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J. W. DOBBIE and T. SYMINGTON

SUMMARY

The internal anatomy, particularly the vasculature, of the human adrenal was investigated with the help of three-dimensional reconstruction models supplemented by stereo-angiography. A definite pattern of positional relationship was shown to exist between the cortex, medulla and venous drainage, and on this basis the adrenal should be considered as a tripartite structure consisting of a head, a body and a tail region. The disposition of the longitudinal muscle bundles in the adrenal veins follows a definite pattern in each region of the gland. The muscular veins lie almost entirely within sleeves of cortical tissue. The selective gathering of the muscle bundles into the medulla-facing segment of the veins in certain regions of the gland is described. The effect of this muscular arrangement on the venous sinuses which pass between the muscle bundles was investigated and considered to be one of closure. Elastic tissue was demonstrated in the medullary venous sinuses; it is suggested that together with the muscle bundles both constitute a musculo-elastic organ capable of intermittent explosive release of hormones from the venous sinuses into the central vein. The hitherto neglected effect of the unique venous sytem on the function of the cortex was examined. Its possible role in the morphological changes of the adult cortex in response to stress, adrenocorticotrophic hormone, and in adrenal pathology is considered.

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C Nilsson, M Seppala and K Pettersson

Immunoassays are widely used for measuring gonadotropins, including luteinizing hormone (LH), as these are both specific and sensitive. Because LH is microheterogeneous it has been claimed that the specificity of monoclonal antibodies used in two-site immunoassays can limit their clinical utility. Furthermore, we reported earlier a common genetic variant form of LH due to amino acid alterations in the LHbeta gene that is poorly or not recognized by antibodies directed against epitopes present in the intact molecule. We here report the result of an LH epitope mapping using 30 different monoclonal antibodies. The antigenic area affected by the amino acid alterations is fairly large, as antibodies to the two intact domains are able to sandwich each other. Combinations of alpha-beta or beta-beta antibodies generally provide alternatives for unbiased detection of circulating LH and some have reasonably good discrimination of human chorionic gonadotropin. The beta-beta combinations exhibit a peculiarity in urine determinations as they detect the urinary beta-core fragment. Our aims were to study the altered immunoreactivity caused by the amino acid changes and to design two-site LH assays fully capable of recognizing the biologically active LH variant. We also conclude that the variability in recognizing the universally occurring LH variant is the most important factor contributing to the widely documented LH immunoassay discrepancies.

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R. WILKINSON, R. HALL, A. COOPER and D. J. NEWELL

SUMMARY

Plasma non-esterified fatty acid (NEFA) levels during a standard insulin sensitivity test have been compared in hypopituitary and hospital control patients who had undergone full routine pituitary investigations. Significant impairment of the recovery of plasma NEFA levels after insulin injection was found in the hypopituitary group as a whole, but this finding was not consistent in individual cases. It is concluded that the measurement of NEFA levels is of little value in the diagnosis of mild hypopituitarism. Blood sugar levels after insulin were of no value in the diagnosis of minor degrees of hypopituitarism.

In 19 patients with mild hypopituitarism the order of frequency of deficiency of individual hormones, as judged by tests currently available, was gonadotrophins followed by growth hormone, adrenocorticotrophic hormone, thyroid-stimulating hormone, and antidiuretic hormone.

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J. A. LORAINE and MARIE A. MACKAY

SUMMARY

Pooled urine from normal men, normally menstruating women and hospitalized postmenopausal subjects was extracted by six published methods and assayed for human pituitary gonadotrophic (HPG) activity by the mouse uterus test in terms of HMG-20A.

In the three types of urine studied comparable yields of HPG were obtained by all six extraction methods, and an analysis of variance showed the absence of significant differences between the methods.

No evidence could be obtained to support previous claims that the kaolinacetone method of Loraine & Brown (1959) gave less satisfactory yields of urinary HPG than certain of the other procedures.

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THOMAS McKEOWN and R. G. RECORD

1. The association between placental and foetal weights in man is examined in 4931 single and 834 twin maternities.

2. After 30 to 31 weeks' gestation, both foetuses and placentae are heavier in single than in twin pregnancy (see Table 1).

