Mate choice and mate competition influence male body size in Japanese medaka

A sexual size dimorphism usually occurs when size-dependent reproductive advantages exist in only one sex. Studies on Japanese medaka, Oryzias latipes, have demonstrated reproductive size advantages in females but not in males, even though males and females are similar in body size. We conducted mate-choice and mate-copying tests in which a female could first associate with, then mate with, either a large (>/=1 sd+X standard length) or a small male (相似文献   

Magnetic resonance images of neuronal migration anomalies

Neuronal migration anomalies are a spectrum of brain malformations caused by insults to migrating neuroblasts during the sixth week to fifth month of gestation. To study the characteristics of MRI findings in migration anomalies, MR images of 36 patients (28 children and 8 adults) with migration anomalies were evaluated. Five patients had lissencephaly, eight had pachygyria, twelve had schizencephaly, six had heterotopias of gray matter, three had hemimegalencephaly, and two had polymicrogyria. The frequency of migration anomalies was 0.51% of all cranial MRI studies and 1.21% of pediatric cranial MRI studies at our hospital. The major clinical presentations of these patients were seizure (64%), development delay (42%), motor deficits (42%) and mental retardation (25%). Twenty-five patients (69%) associated with other brain anomalies, including: other migration anomalies in 12 cases (33%), absence of the septum pellucidum in 10 cases (28%), Dandy-Walker malformation/variant in 5 cases, arachnoid cyst in 4 cases, agenesis of the corpus callosum in 3 cases, holoprosencephaly in 2 cases, mega cisterna magna in 1 case and cephalocele in 1 case. Some of them presented with multiple complicated anomalies. As MR imaging provides superb gray-white matter distinction, details of cortical anatomy and multiplanar capability, it can clearly delineate the detail morphologic changes of the brain caused by neuronal migration disorders as well as the associated anomalies.     

Effect of endurance exercise training on heart rate variability at rest in healthy young and older men

Heart rate variability (HRV) (SD of the RR interval), an index of parasympathetic tone, was measured at rest and during exercise in 13 healthy older men (age 60 to 82 years) and 11 healthy young men (age 24 to 32 years) before and after 6 months of aerobic exercise training. Before exercise training, the older subjects had a 47% lower HRV at rest compared with the young subjects (31 +/- 5 ms vs 58 +/- 4 ms, p = 0.0002). During peak exercise, the older subjects had less parasympathetic withdrawal than the young subjects (-45% vs -84%, p = 0.0001). Six months of intensive aerobic exercise training increased maximum oxygen consumption by 21% in the older group and 17% in the young group (analysis of variance: overall training effect, p = 0.0001; training effect in young vs old, p = NS). Training decreased the heart rate at rest in both the older (-9 beats/min) and the young groups (-5 beats/min, before vs after, p = 0.0001). Exercise training increased HRV at rest (p = 0.009) by 68% in the older subjects (31 +/- 5 ms to 52 +/- 8 ms) and by 17% in the young subjects (58 +/- 4 ms to 68 +/- 6 ms). Exercise training increases parasympathetic tone at rest in both the healthy older and young men, which may contribute to the reduction in mortality associated with regular exercise.     

Prevalence of harassment and discrimination among 1996 medical school graduates: a survey of eight US schools

CONTEXT: Harassing and discriminating behaviors on the part of instructors or supervisors are known to affect the quality of work performed by medical students, influence their career decisions, and have other undetermined long-term consequences. OBJECTIVE: To assess the prevalence and forms of harassment and discrimination experienced by 1996 medical school graduates. DESIGN: A self-administered survey of harassment and discrimination mailed to graduating medical students. SETTING AND PARTICIPANTS: A total of 1001 graduating medical students at 8 US medical schools (4 public and 4 private), chosen from each of the 4 regions designated by the Association of American Medical Colleges for geographic categorization. OUTCOME MEASURE: The number of reported experiences of various forms of harassment and discrimination while attending medical school. RESULTS: Of 1001 surveys, 548 (55%) were returned. Overall, 46% of the students reported experiencing some form of harassment and 41% some form of discrimination from instructors or supervisors while attending medical school. Nonsexual verbal harassment was reported by 41%; sexual verbal harassment was reported by 10%. Discrimination based on gender was reported by 29% of students; discrimination based on race was reported by 12%. CONCLUSIONS: Harassment and discrimination of medical students by instructors and supervisors continue to occur frequently, and new approaches are needed to address these problems.     

