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Biomedical subjects

A Sharma

Publications and source records attributed to A Sharma.

At least 379 records · Page 21Linked to original sources
PubMed1999

Alexander's disease: a case report of a biopsy proven case.

A case of infantile onset Alexander's disease in a two and a half year old male child is presented, who had progressively increasing macrencephaly since birth. A frontal lobe biopsy revealed collections of Rosenthal fibres in the subpial and perivascular areas with diffuse dysmyelination and presence of reactive astrocytes. The Rosenthal fibres were immunoreactive for glial fibrillary acidic protein and ubiquitin. Electron microscopic examination showed the Rosenthal fibres as intra-astrocytic and extracellular granular osmiphilic collections.

Age of Onset↗
PubMed1999

Apical bridging in association with regular root formation following single-visit apexification: a case report.

A case report is presented in which continuing root formation occurred in a carious nonvital and immature mandibular second premolar after single-visit calcium hydroxide apexification treatment. An apical hard tissue barrier was formed, accompanied by a separate, mesioapically growing root, 7 months posttreatment. Treatment was concluded with gutta-percha root canal restoration. The success of this single-visit apexification treatment supports the contention that frequent changing of the calcium hydroxide dressing is not always required to induce apical closure.

Calcium Hydroxide↗
PubMed1999

Inhibitory effect of piceatannol, a protein tyrosine kinase inhibitor, on asexual maturation of Plasmodium falciparum.

This report describes the effect of piceatannol (3,4,3',5'-tetrahydroxy trans stilbene), a plant secondary natural product, on protein tyrosine kinase (PTK) activity in different stages of P. falciparum grown in vitro. Piceatannol inhibited PTK activity in trophozoites and schizonts suggesting that PTK may be important in the initial asexual maturation of the parasite. Inhibition of PTK activity by piceatannol may thus provide new insights into more specific tools for chemotherapeutic interventions for P. falciparum.

Animals↗
PubMed1999

An evaluation of oxidative stress in diabetes mellitus during uncontrolled and controlled state and after vitamin E supplementation.

OBJECTIVE: The study was conducted on 50 patients (10 insulin dependent diabetes mellitus (IDDM) and 40 non-insulin dependent diabetes mellitus (NIDDM) of recently diagnosed diabetes mellitus. The main objectives of the study were: 1. To evaluate oxidative stress at uncontrolled stage. 2. To evaluate the effect of optimal control on oxidative stress irrespective of type of drug therapy used. 3. To further evaluate the effect of vitamin E supplementation on oxidative stress after achieving optimal control. This was done in order to explore anti-oxidant effect of vitamin E. METHODS: Fifty patients of uncontrolled diabetes of less than 1 year duration and without any overt complications were studied. The parameters of oxidative stress included malonyl-di-aldehyde (MDA), reduced glutathione and vitamin E levels in the blood. They were done at three stages i.e. (a) In uncontrolled stage, (b) At controlled stage and (c) After 4 weeks of vitamin E supplementation in dosage of 400 mg daily. The parameters of control included fasting blood sugar < or = 140 mg%, post prandial < or = 200 mg and HbA1c < or = 7% (analysed by prepared kit). RESULTS: The significantly raised levels of MDA and decreased levels of reduced glutathione and vitamin E during uncontrolled stage of diabetes indicated free radical stress inducing lipid peroxidation. The significant fall of MDA and rise in reduced glutathione and vitamin E levels in blood after optimal control revealed its beneficial effect on oxidative stress. The levels were not normalised but still stayed higher than controls. After 4 weeks of vitamin E supplementation, further fall in MDA and rise in reduced glutathione suggested beneficial effect of vitamin E over and above the optimal control. Vitamin E estimation in blood at this stage did not constitute parameter of oxidative stress as it was provided from outside but was done to know the compliance of patients. Normalisation or near normalisation was not achieved with vitamin E therapy indicating persistence of oxidative stress. CONCLUSION: There was an evidence of oxidative stress in diabetes which decreased with optimal control and further declined after vitamin E supplementation indicating anti-oxidant effect of vitamin E alone. Normalisation of oxidative stress was not achieved. A further study is desired to study the effect of vitamin E for longer period at least 3-6 months before a definite conclusion is drawn.

