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Biomedical subjects

M Alvarez

Publications and source records attributed to M Alvarez.

At least 361 records · Page 20Linked to original sources
PubMed1986

In vitro activity of BRL 36650, a new semisynthetic penicillin.

BRL 36650 [sodium 6 beta-(D-2-[(4-ethyl-2, 3-dioxopiperazin-1-yl)carbonylamino]-2-(3,4-dihydroxyphenyl) acetamido)-6 alpha-formamido-penicillinate] is a new semisynthetic penicillin. It was tested in vitro for activity against 884 organisms cultured from blood specimens of cancer patients. BRL 36650 had broad-spectrum activity against the gram-negative bacilli tested but had no gram-positive activity. The MIC against 90% of the Pseudomonas aeruginosa isolates was 3.12 micrograms/ml. The activity of BRL 36650 was superior to that of piperacillin, comparable or slightly inferior to that of aztreonam and ceftazidime, and lower than that of imipenem and amifloxacin. BRL 36650 should prove useful for the management of gram-negative bacillary infections, including those caused by P. aeruginosa.

Bacteria↗
PubMed1986

[Aphthous ulcers and their syndromes].

With the object to clarify the different aphthous syndromes, their clinical manifestations, histopathological and radiological patterns and their evolution, the authors report three patients (26 year old woman with a bipolar aphthosis, Neumann type; 47 year old man with a Behcet's syndrome, and a 53 year old woman with a recurrent necrotic mucous periadenitis), pointing out that these entities are as important for dermatologists as for the other specialists.

Adult↗
PubMed1986

Effect of Stevia rebaudiana on glucose tolerance in normal adult humans.

The effect of aqueous extracts of Stevia rebaudiana leaves on a glucose tolerance test was investigated in 16 normal volunteers. Aqueous extracts of 5 grams of leaves were administered to volunteers at regular 6-h intervals for 3 days. Glucose tolerance tests were performed before and after extract administration. A second group of 6 normal volunteers who ingested an aqueous arabinose solution was also studied to eliminate possible stress effects. The extract of Stevia rebaudiana increased glucose tolerance. The extract significantly decreased plasma glucose levels during the test and after overnight fasting in all volunteers.

Adult↗
PubMed1986

Ovarian cavernous hemangioma.

Vascular tumors of the female genital tract are rare, especially those of the ovary. Most cases are small lesions that are discovered incidentally. We describe a 68-year-old woman with a benign hemangioma that presented clinically as a very large ovarian mass.

Aged↗
PubMed1985

Effects of Stevia rebaudiana natural products on rat liver mitochondria.

The effects of several natural products extracted from the leaves of Stevia rebaudiana on rat liver mitochondria were investigated. The compounds used were stevioside (a non-caloric sweetener), steviolbioside, isosteviol and steviol. Total aqueous extracts of the leaves were also investigated. S. rebaudiana natural products inhibited oxidative phosphorylation, ATPase activity NADH-oxidase activity, succinate-oxidase activity, succinate dehydrogenase, and L-glutamate dehydrogenase. The ADP/O ratio was decreased. Substrate respiration (state II respiration) was increased at low concentrations (up to 0.5 mM) and inhibited at higher concentrations (1 mM or more). In uncoupled mitochondria, inhibition of substrate respiration was the only effect observed. Net proton ejection induced by succinate and swelling induced by several substrates were inhibited. Of the compounds investigated, the sweet principle stevioside was less active. It was concluded that, in addition to the inhibitory effects, S. rebaudiana natural products may also act as uncouplers of oxidative phosphorylation. The possible physiologic consequences of the ingestion of stevioside and S. rebaudiana aqueous extracts are discussed.

Adenosine Diphosphate↗
PubMed1985

Adenosquamous carcinoma of the colon.

Two cases of primary adenosquamous carcinomas of the sigmoid colon and rectum are presented. Clinical features and pathologic findings of both primary and metastatic lesions are reported (including immunohistochemistry and electron microscopy). We emphasize that the presence of a metastatic squamous tumor in a patient with an unknown primary does not exclude the possibility of colonic carcinoma. Comparison with other reports in the American medical literature indicates that these are very aggressive tumors that may have a worse prognosis than the more common form of colonic adenocarcinoma. Furthermore, the squamous component, in particular, may have a greater potential for metastasizing and can do so as an undifferentiated-appearing carcinoma. In view of this, the authors suggest that very poorly differentiated areas within colonic adenocarcinomas should be very carefully evaluated by means of immunoperoxidase stains and/or electron microscopy in an attempt to identify squamous features.

Adenocarcinoma↗
PubMed1985

Electron microscopic diagnosis of cerebral toxoplasmosis. Case report.

Rapid and specific diagnosis of infections involving patients with acquired immunodeficiency syndrome (AIDS) is imperative. Toxoplasmosis is one of the most frequent causes of central nervous system disease in these patients. The authors present a case of cerebral toxoplasmosis in an AIDS patient, diagnosed by electron microscopy of brain biopsy tissue using rapid techniques.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Kinetics and mechanism of enzymatic hydrolysis of pivampicillin monolayers.

A study of the enzymatic hydrolysis of pivampicillin (an insoluble penicillin) extended as a monolayer on the aqueous interface at a constant surface pressure has been performed. Penicillinase promotes intensive hydrolysis of the pivampicillin monolayers, inducing their solubility. However, no action was observed with dog liver esterase. The hydrolytic process, which was dependent on the film surface pressure and on the quantity of the injected enzyme, is of the Michaelis-Menten type in two dimensions.

Ampicillin↗
PubMed1984

[Seasonal dynamics in the development of Boophilus microplus and Amblyomma cajennense in Camagüey, Cuba].

Studies were carried out on the occurrence of the Ixodic ticks in farm animals in the province of Camagüey, Cuba. Most spread proved to be the Boophilus microplus and Amblyomma cajennense species. As many as three waves of parasitic activity were seen with B. microplus: at the end of the winter season, in the months of May and June, and in the autumn (October and November). Only one wave was there with the activity of A. cajennense, covering the period of March-September.

Animals↗
PubMed1983

[Alcoholic hepatitis in an internal medicine service].

Twenty patients with alcoholic hepatitis are studied. It is remarked the low frequency of this disease in patients admitted to the Internal Medicine Ward. Jaundice forms were the most frequent. Clinical, humoral and histological characteristics are analyzed. World literature is reviewed bringing up-to- date this research.

Adult↗