[Stress fracture of athletes as a cause of groin pain]. / Stressfrakturen beim Sportler als Ursache von Leistenschmerzen.

CLINICAL/METHODICAL ISSUE: In this article, suitable imaging of stress reactions and stress fractures in athletes will be examined. STANDARD RADIOLOGICAL METHODS: Diagnostic procedures include X­ray, computed tomography (CT), magnetic resonance imaging (MRI), and bone scintigraphy. METHODICAL INNOVATIONS: MRI represents the gold standard for these types of injuries. PERFORMANCE: Of all imaging techniques, MRI shows the highest sensitivity in terms of diagnostic and prognostic aspects in stress reactions and stress fractures. PRACTICAL RECOMMENDATIONS: Early performance of MRI to evaluate the staging, therapy and prognosis of the healing process is recommended.

Early life stress accelerates behavioral and neural maturation of the hippocampus in male mice.

Early life stress (ELS) increases the risk for later cognitive and emotional dysfunction. ELS is known to truncate neural development through effects on suppressing cell birth, increasing cell death, and altering neuronal morphology, effects that have been associated with behavioral profiles indicative of precocious maturation. However, how earlier silencing of growth drives accelerated behavioral maturation has remained puzzling. Here, we test the novel hypothesis that, ELS drives a switch from growth to maturation to accelerate neural and behavioral development. To test this, we used a mouse model of ELS, fragmented maternal care, and a cross-sectional dense sampling approach focusing on hippocampus and measured effects of ELS on the ontogeny of behavioral development and biomarkers of neural maturation. Consistent with previous work, ELS was associated with an earlier developmental decline in expression of markers of cell proliferation (Ki-67) and differentiation (doublecortin). However, ELS also led to a precocious arrival of Parvalbumin-positive cells, led to an earlier switch in NMDA receptor subunit expression (marker of synaptic maturity), and was associated with an earlier rise in myelin basic protein expression (key component of the myelin sheath). In addition, in a contextual fear-conditioning task, ELS accelerated the timed developmental suppression of contextual fear. Together, these data provide support for the hypothesis that ELS serves to switch neurodevelopment from processes of growth to maturation and promotes accelerated development of some forms of emotional learning.

Stress effects on BDNF expression: effects of age, sex, and form of stress.

Stress has long been associated with the development of neuropsychiatric and neurological disorders. The effects of stress vary depending upon the age during which the stress is incurred, the duration and severity of the stressor, and can further be influenced by levels of circulating gonadal hormones. To date, the majority of research investigating the link between stress and pathology development has focused on stress hormone secretion, receptor activity, and their impact on neuronal development and functioning in developing and adult male and female rodents. In recent years, work has begun to focus on additional neuromodulatory systems that may be significantly impacted by stress that may explain changes in developmental and sex-based susceptibility to stress. New research targets include molecules that play a role in neuronal development and plasticity. Specifically, stress-induced alterations in growth factors such as neurotrophins, in particular brain-derived neurotrophic factor (BDNF), have been identified as a strong candidate modulating stress-associated pathology. Furthermore, changing expression of BDNF and its receptors over development and in response to circulating gonadal hormones extend the attractiveness of this candidate signaling pathway for understanding differences in susceptibility to stress. This review focuses on what is known with regard to the effects of stress on neurotrophin expression in rodents, and the varied effects of stress on BDNF levels as a function of developmental status and sex.

Effect of brain-derived neurotrophic factor haploinsufficiency on stress-induced remodeling of hippocampal neurons.

