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S Almqvist

Publications and source records attributed to S Almqvist.

At least 19 recordsLinked to original sources
PubMed1983

Thyroid hormone secretion rates: response to endogenous and exogenous TSH in man during surgery.

The thyroid hormone secretory response to TSH was studied in twenty-eight patients undergoing thyroid and parathyroid surgery. Eighteen patients received bovine or human exogenous TSH by injection into a thyroid artery, and 10 received TRH to stimulate endogenous TSH secretion. Thyroid secretion rates of T4, T3, and rT3 were determined directly from measurement of blood flow and the hormone gradient across the gland. A significant secretory response was seen for all three hormones following TSH increase. T3 secretion accelerated more rapidly than that of T4 and rT3, thus reducing the T4/T3 and rT3/T3 ratios. The T4/rT3 ratio fell during the first 30 min but then increased. The responses correlated with the area under the curve of the TSH serum concentration, and were similar after administration of bovine and human exogenous TSH, and TRH. Conclusions regarding preferential secretion ought to be made by comparing ratios of thyroid hormone secretion with those of the hormone content of the gland, but our results indicate that TSH induces preferential secretion of triiodothyronines in man.

Adult↗
PubMed1982

Secretion rates of thyroxine, triiodothyronine, and reverse triiodothyronine in man during surgery.

The secretion rates of T4, T3, and rT3 were studied in experiments of short duration by a new method based on determinations of the hormone difference across the thyroid combined with simultaneous electromagnetic thyroid blood flowmetry during surgery in 70 euthyroid patients. The secretion rate of T3 was similar in normal thyroid tissue and nodular goitre, but those of T4 and rT3 were lower in nodular goitre and solitary adenoma (P less than 0.05). In 61 patients with normal thyroid tissue or nodular goitre the secretion rates during surgery (mean +/- SEM) were for T4 222 +/- 28 nmol/day, for T3 27.4 +/- 3.1 nmol/day, and for rT3 3.5 +/- 0.5 nmol/day. In relation to the individual T4 secretion rate, the secretion rate of T3 was 12.5 +/- 3.0% and that of rT3 1.2 +/- 0.9%. In these short-term experiments we found a secretion rate for T4 during operation about 50% greater than in earlier long-term kinetic studies, but which tallied with a recent report using a 4-compartment model. For T3 and rT3 it was 2-3 times greater than earlier estimates. The secretion was estimated to be 50% of the total production rate for T3 and 6% for rT3. If proportional adjustment were performed to yield a T4 secretion of about 130 nmol/day. T3 and rT3 secretion rates would still be greater than earlier reported.

Adenoma↗
PubMed1980

Vitamin D deficiency in welfare institutions for the aged.

Serum concentrations of 25-OH-D in a group of 47 elderly people (70--94 years old) living in homes for the aged were lower than those in a matched control group living in their homes. No differences between the groups were noted in serum ionized calcium, alkaline phosphatase, inorganic phosphate, magnesium or parathyroid hormone. The low serum concentration of 25-OH-D may be due to less outdoor activities and/or a smaller dietary vitamin D intake in the institutionalized group. The importance of preserving an adequate vitamin D status in geriatric patients is emphasized.

Aged↗
PubMed1979

Non-selective and selective beta-1-adrenoceptor blocking agents in the treatment of hyperthyroidism.

Treatment for one month with propranolol or atenolol, a selective beta-1-adrenoceptor blocking agent, was evaluated in 20 hyperthyroid patients. The patients improved to the same extent on either drug, as shown by a clinical diagnostic index. Basal metabolic rate decreased by 11% during both treatments, while it was unchanged in seven untreated hyperthyroid controls. Thyroxine concentration did not change during any treatment. During propranolol treatment T3 decreased from 4.6 to 3.9 nmol/l, while no changes were observed during atenolol treatment or in the control group. No significant changes were seen in free T4, free T3 or rT3 concentrations on any treatment, although free T3 was observed to decrease slightly during propranolol treatment. Thus, the improvement of the clinical symptoms of hyperthyroidism cannot be explained by diminished thyroid hormone concentrations in serum, since the reduction was small during propranolol and absent during atenolol treatment.

