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Biomedical subjects

A Kalra

Publications and source records attributed to A Kalra.

At least 19 recordsLinked to original sources
PubMed1996

Transforming growth factor beta 1 improves wound healing and random flap survival in normal and irradiated rats.

OBJECTIVES: To evaluate the effect of chronic irradiation on wound healing and random flap survival (FV), and the effect of transforming growth factor beta 1 (TGF-beta 1) in this setting using an animal model. DESIGN: A randomized, controlled study with four groups of rats to study the effect of irradiation 4 months before surgical intervention. The effect of TGF-beta 1 on FV and wound healing also was evaluated in the irradiated and nonirradiated groups. SUBJECTS: Ninety-five rats were available for evaluation. Group 1 (n = 10) was the control; group 2 (n = 28) received TGF-beta 1; group 3 (n = 28) received radiation therapy; and group 4 (n = 29) received radiation therapy and TGF-beta 1. INTERVENTION: The irradiated groups received 15 Gy to their dorsal skin. Four months later all received McFarlane skin flaps. Groups 2 and 4 received topical TGF-beta 1, 4 micrograms, to the bed of the flap; groups 1 and 3 received saline. On postoperative day 7 all rats were evaluated for tensile strength and FV, and histologic staining with hematoxylin-eosin for collagen and TGF-beta 1 was done. The slides were evaluated in a "blinded" fashion. RESULTS: Irradiation decreased tensile strength and FV, but not to a notable degree. Transforming growth factor beta 1 improved tensile strength in the irradiated (P = .04, Student's t test) and nonirradiated groups (P = .05, Student's t test). Transforming growth factor beta 1 also improved FV in all groups, but significantly in the irradiation plus TGF-beta 1 group (P = .001, Student's t test). The TGF-beta 1 group had the most mature collagen present at the wound edge. No qualitative difference was seen in the immunohistochemical staining for the four groups. CONCLUSIONS: Transforming growth factor beta 1 improves wound healing and random FV in radiated and nonirradiated rat skin. Further study is needed to determine the radiation dose necessary to create an "impaired wound-healing model" in rats, and the optimum dose of TGF-beta 1 in this setting.

Administration, Topical↗
PubMed1993

Effect of nifedipine on oxidative damage of erythrocytes in Plasmodium berghei-infected mice.

It is known that the calcium channel blocker (CCB), nifedipine, can inhibit phagocyte oxidative burst in Plasmodium berghei-infected mice. The extent of immunopathological changes as seen by the course of infection and membrane lipid peroxidation in nifedipine-treated mice was examined in comparison with untreated mice at different parasite loads. The glutathione antioxidant system was also studied in these animals to assess its capacity to neutralize reactive oxygen species (ROS) in infected erythrocytes. The survival period of nifedipine-treated, infected mice decreased significantly. It was observed that the accumulation of reduced glutathione was greater and the decrease in glutathione peroxidase activity was less marked in drug-treated animals, suggesting better protection of the parasites against oxidative injury. The accumulation of the lipid peroxidation product, malonyldialdehyde was significantly lower in nifedipine-treated animals at all parasitemia levels studied, indicating decreased ROS generation and parasite damage. These observations reveal the shortcomings of using CCB to reverse the chloroquine resistance in malaria as this would minimize oxidative damage of parasitized red cells and phagocyte-mediated parasite killing.

Animals↗
PubMed1993

Effect of nifedipine on calcium status and chemiluminescence response of phagocytes during Plasmodium berghei infection in mice.