3. At the same placental weights singletons are heavier than twins. The difference in foetal weights is reduced, but not eliminated, by standardization of the means to correct for differences in distribution by duration of gestation (Fig. 2).

4. It is concluded that in man something more than the difference in placental weight is required to explain the difference between growth rates of twins and singletons in late pregnancy. Data published by Ibsen [1928] are used to show that in the guinea-pig also, retardation of foetal growth in large litters cannot wholly be attributed to variation in placental size (Fig. 4).

5. Mean weekly increment in weight of singletons between birth and 3 months (0·49 lb.) is almost identical with that of single foetuses between 30 and 36 weeks gestation (0·48 lb.), when foetal growth is linear. This suggests that the retardation of growth of the single foetus (from about 37 weeks) is determined, as in multiple pregnancy, by the inability of the pre-natal environment fully to meet the needs of the foetus, rather than by the inability of the foetus to maintain its rate of growth.

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N. G. B. McLETCHIE

Pathological abnormality in the basophil cells of the human hypophysis in cases of Cushing's syndrome may be very complex. A single basophil cell may show areas of normal granularity, areas of refractile hyaline cytoplasm (of Crooke), normal granules dispersed around vacuoles, conglomerations of small vacuoles outlined by delicate refractile cytoplasmic threads, one or more nuclei pressed out as a fine rind and scalloped by the vacuoles, and cytoplasmic processes extending out and embracing surrounding cells [McLetchie, 1944]. Though it may be that all this complexity is easily analysed in fresh material, this is not so in material 12–30 hr. post mortem, with which I, and most morbid anatomists, have to deal.

I have found that if a stain is specific for β (basophil) granules then the hyaline cytoplasm of Crooke will appear unstained. While under certain conditions many dyes (iron and chrome haematoxylins, acid fuchsin, aniline blue, methyl blue, crystal

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M. SALMENPERÄ, A. I. KAHRI and A. SAURE

SUMMARY

The effects of corticosterone in concentrations found in adrenal venous plasma on ACTH-induced changes in cultured cortical cells derived from foetal rat adrenals were studied. Corticosterone at a concentration of 5·7 × 10−5 mol/l completely inhibited mitochondrial differentiation to fasciculate-like morphology. The same cultures revealed significant inhibition of 11β- and 18-hydroxylation compared with cultures treated with ACTH only. This was shown by the reduced formation of corticosterone and 18-OH-deoxycorticosterone (48%, P < 0·001) and simultaneous enhancement of deoxycorticosterone formation (33%, P < 0·05) from added [4-14C]progesterone. Similar inhibition was observed when dibutyryl cyclic AMP replaced ACTH as an inducer of differentiation. Lower concentrations of corticosterone (1·2 × 10−5 and 2·4 × 10−5 mol/l) inhibited ACTH-stimulated formation of corticosterone and 18-OH-deoxycorticosterone from endogenous precursors.

The results demonstrate that corticosterone regulates the stage of differentiation in cultured adrenocortical cells. The possible role of corticosterone in the regulation of growth and steroidogenic capacity of the adrenal cortex is discussed.

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D. B. Gower and B. A. Ruparelia

Introduction

While investigating the presence and function of androgens in pigs, Prelog & Ruzicka (1944) found an abundance of 16-androstenes in boar testes. The alcohols of this series of steroids, such as 5α-androst-16-en-3α-ol (3α-androstenol) (Fig. 1) were recorded as possessing musk-like odours (for review see Ohloff et al. 1983) while the corresponding ketones, such as 5α-androst-16-en-3-one (5α-androstenone), had a 'urine-like' smell (Prelog et al. 1945). Prior to this finding, investigators had reported an unpleasant odour originating from cooking the meat from a mature boar and the odour was thought to arise either from the parotid or submaxillary glands. Subsequent studies showed that this 'boar-taint', as it is called, comprises 5α-androstenone and 3α-androstenol (Patterson, 1968a,b; Claus, 1974; Bonneau, 1982; Booth, 1982) and, possibly, other 16-androstenes. As a result of numerous experiments, both in vitro and in vivo, the source of these 16-androstenes is known to be largely the testis in pigs,