bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved sensitivity to adrenocorticotrophin after purification and pre-incubation of isolated rat adrenal cells
Authors: Goverde H. J. M. , Pesman G. J. , Benraad Th. J. 
Published: December 2008

Abstract.
A highly sensitive bioassay for adrenocorticotrophin (ACTH) has been developed, in which isolated adrenal cells, purified previously by passage through a 5% BSA layer were pre-incubated for 1 h. The detection limit for hACTH1-39 in this system is 0.19 ± 0.10 (sd) fmol/ml. As a result of the purification step the ED50 for hACTH1-39 decreased from 14.1 ± 4.8 to 6.9 ± 1.2 fmol/ml. Pre-incubation of the purified cells decreased this value significantly to 4.0 ± 1.5 fmol/ml. For ACTH1-24 the increase of sensitivity after purification was even higher, the ED50 changing from 7.1 ± 4.2 to 1.6 ± 0.2 fmol/ml. After pre-incubation of the purified cells this value amounted to 0.8 ± 0.3 fmol/ml. After purification and pre-incubation of the adrenal cells the changes observed for the ED50's of hACTH1-32 and of a highly purified human hypophyseal extract paralleled exactly the change observed for hACTH1-39.
The improved sensitivity of the purified cell suspension might in fact represent a decrease in ACTH degradation. Both purification and pre-incubation could lead to removal or inactivation of enzymes which attach the polypeptide hormone. This hypothesis is supported by experiments in which the cell suspension has been contaminated with an adrenal homogenated prior to the purification and pre-incubation steps.
The present results indicate that pre-incubation of purified isolated adrenal cells has increased the sensitivity and that the amino acid sequence 33–39 is not involved in protecting the molecule from proteolytic attack.
Effects of immunizing rabbits against oestradiol-6-oxime-BSA on ovarian follicular development
Authors: Wielgosz G. J. , Low M. J. , YoungLai E. V. 
Published: December 2008

Abstract.
Female rabbits were actively immunized either against bovine serum albumin (BSA) or oestradiol-6-oxime BSA. When the antibody titres were elevated they were sacrificed and various parameters measured. Uterine weights were significantly lower, and a large number of haemorrhagic and some cystic follicles were present in the ovaries of the oestradiol immunized group. Increased serum gonadotrophins, testosterone, oestradiol, and progesterone levels as well as greater serum binding of oestradiol were also noted. Examination of the response of isolated follicles to gonadotrophin treatment in vitro indicated that oestradiol immunization decreased the ability of isolated follicles to form androgen and oestrogen following gonadotrophin treatment; however, progesterone levels were high regardless of the presence or absence of gonadotrophins. These data suggest that oestradiol plays an important role in follicular development.
The effect of bromocriptine during early pregnancy in the rat: inhibition of implantation
Authors: Müller U. , Bauknecht Th. , Siebers J. W. 
Published: December 2008

Abstract.
The increase in the number of the ovarian LH/hCG-receptors and of serum progesterone concentration during pregnancy in the rat is highly dependent on the presence of prolactin during the luteinization process. Blocking of the hypophyseal prolactin secretion by twice daily injections of 2 μg/g body weight bromocriptine into rats from the first day of pregnancy onwards prevents the increase in ovarian hCG-binding and progesterone production. Similar results are obtained by application of bromocriptine during the first three days only or either at day 1, 3 or 5 after mating. In all bromocriptine treated rats implantation of blastocysts does not occur. The failure to implant is not due to a teratogenic effect of bromocriptine onto preimplantation embryos, but is probably the consequence of changes of the uterine mucosa caused by the lack of progesterone production in the luteal cells.
Post-pubertal female psychosexual orientation in incomplete male pseudohermaphroditism type 2 (5α-reductase deficiency)
Authors: Cantú J. M. , Corona-Rivera E. , Díaz M. , Medina C. , Esquinca E. , Cortés-Gallegos V. , Vaca G. , Hernández A. 
Published: December 2008

Abstract.
An 18 year-old 46,XY female-reared patient with incomplete male pseudohermaphroditism type 2 (5α-reductase deficiency) was studied. She had a male habitus, Wolffian ducts derivatives, normal testes and small phallus; there were no Mullerian duct derivatives nor gynaecomastia. Clinical and genetic data were typical of the diagnosis which was corroborated by endocrinological studies. Normal LH, FSH, testosterone (T) and oestradiol and decreased dihydrotestosterone (DHT) plasma levels before and after hCG administration were found; the T:DHT ratio was highly increased. The histopathological studies of a testis biopsy showed a normal adult male pattern, and the meiotic chromosomes were interpreted as normal. After assessment of her psychosexual orientation, successful surgical and medical therapy to maintain and improve her femaleness was effectuated. The post-pubertal gender role switch commonly observed in these female-reared patients is discussed.
Renal handling of 3,3',5'-triiodothyronine (reverse T3) compared to thyroxine and 3,5,3'-triiodothyronine in different thyroid function states in man
Authors: Rogowski Preben , Faber Jens , Siersbæk-Nielsen Kaj 
Published: December 2008

