The role of testosterone in the feedback control of male FSH and LH secretion

Summary Intramuscular administration of 250 mg testosterone oenanthate per week over a period of 21 weeks treatment rapidly and sustainedly suppressed serum LH as well as FSH levels in seven normal males, while serum testosterone rose by a factor of approximately two. These together with other data provide increasing evidence for a feedback control of FSH secretion by gonadal steroids in the male in addition to the already described but as yet undefined tubular testicular factor.     

Microembolic Renal Disease in Rats Induced with Sephadex: Hypertension, Lesions and Serum Urea Nitrogen

Sephadex particles (20-80 μ in size) were injected into the abdominal aorta of 134 male Sprague-Dawley rats near the renal arteries. In 31 rats, the right kidney was then removed. The Sephadex particles lodged in glomerular capillaries, afferent glomerular arterioles and interlobular arteries, creating renal infarcts, some of which were grossly visible. Shortly after injection, arterial blood pressure rose significantly in most animals. The hypertension in uninephrectomized rats was not demonstrably different from that in rats with two Kidneys. Severity and duration of hypertension (up to 8 months) were positively correlated with the number of Sephadex particles in renal vessels, and there was also a positive correlation between the degree of hypertension and serum urea nitrogen levels, and between degree of hypertension and degree of cardiac hypertrophy. The vascular permeability in acutely hypertensive rats was abnormal, as judged from penetration of iron-dextran into vessel walls. This experimental model resembles atheromatous microembolic renovascular disease, which may play a significant role in the pathogenesis of unexplained hypertension in patients with advanced aortic atherosclerosis.     

Ca2+–calmodulin-dependent protein kinase expression and signalling in skeletal muscle during exercise

Ca²⁺ signalling is proposed to play an important role in skeletal muscle function during exercise. Here, we examined the expression of multifunctional Ca²⁺–calmodulin-dependent protein kinases (CaMK) in human skeletal muscle and show that CaMKII and CaMKK, but not CaMKI or CaMKIV, are expressed. Furthermore, the effect of exercise duration and intensity on skeletal muscle CaMKII activity and phosphorylation of downstream targets was examined. Eight healthy men exercised at ∼67% of peak pulmonary O₂ uptake     with muscle samples taken at rest and after 1, 10, 30, 60 and 90 min of exercise. Ten other men exercised for three consecutive 10 min bouts at 35%, 60% and 85%     with muscle samples taken at rest, at the end of each interval and 30 min post-exercise. There was a rapid and transient increase in autonomous CaMKII activity and CaMKII phosphorylation at Thr²⁸⁷ in skeletal muscle during exercise. Furthermore, the phosphorylation of phospholamban (PLN) at Thr¹⁷, which was identified as a CaMKII substrate in skeletal muscle, was rapidly (< 1 min) increased by exercise, and remained phosphorylated 5-fold above basal level during 90 min of exercise. The phosphorylation of serum response factor at Ser¹⁰³, a putative CaMKII substrate, was higher after 30 min of exercise. PLN phosphorylation at Thr¹⁷ was higher with increasing exercise intensities. These data indicate that CaMKII is the major multifunctional CaMK in skeletal muscle and its activation occurs rapidly and is sustained during continuous exercise, with the activation being greater during intense exercise.     

Significance of laboratory diagnostic study parameters of the hepatobiliary system in the evaluation of cardiovascular diseases--results of cross sectional and longitudinal studies in patients with suspicious cardiovascular findings in an epidemiologic follow-up study

With the help of an approx. 280 000 inhabitants check of x-ray-morphological suspects of a heart disease the laboratory parameters thymol turbidity test, zinc-sulphate turbidity test, total protein, serum protein electrophoresis and the enzymes "ASAT" and "ALAT" in longitudinal section and cross-section were examined in an intervention study during 5 years. All these parameters show standard values on the average, but compared to a healthy reference they showed significant differences, which relations to heart and vessel diseases could be deduced from. This referred especially to age-inverse behaviour of the transaminases only concerning male test persons. The examination of the longitudinal section confirmed exactly the results of the cross-section analysis. On the one hand it underlines the results got from the cross-section and in the second place it contributes to the efficient diagnostics by learning undone a repetition of these laboratory examinations during the period of 5 years with such a defined population. The relations of the particularities mentioned obviously refer to subclinical fields. Effects of therapy do not reflect in the laboratory findings.     

Radiologic and manometric correlation in "nutcracker esophagus"

"Nutcracker esophagus" is a newly described esophageal motor disorder seen in some patients with chest pain and/or dysphagia and characterized manometrically by normal primary peristalsis with distal contractions of high amplitude. The radiographic and manometric examinations in 20 patients with nutcracker esophagus were correlated. Normal primary peristalsis was observed radiographically in 16 patients, and a nonspecific motor disorder was diagnosed in the remaining four patients. Mild-to-severe nonspecific tertiary activity was seen in about half of the patients, esophageal wall thickness was normal. It is concluded that nutcracker esophagus is primarily a manometric diagnosis made in the appropriate clinical setting, and that the radiographic findings are normal or nonspecific.     

Tackling the scaling-up problem of digital health applications

Journal of Public Health - The purpose of this editorial is to provide guidance for the readers concerning the broad realm of approaches towards successful implementation of digital health...