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Biomedical subjects

K Rager

Publications and source records attributed to K Rager.

At least 19 recordsLinked to original sources
PubMed1990

[Sudden death caused by a heart tumor].

Primary cardiac tumors in infancy and childhood are extremely rare. In the young age group the clinical symptoms often are variable and can make diagnosis difficult. Depending on the histological character and especially the localisation of the mass the clinical appearance may lead to the first diagnosis or at least to further investigation. While myocardial tumors (rhabdomyomas and fibromas) mainly cause rhythmic disturbances, the intracavitary tumors (like myxomas) frequently disturb hemodynamics. Echo-cardiography is the main diagnostic technique, followed by angiocardiography, computertomography and nuclearmagneticresonance imaging.

Child↗
PubMed1986

Ontogeny of circadian rhythmicity for melatonin, serotonin, and N-acetylserotonin in humans.

The serum concentration of melatonin, serotonin, and N-acetylserotonin were measured by RIA procedures in 28 infants aged 1 week to 9 months. Blood specimens were obtained at 12:00 hr and 24:00 hr. A day-night difference in serum serotonin was present immediately after birth. A significant (P less than 0.001) decrease in serum serotonin concentrations at 12:00 hr and 24:00 hr was observed from the first month of age to the third to ninth month of age. A significant (P less than 0.05) difference in day-night N-acetylserotonin concentration is first seen at age 1-3 months. Serum melatonin concentrations, though detectable, did not show any day-night difference at birth. Melatonin concentrations progressively increased up to the third month of age, and a significant (P less than 0.01) day-night difference appeared thereafter. The results indicate that in humans the circadian organization for serotonin already exists at birth, and the circadian melatonin rhythm develops after birth.

Age Factors↗
PubMed1982

Effect of human chorionic gonadotropin on the plasma levels of testosterone, estradiol, sex hormone binding globuline and free testosterone in Klinefelter syndrome.

Preliminary experiments showed that a course of 3 X 5000 IU Human Chorionic Gonadotropin (HCG) every alternate day in 5 patients with Klinefelter Syndrome caused increment in the circulating levels of testosterone, estradiol, and Sex Hormone Binding Globuline (SHBG). The levels of free testosterone, however, declined in 3 subjects and recorded no change in the remaining two. Estradiol/testosterone ratio on day 0 showed high correlation (r = 0.853) with augmented SHBG. It has been postulated that higher amount of SHBG is perhaps potentiating a reduction in the bioavailability of testosterone.

Adult↗
PubMed1976

[Effects of longterm HCG administration on testicular function in hemodialysis patients (author's transl)].

Thirtheen male patients with chronic renal failure undergoing regular dialysis treatment (2 X 8-10 hours/week) were treated with gonadotropins (HCG, Primogonyl) primarily 2 X 2,000 IU/week and later 2,000 IU/week. Before HCG administration and during 4-months HCG-therapy testosterone, dihydrotestosterone, Androstandiol, LH and FSH levels were determined by RIA-methods in 7-14 days intervals. Before HCG-application plasma testosterone levels were low and did not increase in the course of regular dialysis treatment. Derivates from testosterone like dihydrotestosterone and Androstandiol were elevated in plasma, presumbably because of accumulation in renal failure. LH-levels were slightly elevated on the average. FSH-levels showed a high individual variation but also seemed to be elevated on the average. HCG stimulation by exogenous HCG administration for short time resulted in a insufficient rise of testosterone levels as compared to normals. During prolonged HCG administration plasma testosterone levels increased to normal but dropped immediatly after cessation of therapy or reduction to less than 2,000 IU HCG twice/week. Body weight, plasma proteins, haematocrite and fertility did not improve significantly. These results indicate that in chronic renal failure androgen synthesis by testicular tissue is seriously impaired and does not improve under usual dialysis treatment. Feedback regulation of testosterone levels by increase of LH levels seems not to be sufficient although pituitary response is found to be normal. This may be explained by elevated levels of testosterone derivates which exert negative feedback effects.

Adult↗
PubMed1976

Plasma testosterone in prepubertal cryptorchid boys under long-term HCG therapy.

Plasma testosterone concentrations were determined before and after 6 weeks of human chorionic gonadotropin treatment in 36 prepubertal boys with bilateral or unilateral cryptorchidism. Mean +/- SD basal and post-treatment values (ng/100 ml) in the bilateral group were: treatment successful (n = 14): 32 +/- 19 and 302 +/- 49, treatment unsuccessful (n = 12): 20 +/- 15 and 176 +/- 73. The figures for the unilateral group were: treatment successful (n = 6): 23 +/- 9 and 244 +/- 41, treatment unsuccessful (n = 5): 22 +/- 11 and 264 +/- 102. In the bilateral group significant differences in the T response emerged when successfully treated boys were compared to unsuccessfully treated ones. It is concluded that Leydig cell function may be impaired in some cases of cryptorchidism.

