Enhanced toxicity for mice of combinations of bacterial lipopolysaccharide and vincristine

Sublethal doses of vincristine (VNC) and bacterial lipopolysaccharide (LPS) administered simultaneously to adult male mice resulted in markedly enhanced mortality. All of 10 strains of Pseudomonas aeruginosa tested, 4 of 7 strains of Bacteroides, and 6 of 10 strains of Listeria monocytogenes were able to substitute for purified LPS in enhancing mortality in VNC-treated mice. Inoculation of mice with each of 10 strains of Pseudomonas, each of 7 strains of Bacteroides, and about half of the 10 strains of Listeria tested elicited increased resistance to the lethal action of purified LPS. The patterns of responses of mice receiving a lethal combination of 2 mg of LPS/kg and 1 mg of VNC/kg resembled those of mice receiving a lethal dose of 10 mg of VNC/kg alone or 15 mg of LPS/kg alone with respect to (i) serum glutamic pyruvate transaminase activity, (ii) hematocrit values, and (iii) thrombocytopenia. The patterns of responses of mice receiving a lethal combination of LPS and VNC resembled those of mice receiving a lethal dose of LPS alone with respect to (i) hypothermia, (ii) retention of sulfobromophthalein, (iii) fibrinogen level, (iv) prothrombin activity, (v) blood urea nitrogen levels, and (vi) time of death. These data are consistent with the proposition that the combination of VNC and LPS produces a fatal renal failure. Histological studies confirmed that there was extensive renal damage in mice treated with lethal doses of LPS alone or a lethal combination of LPS and VNC.     

Diamines and polyamines in DMBA-induced breast carcinoma containing mast cells resistant to compound 48/80

Obstetric factors were studied in an unselected series of mothers of LBW-children and compared with those in a corresponding control series. Both groups consisted of 161 women with single pregnancies and 16 with twin pregnancies. Of the 188 LBW-children, 14% were twins. Of the single infants, 42% were appropriate for gestational age (AGA), i.e. within the 10th to 90th percentile according to Swedish curves for intrauterine growth, and 58% small for gestational age (SGA). The commonest causes of low birthweight (LBW) in the AGA-group were bleeding (34%) and premature rupture of the membranes (28%). In the SGA-group toxaemia was found in 15%, but in 50% of the SGA-group no cause of LBW was demonstrable. In this latter group the average placental weight was low. The mortality was noted and 89% of the living children were examined neurologically at 5 years of age. The prognosis of the child depended on the duration of pregnancy. Bleeding during pregnancy was a prognostically unfavourable sign, but even serious bleeding complications did not exclude a normal development of the child. The prognosis was best for those infants in whom no cause of LBW was demonstrable.     

Terminal nitrogen rise

Eighteen-breath nitrogen washouts were performed on eight subjects. Each washout could be simulated by a four-compartment model, each compartment with a different ventilation-to-volume ratio and a variable contribution to expiratory flow. In large breaths initiated near residual volume, a terminal nitrogen rise (TNR) was seen. To account for the TNR with this model, there were relatively small changes in flow from compartments with markedly different nitrogen concentration. Reasons are given for believing these compartments could not be the upper and lower lung. Three of these subjects were studied in the supine, seated, and head-down positions. The TNR was seen at the same lung volume in all positions. At routine bronchospirometry in a second group of subjects, sampling with small catheters during a nitrogen washout showed a TNR in the expirate of lungs, lobes, segments, and subsegments in the upright and supine positions. Apparently a large vertical hydrostatic gradient is unnecessary to produce a TNR. Finally, the TNR was shown to occur at that lung volume where transpulmonary pressure is very small and changing rapidly with volume. This TNR was often followed by a terminal nitrogen fall while the lung was continuing to empty. The TNR occurs when flow from a large poorly ventilated compartment increases relative to the flow from other compartments. A model of lung in which the poorly ventilated compartment develops high specific compliance at low lung volume explains these data.     

Confusions in recognizing phonemes spoken by esophageal speakers: II. Vowels and diphthongs

A methodology was developed to determine the patterns of phonemic errors that listeners would make in receiving the vowels and dipthongs of monosyllables spoken by esophageal speakers. Analyses of the features preserved in the errors were performed. The identified phonemic error patterns and the features found to be poorly preserved in the errors were used to structure multiple-choice intelligibility practice materials for esophageal speakers.     

Adrenal mitochondrial and serum corticosteroid studies in rats resistant to adrenal-regeneration hypertension (ARH)

Female rats of the Wistar-Furth (W/Fu) strain appear to be resistant to the development of adrenal regeneration hypertension. At a time period, after adrenal enucleation, when Holtzman female rats had elevated serum 11-deoxycorticosterone levels and were hypertensive, none of the W/Fu rats became hypertensive. In vitro adrenal studies after quiescent kills of W/Fu rats indicated that cholesterol side chain cleavage activity was greater in mitochondria from regenerating adrenals than from controls. Both serum deoxycorticosterone and corticosterone levels were significantly greater in the adrenal-enucleated group. These studies were repeated in animals which were given a standard ether anesthetic stress. Ether stress increased cholesterol side chain cleavage activity comparably in control and adrenal-enucleated rats and also increased their serum deoxycorticosterone and corticosterone levels. Adrenal-enucleated Wistar-Furth rats had higher serum deoxycorticosterone levels than controls, whereas controls had higher serum corticosterone levels than the adrenal-enucleated group after the ether stress. These results indicate that although the adrenal-enucleated W/Fu rats have increased serum deoxycorticosterone levels, none of these rats develop frank hypertension. This suggests a resistance to deoxycorticosterone-induced hypertension in this strain of rat.     

