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Biomedical subjects

J Moreno

Publications and source records attributed to J Moreno.

At least 235 records · Page 13Linked to original sources
PubMed1982

Effects of vitamin D3 on the uptake and release of calcium by isolated intestinal mitochondria.

Administration of vitamin D3 or 1,25 (OH)2D3 to rachitic chicks produces a decrease of 45Ca uptake by mitochondria from intestinal mucosa. This effect of vitamin D3 shows tissue specificity, since it was not observed in liver mitochondria from the same animals. The Km values were similar (about 10 microM) for intestinal mitochondria from rachitic and treated animals. The Ca2+ efflux in previously loaded mitochondria was not changed by treatment. The Ca content of recently isolated mitochondria was strikingly lower after vitamin D3 administration. It is concluded that vitamin D3 may participate in the mechanism which regulates the intramitochondrial Ca concentration.

Animals↗
PubMed1982

Effects of the fungicide tridemorph on mitosis in Allium cepa.

A mitodepressive effect of Tridemorph on the meristematic cells of Allium cepa has been observed. This effect increases with the concentration of the fungicide and the length of treatment, until complete inhibition of cell division occurs under certain conditions. Furthermore, this chemical has been revealed as a strong c-mitotic agent, although there are clear differences between its action and that of colchicine and other c-mitotic drugs. Other important features are the alterations observed in the development of the different mitotic phases depending on the dose employed. A high degree of chromosome contraction has been observed since the cells are in prophase until they reach telophase. Multipolar anaphases and micronuclei, and anomalous chromosome separation and anaphase emigration are other important modifications induced by the treatment on the development of mitosis.

Chromosomes↗
PubMed1981

Intestinal absorption-partition relationships: a tentative functional nonlinear model.

Models and equations designed to elucidate passive intestinal absorption mechanisms by analysis of the relationship between the absorption rate constant (ka) and either the partition coefficients (P) or a related partition constant for homologous series of substances, are reviewed. Classical nonlinear physical models, such as those which assume the existence of a nonstirred layer or equilibrium extraction, predict sigmoidal or hyperbolic relationships between ka and P, whereas other models, which regard the membrane as a heterogeneous multicompartment system, predict parabolic or bilinear relationships between log ka and log P. In the present paper, an alternative model is proposed, which incorporates the Wagner-Sedman equilibrium extraction model together with the existence of pores, which play a fundamental role for compounds below 250 in molecular weight. Several apparently contradictory absorption-partition literature data are shown to be highly consistent with the tentative model proposed.

Diffusion↗
PubMed1981

Lack of relationship between activity of intestinal alkaline phosphatase and calcium or phosphate absorption.

The effects of vitamin D3 and the aqueous extract of Solanum malacoxylon on intestinal alkaline phosphatase and tissue phosphate content were studied on rachitic chicks treated with large doses of ethane-1-hydroxy-1,1 diphosphonate (EHDP). The EHDP treatment blocks the increase of intestinal calcium or phosphate absorption induced by the vitamin D3, while it has no effects on the rise of intestinal alkaline phosphatase activity or the increment in tissue phosphate content. The lack of correlation between the increment of alkaline phosphatase and that of Ca or phosphate absorption in vitamin D3 plus EHDP treated chicks excludes a participation of the alkaline phosphatase in the mechanism of Ca or P intestinal absorption. The Ca or phosphorus absorption are elicited specifically by 1,25-(OH)2-D3, while alkaline phosphatase activity and phosphate tissue concentration respond to a broader spectrum of stimuli.

Alkaline Phosphatase↗
PubMed1981

[Ackerman's verrucous carcinoma on the lower lip].

A patient with Ackerman's verrucous carcinoma located on the transitional epithelium of the lower lip is described. No previous cases have been reported with this location. The clinical course was similar to verrucous carcinoma arising on other areas of skin or mucosae. Viral particles were not found on ultrastructural studies. The response to conservative surgical treatment was excellent.

Adult↗
PubMed1981

[Nail-patella syndrome].

Four familiar cases of the Nail-patella syndrome are reported in this article. All the patients displayed clinical and radiographic changes characteristic of this syndrome. All of them had elongated and sharp-pointed postero-inferior iliac prominences. This bony abnormality has not been previously described in this syndrome.

Adult↗
PubMed1980

Expression of lactate dehydrogenase isozyme X in haploid cells of pigeon testis.

Electrophoretic patterns of lactate dehydrogenase (EC 1.1.1.27) from adult testes show the existence of three different phenotypes for the isozyme X or C4 in populations of racing homer pigeons. These phenotypes are the expression of two different alleles at the Ldh c locus. Analysis of electrophoretic patterns of lactate dehydrogenase from lysates of mature spermatozoa isolated from pigeons heterozygous at the Ldh c locus indicates that the two different alleles are expressed in haploid cells. It is concluded that transcription of the gene coding for isozyme X must occur only in pre-meiotic cells.

Animals↗
PubMed1980

An experimental assessment of the Wagner-Sedman extraction theory for the intestinal absorption of antibacterial sulfonamides.

The chromatographic parameters in a reverse-phase partition system and the rat gut in situ absorption rate constants for 18 antibacterial sulfonamides are highly correlated values. The correlation is logarithmic-logistic in nature, being in accordance with the Wagner-Sedman extraction theory for a constant pH value. Parabolic correlations did not satisfactorily fit the experimental data. This behavior, not frequently reported in regard to the intestinal absorption of drugs, is discussed in connection with other apparently contradictory available data.

Animals↗
PubMed1979

Occlusion of the cerebral arteries in Recklinghausen's disease.

Two children, aged 18 months and 6 years, who had Recklinghausen's disease, had occlusion of cerebral arteries. One child had no motor deficit but the other had right hemiparesis and partial occlusion of the left posterior cerebral artery, a fact not found in the literature.

Arterial Occlusive Diseases↗
PubMed1979

Pancreatic encephalopathy.

A prospective study was conducted on 17 cases of acute pancreatitis; encephalopathy was discovered in six patients (35%). The following parameters were studied: the usual ones in pancreatitis conditions (amylasemia, lipasemia, amylasuria, ions, glucose, pO2, pCO2, pH, etc.), and electroencephalographic changes and determinations in CSF of cells, proteins, lipase, amylase, lipides and cholesterol. A direct relationship was found to exist between the pancreatic encephalopahy condition and an increase in CSF-lipase. The electroencephalographic changes were nonspecific. The encephalopathy did not affect the course of the pancreatitis condition, and showed no relationship to type of treatment involved. The severity of the pancreatitis was not related to the presence or absence of encephalopathy.

Acute Disease↗
PubMed1978

Branched-chain amino acid aminotransferase in mouse testicular tissue.

Branched-chain amino acid aminotransferase (L-leucine:2-oxoglutarate aminotransferase, EC 2.6.1.6) activity was determined in several tissues of the mouse. Testis homogenates presented a specific activity very close to that of heart extracts which were the most active. Enzyme activity was detectable in testes from 5-day-old mice and increased steadily during development to reach a maximum at the 20th day of life. The transaminase was present in the cytosol of testicular homogenates and also associated, probably in the matrix, with a special type of mitochondria present in spermatozoa and gametogenic cells. The enzyme from testis is active against the three branched-chain amino acids and catalyses the reaction in both directions. Highest activity and lowest Km were obtained with L-leucine. Activity with L-valine was the lowest. The enzyme from the mitochondrial fraction showed identical properties to that from the soluble phase. The possible participation of this aminotransferase in a shuttle system transferring reducing equivalents from cytoplasm to mitochondria is postulated.

Animals↗