The effect of heroin addiction on pituitary-testicular function

The effect of heroin addiction on pituitary-testicular function was studied in 54 active and 19 abstinent addicts and their results were compared with those of 43 age-matched controls. Abnormal sexual function was frequently found in heroin addicts and this persisted after drug withdrawal. The mean total (mean +/- SE, 18.1 +/- 1.0 nmol/1) and free (0.17 +/- 0.03 nmol/1) testosterone (T) levels in heroin addicts were significantly lower than those in healthy controls (total T 22.8 +/- 1.1 nmol/1), P less than 0.005; free T 0.30 +/- 0.03 nmol/1, P less than 0.005). The mean sex hormone binding globulin binding capacity was higher in heroin addicts (60.1 +/- 5.2 mM) than in healthy controls (35.5 +/- 2.1 mM). These hormonal changes returned promptly to normal after withdrawal. The basal LH and FSH and the responses to LHRH were comparable in the three groups studied. The finding of significantly lower total and free T together with higher SHBG indicates an abnormal testicular function in heroin addiction. Normal basal and LHRH-stimulated LH and FSH levels suggest that chronic heroin abuse depressed testicular function via the hypothalamus or higher centres.

An automated tumor resection device for neurological surgery

A pneumatically activated cutting probe has been designed for the neurosurgical removal of nervous system tumors or diseased tissue. The hand-held probe is formed of concentric slender tubes, one reciprocating inside the other. A scalpel-sharp edge on the tip of the inner tube moves in a shear motion past a stationary port on one side near the distal end of the outer tube. The reciprocating motion of the inner tube is provided by a pneumatic power source housed in a separate control console.

Effect of acute myocardial infarction on pituitary-testicular function

The effect of acute myocardial infarction on the secretions of LH, FSH and testosterone was studied in thirteen male patients. Plasma testosterone fell transiently on the fourth day after acute myocardial infarction. This was accompanied by a rise in LH on the same day which persisted for a week after infarction. Serum FSH showed no significant change. The data suggest that following the medical stress of myocardial infarction, testosterone concentration was suppressed resulting in a compensatory rise in LH.

Effect of surgical stress on pituitary-testicular function

The effect of surgical stress on the secretions of LH, FSH, testosterone (T) and oestradiol (E2) were studied in twelve male patients. During surgery LH rose significantly; post-operatively, LH fell but remained persistently elevated a week after operation. However, T and E2 fell progressively to a nadir on the second and fifth post-operative day respectively and remained suppressed. Serum FSH showed no significant change. Despite a post-operative decrease in sex hormone binding globulin (SHBG) binding capacity, non-SHBG bound T showed a decrease parallel to T. Multiple sampling studies showed that the secretions of LH were increased and that of T were decreased post-operatively. Following surgery, LH responses to LHRH were magnified, FSH and T responses showed no significant change when compared with the pre-operative responses. These data suggest that secretions of LH were increased during surgery. Following surgical stress, T and E2 concentrations were suppressed resulting in a compensatory elevation of LH concentrations.

Pituitary-thyroid responses to surgical stress

The effect of surgery on pituitary-thyroid function was studied in 12 euthyroid patients. There was a sharp early increase in total thyroxine level, causing displacement of triiodothyronine from thyroid hormone binding proteins resulting in the elevation of the biologically more potent free triiodothyronine fraction. The serum triiodothyronine concentration fell rapidly during and after the operation, with a concomitant rise in reverse triiodothyronine level. Increased prolactin levels were found during and after surgery. With no post-operative complication, recovery of normal pituitary-thyroid function occurred after 4 to 7 days of convalescence.

Hypertension due to 17alpha-hydroxylase deficiency

A female patient with hypertension, hypogonadism and hypokalaemia due to 17alpha-hydroxylase deficiency is described, in whom the diagnosis was initially based on the finding of low urinary 17-ketosteroids and 17-hydroxycorticosteroids, in the presence of high plasma fluorometric 11-hydroxycorticoids. Later studies confirmed the diagnosis by demonstrating low circulating levels of 17alpha-hydroxyprogesterone and the steroids derived from this precursor: 11-deoxycortisol, cortisol, oestradiol and testosterone. Plasma progesterone, corticosterone and deoxycorticosterone (DOC) were greatly increased, but plasma and urine aldosterone were very low. The initial subnormal cortisol and 11-deoxycortisol levels responded to tetracosactrin administration, suggesting that the adrenal was not maximally stimulated by endogenous ACTH and indicating that the 17alpha-hydroxylase deficiency was incomplete. Plasma and urinary aldosterone levels were still suppressed after 12 months treatment with prednisone despite normalization of the previously suppressed renin levels. The findings indicate that this uncommon cause of medically-controllable juvenile hypertension can be identified without specific steroid assays.

