Gender differences in fat patterning in children living in Ankara

Body composition is an excellent indicator for assessing obesity and nutritional status of both individuals and populations. Youth obesity has important health and social implications, because a large proportion of adult obesity has its origin in childhood. Numerous studies report that adverse levels of cardiovascular diseases risk factors are associated with adiposity in children. Concerning the Turkish population there is up to now only limited information with regard to adiposity in children. The aim of this study was therefore to determine the anthropometric and body composition characteristics and to investigate sex differences in fat patterning including fat distribution in a group of children living in Ankara. The present study evaluated the body composition of 332 boys and 269 girls aged between 8 and 11 years, attending public schools. It was carried out by a cross-sectional study and was focused on that anthropometric variables, which reflect body fat and fat-free mass. Anthropometric measurements including height, weight, triceps and subscapular skinfolds thickness were carried out on these children. The body mass index (BMI) was also calculated. The measurements were used to estimate the two-compartment model of body composition: fat-free mass (FFM) and body fat (BF) from skinfold equations. The mean fat percentage in boys is highest at 11 years (16.8%) and lowest at 10 years (15.6%). In girls these figures come to 18.2% and 17.1%, respectively. Girls of these age groups have a significantly larger percentage of body fat and skinfold thickness. At this young age there is therefore clear evidence of sexual dimorphism in fat patterning, as girls are showing a greater subcutaneous adiposity, which is mainly contributed by the triceps fat. The body fat (kg) increases in both sexes all over the investigated age groups. The Pearson correlation matrix showed a high significant relation between the anthropometric measurements (p < 0.01). The present study confirms the findings that sexual dimorphism of fat patterning in children is to be seen in the age of 8 - 11 years. It furthermore presents basic data of body composition, which could serve as reference data in other studies on the Turkish population.     

Studies in biochemical genetics in Drosophila

The metabolism of the imaginal discs of wild type, miniature, vestigial, and four-jointed varieties of Drosophila was investigated using the Cartesian diver ultramicrorespirometer. Wild type and vestigial wing disc respiration is inhibited by cyanide and azide and thus is mediated by an iron or copper porphyrin system, presumable cytochrome-cytochrome oxidase. Respiration is also inhibited by certain hydroxynaphthoquinones, believed to inactivate some enzyme between cytochromes b and c. The respiration of the vestigial and miniature wing discs is increased to normal by the addition of ascorbic acid and to a lesser extent by p-phenylenediamine and hydroquinone, hence the cytochrome oxidase and cytochrome c systems of vestigial and miniature wing discs are normal and the effects of these genes are on enzymes below cytochrome c in the respiratory chain. The respiratory enzymes of the developing imaginal discs of insects are similar to those of a wide variety of cells from bacteria to mammals. The correlation of these biochemical findings with embryological studies of the discs is discussed.     

Seasonal variation in alkalinity in pans in Central Africa

Summary The alkalinity and pH of lakes (pans) in Central Africa on Kalahari Sand, varies with the physical nature of the pan. Natural pans show a range of pH from 6.1 to 8.7, and of total alkalinity from 10 mg/l to 580 mg/l. This range is attributable to local soil differences. Some pans have been deepened or have had water pumped into them to provide drinking points for game animals. The alkalinity of pumped pans is determined by the alkalinity of the water pumped into the pan and the time during which this has taken place. All these types of pan show cyclic seasonal variation in alkalinity and pH. The range in these factors is similar from one year to the next. Animals living either in permanent (deepened or pumped) pans or in temporary (natural) pans have to withstand a wide range of alkalinity fluctuation in the course of the year.     

Pyruvate oxidation in vivo and in vitro in Dictyostelium discoideum

The in vivo rate of the reaction catalyzed by the pyruvate dehydrogenase complex in Dictyostelium discoideum was measured by exposing cells to [1-14C]alanine and relating the rate of 14CO2 evolution to the specific radioactivity of the isolated [1-14C]pyruvate. The rate obtained, 0.33 mumol/min per ml packed cell volume, was very similar to that determined by independent calculations based upon the rate of utilization of endogenous protein as an energy source in this system.     

