Serum calcium and parathyroid function linked to control of respiration.

It is suggested that the plasma concentration of ionized calcium in a complex way is connected to control or respiration in mammals. The level of ionized calcium in plasma is suggested to correlate with the arterial carbon dioxide tension as well as with the arterial oxygen tension. The primary function of the parathyroid glands, which are absent in fish, but develop in land vertebrates, is suggested to be control of plasma calcium and pH in respiratory alkalosis due to hyperventilation.

The basis for common reference intervals for serum potassium.

In order to investigate the relevance of the currently used lower reference limit for S-Potassium in Danish hospital laboratories, analytical bias in the measurement of S-Potassium was compared with the lower reference limit in each of 52 Danish hospital laboratories. The acceptable bias range was estimated according to Gowans et al on the basis of the result of two different reference sample groups. The estimated acceptable 0.95 bias range was 0.24 mmol/L, so the observed bias range of 0.23 mmol/L was within this limit. As all preanalytical errors tend to increase the measured S-Potassium, all acceptable bias should be in the direction of decreasing the measured value. It can be concluded that analytical performance allows for more uniform (even common) reference interval(s) in all Danish and perhaps Nordic hospital laboratories, provided that preanalytical errors can be controlled.

[Calcium blood changes in septic conditions. A review]. / Calciumaendringer i blodet ved septiske tilstande. En oversigt.

Hypocalcemia has been reported in critically ill patients over the last 10-15 years, however, measurements of Ca2+ in blood have not yet became routine in the treatment of severely ill patients. In order to stress the importance of calcium in such patients, a review of calcium changes in septic conditions is presented. In vitro studies show that the intracellular calcium metabolism is disturbed in these patients, and that the changes in extracellular calcium are probably secondary to the intracellular changes. Parathyroid hormone secretion is inappropriate in septic patients. The reason for this is unknown. Administration of calcium parenterally does not seem to affect the prognosis, however calcium seems to be beneficial in patients with hypotension. Since the level of Ca2+ in blood may have prognostic significance in septic patients, measurements of Ca2+ in blood should be used routinely in these patients, in order to point out "risk" patients as early as possible.

[RTH syndrome--resistance to thyroid hormone syndrome]. / RTH-syndromet--resistance to thyroid hormone syndrome.

The RTH syndrome is an instructive example of a receptor resistance syndrome. A typical case history is reported here. The patient had had symptoms for many years and was first diagnosed as having inappropriate secretion of TSH. Pituitary tumour was excluded. The primary symptom was palpitations and the patient was partially thyroidectomized many years ago on suspicion of thyrotoxicosis. She was then given substitutional Eltroxin, but, because of palpitations, the dose was reduced to almost zero, after which the patient contracted symptoms suggesting myxoedema. The thyroid values could not be used for clinical assessment, however the symptoms of myxoedema disappeared when the Eltroxin dose was increased to 75 micrograms/day. When the dose was increased further the heart symptoms became too troublesome. The patient had no signs of underlying heart disease.

[DiGeorge syndrome. Velocardiofacial syndrome/chromosome 22q11 deletion syndrome]. / DiGeorges syndrom. Velokardiofacialt syndrom/kromosom 22q11-deletionssyndrom.

Patients with a deletion of chromosome band 22q11 are described as having DiGeorges syndrome, velocardiofacial syndrome or chromosome 22q11 deletion syndrome depending on clinical manifestations. The patients have variable severity and combinations of conotruncal heart defects, abnormalities of the ear and palate, facial dysmorphism and mental retardation as well as partial or complete aplasia/hypoplasia of the thymus and endocrine dysfunction, e.g. hypoparathyroidism. The patients may present with impaired immune function, heart failure, hypocalcaemia, facial dysmorphism, impaired hearing and mental retardation. The syndrome, which is a significant cause of heart and craniofacial defects as well as mental retardation, is probably underdiagnosed. In each of the above mentioned phenotypical presentations, chromosome 22q11 deletion syndrome should be considered.

[DiGeorge syndrome diagnosed in a 39-year old woman with chronic hypocalcemia]. / DiGeorges syndrom diagnosticeret hos en 39-årig kvinde med kronisk hypokalcaemi.

A 39 year-old woman was diagnosed with DiGeorge's syndrome based on newly diagnosed hypocalcaemia, appearance and history. The patient had congenital cardiovascular malformations, mild mental retardation and ear malformations, and during infancy and childhood suffered from failure to thrive and frequent infections. In children with conotruncal heart malformation, hypocalcaemia and hypoplasia of the thymus in combination it is estimated that chromosome 22q11 deletion is present in almost 100%. The syndrome is probably underdiagnosed.

[The effect of beta blockers combined with thiazides on serum electrolytes]. / Virkningen af beta-blokkere kombineret med tiazider på serumelektrolytter.

