The influence of somatostatin on drug-induced prolactin release in the monkey

Summary The infusion of linear somatostatin did not block prolactin release induced by either perphenazine, TRH or serotonin. Somatostatin infusion, however, potentiated prolactin release induced by perphenazine and TRH but not that induced by serotonin.Supported in part by NIH General Research Support Grant No. RR5384 to Wayne State University School of Medicine and by NIH Research Grant No. HDO7722.The authors wish to express their appreciation to Mrs.Cynthia Van De Walle for her outstanding technical assistance in the performance of the prolactin RIA and the statistical analyses. We also appreciate receiving linear somatostatin from Dr.R. Makineni, Bachem Inc., Marina Del Ray, California, USA and from Dr.N. H. Grant, Wyeth Laboratories, Philadelphia, Pa. USA. We would like to thank Abbott Laboratories, North Chicago, Ill. USA for the gift of TRH and the Schering Corp., Bloomfield, N.J. USA for the gift of perphenazine.     

Tremorogenic effect of thyrotropin releasing hormone in rats

Zusammenfassung Thyrotropin-Releasing Hormon (TRH) erzeugt unmittelbar nach i.v. Injektion an Pentobarbital-narkotisierten Ratten einen feinschlägigen Tremor und Haarsträuben. Diese Symptome werden durch eine direkte zentralnervöse Wirkung von TRH und nicht durch Stimulation der Schilddrüse ausgelöst. Die Wirkung ist dosisabhängig und spezifisch für das Tripeptid pGlu-His-Pro.

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Acknowledgments. The authors gratefully acknowledge the advice of Dr.P. A. Desaulles and Dr.W. Rittel and the skilled technical assistance of Mr.B. Latscha and Mr.J. C. Dalmer.     

On the time course of thyrotropin suppression by high doses of thyroid hormones

Summary Basal and stimulated TSH decreased progressively. Basal TSH was suppressed below the detection limit of 0.4 U/ml after 74 h in 2 of the T₃ and all of the T₄ treated indiduals. At this time, in both groups 3 individuals could be significantly stimulated by TRH (about 5% of the pretreatment stimulation). There was no significant difference in the time course of suppression obtained by T₃ or T₄, though plasma T₃ levels in the T₄ treated group were considerably lower.Supported by the Deutsche ForschungsgemeinschaftThe excellent technical assistance of MissM. Knöpfle, MissU. Neun and Mr.G. Magin is gratefully acknowledged.     

Thyrotropin-releasing hormone does not inhibit lysine vasopressin-induced growth hormone secretion in normal men

Summary In order to establish whether thyrotropin-releasing hormone (TRH) inhibits lysine-vasopressin (LVP)-induced growth hormone (GH) release, six normal men were tested with LVP alone or in combination with TRH. LVP strikingly increased serum GH levels; this response was not altered by TRH. These results indicated that in man TRH is not involved in the control of GH secretion in response to LVP.     

Development and evaluation of a method of high pressure liquid chromatography for the determination of the level of degradation of thyroliberin (TRH) in blood]

The degradation of the TRH by plasma was studied using a sensitive method for the separation of TRH and products formed by high-pressure liquid chromatographic analysis (HPLC). The detected products are TRH-3H or synthetic TRH. The HPLC analysis is performed on a microparticulate (10 mu) silica gel chromatographic column with CH3CN/0,01 M NH4OAc, at pH 6 (30/70) (V/V). This technique provides a good separation of TRH and the other products of degradation. In our experimental conditions, the human plasma degrades 62.5 +/- 5% of of TRH in 60 mn; very similar results are obtained with thin layer chromatography.     

Thyrotropin-releasing hormone does not inhibit lysine vasopressin-induced growth hormone secretion in normal men

In order to establish whether thyrotropin-releasing hormone (TRH) inhibits lysine-vasopressin (LVP)-induced growth hormone (GH) release, six normal men were tested with LVP alone or in combination with TRH. LVP strikingly increased serum GH levels; this response was not altered by TRH. These results indicate that in man TRH is not involved in the control of GH secretion in response to LVP.     

Thermogenic effects of thyrotrophin-releasing hormone and its analogues in the rat

Summary Acute or chronic injection of RX 77368 (a TRH analogue; 1 mg/kg s.c.) stimulated oxygen consumption (VO₂) and brown adipose tissue activity in the rat, and decreased weight gain Other TRH analogues (CG 3509, RGH 2202) and TRH itself also stimulated VO₂. These thermogenic actions are probably mediated centrally by stimulation of sympathetic outflow to brown fat.     

Thermogenic effects of thyrotrophin-releasing hormone and its analogues in the rat

Acute or chronic injection of RX 77,368 (a TRH analogue; 1 mg/kg s.c.) stimulated oxygen consumption (VO2) and brown adipose tissue activity in the rat, and decreased weight gain. Other TRH analogues (CG 3509, RGH 2202) and TRH itself also stimulated VO2. These thermogenic actions are probably mediated centrally by stimulation of sympathetic outflow to brown fat.     

