Search PubMed⌕ Search

Biomedical subjects

M Castro

Publications and source records attributed to M Castro.

At least 253 records · Page 14Linked to original sources
PubMed1986

A comparative study of cefadroxil and co-trimoxazole in patients with lower respiratory tract infections.

The most common causative pathogens in lower respiratory disease are S. pneumoniae, H. influenzae and S. pyogenes. Cefadroxil and co-trimoxazole, both orally administered broad spectrum antibiotics, are effective against these organisms when given in a twice-daily regimen. In this open randomised study, 42 patients with lower respiratory tract infections received cefadroxil 1 g or co-trimoxazole 1 double-strength tablet every 12 hours for a mean duration of 11 and 13 days, respectively. Pathogens were isolated in the pre-treatment sputum of 51% of patients given cefadroxil and in 25% of those who received co-trimoxazole. Similar overall cure rates were observed after treatment with cefadroxil (67%) and co-trimoxazole (60%); sputum purulence was similarly diminished by both drugs (91% and 85%, respectively). Neither antibiotic caused serious side effects. Thus, in a convenient twice-daily regimen, cefadroxil and co-trimoxazole are comparably effective in treating lower respiratory tract infections.

Cefadroxil↗
PubMed1985

Deoxynucleotide sequence of an insect cDNA codes for an unreported member of the Chironomus thummi globin family.

Synthetic oligonucleotides served as probes to isolate insect globin clones from a Chironomus thummi cDNA bank. The cDNA insert of one clone (pC-S9) was completely sequenced by the dideoxy termination procedure. Beginning at the 5' end of the coding region, the 584 base pair sequence encodes most of an N-terminal hydrophobic signal sequence and the complete sequence for a mature secreted globin, and contains a polyadenylation recognition site 3' to an appropriate stop codon. The inferred amino acid sequence is that of an unreported variant of hemoglobin VIIB. Based on the number of differences between Hb VIIB chains, the pC-S9 gene has been evolutionarily independent longer than the other (two) members of the globin VIIB subfamily.

Amino Acid Sequence↗
PubMed1985

Serum concentration of 1,25-dihydroxyvitamin D in the human: diurnal variation.

The serum concentrations of many hormones exhibit regular circadian rhythms. To determine if the serum concentration of 1,25-dihydroxyvitamin D [1,25-(OH)2D], undergoes periodic changes during the day, we measured the serum concentration of 1,25-(OH)2D every 30 min for 28 h in five normal men. Serum concentrations and urinary excretion rates of calcium (Ca) and inorganic phosphate (Pi) also were measured. The results indicate that the serum concentration of 1,25-(OH)2D does not undergo any large fluctuations during the day, but, rather, is maintained within approximately 20% of its overall 24-h mean. In two of five men, part of the observed daily variation could be attributed to a low amplitude (less than or equal to 10%) circadian rhythm, with the mean acrophase occurring at 1645 h. The previously reported circadian rhythms in serum concentration and urinary excretion rates of Ca and Pi were confirmed. Although the rhythmic changes in serum 1,25-(OH)2D in two subjects were not correlated with the diurnal changes in the serum concentrations of Ca or Pi, a significant negative correlation (r = 0.61; P less than 0.001) was found between the circulating concentrations of Ca and Pi.

Adult↗
PubMed1983

Once daily administration of low-dose xipamide: a long-term study in mild to moderate hypertension.

The anti-hypertensive effects of xipamide in doses of 5-20 mg once daily were studied in a multicenter study. Three general practitioners recruited 74 patients with uncomplicated hypertension. After a run-in period, patients entered a dose-ranging study and were followed for an average period of 10.4 months. Supine and standing blood pressures were significantly decreased (22.2/14 and 21/14 mmHg) during xipamide therapy with average daily dose of 12.2 mg. Serum potassium values dropped from 4.43 +/- 0.06 to 3.96 +/- 0.5 mEq/l, and serum uric acid increased from 5.47 +/- 0.06 to 6.04 +/- 0.18 mg%. In a second part 47 patients entered a double-blind, crossover study of placebo. Their optimum xipamide doses confirmed that in the majority of patients with mild to moderate hypertension xipamide in doses lower than 20 mg is effective in lowering blood pressure. The study further confirmed that xipamide exerted its anti-hypertensive effects for at least 24 h.

Adult↗
PubMed1982

Methylmalonic acidaemia due to mutase apoenzyme defect: responsive to vitamin B12 in intact fibroblasts but not in vivo.

Congenital methylmalonic acidaemia (MMA-aemia) was diagnosed in an 8-month-old girl who presented with severe metabolic acidosis, hypoglycaemia and hyperglycinaemia. Vomiting, failure to thrive and apathy first appeared when breast feeding was replaced by a cows' milk formula at the age of 3 months. The patient, unresponsive to OH-Cbl therapy, was successfully treated with dietary protein restriction and with Shohl's solution. Aged 4 years 9 months, she is in good health. Studies in cultured fibroblasts revealed a defect of the MMA-CoA mutase apoenzyme. Mutase activity in cell extracts was barely detectable both with and without added coenzyme (Ado-Cbl). Addition of OH-Cbl to the culture medium improved overall propionate metabolism in intact fibroblasts but had no effect on mutase activity in cell extracts. These observations point to the presence of a very labile mutant enzyme, suggesting that the patient reported here may be suffering from yet another variant of MMA-aemia.

Amino Acid Metabolism, Inborn Errors↗
PubMed1982

Electrocardiographic changes after long-term treatment with sotalol in hypertensive patients.

The long-term electrocardiographic effects of sotalol, a beta blocker tha prolongs the cardiac repolarization time in animals, were investigated in ten hypertensive patients and compared to ten matched hypertensive patients treated with diuretics. An electrocardiogram was recorded before and during an exercise test on a bicycle. Heart rate was lower at rest and throughout exercise in the sotalol-treated patients. The PR and QT intervals of the ECG were significantly longer at rest and after exercise in the sotalol group, whereas QRS widths were similar in both groups. The QTC interval in the sotalol group was 0.41 +/- 0.02 s and 0.47 +/- 0.01 s, at rest and after exercise, respectively, which was not significantly different from 0.42 +/- 0.01 s and 0.43 +/- 0.02 s, respectively, in the diuretic group. These findings were discussed in relation to observations made with other beta blockers.

Adult↗
PubMed1980

Regulation of pancreatic and gallbladder function by absorption of intrajejunal phenylalanine in man.

The effects of varying loads of intraduodenal phenylalanine on pancreatic and gallbladder function were investigated in 32 healthy volunteers using a triple lumen perfusion system. L-phenylalanine absorption rates in the proximal jejunum were measured simultaneously. Intraduodenal L-phenylalanine produced a dose related increase in pancreatic secretion reaching the maximum at the concentration of 100 mM. Bilirubin outputs too increased significantly but did not parallel enzyme secretion. In contrast to the effect of L-phenylalanine, D-phenylalanine 50 mM did not stimulate pancreatic enzyme secretion and gallbladder emptying. The absorption rates of L-phenylalanine increased with rising luminal concentrations. There was a significant correlation between pancreatic secretion and L-phenylalanine absorption rates. This relationship suggests that the release of cholecystokinin, a hormone stimulating pancreatic and biliary function is dependant of the absorption of nutrients like amino acids.

Adult↗