The Influence of Various Irradiances of Artificial Light, Twilight, and Moonlight on the Suppression of Pineal Melatonin Content in the Syrian Hamster

The purpose of the present studies using artificial light was to determine how the timing and duration of exposure influence the light-induced suppression of pineal melatonin levels in hamsters. An 8-min exposure to 0.186 microW/cm2 of cool white fluorescent light caused a continued depression of pineal melatonin even when animals were returned to darkness. In addition, the pineal gland does not appear to change its sensitivity to light throughout the night. A 20-min exposure to 0.019 microW/cm2 of cool white fluorescent light did not significantly suppress pineal melatonin during any time of the melatonin peak, whereas a 20-min exposure to 0.186 microW/cm2 was capable of always suppressing melatonin. Furthermore, increasing the duration of 0.019-microW/cm2 exposure to 30, 60, 120, or 180 min does not increase the capacity of this irradiance to depress melatonin. Similar to artifical light, natural light has a variable capacity for suppressing nocturnal levels of pineal melatonin. Twilight irradiances of 0.138 microW/cm2 or less did not suppress nocturnal melatonin whereas twilight irradiances of 3.0 microW/cm2 or greater did suppress pineal melatonin. A few animals did have lower melatonin after a 40-min exposure to full moonlight during July (0.045 microW/cm2) or January (0.240 microW/cm2). However, pineal melatonin levels remained high in the majority of animals exposed to full moonlight.     

Hirnstammblutungen infolge kapillarer Telangiektasien — ein Substrat des plötzlichen Todes aus natürlicher Ursache

Zusammenfassung Blutungen in der Hirnbrücke aus kapillären Telangiektasien stellen selten zu beobachtende Verä nderungen dar. Es werden fünf Fälle vorgestellt, bei denen diese Blutungen auch als Todesursache gewertet werden konnten. Zweimal war es, infolge der Umstände des Falles, möglich auf einen äußerst raschen Bewußtseinsverlust und/oder sofortigen Tod zu schließen. In zwei Fällen bestand zusä tzlich eine urämische Stoffwechsellage, so daß diskutiert werden muß, ob die Blutungen nicht auch als Komplikation im Zuge der renalen Grunderkrankung aufgetreten sein könnten. Für den Gerichtsmediziner erscheint es wissenswert, daß kapilläre Telangiektasien unter Umständen auch auslösendes Substrat für ein Unfallgeschehen darstellen können.     

Screening for lung cancer in a fixed population by biennial chest radiography

All screening radiographs of the chest and other medical records of 107 patients with histologically proved lung cancer in a fixed population were reviewed to assess the efficacy of biennial chest radiography in detecting lung cancer. Radiographic abnormalities caused by tumors were initially detected in 58 patients (54%); the other 49 (46%) were detected radiographically in subsequent examinations. Thirty-six of the 40 solitary tumors were less than or equal to 4.0 cm in diameter when detected. There were no symptoms in 76% of cases, possibly associated with the predominance of peripheral adenocarcinomas. Routine 36 X 43-cm radiographs, postero-anterior stereoscopic and lateral projections, and comparison with previous radiographs facilitated detection of relatively small tumors in asymptomatic patients. The corrected 5-year survival rate from the time of detection was 20%.     

Further studies of the effects of intravenous infusion or intramuscular injection of gonadotropin-releasing hormone during childhood and adolescence

To provide data on the readily releasable pools of pituitary gonadotropins and to compare routes of administration, gonadotropin-releasing hormone (Gn-RH, 100 micrograms) was administered to 135 endocrinologically normal children and adolescents by continuous intravenous 3-hour infusion or by acute intramuscular injection. The Gn-RH infusion resulted in a significant four- and sevenfold increase in serum luteinizing hormone (LH) values in prepubertal subjects and pubertal males, respectively. A 14-fold increment, biphasic in appearance, occurred in pubertal females. Gn-RH-induced serum follicle-stimulating hormone (FSH) increases were greater in females than in males. Following intramuscular injection of Gn-RH, a monophasic increment of serum LH and FSH occurred. LH rises were greater in pubertal than in prepubertal children and greater in females than in males. FSH increments were greater in females than in males, prepubertal being slightly greater than pubertal. Urinary gonadotropin excretion mirrored the changes in the serum samples. These results in the largest reported group of normal children generally confirm those of previous reports except for the greater Gn-RH-evoked releasable LH in pubertal females than in males.     

Alpha-macroglobulin-induced release of anti-Ig-coated particles from a subpopulation of rabbit B lymphocytes.

Approximately half of the rosettes formed by rabbit Ig+ lymphocytes (B cells) and anti-coated erythrocytes or glutaraldehyde-fixed bacteria are dissociated upon the addition of rabbit serum. Rabbit serum was fractionated and the rosette-dissociating activity was found in purified preparations of rabbit alpha 1- and alpha 2-macroglobulins. Studies designed to elucidate the mechanism of rosette dissociation suggested that the alpha-macroglobulins dissociated rosettes by causing the release or proteolytic cleavage of the membrane proteins complexed with the anti-Ig-coated particles. These data suggest that the alpha-macroglobulins may have a role in the interaction of B lymphocytes with particulate antigens.     

Die Bedeutung der Natriumionen für die Beeinflussung des Aktionspotentials durch herzwirksame Glykoside

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