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Biomedical subjects

C Romero

Publications and source records attributed to C Romero.

At least 109 records · Page 6Linked to original sources
PubMed1986

Food glycaemic index or meal glycaemic response?

We have studied the glycaemic response to 50 g of carbohydrate (CHO) within a standard meal in order to ascertain the usefulness of the glycaemic index of food high in CHO for planning the diabetic diet. Carbohydrate was given in the form of three kinds of food: rice, potatoes and lentils, each having a different glycaemic index. Four types of standard meals were prepared with different energy distributions. A1,2,3: 60 per cent CHO, 10 per cent protein, 30 per cent fat and 1.35 MJ (322 kcal); A4,5,6: 60 per cent CHO, 30 per cent protein, 10 per cent fat and 1.37 MJ (327 kcal); B1,2,3: 40 per cent CHO, 20 per cent protein, 40; per cent fat and 2.08 MJ (498 kcal); B4,5,6: 40 per cent CHO, 40 per cent protein, 20 per cent fat and 2.08 MJ (499 kcal). The increase in postprandial blood glucose levels at 30 min was lower when lentils were given than with rice or potatoes in all four types of energy distribution used (P less than 0.01). No differences were found at the other times studied. The slope from time 0 to maximal increase of glycaemia was lower with lentils in meals B1,2,3 (P less than 0.006) and B4,5,6 (P less than 0.007) but not in A1,2,3 or A4,5,6. Areas under the curve of the glycaemic responses elicited by the foods studied were similar with all four types of energy distribution used. These similar glycaemic responses were unexpected since the three foods used have different glycaemic indices.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

A method for assaying the rhamnosidase activity of naringinase.

The use of the p-nitrophenyl-alpha-L-rhamnopyranoside for the specific measurement of the alpha-rhamnosidase activity of naringinase, by colorimetrically following the appearance of p-nitrophenolate anion, is proposed. Use of this synthetic substrate did not change the pH, temperature, or ionic strength optima of the enzyme. It did, however, result in (a) a decrease of the Michaelis constant of the enzyme, allowing the Vmax to be measured, this being impossible to accomplish with naringin, (b) an increase in the sensitivity of the assay to the presence of inhibitors in the reaction media, (c) an increase in the sensitivity which enabled measurement of low levels of naringinase due to the high absorptivity of p-nitrophenolate, and (d) a quick and cheap method of evaluating the alpha-rhamnosidase activity of naringinase.

Chromatography, High Pressure Liquid↗
PubMed1985

Homeorhesis during early lactation. Euthyroid sick-like syndrome in lactating cows.

Serum levels of thyroxine (T4), triiodothyronine (T3) and reverse T3 (rT3) were studied in dry, early (first trimester) and middle (second trimester) lactating purebred Holstein cows. The study encompassed three different seasons: autumn, winter and spring. Under comfortable weather conditions (temperature 22 degrees C; relative humidity, 40%) or moderately hot (28 degrees C; 60%), January and October, respectively, cows in early lactation exhibited significantly lower levels of T4 and T3, and higher values of rT3 than dry or middle lactating animals. In contrast, during May, when environmental temperature increased (34 degrees C; 40%), a clear-cut shift in T3/rT3 ratio occurred, and animals in early lactation exhibited the highest T3 and the lowest rT3 concentrations. These findings suggest that in dairy cattle, peripheral thyroid hormone metabolism plays a major role in regulating the homeorhetic responses involved in the maintenance of high priority functions.

Adaptation, Physiological↗
PubMed1985

Multicenter evaluation of assays for estradiol and progesterone in saliva.

Blood samples can be difficult to obtain in studies involving serial sampling, especially in developing countries where there may also be logistic, ethical, and cultural constraints that make frequent blood collection impractical. Assays for steroids in saliva may avoid some of these difficulties. A multicenter study involving laboratories in five countries was carried out to compare the results of assays for salivary estradiol and progesterone performed with centrally provided reagents and assay protocols. Concentrations of salivary steroid as obtained by all but one center were comparable with those reported in the literature. We conclude that assays of hormones in saliva are useful adjuncts to those performed on other body fluids.

Estradiol↗
PubMed1984

Auditory brainstem anomalies in albino cats: II. Neuronal atrophy in the superior olive.

In a previous paper (Brain Res., 260:1-9, 1983) we reported that albino cats show abnormal auditory brainstem evoked responses that appear to arise from structural defects in or near the superior olivary complex. In the present study, neuronal cross-sectional area in brainstem nuclei was compared in albino and normally pigmented adult cats. The albinos were true tyrosinase-negative (cc) and should not be confused with the deaf white cat (W); the albinos are not deaf. Neurons in the medial superior olivary nucleus (MSO) of albinos were, on average, 41% smaller than in pigmented animals; there was no overlap in the neuronal size distributions for the two groups of animals. Cell size in the lateral superior olive, medial nucleus of the trapezoid body, ventral nucleus of the lateral lemniscus, anteroventral cochlear nucleus, dorsal cochlear nucleus, and facial nucleus was also smaller (by 9-21%) in albinos than in pigmented animals but none of these differences was statistically reliable. In the abducens nucleus, neurons were 12% larger in albinos than in pigmented animals, demonstrating that neuronal size in the albinos is not uniformly smaller. Several lines of evidence suggest that the auditory system defects in albinos are related to abnormal pigmentation rather than to other gene effects. It is possible that a subtle pigment-related disruption of inner ear development in albinos results in a central cascade of atrophic changes along the auditory pathway.

Animals↗
PubMed1983

Spanish delta-beta-thalassemia: hematological studies and composition of the gamma-chains in ten homozygous patients.

We report the hematological studies and the composition of the gamma-chains of 10 homozygous delta beta(0)-thalassemia patients belonging to 6 families. These patients showed a mild to moderate chronic hemolytic anemia, morphological changes typical of thalassemia and 100% fetal hemoglobin in their peripheral blood. The homozygous studied synthesized A gamma- and G gamma-chains in approximately equal amounts, and the fetal hemoglobin with a threonyl residue at position 75 is present and accounts for all the A gamma production.

Adolescent↗
PubMed1979

Clinical value of carcinoembryonic antigen: diagnosis, prognosis, and follow-up of patients with cancer.

Plasma carcinoembryonic antigen (CEA) in nanograms per milliliter was assayed in 149 patients with benign and 567 patients with malignant disease. Elevated CEA level (greater than 5.0) was a good indicator of malignant disease but a poor screening test for cancer because of the high false-negative rate. Degree of elevation of plasma CEA level correlated with incidence of metastatic disease in patients with colorectal, gastric, and breast carcinomas, but no correlation was seen between CEA levels and status of lymph nodes in patients with localized disease. Patients with localized colorectal cancer, but elevated CEA levels before resection, had a 2.1-fold increase in the incidence of recurrence; however, this added to the prognostic value of Dukes' staging only when the CEA level remained elevated postoperatively. In 87% of patients with colorectal cancer, the CEA level was elevated at the time of recurrence, but a therapeutic value of reexploration for unexplained CEA level elevation was not confirmed.

Carcinoembryonic Antigen↗