Molecular evolution of snake venom toxins

Phylogenetic trees were constructed for 62 venom toxins of snakes of Proteroglyphae suborder using matrix method. The resulting tree from Minimum Spanning Tree-Cluster Analysis technique had the lowest "percent deviation" (8.55). The taxonomic relationship of these toxins agrees very well with zoological opinions. However, the appearance of the tree did not directly provide a plausible evolutionary model for the toxins. A model was derived from nodal ancestral sequence calculations, comparisons between intra- and intergenerical rates of amino acid change, and generally held ideas about protein evolution. According to the model, short neurotoxin is the ancient form of snake venom toxins. The courses of evolution leading to the present intraspecific homologous toxins are explained by gene duplication and allelomorphism.

Conformational prediction for snake venom toxins and laser Raman scattering of a cardiotoxin from Taiwan cobra (Naja naja atra) venom

Secondary structure regions in snake venom toxins were predicted using the prediction method of Chou and Fasman (Chou, P. Y., and Fasman, G. D. (1974), biochemistry 13,222) and an averaging scheme assuming structural homology in each type of toxins. The results indicate that, in general, snake toxins contain only some beta-sheet regions and beta bends. The content of secondary structures thus predicted does vary to some extent. The predicted results correlate well with conclusions from physicochemical studies. Interestingly, beta-bend regions predicted for the two types of neurotoxins, short-neurotoxin-type and long-neurotoxin-type, are primarily located in the middle of disulfide loops in spite of large differences in primary sequences. Comparisons between predicted results and the crystal structure of erabutoxin b determined at 2.75 A resolution suggest that the two types of neurotoxin are both sequencely and conformationally related while cardiotoxins could have an entirely different molecular topology. The Raman spectrum of a Taiwan cobra cardiotoxin indicates that the content of beta-pleated-sheet structure could be greater than that in neurotoxins.

Needle biopsy of the thyroid

As with any specialized diagnostic technique, the degree of success and safety of needle biopsy of the thyroid are largely based on experience. While an adequate core of tissue for examination is imperative, the interpretation by the pathologist is equally important. A close liaison of the latter with his clinical colleagues is necessary for optimal pathologic evaluation. A review of this experience during a 20 year period shows that needle biopsy is a reliable diagnostic procedure in more than 90 per cent of the patients. It is unlikely to disseminate the disease or compromise the prognosis, and it is a safe office procedure.

Changes in the pituitary-testicular system with age

In order to provide a comprehensive account of pituitary-testicular function in man, 466 subjects, ranging in age from 2 to 101 years, were studied to examine blood levels of the pituitary gonadotrophins (LH and FSH), the sex steroids testosterone and oestradiol, the binding capacity of the sex hormone binding globulin (SHBG), the free testosterone and oestradiol fractions, and the transfer constant for the peripheral conversion of testosterone to oestradiol. The results were compared with clinical indices of testicular size, sexual function and secondary sex hair distribution. Serum LH and FSH were low before puberty, increased in pubertal adolescents to levels somewhat above those of adults and subsequently increased progressively over the age of 40 years. Testosterone levels fell slowly after the age of 40, while there was a slight rise in plasma oestradiol with increasing age. FSH and testosterone showed small seasonal variations in young adult men, the lowest values being seen in winter. SHBG binding capacity was high in two prepubertal boys, fell in adult men, but increased in old age. Free testosterone and oestradiol levels fell in old age. The metabolic clearance rates (MCR) of testosterone and oestradiol also fell in old age, while the conversion of testosterone to oestradiol was increased. Many correlations were observed between various hormonal and clincial measurements. The evidence is consistent with a primary decrease in testicular function over the age of 40 years.

The anatomic basis of parathyroid surgery

A study of 645 normal adult parathyroid glands in 160 cadavers revealed that there is a definite pattern of anatomic distribution on the basis of the embryologic development of the parathyroid, thyroid, and thymic glands. The sites of predilection of the upper gland (Parathyroid IV) are, in order of frequency, the cricothyroid junction; the dorsum of the upper pole of the thyroid; and the retropharyngeal space. Those of the lower gland (Parathyroid III) are at the lower pole of the thyroid and the thymic tongue; rarely in the upper, the lateral neck, or the mediastinum. An understanding of the developmental relationship of the parathyroid glands to the thyroid and the thymus is fundamental in the delineation of the embryologic origin of the parathyroid glands. The parathyroid gland, located within the surgical capsule of the thyroid (subcapsular), when diseased, remains in place locally. A gland outside of the capsule (extracapsular) is often displaced into the posterior or anterior mediastinum. A collective assessment of the size, weight, color, shape, and consistency of the parathyroid gland is mandatory in the determination of its normalcy. Frozen section examination for stromal and intracellular fatty content is an added assurance of normalcy. That parathyroid glands sink in saline solution, and fat globules float, may aid in differentiating the two types of tissue. Supernumerary, fused, and intrathyroidal parathyroids, albeit rare, are of surgical importance.

