Changes in lactic dehydrogenase isoenzyme pattern in muscle of tumor-bearing mice

Summary The lactic dehydrogenase isoenzyme distribution shifts gradually toward the isoenzyme pattern of the tumor in mouse muscles located distally from a transplanted mammary carcinoma.This study was supported by a grant from the Minnesota Masonic Memorial Cancer Research Fund and, in part, by Grant No. 16-P-5681015-17 from the Rehabilitation Services Administration, U.S. Dept. of Health, Education and Welfare.     

Mastoparan induces hypothermia in mice

The polypeptide mastoparan, isolated from the venom of the Oriental Hornet, Vespa orientalis, induces hypothermia in white mice 15 minutes after its intraperitoneal injection. The hypothermic effect is induced by mastoparan obtained from different hornet and wasp venoms. The normal murine core temperature is lowered by mastoparan from 38 degrees C to as far as 33 degrees C. This lowering lasts for one hour and is reversible.     

Lipid peroxidation in rabbit reticulocytes

Summary Lipid peroxides in rabbit erythrocytes and plasma were determined while anemia was induced by daily bleeding. They increased as reticulocytes increased and returned to normal with the morphological transformation to mature cells.This work was supported in part by a grant-in-aid from the Japan Medical Research Foundation and a grant-in-aid (project No. 56570363) from the Ministry of Education, Science and Culture of Japan.     

Circadian variation in urinary melatonin in clinically healthy women in Japan and the United States of America.

Urinary melatonin excretion is lower in East-Asian (Japanese) than in North-American (whites of mixed ethnic origin) women. Moreover, a statistically significant circadian rhythm is demonstrated by population-mean cosinor in the data pool from both groups of women. Furthermore, statistical significance characterizes interactions of effects from geographic differences (between ethnic groups) with temporal factors. Such spatio-temporal interactions await further scrutiny with a view inter alia of carcinogenesis as it is influenced by a spectrum of intermodulating rhythms.     

Mechanisms of flight steering in locusts

Summary Steering in flight by locusts provides a well-studied example of the modulation of a rhythmic motor output by unpredictable inputs from outside to produce adaptive behaviour, in this case a form of locomotion. The simplest form, correctional steering, allows the animal to compensate for unintentional deviations from course. Its mechanisms are relatively well understood. The central nervous circuitry which makes this behaviour possible can be thought of as an autopilot. The entire process, from sensory input to the aerodynamic effects of changed motor outputs, is here reviewed. Intentional change of course, either spontaneous or induced by a change in the outside world, is more complex: it demands not only active steering, but also the temporary disablement of the autopilot. The mechanisms by which this could be achieved are discussed.     

Glutathione peroxidase in dried blood spots

Summary A new procedure utilizing dried blood spots was developed for detecting glutathione peroxidase deficiency. Samples from a known patient with a partial defect and from rats with an induced deficiency were distinguished from respective control groups by their longer defluorescence endpoints., Samples from 100 patients with anemia and 2 phenylketonuric infants on low-protein diets contained glutathione peroxidase activity similar to that in 82 controls, when screened for the enzyme defect by the new procedure.     

Malarial parasites complete sporogony in axenic mosquitoes

Summary To obtain sporogonic stages of malaria free from microbial contaminants for in vitro studies,Anopheles stephensi were reared under sterile conditions using a mosquito cell line as larval food. The adult females, kept in sterile humidified containers and allowed to engorge on parasitemic hamsters, supported the sporogonic development of the rodent malarial parasitePlasmodium berghei. In 10 experiments, the proportion of infected mosquitoes varied from 0 to 92%, and the geometric mean number of oocysts per female mosquito from 2.5 to 58,6, with a range of 1 to 548. The average number of salivary gland sporozoites per infected mosquito was determined by direct sporozoite counts in the pooled homogenate of the thoraces of all female mosquitoes. In five experiments, it varied from 2.7×10³ to 9.0×10³. The sterile sporozoites, harvested on day 19 or 20 after the infective blood meal, were as infective for rodents as nonsterile ones.Supported in part by Public Health Service research grant AI 18345 from the National Institute of Allergy and Infectious Diseases, by a grant from the Agency of International Development DSPE-5542-G-SS-3042-00, and by a Charles and Johanna Busch award.     