Abstract.
The aim of the present work was to investigate the renal clearance of 3,3',5'-triiodothyronine (reverse T3, rT3) compared to thyroxine (T4) and 3,5,3'-triiodothyronine (T3) clearance. The urinary excretion of T4. T3 and rT3 was estimated by radioimmunoassay, serum unbound hormones (AFT4, AFT3, AFrT3) were measured using ultrafiltration technique. In 27 euthyroid controls the 24 h urinary T4 excretion was in median 1.7 nmol. T3 excretion 0.8 nmol and rT3 excretion 0.08 nmol. Serum AFT4 was in median 59 pmol/l, AFT3 7.9 pmol/l and AFrT3 2.2 pmol/l. Creatinine clearance was in median 93 ml/min. Median renal clearance of T4, T3 and rT3 were 26, 70 and 25 ml/min, and apparent tubular re-absorption was in average 77, 27 and 77%, respectively. In 18 hyperthyroid patients urinary hormone excretion was highly increased and was found parallel to the increase in serum concentrations of free hormones. Clearance and per cent tubular re-absorption of T4 and rT3 were equal to and not different from control values, but T3 clearance seemed to be increased to values higher than glomerular filtration rate (GFR). In 8 patients with hypothyroidism low urinary hormone excretion was found. Clearance of T4 and rT3 did not differ from control values, but T3 clearance was reduced.
Our data show that T4, T3 and rT3 are excreted by glomerular filtration of free hormones and suggest that tubular transport mechanisms are involved. The hypothesis is put forward that the renal handling of the thyronines is influenced by the number of the outer phenolic ring iodine atoms.
Diabetes in pregnancy: effects on the foetal and newborn rat with particular regard to body weight, serum insulin concentration and pancreatic contents of insulin, glucagon and somatostatin
Authors: Eriksson Ulf , Andersson Arne , Efendić Suad , Elde Robert , Hellerström Claes 
Published: December 2008

Abstract.
Streptozotocin (SZ) treated virgin female rats, classified as either manifest diabetic (MD) or subdiabetic (SD) according to intraperitoneal glucose tolerance tests, were mated. Normal untreated rats (N) were also mated and used as controls. On gestational day 20 the MD foetuses showed decreased litter sizes, elevated blood glucose values and glucose-to-insulin ratios, decreased body and pancreatic weights and markedly diminished pancreatic insulin contents. The MD pregnancy was prolonged by two days and about 50 per cent of the offspring died perinatally. Both the wet and dry carcass weights of the non-viable MD offspring were increased, but when correction was made for the prolonged gestational period both the viable and non-viable newborns were lighter than those of the other groups. In the viable newborns of MD mothers the blood glucose concentration was elevated and the pancreatic contents of insulin and somatostatin decreased while that of glucagon remained unchanged. The 20-day-old SD foetuses showed increased pancreatic insulin and somatostatin contents but were identical to N foetuses in all other respects. Similarly, the newborns of SD mothers remained indistinguishable from those of the N mothers.
It is concluded that, in the rat, severe SZ-diabetes induced before pregnancy causes foetal growth retardation and decreased pancreatic insulin stores. The observations suggest that excessive hyperglycaemia in the foetus hampers the normal development of the pancreatic B-cell. The absence of macrosomia and hyperinsulinism in both the MD and SD newborns suggests a difference between human and rat foetal development in diabetic pregnancy.
Relationship between insulin secretion, insulin content and dry weight of single rat pancreatic islets
Authors: Wolters G. H. J. , Konijnendijk W. 
Published: December 2008

Abstract.
Single islets were incubated at glucose 5 mm for 60 min and subsequently at glucose 15 mm for 30 min. The insulin content of the incubated islets was proportional to the dry weight of the islets. The insulin secretion (Y) demonstrated a curvilinear relationship with the dry weight (X) of the islets, which could be described by the function Y = aX⅔ (a being a constant). On basis of this function it can be calculated that the insulin secretion of a particular islet is proportional to its outer surface. The consequence of this is that small sized islets secrete relatively much more insulin than large islets. Islets isolated with either purified or crude collagenase gave the same results except that a higher basal insulin secretion was observed with crude collagenase.
Urinary tetrahydrocortisone and tetrahydrocortisol glucosiduronates in normal newborns, children and adults
Authors: Aranoff Gaya , Rosier Ariel 
Published: December 2008