Chronic restraint stress (CRS) induces the remodeling (i.e., retraction and simplification) of the apical dendrites of hippocampal CA3 pyramidal neurons in rats, suggesting that intrahippocampal connectivity can be affected by a prolonged stressful challenge. Since the structural maintenance of neuronal dendritic arborizations and synaptic connectivity requires neurotrophic support, we investigated the potential role of brain derived neurotrophic factor (BDNF), a neurotrophin enriched in the hippocampus and released from neurons in an activity-dependent manner, as a mediator of the stress-induced dendritic remodeling. The analysis of Golgi-impregnated hippocampal sections revealed that wild type (WT) C57BL/6 male mice showed a similar CA3 apical dendritic remodeling in response to three weeks of CRS to that previously described for rats. Haploinsufficient BDNF mice (BDNF(±) ) did not show such remodeling, but, even without CRS, they presented shorter and simplified CA3 apical dendritic arbors, like those observed in stressed WT mice. Furthermore, unstressed BDNF(±) mice showed a significant decrease in total hippocampal volume. The dendritic arborization of CA1 pyramidal neurons was not affected by CRS or genotype. However, only in WT mice, CRS induced changes in the density of dendritic spine shape subtypes in both CA1 and CA3 apical dendrites. These results suggest a complex role of BDNF in maintaining the dendritic and spine morphology of hippocampal neurons and the associated volume of the hippocampal formation. The inability of CRS to modify the dendritic structure of CA3 pyramidal neurons in BDNF(±) mice suggests an indirect, perhaps permissive, role of BDNF in mediating hippocampal dendritic remodeling.

Risk behaviors in volunteer blood donors who seroconverted for HIV, Abidjan, Côte d'Ivoire 1997 to 2005.

BACKGROUND: The residual risk of human immunodeficiency virus (HIV) transmission from blood products in the Abidjan National Blood Transfusion Center was estimated to be 1 in 5780 blood donations over the period 2002 through 2004. We aimed at describing risk behaviors in blood donors who seroconverted for HIV in Abidjan to improve the pre-blood donation selection. STUDY DESIGN AND METHODS: We investigated the behavioral profile of HIV seroconverters assessed before their HIV diagnosis, during the blood donation selection at the blood bank of Abidjan, and compared it to the profile documented after this HIV diagnosis, at enrollment in the PRIMO-CI cohort. Since 1997, enrollment in this cohort is offered to every blood donor whose delay since HIV seroconversion was 36 months or less. RESULTS: Among the 418 blood donors who seroconverted for HIV between 1997 and 2005, 241 were enrolled in the cohort. Median age was 28 years and 63% were men. The median time between the last HIV-negative test and the first positive test was 7 months. Since the last blood donation, 29% of donors reported unprotected sexual intercourse with multiple casual sexual partners, 55% unprotected sexual intercourse with one casual sexual partner, and 36% sharing of nail clippers. During the pre-blood donation questionnaire, 69% of HIV seroconverters had reported unprotected sexual intercourse since the last blood donation (vs. 89% reported after donation), and 7% had had multiple casual sexual partners (vs. 32%). CONCLUSION: Volunteer blood donors who seroconverted for HIV in Abidjan reported a high proportion of unprotected sexual intercourse with casual sexual partners.

Brain-derived neurotrophic factor as a model system for examining gene by environment interactions across development.

There has been a dramatic rise in gene x environment studies of human behavior over the past decade that have moved the field beyond simple nature versus nurture debates. These studies offer promise in accounting for more variability in behavioral and biological phenotypes than studies that focus on genetic or experiential factors alone. They also provide clues into mechanisms of modifying genetic risk or resilience in neurodevelopmental disorders. Yet, it is rare that these studies consider how these interactions change over the course of development. In this paper, we describe research that focuses on the impact of a polymorphism in a brain-derived neurotrophic factor (BDNF) gene, known to be involved in learning and development. Specifically we present findings that assess the effects of genotypic and environmental loadings on neuroanatomic and behavioral phenotypes across development. The findings illustrate the use of a genetic mouse model that mimics the human polymorphism, to constrain the interpretation of gene-environment interactions across development in humans.

[Aetiologies of pleural effusions in HIV-infected patients in Abidjan, Côte-d'Ivoire]. / Etiologies des pleurésies chez les patients infectés par le VIH a Abidjan, Côte-d'Ivoire.