A study of the endocrine manifestations of hepatic cirrhosis

The clinical features and hormonal abnormalities were surveyed in 117 men with cirrhosis of the liver. Compared with healthy men of similar ages, the patients had significantly lower metabolic clearance rates, plasma production rates and total and free levels of testosterone, reduced testosterone responses to human chorionic gonadotrophin stimulation, higher oestradiol, luteinizing hormone and follicle stimulating hormone levels and higher binding capacities of sex steroid binding globulin. The peripheral conversion of testosterone to oestradiol was also found to be significantly increased. However, the metabolic clearance and plasma production rates of oestradiol were not significantly different from those of healthy men. Patients who were severely ill with liver failure and one with haemochromatosis had low levels of luteinizing hormone and follicle stimulating hormone and sub-normal responses to clomiphene and luteinizing hormone-releasing hormone. Higher plasma oestradiol levels were found in patients with gynaecomastia and spider naevi than in those without these signs. However, the clinical features of androgen deficiency--that is, testicular atrophy, impotence and loss of secondary sex hair--were only poorly related to the low testosterone levels, and production rates and longtitudinal studies indicated that the hormonal levels, endocrine features and severity of the liver disease could change independently. It is concluded that the clearance of oestradiol from plasma is not limited by liver disease in all patients, and that reduced degradation of oestrogens is not the initial event in the sequence leading to the hormonal abnormalities of cirrhosis. While gonadotrophin deficiency occurs with liver failure and in some patients with haemochromatosis, the more usual findings are of elevated gonadotrophin levels and a poor Leydig cell response to chorionic gonadotrophin. These suggest that the hypogonadism is primary in most patients with cirrhosis. The causes of the high oestradiol levels were not discovered. Increased peripheral conversion of precursors to oestradiol or increased testicular secretion of oestradiol are possibilities. The high binding capacities of sex steroid binding globulin were not significantly correlated with either the low testosterone or high oestradiol level and the cause of this abnormality remains uncertain. The low metabolic clearance rates of testosterone appeared to result from the increased plasma protein binding of testosterone. The discrepancies in the expected relationships between the hormone and clinical changes suggest that factors other than those studied are also involved in the genesis of the endocrine features of hepatic cirrhosis.

Hormonal studies in Klinefelter's syndrome

Some aspects of the hormonal abnormalities of Klinefelter's syndrome have been studied in nineteen patients. As a group the plasma production rate, the total and free levels of testosterone, and the metabolic clearance rates of testosterone and oestradiol were low. Plasma oestradiol, LH and FSH levels were elevated and there was increased peripheral conversion of testosterone to oestradiol. The production rates of oestradiol and the binding capacities of the sex steroid binding globulin were normal. There were fluctuations in the blood levels of LH, FSH, testosterone and oestradiol, but these appeared to be less marked than in healthy men. Both LH and FSH levels were suppressed by acute or prolonged testosterone administration and there was no evidence for a differential effect on LH. It is suggested that the threshold for suppression of LH and FSH is increased in hypergonadotrophic states. Although no statistically significant relationships were found between the hormonal and clinical abnormalities of the syndrome it is probable that the hyperoestrogenism and androgen deficiency are linked to the development of the signs of feminization and hypogonadism.

The use of the inferior cornu of the thyroid cartilage in identifying the recurrent laryngeal nerve

The inferior thyroid artery, traditionally used as a guide in identifying the recurrent laryngeal nerve, is not wholly reliable because of two factors which affect the constancy of the relation between nerve and artery. One is the variability of the anatomic pattern of tbe inferior thyroid artery, and the other is the occasional incidence of a nonrecurrent inferior laryngeal nerve. In a study of 500 recurrent laryngeal nerves, the inferior cornu of the thyroid cartilage was more reliable than the inferior thyroid artery in identifying the recurrent laryngeal nerve. The anatomic relation between the recurrent laryngeal nerve and the inferior cornu of the thyroid cartilage was constant in all patients, except those in whom there was displacement of the nerve resulting from lesions of the thyroid or the parathyroid glands. Operations upon the neck require understanding of the anatomic characteristics of the recurrent laryngeal nerve and of possible involvement of the nerve with the pathologic process involvement of the nerve with the pathologic process as well as fastidious operative technique.

Variations in serum FSH, LH and testosterone levels in male rats from birth to sexual maturity

Serum LH, FSH and testosterone concentrations were measured by radioimmunoassays in male Sprague-Dawley rats from birth to 80 days of age. The levels of FSH were significantly elevated during the first 5 days of postnatal life. An abrupt decline in FSH concentrations occurred during this period, from levels of 800 ng/ml on day 1 to levels of 300 ng/ml on Day 6. Subsequently, FSH levels fluctuated widely until about Days 30 to 45, when a secondary peak of FSH was observed. Thereafter, a decline in FSH levels to those found in adult rats occurred. This decline in FSH levels appears to coincide with the first release of mature spermatozoa from the germinal epithelium in the testis. During the first 30 days of postnatal life, LH and testosterone values appeared to be inversely related to each other and an LH peak and a nadir of testosterone levels was observed between Days 6 and 14 at time corresponding to regression of the fetal generation of interstitial cells. A parallel rise in LH and testosterone levels occurred from Days 30 to sexual maturity and corresponded to the development of the adult generation of intestitial cells.