Ganglion cells and topographically related nerves in the vallate papilla/von Ebner gland complex.

Ganglion cells and topographically related nerves in the vallate papilla/von Ebner gland complex were investigated in rat tongue by cytochemical, immunocytochemical, and ultrastructural methods to evaluate the possible presence of different neuronal subpopulations. Immunostaining for neurofilaments and protein gene product 9.5 revealed ganglionic cell bodies and nerve fibers. A large part of the neurons were positive at immunostaining for neuronal nitric oxide synthase (NOS), vesicular acetylcholine transporter (VAChT), or vasoactive intestinal peptide (VIP). A small subset of nerve fibers revealed immunoreactivity for cholecystokinin. Axons traveling under the lingual epithelium were evidenced by their content of calcitonin gene-related peptide (CGRP) or substance P (SP). Cell bodies positive for SP or CGRP were not detected. Using methods of co-localization, three different neuronal classes were detected. The main population was composed of AChE/NADPH-diaphorase (NADPHd)-positive cells. Small groups of acetylcholine esterase (AChE)-positive/NADPHd-negative cells were visible. Isolated neurons were AChE-negative/NADPHd-positive. The results of co-localization experiments for VAChT/NOS were consistent with those obtained by cytochemical co-localization of AChE and NADPHd. Experiments of co-localization for peptidergic and nitrergic structures revealed CGRP- and SP-immunoreactive fibers in the vallate papilla/von Ebner gland ganglion. In conclusion, the results demonstrated in the VP/VEG complex peptidergic, cholinergic, and nitrergic neurons. The presence of different neuronal subclasses suggests that a certain degree of functional specialization may exist.     

Linkage disequilibrium between GABRB3 gene and nonsyndromic familial cleft lip with or without cleft palate

The malformation of nonsyndromic cleft lip with or without cleft palate (CL/P) is a common congenital disease that affects approximately 1/1000 newborns in Caucasian populations. Genetic studies indicate that CL/P has the characteristics of a complex genetic trait. Linkage analysis and mouse-model knockout studies have suggested several candidate genes mapping in different chromosome regions for CL/P malformation. On these grounds, we have investigated, by linkage disequilibrium (LD) and parametric and nonparametric linkage analyses, five different candidate genes, including those for the beta3 subunit of the gamma-aminobutyric acid receptor (GABRB3), glutamic acid decarboxylase 1 (GAD1), retinoic acid receptor alpha (RARA), transforming growth factor beta3 (TGFB3), and msh ( Drosophila) homeobox homolog 1 (MSX1). Interestingly, a significant LD between GABRB3 and CL/P was obtained ( P-value=0.008 in the allele-wise analysis for multiallelic markers), suggesting that the GABRB3 gene is involved in this congenital disease. This new finding in humans is in agreement with previously reported data obtained with the murine model. Indeed, mouse studies indicate a role for gamma-aminobutyric acid (GABA) and its receptor in normal palate development. Exclusion of the GAD1 gene, which encodes the GABA-producing enzyme, in CL/P pathogenesis was obtained in our study. Moreover, we were unable to confirm the involvement of the MSX1 gene in nonsyndromic CL/P. Modest evidence of LD between marker alleles and CL/P was found at the RARA and TGFB3 loci suggesting a minor role for these genes in our family set of nonsyndromic CL/P.     

Application of Framingham risk estimates to ethnic minorities in United Kingdom and implications for primary prevention of heart disease in general practice: cross sectional population based study

