DNase I hypersensitive sites far upstream of the rat tryptophan oxygenase gene direct developmentally regulated transcription in livers of transgenic mice

An experimental study on the rat sciatic nerve was performed to evaluate nerve regeneration through a collagen guide and to study the effects of alpha-melanocytic stimulating hormone (alpha-MSH) and basic fibroblast growth factor (b-FGF) in accelerating axonal elongation. After transection, nerves were repaired over a 7 mm gap using a placental collagen type IV guide. The channel was filled with either a b-FGF solution or an alpha-MSH solution or was produced with b-FGF incorporated into the guide. Four weeks later, only groups in which b-FGF had been injected or incorporated displayed a significant somatosensory evoked potential response. Histological and quantitative analysis of nerve fibres confirmed the existence of nerve continuity in groups receiving an alpha-MSH solution or a channel containing b-FGF. These results demonstrate that alpha-MSH in solution and b-FGF incorporated into a collagen type IV channel enhance peripheral nerve regeneration. However, at 4 weeks, only b-FGF (3 ng) restores functional activity.     

Spermatid-specific overexpression of the TATA-binding protein gene involves recruitment of two potent testis-specific promoters

The gene encoding the TATA-binding protein, TBP, is highly overexpressed during the haploid stages of spermatogenesis in rodents. RNase protection analyses for mRNAs containing the previously identified first, second, and eighth exons suggested that most TBP mRNAs in testis did not initiate at the first exon used in somatic cells (here designated exon 1C). Using a sensitive ligation-mediated cDNA amplification method, 5' end variants of TBP mRNA were identified, and the corresponding cDNAs were cloned from liver and testis. In liver, a single promoter/first exon is used to generate a steady-state level of roughly five molecules of TBP mRNA per diploid cell equivalent. In testis, we detect modest up-regulation of the somatic promoter and recruitment of at least five other promoters. Three of the alternative promoter/first exons, including 1C and two of the testis-specific promoter/first exons, 1D and 1E, contribute roughly equivalent amounts of mRNA which, in sum, account for greater than 90% of all TBP mRNA in testis. As a result, round spermatids contain an estimated 1000 TBP mRNA molecules per haploid cell. Testis TBP mRNA also exhibits several low abundance 5' end splicing variants; however, all detected TBP mRNA leader sequences splice onto the common exon 2 and are expected to initiate translation at the same site within exon 2. The precise locations of the three major initiation exons are mapped on the gene. The identification of the strong testis-specific promoter/first exons will be important for understanding spermatid-specific tbp gene regulation.     

Behavioral differences between two inbred strains of Fawn-Hooded rat: a model of serotonin dysfunction

The Fawn-Hooded rat (FH) strain has attracted the attention of some psychopharmacologists because of reports of its exaggerated immobility in the swim test, hypercortisolemia, excessive voluntary intake of alcohol, platelet and central serotonin abnormalities and subsensitivity to serotonergic agonists. However, there appears to be some controversy over several behavioral and physiological characteristics of these rats. The present paper proposes that the lack of reproducible findings can be traced to there being several distinct inbred strains of FH rats. Of the two compared in this communication, the FH/Wjd strain is more immobile in the forced swim test, spends more time in the open arms of the elevated plus maze, and drinks more saccharin and alcohol voluntarily than the FH/Har (Iowa Reactive) strain. Future workers are cautioned to report the source of their FH rats.     

Functional differences between the two bellies of the cricothyroid muscle

The contraction of the cricothyroid (CT) muscle, which results in a decrease in the distance between the thyroid and cricoid cartilages, is considered to be the main factor in lengthening the vocal folds. This is achieved by rotation of the CT joint. The CT muscle is composed of two distinct bellies, the pars recta and the pars obliqua. The function of each subunit is not clearly understood, although it is believed that they act differently because their fibers run in different directions. To clarify the function of the two bellies in phonation, the fundamental frequency (F0), vocal intensity, subglottic pressure, vocal fold length, and CT distance were measured using an in vivo canine laryngeal model. On the basis of these measurements, we demonstrated that the two bellies are varied in their effect on raising the pitch, rotation, and forward translation of the CT joint. The stimulation of the pars recta nerve resulted in a greater increase in the F0 value compared with that of pars obliqua. The combined activity of the pars recta and pars obliqua is important in adjustment of the vocal fold length. The CT approximations directed parallel to the pars recta and pars obliqua simultaneously were more effective in elevation of the pitch than the approximation placed parallel to the pars recta only. This finding may be clinically significant with regard to CT approximation thyroplasty in human trails.     

