was studied. The virus titrations were performed by the standard macro-method. There was little loss in virus titre when samples were kept at -20 and 4-8 degrees C for 21 days, whereas the samples exposed to 36 degrees C for 21 days showed almost complete loss in virus titre. The average loss in virus titre in a year (log TCID50) was 0.47 at -20 degrees C and 0.65 at 4-8 degrees C when various samples were stored at these temperatures. At 22 degrees C the average loss in virus titre after 21 days was about 1.50. The samples subjected to ten cycles of freezing and thawing did not show any loss in virus titre. Likewise there was not much loss in virus titre in three samples stored at 4-8 degrees C for a year. Oral polio vaccine stabilized with magnesium chloride is quite a stable vaccine and maintenance of a proper cold chain is recommended for the delivery of a potent vaccine in countries with high ambient temperature.

Drug Stability↗
PubMed1988

Changes in the population of active rosette-forming cells: a sensitive index for mortality among thermal injury patients.

Peripheral blood lymphocytes from normal and thermally injured patients were studied for their ability to form rosettes with sheep red blood cells (SRBC) by active E-rosette assay at different times postinjury. The population of active rosette forming cells (ARFC) was observed to be significantly lower (P less than 0.001) in thermal injury patients compared with the normal subjects. The age and sex of the patient did not seem to have any significant effect on the ARFC population or the total lymphocyte count. The degree of burn had a significant (P less than 0.05) effect on the ARFC population but not the total lymphocyte count during the first 10 days immediately after burn, with partial skin thickness burn patients having more ARFC compared with full skin thickness burn patients. Further analysis of the data revealed an important correlation between the per cent ARFC in peripheral blood and the survival of the patients. Patients who died from their injuries showed a continuous decline in ARFC over the period of study, whereas the patients who survived showed a gradual increase until the ARFC number returned to within the normal range. The observed differences in the ARFC population between survivors and non-survivors were apparent as early as the first 10 days postinjury. Thus, the percentage of ARFC in the total peripheral blood may be used as an index for the early identification of patients at a greater risk of mortality.

Adolescent↗
PubMed1988

Neuroleptic-induced supersensitivity psychosis: retrospective study of schizophrenic inpatients.

Chouinard has suggested that a significant number of schizophrenic outpatients may rapidly relapse after discontinuing or abruptly reducing antipsychotic drugs, and he has hypothesized that this relapse reflects a supersensitivity psychosis related to mesolimbic postsynaptic dopamine supersensitivity caused by drug therapy. Using Chouinard's criteria, the authors found 12 probable but no definitive cases of this syndrome while conducting a chart review of 265 hospitalized schizophrenic patients. Six of the 12 patients were subsequently rediagnosed as schizoaffective. Four patients had tardive dyskinesia, but this condition did not worsen after the drug dosage was decreased. Although supersensitivity psychosis was not common among this population, further study of the syndrome is needed to determine if neuroleptics are causing a subgroup of patients to relapse early or if the early relapses are a manifestation of the natural course of illness in these patients.

Adult↗
PubMed1988

Tardive dyskinesia rating scales.

The authors review the history of the introduction of the concept of tardive dyskinesia (TD). They discuss the various ranges of prevalence of TD and also of senile dyskinesias and point out that these are two different entities. They critically discuss the use of various rating scales for measuring TD and then review the literature on the use of various other tools used for measuring TD. The issue of practical difficulties and flaws encountered in the assessment of TD is also addressed. Lastly, they suggest that various electromyographic or other gadgetry may very well identify neuromuscular abnormalities at an earlier point in time and this could lead to earlier detection and intervention as well as further the information about pathophysiology of this disorder.

Dyskinesia, Drug-Induced↗
PubMed1988

Nalidixic acid.

Explore the source record for details and available documents.

Female↗
PubMed1988

Intranasal nitroglycerin and intraocular pressure during general anesthesia.

