Supratentorial to infratentorial and antigravity migration of intracranial bullet.
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Biomedical subjects
Publications and source records attributed to M Tiwari.
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Histopathological studies of the cutaneous tissues of Wistar rats exposed to UV B radiation (294 nm) for 20 days and rats exposed to UV B radiation for 20 days, followed by topical treatment with benzoyl peroxide, a tumor promoter (20 mg/animal/0.2 ml acetone) twice a week for 1 month, and kept under observation for 12 weeks, demonstrate the development of malignancy. Pretreatment of the animals with 1-oxo-5beta, 6beta-epoxy-witha-2-enolide (20 mg/kg bwt.), isolated from the roots of Withania somnifera, prior to exposing the animals to UV B radiation, prevents the incidence of skin carcinoma. The administration of 1-oxo-5beta, 6beta-epoxy-witha-2-enolide, to the animals after exposing them to UV B radiation/UV B radiation and benzoyl peroxide also prevents the occurrence of malignancy in the cutaneous tissue. Immunohistochemical staining of the cutaneous tissues of rats exposed to UV B radiation show the presence of p53 + foci (clusters of cells containing the mutated p53 protein), whereas an absence of p53 + foci is observed in animals pretreated with 1-oxo-5beta, 6beta-epoxy-witha-2-enolide. These results prove that 1-oxo-5beta, 6beta-epoxy-witha-2-enolide has the potential for acting as an effective agent to prevent the incidence of skin carcinoma induced by UV B radiation.
The heterogeneous nature of the mutations, the size, and the complexity of the factor VIII gene makes direct mutation analysis in hemophilia A families in India an option that is not very feasible and practical. Thus, carrier screening and prenatal diagnosis of hemophilia A often depends on haplotype analysis using restriction fragment length polymorphisms (RFLP) and short tandem repeat (STR) markers to track the defective factor VIII gene within a family. The main objective of this present study was to assess the utility of using polymerase chain reaction (PCR)-based five polymorphic markers: four intragenic Hind III, Bcl I, intron 13, and intron 22 STRs and one extragenic marker St14 in prenatal diagnosis. Forty-one chorionic villus samples (CVS) were studied from 41 families with a history of hemophilia A. PCR and RFLP were used for screening. Intron 22 STR showed the highest informativeness (60.9%), followed by Hind III (51.2%), Bcl I (46.3%), & intron 13 STR (51.2%); the extragenic marker St14 (VNTR) was informative in 46.3% of families. Linkage analysis, with the combined use of these five PCR-based polymorphic markers, gives good informativeness of 87.8% in the Indian population. Of the 41 CVS tested, 21 were found to be male fetuses and of these 13 were found likely to be affected with hemophilia A. Only in 12.2% of the families were none of the markers informative.
Thyroid hormone (TH) deficiency results in delayed proliferation and migration of cerebellar granule cells. Although extensive cell loss during the development of the cerebellum under hypothyroid conditions is known, its nature and its mechanism are poorly understood. Bcl-2 family gene expression is known to determine the fate of cells to undergo apoptosis. We evaluated the effect of hypothyroidism on Bcl-2 family gene expression in the developing rat cerebellum. Electrophoresis and Western blotting were used to analyze DNA fragmentation and expression of DNA fragmentation factor (DFF-45), Bcl-2, Bcl-xL and Bax genes respectively. In the hypothyroid condition, extensive DNA fragmentation and enhanced cleavage of DFF-45 were seen throughout development (postnatal day 0 to day 24) and adulthood whereas they were absent in the euthyroid state. The anti-apoptotic genes Bcl-2 and Bcl-xL were down-regulated and the pro-apoptotic gene Bax was expressed at higher levels compared with the euthyroid state. These results suggest that normal levels of TH prevent cerebellar apoptosis to a large extent, whereas hypothyroidism not only increases the extent but also the duration of apoptosis by down-regulating the anti-apoptotic genes and maintaining a high level of the pro-apoptotic gene Bax.
