Influence of the pineal gland on the reproductive system of the male house mouse

Summary Procedures designed to express pineal-mediated antigonadotropic activity were performed upon male house mice. Neither blinding nor blinding plus olfactory bulbectomy of house mice resulted in testicular involution within 12 weeks. The pineal gland appears to be of little significance to reproduction in the house mouse.Supported by NICHHD grant No. HDO 7119-092.Supported by NICHHD grant No. 5P5 OHDO 8338.Supported by NSF grant No. SPI 7922 372.     

Mitotic activity in the glandular epithelium of the rat small intestine after electrothermocoagulation of the tubero-infundibular region of the hypothalamus and simultaneous resection of the pineal gland]

Radio-frequency lesions of the tubero-infundibular region of the hypothalamus and simultaneous pinealectomy are performed in rats. The double operation is followed by a significant increase of mitotic rate in the small intestine glandular epithelium. This increase is higher than the addition of the effects that are caused by each operation.     

Location of allatostatic centers in the pars lateralis regions of the brain of the Colorado potato beetle

Summary Selective lesions in the pars intercerebralis and pars lateralis areas of the brain of the adult Colorado potato beetle were produced by radiofrequency cautery. The effect of these lesions on the corpus allatum activity, determined by the short-term in vitro radiochemical assay, revealed that gland inhibitory centers are located in the pars lateralis.     

Variations of testosterone uptake by gonadotropic cells of the adenohypophysis of the rat

Testosterone (T) could be detected by immunocytochemistry after cryoultramicrotomy and T is likely bound on a binding site of a high affinity. Castration and adrenalectomy involve a swift disappearance of T in the gonadotropic cells. Synthesis of new binding sites was induced by daily T injection in the castrated and surrenalectomized Rat from 90 days. This synthesis is inhibited by cycloheximide. These data suggest that binding sites are proteins. The captation of T by the gonadotropic cells was diminished similarly at the diminution of T, afterwards, T captation was stabilized at a weak level which became stable for several weeks. It seems that immunocytochemistry permits the study of the variation of T captation by Rat pituitary gonadotropic cells.     

The accuracy of aminoacylation--ensuring the fidelity of the genetic code

The fidelity of protein biosynthesis rests not only on the proper interaction of the messenger RNA codon with the anticodon of the tRNA, but also on the correct attachment of amino acids to their corresponding (cognate) transfer RNA (tRNA) species. This process is catalyzed by the aminoacyl-tRNA synthetases which discriminate with remarkable selectivity amongst many structurally similar tRNAs. The basis for this highly specific recognition of tRNA by these enzymes (also referred to as 'tRNA identity') is currently being elucidated by genetic, biochemical and biophysical techniques. At least two factors are important in determining the accuracy of aminoacylation: a) 'identity elements' in tRNA denote nucleotides in certain positions crucial for protein interactions determining specificity, and b) the occurrence in vivo of competition between synthetases for a particular tRNA which may have ambiguous identity.     

Role of ACTH on the cytomorphology of testes of the immature rat

Summary The male gametogenic development of the immature rat shows inhibitory effect by the exogenous infusion of ACTH (0.25 IU and 0.50 IU; i.p.). Seminiferous tubular degeneration, Leydig cell atrophy and Sertoli cell regression are very conspicuous in the dosage of 0.50 IU ACTH (i.p.). Cytometrical and histological evidence confirms that ACTH could be inhibited by FSH during male gametogenic development which leads to cellular degeneration of testes in the immature rat.This work is supported by CSIR, Project No. JRF 37. We thank Md. K. Doubet for photomicrography.     

Influence of N-methylformamide on the development, the NAD synthesis, and the activity of the ADPR transferase of rat embryos

When N-methylformamide is administered to rats on the 11th day of pregnancy approximately 50% of the fetuses are resorbed and a reduced weight of the developed animals is found in comparison to the controls on the 21th day (delivery by Caesarian section). The toxic effect is increased by using nicotinamide and methionine. If a combination of these substances is employed practically all fetuses are resorbed. Tryptophan, however, has a considerably protective influence. N-Methylformamide has no influence on the NAD-synthesis induced by nicotinamide or tryptophan. It does, however, inhibits the activity of the ADPR transferase.     

