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.     

Characterization of somatic cell hybrids exhibiting extinction of AFP,Albumin and an AFP-HPRT Transgene

We utilized an AFP-HPRT transgene, i.e. the HPRT coding sequences under the regulation of AFP enhancer and promoter sequences, to localize the AFP extinguisher locus in intertypic somatic cell hybrids (hepatoma X fibroblast). This hybrid gene construct, which directly links AFP regulation to a reversibly selective gene, enabled the selection of stably transfected cells which express AFP, as well as cells showing extinction of AFP. Mouse hepatoma cells stably transfected with and expressing the transgene were fused to human fibroblasts, and the resulting somatic cell hybrids were characterized using Southern, Northern and karyotypic analyses. That several hybrids exhibited the proper extinction of AFP, AFP-HPRT and albumin suggests coregulation of these genes by an extinguisher. Segregant lines derived from these hybrids were selected for the loss of extinguisher activity and for reexpression of the transgene. Karyotypic analysis of hybrid and segregant lines, exhibiting proper AFP, albumin and AFP-HPRT phenotypes, revealed that the presence of human chromosome 7 was most closely associated with the AFP-extinguished state. The hybrids generated in these studies now make it possible to isolate the sequences responsible for AFP and albumin extinction.     

Rapid detection of beta-globin gene (HBB) mutations coupling heteroduplex and primer-extension analysis by DHPLC

Beta-thalassemia is a common inherited disease, resulting from one or more of a total of more than 200 different mutations in the beta-globin gene (HBB). Efficient and reliable mutation-screening methods are essential in order to establish appropriate prevention programs for at-risk populations based upon a molecular diagnosis. We have developed a rapid and highly-specific mutation screening test for the diagnosis of beta-thalassemia by coupling heteroduplex and primer-extension analysis based on the denaturing high performance liquid chromatography (DHPLC) system. A total of 161 healthy heterozygous Taiwanese carriers featuring 10 different HBB mutations and 30 patients exhibiting 12 different compound heterozygous or homozygous HBB mutations were subjected to DHPLC. The elution profile for the heteroduplex analysis of DHPLC could be successfully used to identify the common disease-causing mutations of HBB. To further confirm the sequence variants, we developed a technique combining multiplex primer-extension analysis coupled with DHPLC for the genotyping of eight common disease-causing mutations in the HBB gene. Overall, by coupling heteroduplex and primer-extension analysis based upon DHPLC, we were able to unambiguously identify the most-common beta-thalassemia mutations corresponding to more than 99% of HBB alleles among the Taiwanese population. In conclusion, compared to classic approaches to mutation screening for this malady, we suggest that DHPLC is an excellent technique to be applied to the genetic screening of prenatal and postnatal individuals as a part of a diagnosis program for beta-thalassemia and provides a more-efficient, economic, and sensitive means to undertake such a screening program.     

Lupus-related advanced liver involvement as the initial presentation of systemic lupus erythematosus.

BACKGROUND AND PURPOSE: Systemic lupus erythematosus (SLE), a prototype of systemic autoimmune disease characterized by multiorgan involvement with diverse clinical and serological manifestations, principally affects women in their child-bearing years. Clinically significant hepatic abnormality as the initial presentation of SLE has rarely been reported. METHODS: Eleven patients with lupus with initial presentation of lupus-related hepatitis were included in this retrospective review. Clinical manifestation, immunological profiles, and risk factors for poor prognosis were analyzed. RESULTS: The most commonly associated clinical manifestations were found to be thrombocytopenia, leukopenia, advancing age, and presence of anti-SSA/Ro antibody and anti-thyroid antibodies. The diagnosis of SLE was delayed due to dominant hepatic abnormalities. Age greater than 50 years and marked hepatic decompensation in accordance with Child classification B and C might suggest poor prognosis (p=0.06). However, the p value was not statistically significant because of the small sample size. CONCLUSIONS: Lupus-related hepatitis, particularly in late-onset lupus, is common. In addition, the presence of anti-SSA, anti-thyroglobulin, and anti-microsomal antibodies is indicative of hepatic involvement in patients with SLE.     

四川参叶的生药学鉴定研究

参叶为少常用中药,主产于四川。我们通过调查,发現四川药用的参叶共有8种,均属人参属植物。本文报道了对8种参叶的生药学鉴定研究结果,提出了它们之间性状、显微特征的异同,创设了表皮细胞数的概念,并肯定了它在生药鉴定中的价值。研究结果对于合理用药、开发利用人参属植物资源及人参属植物的分类均有一定的价值。     