Mastoparan induces hypothermia in mice

Summary The polypeptide mastoparan, isolated from the venom of the oriental Hornet,Vespa orientalis, induces hypothermia in white mice 15 minutes after its intraperitoneal injection. The hypothermic effect is induced by mastoparan obtained from different hornet and wasp venoms. The normal murine core temperature is lowered by mastoparan from 38°C to as faor as 33°C. This lowering lasts for one hour and is reversible.     

Ethanol-induced changes in plasma glucose,insulin and glucagon in fed and fasted rats

Summary Orally administered ethanol produced dose-related suppression of IRI levels and elevation of IRG levels in fed and fasting rats. Plasma glucose levels were unaffected in the fasting rats, but a moderate hyperglycemic response accompanied the decline in IRI and the rise in IRG observed in the fed rats.This research was supported in part by a grant from the National Institute on Alcohol Abuse and Alcoholism (AA-3218) and by a supplemental grant from the National Council on Alcoholism.     

Glutathione peroxidase in dried blood spots.

A new procedure utilizing dried blood spots was developed for detecting glutathione peroxidase deficiency. Samples from a known patient with a partial defect and from rats with an induced deficiency were distinguished from respective control groups by their longer defluorescence endpoints. Samples from 100 patients with anemia and 2 phenyl-ketonuric infants on low-protein diets contained glutathione peroxidase activity similar to that in 82 controls, when screened for the enzyme defect by the new procedure.     

An alkaline protease in the delayed hypersensitivity skin lesions in the guinea-pigs

Summary An alkaline hemoglobinolytic protease was extracted from the delayed hypersensitivity skin lesions induced by bovine -globulin as an antigen in the guinea-pig. The enzyme was heat-labile and inhibited by thiol-blocking reagents. The mol.wt was more than 100,000 and optimal pH around 9.We thank Prof. Hideo Hayashi and Yoshimasa Morino, Kumamoto University, for valuable discussions. This work was supported in part by grants from the Ministry of Education in Japan, the Naito Research Grant. Tokyo, and the Mitsukoshi Foundation, Tokyo.     

Qualitative novelty in seventeenth-century science: Hydrostatics from Stevin to Pascal

Two works on hydrostatics, by Simon Stevin in 1586 and by Blaise Pascal in 1654, are analysed and compared. The contrast between the two serves to highlight aspects of the qualitative novelty involved in changes within science in the first half of the seventeenth century. Stevin attempted to derive his theory from unproblematic postulates drawn from common sense but failed to achieve his goal insofar as he needed to incorporate assumptions involved in his engineering practice but not sanctioned by his postulates. Pascal's theory went beyond common sense by introducing a novel concept, pressure. Theoretical reflection on novel experiments was involved in the construction of the new concept and experiment also provided important evidence for the theory that deployed it. The new experimental reasoning was qualitatively different from the Euclidean style of reasoning adopted by Stevin. The fact that a conceptualization of a technical sense of pressure adequate for hydrostatics was far from obvious is evident from the work of those, such as Galileo and Descartes, who did not make significant moves in that direction.     

Increased blood pressure in the SHR is not related to a deficit in renomedullary PGE2

Summary Synthesis of prostaglandin E₂ by renal medulla from SHR and WKY rats was compared during early postnatal development. Although arterial blood pressure was significantly higher in SHR as early as 6 weeks of age, no difference in renal medullary prostaglandin synthesis was observed.Supported in part by a grant from the michigan Heart Association and NIH grant AM-10913.     

Superoxide dismutase activity in rabbit reticulocytes

Summary Reticulocytosis was induced in rabbits by bleeding anemia and erythrocyte superoxide dismutase activity was determined. Reticulocytes were found to contain about 1.3 times as much activity as mature erythrocytes.This work was supported in part by a Grant-in-Aid from the Japan Medical Research Foundation and a Grant-in-Aid (Project No. 56570363) from the Ministry of Education, Science and Culture of Japan.     

