Effects of two devices on the surface electromyography responses of eleven shoulder muscles during Azarian in gymnastics

Difficult elements of strength such as Azarian must be presented on the rings. Specific-muscles training may be realized with 2 devices, the Herdos and the Belt, both of which reproduce the competitive situation and allow many repetitions. The purpose of this study was therefore to compare the shoulder muscle activity during the performance of Azarian with each device. Our results show that muscles rhomboid, supraspinatus, deltoid (anterior, middle, and posterior parts), biceps brachii, and triceps brachii have significant (p < 0.05) higher root mean square value when gymnasts use the Belt compared with the Herdos. Although the Herdos and the Belt reproduce competitive movement, their muscle activities are quite different. The Herdos reduces the stress on the shoulder and elbow joints, whereas the Belt induces higher muscle activity and probably provides closer muscle synergisms to the rings.     

Apolipoprotein B, apolipoprotein E, and angiotensin-converting enzyme polymorphisms in 2 Italian populations at different risk for coronary artery disease and comparison of allele frequencies among European populations

Polymorphisms at the apolipoprotein B (APOB XbaI, EcoRI, insertion-deletion), apolipoprotein E (APOE), and angiotensin-converting enzyme (ACE) loci are thought to be involved in susceptibility to coronary artery disease (CAD) and myocardial infarction. The aim of this study was to determine whether the allele distribution of the APOB, APOE, and ACE polymorphisms is different in 2 Italian regions with higher (northern Italy) and lower (Sardinia) CAD occurrence. The frequencies of the APOB and APOE alleles that are considered CAD risk factors were higher in northern Italy (APOB X- = 0.655; APOB R- = 0.198; APOB insertion = 0.757; APOE*4 = 0.110) than in Sardinia (APOB X- = 0.568; APOB R- = 0.159; APOB insertion = 0.680; APOE*4 = 0.052), although only APOE allele frequencies differed significantly (p = 0.001). ACE deletion allele frequencies in the 2 geographic areas showed an opposite pattern (northern Italy = 0.658; Sardinia = 0.721). Furthermore, we investigated the impact of APOB and APOE polymorphisms on interindividual variation in total cholesterol level in the 2 Italian samples, which differ in dietary habits. Only APOE phenotypes showed different mean levels of total cholesterol; the association was significant only in northern Italy (p = 0.04), where continental dietary habits and higher mean cholesterol levels prevail. These results support the suggestion that the cholesterol increasing effect of APOE*4 is environmentally mediated. Analysis of allele distributions among European populations, with remarkable differences in CAD prevalence, revealed a constant positive relationship between APOE*4 allele frequency and CAD incidence. The highest frequencies of APOB X- and R- were observed in Finland, where the incidence of CAD is high, and there is a partial agreement between APOB R- frequency and CAD occurrence across Europe, while APOB insertion and ACE deletion alleles are evenly distributed among European populations.     

Effects of aproteic diet on hypothalamic-pituitary- gonadal regulation in the male rat

The effect of an aproteic diet (Ap) on the reproductive axis in young male rats was studied. Also the refeeding effect at different times after the aproteic diet was studied. The Ap diet was given during 21 days. In refeeding groups, the control diet was given during 2, 4 and 6 weeks after the aproteic diet. We studied the plasmatic testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels. Also the hypothalamic GnRH concentration and in vitro hypothalamic GnRH secretion in basal and induced condition was studied. The total protein deficit produced significant reduction in body, testis, seminal vesicles and prostate weights. This was accompanied with decreased levels of plasmatic testosterone (P<0.02). In this aproteic group there was a significant reduction in LH (P<0.05) and FSH (P<0.05) plasmatic levels. Refeeding with control diet reversed this situation, producing significant increment in LH (P<0.05) and FSH levels (P<0.01) at the fourth and second weeks, respectively. The basal hypothalamic GnRH secretion did not differ from the control; nevertheless the induced secretion was significantly (P<0.05) greater in the aproteic group. Also the hypothalamic GnRH concentration was increased (P<0.05) in animals fed with the aproteic diet. The minor testis, prostate, and seminal vesicles" weight, and a decreased plasmatic testosterone in rats fed with an aproteic diet, are produced by a decrease in gonadotrophin secretion. This decrease in turn is caused by a reduction in GnRH secretion, since hypothalamic GnRH concentration is increased in rats fed with the aproteic group, and induced secretion is greater in this group. All these alterations produced by an aproteic diet are reversible, since-with contol diet refeeding-the gonadotrophin secretion returned at control levels.     