Essential structural and physicochemical requirements in terms of common biophoric sites (pharmacophore) and secondary sites for binding and interacting with AT1 and AT2 receptors have been identified using APEX-3-D expert system on 16 N2- aryl triazolinone biphenyl sulphonamides. Among several biophoric 3-D QSAR models two models (Nos. 1 and 2) having R2 > 0.7, chance <0.05 and match >0.5 and two models (Nos. 3 and 4) having R2 > 0.89, chance <0.03 and match >0.5 with three biophoric sites and two secondary sites (except model No. 4 with three secondary sites) describe the variation in AT1 and AT2 antagonistic activities, respectively.
In the current study we report the perturbation of key enzymes of the heme metabolic pathway, i.e. delta-amino levulinic acid synthase, heme oxygenase and biliverdin reductase, in vivo by administration of retinoic acid (RA) and retinoic acid in association with tin-metalloporphyrins, viz., tin-protoporphyrin (SnPP) and tin-mesoporphyrin (SnMP) in the liver, spleen, heart and lung of rats. RA at a dosing regimen of 50,000 I.U. stimulated splenic ALA-S activity, whereas co-administration of tin-metalloporphyrins with RA antagonised the RA mediated induction of ALA-S. In the other tissues viz., liver, heart and lung our results showed a diminution of ALA-S activity on RA administration, the level of repression was further attenuated when tin-metalloporphyrins were co-administered with RA. This marked suppression of ALA-S brought forth by concurrent administration of RA and tin-metalloporphyrins is suggestive of the beneficial effect of this formulation in acute attacks of porphyria, similar to heme. Furthermore, our results emphasize that the combined dosing of RA with tin-metalloporphyrins leads to a substantial decline in bilirubin levels due to a profound inhibition of HMOX in the probed tissues. The features of the combined action of RA and tin-metalloporphyrins in vivo lead to a substantial suppression of formation of the potentially toxic metabolite bilirubin, and the enhancement of disposal of the untransformed substrate (heme) of the enzyme that is inhibited. These results define some of the characteristics of a therapeutically useful formulation and represent a new therapeutic approach for the amelioration and management of hyperbilirubinemia.
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To compare the efficacy of a short course of ceftriaxone with a standard course of chloramphenicol for typhoid fever, a randomized trial was conducted in 46 patients (30 adults and 16 children) who were blood culture-positive for Salmonella typhi or S. paratyphi. Ceftriaxone was given intravenously once a day for three days to 15 adults at a dose of 2 g/day and to eight children at a dose of 50 mg/kg/day. Chloramphenicol was given orally four times a day to an equal number of patients at a dose of 60 mg/kg/day until defervescence, followed by 40 mg/kg/day for a total of 14 days. Clinical cure without complications or relapse occurred in 19 patients (83%) treated with ceftriaxone and in 20 patients (87%) treated with chloramphenicol (P > 0.05). Four patients with clinical failures in the ceftriaxone group included two with fever lasting six days or more, one with altered sensorium, and one with relapse; three patients treated with chloramphenicol developed leukopenia and thrombocytopenia and were switched to amoxicillin therapy. Bacteriologically, blood cultures of all 46 patients were sterile three days after the start of treatment, and remained so through day 15 of follow-up. These results extend previous observations on the efficacy of ceftriaxone in short courses for both adults and children with typhoid fever.
Ceftriaxone in short courses has emerged as an effective alternative to chloramphenicol for the treatment of typhoid fever. To study the pharmacokinetics of ceftriaxone in acute typhoid fever, 10 febrile Nepalese adolescents and young adults with blood culture-positive illness were treated with 3 g of ceftriaxone (intravenous infusion for 30 min) daily for 3 days. On the 1st and 3rd day of treatment, blood and urine samples were collected at defined intervals for measurements of drug concentrations. Kinetic parameters including concentrations at the end of infusion (Cmax) and 24 h after the end of infusion (Cmin), elimination half-life (t1/2), area under the plasma concentration-time curve (AUC), total plasma clearance, renal clearance, percentage excreted in urine, and volume of distribution were estimated. On day 1, mean values were as follows: Cmax, 291 micrograms/ml; Cmin, 21.7 micrograms/ml; plasma t1/2, 5.2 h; AUC, 1,428 micrograms.h/ml; total plasma clearance, 37 ml/min; renal clearance, 19 ml/min; percentage excreted in urine, 49.7%; and volume of distribution, 16.1 liters. Mean values on day 3 were not significantly different from those on day 1. Compared with published values for healthy volunteers who received the same dose, our mean t1/2s and AUCs were lower and our mean total plasma clearances, renal clearances, and volumes of distribution were higher. The good clinical responses of these patients to therapy and the adequate Cmins support the use of ceftriaxone once daily for the treatment of typhoid fever.
