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Biomedical subjects

A K Sharma

Publications and source records attributed to A K Sharma.

At least 217 records · Page 12Linked to original sources
PubMed1995

Topical timolol and lipid profile.

To evaluate the effects of topical timolol on lipid profile, blood samples from 25 patients (16 males and 9 females) were analysed before topical instillation of 0.5% timolol maleate and thereafter at one month and two months. After two months of therapy, the level of high density lipoprotein (HDL) decreased significantly (p < 0.02). The levels of low density lipoprotein (LDL), very low density lipoprotein (VLDL) and triglyceride increased but the changes were not statistically significant. Since low level of HDL is strongly associated with increased risk of myocardial infarction, our study cautions use of topical timolol in patients with low levels of HDL or with previous history of coronary heart disease.

Administration, Topical↗
PubMed1995

Intraoperative hypertension during thyroidectomy for Graves' disease.

Hyperthyroidism is well known to be associated with cardiovascular manifestations. The authors have noted that patients of well controlled Graves' Disease often pose problems due to intrapoperative cardiovascular instability. Retrospective analysis of 137 case records of patients with Graves' disease (n = 35), toxic nodular goitre (n = 42) and those with euthyroid benign goitre (n = 60) were studied. In Graves' disease cardiovascular instability was found in the form of hypertension (n = 9) associated with tachyarrhythmia (n = 8) and bradycardia (n = 3). The incidence of first 2 of the above mentioned 3 problems was significantly higher in Graves disease (n = 9/35 patients) in contrast to a comparable group of patients with toxic nodular in (3/42 patients; P value 0.05) and euthyroid goiter (2/60 patients; P value < 0.001). Certain parameters such as high T3, T4 at the time of presentation were associated with higher incidence of these complications, in spite of very well controlled thyrotoxicosis. Whether heightened receptor sensitivity to catecholamines and higher renin-angiotensin activation explain these findings in Graves' disease, remains to be ascertained.

Adult↗
PubMed1994

OEIS complex with craniofacial anomalies--defect of blastogenesis?

We report on a 31-week fetus with hydrocephalus, hypertelorism, microtia, short neck, vertebral and rib defects, scoliosis, omphalocele, exstrophy of bladder, absent external genitalia and pubic rami, imperforate anus, diaphragmatic hernia, defective lobulation of lungs, single kidney, bicornuate uterus, and flexion deformities of the limbs. Similar extensive anomalies in the rostral and caudal regions were described by Russell et al. [Pediatrics, 67:176-182, 1981] and Stewart et al. [Am J Med Genet, 45:426-429, 1993]. The patients described by them had a combination of the oculo-auriculo-vertebral sequence (OAV) and caudal deficiency sequence, whereas the patient reported here can best be described as a combination of OAV and OEIS (omphalocele, exstrophy of bladder, imperforate anus, spinal defects) complexes. The widespread malformations seen in our patient may be the result of an error during blastogenesis.

Abnormalities, Multiple↗
PubMed1994

GAPO syndrome in a child without dermal hyaline deposit.

A 5-year-old girl with GAPO syndrome from India lacked PAS-positive hyaline material in the skin biopsy from thigh and scalp. The role of this pathological change, earlier reported by Wajntal et al. [1990] in the pathogenesis of GAPO syndrome, needs to be reexamined.

Abnormalities, Multiple↗
PubMed1994

Biologically active recombinant human complement factor H: synthesis and secretion by the baculovirus system.

A complete cDNA clone (4.3 kb) encoding human complement factor H (hCFH; 155 kDa) has been cloned into the pVL1393 baculovirus expression vector and transfected into Spodoptera frugiperda Sf9 insect cells. A biologically active (92 +/- 15%) 140-kDa protein was secreted into the medium with a yield of more than 5 mg/liter. This is the first report of synthesis of biologically active recombinant hCFH in a heterologous system.

Animals↗
PubMed1994

Preaxial brachydactyly with abduction of thumbs and hallux varus: a distinct entity.

We describe a father and his daughter who had a unique pattern of preaxial brachydactyly, and unusual facial appearance. Both had short broad abducted thumbs and halluces. The second digits of both hands were also short and broad and those of feet were medially angulated. The radiographic findings were short first metacarpals and first metatarsals and hypoplastic phalanges of first two digits of hands and feet. A similar pattern of brachydactyly was described by Christian et al. [1972: Am J Hum Genet 24:694-701] and Mononen et al. [1992: Am J Med Genet 42: 706-713]. Our patients differ from those described by Christian et al. in that they did not have any mental retardation and from those of Mononen et al. by the absence of short stature and epiphyseal and metaphyseal changes. The heterogeneity of this new type of brachydactyly remains to be resolved.

Abnormalities, Multiple↗
PubMed1994

Transperineurial capillary abnormalities in the sural nerve of patients with diabetic neuropathy.

