Effect of egg cholesterol and dietary fats on plasma lipids, lipoproteins, and apoproteins of normal women consuming natural diets

Nine normal women, 22 to 37 years old, consumed controlled quantities of natural foods to test their responses to dietary cholesterol and saturated fat. All diets contained, as percentage of calories, 14% protein, 31% fat, and 55% carbohydrate. The main sources of polyunsaturated and saturated fats were corn oil and lard, respectively, and egg yolk was used for cholesterol supplementation. All subjects participated in four diet protocols of 15 days duration, and each diet period was separated by 3 weeks without diet control. The first diet (corn) was based on corn oil, had a polyunsaturated to saturated fat ratio (P/S) of 2.14, and contained 130 mg of cholesterol. The second diet (corn+) was identical to the first but contained a total of 875 mg of cholesterol. The third diet (lard) was based on lard, had a P/S ratio of 0.64, and contained 130 mg of cholesterol. The fourth diet (lard+) was identical to the third, but contained 875 mg of cholesterol per day. Changes of the plasma lipid, lipoprotein and apoprotein parameters relative to the corn diet were as follows: the corn+ diet significantly increased total plasma cholesterol, HDL-cholesterol, LDL-cholesterol, and apoB levels; the lard diet significantly increased total cholesterol, HDL-cholesterol, and apoB; and the lard+ diet significantly increased the total cholesterol, HDL-cholesterol, LDL-cholesterol, and apoA-I and apoB levels. There were no significant variations in VLDL-cholesterol, triglyceride, or apoE levels with these diets. The diets affected both the number of lipoprotein particles as well as the composition of LDL and HDL. Compared to the corn diet, cholesterol and saturated fat each increased the number of LDL particles by 17% and 9%, respectively, and the cholesterol per particle by 9%. The combination of saturated fat and cholesterol increased particle number by 18% and particle size by 24%. Switching from lard+ to lard, corn+, or corn diets reduced LDL-cholesterol of the group by 18%, 11%, and 28%, respectively, while a large inter-individual variability was noted. In summary, dietary fat and cholesterol affect lipid and lipoprotein levels as well as the particle number and chemical composition of both LDL and HDL. There is, however, considerable inter-individual heterogeneity in response to diet.     

Daily changes of neuropeptide Y-like immunoreactivity in the suprachiasmatic nucleus of the rat

Most of the biochemical, physiological and behavioural events in living organisms show diurnal fluctuations, normally synchronized with 24-h environmental rhythms, such as the light-dark cycle. The suprachiasmatic nucleus (SCN) of the hypothalamus is considered to be a pacemaker of the circadian rhythms in several mammals. The light-dark cycle is the primary synchronizing agent for many of the circadian rhythms which are regulated by the SCN. The photic information reaches the SCN also through a neuropeptide Y(NPY)-like immunoreactive pathway from the ventro-lateral geniculate nucleus. We found that in 12-h-dark and 12-h-light housed rats the NPY-like immunoreactive innervation of the ventro-lateral part of the SCN shows a 24 h rhythm with values rising gradually during the light phase and falling during the dark phase. Besides this rhythm, we found two peaks corresponding to the switching on and switching off of the light. The average level of NPY-like immunoreactivity, as assessed by means of semiquantitative immunocytochemistry and expressed in 'arbitrary units', is reduced in rats housed in total darkness for 2 weeks. These results confirm the physiological role of NPY in the timing of the circadian activity of the SCN.     

Unstable telocentric chromosome produced after centric misdivision of a 21q/21q translocated element

Summary An unstable telocentric chromosome was found in an individual with Down's syndrome and an unusual chromosomal mosaic, 46,XX, t(21q21q)+,21-/46,XX,21p-/45,XX,21-. As the 21q/21q chromosome was of paternal origin, based on the characteristics of its centromeric heterochromatin and on the characteristics of both 21 chromosomes of the father, it was concluded that its formation involved centric breakage and loss of centromeric material. The cell line with the 21p- chromosome may have originated from the translocation by an asymmetric misdivision of the reduced centromeric material. Of the two telocentrics produced by this fracture, one, possessing the smaller amount of centromeric apparatus, would be immediately lost; the other would be retained, but complete activity of its centromere would not be restored. It would therefore be unstable and might be lost.     

Knockout of pgdS and ggt genes improves γ‐PGA yield in B. subtilis

One of the emerging biopolymers that are currently under active investigation is bacterial poly(γ‐glutamic acid) (γ‐PGA). However, before its full industrial exploitation, a substantial increase in microbial productivity is required. γ‐PGA obtained from the Bacillus subtilis laboratory strain 168 offers the advantage of a producer characterized by a well defined genetic framework and simple manipulation techniques. In this strain, the knockout of genes for the major γ‐PGA degrading enzymes, pgdS and ggt, leads to a considerable improvement in polymer yield, which attains levels analogous to the top wild γ‐PGA producer strains. This study highlights the convenience of using the laboratory strain of B. subtilis over wild isolates in designing strain improvement strategies aimed at increasing γ‐PGA productivity. Biotechnol. Bioeng. 2013; 110: 2006–2012. © 2013 Wiley Periodicals, Inc.     