Adolescent↗
PubMed1978

Salmon calcitonin in the acute treatment of moderate and severe hypercalcemia in man.

The effect of i.v. infusions with salmon calcitonin was evaluated in the treatment of acute hypercalcemia in 12 patients. Clinical improvement and a less critical level of serum calcium were achieved within 24 hours for eight of the patients, for another two after treatment for 48 hours. In malignant conditions (six patients) calcitonin was less effective, which could be evaluated within 24 hours. In addition to rehydration, the rapid onset of action and the lack of side-effects make calcitonin a drug of first choice in the treatment of acute hypercalcemia.

Acute Disease↗
PubMed1978

Somatostatin inhibits the pentagastrin-induced release of serum calcitonin in medullary carcinoma of the thyroid.

The effect of somatostatin on the secretion of calcitonin was studied in four patients with medullary carcinoma of the thyroid (MCT). The basal serum calcitonin level was markedly elevated in all cases. A bolus injection (100 microgram) of somatostatin followed by an intravenous infusion (5 microgram/min) for 60 min suppressed the basal calcitonin level in three of the four patients by 24-42%, while it had no inhibitory effect in one case. In another experiment, the pentagastrin-stimulated (6 microgram/kg s.c.) calcitonin release was partially blocked by a simultaneous i.v. injection of somatostatin (200 microgram) in all four patients studied. These experiments add human calcitonin to the list of hormones whose release in inhibited by somatostatin.

Adult↗
PubMed1977

Screening for medullary carcinoma of the thyroid in families with Sipple's syndrome: evaluation of new stimulation tests.

In search of new practical diagnostic methods for the early diagnosis of hereditary medullary carcinoma of the thyroid (MCT) calcitonin release has been studied following induction by pentagastrin, cholecystokinin-pancreozymin (the C-terminal octapeptide, C8-CCK, and the native swine extract), and ethanol in eighteen cases of MCT (all but one clinically occult), three 'borderline cases', seven first degree relatives of patients with hereditary MCT and thirty-five healthy controls. Pentagastrin, subcutaneous (s.c.) or intravenous (i.v.), induced a pronounced and rapid increase of serum calcitonin within 2-5 min. The elevation was roughly proportional to the tumour mass as estimated at operation. Seventeen out of eighteen MCT patients responded to s.c. pentagastrin with a significant increase in serum calcitonin and the response correlated well with that induced by calcium infusion test. Only two blood samples, at times 0 and 5 min, were necessary for diagnosis. In the MCT patients, i.v. pentagastrin produced more pronounced elevations of serum calcitonin than did s.c. pentagastrin, whereas no increase was seen in the control group. The subjective discomfort caused by i.v. pentagastrin was somewhat more intense but lasted shorter than that induced by s.c. administration. No serious complications were seen. All of nine MCT patients responded to C8-CCK with increments in serum calcitonin exceeding those of the control group and both of two responded similarly to the native cholecystokinin-pancreozymin extract. Generally the serum calcitonin response was lower and more variable after C8-CCK than after s.c. or i.v. pentagastrin, and the subjective discomfort was also more pronounced with abdominal cramps during the injection. Ethanol in the dose used was the least effective stimulator for serum calcitonin release. Clinically suspected MCT carriers with palpable tumours can be diagnosed by determination of the basal, i.e. non-stimulated serum calcitonin levels. Other possible Sipple genome carriers, who are at the time clinically healthy with normal basal serum calcitonin, should be subjected to a s.c. or i.v. pentagastrin stimulation test at each examination. These tests are much simpler to perform than a calcium infusion, test, but seem to have about the same sensitivity.

Adolescent↗
PubMed1975

Serum calcitonin response to induced hypercalcemia.