Abstract.
Utilizing a simple, highly specific radioimmunoassay (RIA), we measured the excretion of the glucosiduronate conjugates of tetrahydrocortisone (THE-gluc) and tetrahydrocortisol (THF-gluc) in adults (n = 16), children (n = 58) and newborns (n = 5), in order to establish a normal range of values for age and surface area. Both tetrahydrometabolites showed a linear inrease with age but became constant for all individuals except newborns when results were calculated per square meter. Newborns excreted disproportionately low levels of these metabolites for their size. In children of similar ages, when 24h urine collections (n = 13) were compared to spot AM specimens (AM-Sp) (n = 45) in which the daily volume was estimated by creatinine excretion, THE-gluc/m2 levels were significantly higher in AM-Sp urines but THF-gluc/m2 levels were similar. Levels of both metabolites were markedly elevated in two patients with hyperadrenal states and low in three patients with hypoadrenal states compared to normal values per m2. These results indicate that the RIA for THE-gluc and THF-gluc can be a useful indirect test of cortisol secretion in children as well as in adults. Although 24h urine collections are more accurate, creatinine corrected AM-Sp urines may be clinically useful when values of these metabolites per m2 are compared to appropriate controls.
Direct effects of medroxyprogesterone acetate (MPA) and megestrol acetate (MGA) on rat testicular steroidogenesis
Authors: Barbieri Robert L. , Ryan Kenneth J. 
Published: December 2008

Abstract.
The effects of MPA and MGA on rat testicular steroidogenesis were examined by studying: 1) serum testosterone in hCG primed animals treated with MPA or MGA, 2) testosterone synthesis in rat Leydig cells cultured with MPA or MGA, 3) MPA and MGA binding to rat testis microsomal cytochrome P-450 and 4) MPA and MGA inhibition of enzymes of rat testicular steroidogenesis. In immature rats receiving 1.0 IU of hCG per day 20 mg/kg of MPA or MGA reduced serum testosterone by 57 and 56%, respectively. In mature male rats receiving 50.0 IU of hCG per day 20 mg/kg of MPA or MGA reduced serum testosterone by 40 and 29%, respectively. In rat interstitial cells cultured with 10 ng of rat LH, 1 μm MPA or MGA inhibited testosterone production by 32 and 23%, respectively. Addition of MPA or MGA to microsomal preparations resulted in a type I cytochrome P-450 difference spectrum. MPA and MGA inhibited rat testicular 17α-hydroxylase, 17,20-lyase, and the 3β- and 17β-hydroxysteroid dehydrogenases. These findings suggest that MPA and MGA inhibit rat testicular steroidogenesis in vivo and in vitro.
Effect of cyproterone acetate on platelet aggregability, fibrinolytic activity and fibrinolytic capacity in normal men
Authors: Føgh Marie , Knudsen Jens Bjerrre , Gormsen Johannes 
Published: December 2008

Abstract.
Nine healthy men were treated with a daily dose of 5 or 10 mg of the anti-androgen cyproterone acetate. Patelet aggregability was increased in 6 of 9 men; fibrinolytic activity decreased in 7 of 7 and the fibrinolytic capacity decreased in 5 of 7 volunteers. We conclude that platelet aggregability, fibrinolytic activity and capacity may be modified by anti-androgen treatment and therefore attention should be paid to the coagulation parameters when cyproterone acetate is used.
Urinary 3',5'-cyclic adenosine monophosphate in relation to serum and urinary calcium in acromegaly and primary hyperparathyroidism
Authors: Halse Johan 
Published: December 2008

Abstract.
A comparison of the interrelations between serum and urinary calcium values and the urinary excretion of cAMP in acromegaly (No. of subjects: 26), patients with primary hyperparathyroidism (n = 18) and control subjects (n = 42) is presented.
The cAMP excretion was greatest in primary hyperparathyroidism, but acromegalics also exhibited higher values for this parameter than controls. A positive correlation was found between serum calcium values and cAMP in primary hyperparathyroidism, while acromegalics showed no correlation between these parameters. In controls there was a negative correlation between serum calcium and cAMP. Serum calcium levels corrected for variations in total protein concentrations were elevated both in acromegaly and primary hyperparathyroidism, mostly in the latter.
Acromegalics and patients with primary hyperparathyroidism exhibited an increase in 24 h calcium excretion. While there was a negative relationship between urinary calcium excretion and cAMP in acromegaly, a positive correlation between these parameters was found in primary hyperparathyroidism. Controls showed a negative correlation between urinary calcium values and cAMP.
It is concluded that the role of the parathyroids in the regulation of calcium metabolism in acromegaly is different from that of both normal controls and primary hyperparathyroidism. It is postulated that an active form of Vitamin D plays a major role in the regulation of calcium metabolism in acromegaly.
Growth hormone dependent human serum stimulation of thymidine and sulphate incorporation into embryonic chicken cartilage
Authors: Jennings John , Buchanan Fred , Levitsky Lynne , Garland John T. 
Published: December 2008

