Exposure and toxicity of green tea polyphenols in fasted and non-fasted dogs

Standardized green tea extract was evaluated for exposure and toxicity in Beagle dogs following oral dosing by capsules. The main component (−)-epigallocatechin gallate (EGCG) accounted for 56–72% of the material. A 9-month chronic study (0, 200, 500, and 1000 mg/kg/day) was done in fasted dogs to take advantage of the reported improved catechin bioavailability with fasting. Extensive morbidity, mortality, and pathology of many major organs led to its early termination at 6.5 months and prevented identification of the toxicity mechanisms. A follow-up 13-week study examined the exposure to and toxicity of the extract. In general, toxicities were less severe than in the chronic study during the same interval. Dosing in a fed state resulted in considerably lower and less variable exposure than found under fasted conditions. Toxicity was less frequent and of lesser severity with lower exposure but limited sample size and large variability prevented reaching that definitive conclusion. Differences in mortality and morbidity between the preliminary terminated chronic and follow-up subchronic studies with the same dose of the same drug lot and similar exposure were not fully resolved as there may be other as yet unclear confounding factors.     

Role of serotonin in the development of the defensive reflex to food in the snail

9-16 days after injection of 5,7-dihydroxytryptamine which elicits degeneration of serotonergic nerve cell terminals, pairing of food and electrical shock had no effect on responses of injected animals to food, while definite food-aversive reactions were observed in control animals. In neurophysiological experiments applications of serotonin in the chamber containing the nervous system was used as a reinforcing stimulus. The amplitude of synaptic responses to nerve stimulation increased significantly in preparations in which stimulation was paired with serotonin application. In neurons involved in defensive reactions after 3-7 pairings of a drop of juice to the chemoreceptive part of the skin with serotonin application a new spike response to food has appeared. Unpaired presentations of the same stimuli were not effective. It is concluded that serotonin is an important factor in formation of conditioned adverse reactions in the snail.     

Clinical and diagnostic characteristics of the early forms of stomach cancer

Clinical and diagnostic problems of early stomach cancer were considered for 157 patients with diagnosis confirmed after operation. Gastroenterological diseases were not mentioned in the past medical history of 22.9% of the patients only. 48.4% of the patients had the so-called stomach precancerous diseases, 28.7% other diseases of the alimentary tract. At diagnosis of carcinoma, 51.6% of the patients had clinical signs of previous diseases. The importance of prophylactic medical examination in the diagnosis of early stomach cancer was emphasized (cancer was detected actively in 84.7%). Since the gross appearance of early stomach cancer looks like benign lesions, the x-ray and endoscopic methods might not be quite informative. Morphological examination of the spot biopsy material raised preoperative diagnostic accuracy up to 92.3%.     

The status of indices of immunity and hemostasis in patients with lung cancer and their changes due to general anesthesia and surgical trauma]

Phagocytosis, some factors of humoral immunity and hemostasis have been studied in cancer patients before and after surgery. Suppression of natural body resistance in the preoperative period, as well as significant inhibition of leukocyte phagocytic activity following surgery and anesthesia have been established. A correlation has been suggested between hemostasis damages in the postoperative period and an elevated IgM concentration.     

Comparative Study of Distribution of Active Sites According to Their Stereospecificity in Propylene Polymerization over the Traditional TiCl3 and Supported Titanium–Magnesium Catalysts with Different Composition

The preparative‐temperature rising elution fractionation method is used to obtain comparative data on contents of fractions with different microtacticities for polypropylene (PP) samples prepared using three catalytic systems: the traditional Ziegler–Natta (Z–N) catalyst δ‐TiCl₃ and two types of supported titanium–magnesium catalysts: the “donor‐free” TiCl₄/MgCl₂ catalyst and TiCl₄/MgCl₂·nDBP catalyst (DBP – dibutylphthalate used as an internal donor) at polymerization with the same cocatalyst (AlEt₃) in the absence and presence of an external donor (propyltrimetoxy silane). The separated individual PP fractions are also studied by gel permeation chromatography (molecular weight and molecular weight distribution) and differential scanning calorimetry. The results demonstrate general regularities and differences in the formation of active sites having different isospecificities for the traditional TiCl₃‐based Z–N catalyst and highly active supported titanium–magnesium catalysts.