Adult↗
PubMed1999

Subtypes of codeine cough syrup abusers.

This paper highlights the abuse potential of the codeine containing cough syrups, which may take two forms. One, experimental abuse in school or college students which later persists in a dependent pattern. Two, pre-existing opioid abusers, as a substitute which starts after the school or college years. The short term treatment outcome is better in the former group in that they are able to maintain abstinence for a relatively longer period.

Adolescent↗
PubMed1999

Immune responses to chloroquine--sensitive and resistant populations of Plasmodium berghei in mice.

In order to elucidate the role of the host as a factor in the spread of chloroquine resistance, a study of the host's immune responses in chloroquine resistant (cqr) and chloroquine sensitive (cqs) Plasmodial infections is essential. Course of the infection and the nature of immune responses in mice infected with chloroquine resistant (R) and chloroquine sensitive (S) strains of Plasmodium berghei were compared. Crude parasite antigen activated T cells from both the groups of mice (R and S) and the parasite specific antibodies were detected in the sera of both the groups. The differences in immune responses between the control (uninfected) and infected mice were found to be significant. However, humoral and in vitro cellular responses obtained with T cells from chloroquine resistant P. berghei primed mice was lower in comparison with the responses obtained with T cells from the sensitive infections. Our studies therefore suggest that immunosuppression to parasite antigen is seen in mice primed with chloroquine resistant P. berghei, which may play a role in the development of resistance.

Animals↗
PubMed1999

Inhibition of a protein tyrosine kinase activity in Plasmodium falciparum by chloroquine.

The aim of the present study was to establish the importance of phosphorylation events for parasite growth and maturation. Investigations into the cytosolic Plasmodium falciparum protein tyrosine kinase (PTK) activity revealed that there is a stage specific increase in the activity, in the order ring < trophozoite < schizont in both chloroquine sensitive (CQ-S) and chloroquine resistant (CQ-R) strains (p < 0.05). Our data also show that in vivo conversion of the schizont stage to ring stage via release of merozoites is associated with a decrease in PTK activity. Piceatannol, a specific inhibitor of PTK inhibited the activity in both the CQ-S and CQ-R strains of the parasites. The presence of low levels of chloroquine (CQ) inhibited the cytosolic PTK activity in a dose dependent manner (IC50 = 45 mumoles or 23 micrograms/ml) in CQ-S strains. The effect of varying concentration of CQ on the kinetics of peptide phosphorylation reveal that CQ was a competitive inhibitor of PTK with respect to peptide substrate and non-competitive with respect to ATP indicating that CQ inhibits PTK activity by binding with protein substrate binding site. These data thus suggests that maturation of malaria parasite may be due to this cellular PTK and its inhibition by CQ could provide a hypothesis to explain its antimalarial activity and efficacy.

Animals↗
PubMed1999

Uncommon mesiodens--a report of two cases.

Mesiodens is a supernumerary tooth with a cone shaped crown and a short root situated between the maxillary central incisors. Supernumerary teeth occur as isolated dental findings or as part of a syndrome. They are frequently discovered when a normal tooth is either delayed in its eruption or displaced often resulting in arch length inadequacy. An early diagnosis allows early intervention, more favourable prognosis and minimal complications. Presented here are two cases of unusual bilateral mesiodens.

Adolescent↗
PubMed1999

Connation of permanent incisors: a report of two cases.

Presented here are two uncommon cases of connation of permanent incisors. The term connation is being used in this paper instead of fusion, gemination etc., as it ideally describes the anomaly. Various treatment modalities have also been recommended for such cases.

Child↗
PubMed1998

Induction of heme oxygenase-1 during endotoxemia is downregulated by transforming growth factor-beta1.