CFTR regions containing duodenum specific DNase I hypersensitive sites drive expression in intestinal crypt cells but not in fibroblasts

We have investigated CFTR specific intestinal expression by transfection assays in mouse cultured fibroblasts and transimmortalized intestinal crypt m-ICc12 cells using the beta-galactosidase gene linked to rat CFTR non-coding regions. Two constructs were studied, one encompassing a 5.3 kb region 5' to the gene where numerous duodenum-specific DNase I hypersensitive sites (DHSs) were previously mapped and the other including a 1.3 kb 3' region in which novel DHSs had been identified. In transient transfection assays, transgenes were expressed in m-ICc12 cells but not in fibroblasts. In m-ICc12 cells, the pattern of expression of the chromosomally integrated transgenes paralleled the endogenous expression of CFTR and beta-galactosidase activity was detected in cells containing villin and forming domes. Thus, a 6.6 kb region encompassing 5' and 3' non-coding parts of rat CFTR is able to drive specific expression of a reporter gene in cultured mouse intestinal cells having kept a crypt phenotype.     

Mutations of glucokinase gene in Japanese subjects with NIDDM

Glucokinase has been proposed to play an important role as a glucose sensor in pancreatic beta-cells. Mutations in the glucokinase gene have been shown to be the major cause of maturity-onset diabetes of the young (MODY) in Caucasian subjects. In population-association study with microsatellite DNA polymorphisms in Japanese subjects with NIDDM, a negative association was evident between NIDDM and the glucokinase gene locus, although contradictionary results were present. Using PCR-SSCP analysis, no glucokinase mutation, which induces changes in amino acid residues, was identified in Japanese subjects with classical late-onset NIDDM. These results suggest that mutations in this gene are not the major cause of common form NIDDM in Japanese.     

Identification of two Y-box binding proteins that interact with the promoters of columbid annexin I genes

The aim of this study was to investigate the role of noradrenergic descending nervous pathways in external anal sphincter motility. For this purpose, the effects of intravenously injected adrenoceptor antagonist and agonist on the tonic electrical activity of this sphincter were studied in anesthetized cats. The effects of stimulating the region of the locus coeruleus and the effects of intravenous, intracerebroventricular and intrathecal injection of the above drugs on the electromyographic responses of this muscle to pudendal nerve stimulation were also investigated. The tonic sphincteric activity and the reflex response triggered by electrically stimulating pudendal afferent nerve fibers were inhibited by alpha1-adrenoceptor antagonist nicergoline and enhanced by alpha1-adrenoceptor agonist phenylephrine. Stimulation of the locus coeruleus area either inhibited or enhanced the reflex responses. Intracerebroventricular and intrathecal injection of the alpha2-adrenoceptor agonists, morphine and leu-enkephalin decreased the amplitude of these reflex responses. All the effects of opioids were blocked by naloxone and by spinalization performed at the cervical and lumbar levels. The direct response elicited by stimulating the sphincteric motor axons was not affected either by these drugs or by the brainstem stimulation. These results suggests the existence of a pontine neuronal network controlling the motility of the external anal sphincter via noradrenergic and opioid neurons.     

Mutations in the glucokinase gene of the fetus result in reduced birth weight

Human papillomavirus (HPV) type 60 infection is histologically associated with characteristic homogeneous intracytoplasmic inclusion bodies. However, it remains unclear whether the virus is associated with cystic, pigmented or ridged plantar warts. We report a 51-year-old Japanese female with a HPV-60-induced plantar wart which showed the clinical appearance of both pigmented and ridged warts. Masson-Fontana staining revealed increased melanin granules in the epidermis of the wart. This observation suggests that HPV-60 may be associated not only with cystic warts but also with the specific morphology of ridged warts, and the biological disorder of hyperpigmentation may be controlled by additional unknown factors which differ from case to case.     

Substantive significance of significant differences between two groups.

A simple extension of discriminant analysis is described which leads to an estimate of the proportion misclassified when significant differences are used for classifying individuals into 2 groups. The estimate is obtained by a simple operation upon the t ratio in the univariate case and upon the multiple point-biserial correlation coefficient in the multivariate case. The assumptions made are those normally employed for the initial test of significance performed on the mean differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biochemical differences between rat and human cytochrome P450c17 support the different steroidogenic needs of these two species

Microsomal 17alpha-hydroxylase/17,20-lyase cytochrome P450 (P450c17) catalyzes both the 17alpha-hydroxylase reaction required to produce cortisol, the major glucocorticoid in many animals, and the 17, 20-lyase activity required for the production of androgens in all animals. In rodents such as rat, which utilize corticosterone as the major glucocorticoid, P450c17 is expressed predominantly in the gonads, and is absent in the adrenal. In other species including humans, P450c17 is expressed in both adrenal and gonads and participates in both glucocorticoid and androgen production. Rat and human forms of P450c17 are 69% identical at the amino acid level. Based on the differences in physiological roles between P450c17 in these two species, it could be predicted that major differences would be observed in their hydroxylase activities. Contrary to this hypothesis, using partially purified, recombinant human and rat P450c17, we found that the most significant differences lie in their lyase activities. Lyase activities demonstrate that the rat enzyme favors Delta4 (progesterone) substrates while the human enzyme favors Delta5 (pregnenolone) substrates. This substrate preference is also observed in the ability of steroids to decrease uncoupled H2O2 production and to increase stability during turnover. Cytochrome b5, a microsomal electron-transfer protein, enhances lyase activities of rat and human P450c17. However, the most dramatic stimulatory effect is on the human HO-PROG lyase activity. This enhancement of activities is not associated with electron transfer. These differences in biochemical properties between the two forms of P450c17 indicate that human P450c17 has evolved as an enzyme system that limits androgen production to the gonads where a favorable b5:P450c17 ratio exists. Even though orthologous forms of P450c17 are capable of catalyzing the same enzymatic activities, specific physiological requirements of each species ensure biochemical differences between these enzymes.     