Abstract.
The embryonic chicken cartilage somatomedin bioassay was modified so that human serum stimulation of simultaneous [3H]methylthymidine and H2[35S]04 incorporation could be assessed. The assay consisted of a 6 h pre-incubation of 10 day pelvic rudiments in enriched buffer, followed by a 24 h incubation with buffer and low (0.5, 2 and 5% v/v) serum concentrations. Both labels were present for the final 6 h. Other modifications were shortening of washing, elimination of drying and weighing, and simplification of digestion.
Normal human serum produced a linear log dose-response with these serum concentrations. Potency ratios in patients with GH deficiency were less than those of normal adults for both thymidine 0.39 ± 0.05 (mean ± sem, n = 16, range 0.22-0.71) vs. 0.90 ± 0.05 (n = 19, 0.62—1.36, P< 0.001) and for sulphate 0.40 ± 0.04 (0.15—0.65) vs. 94 ± 0.05 (0.61—1.29, P< 0.001). Potency ratios for both labels rose following administration of a single dose (0.2 IU/kg im) of hGH to 4 GH deficient children.
The reliability of prediction of GH deficiency, reproducibility, and precision were similar to other Sm bioassays. The major advantages of these modifications were the ability to examine 2 cartilage metabolic processes simultaneously and the small amount of serum (350 μl) necessary for patient assays.
Hypothalamic-pituitary-testicular function in rats after supraphysiological doses of a highly active LRH analogue (buserelin)
Authors: Sandow J. , Rechenberg W. v. , Jerzabek G. , Engelbart K. , Kuhl H. , Fraser H. 
Published: December 2008

Abstract.
Male pre-pubertal rats (60 g) were treated with the LRH analogue, [D-Ser(But)6]LRH(1—9)-nonapeptide-ethylamide (buserelin, Hoe 766), during 4 weeks by daily sc injections of 5, 50 or 500 ng peptide (group I, II and III). At the end of treatment, hypothalamic LRH content and arylamidase activity (LRH degrading enzyme) were not changed. Pituitary arylamidase activity was reduced, but the pituitary LRH receptors (tested by analogue binding in vitro) were not diminished. Pituitary accumulation of [125I]buserelin 60 min after iv injection was not modified and organ distribution in liver and kidney was unchanged. Pituitary responsiveness to the analogue was reduced at the highest dose, but there was significant LH-release at all three dose levels. Testosterone production in vitro (stimulated by hCG) was unaltered in group I and dramatically reduced in group II and III. Testicular testosterone content and hCG binding by testes homogenates were dose-dependently reduced. Histology of the testes after 4 weeks treatment showed minimal impairment of spermatogenesis at the highest dose, whereas the epididymis was almost devoid of sperm. The results indicate, that low dose treatment with a highly active LRH analogue, buserelin, does not interfere with pituitary responsiveness (LRH receptors and LH-release) and testicular function (testosterone production, testosterone content, LH-receptor level). At higher doses, pituitary and testicular responsiveness are dose-dependently inhibited. At the pituitary level, LRH receptors were not reduced. The antifertility effect of supraphysiological doses at the testicular level is explained by an LH-dependent loss of LH-receptors.
24-h profile of serum rT3 and serum 3,3'-T2 in normal man
Authors: Weeke Jørgen , Laurberg Peter 
Published: December 2008

Abstract.
In a previous study we found a night surge in serum free T3 varying in parallel with that of serum TSH. In order to evaluate whether diurnal alterations in peripheral iodothyronine monodeiodination may be involved we have measured two products of peripheral deiodination, 3,3',5'-T3 (rT3) and 3,3'-T2 in serum samples obtained at short intervals during a 24-h period in 5 normal male subjects. Serum rT3 was rather stable during the period albeit with a trend towards lower levels during the night when the subjects were in bed. In order to obtain a measure of free rT3 a free rT3 index was calculated using the combined variations in per cent free T4 and free T3. Night and day levels of this rT3 index were found identical, suggesting a lack of diurnal variation in serum free rT3. Likewise serum 3,3'-T2 levels were identical during the day and night periods.
The results suggest that variations in peripheral iodothyronine deiodinations are not involved in the night increase in serum free T3.
Immunochemical demonstration of human chorionic gonadotrophin (hCG) in tissue of breast carcinoma
Authors: Castro A. , Buschbaum P. , Nadji M. , Voigt W. , Tabei S. , Morales A. 
Published: December 2008