Two separate studies of the effects of nitroglycerin (NTG) on intraocular pressure (IOP) were conducted. In study I, 12 healthy adults received 3 ml NTG solution (2 mg/3 ml) intranasally during steady-state anesthesia. This resulted in a significant decrease in IOP along with decreases in arterial blood pressure and central venous pressure. In study II, 30 patients, classified randomly into two equal groups, received either normal saline (3 ml) or NTG solution (2 mg/3 ml) intranasally, in a double-blind manner, 2 minutes before anesthetic induction with thiopental followed by succinylcholine (1.5 mg/kg). In patients given saline, IOP increased significantly above the preinduction levels after succinylcholine. Tracheal intubation increased it further. In the NTG group, increases in IOP after succinylcholine and after tracheal intubation were significantly less than in the control (saline) group. It is concluded that intranasal administration of NTG decreases IOP in anesthetized patients and, when employed as pretreatment, allows the use of succinylcholine to facilitate tracheal intubation without an increase in IOP above preinduction levels.

Administration, Intranasal↗
PubMed1987

Ceruloplasmin gene expression in human cancer cells.

The copper transport protein, ceruloplasmin, is suggested to have a role in cancer since it is involved in angiogenesis and neovascularization. In order to understand the role of ceruloplasmin in malignant cells, we have recently isolated and sequenced a human ceruloplasmin cDNA clone. In the present study, we have investigated the ceruloplasmin gene expression in human colon and breast cancer cell lines. The poly (A) RNA from human colon (WiDr) and human breast (MCF-7) cancer cell lines was analyzed for the presence of ceruloplasmin mRNA. The Northern blot analysis revealed the presence of a 3.7 kb band of ceruloplasmin mRNA in these cell lines. Dot blot analysis revealed that ceruloplasmin mRNA is at least three fold more abundant in tumor cells as compared to normal rat liver.

Breast Neoplasms↗
PubMed1987

Beta-oxidation of very-long-chain fatty acids and their coenzyme A derivatives by human skin fibroblasts.

The beta-oxidation of lignoceric acid (C24:0), hexacosanoic acid (C26:0), and their coenzyme A derivatives was investigated in human skin fibroblast homogenates. The cofactor requirements for oxidation of lignoceric acid and hexacosanoic acid were identical but were different from their coenzyme A derivatives. For example, lignoceric acid and hexacosanoic acid oxidation was strictly ATP dependent whereas the oxidation of the corresponding coenzyme A derivatives was ATP independent. Also the rate of oxidation of coenzyme A derivatives of lignoceric acid or hexacosanoic acid was much higher compared to the free fatty acids. In patients with Zellweger's syndrome, X-linked adrenoleukodystrophy and infantile Refsum's disease, the beta-oxidation of lignoceric and hexacosanoic acids was defective whereas the oxidation of their corresponding coenzyme A derivatives was nearly normal. The results presented in this communication suggest strongly that the beta-oxidation of very-long-chain fatty acids occurs exclusively in peroxisomes. However, the coenzyme A derivatives of very-long-chain fatty acids can be oxidized in mitochondria as well as in peroxisomes. The inability of the mitochondrial system to oxidize free fatty acids may be due to its inability to convert them to their corresponding coenzyme A derivatives. Our results suggest that a specific very-long-chain fatty acyl CoA synthetase may be required for the activation of the free fatty acids and that this synthetase may be deficient in patients with Zellweger's syndrome and possibly X-linked adrenoleukodystrophy, as well. The results presented suggest that substrate specificity and the subcellular localization of the synthetase may regulate the beta-oxidation of very-long-chain fatty acids in the cell.

Abnormalities, Multiple↗
PubMed1987

Double-blind comparison of lidocaine, tubocurarine and diazepam pretreatment in modifying intraocular pressure increases.

One hundred and sixty patients, divided randomly into four groups received normal saline (5 ml), d-tubocurarine (0.05 mg X kg-1), diazepam (0.1 mg X kg-1) or lidocaine (1 mg X kg-1) as pretreatment, in a double blind manner, five minutes before anaesthetic induction with thiopentone and succinylcholine (1 mg X kg-1). Succinylcholine caused a significant increase in IOP in all groups. However, in the lidocaine group, this increase was significantly less than that observed in the control group. The post-succinylcholine increase in IOP was further aggravated by tracheal intubation in all except the lidocaine group. A further clinical trial with higher doses of lidocaine is suggested to assess its ability to obtund the succinylcholine-induced increase in IOP. Lidocaine in a dose of 1 mg X kg-1 IV prevents the rise in IOP which follows intubation.

