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S Sharma

Publications and source records attributed to S Sharma.

At least 1,315 records · Page 73Linked to original sources
PubMed1984

Distal regulatory functions for the uvrC gene of E. coli.

We find that the uvrC gene is preceded by three promoters (P1, P2 and P3), identified by heparin-resistant RNA polymerase-DNA complex formation, P2 and P3 promoters are located proximal to the 5' end of the uvrC gene, while the P1 promoter is separated from the uvrC structural gene by an interposed DNA region of more than 1 kb. We have reported that P2 and P3 are not sufficient to promote uvrC complementation. However, plasmids containing the direct fusion of the P1 promoter to the uvrC gene complements the uvrC defect. Insertion of IS1 downstream from the P1 promoter leads to efficient synthesis of the uvrC protein as measured in maxicells. Fusion of the lac promoter to the uvrC structural gene can substitute for in vivo regulatory functions. We conclude that uvrC protein synthesis is controlled in a complex manner and that a distal promoter, P1, is required.

Bacterial Proteins↗
PubMed1984

Dysgerminoma of the ovary.

Dysgerminomas of the ovary are rare germ cell tumors. They are more common at puberty. Surgery followed by irradiation has resulted in excellent cure rates in early stages of this disease. This paper is a review of six patients with a diagnosis of dysgerminoma who were treated at the Department of Radiation Oncology, University of Louisville. The controversy on the use of irradiation in Stage Ia tumor is discussed in detail. A review of the literature is also done in this paper.

Adolescent↗
PubMed1984

Alpha 2-adrenoceptor antagonism and other pharmacological antagonist properties of some substituted benzoquinolizines and yohimbine in vitro.

Comparison of pA2 values for antagonism of clonidine induced inhibition of the electrically evoked contraction of the rat isolated vas deferens (alpha 2-adrenoceptor) and antagonism of contractions to methoxamine on the rat isolated anococcygeus (alpha 1-adrenoceptor) showed a group of substituted benzoquinolizines (Wy 25309, 26392 and 26703) to be more potent and more selective alpha 2-adrenoceptor antagonists than yohimbine. The benzoquinolizines and yohimbine enhanced stimulation-evoked overflow of tritium from rabbit isolated pulmonary arteries preloaded with [3H]-noradrenaline, as expected for alpha 2-adrenoceptor antagonists. In contrast to the results on the rat vas deferens, yohimbine was more potent than the benzoquinolizines. At higher concentrations all the alpha-adrenoceptor antagonists reduced the stimulation-evoked contraction of the pulmonary artery. The benzoquinolizines were competitive antagonists of 5-hydroxytryptamine on the rat isolated ileum. Wy 25309 showed only weak activity (pA2 = 5.21) whereas Wy 26703 was more potent (pA2 = 7.25). Yohimbine was a potent antagonist of 5-hydroxytryptamine. Wy 26703 was the only compound to have histamine antagonist effects in the guinea pig isolated ileum and to antagonise the chronotropic effect of isoprenaline on the isolated atria of the guinea pig and in both instances activity was weak (pA2 values 5.3 and 5.5 respectively). Yohimbine reduced the spontaneous beating of the atria at 3 X 10(-6) M. No compound at 10(-5) M antagonised acetylcholine on the guinea pig ileum. These novel substituted benzoquinolizines should be useful experimental compounds for the study of alpha 2-adrenoceptor mediated responses.

2H-Benzo(a)quinolizin-2-ol, 2-Ethyl-1,3,4,6,7,11b-↗
PubMed1984

Vulnerability to ventricular fibrillation in patients with clinically manifest ventricular tachycardia.