A rapid method for fixation and embedding of plant materials, especially pteridophytes, is suggested. Addition of tannic acid following osmication improved the visualization of membranes. Staining en bloc with uranyl acetate between osmication and tannic acid is suggested for tissues infected with fungi and bacteria.
To study mechanisms of antibiotic effects in typhoid fever, levels of interleukin-6 (IL-6), gamma interferon (IFN-gamma), and cytokine receptors (tumor necrosis factor receptor [TNF-R] p55 and TNF-R p75) were measured in the plasma of 29 adult Nepalese with culture-positive typhoid fever before therapy and on days 4 and 15 after start of therapy with either ceftriaxone at 2 g/day for 3 days or chloramphenicol at 50 mg/kg of body weight per day for 14 days. Bacteriologic cure was defined as blood cultures testing negative on days 4 and 15 after start of therapy; clinical cure was defined as symptomatic improvement within 5 days after start of therapy and absence of relapse. Clinical and bacteriologic cures occurred in 24 patients. There were two clinical failures, two patients who failed to complete therapy because of leukopenia, and one relapse. Mean levels before therapy were elevated compared with those in healthy controls (IL-6, 11.4 pg/ml; IFN-gamma, 1.3 ng/ml; TNF-R p55, 3.8 ng/ml; and TNF-R p75, 6.1 ng/ml) and fell progressively during and after therapy. For six patients (three in each treatment group) who showed prolonged fever (> 5 days) or relapse, mean levels of IL-6 and TNF-R p55 before therapy (29.5 pg/ml and 6.1 ng/ml, respectively) and on day 4 (17.7 pg/ml and 4.0 ng/ml) were significantly greater than corresponding means for 23 patients who showed early defervescence (on admission, 6.7 pg/ml and 3.3 ng/ml, and on day 4, 1.8 pg/ml and 2.7 ng/ml, P < .05). These results indicate that the concentrations of plasma cytokines and their receptors are elevated in typhoid fever and that these concentrations can be useful in predicting outcome.
Effects of localized low (2.5 Gy) and high (10 Gy) levels of gamma irradiation on the testis of albino rats were studied. A marked increase in the testicular total lipid, phospholipid and cholesterol content was observed at all post-treatment intervals except at 16 weeks where the contents decreased. A significant decrease in the activity of acid phosphatase/g of testis was seen at both the doses, the minimum value being at 4 weeks. The decrease in acid phosphatase activity is correlated with the state of germ cell population in seminiferous tubule which is found to be depleted at 4 week interval. The alkaline phosphatase activity/g testis however, showed a significant increase, the maximum being at 4 weeks post-treatment. Thereafter, the values of the enzyme activity showed a slight recovery at 16 weeks post-irradiation. ATPase activity increased initially followed by a significant decrease at all post-treatment intervals.
Sixty consecutive patients having multibacillary leprosy were examined for symptoms of nasal involvement and sinusitis. A complete ENT examination was carried out of all these patients and they were subjected to radiological examination of paranasal sinuses. Radiological abnormalities of maxillary antrum were found in 15 of 20 cases of lepromatous leprosy, 6 of 26 cases of borderline lepromatous and in 14 cases of mid-borderline leprosy. Localized or generalized mucosal thickening was the most common finding, followed by opacity of maxillary antrum. Radiological abnormalities were confirmed by antroscopy, which is the most appropriate technique for making an accurate diagnosis of maxillary antral diseases. Initially, antral involvement may begin with a localized area of mucol erythema, progressing to a typical granuloma formation and ulceration. The antero-inferior part of the antrum was found to be the most commonly affected region.