Retinal vascular changes in congenital hypertrophy of the retinal pigment epithelium

The overlying retinal blood vessels were abnormal in five cases of congenital hypertrophy of the retinal pigment epithelium. This illustrated the well-recognized association between outer retinal degeneration and obliteration of the overlying retinal vasculature. The proposed pathophysiological mechanisms, however, seem inadequate to explain completely the morphological changes of the retinal blood vessels in the presence of atrophy of the outer retina.     

Macromolecules of the central nervous system and acoustic priming in C57BL/6Bg mice

Short-term cultures of androgen-responsive Shionogi 115 (S115) cells exhibited density-dependent regulation of proliferation rate in the presence or absence of testosterone. The average surface area per cell exposed to the growth medium was inversely proportional to population density. By contrast, long-term cultures (serially passaged in testosterone-containing medium for several months) did not exhibit density-dependent regulation of proliferation rate when grown in testosterone-containing medium. In this medium, cells became elongated and no longer exhibited any obvious decrease in exposed surface area with increasing density. Nevertheless, when subcultured into testosterone-free medium, these cells reverted to an epithelial morphology and exhibited density-dependent regulation of proliferation rate. These relationships suggested that the proliferation rate of cells decreased with density in proportion to the decrease in exposed surface area...     

Tracing enteric viruses in the European berry fruit supply chain

In recent years, numerous foodborne outbreaks due to consumption of berry fruit contaminated by human enteric viruses have been reported. This European multinational study investigated possible contamination routes by monitoring the entire food chain for a panel of human and animal enteric viruses.     

Innovations in beef production systems that enhance the nutritional and health value of beef lipids and their relationship with meat quality

Consumers are becoming more aware of the relationships between diet and health and this has increased consumer interest in the nutritional value of foods. This is impacting on the demand for foods which contain functional components that play important roles in health maintenance and disease prevention. For beef, much attention has been given to lipids. This paper reviews strategies for increasing the content of beneficial omega-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA) and reducing saturated fatty acids (SFA) in beef. Particular attention is given to intramuscular fat (IMF) and the relationships between fatty acid composition and key meat quality parameters including colour shelf life and sensory attributes. Despite the high levels of ruminal biohydrogenation of dietary PUFA, nutrition is the major route for increasing the content of beneficial fatty acids in beef. Feeding grass or concentrates containing linseed (rich in α-linolenic acid, 18:3n-3) in the diet increases the content of 18:3n-3 and its longer chain derivative eicosapentaenoic acid (EPA, 20:5n-3) in beef muscle and adipose tissue, resulting in a lower n-6:n-3 ratio. Grass feeding also increases docasahexaenoic acid (DHA, 22:6n-3). Feeding PUFA rich lipids which are protected from ruminal biohydrogenation result in further enhancement of the PUFA in meat with concomitant beneficial improvements in the ratio of polyunsaturated:saturated fatty acids (P:S ratio) and n-6:n-3 ratio. The main CLA isomer in beef is CLA cis-9, trans-11 and it is mainly associated with the triacylglycerol lipid fraction and therefore is positively correlated with level of fatness. The level of CLA cis-9, trans-11 in beef is related to (1) the amount of this isomer produced in the rumen and (2) synthesis in the tissue, by delta-9 desaturase, from ruminally produced trans vaccenic acid (18:1 trans-11; TVA). Feeding PUFA-rich diets increases the content of CLA cis-9, trans-11 in beef. Trans-fatty acids in foods are of rising importance and knowledge of the differential effects of the individual trans isomers is increasing. TVA is the major trans 18:1 isomer in beef and as the precursor for tissue CLA in both animals and man should be considered as a neutral or beneficial trans-isomer. Increasing the content of n-3 PUFA in beef can influence colour shelf life and sensory attributes of the meat. As the content of n-3 PUFA increases then sensory attributes such as "greasy" and "fishy" score higher and colour shelf life may be reduced. Under these situations, high levels of vitamin E are necessary to help stabilise the effects of incorporating high levels of long chain PUFA into meat. However, grass feeding not only increases n-3 PUFA and CLA but, due to its high content of vitamin E, colour shelf life is improved. It is evident that opportunities exist to enhance the content of health promoting fatty acids in beef and beef products offering opportunities to add value and contribute to market differentiation. However, it is imperative that these approaches to deliver "functional" attributes do not compromise on the health value (lipoperoxidation) or the taste of beef products.