The American Philosophical Society and the rise of astronomy in the United States in the middle of the nineteenth century

Early geological investigations in the St David's area (Pembrokeshire) are described, particularly the work of Murchison. In a reconnaissance survey in 1835, he regarded a ridge of rocks at St David's as intrusive in unfossiliferous Cambrian; and the early Survey mapping (chiefly the work of Aveline and Ramsay) was conducted on that assumption, leading to the publication of maps in 1845 and 1857. The latter represented the margins of the St David's ridge as ‘Altered Cambrian’. So the supposedly intrusive ‘syenite’ was regarded as younger, and there was no Precambrian. These views were challenged by a local doctor, Henry Hicks, who developed an idea of the ex-Survey palaeontologist John Salter that the rocks of the ridge were stratified and had formed a Precambrian island, round which Cambrian sediments (now confirmed by fossil discoveries) had been deposited. Hicks subsequently proposed subdivision of his Precambrian into ‘Dimetian’, ‘Pebidian’, and (later) ‘Arvonian’, and he attempted correlations with rocks in Shropshire, North Wales, and even North America, seeking to develop the neo-Neptunist ideas of Sterry Hunt. The challenge to the Survey's work was countered in the 1880s by the Director General, Geikie, who showed that Hicks's idea of stratification in the Dimetian was mistaken. A heated controversy developed, several amateur geologists, supported by a group of Cambridge Sedgwickians, forming a coalition of ‘Archaeans’ against the Survey. Geikie was supported by Lloyd Morgan. Attention focused particularly on Ogof Lle-sugn Cave and St Non's Arch, with theory/controversy-ladenness of observations evident on both sides. Evidence from an eyewitness student record of a Geological Society meeting reveals the ‘sanit`ized’ nature of the official summary of the debate in QJGS. Field mapping early in the twentieth century by J. F. N. Green allowed a compromise consensus to be achieved, but Green's evidence for unconformity between the Cambrian and the Dimetian, obtained by excavation, can no longer be verified, and his consensual history of the area may need revision. Unconformity between the Cambrian and the Pebidian tuffs is not in doubt, however, and Precambrian at St David's is accepted. The study exhibits features of geological controversy and the British geological community in the nineteenth century. It also furnishes a further instance of the great influence of Murchison in nineteenth-century British geology and the side-effects of his controversy with Sedgwick.     

Correlations between the neurobiology of colour vision and the psycholinguistics of colour naming.

Neurobiological experiments demonstrate that colour sensation is perceived by the brain by processes which, in principle, follow the opponent colour pairs scheme proposed by Hering in 1874. Tests on colour naming in various European, Asian and Central American languages have shown that the opponent scheme is also reflected in psycholinguistics. The linguistic evolution of colour terms proposed by Berlin and Kay (1969) is correlated directly with the ontogenetic development of language in children as elucidated by Jakobson (1941). Colour vision is therefore a suitable field for interdisciplinary investigations of brain processes and linguistics.     

Correlations between the neurobiology of colour vision and the psycholinguistics of colour naming

Summary Neurobiological experiments demonstrate that colour sensation is perceived by the brain by processes which, in principle, follow the opponent colour pairs scheme proposed by Hering in 1874. Tests on colour naming in various European, Asian and Central American languages have shown that the opponent scheme is also reflected in psycholinguistics. The linguistic evolution of colour terms proposed by Berlin and Kay (1969) is correlated directly with the ontogenetic development of language in children as elucidated by Jakobson (1941). Colour vision is therefore a suitable field for interdisciplinary investigations of brain processes and linguistics.Dedicated to Prof. Roman Jakobson, Cambridge, Mass.Acknowledgment. I thank Prof. Roman Jakobson, Harvard University and M.I.T., Cambridge (Mass.) and Prof. Elmar Holenstein, Ruhr-Universität, Bochum, Germany (formerly University of Zurich, Switzerland) for many stimulating discussions.     