ObjectiveTo compare the 10 year risk of coronary heart disease (CHD), stroke, and combined cardiovascular disease (CVD) estimated from the Framingham equations.DesignPopulation based cross sectional survey.SettingNine general practices in south London.Population1386 men and women, age 40-59 years, with no history of CVD (475 white people, 447 south Asian people, and 464 people of African origin), and a subgroup of 1069 without known diabetes, left ventricular hypertrophy, peripheral vascular disease, renal impairment, or target organ damage.ResultsPeople of African origin had the lowest 10 year risk estimate of CHD adjusted for age and sex (7.0%, 95% confidence interval 6.5 to 7.5) compared with white people (8.8%, 8.2 to 9.5) and south Asians (9.2%, 8.6 to 9.9) and the highest estimated risk of stroke (1.7% (1.5 to 1.9), 1.4% (1.3 to 1.6), 1.6% (1.5 to 1.8), respectively). The estimate risk of combined CVD, however, was highest in south Asians (12.5%, 11.6 to 13.4) compared with white people (11.9%, 11.0 to 12.7) and people of African origin (10.5%, 9.7 to 11.2). In the subgroup of 1069, the probability that a risk of CHD ⩾15% would identify risk of combined CVD ⩾20% was 91% in white people and 81% in both south Asians and people of African origin. The use of thresholds for risk of CHD of 12% in south Asians and 10% in people of African origin would increase the probability of identifying those at risk to 100% and 97%, respectively.ConclusionPrimary care doctors should use a lower threshold of CHD risk when treating mild uncomplicated hypertension in people of African or south Asian origin.     

Biosaccharification of cellulosic biomass in immiscible solvent–water mixtures

The enzymatic hydrolysis of wheat straw was carried out in bi-phasic media prepared with acetate esters and Na-acetate buffer. The volume percentage of the organic chemicals was 75%. The biomass was pretreated in a steam explosion plant at 217°C and for 3 min. A cellulase complex from commercial source was utilised and the experiments were run at 45°C and at constant enzyme to biomass weight ratio (0.06). Biomass loadings ranged from 6.25 to 100 g per litre of reactor. The amount of glucose formed per litre of reactor and hour and the glucose yield (grams of product per gram of biomass) were close to the values attained in pure buffer. The glucose concentration in the aqueous phase was in bi-phasic media much higher than in pure buffer and reached the value of 146 g l_H2O⁻¹ during 72 h of saccharification. The results were poorly dependent on the physical–chemical properties of the solvents. Nevertheless, butyl acetate could be slightly preferred to propyl and i-amyl acetate. The use of bi-phasic media did not require stirring rate higher than in pure buffer. The presence of acetate ester traces did not alter markedly the production of ethanol in the fermentation stage, but determined the extension of the lag phase.     

Aberrant spermatogenesis and sex determination in Bourletiellidae (Hexapoda, Collembola), and their evolutionary significance

Light and electron microscopic evidence is provided to describe a new example of a postzygotic sex-determination system in two collembolan species, Bourletiella arvalis and B. hortensis. In B. arvalis, where chromosome number could be assessed, both sexes are homogametic (n=6) and all zygotes have an identical chromosome composition (2n=12). However, male embryos develop after the loss of two sex chromosomes, making the male genotype 2n=10 (4AAX₁0X₂0). On the other hand, female embryos develop if the zygote retains all chromosomes and the female genetic system is, therefore, 4AAX₁X₁X₂X₂ (2n=12). As an apparent consequence of the lack of two chromosomes in the male germ cells, spermatogenesis is aberrant. At the first meiotic division, in fact, the two resulting secondary spermatocytes receive a different number of chromosomes: six and four. The cells which receive six chromosomes (one haploid set of four autosomes and two sex chromosomes) proceed through the meiotic process and the two spermatids generated produce two spermatozoa by a normal spermiogenesis. The cells receiving only four chromosomes do not undergo the second meiotic division and soon degenerate. The degenerating cells can be considered a morphological marker for this process, as they are easily recognizable at the electron microscope from the functional secondary spermatocytes by the appearance of the nucleus (totally condensed), the reduction of the cytoplasm (limited to a thin layer surrounding the nucleus), and the lack of most cytoplasmic organelles (with the exception of a couple of centrioles). Electron microscopic evidence has been collected for both species, allowing to extend the same process to B. hortensis, even if chromosomes could not be counted in this species. Therefore, as a result of the spermatocyte elimination, the efficiency of spermatogenesis is reduced to 50%. This process is identical to that observed in other collembolan species of the suborder Symphypleona, and it is suggested that it represents a synapomorphic feature uniting the families Dicyrtomidae, Sminthuridae and Bourletiellidae (Sminthuriformia). It is also suggested that the process is related with the finding of a distorted sex ratio in natural populations and, possibly, with the evolution of parthenogenesis. This hypothesis is supported by the fact that chromosome pairing and genetic recombination occurs only during female meiosis, while chromosomes do not pair during male meiosis. Accepted: 27 December 2000     

