Evaluation of RGS4 as a candidate gene for schizophrenia.

Several studies have suggested that the regulator of G-protein signaling 4 (RGS4) may be a positional and functional candidate gene for schizophrenia. Three single nucleotide polymorphisms (SNP) located at the promoter region (SNP4 and SNP7) and the intron 1 (SNP18) of RGS4 have been verified in different ethnic groups. Positive results have been reported in these SNPs with different numbers of SNP combinatory haplotypes. In this study, these three SNP markers were genotyped in 218 schizophrenia pedigrees of Taiwan (864 individuals) for association analysis. Among these three SNPs, neither SNP4, SNP7, SNP18 has shown significant association with schizophrenia in single locus association analysis, nor any compositions of the three SNP haplotypes has shown significantly associations with the DSM-IV diagnosed schizophrenia. Our results fail to support the RGS4 as a candidate gene for schizophrenia when evaluated from these three SNP markers.     

Integrated medical informatics with small group teaching in medical education

National Taiwan University College of Medicine (NTUCM) introduced small groups of teaching and basic-clinical integrated courses for medical students in 1992. By using computer network and multimedia techniques, this study tried to overcome barriers to learning in small group teaching. The Department of Medical Informatics of NTUCM established campus networking and computer classrooms and provided Internet and intranet network services including mail, netnews, bulletin board systems (BBS), world wide web (WWW), gopher, ftp and local file servers. To implement an interactive learning environment, the authors first tried mail lists, newsgroups and BBS. Next an integrated learning system prototype on the WWW was developed to provide functions including online syllabus, discussion boards simulated to BBS, online talk, interactive case studies, virtual classroom with video on demand (VOD) and Internet medical resources. The results showed that after the medical students completed the required course of medical informatics and had good network access using a network to communicate with each other became a daily practice. In the future, the system will extend to the tutoring of clinical practice and continuing medical education. The authors expect a national medical education network and more international cooperation and exchange.     

Chromosome 13q neocentromeres: molecular cytogenetic characterization of three additional cases and clinical spectrum

We report three new cases of chromosome 13 derived marker chromosomes, found in unrelated patients with dysmorphisms and/or developmental delay. Molecular cytogenetic analysis was performed using fluorescence in situ hybridization (FISH) with chromosome-specific painting probes, alpha satellite probes, and physically mapped probes from chromosome 13q, as well as comparative genomic hybridization (CGH). This analysis demonstrated that these markers consisted of inversion duplications of distal portions of chromosome 13q that have separated from the endogenous chromosome 13 centromere and contain no detectable alpha satellite DNA. The presence of a functional neocentromere on these marker chromosomes was confirmed by immunofluorescence with antibodies to centromere protein-C (CENP-C). The cytogenetic location of a neocentromere in band 13q32 was confirmed by simultaneous FISH with physically mapped YACs from 13q32 and immunofluorescence with anti-CENP-C. The addition of these three new cases brings the total number of described inv dup 13q neocentic chromosomes to 11, representing 21% (11/52) of the current overall total of 52 described cases of human neocentric chromosomes. This higher than expected frequency suggests that chromosome 13q may have an increased propensity for neocentromere formation. The clinical spectrum of all 11 cases is presented, representing a unique collection of polysomy for different portions of chromosome 13q without aneuploidies for additional chromosomal regions. The complexity and variability of the phenotypes seen in these patients does not support a simple reductionist view of phenotype/genotype correlation with polysomy for certain chromosomal regions.     

Health beliefs and attitudes toward the prevention of osteoporosis in older women

OBJECTIVE: A pilot study to determine health belief factors associated with osteoporosis prevention behaviors in peri-and postmenopausal women. DESIGN: We administered a survey to a convenience sample of 60 women aged 40-95 years old in an urban family practice center and an associated retirement community. The self-reported questionnaire addressed demographics, osteoporosis risk factors, current preventive behaviors for osteoporosis, and health beliefs. RESULTS: The majority of women (89%) believed that osteoporosis is a serious condition, but only 29% perceived a personal susceptibility. Women were less concerned about osteoporosis when compared with cancer, cardiovascular disease, and neurologic disorders. Only 40% of women were taking active measures to prevent osteoporosis. There was no significant relationship between active osteoporosis prevention behaviors and five health belief factors (motivation, barrier, active participant in health care, frustration, and benefit) (p >or= 0.43). However, active behaviors to prevent osteoporosis were found to correlate with the single item "I am worried about developing osteoporosis" (p = 0.03). Most women surveyed would be willing to exercise and take calcium and a multivitamin to prevent osteoporosis. CONCLUSION: Few women are taking active measures to prevent osteoporosis despite their belief that it is a serious condition. Our data suggest that most women do not perceive a personal susceptibility to the disease. Only women who reported actively worrying about developing osteoporosis were more likely to be engaged in significant osteoporosis preventive behaviors.     

Identification of a neocentromere in a rearranged Y chromosome with no detectable DYZ3 centromeric sequence

An 18-year-old woman was evaluated because of primary amenorrhea and hypogonadism. Chromosome analysis from peripheral blood lymphocytes revealed a nonmosaic 46,X,+mar constitution. The marker was shown to be a rearranged Y chromosome consisting of an inverted duplication of the long arm: rea(Y)(qter-q11::q11-qter). Deletion mapping analysis with Y-specific STS showed that the marker lacked Yp and Y-centromeric (DYZ3) sequences, but it was positive for Yq sequences tested. Fluorescence in situ hybridization analysis with Y and X chromosome centromeric and pancentromeric probes showed no hybridization signals. The marker chromosome is present in 100% of the cells; therefore, it is mitotically stable despite the absence of DYZ3 centromeric sequence. Hybridization with CENP-A and CENP-C specific antibodies localized a neocentromere close to the breakpoint.     

