A depolymerizing effect of the luteinizing hormone and follicle stimulating hormone on the neurotubules of the hypothalamus-hypophysial tract in the rat

Résumé Les neurotubules des fibres nerveuses du tract hypothalamo-hypophysaire du rat sont désorganisées après des traitments in vitro avec l'hormone lutéinisante et l'hormone folliculaire stimulante. Le méchanisme de dépolymérisation est discuté.     

A new plot to estimate protein molecular weight by density gradient ultracentrifugation

Summary A plot of the logarithm of the molecular weight against the logarithm of the sedimenting distance is proposed for estimation of protein molecular weight. The proteins are separated in acrylamide-containing linear density gradients, polymerized and stained after centrifugation.     

The structure of ceroplastodiol,a new tricyclic sesterterpene isolated from insect wax

Summary The isolation and structure elucidation of cereoplastodiol, a new tricyclic sesterterpene isolated from wax of the insectCeroplastes albolineatus are reported.Contribution No. 550 from Instituto de Química de la Universidad Nacional Autónoma de México.     

Effect of carbenoxolone on phosphodiesterase and prostaglandin synthetase activities

Summary Carbenoxolone inhibited in vitro cAMP and cGMP phosphodiesterases in a concentration-dependent and noncompetitive manner. Prostaglandin synthetase activity of rabbit kidney medulla was slightly stimulated by carbenoxolone 0.1–0.5 mM, but inhibited by higher concentrations.Acknowledgment. Supported by a grant from the Orion and Medica Scientific Foundation, Finland.     

用半导体PN结特性测定玻耳兹曼常数的一个简单装置

本文对Ｉｎｍａｎ和Ｍｉｌｌｅｒ所提出的用晶体管测定玻耳兹曼常数的装置作了一些改进，并通过对实验中误差情况的分析，提出了一个测量数据取舍的准则。从而使这个实验方法更加简单，装置更为简便，实验结果的精度进一步提高，很适合在大学物理实验中推广。     

Mendelian recessive ratios in acute poststreptococcal glomerulonephritis

Summary A prospective study of 15 families (61 siblings) of index cases of acute poststreptococcal glomerulonephritis detected a proportion of 0.260±0.016 SEM. This is an excellent fit for a single autosomal recessive trait.This study was supported by CONICIT grants SAL-S1-001 and 3126-S1-0663 (Venezuela) and Grants in Aid from CONDES (Universidad del Zulia) and Asociacion de Amigos del Riñón (Maracaibo).     

Anti-muscarinic activity of a family of C11N5 compounds isolated from Agelas sponges.

In a search for potential target sites for C11N5 compounds obtained from marine sponges of the genus Agelas we evaluated their interaction with muscarinic acetylcholine receptors from rat brain membranes. In competition experiments with 3H-QNB these compounds displayed the following rank order of potency: sceptrin greater than oroidin greater than or equal to dibromosceptrin greater than or equal to clathrodin. Sceptrin (50 microM) was shown to be a competitive inhibitor of 3H-QNB binding as revealed by Scatchard analysis. The results demonstrate the ability of these compounds to interact with multiple target molecules in the micromolar range.     

Metabolic implications in the elevation of serum activity of intestinal alkaline phosphatase in chronic renal failure

The activity of intestinal isoenzyme of serum alkaline phosphatase was evaluated in 21 non-dialyzed patients with advanced renal failure and in 52 patients on regular hemodialysis. In patients without hepatopathy, a significant inverse correlation was found between the enzyme activity and serum calcium levels. Hepatopathy was the most significant variable influencing the enzyme activity in patients on dialysis. Secondary hyperparathyroidism and a decreased rate in enzyme elimination should be assessed for the above-normal activities of intestinal ALP in serum in chronic renal failure.     

Excitability changes and muscle atrophy after de-afferentation

Zusammenfassung 1. Die Deafferenzierung der hinteren Extremität bei Ratten und Katzen verursacht eine Neigung zur Extension, welche sich 7–10 Tage nach der Operation zu entwickeln beginnt; diese sehr ausgeprägte Neigung wird durch eine erhöhte Erregbarkeit der motorischen Vorderhornzellen erklärt, welche die Extensoren innervieren.2. An der deafferenzierten Extremität atrophieren die Antigravitationsmuskeln (m. soleus und m. gastrocnemius), während man bei den Flexoren (m. extensor digitorum longus und m. tibialis anterior) kein Anzeichen von Atrophie findet.3. Die Deafferenzierungs-Atrophie der Antigravitationsmuskeln ist als eine in der Peripherie eintretende metabolische Folge des veränderten Funktionszustandes der Nervenzentren aufzufassen. Diese Ansicht konnte mit Hilfe weiterer Experimente (Reinnervation und Arbeitshypertrophie) bestätigt werden.