The activity of the plant mitochondrial inner membrane anion channel (PIMAC) of maize populations divergently selected for cold tolerance level is differentially dependent on the growth temperature of seedlings

The activity of the plant inner membrane mitochondrial anion channel (PIMAC) is involved in metabolite shuttles and mitochondrial volume changes and could have a role in plant temperature tolerance. Our objectives were to investigate (i) the occurrence and (ii) the temperature dependence of anion fluxes through PIMAC in mitochondria isolated from seedlings of three maize populations differing in terms of cold tolerance; and (iii) the relationships between the PIMAC activity kinetics and the level of cold tolerance. Populations were the source population (C0) and two populations divergently selected for high (C4H) and low (C4L) cold tolerance. Such divergently selected populations are expected to share most of their genes, with the main exception of those genes controlling cold tolerance. Arrhenius plots of PIMAC chloride fluxes showed a linear temperature dependence when seedlings were grown at 25 or 14°C, whereas a non-linear temperature dependence was found when seedlings were grown at 5°C, with or without acclimation at 14°C. The activation energy and other thermodynamic parameters of PIMAC activity varied depending on temperature treatments during seedling growth. When seedlings were grown at 14 and 5°C with acclimation, PIMAC activity of the C4H population increased, while that of C4L declined, as compared with the activities of seedlings grown at 25°C. These symmetric responses indicate that PIMAC activity changes are associated with genetically determined differences in the cold tolerance level of the investigated populations. We conclude that anion fluxes by PIMAC depend upon changes on growth temperature and are differentially related to the tolerance level of the tested populations.     

Unbalanced oxidant-antioxidant status and its effects in pediatric diseases

Oxidative stress results from a disparity between the generation of reactive oxygen species and the antioxidant ability of the organism. The alteration of the oxidant-antioxidant system brings in adults an effective state of imbalance, which may influence the pathogenesis of many diseases. Oxidative stress also plays a pivotal role in the progression of various pathologies in childhood, through a manipulation of regulatory proteins. In fact, several studies have demonstrated that an unbalanced oxidant-antioxidant status is able to determine toxic effects even during infancy. Therefore, the aim of this review was to summarize current knowledge about the dynamic relationship between oxidative stress and systemic diseases during childhood. In order to better understand these complex mechanisms, a comprehensive review of the literature was done, focusing mainly on pre-pubertal children. In fact, this age-group offers a unique opportunity to exclude confounding factors, especially those related to the metabolic effects induced by puberty. Early identification of these very young patients should be aimed at minimizing the degree of oxidative damage. Only by achieving early diagnosis, will it be possible to identify those children who could benefit from specific therapeutic approaches targeting oxidative stress.     

Plasma protein carbonylation and physical exercise

Regular physical activity is associated with a reduced risk of coronary heart disease, as it probably modifies the balance between free-radical generation and antioxidant activity. On the other hand, however, acute physical activity increases oxygen uptake and leads to a temporary imbalance between the production of reactive oxygen and nitrogen species (RONS) and their disposal: this phenomenon is called oxidative stress. Proteins are one of the most important oxidation targets during physical exercise and carbonylation is one of the most common oxidative protein modifications. In cells there is a physiological level of oxidized proteins that doesn't interfere with cell function; however, an increase in oxidized protein levels may cause a series of cellular malfunctions that could lead to a disease state. For this reason the quantification of protein oxidation is important to distinguish a healthy state from a disease state. Several studies have demonstrated an increase of carbonylated plasma proteins in athletes after exercise, but none have identified targets of this oxidation. Recently a process of protein decarbonylation has been discovered, this may indicate that carbonylation could be involved in signal transduction. The aim of our research was to characterize plasma protein carbonylation in response to physical exercise in trained male endurance athletes. We analyzed by proteomic approach their plasma proteins at resting condition and after two different kinds of physical exercise (PE). We used 2D-GE followed by western blot with specific antibodies against carbonylated proteins. The 2D analysis identified Haptoglobin as potential protein target of carbonylation after PE. We also identified Serotransferrin and Fibrinogen whose carbonylation is reduced after exercise. These methods have allowed us to obtain an overview of plasma protein oxidation after physical exercise.