Effect of queen phenotype and social environment on early queen mortality in incipient colonies of the fire ant, Solenopsis invicta

In many ant species, including the fire ant Solenopsis invicta, queens can found their colonies alone or in associations of two or more. Colonies founded by associations produce a larger worker brood, have higher survival and mature earlier than colonies founded by solitary queens. However, cofoundresses almost invariably fight after the eclosion of the first workers. As a result, only one queen survives and monopolizes the colony's future reproductive output. Queen mortality also occurs before worker eclosion, but neither the causes (e.g. starvation, conflict), nor the factors (e.g. social environment) potentially affecting its occurrence, have been investigated. We analysed the effect of social environment and queen body mass on early mortality by keeping queens (1) solitarily, (2) within associations of four queens of the same initial mass, and (3) within associations of four queens of random initial mass. Mortality was higher for queens within associations than for solitary queens. Within associations of equally heavy queens, mortality significantly increased with the queens' body mass. In contrast, mortality of solitary queens did not significantly depend on body mass. Early mortality was significantly more frequent in associations of queens of random initial mass than in associations of equally heavy queens. Altogether these results demonstrate that queen phenotype differentially affects early queen mortality depending on the social environment, and suggest that reproductive competition rather than starvation is the main cause of mortality in multiple-queen associations. Copyright 1999 The Association for the Study of Animal Behaviour.     

Genetic variation atapolipoprotein E locus in Ethiopia: an E5 variant corresponds to two different mutant alleles: E*5 (Glu212Lys) and E*5 (Gln204Lys; Cys112Arg)

A previous investigation on apolipoprotein E polymorphism in the Ethiopian population highlighted the presence of a further variant allele named E*5 in addition to the three common alleles. The variant is considered rare elsewhere but has a frequency of more than 1% in this population. Now characterized by gene sequencing and restriction isotyping in many members of the families of the original carriers, the variant isoform has actually been found to be determined by two different gene mutations. Effectively rare in Ethiopians, one of the two, E5 (Gln204Lys, Cys 112Arg), has never been described before. The other, E5 (Glu212Lys), previously described in a subject of Turkish origin, is present at the polymorphic level only in the Ethiopian population. No subjects bearing these variants had anomalous lipid or apolipoprotein patterns. In the course of the present investigation both have been found to occur as rare variants in the southern Italian population as well. The occurrence of the two variants in the populations of Ethiopia and of the Mediterranean basin could be explained by taking into account the relevant Caucasoid contribution to the Ethiopian gene pool.     

New data on the world distribution of paraoxonase (PON1 Gln 192 --> Arg) gene frequencies

The physiological role of human paraoxonase (PON), a serum enzyme that hydrolyzes organophosphate insecticides and nerve agents, is not clear. Of the three genes in the paraoxonase gene family, PON1 shows a polymorphism, Gln 192 --> Arg, governed by two common alleles named *Q and *R. These determine two different isoforms associated, respectively, with lower and higher activity towards paraoxon, a toxic metabolic product of the insecticide parathion. The *R allele has often been found associated with an increased risk of coronary heart disease. As human populations tend towards greater exposure to environmental changes, including changes in dietary habits and contact with insecticides or other toxic substances, health risks will change as well. In studying the prevention of these newly emerging risks, it could be important to know the distribution of the two alleles in the various world populations. In this paper we report on the genotype and allele frequencies of this polymorphism in different populations, most of which have never been examined for this polymorphism. Samples were taken from mainland Italy, Sardinia, Ethiopia, Benin, and Ecuador. The *R allele frequencies for the samples were: 0.313, 0.248, 0.408, 0.612, and 0.789, respectively. The data show a large variability in allele frequencies, and, in particular, that PON1 allele distribution depends on membership to different geographic populations.     

Fos immunoreactivity in the suprachiasmatic nuclei of golden hamsters bearing an ectopic pituitary graft

Young male golden hamsters, made hyperprolactinemic by a pituitary graft under the kidney capsule, were exposed to a light pulse (1,000 lx/30 min) at Zeitgeber time (ZT) 18. Controls included hamsters receiving a sham graft (muscle). Fos immunoreactive cells were counted in both suprachiasmatic nuclei (SCN) of each animal, using an image analyzer system. The Fos immunoreactivity (Fos-ir) of the ventrolateral and dorsomedial SCN regions was greater in the pituitary-grafted hamsters. Indeed, light induced the greatest response in grafted animals in both SCN regions. However, the SCN of pituitary-grafted hamsters in the absence of light showed the lowest Fos-ir in both regions. The results support the occurrence of a dual effect of hyperprolactinemia on Fos-ir in the SCN of hamsters at ZT 18, with inhibition of Fos expression in the absence of light and potentiation of early gene expression when animals were exposed to a light pulse.