Child↗
PubMed1975

Effects of experimental bilateral cryptorchidism and castration on the plasma gonadotropins in male rats during sexual maturation.

The effect of bilateral cryptorchidism and castration on serum LH and FSH was assessed in rats throughout their sexual maturation. After short time (4 days) castration marked elevations of FSH and increases of LH in plasma are recorded in all developmental stages. Bilateral cryptorchidism caused after 4 days in different age groups elevations of LH regardless of the sexual maturation. FSH was elevated in these cryptorchid animals only in more mature animals.

Age Factors↗
PubMed1975

Plasma testosterone and dihydrotestosterone in male rats during sexual maturation and following orchidectomy and experimental bilateral cryptorchidism.

Plasma concentration of testosterone and dihydrotestosterone (17beta-hydroxy-5alpha-androstan-3-one) were measured at frequent intervals (daily between day 20 and 40) in intact male rats from early pre-pubertal stage to full maturity. Effect of orchidectomy and experimental bilateral cryptorchidism on these two blood-born compounds at different stages of sexual maturation was also studied. A distinct spurt in testosterone level was noted on day 26, and in 3 days a leval of 2600pg/ml was reached, which was about 90% of the highest peak value (2940 pg/ml) seen at day 70. In the same animals dihydrotestosterone spurt was noted at the same time, but the peak value (163 pg/ml) was reached later (day 33). Within 4 days after orchidectomy plasma testosterone level showed no significant change in 20-day old animals, but dropped to 15% of the intact value in 40-day old ones, while remaining at a steady level of about 23% in older animals. Plasma dihydrotestosterone was undetectable after orchidectomy at each stage of sexual maturation. With bilateral cryptorchid animals plasma testosterone was higher than seen in the intact 20-day old control, but remained similar at other stages of sexual maturation. Plasma dihydrotesterone in the same animals was significantly less (p less 0.01) than those seen in the intact controls at all stages of sexual development except in 20-day old ones, where it was essentially similar.

Aging↗
PubMed1975

The effect of HCG on testicular androgen production in adult men with chronic renal failure.

In sixteen male patients undergoing regular haemodialysis of peritoneal dialysis for chronic renal failure, the testosterone levels were studied before and after treatment with HCG. Testosterone values before (186 ng/100 ml) and after (456 ng/100 ml) HCG were significantly lower than those for normal healthy males. The mean plasma dihydrotestosterone (5alpha-DHT) value of 11.5 ng/100 ml for the treated patients was significantly lower than that of 64 ng/100 ml for the control patients. With HCG, increments in DHT were recorded in three patients, and definite increments in testosterone were observed in six patients. The percentage binding and combining affinity showed little change due to HCG stimulation. Achieving ejaculation was a serious problem for the patients in whom the lowest increases in testosterone and 5 alpha-DHT levels were observed after HCG stimulation. Low plasma testosterone values were also associated with a low mean area for Type-2 muscle fibres.

Adult↗
PubMed1975

Levels of luteinizing hormone, follicle-stimulating hormone, testosterone and dihydrotestosterone in the circulation of sexually maturing intact male rats and after orchidectomy and experimental bilateral cryptorchidism.

Plasma concentrations of LH, FSH, testosterone and dihydrotestosterone (DHT) have been measured in normal sexually maturing male rats from the age of 16-90 days. Between 16 and 25 days plasma testosterone levels were low, but rose suddenly on day 26. A similar increment occurred at the same time in plasma DHT levels, but this steroid reached its peak concentration later than testosterone. Plasma LH levels rose steadily from day 25 onwards, reaching their highest values on day 30. A marked increase in FSH levels was found on day 16, and a peak was reached on day 33 followed by a decline to a level characteristic of the adult. In addition, plasma levels of all these hormones were estimated in the male animals at various stages of development after orchidectomy and cryptorchidism. Four days after operation, the plasma levels of LH and FSH in the orchidectomized animals reached higher levels than those found in the intact animals, indicating the existence of a dynamic feedback relationship before puberty between gonadal steroids and pituitary gonadotrophic secretion. However, results from the experimental bilaterally cryptochid animals, suggested that the gonadal steriod-gonadotrophic feedback relationship could not be the only factor initiating puberty.

Age Factors↗
PubMed1975

[In vitro tests as a tool for examination of the thyroid function in childhood and newborn stage (author's transl)].

The concentration of hormone iodine, total thyroxine and the T3-test were determined in children from the newborn-period until school-age. Hormone iodine and total thyroxine increased markedly from day 1 to 6 of life and decreased after day 21. This decrease continued until preschool-age. The T3-value was highest in the newborns and showed no significant changes during the following ages. The higher blood levels of thyroid hormone in infants during the neonate period have to be taken into account when distinguishing between hypo- and hyperthyroid patients.

Age Factors↗