High-power potassium-titanyl-phosphate (KTP/532) laser vaporization prostatectomy: 24 hours later

All persons 65 years and older are recommended to be immunised against influenza each autumn. As immunisation rates remain low, we conducted a randomised control trial in a three-partner urban general practice to evaluate the differential effectiveness of a single postcard reminder in a general practice setting compared to usual care. All non-residential patients aged 65 years and over were identified from the age/sex/disease register. After exclusions, 325 patients were stratified by sex (125 men and 200 women) and randomised to receive either a postcard reminder in large print mailed in April or usual care. General practitioners (GPs) were blind to the randomisation. A blinded record audit performed in July demonstrated that the postcard was effective in increasing immunisation for men (chi(2)1df = 3.85; p = 0.05) but not for women (chi(2)1df = 0.45; p = 0.50). After adjusting for 1995 immunisation status, the effect of the postcard on immunisation rates was even stronger in men (Wald chi(2)1df = 6.20; p = 0.01) but remained non-significant in women (Wald chi(2)1df = 1.38; p = 0.24). With this adjustment, the odds of having the 1996 flu vaccine for men sent the postcard reminder were three times that of men in the control group (OR = 3.0; 95% CI 1.3-6.9). In a general practice setting, a single postcard reminder appears to be a promising way to boost influenza immunisation rates among ageing men. Replication of the study is recommended.     

Long-term outcome of a prospective randomized trial of conversion from cyclosporine to azathioprine treatment one year after renal transplantation

BACKGROUND: Since the introduction of cyclosporine (CsA), 1-year renal allograft survival has improved, but concern persists about the long-term adverse effects of CsA, especially with respect to renal function and blood pressure. This randomized controlled trial was set up to establish whether withdrawal of CsA would alter long-term outcome. METHODS: Adult patients who, at 1 year after renal transplantation, had a stable serum creatinine of less than 300 micromol/L and who had not had acute rejection within the last 6 months were eligible for entry. Patients were randomized either to continue on CsA (n=114) or to stop CsA and start azathioprine (Aza, n=102). All patients remained on prednisolone. Median follow-up was 93 months after transplantation (range: 52-133 months). RESULTS: There was no significant difference in actuarial 10-year patient or graft survival (Kaplan-Meier), despite an increased incidence of acute rejection within the first few months after conversion. Median serum creatinine was lower in the Aza group (Aza: 119 micromol/L; CsA. 153 micromol/L at 5 years after randomization, P=0.0002). The requirement for antihypertensive treatment was also reduced after conversion to Aza; 75% of patients required antihypertensive treatment at the start of the study, decreasing to 55% from 1 year after randomization in the Aza group and increasing to >80% in the CsA group (55% (Aza) and 84% (CsA) at 5 years after randomization, P<0.005). CONCLUSIONS: Conversion from CsA to Aza at 1 year after renal transplantation results in improvement in both blood pressure control and renal allograft function, and is not associated with significant adverse effects on long-term patient or graft survival.     

Major histocompatibility complex class I presentation of exogenous soluble tumor antigen fused to the B-fragment of Shiga toxin

Targeting exogenous antigen into the MHC class I-restricted presentation pathway is a prerequisite for the induction of cytotoxic T lymphocytes (CTL) which have been shown to represent an important component of the protective and therapeutic immune response to viral infections and tumors. In this study, we produced recombinant proteins composed of the receptor-binding non-toxic B-fragment of bacterial Shiga toxin derived from Shigella dysenteriae associated with an epitope from a model tumor antigen, Mage 1. We show that Shiga B-Mage 1 fusion proteins carrying an active or inactive endoplasmic reticulum retrieval signal (the C-terminal peptides KDEL or KDELGL, respectively) could be presented by peripheral blood mononuclear cells in an MHC class I-restricted manner to Mage 1-specific CTL. After pulsing B lymphoblastoid cells or dendritic cells with Shiga B-Mage 1 fusion protein, activation of the MHC class I-restricted Mage 1-specific CTL was also demonstrated. In further analysis, we showed that treatment with brefeldin A or paraformaldehyde fixation of Epstein-Barr virus-transformed B cells prevented the presentation of the Mage 1 T cell epitope, which excluded extracellular processing of the antigen. Immunofluorescence analysis also revealed that the Shiga B-Mage 1 fusion protein was largely excluded from Lamp-2-positive lysosomal structures. Therefore, the ability of Shiga toxin B-fragment to target dendritic cells and B cells and to direct antigen into the exogenous class I-restricted pathway makes it an attractive non-living and non-toxic vaccine vector.     

Speech perception performance in experienced cochlear-implant patients receiving the SPEAK processing strategy in the Nucleus Spectra-22 cochlear implant

Sixteen experienced cochlear implant patients with a wide range of speech-perception abilities received the SPEAK processing strategy in the Nucleus Spectra-22 cochlear implant. Speech perception was assessed in quiet and in noise with SPEAK and with the patients' previous strategies (for most, Multipeak) at the study onset, as well as after using SPEAK for 6 months. Comparisons were made within and across the two test sessions to elucidate possible learning effects. Patients were also asked to rate the strategies on seven speech recognition and sound quality scales. After 6 months' experience with SPEAK, patients showed significantly improved mean performance on a range of speech recognition measures in quiet and noise. When mean subjective ratings were compared over time there were no significant differences noted between strategies. However, many individuals rated the SPEAK strategy better for two or more of the seven subjective measures. Ratings for "appreciation of music" and "quality of my own voice" in particular were generally higher for SPEAK. Improvements were realized by patients with a wide range of speech perception abilities, including those with little or no open-set speech recognition.