PubMed Health⌕ Search

Biomedical subjects

C Fardella

Publications and source records attributed to C Fardella.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Nifedipine reduces the increase of free intracellular calcium in primary hyperparathyroidism: role of calcium channels and PTH].

Free intracellular calcium is increased in primary hyperparathyroidism (HPT) and may be related to the higher incidence of hypertension in this disease. This elevation returns to normal when primary HPT is corrected. In essential hypertension, an alteration in calcium channels allows a intracellular accumulation of calcium. Aiming to asses if a similar mechanism operates in primary HPT, we measured intracellular calcium concentrations using QUIN-2-AM, before and after a 10 mg sublingual dose of nifedipine, in 9 subjects with primary HPT, 12 subjects with essential hypertension and 17 normal controls. Intracellular calcium was higher in subjects with primary HPT and with essential hypertension than in normal controls (276 +/- 56, 343 +/- 50 and 113 +/- 12 nM respectively). Among patient with primary HPT, intracellular calcium correlated with plasma PTH (r = 0.82). Nifedipine reduced intracellular calcium to 173 +/- 36 nM in subjects with primary HPT and to 188 +/- 35 nM in those with essential hypertension. In the latter, the decreased in intracellular calcium and blood pressure correlated significantly (r = 0.65 p < 0.03). We conclude that increased intracellular calcium in primary HPT and essential hypertension seems to depend on an increased inflow through specific channels. However in primary HPT, this alteration is related to PTH levels.

Analysis of Variance↗
PubMed1994

Primary hyperparathyroidism and hypertension: persistently abnormal pressor sensitivity in normotensive patients after surgical cure.

To examine the effects of primary hyperparathyroidism separately from those of hypertension per se on blood pressure regulation in patients with primary hyperparathyroidism, we studied the pressor response to infused angiotensin II (AII) and to norepinephrine (NE) in 7 normotensive patients with primary hyperparathyroidism before and after surgical cure, and compared it to that observed in 10 subjects with idiopathic hypertension and 10 normal controls. While the subjects were on an ad libitum diet, we measured urinary and plasma electrolytes, creatinine, and plasma renin activity. Except for calcium, these values were not significantly different among the three groups. The blood pressure was measured basally and in response to graded doses of AII or of NE until a 20-mmHg increase in the diastolic blood pressure was reached ("pressor dose"). The pressor doses of AII and of NE were lower in the normotensive patients with primary hyperparathyroidism than in normal controls [4.6 +/- 2.0 vs. 7.3 +/- 3.5 ng/kg/min (p < 0.05) and 164 +/- 114 vs. 302 +/- 176 ng/kg/min (p < 0.05) respectively] and not significantly different from those found in idiopathic hypertension (3.1 +/- 1.2 and 137 +/- 95 ng/kg/min). When the patients with primary hyperparathyroidism were studied again between 2-6 months after surgical cure, their pressor doses of AII and of NE remained unchanged from their preoperative values (5.4 +/- 2.9 and 137 +/- 80 mg/kg/min). We conclude that the hyperparathyroid condition can disrupt the normal responsiveness to pressor agents even if the blood pressure remains within normal limits, and that this abnormality may persist after surgical cure.

Adult↗
PubMed1994

[Importance of the deficit of crystallization inhibitors in the etiopathogenesis of urolithiasis].

BACKGROUND: five percent of consultations at the Emergency Room of Catholic University Hospital are due to nephrolithiasis. The causes of this high frequency remain unknown. AIM: to know the main metabolic and anatomic factors involved in the genesis of neprholithiasis. PATIENTS AND METHODS: forty one patients (31 male) were studied presenting with a renal colic were studied as soon as the acute episode subsided and without diet modifications. Fasting blood calcium and creatinine and 24 h urine calcium, uric acid, citrate, magnesium and pH were measured and an intravenous pyelogram was performed. Twenty one subjects without a history of nephrolithiasis were used as controls. RESULTS: Patients with nephrolithiasis did not differ from controls in urinary calcium (159 +/- 67 and 172 +/- 67 mg/24 h respectively), uricosuria (417 +/- 171 and 431 +/- 121 mg/24 h respectively) or urinary magnesium (55 +/- 19 and 62 +/- 21 mg/24 h respectively, whereas urinary citrate was lower (219 +/- 172 vs 319 +/- 179 mg/24 h in controls p < 0.05). All patients had normal renal functions, urinary acidification and intravenous pyelogram. Seven percent of patients with nephrolithiasis had hypercalciuria, 2.4% had hyperuricosuria. 68.3% had a low urinary citrate and 44.4% had low urinary magnesium. CONCLUSIONS: in this sample, there is a strong association of nephrolithiasis with low levels of crystallization inhibitors in special with urinary citrate, a crystallization inhibitor.

Adult↗
PubMed1993

[Autoimmune thyroid disease diagnosed during puerperium: evaluation 2 years later].