The rise in serum calcitonin (delta-CT240 min) has been measured during hypercalcemia induced by i.v. infusion of calcium gluconate. This calcium infusion test was used in a prospective screening for medullary carcinoma of the thyroid (MCT) in 4 families with Sipple's syndrome as well as in 3 sporadic cases of MCT. In 16 normal controls delta-CT240 was minus 0.2-+ 0.5 ng/ml (mean plus or minus 2 S.D.). Delta-CT240 was normal in 2 patients with chronic hypocalcemia. In all 14 MCT patients delta-CT240 was markedly higher (min-max 2.2-630 ng/ml), i.e. no false negatives were found. However, in these cases, the diagnosis was already evident from basal serum calcitonin (S-CT), which up to now has been our most sensitive diagnostic technique for MCT. 19 first-degree relatives of patients with Sipple's syndrome presented no signs of MCT. In 14 of these delta-CT240 was normal ("healthy relatives"), but in 5 it was slightly elevated, intermediate between the controls and the MCT patients. These 5 borderline cases were more sharply delineated from normal by delta-CT240 than by S-CT. Thus our calcium infusion test seems to be the most sensitive method for early diagnosis of occult MCT. We recommend the calcium infusion test for: (a) screening for MCT in all Sipple relatives with normal or only slightly elevated basal S-CT, (b) postoperative control in both sporadic and hereditary MCT, (c) investigation of supposed non-MCT tumours with calcitonin production.

Adolescent↗
PubMed1975

The diagnostic value of a radioimmunoassay for parathyroid hormone in human serum.

A radioimmunoassay for the measurement of immunoreactive parathyroid hormone (PTH) in human serum is described. The assay is based on the ability of human parathyroid hormone (h-PTH) to compete with 125I-labelled bovine parathyroid hormone (b-PTH) for binding to a guinea-pig antiserum directed against b-PTH. The linear part of the standard curve was parallel with dose response curves for anti-b-PTH serum reacting with dilutions of sera from patients with primary hyperparathyroidism and from h-PTH purified from human parathyroid adenomas, indicating that levels of immunoreactive PTH could be expressed as b-PTH equivalents. The range in 62 healthy blood donors was 1.1-2.5 ng b-PTH Eg./ml. The reproducibility was satisfactory, and the sensitivity permitted the measurement of PTH concentrations down to 0.8 ng b-PTH Eg./ml. No crossreaction with h-CT, h-STH or h-ACTH was observed. The clinical value of the assay has been considered in a number of patients with various disorders of calcium metabolism, diagnosed and treated conventionally. About 80 per cent of patients with primary hyperparathyroidism had elevated PTH levels on one or more occasions before surgery. In patients with chronic renal failure of other aetiology than primary hyperparathyroidism the levels were usually far higher. Patients with primary hyperparathyroidism and increased S-creatinine had higher PTH levels than those with normal S-creatinine. After parathyroidectomy all previously increased PTH levels became normal or low. High PTH concentrations were found in 3 patients with normocalcaemic hyperparathyroidism who at operation were shown to have parathyroid adenomas. However, in normocalcaemic patients there were also some falsely elevated PTH values which limit the diagnostic value of the assay in this group of patients. Low PTH values were observed in patients with hypercalcaemia due to malignant disorders, indicating that PTH determination may be of some value in the diagnosis of patients with hypercalcaemia of unknown origin.

Adult↗
PubMed1975

Pre-operative localization of parathyroid tissue by selective neck vein catheterization and radioimmunoassay of parathyroid hormone.

Preoperative localization of parathyroid tissue by selective neck vein catheterization and radiommunoassay of parathyroid hormone (PTH) was used in 18 patients with primary hyperparathyroidism (PHPT), 9 or whom had earlier been subjected to surgical neck exploration. Sampling from large and small neck veins provided localizing data in 11 of 15 patients with parathyroid adenomas. In 3 other patients, diffuse parathyroid hyperplasia was also correctly predicted preoperatively. In 3 patients hyperplasia was found, the surgical procedure was not influenced in a negative way by the failures. Large vein sampling was less helpful then selective small vein sampling. The results show that selective venous sampling from the neck and radioimmunoassay of PTH are valuable preoperative adjuncts to surgical exploration, escpecially in patients who have had previous neck surgery. Since the catheterization procedure is uncomfortable to the patient and difficult for the investigator, its use should be restricted to patients with previous neck surgery, Neck vein catheterization can probably not be used to establish the diagnosis of PHPT in uncertain cases.

Adenoma↗