Biomedical subjects

H C Hoeck

Publications and source records attributed to H C Hoeck.

6 recordsLinked to original sources

PubMed1995

Test of growth hormone secretion in adults: poor reproducibility of the insulin tolerance test.

The insulin tolerance test (ITT) is regarded as the most reliable provocative test in the diagnosis of growth hormone (GH) deficiency in adults. In the present study the test was evaluated by investigating the range of GH responses in normal adult males and females and the intra-individual reproducibility of the test. Sixteen healthy non-obese adults, eight males (median age 31.5 years) and eight females (median age 31.8 years) were tested twice with the ITT, with a minimum of 72 h between each test. The females were tested between day 3 and day 10 of their menstrual cycles. Adequate hypoglycemia was achieved in all cases with a median nadir blood glucose of 1.3 mmol/l (range 0.8-2.0). Growth hormone in serum was measured by immunoradiometric assay and low values were confirmed by a different assay. Median peak GH concentration responses to the ITT were: in males 27.9 micrograms/l, range 5.0-71.1 (test 1) and 30.5 micrograms/l, range 7.9-69.5 (test 2); and in females 9.0 micrograms/l, range 4.1-17.9 (test 1) and 8.4 micrograms/l, range 0.09-42.4 (test 2). The rise in GH concentration during the ITT was higher in males than in females. In the males, all stimulated GH values were > or = 5.0 micrograms/l. In the females, four out of 16 tests gave values below 5.0 micrograms/l and in one test the GH value was around the detection limit of the assays. There was poor reproducibility during repeated testing, with no correlation between the results of the two tests. The results did not correlate to the magnitude of the hypoglycemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

[Abnormal flora in the small intestine. Diagnostic evaluation of the H2 breath test].

Jejunal aspiration in order to diagnose intestinal bacterial overgrowth is more unpleasant for patients than breath testing. The object of this study was to compare the results of the glucose H2 breath test and the lactulose H2 breath test with the results of intestinal culture. On separate days, cultures of intestinal fluid collected from the Treitz region, glucose H2 breath tests (80 g glucose) and lactulose H2 breath tests (15 g lactulose) were undertaken in 20 patients with diseases predisposing to small intestinal bacterial overgrowth and in 20 controls. Twelve patients had bacterial overgrowth. Abnormal glucose H2 breath tests were observed in 11 patients, ten of whom had bacterial overgrowth. Glucose H2 breath tests were normal in seven out of eight patients without bacterial overgrowth. Only four patients had an abnormal lactulose H2 breath test. It is concluded that the glucose H2 breath test is acceptable for diagnosing bacterial overgrowth, whereas the lactulose H2 breath test in not.

Adult↗

PubMed1994

Hypercalcaemic crisis after excessive topical use of a vitamin D derivative.

Topical application of the vitamin D analogue calcipotriol has been found to be of clinical value in the treatment of dermatological disorders. This is considered to be safe with respect to alterations in calcium homeostasis. We report a 17-year-old female patient who developed hypercalcaemic crisis after excessive use of calcipotriol for ichthyosis. The clinical condition and serum calcium improved after cessation of calciprotiol treatment and rehydration with intravenous fluids and electrolytes. The case emphasizes the importance of limiting the topical use of calcipotriol as recommended by the manufacturer.

Acitretin↗

PubMed1994

Growth hormone and thyroid function: is secondary thyroid failure underdiagnosed in growth hormone deficient patients?

Thyroid hormones and the GH/IGF-1 system show considerable mutual interference which may have physiological, pathophysiological and clinical importance. GH therapy of children and adults may induce a fall in serum T4, which seems to be due to an effect on the deiodination of T4 to T3. Animal studies suggest that the alterations in thyroid hormones in tissue may be much more prominent than the changes observed in serum. It is possible that the GH deficiency seen in the majority of patients with pituitary/hypothalamic disorders may mask secondary hypothyroidism in some patients by giving a relatively high serum T4. GH therapy may then unmask the hypothyroidism. In accordance with such a mechanism GH deficient children evaluated thoroughly to exclude secondary thyroid failure before GH administration do not develop thyroid insufficiency during GH substitution therapy. It is suggested that thyroid insufficiency should be considered in GH deficient patients with low normal serum T4.

Adult↗

PubMed1994

Impaired growth hormone secretion in patients operated for pituitary adenomas.

The frequency of growth hormone (GH) deficiency in patients operated for pituitary neoplasms of various size and type was investigated using the insulin tolerance test. 45 patients were included in the study. 20 of the patients had a non-hormone secreting pituitary neoplasm, 9 had GH-, 6 ACTH-, 7 prolactin secreting adenomas and 3 had a craniopharyngeoma. Complete endocrinological examination was obtained in all patients after pituitary surgery. Apart from patients operated for GH secreting adenomas, GH deficiency was very common after pituitary surgery (92%), even in patients operated for small lesions. Among the 45 patients LH/FSH deficiency was found in 33%, ACTH in 33%, TSH in 18% and ADH deficiency in 9% of the patients. In this study, impaired GH secretion was found to be independent of the size of the tumors and was present in nearly all patients after pituitary surgery (with exception of GH secreting adenomas). Deficiencies of other pituitary hormones were predominantly observed after surgery for large tumors.

Adenoma↗

PubMed1990

[Transient abnormal Q-waves].

We present a case of transient abnormal Q-waves (TAQ) and a review of the literature. TAQ are defined as abnormal Q-waves, which disappear within ten days. They are most often seen in patients with ischemic heart disease (IHD) but are also seen in other conditions. Brief episodes of myocardial ischemia giving rise to reversible biochemical and ultrastructural myocardial changes, resulting in transient ECG changes, provide an accepted theory for the pathogenesis of TAO. Investigations have shown that the occurrence of exercise-induced TAQ may be a symptom of IHD. It is impossible to distinguish TAQ from Q-waves induced by myocardial infarction. Appearance of TAQ during exercise-testing frequently indicates IHD.

Arrhythmias, Cardiac↗