On the genesis of the soil mantle of the region of Manaus,Central Amazonia,Brazil

Summary The dynamics of the forest to the north of Manaus is tightly linked to that of the soil. The latosol that covers the plateau, which supports a dense forest, consists from top to bottom of: (a) a brown, clayey organic horizon (0.3 m), (b) a yellow horizon, very rich in clay but permeable (from 0.3 to 4 m), (c) a nodular horizon rich in Al and Fe oxides (from 4 to 9 m), and (d) a horizon which still preserves the sedimentary structures of the parent sandstone, where quartz is intensely dissolved and kaolinite crystallizes in pores. In perfectly flat areas, the clay of the organic horizon is destroyed by acidocomplexolysis, and the dissolved Al is transported vertically by the drainage water. A part of this Al is used to make the gibbsite nodules of horizon (c), and the rest is used to make kaolinite in horizon (d). Because aluminum is thus conserved within any vertical prism, the rate of destruction of horizon (a) is equivalent to the rate of advance of the kaolinization zone into the sediment: the latosol is said to be in equilibrium, the surface remains perfectly flat as it slowly sinks, the quantity of kaolinite increases with time, and the silica released by quartz dissolution in the whole profile is exported by drainage water to the water table. In contrast, near drainage axes, however small initially, the drainage becomes inclined toward the axis. Part of the Al released by acidocomplexolysis of horizon (a) is now exported to rivers, and Al is no longer conserved within any given prism. The rate of advance of the kaolinization zone (d) into the sediment now becomes less than the rate of destruction of horizon (a) and the surface sinks faster than that of the surrounding plateau. After this differential podzolization has gone on long enough, it creates a network of geochemical valleys characterized by convex slopes and bounded by sandy soils (campinas). The vegetation becomes sparser and sparser. At the end, only some bushes and lichens survive on the white sand.Acknowledgments. The authors are indebted to Dr E. Merino (Dept. of Geology, Indiana University) for helpful criticisms and suggestions. This research was carried out in I.N.P.A. (Instituto Nacional de Pesquisas da Amazonia) and was financially supported by the CNPq-CNRS/ORSTOM conv.     

Evidence for the induction and release of pancreatic folylpolyglutamate hydrolase by the ingestion of folyl polyglutamates in the rat

Pteroyl polyglutamate hydrolase (folyl conjugase), which hydrolyses the dietary polyglutamyl folates into simple forms prior to absorption, has been shown to be induced in rat pancreas in response to dietary polyglutamyl folates but not by ingestion of synthetic unconjugated folates. Folate absorption, as measured by the rise in serum folate levels after ingestion, of dietary conjugated folates is impaired in pancreatectomised animals whereas absorption of synthetic simple folate is not. A severe build-up of folyl conjugase is observed in the lumen of control but not in pancreatectomised animals after dietary folate ingestion. These results taken together would suggest that dietary folates are hydrolysed to monoglutamyl forms suitable for absorption in the lumen; the hydrolysis is catalysed by a luminal folyl conjugase of pancreatic origin induced by dietary conjugated folates.     

On the normative dimension of the St. Petersburg paradox

In this paper I offer an account of the normative dimension implicit in D. Bernoulli’s expected utility functions by means of an analysis of the juridical metaphors upon which the concept of mathematical expectation was moulded. Following a suggestion by the late E. Coumet, I show how this concept incorporated a certain standard of justice which was put in question by the St. Petersburg paradox. I contend that Bernoulli would have solved it by introducing an alternative normative criterion rather than a positive model of decision making processes.     

Changes in the distribution of gamma-glutamyl transferase in the organs of the mouse as a function of development]

In the Mouse, gamma-glutamyl transferase distribution changes with development in the kidney and the liver; on the contrary, its activity remains almost equal and low in other organs. In the liver, a low activity is observed in the fetus and the new-born up to the 3rd day of life; then it is no more measurable. In the kidney, the low enzyme activity of the fetus is multiplied by 10 in the 10 first days of life and by 50 in the 6 first weeks.     