Laser diffraction used to monitor strain in mechanoreceptors ofJasus verreauxi

Summary Laser diffraction patterns from crayfish abdominal mechanoreceptors have been observed and the corresponding sarcomere lengths calculated and then correlated with sensory nerve discharge frequencies.Our thanks are due to the Australian Research Grants Committee for provision of the lasers and camera, to Dr.K. S. Imrie for the design of the interfacing cards, to ProfessorP. Mason and ProfessorR. E. Aitchison for their encouragement and advice, and toI. Paterson andC. March for constructing the equipement.     

Eco-physiological studies onZornia diphylla pers. with reference to adaptive seed dormancy

Summary Seeds ofZornia diphylla possess a complex type of dormancy which is of great survival value for the species. Seeds show polymorphism. The optimum temperature for germination explains the cause of its distribution in the tropics. The grazing and scraping promotes the vegetative growth.The author is grateful to Dr.R. Sahai and Dr.R. S. Tripathi, Gorakhpur University, for guidance and to Dr.Y. B. Singh, Principal, and Dr.G. C. Srivastava, Head Dept. Botany, for encouragement and facilities. Thanks are due to my colleagues late SriP. N. Gupta, SriJ. Abraham, SriF. Abbasi, and Dr.A. B. Sinha for their cooperation.     

Newton's early computational method for dynamics

On December 13, 1679Newton sent a letter toHooke on orbital motion for central forces, which contains a drawing showing an orbit for a constant value of the force. This letter is of great importance, because it reveals the state ofNewton's development of dynamics at that time. Since the first publication of this letter in 1929,Newton's method of constructing this orbit has remained a puzzle particularly because he apparently made a considerable error in the angle between successive apogees of this orbit. In fact, it is shown here thatNewton's implicitcomputation of this orbit is quite good, and that the error in the angle is due mainly toan error of drawing in joining two segments of the oribit, whichNewton related by areflection symmetry. In addition, in the letterNewton describes quite correctly the geometrical nature of orbits under the action of central forces (accelerations) which increase with decreasing distance from the center. An iterative computational method to evaluate orbits for central forces is described, which is based onNewton's mathematical development of the concept of curvature started in 1664. This method accounts very well for the orbit obtained byNewton for a constant central force, and it gives convergent results even for forces which diverge at the center, which are discussed correctly inNewton's letterwithout usingKepler's law of areas.Newton found the relation of this law to general central forces only after his correspondence withHooke. The curvature method leads to an equation of motion whichNewton could have solvedanalytically to find that motion on a conic section with a radial force directed towards a focus implies an inverse square force, and that motion on a logarithmic spiral implies an inverse cube force.     

Paroxysmal discharges in the electroencephalogram of the El mouse

Summary The spike discharges in the EEG of the El mouse, a seizure-susceptible strain, were recorded during convulsive seizures. This fact provides evidence that those seizures are really epileptic convulsions.I thank Dr.K. Imaizumi and Dr.K. Nakano of National Institute of Health for their sharing the strain of El mouse to us and MissY. Nakamoto and Mr.N. Ozawa for their technical assistance and Mr.K. Moriyama for his care for the mice, and also thank Dr. H.Narabayashi for his criticism on this paper.     

Diketopiperazines containing L-proline from Streptomyces lavendulae and their stereochemistry in solution

Summary l-Valyl-l-proline (I),l-leucyl-l-proline (II),l-phenylalanyl-l-proline (III) andl-isoleucyl-l-proline (IV) anhydrides were isolated from the cultures ofStreptomyces lavendulae No. 314 and, on the basis of¹³C-NMR and CD spectra, their stereochemistry in solution is described.Acknowledgments. The authors would like to express their sincere thanks to Prof. H. Ogura, Kitasato University, for kind supply of the authenticl-valyl-l-proline anhydride and to Mr. A. Takakuwa, JASCO, for measuring the CD curves with J-40 automatic recording spectropolarimeter.     

Über den Einbau von Dipeptiden in Ergotoxin-Alkaloide

Summary l-Valyl-l-leucine-U-¹⁴C,l-valyl-l-proline-U-¹⁴C-lactam andl-leucyl-l-proline-U-¹⁴C-lactam were administered to submerged cultures of an ergotoxine-mixture-producing strain ofClaviceps purpurea. The added dipeptides were split by the fungus into the corresponding amino acids prior to incorporation. Apparently dipeptides are no immediate precursors for the peptide side-chain of ergotoxinealkaloids.     