Morphometric techniques were employed to assess perineurial capillary abnormalities in the sural nerve of 20 diabetic patients with neuropathy and 10 normal control subjects. Structural abnormalities were related to quantitative neurophysiological and neuropathological measures of neuropathy. Perineurial capillary endothelial cell area (P < 0.001) and endothelial cell profile number (P < 0.01) were increased and luminal area (P < 0.001) was reduced in diabetic patients when compared with control subjects. A significant relationship was observed between endothelial cell hyperplasia and measures of neuropathic severity. These findings provide evidence for perineurial capillary luminal occlusion due primarily to both endothelial cell hypertrophy and hyperplasia. Such a reduction in luminal size is expected to reduce transperineurial and hence endoneurial blood flow, resulting in endoneurial hypoxia and hence human diabetic neuropathy.

Adult↗
PubMed1994

A dual immunocytochemical assay for oestrogen and epidermal growth factor receptors in tumour cell lines.

A new dual immunocytochemical assay for oestrogen receptor (ER) and epidermal growth factor receptor (EGFR) has been developed. It has been tested in a variety of conditions using cell culture lines and the results correlate well with those obtained from single immunocytochemical assays. MCF-7 and A431 cells and a mixture of the two types of cell were assessed immunocytochemically for ER and EGFR. ER showed immunopositivity of 30% in MCF-7 cells, 10% in the mixture and 0% in A431 cells. EGFR demonstrated immunopositivity of 0% in MCF-7 cells, 70% in the mixture and 100% in A431 cells. Dual immunocytochemical assays using anti-ER followed by anti-EGFR monoclonal antibodies on single histological sections showed similar reactivity to the single assays. Three staining patterns were seen in the mixture: ER+/EGFR- (MCF-7 cells), ER-/EGFR- (MCF-7 cells) and ER-/EGFR+ (A431 cells). ZR-75-1 and MDA-MB-231 cells and their retrovirally transfected counterparts ZR/HERc and MDA/HEGO cells were then analysed. The dual assay revealed the fourth phenotype (ER+/EGFR+) in 40% of ZR/HERc cells and in 10% of MDA/HEGO cells. This is the first description of a dual immunocytochemical assay system for ER and EGFR on single 5 microns frozen section samples. Studies are now underway assessing breast carcinoma sections which may allow investigation of the clonality of human breast cancer.

Breast Neoplasms↗
PubMed1994

Conformation of a T-cell stimulating peptide of interleukin-1 beta protein: circular dichroism studies.

A T-cell stimulating peptide Val-Gln-Gly-Glu-Glu-Ser-Asn-Asp-Lys-OH, the 163-171 fragment epitope of interleukin-1 beta (IL-1 beta), has been synthesized in solution phase and purified by reverse-phase high-performance liquid chromatography (RP-HPLC). The backbone conformation of the synthetic fragment, investigated in aqueous solution by circular dichroism (CD) spectroscopy, is qualitatively a mixture of beta-turns and random coil. Quantification of the CD spectra revealed the presence of a 9% beta-turn fraction in water at pH 7.0, suggesting the occurrence of the conformation for the epitope fragment in aqueous solution necessary for T-cell stimulation and antigenicity. Concomitant changes in CD spectra were observed with increases in the trifluoroethanol (TFE) concentration in water, and the beta-turn fraction in peptide increased to 28% at a concentration of 90% TFE. This helicogenic solvent, as well as other solvents such as methanol, acetonitrile and dioxane (all favouring an ordered structure in peptides), failed to induce any alpha-helical conformation in the IL-1 beta (163-171) fragment, and CD spectra were attributed to only beta-turn ordered structure. This beta-turn structure has also been found to be a theoretically preferred conformation using Chou-Fasman proclivity data and is in accordance with the presence of an all-beta-globular conformation for its parent molecule IL-1 beta. Thus, the beta-turn conformation is probably involved in retention of T-cell stimulation activity in this synthetic epitope.

Amino Acid Sequence↗
PubMed1994

Dosimetric accuracy of a dual photon energy linac at low monitor setting for various pulse repetition frequencies.

Accuracy of dose delivery at low monitor unit setting is studied for a dual photon energy linear accelerator. Dose delivered per MU is found to be constant for both the photon beams for MU settings above 30. For lower MUs there is definite deviation from the calibrated value and the error is found to be increasing as fewer MUs are set for dose delivery. This dose/MU ratio at low MU setting is found to be dose-rate dependent, showing an increasing trend with pulse repetition frequency (PRF). Also, the dosimetric ratio is observed to be mode dependent; its value for an 18 MV beam is almost double that observed in the case of a 6 MV beam at very low MU setting. The magnitude of this error should be determined for each energy so that appropriate corrections can be applied if very low MUs are to be used.

Particle Accelerators↗