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Biomedical subjects

L F Pallardo

Publications and source records attributed to L F Pallardo.

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

[Detection of gestational diabetes with the 50-gram glucose test: prevalence and relationship with to factors].

Prevalence of gestational diabetes was investigated in 222 pregnant women between the 24th and 28th weeks of gestation. A glucose screening test (GST) was performed with a 50 g glucose load, followed by a blood sample 1 hour later. Patients with glycemic levels greater than or equal to 140 mg/dl (7.8 mmol/l) 1 hour after the glucose administration were considered as having a positive GST and scheduled for a full oral glucose tolerance test (OGTT), which was interpreted according to O'Sullivan and Mahan criteria. Fifty-four patients had a positive GST, and 10 of them were diagnosed as having gestational diabetes mellitus. These figures indicate a gestational diabetes prevalence of 4.5% in general population and 18.5% in women selected by GST. The fetal weight index in patients with gestational diabetes was 1.13 +/- 0.10, whereas in normal women this index was significantly lower (p less than 0.01). Patients with positive GST and normal OGTT did not have an increased risk for fetal macrosomia. GST results were significantly higher in pregnant women with advanced age (greater than or equal to 35 years) and with late menarche (greater than or equal to 16 years), but did not vary according to maternal parity. Also, these results were significantly related with the number of risk factors for gestational diabetes encountered in a given patient, but not with any of them as examined alone, except for age. We conclude that GST performed in the 24th-28th weeks of gestation reveals 4.5% undetected gestational diabetes in our population. Certain maternal features (age, menarche, number of risk factors) influence on GST results.

Adult↗
PubMed1981

[Tubular function and renal acidifying in juvenile diabetes mellitus of short evolution].

The fractional excretion of uric acid, calcium, phosphorus, magnesium and other ions, and the urinary acidifying capacity were studied in then patients with juvenile diabetes of short evolution and in a control group matched for age, sex, and body surface. The diabetic patients showed a hyperexcretion of uric acid, sodium, potassium, chloride and ammonium which was unrelated to the increment of glomerular filtration rate or to glucosuria, and could not be ascribed to diet. The pathophysiologic interpretation of these findings is discussed, concluding that they might be the result of an increase in the filtered load and the behaviour of the tubules in front of the glomerular hyperfunction or metabolic disturbance inherent to the diabetic condition.

Adolescent↗
PubMed1981

Relation of kidney size to kidney function in early insulin-dependent diabetes.

Renal function and renal size have been studied in ten early insulin-dependent diabetic patients and in ten matched control subjects. Glomerular filtration rate, renal plasma flow and radiological kidney size were determined in each subject. Glomerular filtration rate and renal plasma flow were increased in diabetics (mean +/- SD: 169.6 +/- 16.1 and 690.1 +/- 52.6 ml/min/1.73 m2, respectively) compared with controls (120.6 +/- 9.7 and 605.9 +/- 67.2 ml/min/1.73 m2; p less than 0.001 and p less than 0.01). Calculated kidney weight corrected to 1.73 m2 of body surface area was elevated in diabetics (385.2 +/- 29.0 g) with respect to controls (277.5 +/- 17.5 g; p less than 0.001). No significant differences were found between diabetics and control subjects when glomerular filtration rate was expressed per gram calculated kidney weight, while renal plasma flow was significantly lower in diabetics than control subjects when so expressed (p less than 0.01). A positive correlation was found between glomerular filtration rate, renal plasma flow and kidney size in both controls and diabetics (p less than 0.01 in all cases). These findings support the conclusion that in the early state of diabetes glomerular hyperfunction is related to enlargement of the kidneys and augmented renal plasma flow.

Adolescent↗
PubMed1981

Renal tubular function and urinary acidification capacity in early juvenile diabetes.

Renal elimination of uric acid, calcium, phosphorus, sodium, potassium, chloride and magnesium and urinary acidification capacity were determined in ten insulin-dependent diabetics and in ten matched control subjects. The diabetics showed excessive excretion of uric acid, sodium, potassium, chloride and ammonia. Sodium, chloride and ammonia excretion fractions was also increased with respect to controls. The enhanced excretion of these substances in diabetics failed to relate to glomerular filtration rate, glycosuria or insulin requirements. These findings might be explained on the basis of glomerular filtration rate elevation, tubular response to this increment, and the underlying metabolic disturbances of diabetes.