Localization of bovine pancreatic polypeptide (BPP)-like immunoreactivity in rat pancreatic monolayer culture

Summary Antiserum to bovine pancreatic polypeptide (BPP) has been used for immunofluorescent staining in the light microscope. With this technique it is possible to detect the presence of specific cells in monolayer culture from neonatal rat pancreas which contain BPP or a closely related peptide.This work was supported by a grant (No. 3.553.75) from the Fonds National Suisse de la Recherche Scientifique. We are very grateful to Dr.R. E. Chance, Eli Lilly, for his generous gift of BPP and anti-BPP serum. We are also very obliged to Dr.R. H. Unger for providing glucagon, to Dr.J. Rivier and Dr.R. Guillemin for somatostatin, to Dr.N. Yanaihara for secretin, to Dr.W. Gepts for gastrin and to Dr.A. J. Moody for GLI.     

The conceptual import of Carnot's theorem to the discovery of the entropy

Summary Among many other things, Carnot stated a principle and proved a theorem. In 1850, Clausius corrected Carnot's theory, modifying it according to Joule's principle. He might have considered a corollary of the theorem as the mathematical formulation of Carnot's principle. We challenge the corollary: it is based on hidden assumptions, nor is it true for all cycles. Clausius realized the corollary's lack of generality, but on different grounds. In 1854, he generalized the theorem, and gave an (other) expression to Carnot's principle. We analyze Clapeyron's account of Carnot's theory, Thomson's account of 1849 and some of Clausius belated comments on his 1850 paper, as well Clausius' paper of 1854. We hope that they shed light on the corollary's tacit hypotheses and on the meaning of Carnot's principle. It is our contention: Clausius took seriously a contemporary meaning of the principle, and looked for a condition of integrability that could express recovery of the initial conditions of the reservoirs. Furthermore, he seems to have had some prior knowledge of the form the expression of the principle should take. Actually, this was the theory's natural candidate.     

Central course of photic input in the ventral nerve cord of scorpion (Heterometrus fulvipes)

Summary The course of the photic input from the metasoma in the ventral nerve cord of scorpion was studied. The input was found to influence the activity in a large number of neurons in the nerve cord. The phenomenon of contralateral stimulation of units at various levels of the nerve cord has heen demonstrated.Acknowledgments. The electronic equipment used for the study was obtained with the help of Prof.T. H. Bullock and the late Prof.K. Pampapathi Rao who initiated me into this field of study, through a research grant from the USAFOSR to them. I am highly grateful to Prof.Bullock for permitting me to use the equipment. I am also grateful to Dr.A. R. Kasturi Bai for her kind encouragement and Dr.S. A. T. Venkatachari for his helpful comments.     

Einstein,Nordström and the early demise of scalar,Lorentz-covariant theories of gravitation

Conclusion The advent of the general theory of relativity was so entirely the work of just one person — Albert Einstein — that we cannot but wonder how long it would have taken without him for the connection between gravitation and spacetime curvature to be discovered. What would have happened if there were no Einstein? Few doubt that a theory much like special relativity would have emerged one way or another from the researchers of Lorentz, Poincaré and others. But where would the problem of relativizing gravitation have led? The saga told here shows how even the most conservative approach to relativizing gravitation theory still did lead out of Minkowski spacetime to connect gravitation to a curved spacetime. Unfortunately we still cannot know if this conclusion would have been drawn rapidly without Einstein's contribution. For what led Nordström to the gravitational field dependence of lengths and times was a very Einsteinian insistence on just the right version of the equality of inertial and gravitational mass. Unceasingly in Nordström's ear was the persistent and uncompromising voice of Einstein himself demanding that Nordström see the most distant consequences of his own theory.     

Blood pyruvate in cats after hydrocortisone hemi-succinate

Zusammenfassung Hydrocortison - Na - hemi - Succinat (100 mg des Steroids) lebenden, 4 1/2 h fastenden Katzen injiziert, ergab sofortigen Anstieg der Pyruvat-Konzentrationen im Blut mit nachfolgendem Blutzuckeranstieg.Injektionen von Kontrollösungen ergaben keine Reaktion. Nach Steroidgaben erfolgte sowohl bei normalen wie adrenolektomierten Tieren ebenfalls Anstieg.

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I should like to thank Professors SirG. Pickering andI. E. Bush and Dr.R. V. Coxon for help and Mr.B. Abraham, MissS. Briers and Mr.W. Brown for technical assistance. Glaxo Laboratories Ltd. made a generous gift of the hydrocortisone-21-phosphate.     

Interspecific protoplast fusion and complementation inaspergilli

Summary Protoplast fusion and nutritional complementation between auxotrophic mutants ofAspergillus nidulans andAspergillus fumigatus has been achieved. It is concluded that the nutritional complementation may be due to interspecific aneuploidy.The authors thank Mr.L. Manczinger and Mr.Gy. Oravecz for producing and characterizing the required mutants; Dr.D. Goldstein for providing the strainA. nidulans R. 21; Dr.D. Kerridge for the wild-type strainA. fumigatus 5085; and Mr.L. Nagy, MissÉva Sziráki and MissMária Pölös for skilful technical assistance.