Differential expression and regulation of p53 in human prostatic cells

Although genetic analysis has convincingly shown the association possibly existing between alterations in p53 tumor suppressor gene and a broad spectrum of human tumors including prostate cancer, surprisingly little is known about ways in which p53 at the protein level is controlled. To determine factors that may play a role in its regulation and expression, changes in p53 protein was investigated by using the androgen-insensitive JCA-1, DU-145, PC-3 and the androgen-responsive LNCaP cells. With the exception of PC-3 cells in which p53 is missing, multiple distinct forms of p53 were found in the other 3 prostate cell lines. A single p53 band was detected in the JCA-1 cell extracts, whereas two and three p53 immunoreactive bands were correspondingly observed in the DU-145 and LNCaP cells. The relative abundance and distribution of the different forms of p53 in the latter two cell types varied with proliferation of cells in culture. In the presence of charcoal-stripped fetal bovine serum (cFBS), LNCaP took on the morphology of neuroendocrine cells, a phenotypic change which was accompanied by a greater than 80% reduction in p53 expression, concurrent with elimination of the two slow migrating forms of p53. Induction of apoptosis in JCA-1 cells by treatment with the retinoid 4-HPR caused the virtual disappearance of p53, which coincided with specific processing of p53 into lower molecular weight 28 kD fragments. We propose that rapid and dynamic posttranslational changes in p53 may actively participate in determining mutually exclusive functional cellular events such as proliferation, differentiation, and apoptosis.     

Increasing nosocomial infections of methicillin-resistant Staphylococcus aureus at a teaching hospital in Taiwan

Methicillin-resistant Staphylococcus aureus (MRSA) is a worldwide important pathogen in nosocomial infections. To investigate the extent of the problem in Taiwan, analysis for the period of 1981-1994 was carried out of prospective surveillance data from the National Taiwan University Hospital, a major university teaching hospital in Taiwan. The number of nosocomial MRSA infections increased from five in 1981 to 133 in 1994, and the incidence increased from 0.2 episodes/1000 discharges in 1981 to 2.9 episodes/1000 discharges in 1994. The most common infection site was surgical wounds, which accounted for 26.3% of total 577 episodes of nosocomial MRSA infections during the study period. However, bacteraemia has become more and more common during the past 14 years. MRSA infections occured more frequently in patients stayed in the burn unit and other intensive care units than in the general wards. Other than oxacillin, the resistance rate to many other antibiotics also increased in S. aureus strains causing nosocomial infections in this hospital. Vancomycin remained active to all these S. aureus strains, even until 1994.     

Marital role attitudes and expected role behaviors of college youth in mainland China and Taiwan

Mainland China and Taiwan have been politically and physically segregated since 1949, and it was not until the late 1980s that limited contacts and cultural exchanges between the two societies began to take place. During their period of segregation, the two societies adopted different approaches toward gender roles. While gender equality was actively promoted in mainland China, the government in Taiwan lacked the theoretical guidance on how to achieve such equality. Gender egalitarianism in Taiwan therefore remains at the abstract or philosophical level with no specification of what gender equality means in concrete terms. Testing the hypothesis that people in mainland China have become more egalitarian than have people in Taiwan with respect to the division of marital roles, the authors investigated the differences in marital role attitudes and expected behavior among selected college students in mainland China and Taiwan. Survey responses were obtained from 185 male and 154 female students from Taiwan and 150 male and 138 female students from mainland China of different years and majors on four dimensions of marital role attitudes and six areas of traditional husband and wife role behaviors. The dimensions were determined through exploratory and confirmatory factor analyses. The data indicate that although most of the hypothesized societal differences are supported, some are not. The authors speculate that possible regressive changes in mainland China and progressive changes in Taiwan during the past decade were responsible for the discrepancy between hypotheses and results.     

Serum levels of interferon-α and-γ in acute and chronic hepatitis B virus infection

To evaluate the potential implication ofin vivo interferon production in the pathogenesis of different forms of acute and chronic hepatitis B virus infection, serum levels of interferon- and- were measured using immunoassay techniques in 20 patients with acute hepatitis B who subsequently cleared the virus (group Ia), 8 patients with acute hepatitis B who became HBsAg carriers (group Ib), 55 patients with chronic hepatitis B (group II), and 15 healthy controls. None of the controls had interferon- or- detectable in serum, while 15% and 100% of group Ia patients, 25% and 100% of group Ib patients, and 22% and 15% of group II patients, had raised serum levels of interferon- and-, respectively. Serum interferon- was detected significantly more frequently in group Ia and Ib patients than in controls and in group II patients. Among patients with acute hepatitis B, serum levels of interferon- and- showed no significant difference between group Ia and group Ib patients. Among patients with chronic hepatitis B, interferon- was detected significantly more frequently in patients with serum HBV-DNA (31.4% or 11/35) than in those without (5% or 1/20), whereas interferon- was detected significantly more frequently in patients with chronic active hepatitis (28% or 7/25) than in those with chronic persistent hepatitis (3.3% or 1/30). In conclusion, in acute hepatitis B, serum levels of interferon- and- did not show a significant difference between patients who subsequently cleared the virus and those who became HBsAg carriers. In chronic hepatitis B, the raised serum levels of interferon- correlated with the presence of viral replication, while the raised serum levels of interferon- correlated with the presence of histological evidence of active hepatitis.