Does tenotomy of skeletal muscle alter Z-line width in older animals?

Summary Results of unilateral achilles tenotomy on older (350–410 g) male rats, showed that the general width of Z-lines in the tenotomized muscles was not significantly altered by this procedure. Streaming of the Z-lines and rod formations was still present, as in younger rats.This investigation was supported in part by NIH grants 1-RO1-NS-14033 and 1-T32-07224.     

A simple procedure for removal of intra- and extra-tumoral macrophages from primary tumor cultures

Summary Improved growth of tumor cells in primary cell suspensions isolated from solid tumors can be achieved by addition of an antifungal agent, mycostatin, to the culture medium. Mycostatin inhibits the cytotoxicity of macrophages and also quickly detaches phagocytes without any apparent retardation of the growth of tumor cells. This method is particularly useful for obtaining cultures of lung tumor cells or cells from lung metastases of other tumors.This research was supported in part by grants CA-22839 and CA-28482 awarded by the National Cancer Institute, DHEW, USA. This is publication No. 406 from the Department of Basic and Clinical Immunology and Microbiology, Medical University of South Carolina.We thank Charles L. Smith for editorial assistance. Address correspondence to Y. Y., Department of Basic and Clinical Immunology and Microbiology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29403, USA.     

The serini reaction

Zusammenfassung Der Mechanismus der Serini-Reaktion wird kurz erörtert und ein 17, 20-Oxyd als Zwischenprodukt vorgeschlagen. Das stereochemische Ergebnis der Reaktion soll von zwei Faktoren abhängig sein, und zwar: 1. von der Geometrie des « transition state » und 2. von der Konfiguration des Oxydrings. Ausgehend von diesen Überlegungen, kann vorausgesagt werden, daßReichsteins Substanz 0-Diacetat durch die Serini-Reaktion in ein 17-Iso-20-keton und nicht in ein 17-Normal-20-keton umgewandelt werden soll. Tatsächlich ist das 17-Isoallopregnanol-(3)-on-20 als einziges Produkt experimentell aufgefunden worden.     

Can online search data improve the forecast accuracy of pork price in China?

Online search data provide us with a new perspective for quantifying public concern about animal diseases, which can be regarded as a major external shock to price fluctuations. We propose a modeling framework for pork price forecasting that incorporates online search data with support vector regression model. This novel framework involves three main steps: that is, formulation of the animal diseases composite indexes (ADCIs) based on online search data; forecast with the original ADCIs; and forecast improvement with the decomposed ADCIs. Considering that there are some noises within the online search data, four decomposition techniques are introduced: that is, wavelet decomposition, empirical mode decomposition, ensemble empirical mode decomposition, and singular spectrum analysis. The experimental study confirms the superiority of the proposed framework, which improves both the level and directional prediction accuracy. With the SSA method, the noise within the online search data can be removed and the performance of the optimal model is further enhanced. Owing to the long-term effect of diseases outbreak on price volatility, these improvements are more prominent in the mid- and long-term forecast horizons.     

The rate of cleavage ofβ-mercaptopyruvate by rapidly dividing cells

Zusammenfassung Quantitative Analysen des-mercaptobrenztraubensäure-spaltenden Enzyms zeigen, dass Zellen, die sich in aktivem mitotischem Prozess befinden (bzw. Krebszellen und Gewebekulturen), dieses Enzym in viel geringerem Masse enthalten als « normale » Zellen. Da dieses Enzym in dem anaeroben Stoffwechsel von Zystein eine wichtige Rolle spielt, lässt sich vermuten, dass sich der Zysteinstoffwechsel der Tumorzelle quantitativ von dem der Normalzelle unterscheidet.

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Supported by U.S. Public Health Grants H-2897, C-3211 and by a grant of the American Cancer Society (70-4612-24).     

The adequacy of thiamine in liquid diets used in animal models of alcoholism

Summary The effects of chronic administration of 2 types of liquid diets on brain thiamine pyrophosphate (TPP) levels have been investigated. With the Lieber-DeCarli diet, rats in the control group had significantly lower TPP levels compared with those of the ethanol group. The Nutrament diet used in mice was apparently adequate in the thiamine supply.Acknowledgment. The authors are thankful to Dr Hebe Greizerstein for her review and comments on this mansucript.     

The influence of chronic nicotine treatment on stress-induced gastric ulceration and emptying rate in rats.

Ten-day treatment with nicotine (5, 25 or 50 micrograms/ml drinking water) dose-dependently intensified gastric ulceration induced by cold-restraint, and emptying rate. Stomach contractions produced by graded doses of bethanechol i.v. were elevated further by nicotine treatment. It is suggested that chronic nicotine administration produces hypersensitivity of the gastric muscarinic receptors; stomach hypermotility contributes to the ulcer-worsening action of the alkaloid.     

Amino acid excretion patterns in the offspring of a ‘doubly-heterozygous’ cystine stone former

Résumé L'analyse des acides aminés de la cystinurie du type I-III dans l'urine de deux enfants d'un hétérozygote double a révélé que les quantité d'acides aminés dibasiques excrétées en 24 h sont celles qui furent trouvées chez les hétérozygotes de la cystinurie du type III. Les données expérimentales s'accordent sur ce point que les types biochimiquement hétérogènes de la cystinurie sont règiés par des allèles.