The portal vein and its main affluents. An anatomic and morphometric study

There are reported the results of certain measurements made on 158 human cadavers of both sexes. A series of main parameters are given, such as the distance between the superior mesenteric vein and on the one hand its confluence with other vessels and on the other hand the pancreas and the horizontal part of the duodenum: the distance between the superior mesenteric vein together with the portal vein, and the inferior caval vein; the diameters of the portal trunk and the confluence angle between the roots of the portal vein. The results reflect the possibility to perform a troncular portocaval anastomosis in at least 90 per cent of the cases. The authors' attention was, however, directed towards the anatomy of the superior mesenteric vein, as this vessel is preferred by some surgeons in the achievement of the portocaval anastomosis.     

Identification of Shiga-like toxin in Escherichia coli strains, etiological agents of diarrheal disease

Shiga-like toxin presence, in 20 E. coli strains, etiological agents of diarrheal diseases, is studied by preparing extracts at +4 degrees C, in the presence of chloroform and by i.v. inoculation in mice. In 4 out of 20 strains, Shiga-like toxin in high titres was identified. Most of the strains presented an inconstant and variable production of Shiga-like toxin in comparison with Shigella dysenteriae type 1 (Shiga) reference strain. The authors also confirm the existence of Shiga-like toxin under 2 forms (neutralizable with Shiga antitoxic serum and non-neutralizable). The importance of the obtained results is further discussed from the point of view of pathogeny and diagnosis of the infections produced by these germs.     

Effect of exercise training on insulin sensitivity and glucose metabolism in lean, obese, and diabetic men.

To clarify the impact of vigorous physical training on in vivo insulin action and glucose metabolism independent of the intervening effects of concomitant changes in body weight and composition and residual effects of an acute exercise session, 10 lean, 10 obese, and 6 diet-controlled type II diabetic men trained for 12 wk on a cycle ergometer 4 h/wk at approximately 70% of maximal O2 uptake (VO2max) while body composition and weight were maintained by refeeding the energy expended in each training session. Before and 4-5 days after the last training session, euglycemic hyperinsulinemic (40 mU.m2.min-1) clamps were performed at a plasma glucose of 90 mg/dl, combined with indirect calorimetry. Total insulin-stimulated glucose disposal (M) was corrected for residual hepatic glucose output. Body weight, fat, and fat-free mass (FFM) did not change with training, but cardiorespiratory fitness increased by 27% in all groups. Before and after training, M was lower for the obese (5.33 +/- 0.39 mg.kg FFM-1.min-1 pretraining; 5.33 +/- 0.46 posttraining) than for the lean men (9.07 +/- 0.49 and 8.91 +/- 0.60 mg.kg FFM-1.min-1 for pretraining and posttraining, respectively) and lower for the diabetic (3.86 +/- 0.44 and 3.49 +/- 0.21) than for the obese men (P less than 0.001). Insulin sensitivity was not significantly altered by training in any group, but basal hepatic glucose production was reduced by 22% in the diabetic men. Thus, when intervening effects of the last exercise bout or body composition changes were controlled, exercise training per se leading to increased cardiorespiratory fitness had no independent impact on insulin action and did not improve the insulin resistance in obese or diabetic men.     

Extra-pair paternity and sexual dimorphism in birds

Differences in the strength of sexual selection between males and females can lead to sexual dimorphism. Extra-pair paternity (EPP) can increase the variance in male reproductive success and hence the opportunity for sexual selection. Previous research on birds suggests that EPP drives the evolution of dimorphism in plumage colour and in body size. Because EPP increases the intensity of sexual selection in males, it should lead to increased dimorphism in species with larger or more colourful males, but decreased dimorphism in species with larger or more colourful females. We explored the covariation between EPP and sexual dimorphism in wing length and plumage colouration in 401 bird species, while controlling for other, potentially confounding variables. Wing length dimorphism was associated positively with the frequency of EPP, but also with social polygamy, sex bias in parental behaviour and body size and negatively with migration distance. The frequency of EPP was the only predictor of plumage colour dimorphism. In support of our prediction, high EPP levels were associated with sexual dichromatism, positively in species in which males are more colourful and negatively in those in which females are more colourful. Contrary to our prediction, high EPP rates were associated with increased wing length dimorphism in species with both male- and female-biased dimorphism. The results support a role for EPP in the evolution of both size and plumage colour dimorphism. The two forms of dimorphism were weakly correlated and predicted by different reproductive, social and life-history traits, suggesting an independent evolution.     