Utilisation de la spectrométrie de masse pour l’identification bactérienne: évaluation du système Axima®/Saramis®/SirWeb MALDI TOF®

Concomitant chemoradiotherapy can constitute an alternative to surgical approach in selected patients with bladder carcinoma. TNM staging, histological grading, renal and performance status represent the main prognostic factors useful to define the therapeutic strategy. Biological and genetic factors are still controversial in medical practice. The activation of oncogenes seems to characterize the initiation of superficial lowgrade tumors and the mutations in the tumor suppressor genes (TEN, TP53 and RB) appear as the most important biological features in the in situ and invasive tumors. The expression of p53, Rb, Bcl-2 has an obvious prognostic role but the published studies on molecular factors predictive of radiosensibility are heterogeneous.     

A homozygous frameshift mutation in the ESCO2 gene: evidence of intertissue and interindividual variation in Nmd efficiency

Roberts syndrome (RS) is a rare disorder characterized by tetraphocomelia and several other clinical features. Cells from RS patients exhibit characteristic premature separation of heterochromatic region of many chromosomes and abnormalities in cell cycle. Mutations in the ESCO2 gene have recently been identified in 20 RS families. We performed mutational analysis of the ESCO2 gene in two fetuses diagnosed with RS and their normal parents. In both fetuses, we identified homozygosity for the c. 745_746delGT mutation, while the non-consanguineous parents were both heterozygous for the same mutation. Considering the position of the mutation identified, we carried out qualitative and quantitative real-time ESCO2 cDNA analysis on RNA isolated from CVS-stromal cells in one fetus, amniocytes in the second fetus, and lymphocytes from the heterozygous parents. The results of this analysis showed that despite the presence of a premature termination codon (PTC) 112 nucleotides upstream of the next exon3-exon4 junction, the mutant ESCO2 mRNA was present in both fetuses, albeit at low levels, indicating a partial resistance to nonsense mediated decay (NMD). Interestingly, when cells derived from the two fetuses were treated with an inhibitor of translation, they revealed the presence of tissue and individual variability in NMD efficiency, despite the identical mutational status. The existence of such a variation in the NMD efficiency could explain the broad intrafamilial and interfamilial variability in the clinical presentation of RS patients, and in other genetic diseases where nonsense mutations are responsible for most of the mutation load. Moreover, considering that a mutated full length mRNA was produced in both fetuses, we used Western blot analysis to demonstrate the absence of the ESCO2-truncated protein in cells derived from both fetuses and in a lymphoblastoid cell line derived from the parents.     

Increased Serum Hepcidin Levels in Subjects with the Metabolic Syndrome: A Population Study

The recent discovery of hepcidin, the key iron regulatory hormone, has changed our view of iron metabolism, which in turn is long known to be linked with insulin resistant states, including type 2 diabetes mellitus and the Metabolic Syndrome (MetS). Serum ferritin levels are often elevated in MetS (Dysmetabolic hyperferritinemia - DHF), and are sometimes associated with a true mild-to-moderate hepatic iron overload (dysmetabolic iron overload syndrome - DIOS). However, the pathophysiological link between iron and MetS remains unclear. This study was aimed to investigate, for the first time, the relationship between MetS and hepcidin at population level. We measured serum hepcidin levels by Mass Spectrometry in 1,391 subjects from the Val Borbera population, and evaluated their relationship with classical MetS features. Hepcidin levels increased significantly and linearly with increasing number of MetS features, paralleling the trend of serum ferritin. In multivariate models adjusted for relevant variables including age, C-Reactive Protein, and the HFE C282Y mutation, ferritin was the only significant independent predictor of hepcidin in males, while in females MetS was also independently associated with hepcidin. Overall, these data indicate that the fundamental iron regulatory feedback is preserved in MetS, i.e. that hepcidin tends to progressively increase in response to the increase of iron stores. Due to recently discovered pleiotropic effects of hepcidin, this may worsen insulin resistance and contribute to the cardiovascular complications of MetS.     

Sex chromosome loss, micronuclei, sister chromatid exchange and aging: a study including 16 centenarians

In the present study we analysed the possible effect of age, sex and smoking on the mean values of micronucleus (MN) and sister chromatid exchange (SCE) frequencies on peripheral blood obtained from 38 subjects ranging in age from 16 to 63 years and 16 centenarians. The mean number of binucleated cells with micronuclei varied in function of age and sex (as demonstrated by the analysis of covariance (F=13.13; P<0.001), particularly evident was the increment observed in women with increasing age (interaction age/sex: F=5.53; P<0.05). Smoking habits had no effects on MN frequency (F=0.36; P>0.05). Sex (F=4.18; P<0.05) and smoking habits (F=14.64; P<0.001) influenced significantly SCE per cell frequencies, but age had no effects on them (F=2.45; P>0.05).The age-associated increase of sex chromosome loss was studied using fluorescence in situ hybridisation (FISH) on interphase nuclei.The loss of Y signals was observed in 10% of interphase cells from the centenarians males, that is six times more often than in the younger control men (1.6%). The frequency of X signal loss (1.7%) in young women was similar to that observed in male controls of the same age but the incidence of the X chromosome aneuploidy in centenarian females was appreciably higher (22%) than that found for the Y chromosome in males. These results were correlated with the data on MN formation and a positive correlation between the percentage of aneuploid cells (FISH) and MN values was observed (r=0.50; P<0.05).