This is a 2 years follow-up study of seventeen women who were found to have mild goiter and post-partum thyroid disease two years earlier in order to establish if post-partum thyroid disease is a self-limited entity or the relapse of a chronic pre-existing disease. When first studied, the 17 women had thyroid dysfunction (15 with hyperthyroidism and 2 with hypothyroidism). Eight women had also elevated antimicrosomal antibodies (AMA) titers and 9 were negative for AMA. In the present study, all women were reexamined for the presence of goiter, and free thyroxine index (FT4I), TSH and AMA were determined. Mild (grade I-II, less than 30 g) goiter was found in 11 women. Six out seventeen women, still had altered functional tests (3 with hypothyroidism and 3 with hyperthyroidism). The elevated AMA titers seen in 8 patients in the first study, remained high in 6 (1:100-1:25600). None of the 9 patients who in the first study had negative AMA changed to positive titers. Results indicate that post-partum thyroid disease is not always a self-limited entity. The presence of elevated AMA titers in the initial post-partum period can express a chronic thyroid disease compromise. In these patients a longterm clinical and biochemical follow-up is recommended.

Autoantibodies↗
PubMed1993

[Hemolysis induced by Loxosceles laeta venom. In vitro experience].

To study the effects of loxosceles laeta venom on red blood cells and the possible factors involved in hemolysis during arachnidism, in vitro models were designed to measure the role of loxosceles venom, calcium, complement and antibodies in the mechanism of red blood cell destruction. The degree of basal hemolysis was measured in a 5% suspension of group O, Rh (+) red blood cells in pH 7.4 buffer. In a similar suspension spider venom was added in amounts equivalent to one venom gland. After 72 hours of incubation, basal hemolysis was 5.59 +/- 2.04% which increased to 26.01 +/- 7.9% adding venom (p < 0.001). Adding calcium to the incubation medium, hemolysis increased to 88.5 +/- 7.16% (p < 0.001). Incubating red blood cells with control human serum and venom, hemolysis was 14.58 +/- 2.42%, which decreased significantly to 6.85 +/- 3.35% when serum was heat inactivated; this demonstrates an effect of the presence of complement. We did not find antivenom antibody production in patients with arachnidism 10, 15 or 30 days after the spider bite. It is thus demonstrated that loxosceles laeta venom has a direct lytic action on red blood cells that is calcium and complement dependent and is not mediated by antibodies or other substance.

Animals↗
PubMed1990

Autoimmune thyroid disease in the puerperium. Predictive value of thyroid enlargement and related hormonal changes occurring during pregnancy.

The incidence of goiter detected during pregnancy and its significance as an indicator of autoimmune thyroid disease after delivery was investigated in a sample of 707 pregnant women (81% in their 2nd trimester of gestation). Goiter was detected in 106 subjects (15%). Blood T4, T3, TSH, free T4 index (FT4I), antimicrosomal antibodies (AMA) and urinary iodine excretion were measured in these women and in a control group of gravidas without goiter. These measurements were repeated at 1 and 3 months after delivery. Compared with controls during pregnancy, subjects with goiter had lower FT4I values (11.0 +/- 2.8 vs 9.0 +/- 1.8; p less than 0.01) and higher TSH values (2.9 +/- 0.6 microU/ml vs 4.2 +/- 2.1 microU/ml; p less than 0.01). In contrast, T4, T3, AMA and urinary iodine excretion values were similar in both groups. In subjects with goiter FT4I values increased over pregnancy levels at 1 month (11.2 +/- 2.0; p less than 0.05) and 3 months (14.0 +/- 3.0; p less than 0.05) after delivery; in 29% a biochemical hyperthyroidism (FT4I greater than 13.5) was detected. During the same period TSH values decreased significantly (1 month: 1.9 +/- 0.7 microU/ml; p less than 0.05; 3 months: 2.7 +/- 3.0 microU/ml; p less than 0.05). Frequency of positive AMA increased from 8.6% during pregnancy up to 32.1% in the post-delivery period (p less than 0.01). In the control group no variation in the FT4I, TSH or AMA were observed after delivery. These results indicate that goiter during pregnancy is common in Chilean gravidas and that it has predictive value for the appearance of autoimmune thyroid disease after delivery.

Adolescent↗
PubMed1989

[Primary hyperparathyroidism: usefulness of high resolution echography in local diagnosis].

Recent reports show a better surgical outcome in primary hyperparathyroidism when an accurate preoperative localization of the lesion in available. We performed high resolution sonography in 23 consecutive patients (20 women) with biochemically proven hyperparathyroidism. Twenty two of them were operated on and their sonographic reports were compared to the surgical and pathological findings (20 adenomas, 1 carcinoma and 1 hyperplasia). One patient did not have surgery but the sonogram was compared to a Tl 201-Tc99 scintigram that suggested an adenoma. Sonography showed a single parathyroid tumor in 17 patients and failed to demonstrate a lesion in six. There were two false positives and 6 false negatives. The sensitivity was 71.5% and the positive predictive value was 88%. Three out of 6 patients with a negative sonography had an adenoma located out of reach for the method. Our results show that the high resolution sonography is a useful, non invasive method to localize abnormally enlarged parathyroid glands in hyperparathyroidism and we think it should be performed in every patient with a biochemical diagnosis of this disease.

Adult↗