The macrophages and neutrophils from nifedipine-treated mice, both Plasmodium berghei-infected and uninfected, showed suppressed capacity to generate oxygen free radicals as compared with untreated controls. Nifedipine treatment did not affect resting state free calcium levels in these cells. But the rise in intracellular calcium levels of macrophages and neutrophils following P. berghei infection was significantly less (P < 0.05) in nifedipine-treated mice as compared with untreated groups at various parasitaemia levels. Probably this reflects a more potent effect of nifedipine on these cells in the depolarized state. Similarly, the rise in intracellular calcium levels of these cells following formyl-Met-Leu-Phe (fMLP) stimulation was also significantly less in nifedipine-treated groups than in untreated controls at different parasitaemia levels. A positive correlation between this fMLP-stimulated rise in calcium levels and the chemiluminescence response of macrophages and neutrophils was observed in nifedipine-treated and untreated groups at various parasitaemia levels. Thus the respiratory-burst responses of these cells during P. berghei infection depend on the calcium homeostasis in the cells. The disturbances of the calcium-regulating mechanisms by nifedipine treatment resulted in subnormal phagocytic cell responses which lead to more severe and rapidly fatal P. berghei infection in these animals.

Amino Acid Sequence↗
PubMed1993

Profile of accidents in children.

Out of 5031 children admitted to S.N. Hospital, Agra during one year, there were 716 cases (14.2%) of accidents. Most cases were in the age group of 4-9 years; boys were affected more commonly than girls. The maximum cases occurred due to fall (44.4%), followed by road traffic accidents (26.4%) and burns (11.5%). The consequences in terms of morbidity and mortality was also high. Kerosene oil ingestion was the most common encountered form of poisoning. Incriminating environmental factors could be identified in 51.8% cases and included poorly protected roofs (23.7%), poor state of roads (10.0%), defective vehicles (7.5%), and houses opening directly on the streets (7.3%). More than half of the accidents took place at home (58.7%), followed by those on streets (30.3%) or at farmhouses (57%). Injuries caused by sharp and blunt objects were more common in villages. Only 21.4% children had received first aid, often by the family, before reaching the hospital. The overall mortality rate was 53.1/1000, but in cases of burns the mortality was (146.3/1000). This study suggests that falls and traffic accidents have the highest incidence and mortality in childhood accidents and modification of the home environment can be an effective measure to prevent such incidents.

Accidents↗
PubMed1993

Altered course of Plasmodium berghei infection by nifedipine treatment.

The effect of nifedipine (a calcium channel blocker) on the course of P. berghei infection was examined. It was observed that mice receiving a daily dose of 0.015 mg/kg of nifedipine had significantly shorter prepatent, patent and survival periods as compared to untreated P. berghei-infected animals (p < 0.001). This shows that the calcium channel blockers, in addition to possessing the property of reversing drug resistance during combined therapy with chloroquine, may also alter the pathophysiology of malaria infection. The decreased resistance of the host to the invading parasite suggests that the effect of CCB on the host-parasite interaction in human malaria needs to be investigated further before CCB can be used in combination with chloroquine for the treatment of chloroquine-resistant malaria or for chemoprophylaxis.

Animals↗
PubMed1993

Prevalence of rheumatic heart disease in school children.

A total number of 8449 school children, in the 5-15 years old, group were examined clinically for evidence of valvular lesions and confirmed by roentgenographic electrocardiographic and echocardiographic findings. Twelve children (0.14%) were suffering from rheumatic heart disease (RHD). The disease was significantly more (p < 0.05) prevalent in the higher age group of 11-15 years as compared to younger children. Boys (0.18%) were affected more than girls (0.09%). The disease was more frequent among children belonging to economically backward group (0.34%) and those living in large families (0.28%). Children living in the slums had significantly (p < 0.05) higher prevalence (0.41%) than those residing in urban areas (0.06%). Only 3 out of 12 (25%) were previously diagnosed cases and remaining were diagnosed for the first time. Past history of rheumatic activity was seen in 41.67% cases. Mitral valve involvement was most frequent, being detected in 10 (83.33%) cases. Majority of cases (58.33%) had the development of symptomatic RHD within 2 years of having suffered from RF. Our study helped to detect the hitherto undiagnosed cases of RHD and showed that its prevalence was higher in older children and those from urban slums.

