Serum galactosylhydroxylysyl glucosyltransferase in acute myocardial infarction and during subsequent collagen scar formation

Changes in serum galactosylhydroxylysyl glucosyltransferase, an enzyme catalysing one of the intracellular post-translational modifications in collagen biosynthesis, were studied in twenty-four patients with acute myocardial infarction. The enzyme activity was monitored for 18 days from the onset of infarction, and at least a two-peaked pattern was observed. The first peak corresponded to the stage of acute myocardial injury, there being a highly significant correlation between the maximal values for serum glucosyltransferase and alpha-hydroxybutyrate dehydrogenase. An average decreasing in serum glucosyltransferase activity of 41%, was noted during the following 24 h. A new gradual rise in serum glucosyltransferase activity, interpreted as indicating myocardial collagen scar formation, was observed 5 days after the onset of infarction, when the serum enzyme activities indicating myocardial injury had already declined. The average daily values for serum glucosyltransferase between 6 and 18 days correlated highly significantly with the maximal value for serum alpha-hydroxybutyrate dehydrogenase, which serves as a relative estimate of the size of the original myocardial infarction area. The data further suggest that certain other factors including heart failure and/or various drug treatments may also affect the magnitude of this second peak.     

DISCREPANCY BETWEEN ACTH AND CORTISOL RESPONSES TO INSULIN INDUCED HYPOGLYCAEMIA

The purpose of this study was to assess the normal relationship between plasma ACTH and cortisol during insulin induced hypoglycaemia. Twenty-six healthy persons were studied. Peak plasma concentration and the amounts of ACTH and cortisol secreted during hypoglycaemia were compared. There was no significant correlation between the ACTH and cortisol values. The ACTH responses varied significantly more than those of cortisol. This probably signifies an over-capacity of ACTH secretion in comparison to the secretory capacity of the adrenal cortex.     

External pressure-blood flow relations during limb compression in man

The effect of increased tissue pressure on blood flow in subcutaneous and skeletal muscle tissue was studied in 8 healthy humans resting in horizontal position. Blood flow was measured by the local ¹³³Xe washout technique in the mid-calf region. Tissue pressure in the depot area was increased by inflating a compression cuff, 50 cm wide (knee to ankle). Blood flow rates were obtained from compressed tissues with normal vasomotor tone, at papaverine-induced vasoparalysis and during distension of the compressed vessels. The latter was achieved by inflating a proximal (extra) compression cuff on the thigh 10 or 20 mmHg above the pressure level in the more distally placed compression cuff. Increased tissue pressure was a potent stimulus for arteriolar dilatation (autoregulation) in both tissues. The autoregulatory response was to some extent counteracted by an increase in local vascular resistance in the postcapillary section as evidenced by the results of simultaneous venous stasis. Blood flow ceased in vasoparalysed tissues as well as in tissues with normal vasomotor tone, when the compression cuff was inflated to the level of the local diastolic blood pressure. Maintaining external compression at the diastolic blood pressure level, blood flow reappeared in both tissues, when the compressed vessels were distended by adding the proximal (extra) compression. It is concluded, that blood flow cessation in compressed tissues is caused by a widespread arterial-arteriolar collapse in diastole, as the volume of blood injected during the systolic peak is too small to expand also the distal sections of the precapillary vessels.     

The effect of vasodilatation and sympathetic nerve activation on net water absorption in the cat's small intestine

The rate of net water uptake from the feline small intestine has been investigated during control conditions, during graded infusions of the vasodilator drug isopropylnoradrenaline, and during electrical stimulation of the regional sympathetic nerve fibres to the gut. Net water absorption rate was largely unaffected by intestinal vasodilatation. The fraction of the absorbate transported via the lymphatics remained also constant at 20–40% of the total absorption regardless of blood flow rate. Stimulating the sympathetic nerve fibres to the small intestine increased, however, net water absorption rate. The increase was particularly pronounced when blood pressure was kept constant during the period of stimulation. The absorption rate was on an average almost doubled at a stimulation frequency of 8 Hz during constant pressure conditions. The mechanism(s) explaining this nervous control of water absorption are tentatively discussed.     

Frequency of Hepatic Cysts in Adult Polycystic Kidney Disease

Abstract. The frequency of hepatic cysts in patients with adult polycystic kidney disease (APKD) is usually considered to average about 33%, but with great, and hitherto largely unexplained, variations between different studies. Sixty-six consecutive patients with APKD were all subjected to CT scanning of the liver and of the kidneys. In confirmation of one previous study, a clearcut correlation was found between age (=duration of disease) and the frequency of hepatic cysts. It was furthermore found that cysts in the liver, as opposed to cysts in the kidneys, continue to grow and appear de novo even after institution of renal replacement therapy.     

Differences in Referral Rates from General Practice

There are many unexplained differences in the rates at whichgeneral practitioners make referrals to other medical specialists.This study investigated 17 586 referrals from 141 general practitionersto specialists in seven specialties in Ringkjøbing countyin Denmark. As an expression of the referral rate, a referralindex was estimated for every general practitioner. The referralindex was the number of referrals to the specialist per 1000patients per year, including children, standardized for ageand sex to the average population in Ringkjøbing county.The following six variables were evaluated in relation to thereferral index: specialists in the local area, doctors per practice,consultations per general practitioner per year, patients registered,consultations per 1000 patients per year standardized for ageand sex, and supplementary procedures per consultation. Stepwisemultiple regression analysis was used. The study showed thatthe referral index rose both with a better access to specialistand with an increasing number of consultations per practitionerper year. The referral index fell with increased numbers ofpatients registered. No correlation was found between the referralindex and number of supplementary procedures per consultation,number of doctors per practice and number of consultations per1000 patients per year.     

Excessive Hypercalcaemia and Mixed Connective Tissue Disease

ABSTRACT A 23-year-old female with extreme hypercalcaemia was treated with calcitonin, mitramycin and parathyroidectomy and normocalcaemia was achieved after 4 weeks. Nevertheless, the patient later died of cutaneous necrosis, impaired circulation and multiple organ failure. Serum immunoreactive parathyroid hormone was in the normal range and parathyroid tissue normal. Mixed connective tissue disease was diagnosed on the basis of high titers of antibody to extractable nuclear antigen, moderately elevated levels of antibody to nuclear antigen and only marginal elevation of anti-double standed DNA. The role of Cl. difficile toxin in the blood and an acinic cell tumour is unclear.