Sex differences in the relationship between activity and weight loss in the rat.

Access to a running wheel combined with restricted feeding produced body weight loss at an equivalent rate in male and female litter-mate rats (Experiment 1). Thus, despite weighing less and running more, females were not more vulnerable to this procedure. When factors influencing weight loss were varied, no sex difference was found in adaptation to a new feeding schedule or in the effect of single versus group housing (Experiment 2). The apparent critical difference was that body weight loss increased running in males but not in females (Experiment 3). In all rats, rapid recovery of body weight occurred when food access was no longer restricted (Experiment 1), suggesting that "activity-based anorexia" is a misnomer for weight loss by rats in a running wheel. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex specific differences of nightmares in students

In regard of the literature reporting gender differences in dream life of adults and children the present study investigated anxiety dreams in a sample of 624 school-aged children (10 to 16 years). Girls reported a heightened frequency of anxiety dreams, especially after the age of 14 years. Gender differences in dream content were found, too. Boys more often dreamt of monsters and big animals whereas girls' dreams were dominated by humans and small animals as aggressors. Overall the findings support the hypothesis that gender specific socialization is reflected in dreams. Further research may concentrate on topics such as the relationship between anxiety dream frequency and problem-solving skills or the treatment of nightmares with imagery rehearsal.     

Shuttling of glucokinase between the nucleus and the cytoplasm in primary cultures of rat hepatocytes: possible involvement in the regulation of the glucose metabolism

Kin selection coefficients are used in two distinct ways. First, these coefficients measure phenotypic correlations that affect the marginal costs and benefits of behaviors. For example, the phenotypic correlation in sex ratio produced by two females in an isolated patch influences the favoured sex ratio. Second, kin selection coefficients describe genotypic correlations that measure fidelity of transmission. For example, a female values daughters vs. nieces according to genotypic correlations. It is widely known that kin selection coefficients may be interpreted as phenotypic or genotypic correlations in different contexts. However, these different interpretations have never been fully separated, and their different role have not been clearly explained. I provide proofs of a generic analytical approach. The technique automatically separates phenotypic correlations among social partners from genotypic components of transmission. The result is a general method that can be derived from first principles and applied to multivariate problems in social evolution. I emphasize a simple, practical maximization method that can be used to calculate equilibrium conditions for complex social interactions.     

Interaction and polymerization of the G-actin-myosin head complex: effect of DNase I

The properties of polymerization and interaction of the G-actin-myosin S1 complexes (formed with either the S1(A1) or the S1(A2) isoform) have been studied by light-scattering and fluorescence measurements in the absence and in the presence of DNase I. In the absence of DNase I, the G-actin-S1(A1) and G-actin-S1(A2) complexes were found to be characterized by different limiting concentrations (l.c.), defined as the complex concentrations above which the polymerization occurs spontaneously within 20 h at 20 degrees C in a "no salt" buffer (l.c. = 0.42 and 8.8 microM for G-actin-S1(A1) and G-actin-S1(A2), respectively). The occurrence of a limiting concentration for either complex together with the kinetic properties of the polymerization led us to conclude that the G-actin-S1 polymerization occurs via a nucleation-elongation process. Fluorescence titrations and proteolysis experiments revealed that G-actin interacts with S1 with a 1:1 stoichiometry (independently of the presence of ATP) with dissociation constants, in the absence of nucleotide, of 20 and 50 nM for the G-actin-S1(A1) and G-actin-S1(A2) complexes, respectively. In the presence of at least a 1.5-fold excess of DNase I, the polymerization of the G-actin-S1 complexes was blocked even at high protein concentration or in the presence of salts. In addition, the affinity of either S1 isoform to actin was reduced 4-5-fold by DNase I, while the stoichiometry of the G-actin-S1 complexes was not changed. However, since the dissociation constants remain in the submicromolar range, we could demonstrate the existence of ternary DNase I-G-actin-S1 complexes stable under polymerizing conditions. Finally, the study of the effect of nucleotides and of various salts on the G-actin-S1 interaction further showed significant differences between the G-actin-S1 and F-actin-S1 interactions.