Adolescent↗
PubMed1992

Effect of nifedipine treatment on oxidative metabolism of peritoneal macrophages and neutrophils of Plasmodium berghei-infected mice.

The oxidative metabolism of peritoneal macrophages (PM) and neutrophils from nifedipine (calcium channel blocker)-treated, Plasmodium berghei (NK 65)-infected and normal infected Swiss Albino mice was studied. A significant fall in oxidative metabolism as evidenced by decreased chemiluminescence (CL) response (P less than 0.001) was recorded both in PM and neutrophils from nifedipine-treated mice compared to the control animals. When the oxidative metabolism of these phagocytes was studied after infection of the host, higher CL response was recorded from both PM and neutrophils isolated during the early course of infection (0-1 and 5-10% parasitaemia) when compared to uninfected mice (P less than 0.001). A similar pattern was observed in the case of nifedipine-treated and infected mice even though the CL response was much lower. The increasing parasite load not only resulted in subnormal CL response but also prolonged the time required for the phagocytes to exhibit peak oxidative activity both in normal infected and CCB-treated infected mice, but the time taken to show peak CL response was shortened following drug administration compared to controls. These observations revealed the profound in vivo effect of CCB on the functioning of phagocytic leucocytes and thereby questions the use of CCB in combination with chloroquine for reversal of drug resistance.

Animals↗
PubMed1992

Per rectal diazepam therapy in convulsive disorders.

One hundred and twenty children with persistent convulsions (lasting > or = 10 min) were treated with per rectal diazepam (dosage: 0.2 to 0.7 mg/kg/dose). Another group of 100 age matched children with convulsions, along with those who did not respond to rectal therapy were given intravenous diazepam in a dosage of 0.2 to 0.3 mg/kg/dose. Rectal treatment was effective in 80.83% cases while intravenous diazepam was effective in 90% cases which is statistically just significant (p < 0.05). No significant difference was observed in the efficacy of two routes of administration in controlling convulsions of different clinical types and various etiological groups (p < 0.05), except for primary generalized type where intravenous route was more effective than the rectal one (p < 0.05). No significant side-effect was observed with rectal therapy. Among the 23 (19.17%) children in whom rectal therapy failed, 12 (10%) responded to intravenous diazepam while the remaining 11 (9.17%) cases were resistant to both routes of administration.

Administration, Rectal↗
PubMed1991

Generation of reactive oxygen species by blood monocytes in human Plasmodium falciparum and P. vivax infections.

Generation of reactive oxygen radicals by peripheral blood monocytes was measured by luminol-dependent chemiluminescence in 23 P. vivax- and 7 P. falciparum-infected patients. The chemiluminescence index (CLI) was not found to be significantly higher in P. vivax-infected cases than in healthy controls. But in patients with P. falciparum infection, the CLI was significantly higher compared to controls as well as to P. vivax-infected patients. In two severe and complicated P. falciparum-infected cases, CLI was found to be higher than in mild cases. As immunosuppression is more marked in falciparum malaria than in vivax cases, the role of oxygen radical generation in immunopathology and causation of immunosuppression in falciparum malaria needs further investigation.

Animals↗
PubMed1990

Post-transfusion malaria in thalassaemia patients.

A total of 125 beta-thalassaemia patients receiving repeated blood transfusions were screened by Giemsa stain, Acridine-orange stain and antigen detection for evidence of malaria infection on each visit. A total of 8 (6.4%) of the patients developed post-transfusion malaria (PMT) as confirmed by tracing the infected blood donors. A high incidence of PTM in thalassaemia patients appears to be due to the use of fresh blood and the high frequency of blood transfusions required by these patients. Antigen detection using monoclonal antibody was found to be more sensitive for diagnosis of PTM and for screening suspected donors than the conventional blood smear examination methods and is therefore recommended for routine blood donor screening to rule out malaria infection.

Animals↗