Ventricular vulnerability may be assessed by measuring the threshold current for the induction of ventricular fibrillation (VF). This technique has been widely utilized in animal experimentation and has been safely applied in a small number of clinical studies. We measured the VF threshold (VFT), using the single stimulus technique in 10 patients with coronary artery disease just prior to the institution of cardiopulmonary bypass. There were no adverse effects of VFT measurement. Three patients had nonsustained ventricular tachycardia (VT) on 24-hour ambulatory monitoring and had VFTs of 10, 14, and 16 mA. In this group VF was induced without any preceding repetitive ventricular responses. Seven patients had no repetitive forms on ambulatory monitoring. Their VFTs ranged from 30 to greater than 40 mA (mean greater than 37). Repetitive extrasystoles were regularly observed in this group at current intensities which ranged from 53% to 80% of the VFT. Thus patients with manifest VT appear to have an enhanced vulnerability to VF. Single or multiple responses were not observed in these patients but appeared to be present in patients with coronary disease and no demonstrable rhythm disorder.

Aged↗
PubMed1984

Studies of potential filaricides: Part 14--Activity of 1-iso-butoxycarbonyl-4-methylpiperazine against experimental filariasis.

The synthesis and filaricidal activity of 1-iso-butoxycarbonyl-4-methylpiperazine against Litomosoides carinii in Sigmodon hispidus and Dipetalonema viteae in Mastomys natalensis is reported. At an intraperitoneal or oral dose of 3 mg/kg given for 6 days, the compound removed 91% of the circulating microfilariae but had no effect on adult L. carinii. However, it killed all microfilariae and adults of D. viteae at a subcutaneous dose of 50 mg/kg given for 6 days. The compound also possessed chemoprophylactic activity against the larvae of L. carinii and D. viteae at a dose of 30 and 50 mg/kg respectively.

Animals↗
PubMed1984

3,5-dibromo-2'-chloro-4'-isothiocyanato salicylanilide in the control of Hymenolepis nana in rats--a pilot study.

The efficiency of a new anticestode compound, 3,5-dibromo-2'-chloro-4'-isothiocyanato salicylanilide (GUPTA et al. 1980) for mass eradication of hymenolepiasis from rat colonies was assessed in a pilot study. The drug was administered with milk or food. For effective eradication, depending on the size of animals, single or multiple doses of 100 to 500 mg of the drug/kg body-weight, mixed in milk, or 50 mg/kg in feed were necessary. Better results were obtained when the compound was given in feed as it ensured effective consumption irrespective of the seasonal variations. The efficacy of the compound was also assessed on cysticercoids in intermediate hosts (Tribolium confusum) by feeding them on flour medicated at 5%, 1% and 0.1% levels. None of the concentrations killed the larvae or arrested their development.

Animals↗
PubMed1984

Evidence for an intracellular precursor for human B-cell growth factor.

Human B-cell growth factor has been described as a trypsin-sensitive protein of Mr 12,000-14,000. Evidence is provided herein that this relatively low molecular weight product may be released from a larger precursor molecule of Mr 60,000-80,000. The precursor protein is confined to the cytosol of freshly isolated T lymphocytes, and only the Mr 12,000-14,000 moiety is released upon lectin stimulation. The precursor protein was subjected to limited tryptic digestion, which demonstrated that the biologically active fraction of the moiety resided in a relatively low molecular weight fragment. The T lymphocyte routinely possessed an intracytoplasmic pool of the precursor protein, the amount of which cyclically varied depending upon its depletion by the secretion process of a lower molecular weight product. Analysis of the mRNA size coding for the majority of B-cell growth factor activity, determined by translation in Xenopus laevis oocytes, suggested that the B-cell growth factor-specific mRNA resided in the greater than or equal to 15S range. This value is consistent with the size of the larger precursor. Therefore, it is proposed that a precursor-product relationship exists for the processing of human B-cell growth factor, analogous to that which has been described for several other cytokines.

Animals↗
PubMed1984

Clinical and hemodynamic correlates in pulmonary embolism.

The clinical presentation of pulmonary embolism may be dominated by manifestations of pulmonary infarction or by the signs and symptoms of an acute hemodynamic disturbance. Most often, some manifestation is present along with hemodynamic abnormalities, which may range from shock or cardiac arrest to tachycardia.

Blood Pressure↗