From December 1995 to March 1996 a cross sectional study was carried out in the pulmonary Medicine Unit of Treichville in Abidjan. In order to specify the main aetiologies of pleural effusion, an investigation was conducted among 35 adult patients (19 men and 16 women) suffering from pleuritis. Overall, the mean age was 32.2 years (range: 19-53 years). All the patients underwent a standard chest x-ray a skin test with 10 units of tuberculin, a whole blood cells count with CD4 T cells count and HIV test. The following analysis were performed on the pleural fluid for all patients: cytological, bacteriological and mycobacteriological examination. Some patients underwent as well a pleural biopsy performed by Abram's needle. Pleural fluid was clear in 24 cases (69%). Empyema was found in 8 cases (23%) and hemorrhagic fluid in 3 cases (9%). Tuberculosis was the dominant aetiology of pleuritis noted in 29 patients (83%), followed by far by non-tuberculous bacterial infections in 6 patients (17%). Tuberculosis associated with common bacterial infections was noted in 3 cases.

Behavioral assessments of auditory sensitivity in transgenic mice.

This report summarizes positive reinforcement conditioning procedures for assessing sensory function in transgenic mice. To illustrate these behavioral methods auditory sensitivity was measured in mice lacking alpha9 acetylcholine receptor subunits (alpha9 knock-out mice). These receptors are known to play an important role in the efferent pathways that modify cochlear responses to sound stimuli. The strategies of parameter manipulation that led these subjects through their preliminary training stages to stable threshold performances are described in detail. Techniques for estimating and interpreting sensory thresholds are discussed from the perspective of signal detection analyses. This study found no significant differences between alpha9 knock-out mice and control subjects when hearing thresholds were measured under quiet conditions, as predicted by previous behavioral and electrophysiological evidence.

Sex hormone receptor status of the dental pulp and lesions of pulpal origin.

OBJECTIVE: The purpose of this study was to determine whether the dental pulp and lesions of pulpal origin (eg, pulp polyps, periapical granulomas, and periapical cysts) exhibit receptors for the sex steroid hormones estrogen, progesterone, and androgen. STUDY DESIGN: Staining for the receptors of the hormones estrogen, progesterone, and androgen was accomplished through use of available immunohistochemical detection techniques. Pulpal tissues were obtained from freshly extracted human third molars; the other tissues were obtained from the Oral and Maxillofacial Pathology Laboratory archives. Ten samples of each tissue were processed and immunostained for these specific receptors. RESULTS: Staining for estrogen and androgen receptors was essentially negative for all cell populations examined. However, positive progesterone receptor staining of varying degrees was noted in 8 of 10 pulpal specimens. Primarily, pulpal fibroblasts and odontoblasts exhibited positive immunoreactivity. CONCLUSIONS: The results of this study suggest that although the dental pulp may be a potential target tissue for progesterone, evidence is lacking with respect to the other sex steroid hormones.

Extracellular amylase production by Saccharomycopsis capsularis and its evaluation for starch saccharification.

A strain of starch-assimilating yeast, Saccharomycopsis capsularis, isolated from Indian cereal-based fermented foods, produced significant levels of extracellular alpha-amylase and glucoamylase. The enzymes reached their peak activities during the stationary phase at the end of the 5th and 4th day of cultivation, respectively. The amylase yields were maximized by a proper choice of carbon and nitrogen sources, starting pH of the culture medium and growth temperature. High activities of the enzymes were obtained through inexpensive agricultural commodities, such as wheat bran and corn meal as carbon sources, and defatted soybean meal and peanut meal as nitrogen sources. A temperature of 28-32 degrees C and an initial pH of 4.5-5.0 were optimum. The crude amylase mixture could liquefy and saccharify a 1% starch solution completely in 24 h at 50 degrees C.

Replicability Of Factors Derived From Individual P-Technique Analyses.

Four hospitalized female schizophrenics performed self-ratings on a battery of variables for 60 consecutive days. The variables were factored, separately for each subject, and the factors were then rotated to solutions which were maximally invariant from each other. Factor matching among subjects was then assessed by congruence coefficients. The factors which replicated over persons appeared to be broad, second-order dimensions identifiable as Social Desirability, Extraversion and Anxiety. The results are discussed in relation to nomothetic vs. idiographic systems of psychology and the study of intraindividual change by P-technique as a methodology of clinical interest.

Reinforcement of competing behavior during extinction.

Conditioned behavior declines in frequency when reinforcement is discontinued. In two experiments this extinction process was facilitated when competing behavior was reinforced as the original response was extinguished. When reinforcement for competing behavior was withdrawn, however, rats resumed their original behavior and there were no overall savings in total responses to extinction.