Abstract.
Immunoreactive human chorionic gonadotrophin (hCG) was found in 9 of 65 surgically removed malignant breast tumours. The concentrations found ranged from 5 to greater than 500 mIU hCG/g tumour. Of the nine, seven extracts were assayed for total protein content; when expressed as mIU/mg extract protein, the hCG concentrations ranged from 0.28 – > 18.2 mIU/mg protein. Comparison of oestrogen receptor and hCG presence in the tumours showed no strong correlation. All tumours in which hCG was detected were shown to be of ductal origin.
The hCG was measured by a β-chain specific radioimmunoassay which measures only hCG even in the presence of high levels of other gonadotrophin hormones. In further study of these specimens an immunoperoxidase staining technique was used to stain for hCG in formalin-fixed sections of the same tumours assayed by RIA. This technique confirmed hCG in the positive specimens examined (tissue was available for 7 of the 9 positives) and no significant staining in any negatives. The hCG was shown to be localized within the cytoplasm and on the surface of the malignant cells but not in surrounding normal cells. This intracellular localization demonstrates that the malignant cells may produce hCG, rather than stimulating the pituitary to do so.
Familial Cushing's syndrome with primary adrenocortical microadenomatosis (primary adrenocortical nodular dysplasia)
Authors: Schweizer-Cagianut M. , Froesch E. R. , Hedinger Chr. 
Published: December 2008

Abstract.
Cushing's syndrome was found in 2 of 4 siblings all of which also had other malformations. After bilateral adrenalectomy no hyperpigmentation was noted. Morphologically the adrenals of both siblings with Cushing's syndrome showed the typical lesions of the so-called microadenomatosis or primary adrenocortical nodular dysplasia with foci of eosinophilic giant cells. This is a new form of Cushing's syndrome due to an inborn error of the adrenals and no hypothalamicpituitary dysfunction.
Circadian rhythms in plasma levels of cortisol, dehydroepiandrosterone, Δ4-androstenedione, testosterone and dihydrotestosterone of healthy young men
Authors: Guignard Michel M. , Pesquies Pierre C. , Serrurier Bernard D. , Merino Danielle B. , Reinberg Alain E. 
Published: December 2008

Abstract.
Three healthy males (18, 22 and 30 years of age; 85 kg/177 cm, 82 kg/181 cm and 75 kg/168 cm, respectively), synchronized with a diurnal activity (06.00 to 23.00 h) and nocturnal rest, volunteered for this study. Blood was sampled (venous catheter) hourly during a 24 h span. A radiocompetition method was used for cortisol determinations. Other steroids were first extracted (ethyl-ether) from each plasma sample, then chromatographed on a celite column to isolate 3 fractions: 1) Δ4-androstenedione (Δ-4); 2) dihydrotestosterone (DHT) and dehydroepiandrosteone (DHA); 3) testosterone (T). A radioimmunological assay was used thereafter for the determination of androgenic steroids. Statistically significant (both conventional and cosinor methods) circadian rhythms were detected (P < 0.005). Acrophases (peak times) occurred in the following order: cortisol (07.28), DHA (08.43), Δ-4 (09.54), T (11.15) and DHT (16.37). The respective circadian amplitudes of DHA and Δ-4 were smaller than those of cortisol while the amplitudes T and DHT did not show differences statistically significant from each other.
Effects of pentobarbital on hypothalamic catecholamines and LRH activities
Authors: Kalra S. P. , Simpkins J. W. , Kalra P. S. 
Published: December 2008

Abstract.
Pentobarbital (Pnt) injection at 12.30 h to ovariectomized rats suppressed the LRH contents of the medial basal hypothalamus (MBH) in association with a significant fall in serum LH 60–90 min later. The LRH contents in the preoptic area (POA) were unchanged in Pnt treated rats. A similar effect on LRH levels in the MBH was also evident in ovariectomized rats pre-treated with oestradiol benzoate. Pnt administration rapidly reduced the noradrenergic (NE) turnover in the MBH and POA, whereas dopamine (DA) turnover was unaltered. These studies show that: (i) the apparent decrease in LRH secretion (release + contents) following Pnt treatment was associated with a fall in the hypothalamic NE neurotransmission, and (ii) LRH neurons and fibres in the MBH alone respond to Pnt treatment.