Adolescent↗
PubMed1979

Diurnal variations of fecal and urinary iodine excretion in rats.

The present study was carried out to elucidate whether there are differences between the renal and fecal iodine patterns over 12-hour day and night intervals. Normal rats fed 125I-LID ad libitum and thyroidectomized animals maintained with 125I-labeled l-thyroxine showed diurnal changes in urinary and fecal iodine excretion, the highest values corresponding to the night period. The urinary volume and fecal weight were also increased during darkness hours. A positive correlation was found between the urinary loss of iodine and the quantitative iodine intake during any urine collection period. The changes of periodicity and timing of food intake alter the diurnal pattern of iodine metabolism. These observations suggest that the difference in food iodine intake between both periods constitutes the best explanation for the spontaneous cyclicity of urinary iodine excretion. However, as a significant difference in urinary iodine content exists between day and night periods in rats fed with the same amount of food within each period, and the morning corticosterone injection increases the renal loss of iodine in this period, it would indicate that other influences may be operative in regulating the diurnal variation of iodine excretion. In conclusion, the present results indicate that the high extrathyroidal metabolism of thyroid hormone and the high proportion of the hormone excreted into the feces during night hours may trigger off the TSH secretion in these situations, where an extrathyroidal pool of thyroid hormones were just adequate for normal peripheral requirements.

Adrenalectomy↗
PubMed1976

Thyroid iodine uptake, thyroid iodine secretion and plasma TSH levels in male rats during the day and night.

Experiments were performed to assess whether the diurnal changes in thyroid 131I metabolism are paralleled by variations in endogenous iodine. The uptake of iodide by the thyroid gland was determined by a double isotope technique. The T/S iodine ratio and the rate of 131I and 127I secretion from the thyroid gland were determined in rats fed LID during 20 days. The accumulation of iodine by the thyroid gland was prevented by CK1O4 and organic iodine formation was blocked by PTU. The absolute uptake of iodide by the thyroid gland was twice as high during the night than during the day. The thyroid/serum iodide ratios were highest during the night. The rate of release of 131I and 127I from the thyroid gland was augmented in the afternoon. The concentration of TSH in the plasma, measured by radioimmunoassay, was elevated in the afternoon as compared to other times during the day and night. The close association between the diurnal changes in thyroid iodine secretion and plasma TSH concentrations suggest that TSH may be responsible for the differences in iodine secretion observed during the day and night. On the other hand, the intake of iodine in the diet and the urinary clearance of iodine showed diurnal rhythms; the highest values occurred during the night. In addition, about twice as much iodine was available to the thyroid gland at night than during the day. These factors might also contribute to the diurnal variations observed in thyroid iodine metabolism.

Animals↗
PubMed1976

Diurnal variations of plasma and pituitary thyrotrophin in adult male and female rats.

Male and female rats fed a low iodine diet for 20 days were used to study the diurnal variations in resting levels of plasma and pituitary TSH concentration using a highly sensitive radioimmunoassay. Sex differences in the fluctuations in plasma TSH levels and in amount of TSH in the pituitary gland were observed. The daily fluctuations of plasma TSH were characterized by two peaks that occurred in males at 6 a.m. and at 3 p.m. while in females the peaks were delayed until 9 a.m. and 7:30 p.m. Moreover, in the females the morning and the afternoon peaks were of the same intensity while in the males the afternoon peak that occurred just before the onset of darkness was much greater than the morning peak. There was a fall in TSH content of the pituitary in the male rats at 6 a.m. and also in the afternoon just before the onset of darkness. Thus, the diurnal variations in the plasma and pituitary TSH levels were related in male rats. In the females, however, the pituitary TSH concentration did not reflect the changes observed in the plasma TSH levels. The level of plasma PBI did not appear to be responsible for the fluctuations in plasma TSH concentration. It is suggested that the main mechanism for the control of the circadian rhythm of TSH might be related to a high activity at night.

Animals↗