Adolescent↗
PubMed1987

Very long chain fatty acid beta-oxidation by rat liver mitochondria and peroxisomes.

Crude mitochondrial fractions were isolated by differential centrifugation of rat liver homogenates. Subfractionation of these fractions on self-generating continuous Percoll gradients resulted in clearcut separation of peroxisomes from mitochondria. Hexacosanoic acid beta-oxidation was present mainly in peroxisomal fractions whereas hexacosanoyl CoA oxidation was present in the mitochondrial as well as in the peroxisomal fractions. The presence of much greater hexacosanoyl CoA synthetase activity in the purified preparations of microsomes and peroxisomes compared to mitochondria, suggests that the synthesis of coenzyme A derivatives of very long chain fatty acids (VLCFA) is limited in mitochondria. We postulate that a specific VLCFA CoA synthetase may be required to effectively convert VLCFA to VLCFA CoA in the cell. This specific synthetase activity is absent from the mitochondrial membrane, but present in the peroxisomal and the microsomal membranes. We postulate that substrate specificity and the subcellular localization of the specific VLCFA CoA synthetase directs and regulates VLCFA oxidation in the cell.

Animals↗
PubMed1987

Very long chain fatty acid beta-oxidation by subcellular fractions of normal and Zellweger syndrome skin fibroblasts.

Very long chain fatty acid (VLCFA) beta-oxidation was compared in homogenates and subcellular fractions of cultured skin fibroblasts from normal individuals and from Zellweger patients who show greatly reduced numbers of peroxisomes in their tissues. beta-Oxidation of lignoceric (C24:0) acid was greatly reduced compared to controls in the homogenates and the subcellular fractions of Zellweger fibroblasts. The specific activity of C24:0 acid beta-oxidation was highest in the crude peroxisomal pellets of control fibroblasts. Fractionation of the crude mitochondrial and the crude peroxisomal pellets on Percoll density gradients revealed that the C24:0 acid oxidation was carried out entirely by peroxisomes, and the peroxisomal beta-oxidation activity was missing in Zellweger fibroblasts. In contrast to the beta-oxidation of C24:0 acid, the beta-oxidation of C24:0 CoA was observed in both mitochondria and peroxisomes. We postulate that a very long chain fatty acyl CoA (VLCFA CoA) synthetase, which is different from long chain fatty acyl CoA synthetase, is required for the effective conversion of C24:0 acid to C24:0 CoA. The VLCFA CoA synthetase appears to be absent from the mitochondrial membrane but present in the peroxisomal membrane.

Abnormalities, Multiple↗
PubMed1987

Antispermatogenic effects of cyclophosphamide in the Syrian hamster.

Cyclophosphamide is an alkylating antineoplastic drug and has been shown to impair spermatogenesis after chronic exposures. The purpose of this investigation was to determine the effect of cyclophosphamide on sperm production in hamsters following subacute intraperitoneal (ip) exposures. The Syrian hamster, Mesocricetus auratus, aged 10-11 wk, received single daily ip doses for 4 d ranging from 10 to 250 mg cyclophosphamide/kg body weight. Control hamsters received an equivalent volume of phosphate-buffered saline solution. Testis weight, caudal sperm number, and sperm morphology were monitored for 12 wk. Cyclophosphamide failed to induce sperm abnormalities. Testis weight and sperm count were slightly suppressed at wk 1 and 4 before returning to normal at wk 12. This study showed that subacute doses of cyclophosphamide in hamsters did not significantly affect the sperm production as previously reported in other animals.

Animals↗
PubMed1987

Elapid snake bite.

Four patients were admitted with respiratory muscle paralysis following an elapid snake bite. Two were treated with antivenine, repeated doses of neostigmine and artificial ventilation; the other two with artificial ventilation only. There was no clinically significant difference in recovery. It is suggested that one should avoid the use of antivenine and neostigmine in the management of elapid snake bite once muscle paralysis has become established.

Adolescent↗