国内双歧杆菌制剂预防小儿继发性腹泻临床疗效的Meta分析

目的系统评价国内双歧杆菌制剂临床预防小儿继发性腹泻的效果。方法按照系统评价的要求检索CBMd isc、VIP、CNK I以及万方数据库等,获得18篇符合纳入标准的文献,共计患儿4050例,对其进行M eta分析,并评价M eta分析结果的稳定性和发表偏倚。结果异质性检验χ^2=34.60,P=0.007〈0.05,采用随机效应模型进行M eta分析,合并RR=0.41,95%C I为0.35～0.49,总体效应检验,Z=10.39,P〈0.00001,差异具有非常显著性,固定效应模型RR值和95%C I与随机效应模型完全一致,剔除小样本报道后的合并RR=0.42,95%C I为0.35～0.50,与剔除前的结果基本一致,且本研究的发表偏倚得到了很好地控制。结论从现有的临床证据来看,双歧杆菌制剂能降低小儿继发性腹泻的发生率,对预防小儿继发性腹泻起到了满意的效果。     

Leptospiral antibodies in flying foxes in Australia

The sera of 271 pteropid bats (or flying foxes) collected from Queensland, New South Wales, Western Australia, and the Northern Territory were screened against a reference panel of 21 Leptospira spp. using the microscopic agglutination test (MAT). Sera were collected from December 1997 through August 1999. The MAT panel represented those serovars previously isolated in Australia, as well as exotic serovars found in neighboring countries. Leptospiral antibodies were detected in 75 (28%) of the sera and represented seven serovars, one of which, L. interrogans serovar cynopteri has been regarded as exotic to Australia. Sixty sera were reactive to one serovar, 12 sera were reactive to two serovars, and three sera were reactive to three serovars. The L. kirschneri serovar australis was most frequently identified (60.2%). The findings suggest a previously unrecognized role of pteropid bats in the natural history of leptospirosis. The potential exists for establishment of infection in new host species, the transmission of new serovars to known host species, and for changes in virulence of leptospires as a result of passage through these species.     

Chimeric heterosis in mandibular size in mice

Morphometrical observations were carried out on the mandibles of chimeras made from the embryos of C57BL/6 and BALB/c mice to compare with the two strains and their reciprocal F1 crosses. The results of the principal component analysis indicate that the first principal component (PC1) and the second principal component (PC2) extracted might be acceptable as size and shape factors, respectively. Variations of both PC1 and PC2 were generally larger in the chimeras than in the two component strains and their F1 crosses. The mean PC1 value of the chimeras was larger than that of the two component inbred strains, and it was similar to that of F1 crosses, or slightly larger. The overall size of the mandible represented by PC1 tended to be larger in the chimeras consisting of two component cells that were approximately equivalent than in those that shifted to either cell population. The above trend was observed in both sexes. These results indicate that chimeric heterosis due to the interaction between genetically different cells (C57BL/6 and BALB/c) has some relation to mandible size. The mean PC2 value, which was accepted as shape factor, was intermediate between the two inbred strains. The mandible size (PC1) and shape (PC2) were bilaterally symmetrical, except for the shape in the female chimeras and in (C57BL/6 x BALB/c)F1.     

Alterations in the heart lysosomal stability in isoproterenol induced myocardial infarction in rats

The alterations in the heart lysosomal stability following isoproterenol induced myocardial infarction were studied in albino rats. The rate of release of beta-glucuronidase at various time intervals at 37 degrees C from lysosome rich fraction was taken as a measure of lysosomal stability. As compared to the control day one, three and five samples exhibited a significant increase in beta-glucuronidase activity at all the time intervals. The subcellular distribution of beta-glucuronidase was also studied and the soluble and total activities exhibited an increase at peak infarction stage and returned to normal during the recovery. The decrease in the lysosomal stability might be attributed to the increased beta-glucuronidase activity observed following myocardial infarction.     

Decreased activity of folate transporters in lipid rafts resulted in reduced hepatic folate uptake in chronic alcoholism in rats

Folic acid is an essential nutrient that is required for one-carbon biosynthetic processes and for methylation of biomolecules. Deficiency of this micronutrient leads to disturbances in normal physiology of cell. Chronic alcoholism is well known to be associated with folate deficiency, which is due in part to folate malabsorption. The present study deals with the regulatory mechanisms of folate uptake in liver during chronic alcoholism. Male Wistar rats were fed 1 g/kg body weight/day ethanol (20 % solution) orally for 3 months, and the molecular mechanisms of folate uptake were studied in liver. The characterization of the folate transport system in liver basolateral membrane (BLM) suggested it to be a carrier mediated and acidic pH dependent, with the major involvement of proton coupled folate transporter and folate binding protein in the uptake. The folate transporters were found to be associated with lipid raft microdomain of liver BLM. Moreover, ethanol ingestion decreased the folate transport by altering the Vmax of folate transport process and downregulated the expression of folate transporters in lipid rafts. The decreased transporter levels were associated with reduced protein and mRNA levels of these transporters in liver. The deranged folate uptake together with reduced folate transporter levels in lipid rafts resulted in reduced folate levels in liver and thereby to its reduced levels in serum of ethanol-fed rats. The chronic ethanol ingestion led to decreased folate uptake in liver, which was associated with the decreased number of transporter molecules in the lipid rafts that can be ascribed to the reduced synthesis of these transporters.     