Heme oxygenase (HO)-1 generates CO, a gas with vasodilatory properties, during heme metabolism. HO-1 is expressed highly in vascular tissue after endotoxin stimulation, and generation of CO through the HO-1 pathway contributes to the hemodynamic compromise of endotoxic shock. Shock related to endotoxemia is an immune-mediated process that involves the generation of proinflammatory cytokines such as interleukin (IL)-1beta. Because transforming growth factor (TGF)-beta1 is a modulator of immune-mediated inflammatory responses and it blocks the hypotension of endotoxic shock, we determined whether TGF-beta1 could be used to reduce expression of HO-1 in vascular tissue and smooth muscle cells. In a rat model of endotoxic shock, lipopolysaccharide-induced HO-1 mRNA and protein expression was reduced by TGF-beta1 in highly vascularized tissue, such as heart and lung, by Northern and Western analysis. Furthermore, TGF-beta1 downregulated HO-1 mRNA after its induction by IL-1beta in vascular smooth muscle cells in culture. TGF-beta1 also decreased HO-1 but not HO-2 protein expression in these cells. TGF-beta1 decreased HO enzyme activity induced in IL-1beta treated vascular smooth muscle cells to a level not different from that in vehicle-treated cells. These studies suggest that this downregulation of HO-1 mRNA and protein expression and decrease in IL-1beta-induced HO enzyme activity may contribute to the beneficial effect of TGF-beta1 on endotoxic shock.

Animals↗
PubMed1998

Stabilization of Aldehydes as Propylene Glycol Acetals.

Propylene glycol (PG) acetals (substituted 1,3-dioxalans) of a few representative aldehydes are prepared according to standardized methods in yields of 80-90%. A comparative study of the regeneration of citral from the corresponding dimethyl and PG acetals under mild acidic conditions showed that, although the former readily decomposed to an extent of 85%, the latter formed a near 1:1 equilibrium mixture with the generated aldehyde.

Journal Article↗
PubMed1998

Effect of angiotensin converting enzyme inhibitors on ischaemia-reperfusion-induced renal injury in rats.

The present study was designed to investigate the effect of captopril, a sulfhydryl (-SH) containing ACE inhibitor and lisinopril, a non-SH containing ACE inhibitor, on ischaemia-reperfusion-induced renal injury in rats and to study the involvement of the free radical scavenging property of captopril in its renoprotective effect. Bilateral renal artery occlusion was induced for 30 min followed by reperfusion for 24 h. Blood samples were taken from retro orbital sinus before surgery and at 24 h after reperfusion for blood urea and blood creatinine estimation. After completion of 24 h of renal reperfusion the carotid artery was cannulated and the mean arterial blood pressure (MABP) was recorded. The left kidney was used for histological examination. The right kidney was utilised for estimation of mitochondrial thiobarbituric acid reactive substances (TBARS). Renal ischaemia, followed by reperfusion, significantly increased blood urea nitrogen (BUN) and blood creatinine. However, creatinine clearance decreased markedly. Captopril administered before renal artery occlusion or immediately after reperfusion and lisinopril pre-treatment significantly attenuated the increase in BUN and blood creatinine. Creatinine clearance was markedly better in captopril-treated animals as compared to lisinopril-treated rats. Captopril significantly decreased the degree of tubular necrosis, haemorrhagic streaks and urinary casts. Lisinopril treatment decreased tubular necrosis and urinary casts but no marked effect on haemorrhagic streaks was noted. Administration of captopril before ischaemia or just after reperfusion significantly reduced the elevated concentration of mitochondrial TBARS but no such decrease was noted in lisinopril-treated rats. Based on these results it may be concluded that captopril and lisinopril markedly protected against ischaemia-reperfusion-induced renal injury and any additional renoprotective effect of captopril may be ascribed to its free radical scavenging properties.

Angiotensin-Converting Enzyme Inhibitors↗