Possible presence of autoantibodies to zona pellucida in infertile women

Summary Of 52 serum samples from infertile women tested against isolated porcine oocytes by immunofluorescence, 8 produced intense reactions in zonae pellucidae, while only one of 52 sera from control subjects showed the reaction. Autoantibodies to the zona may be present in these women.This work was supported in part by a grant from WHO Task Force on Immunological Methods for Fertility Regulation Project No. 76464.     

The nucleolar chromosome in embryos of Rana pipiens

Summary Karyotype analyses of prometaphases from medullary plate cells derived from mid-neurulae of Rana pipiens have led to the identification of the nucleolar chromosome and nucleolar organizing region, which is located on the longer arm of a small sub-metacentric chromosome (No. 10).Supported in part by research grant GB19631X from the Natioal Science Foundation. This study constituted a portion of a dissertation submitted by G. R. N. to the Medical College of Pennsylvania in partial fulfillment of requirements for a Ph. D. degree.Supported by NDEA and subsequently NSF predoctoral traineeships.To whom reprint requests should be sent.     

Effects of pressure on oxygen consumption in cottid fish from Lake Baikal

Summary Rates of oxygen consumption in shallow dwelling cottid fish from Lake Baikal were unaffected by a change in pressure from 11 to 51 ata. The metabolic rate of deep cottids decreased by 72% when the pressure was decreased by 50% from that corresponding to habitat depth. Recovery from decreased pressures was incomplete in deep fish, suggesting that measurements of in deep dwelling fish in the literature may underestimate actual rates.Acknowledgments. Thanks are due to the US and USSR Academies of Sciences and the crew of the Titov. Support was provided by grants from The National Geographic Society, The George Baker Trust, The Max and Victoria Dreyfus Foundation, and The Griffis Foundation, Inc.     

Quantitation of proinsulin mRNA sequences in hamster insulinoma cells in culture by molecular hybridization

Summary The content of proinsulin mRNA sequences was measured in a cultured cell line established from a transplantable hamster islet cell tumor, by hybridization with proinsulin cDNA. The cells cultured in vitro were found to contain a significant amount of proinsulin mRNA sequences, compared with non-insulin-producing hamster tissues, and seem to be a useful system for the study of insulin gene expression.This work was supported in part by Grants-in-Aid Scientific Research (248129, 387065, 337013, 378052) and a Grant-in-Aid for Cancer Research (301538) from the Ministry of Education, Science and Culture, Japan.     

Transesterification of juvenile hormone occurs in vivo in locust when injected in alcoholic solvents

Catabolism of juvenile hormone was studied in vivo in the African locust by injection of the labelled natural enantiomer (10R) (12-³H) JH-III. Due to the poor solubility of JH in aqueous solution, it was injected in a water-miscible solvent. Ethanol was chosen for its apparently low toxicity towards the locust. In these experimental conditions, reverse phase liquid chromatography procedure (RP-HPLC) coupled with on line radiodetection, revealed an apolar metabolite of JH-III. This compound was found both in adult females and in fifth stadium larvae. We demonstrate that this metabolite resulted from substitution of the carboxyl methyl group of JH-III by some hydrophobic moiety. This compound co-migrates in our RP-HPLC system with the JH analog epoxy-ethyl farnesoate (JH-III ethyl ester) obtained by KCN-catalysed transesterification of JH-III in ethanol. Both JH-III ethyl ester of chemical origin and biological compounds extracted from locusts give the same spectra when analyzed by gas chromatography-mass spectroscopy (GC-MS). Transesterification of JH-III was not observed with locust tissues incubated in vitro but occurred in vivo even if JH was injected in other alcoholic solvents such as propanol. Our data suggest that transesterification of JH-III occurred in vivo and underline the role of injecting solvent in in vivo studies.