Nephrotic Syndrome in Adult Africans in Nairobi

The adult nephrotic syndrome as met with in Nairobi is predominantly encountered in young sophisticated African women, most of whom began to use skin-lightening creams containing mercury before the symptomatic onset of their illness. The particular form of mercury involved is well known to cause the nephrotic syndrome in other circumstances—for example, when applied to the skin in the treatment of psoriasis. In these circumstances the pathogenetic mechanism is thought to be of an idiosyncratic type. The use of mercury-containing skin-lightening creams in the patients studied seemed to be particularly associated with a “minimal-change” (“light-negative”) renal glomerular lesion, this lesion being present in half of the patients. The prognosis in this group of patients seems remarkably good, with 50% entering remission, 77% of these doing so spontaneously on discontinuing the use of the creams.     

Immunologic findings in healthy Haitians in Montreal

To investigate the occurrence of acquired immune deficiency syndrome in Haitians, a health status questionnaire was administered and selected studies of immune status done in a randomly chosen sample of 189 healthy adult Haitians living in Montreal. The study group was comparable to a large sample of Haitians in Montreal interviewed in the 1981 census with respect to age, sex, number of persons per household and year of immigration, but the proportion of currently married people in the study was larger (60.8% v. 42.6%). The results in the study group were compared with those in a sample of 189 non-Haitians matched for age, sex and neighbourhood of residence. Persons with known causes of impaired immune function were excluded. The participation rate was 87.5%. The study and control groups both reported few symptoms and chronic health problems and had comparable demographic data, including rate of employment and income. The mean total numbers of lymphocytes, OKT3 and OKT4 (helper) and OKT8 (suppressor) cells were significantly higher in the Haitians than in the controls, though still within normal limits. There was a borderline elevation of the lymphocyte response to phytohemagglutinin in the Haitians. The ratios of helper to suppressor T cells in the two groups were, however, not significantly different. The Haitians, in comparison with non-Haitians living in the same community, had no demonstrable abnormalities of cellular immune function.     

Dimethyl sulfoxide elicited increase in cytochrome oxidase activity in rat liver mitochondria in vivo and in vitro

A single intraperitoneal injection of dimethyl sulfoxide (275 mg/100 g body wt.) to rats stimulated cytochrome oxidase activity in liver mitochondria 2-5-fold. The enzyme activity remained at this level for as long as 5 days post-injection. There was however only 10.5% increase in the content of cytochromes a and a3 (as determined spectrophotometrically) in the same period in response to DMSO injection. The addition of either DMSO or dimethyl sulfate (a metabolite of DMSO) to isolated liver mitochondria also caused 2-3-fold increase in cytochrome oxidase activity. The results indicate that enhancement in cytochrome oxidase activity in liver mitochondria after administration of DMSO to rats is on account of activation of cytochrome oxidase caused by structural alterations in mitochondrial membranes rather than de novo synthesis of cytochrome oxidase.     

Recent achievements in in vitro culture and preservation of ovarian follicles in mammals

The mammalian ovary contains a large number of follicles that are in various developmental stages. The largest portion of them are primordial follicles. However, throughout the female reproductive lifespan only a small proportion of these follicles will produce oocytes competent to undergo successful maturation and ovulation. The rest of the ovarian oocytes (>99.9%) undergo atresia. It would be of great practical benefit to rescue some of these follicles by growing them in culture in order to provide an extra source of gametes. There is considerable interest in developing technologies that aim to produce fully-grown, developmentally competent oocytes from a pool of early developmental stages of follicles. Two methods have been used: 1/ long-term in vitro culture of either follicles or oocytes, and 2/ transplantation of ovarian tissue grafts. The development of efficient technologies may provide an additional source of oocytes for livestock production and reproduction in humans and rare or endangered species. The aim of this paper is to present a comprehensive review of recent achievements in the utilization of small ovarian follicles (primordial, preantral and early antral) by long-term in vitro culture and/or transplantation of ovarian tissue grafts (fresh and cryopreserved) in mammals including humans.     

Chromosome aberrations produced in human lymphocytes by in vivo and in vitro irradiation

The production of chromosome aberrations in vivo has been studied in lymphocytes from a patient undergoing a wholebody treatment with gamma-radiation up to a cumulative dose of 1.4 Gy. These results were compared with the observations performed on whole blood samples irradiated in vitro with doses from 0.05 up to 2 Gy of gamma-rays. The frequency of chromosome aberrations, particularly the dicentrics, was found to be similar in vivo and in vitro. The yield of dicentrics could be best related to the dose by using a linear-quadratic model in both cases, the ratio of the coefficients a/b being of 0.56 and 0.69 Gy, respectively in vivo and in vitro. These observations confirm that in vitro dose response curves may be used to evaluate accurately an in vivo absorbed dose.     

