Evaluation of regioselectivity of lipases based on synthesis reaction conducted with propyl alcohol, isopropyl alcohol and propylene glycol

Preliminary investigations on the regioselectiviy of various lipases were performed. Ten commercial lipases from different origins, including three immobilized lipases, were tested by esterification reaction between caprylic acid and propyl or isopropyl alcohol in n-hexane. Reaction products were analyzed with a gas chromatograph. Best yields were obtained with immobilized lipase IM60 from Rhizomucor miehei. Therefore, this enzyme was chosen as biocatalyst for a second step of regioselectiviy study with propylene glycol which bears primary and secondary alcohol groups. It was shown, by using several solvents, that polarity could influence the product profile in situations in which multiple products of various polarities can be formed. Furthermore, the major role of silica gel in reaction mixture was established.     

Newly synthesized secretory proteins from pig pancreas are not released from a homogeneous granule compartment

The pancreatic secretion of anesthetized pigs was collected by cannulation after pulse labeling with [³H]leucine. Collection at 5 min intervals started immediately post-pulse labeling up to 85 min. The volume, the protein content and the trichloroacetic acid-precipitable radioactivity of the juice were measued. The specific radioactivity of the secertory proteins was compared to that of a zymogen granule fraction isolated from the same animal. The latter was very much higher. Caerulein stimulation for 5 min at 80 min post-pulse caused a sharp drop in the specific activity of secretory proteins in the juice, to a level lower than that of the zymogen granule content. These data support the concept of more than one pool of secretory proteins in the pancreas and are incompatible with the concept that secretory proteins derive from an homogeneous granule compartment in a functionally homogeneous population of cells. To explain our results the hypothesis of a second intracellular route for the secretory proteins is proposed.     

Orosomucoid,a New Biomarker in the Association between Obesity and Periodontitis

Epidemiological data indicate an association between periodontitis and obesity. The biological mechanisms of this relationship remain unclear. A cross-sectional study was conducted to evaluate the relationship between periodontitis and the common systemic inflammatory markers in 32 morbidly obese patients recruited in a Clinical Nutrition department. Periodontal condition was evaluated using pocket depth (PD) measurement, a classical clinical marker of ongoing periodontitis. Major periodontal risk factors were recorded (age, gender, diabetes and smoking status), as well as plasma levels of inflammatory markers (CRP, orosomucoid, IL-6) and adipokines (adiponectin, leptin). All patients included in the sample exhibited evidence of periodontitis, 16 of whom were diagnosed as having severe disease. Adjusted logistic regression analysis indicated that the severity of periodontitis was associated with the plasma level of orosomucoid (p<0.04) after adjustment for age, gender and smoking. Our study thus suggests that the severity of periodontitis, in morbidly obese patients, is associated with the increase of orosomucoid levels.     

Complexity and Demographic Explanations of Cumulative Culture

Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century) to demographic change. According to these models, cumulation of technological complexity is inhibited by decreasing— while favoured by increasing—population levels. Here we show that these findings are contingent on how complexity is defined: demography plays a much more limited role in sustaining cumulative culture in case formal models deploy Herbert Simon''s definition of complexity rather than the particular definitions of complexity hitherto assumed. Given that currently available empirical evidence doesn''t afford discriminating proper from improper definitions of complexity, our robustness analyses put into question the force of recent demographic explanations of particular episodes of cultural change.     

Beta-adrenergic influences on the firing of raphe dorsalis neurons after neonatal noradrenergic deafferentation in the rat

In Rat, neonatal lesion of the locus coeruleus induces modifications of beta-adrenergic regulations at the level of raphe dorsalis neurons. In normal conditions, the firing of serotoninergic raphe cells is not beta-adrenergic dependent. On the contrary in the lesioned animal, iontophoresis of a beta-blocking agent (DL-propranolol) produces a marked inhibition of the serotoninergic unit firing. Various mechanisms may account for this pharmacological response in the lesioned group: a classical hypersensitivity phenomenon, or the persistence of an immature regulation.     

QTL Dissection of Lag Phase in Wine Fermentation Reveals a New Translocation Responsible for Saccharomyces cerevisiae Adaptation to Sulfite

Quantitative genetics and QTL mapping are efficient strategies for deciphering the genetic polymorphisms that explain the phenotypic differences of individuals within the same species. Since a decade, this approach has been applied to eukaryotic microbes such as Saccharomyces cerevisiae in order to find natural genetic variations conferring adaptation of individuals to their environment. In this work, a QTL responsible for lag phase duration in the alcoholic fermentation of grape juice was dissected by reciprocal hemizygosity analysis. After invalidating the effect of some candidate genes, a chromosomal translocation affecting the lag phase was brought to light using de novo assembly of parental genomes. This newly described translocation (XV-t-XVI) involves the promoter region of ADH1 and the gene SSU1 and confers an increased expression of the sulfite pump during the first hours of alcoholic fermentation. This translocation constitutes another adaptation route of wine yeast to sulfites in addition to the translocation VIII-t-XVI previously described. A population survey of both translocation forms in a panel of domesticated yeast strains suggests that the translocation XV-t-XVI has been empirically selected by human activity.