Congo red binding test in enteroinvasive and nonpathogenic Escherichia coli strains.

Out of 6 variants the appropriate media to perform Congo red binding test for enteroinvasive E. coli strains were established (trypto-soy agar Eiken, T.S.A.--Cantacuzino Institute and B.T.S.D.). 12 E. coli strains belonging to enteroinvasive O-serogroups formed on Congo red agar red-coloured, non-coloured colonies or both; cultures from 59 red colonies and 61 white colonies were inoculated in guinea pig eyes. The correlation between positive Congo red binding test and positive Sereny test was 91% (out of 59 red colonies, 47 evoked keratoconjunctivitis in both infected eyes and 7 in only one eye). The negative Congo red binding test corresponds (98.4%) to the failure to induce illness in the guinea pigs' eye (only one out of 61 Crb = colonies was Sereny positive, evoking keratoconjunctivitis in only one of the two infected eyes of a guinea pig). Comparing in vivo lack of pathogenicity in 44 E. coli strains isolated from human normal intestinal flora and negative Congo red binding test, a correlation of 72.73% on B.T.S.D. and 65.91% on T.S.A. medium was found. Developing an appropriate method based on Crb test about 70% of the nonpathogenic E. coli colonies could be eliminated from the laborious agglutination with enteroinvasive O-serogroups E. coli antisera.     

Spatial association of photosynthesis and chemical defense in Arabidopsis thaliana following herbivory by Trichoplusia ni

Because they share common precursors and require significant amounts of energy, photosynthesis and defense against herbivores and pathogens may be inversely related. This relationship was examined in Arabidopsis thaliana exposed to herbivory by Trichoplusia ni neonates. The spatial pattern of photosynthesis was compared statistically with that of induction of the defense-related cinnamate-4-hydroxylase (C4H) gene across individual leaves exposed to herbivory in transgenic plants harboring a C4H:GUS gene fusion. In portions of the leaf where C4H:GUS expression was upregulated, photosynthesis was depressed, while non-photochemical quenching was increased, suggesting a trade-off between these two processes. However, photosynthetic damage spread further into surrounding areas than the induction of C4H:GUS expression. Photosynthetic depression was observed up to 1 mm from the edges of holes, whereas C4H:GUS induction typically was limited to about 0.5 mm or less from edges. Other mechanisms may be responsible for the spread of photosynthetic damage beyond where C4H-related defense was induced. Alternatively, C4H induction may reflect a subset of defensive responses more limited in their spatial distribution than the downregulation of photosynthesis. The suppression of photosynthesis in remaining leaf tissue represents a 'hidden cost' of herbivore damage.     

Mesenchymal stromal cell‐derived factors promote the colonization of collagen 3D scaffolds with human skin cells

The development of stem cell technology in combination with advances in biomaterials has opened new ways of producing engineered tissue substitutes. In this study, we investigated whether the therapeutic potential of an acellular porous scaffold made of type I collagen can be improved by the addition of a powerful trophic agent in the form of mesenchymal stromal cells conditioned medium (MSC‐CM) in order to be used as an acellular scaffold for skin wound healing treatment. Our experiments showed that MSC‐CM sustained the adherence of keratinocytes and fibroblasts as well as the proliferation of keratinocytes. Moreover, MSC‐CM had chemoattractant properties for keratinocytes and endothelial cells, attributable to the content of trophic and pro‐angiogenic factors. Also, for the dermal fibroblasts cultured on collagen scaffold in the presence of MSC‐CM versus serum control, the ratio between collagen III and I mRNAs increased by 2‐fold. Furthermore, the gene expression for α‐smooth muscle actin, tissue inhibitor of metalloproteinase‐1 and 2 and matrix metalloproteinase‐14 was significantly increased by approximately 2‐fold. In conclusion, factors existing in MSC‐CM improve the colonization of collagen 3D scaffolds, by sustaining the adherence and proliferation of keratinocytes and by inducing a pro‐healing phenotype in fibroblasts.