The case reports of a total of 9,670 patients admitted to a medical department were reviewed manually. From this material, all patients receiving treatment with beta-blockers alone, bendroflumethiazide alone or combinations of these were selected. In addition, a control group was selected. The patients should have received treatment for at least seven days and they should not be "ill". Patients receiving treatment with beta-blockers had higher S-K+ (4.2 mmol/l) and lower standard bicarbonate levels (23 mmol/l) than matched controls. Patients receiving treatment with bendroflumethiazide had low S-K+ (3.6 mmol/l) and high standard bicarbonate (26 mmol/l). Patients receiving treatment with both bendroflumethiazide and beta-blocker had low S-K+ (3.4 mmol/l) and the same standard bicarbonate as patients who received bendroflumethiazide alone. A more limited group chosen according to stricter criteria confirmed the above mentioned results. The investigation demonstrated that treatment with both beta-blocker and bendroflumethiazide caused deterioration of the hypokalaemia induced by bendroflumethiazide despite the higher S-K+ during beta-blockade. This may be due to renal excretion of potassium during beta-blockade.

[A 7-year experience with goiter surgery in an otorhinolaryngologic department. A retrospective study of the the period 1990-1996]. / Syv års erfaring med strumakirurgi i øre-, naese- og halsregi. En retrospektiv undersøgelse fra 1990 til 1996.

The aim of this study was quality assurance and to analyse the frequency of complications following thyroid surgery. The most dreaded surgical complications are permanent injury to the recurrent laryngeal nerve or persistent hypocalcaemia. Our surgical procedure included the use of the surgical microscope in connection with thyroid grand surgery. Our materiel includes 122 patients who underwent surgery for benign thyroid diseases in our department from 1990-1996. In nearly 50% of all cases a lobectomy was performed, reserving resections and subtotal thyroidectomy to special cases. Resections were primarily done in the beginning of the period. The surgical microscope was used as a standard procedure to identify and expose the recurrent laryngeal nerve and the parathyroid glands. Primary thyroid grand surgery in benign disease resulted in permanent unilateral laryngeal nerve palsy in one case or in 0.83% of the patients. When calculated as nerves at risk, the complication rate was reduced to 0.67%. In benign completion surgery the complication rate was 0%. No patient developed persistent hypocalcaemia.

Comparative aspects of iodine conservation in mammals.

1. Comparative aspects of iodine conservation in mammals were studied on the basis of published data on kidney and thyroid weights and function. 2. Very small mammals possessed an efficient reabsorption of iodide to compensate for the high glomerular filtration rate (GFR). 3. Humans and mammals of a similar and larger size had "lost" the ability to reabsorb iodide efficiently. 4. Very large mammals are protected against renal loss of iodide due to the relatively low GFR. 5. Thyroid weights in relation to body weight were highest in humans suggesting that humans and other mammals of a similar size are especially susceptible to iodine deficiency.

Subnormal alanine aminotransferase values in blood of patients with Crohn disease.

BACKGROUND: It was observed that several patients from the outpatient clinic with Crohn disease (CD) occasionally had subnormal values of alanine aminotransferase (ALAT) in blood. Subnormal ALAT values have previously been reported only in renal failure. METHODS: A retrospective study of clinical chemistry values going back 10 years was conducted in all patients from the outpatient clinic with CD or ulcerative colitis (UC). Exclusion criteria were age >50 years, a daily alcohol consumption, known liver disease or other chronic diseases with a possible effect on liver function (n=42). The remaining patients (n=123) were classified as UC, CD or indeterminate colitis (ID). Eight patients with microscopic colitis (MC) were also included. RESULTS: It was found that 49/50 CD patients had subnormal ALAT on one or several occasions (mean 7 U/L, range 5-9). Only 1/67 patients with UC had subnormal ALAT values. The mean ALAT value in UC was 20 U/L, range 10-40. In IC, 5/6 patients had subnormal ALAT. None of the 8 patients with MC had subnormal ALAT. CONCLUSIONS: The demonstration that subnormal ALAT values are almost entirely seen in CD as compared with UC may have clinical importance and adds to the information on the pathophysiological differences between these two diseases.

A comparison of the effect of TSH, GH and prolactin on the renal iodide excretion in unrestrained rabbits.

The immediate effect of graded iv doses of heterologous TSH, GH and prolactin on the renal iodide excretion was sutdied in unrestrained rabbits with implanted Geiger Müller detectors. Both TSH and GH lowered the fractional excretion rate of iodide. The duration of the effect was significantly correlated to the magnitude of the administered dose. The lowest dose with a significant effect was 10-20 mU TSH and 50 mU GH. Prolactin had no similar effect even in high pharmacological doses. An effect similar to that of small TSH doses was recorded following administration of 20-40 microng TRH iv. The immediate effect of GH on the iodide excretion accords with previous reports about similar effect on sodium excretion and suggests, that the effect of GH and TSH on the iodide excretion is secondary to a general effect on kidney function. The demonstration, that the effect is present in unrestrained animals after administration of physiological doses indicates, that the effect is not only of pharmacological significance, but may also have physiological significance.