Growth and maturation of cardiac myocytes in fetal sheep in the second half of gestation

Right (RVFW) and left (LVFW) ventricular free wall cardiac myocytes were collected from 25 fetal sheep aged 77-146 days gestation (term = 150 days gestation), six saline-infused catheterized fetal sheep (129 GD), and five lambs to measure gestational changes in uni- and binucleated cardiac myocyte numbers and cell volumes by confocal microscopy. At 77 days gestation, 2% of the myocytes were binucleated, which increased to 50% at 135 days gestation and 90% at 4-6 weeks after birth. RVFW uni- and binucleated myocytes were larger than those in the LVFW, and cell volumes of RVFW uni- and binucleated and LVFW binucleated myocytes (but not LVFW uninucleated myocytes) increased with gestation. Before birth, the approximate number of myocytes was greater in the LVFW than in the RVFW (P < 0.001). Before 110 GD, cardiac growth appeared to be due to myocyte hyperplasia, as approximate myocyte numbers and VFW weight increased at the same rate. After 110 days gestation, the approximate myocyte number/g VFW weight decreased, which suggests that myocyte hypertrophy, as well as hyperplasia, was occurring in association with the appearance of a greater proportion of binucleated cells after that time. By 4-6 weeks of age, there was marked hypertrophy of myocytes and an apparent reduction in myocyte number.     

Development of fungal mycelia as a skin substitute: characterization of keratinocyte proliferation and matrix metalloproteinase expression during improvement in the wound-healing process

SACCHACHITIN membranes, prepared from the waste residue of the fruiting body of Ganoderma taugae, were used in our previous study to enhance skin wound healing in animal models. In the present study, the effects of the membrane on the growth of keratinocytes and the activity of matrix metalloproteinases (MMPs), as well as on the healing of skin wounds in humans, were estimated. Fresh human foreskin was employed as the source of the keratinocyte culture, and a modified keratinocyte-SFM medium supplemented with 0.2 ng/mL of recombinant epidermal growth factor and 30 microg/mL bovine pituitary extract was used to enhance the successful growth of keratinocytes under an atmosphere of 5% CO2, at 37 degrees C. The results indicated that 0.01% SACCHACHITIN enhanced the proliferation of keratinocytes in the culture on the fourth and fifth days, and cells showed neither morphological alteration nor disordered proliferation. This evidence clearly indicated that SACCHACHITIN was not cytotoxic to and was safe for the growth of keratinocytes. Thus, SACCHACHITIN might play a positive role in the proliferation and differentiation of keratinocytes around wounds and in accelerated wound healing of epidermal tissue. In addition, microscopic observations during the growth of keratinocytes showed that normal proliferation and differentiation took place along the margin of the SACCHACHITIN membrane. This indicates that SACCHACHITIN is possibly cytocompatible with keratinocytes. Electrophoretic analysis and inhibition tests for the binding effect of SACCHACHITIN on MMPs showed that SACCHACHITIN reduced MMPs in extracellular matrix degradation and facilitated establishment of an extracellular matrix around wounds; these effects resulted in rapid wound healing. SACCHACHITIN was used as a skin dressing for patients who had skin chronicle ulcer, which had not healed for over 7 months. Preliminary clinical observations showed that the wound improved and began to heal. An analysis of MMPs by ELISA in tissue of the wound indicated a significant decrease in MMP levels.     

Rapid detection of Mycobacterium tuberculosis in various clinical specimens by using polymerase chain reaction combined with a nonradioactive hybridization system

A DNA amplification system using the polymerase chain reaction (PCR) combined with a nonradioactive digoxigenin-labeled probe hybridization was employed to detect Mycobacterium tuberculosis in clinical specimens. One hundred and thirty specimens were tested by several methods including routine culture method, acid-fast staining, BACTEC 460 detection system, PCR, and PCR-hybridization techniques. Sixteen out of 130 specimens were culture positive on Middlebrook 7H11 agar, 10 were positive with acid-fast staining, 18 were positive with BACTEC 460 detection system, 23 were positive with PCR technique, and 62 were positive with PCR-nonradioactive hybridization technique. When compared with culture results, PCR-nonradioactive hybridization had an overall sensitivity of 100% (16/16) and a specificity of 59.7% (68/114). However, 28 out of 46 (60.9%) PCR-nonradioactive hybridization positive specimens which were culture negative had clinical data supporting the diagnosis of tuberculosis. In addition, 4 specimens which were negative by routine culture but positive by BACTEC 460 detection system and two specimens which were negative by routine culture but positive by acid-fast staining were all positive by PCR-hybridization technique. These data suggest that routine culture method may not be sensitive enough to detect M. tuberculosis in all kinds of clinical specimens. Taking this deviation into account, the specificity of PCR-nonradioactive hybridization technique may be rectified range from 63% (68/108) to 79.1% (68/86). PCR itself is not satisfactory enough to detect M. tuberculosis in specimens (the sensitivity and specificity were 56.3% and 87.7%, respectively) in this study. However, when it combines with DNA hybridization technique, they can be a very powerful and rapid diagnostic tool to detect M. tuberculosis in clinical specimens.