摘要:

SUMMARYIn vitrobiosynthesis of oestrogens in microsomal and 10000 g supernatant fractions of placentae, ten each, from normal and toxaemic pregnancies has been investigated. Dehydroepiandrosterone sulphate (DHAS), dehydroepiandrosterone (DHA) and androstenedione were used as substrates and their conversion to oestrone and oestradiol studied. In all the placental preparations the relative efficiency of the conversion of these androgens to oestrogens, though differing greatly between subcellular fractions as well as between normal and toxaemic placentae, was invariably in the order of DHAS>DHA>androstenedione. The conversion of these androgen precursors to oestrone and oestradiol was reduced in toxaemia compared with the normal placenta. Moreover, formation of oestradiol was much more reduced than that of oestrone. The free oestradiol level in the serum was also found to be lower in toxaemic pregnancies as compared with the normal range. The inter‐conversions of oestrogens further showed a significantly reduced conversion of oestrone to oestradiol in toxaemic placentae compared with normal placentae. The results may explain the lowered blood oestradiol levels observed in toxaemia of pregnancy and thus provide an explanation of the usefulness of the estimation of the oestradiol level as an index of feto‐placental funct

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01542.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SUMMARYThein vitrosteroid metabolism of testicular tissue from seven cases of testicular feminization was studied. Using radioactive steroid substrates of both C21and C19configurations, kinetic studies of these tissues showed that the major pathway of testosterone production was via the Δ5pathway, i.e. pregnenolone → 17α‐hydroxy‐pregneolone → dehydroepiandrosterone → androstenedione and androstenediol → testosterone, with the accumulation of dehydroepiandrosterone and androstenediol. This accumulation of dehydroepiandrosterone and androstenediol does not occur in similar incubations of normal human testis tissue.The seven cases of testicular feminization were classified as ‘complete’ or ‘incomplete’ forms of the syndrome by reference to clinical data and the histology of the testicular tissue. It was concluded that the biochemical differences between the two forms of the syndrome were the greater production and accumulation of C21and C19Δ4steroids from the C21and C19Δ5steroid precursors indicating the relatively greater activity of the C21‐3β‐hydroxysteroid dehydrogenase‐isomerase e

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01543.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SUMMARYTwo patients remained clinically euthyroid following treatment for thyrotoxicosis with antithyroid drugs in spite of persistently elevated thyroid radioiodine uptakes not suppressable by exogenous triiodothyronine. Perchlorate discharge tests showed a defect in the intrathyroidal organification of iodine. Circulating levels of thyroxine were normal. From our study of 105 patients treated for thyrotoxicosis with antithyroid drugs, apparent remission of thyrotoxicosis by this mechanism might occur in up to 2% of patients.

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01544.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryThe thyroids of two brothers aged 13 and 15 with congenital goitre, butanolinsoluble iodine in blood and which had pronounced decrease of immunoreactive thyroglobulin content in the thyroid were studied. Two types of thyroglobulin were identified. The first amounted to only about 200‐300 μg/g wet tissue and was fully immunoreactive with anti normal human thyroglobulin antiserum (iTG‐G). It was purified by affinity chromatography. The other was mainly associated with intracytoplasmic membranes, amounted to about 8 mg/g wet tissue and was only partially immunoreactive (piTG‐G). Both had abnormal amino acid compositions but only iTG‐G showed a decreased carbohydrate content. Surprisingly, piTG‐G showed a normal iodination level (0.5%) and a normal iodoamino acid composition. Immunochemical studies performed on slices or cell‐free fractions incubated in the presence of labelled amino acids and /or monosaccharides showed that: (1) thyroglobulin peptide chains were being synthesized and almost normally discharged into the cisternae of the rough endoplasmic reticulum; (2) incorporation of sugars into iTG‐G was decreased; (3) sialyl‐ and galactosyltranserase activities were normal and the enzymes normally located, and (4) albumin which is present in the thyroid as the iodinated protein was probably not synthesized by the goitrous tissues. Two major abnormalities were detected by light and electron microscopy: absence or pronounced scarcity of colloid in the follicular lumina and over distended endoplasmic reticulum cisternae. These observations are compatible with a defect in TG transport from the cell into the lumen as the cause of the goitre. Whether defective thyroglobulin export is basically related to abnormality of the protein structure or to another ca

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01545.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SUMMARYA patient with an intrathoracic fibrosarcoma in whom disabling hypoglycaemic episodes occurred is reported. No further hypoglycaemic episodes occurred following removal of the tumour. The mechanism of the hypoglycaemia associated with non‐pancreatic tumours is discussed. It seems that inadequate hepatic glucose output was an important factor in contributing to the hypoglycaemia in this patien

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01546.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SUMMARYSome 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 hyper‐gonadotrophic 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 hypogonadis

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01547.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SUMMARYLH and FSH were assayed in serum samples from children ranging from newborn to 13 years. In boys, LH was found in most samples up to 4 months of age, in many up to 10 months, but in only 38% between 1 and 8 years. In girls, it was found in only 29% of the samples under 1 year and the frequency and concentration changed little thereafter until 8‐10 years. FSH was detected in all samples from boys up to 4 months and in most of those from girls up to 2 years. After these ages the frequency declined in each sex and there was little further change until 8‐10 years. Between 1 and 8 years the proportion of samples containing either FSH or LH was similar for the two sexes, but whereas in boys high LH tended to be associated with high FSH, and vice versa, there was no such correlation in girls. The results are discussed in relation to gonadal development and steroid synthe

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01548.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SUMMARYThe urine clearance of TRH after intravenous injection in man has been measured by radioimmunoassay. Between 4.4% and 10.7% of the dose was excreted within 90 min, the majority within 30 min. The TRH excreted was immunochemically and chromatographically indistiguishable from synthetic TRH and was inactivated by plasma enzymes with the same kinetic characteristics. The immunoreactive TRH‐like material in basal urine samples was not TRH however: chromato‐graphically and enzymatically it behaved differently from the synthetic tripept

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01549.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SUMMARYA metabolic study with tissue from a virilizing arrhenoblastoma, using as precursors [7‐3H]pregnenolone, [7‐3H]17α‐hydroxypregnenolone, [4‐14C]17α‐hydroxy‐progesterone and [4‐14C]testosterone, revealed that in spite of a deficient activity of 3β‐hydroxysteroid dehydrogenase‐5‐isomerase the overall production of test‐osterone was compensated by an increased activity of a lyase converting[4‐14C]17α‐hydroxyprogesterone to testosterone (via androstenedione) and was comparable to the production obtained by normal ovarian tissue. The masculinizing effects of the tumour invivowere most probably caused by accumulation of testosterone due to deficiencies in enzymes catabolizing testosterone to 17‐ketosteroids and its aromatization to oestrogen. The unique property of the arrhenoblastoma to convert [4‐14C]17α‐hydroxyprogesterone to [4‐14C]11‐deoxycortisol (Reichstein's compound S) suggests an adrenal origin of the tumour which may explain its li

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01550.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SUMMARYSerum thyrotrophin response to thyrotrophin releasing hormone was impaired in all of eight subjects with untreated Cushing's disease; while all of six similar subjects tested after adequate treatment by a pituitary implant of198Au then showed a normal response. In all five of the untreated patients studied, the serum prolactin response to TRH was normal. Thus chronically excessive cortisol levels as seen in Cushing's disease inhibit pituitary TSH responsiveness to TRH without affecting the prolactin response to TRHEvidently the release of TSH and of prolactin by TRH are governed by independent mechanisms.

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1975.tb01551.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY