Search PubMed⌕ Search

Biomedical subjects

C Valverde

Publications and source records attributed to C Valverde.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Demographic trends: birth spacing].

Two studies to measure children spacing in western metropolitan Santiago are compared. The first (1984-85) surveyed a sample of 687 mothers and the second 1,000. Deliveries took place at San Juan de Dios and Félix Bulnes hospitals (both state-finance) which provide medical care for medium and low income groups. Long spacing (5 years or more) accounted for the highest proportion of non-first born children (33.8% in 1984-85 with a significant increase to 40.1% in 1988) while short spacing (under 2 years) accounted for 19.2% in 1984-85 and 21.8% in 1988 (not significant). Mean birth weights were over 3,200 g in every spacing group. Despite the low illiteracy rate, predominant urban origin and having at least one child born before, high proportions of children were conceived despite the use of contraceptive measures (19.7% in 1984-85 and 22.5% in 1988). This contraceptive failure was less frequent among children born after longer spacings.

Birth Intervals↗
PubMed1987

Thyroid hormone profile in dairy cattle acclimated to cold or hot environmental temperatures.

Milk yields and the circulating profile of T4, T3 and rT3 were assessed during three different seasons of the year, in first trimester lactating (L) and in dry (D) multiparous holstein cows acclimated to distinct weather conditions. Within the thermoneutral zone (18-28 degrees C; 40-60% RH) and regardless of their geographical location, the thyroid hormone profile in all L-cows (n = 50) resembled the so-called euthyroid sick syndrome (T4, 43.7 +/- 7.7 nmol/l; T3, 1.31 +/- 0.10 nmol/l and rT3, 0.52 +/- 0.08 nmol/l). In both groups of animals the T3/T4 molar ratio was similar within the entire range of climates encompassed in the study. However, both groups exhibited a significant shift in the T3/rT3 molar ratio during cold (10 degrees C; 50%) or hot-dry (34 degrees C; 40%) weather conditions. This shift reaches maximum values (L, 6.5 +/- 1.2; D, 7.9 +/- 1.0 nmoles/l) under hot-humid conditions (28-42 degrees C; 60-90%). The relative increase of T3 levels from comfortable to cold or hot environmental temperatures, was significantly higher in L and D animals (30 vs 12%, respectively). Furthermore, only L-cows exhibited a significant decrease in the rT3/T4 molar ratio during either type of thermoregulatory demands, as well as a significant increase of T4 values under heat-acclimation. These results suggest that heat-acclimation in dairy cattle does not depress thyroid gland activity, and lend further support to the notion that adaptive thermoregulatory mechanisms in homeothermic vertebrates, involve adjustments in the peripheral monodeiodinative pathways of thyroid hormones.

Acclimatization↗
PubMed1987

[The enthesopathic shoulder].

61 shoulders of rheumatoid diseases, 23 of ankylosing spondylo-arthritis, 22 of psoriatic rheumatism and 30 of hyperostoses (Forestier's disease) were analysed and compared. There is a very significant difference between rheumatoid disease, on the one hand, and the other diseases, on the other hand. In ankylosing spondylo-arthritis, psoriatic rheumatism and hyperostosis, enthesophytes are observed; it is not the case in rheumatoid disease (unless associated with hyperostosis). The most frequent entesophyte is the one at the acromial insertion of the acromio-coracoid ligament ("bearded acromion"). It is also the easiest to visualise on an AP X-Ray of the shoulders. The association of a bearded acromion and an ulceration of the supero-lateral area of the humeral head (sulcus) is characteristic of spondylo-arthropathies (ankylosing spondylo-arthritis, psoriatic rheumatism) and is not found in hyperostosis. The ulceration of the sulcus is, on the contrary, common to spondylo-arthropathies and rheumatoid disease. This ulceration does not seem to be the sign of an inflammatory enthesopathy but rather a synovitis.

Aged↗
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↗
PubMed1983

Standard and higher doses of bromocriptine for severe chronic portal-systemic encephalopathy.

In a single-blind, cross-over fashion we assessed the therapeutic value of the dopamine agonist bromocriptine at doses of 15 and 20 mg/day plus cleansing enemas, versus the vigorous standard treatment of neomycin 6 g/day plus cleansing enemas. We studied four patients with severe chronic portal systemic encephalopathy. All the patients presented elevated prolactin levels. During the study the following parameters were assessed: mental state, number connection test times, frequency of asterixis, EEG, blood ammonia, and serum prolactin levels. In all but one patient, portal systemic encephalopathy parameters improved during the standard therapy, as opposed to both bromocriptine periods. During the period with 30 mg/day of bromocriptine all four patients developed precoma, although later one patient improved. Serum prolactin levels were rapidly suppressed during both bromocriptine periods. Prolactin levels did not correlate with changes in mental state. In patients with severe portal systemic encephalopathy, treatments with 15 and 30 mg of bromocriptine plus cleansing enemas were no better than the standard therapy.

Bromocriptine↗
PubMed1982

Polysomnographic effects of thyroid hormones primary myxedema.

Nine primary myxedematous patients were subjected to all-night polysomnographic recordings under the following conditions: (1) basal or myxedematous state; (2) acute replacement therapy (treatment with thyroid hormones at doses that increased weekly to the maximal replacement dose, Mrd); and (3) chronic replacement therapy (maintenance on the Mrd; euthyroid state). The most striking abnormality found in the sleep pattern during the myxedematous state was observed in both young adult (greater than 20 years old) and adult (greater than 50 years old) patients, consisting of either a complete absence or very low levels of slow wave sleep (SWS). Replacement therapy was accompanied by a restoration of the normal sleep pattern in 3 of the 4 patients that were followed. In contrast, younger patients (14-18 years old with a bone age of less than or equal to 10 years) had normal levels of SWS, with the exception of an adolescent with a bone age of less than 3 years. The latency for rapid eye movement (REM) sleep tended to increase during acute replacement therapy and became normal when euthyroidism was reached. These results lend support to the proposal that thyroid hormones exert central effects on the adult CNS.

Adolescent↗
PubMed1977

[A test for acute hypocalcemia using swine and salmon calcitonin].

The production of acute hypocalcemia was investigated using either 80 U. MRC of salmon calcitonin or 160 1. mrc of pork calcitonin in 117 subjects (58 patients with Paget's disease, 22 with osteoporosis, 22 with Sudeck-Leriche algodystrophy and 15 control subjects). The results obtained with the two types of calcitonin did not differ. Induced acute hypocalcemia was more pronounced in patients with Paget's disease than in the other subjects studied. In patients with Paget's disease there were statistically significant correlations between the hypocalcemia produced and the initial levels of alkaline phosphatase and total 24 hours urinary hydroxyproline.

Acute Disease↗