The cortical reaction in pig oocytes during in vivo and in vitro fertilization

The structure of pig oocytes after in vivo and in vitro fertilization and following treatment with the ionophore A23187 with differing levels of calcium are described, with particular reference to the cortical granules. Fertilization in vivo and in vitro resulted in cortical granule exocytosis. Sperm penetration in vivo was more rapid than in vitro and resulted in the dispersal of the cortical granules' contents in the perivitelline space following exocytosis. The contents of the granules remained adjacent to the plasmalemma after in vitro fertilization and suboolemmar vesicles were less numerous than after in vivo fertilization. High calcium levels were necessary to induce the dispersal of the cortical granule contents following treatment with ionophore. The observations are discussed regarding their relevance to the blockage to polyspermy.     

Directional cues in tactile stimuli involved in agonistic encounters in cockroaches

ABSTRACT. The ability of male cockroaches, Nauphoeta cinerea and Periplaneta americana , to respond directionally to tactile agonistic acts was tested using stimulation by artificially manipulated appendages. Responses by Nauphoeta included turning towards the stimulus at preferred angles of c. 40°, 90° and 180°, apparently relying on internally-stored directional sensory information. This turning responsiveness depended in part on the social status of the receiving individual, since subordinate individuals often retreated or failed to respond. Periplaneta males reacted to tactile stimuli by quick movements away from the stimulus or by kicking towards it. The leg used in kicking was that nearest to the part of the body which was stimulated.     

Gene-Enzyme Relationships in Histidine Biosynthesis in Bacillus subtilis

Mutants for 9 of the 10 steps in histidine biosynthesis have been isolated and identified by enzyme assay. Each locus has been mapped in relation to the aro cluster and to other histidine loci by deoxyribonucleic acid-mediated transformation. The genes which code for enzymes 3, 6, and 8 of the pathway are linked to the aro cluster. A major histidine linkage group is composed of the genes which specify enzymes 1, 2, 5, 7, and 10. The locus which codes for step 9 of the pathway is unlinked to any other identified his loci. The major histidine cluster is loosely linked to cysB and is unlinked to any of the loci concerned with aromatic amino acid biosynthesis.     

Cycloheximide genotoxicity in in vitro and in vivo test systems

The aim of this study was to investigate if there was any genotoxic effect produced by the antibiotic cycloheximide, widely used as a fungicide in agriculture as well as in everyday laboratory practice. The battery of test systems included the bacterium Salmonella typhimurium (strains TA98 and TA100), the yeast Saccharomyces cerevisiae (D7), Allium cepa somatic cells and mouse bone marrow cells. This combination of test systems enabled us to establish possible effects caused by cycloheximide at different levels of the genome and to indicate a possible mechanism of action. The results obtained in experiments showed that cycloheximide did not induce frameshift or base-pair substitution mutations in S. typhimurium regardless of metabolic activation. In S. cerevisiae cycloheximide had only toxic effects but no increase of mitotic gene conversion was noticed under the conditions of the experiment. However, in A. cepa somatic cells as well as in mouse bone marrow cells cycloheximide showed its activity causing different genetic damages, e.g., chromosome breaks, mitotic disturbances and nuclear abnormalities.     

On diffusion in organized assemblies and in biological membranes

The following paper is a brief presentation of problems related to the concepts of diffusion coefficient D and so-called viscosity eta used to characterize the cohesion of biological membranes. The first approach to this problem is a recall of the definition of D and eta in liquids. It appears that the models developed with exogenous probes to account for the diffusion-viscosity relationship are not verified in membranes. The existence of complex diffusional mechanisms, the influence of the size of the probe are presented. The results of a model calculation suggest that there is no direct correlation other than great simplifications, between the diffusion coefficient and viscosity. The calculations are then extended to actual biological assemblies and the influence of proteins on the motion of the probe considered. The limitations of the methods involving exogenous probes for determining the cohesion of biological membranes are discussed.     

Fluctuations in sugar content are not determinant in explaining variations in vitamin C in tomato fruit

The present study aimed to clarify the relationship between sugars and vitamin C in fruit. The objective was to determine whether vitamin C content was regulated by sugar content due to the role of sugar as a precursor for vitamin C. During summer, maximal content in sugar and vitamin C were found in both genotypes tested Solanum lycopersicon ‘Cervil’ and ‘Levovil’. During autumn, fruit pruning increased fruit size and hexose content but fruit vitamin C content did not increase. Therefore sugar substrate was not limiting for vitamin C synthesis during autumn. We demonstrated for two cultivars, ‘Cervil’ and ‘Levovil’, with different sugar accumulation profiles during ripening, that sugar content was not determinant in the regulation of vitamin C content. The strong correlation observed between sugars and vitamin C in ‘Cervil’ was due to their concomitant increase during fruit ripening.