Some thoughts on the importance of insulin in the regulation of the blood glucose level

Insulin can influence rates of glucose utilization by muscle and possibly other tissues via both direct and indirect effects. It can control the rate of fatty acid mobilization from adipose tissue and the rate of fatty acid oxidation in muscle, and the latter inhibits glucose utilization and oxidation. Insulin may influence the levels of insulin-like growth factors I and II, both of which have effects on rates of glucose utilization by muscle. The intertissue cycle between glucose and lactate — the Cori cycle, which is influenced by insulin — may provide another novel mechanism for control of blood glucose. How far other anti-insulin hormones affect these processes is not clear.     

Stimulation of the incorporation of3H-leucine into proteins by oestradiol in the foetal uterus of the guinea-pig

Summary Oestradiol treatment increases the incorporation of³H-leucine into acid insoluble proteins in the foetal guineapig uterus (50–65 days of gestation) 10 times above control values by 8 h and 20 times by 24 h after administration of oestradiol to the mother.     

Effects of selective removal of the salivary glands on taste bud cells in the vallate papilla of the rat

Summary The in-block removal of the main salivary glands produced a significant increase in the rate of development of the intermediate type of taste bud cells. Such effect was reproduced by removal of submaxillary-sublingual glands. Removal of parotid glands was not effective.Supported by a CAIT grant No. 1776.     

On the epistemological foundations of the law of the lever

In this paper I challenge Paolo Palmieri’s reading of the Mach—Vailati debate on Archimedes’ proof of the law of the lever. I argue that the actual import of the debate concerns the possible epistemic (as opposed to merely pragmatic) role of mathematical arguments in empirical physics, and that construed in this light Vailati carries the upper hand. This claim is defended by showing that Archimedes’ proof of the law of the lever is not a way of appealing to a non-empirical source of information, but a way of explicating the mathematical structure that can represent the empirical information at our disposal in the most general way.     

Suppression of the immune response by drugs interfering with the metabolism of serotonin

Summary The work was based on the assumption that neurohumoral control of the immune response, particularly in stressed animals, involves central serotoninergic mechanisms. Rats immunized with sheep erythrocytes were stressed by repeated restraints and/or treated with a precursor of serotonin (5-hydroxytryptophan, 5-HTP) or with an inhibitor of serotonin synthesis (parachlorophenylalanine, PCPA). As expected, repeated stresses reduced the plaque-forming cell (PFC) response. Treatment with 5-HTP also reduced the PFC response, and potentiated the immunosuppressive effect of stress. This was accompanied by increased metabolism of serotonin in the brain, as indicated by increased concentration of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in cerebral tissue. Treatment with PCPA also suppressed the PFC response, but this suppression was accompanied by decreased levels of brain serotonin and of 5-HIAA. Plasma corticosterone levels were elevated in rats treated with PCPA. It seems that putative central effects of PCPA on serotoninergic regulation of the immune response were outweighed by its effects on corticosterone secretion and/or on lymphoid cells.     

Effects of lesions of the anterior raphe nuclei on the self-administration of d-amphetamine in the rat : considerable increase of desire for the poison

The acquisition of the intravenous self-administration of d-amphetamine was studied after separate lesions of anterior raphe nuclei (dorsal or median). Every lever-press delivered 2.5 microliter of a d-amphetamine solution dosed at 7.5 microgram/kg. Lesion of anterior raphe nuclei produced an hyper-sensitivity to d-amphetamine as indicated by a dramatic increase in self-administration by experimental Rats compared to the controls. Moreover this enhanced self-administration behavior is observed with a low blood concentration of d-amphetamine. The greater increase was obtained for median raphe lesioned Rats. These effects are interpreted in terms of 5HT-DA balance and could provide an experimental model for neurobiological bases of drug addiction studies.