基因诊断技术在脊柱结核诊断中的应用现状

脊柱结核是一种常见的肺外结核病。近年来,随着脊柱结核患者逐年增多,不典型脊柱结核患者亦逐渐增多,而不典型脊柱结核诊断较为困难,需要与一般细菌感染、肿瘤以及非结核分枝杆菌感染相鉴别。基因诊断技术是一项诊断脊柱结核的重要工具,对临床不典型脊柱结核的诊断有较高价值。本文将对脊柱结核的流行现状、诊断及基因诊断技术进行综述,以帮助临床工作者对脊柱结核做出更加准确的诊断。     

A two decade survey of respiratory adenovirus in Taiwan: the reemergence of adenovirus types 7 and 4

From November 1999 to December 2001, three outbreaks of adenovirus (Ad) respiratory infection occurred in southern Taiwan. To determine the circulating serotypes and molecular epidemiology, a total of 524 virus strains were randomly selected from 1,064 strains isolated from 1981 to 2001, and were studied using restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR)-RFLP. The major subgenus found was subgenus B (45%), followed by subgenus E (29%) and subgenus C (25%). Ad3 and Ad7 were the major types found during the 1st outbreak, which occurred from November 1999 to March 2000, while Ad4 was found mainly during the 2nd and 3rd outbreaks in October 2000 and September 2001, respectively. Both Ad7 and Ad4 were reemerged serotypes, whereas Ad3 was consistently isolated during the survey, although it declined drastically from 36 to 2% in 2001. Genotype analysis in this study showed that the only strain of Ad7 found in 1983 was Ad7a, but all randomly selected strains of Ad7 isolated during 1999-2000 were Ad7b. The clinical features of 217 patients were analyzed during the 1999-2000 outbreaks. About 79% of the total cases were less than 7 years old. The ratio of male to female was 2:1. Severe infections, such as pneumonia and acute bronchitis, accounted for nearly half of the cases (43%). These results show the reemergence and changing of serotypes, the clinical association of respiratory adenovirus infections, and the molecular epidemiology of Ad7 genotypes in Taiwan during the past two decades.     

Rapid diagnosis of parasitic diseases: current scenario and future needs

Background

Parasitic diseases are one of the world's most devastating and prevalent infections, causing millions of morbidities and mortalities annually. In the past, many of these infections have been linked predominantly to tropical or subtropical areas. Nowadays, however, climatic and vector ecology changes, a significant increase in international travel, armed conflicts, and migration of humans and animals have influenced the transmission of some parasitic diseases from ‘book pages’ to reality in developed countries. It has also been noted that many patients who have never travelled to endemic areas suffer from blood-borne infections caused by protozoa. In the light of existing knowledge, this new trend can be explained by the fact that in the process of migration a large number of asymptomatic carriers become a part of the blood bank donor and transplant donor populations. Accurate and rapid diagnosis represents the crucial weapon in the fight against parasitic infections.

Polyethylenes Having Well‐Defined Bimodal Molecular Weight Distributions Formed with Bis(phenoxy‐imine) Zr Complexes

Summary: Bis(phenoxy‐imine) Zr complexes with MAO activation can produce polyethylenes with well‐defined bimodal molecular weight distributions. Polymerization behavior indicates that minor changes in the ligand structures can have a significant effect on the modality of the resulting polyethylenes. Although there is no direct relationship between the bimodal catalytic behavior and the structure of a precatalyst complex in solution, a precatalyst complex having a methyl or methoxy group para to the phenoxy‐oxygen inclined to exhibit bimodal behavior whereas that with a pentafluorophenyl group on the imine‐nitrogen displayed unimodal behavior. Polymerization results suggest that bimodal behavior is linked to the presence of two kinds of cationic active species, which arise from different modes of ligand coordination. A qualitative correlation was found between the calculated amounts of possible cationic active species and the uni‐ and bimodal catalytic behavior. Based on the results obtained, we concluded that the bimodal polyethylenes are produced by two kinds of cationic active species having two available cis‐located sites with cis‐N, trans‐O and cis‐N, cis‐O arrangements. The results introduced herein are rare examples of the production of well‐defined bimodal polyethylenes using a single precatalyst.

Bis(phenoxy imine) Zr complexes can produce well‐defined bimodal polyethylenes.     

The effect of ethanol-induced CYP2E1 on proteasome activity: the role of 4-hydroxynonenal

Previous studies have shown that the induction of P450 cytochrome 2E1 (CYP2E1) is associated with the loss of proteasomal activities. To correlate the loss of proteasomal activity with CYP2E1 induction, ethanol was fed intragastrically for 1, 3, 7, and 15 days. The maximum induction of CYP2E1 (3.5-fold) occurred after 15 days of ethanol feeding. However, there was no significant decrease in the 26 S chymotrypsin-like and trypsin-like activity over this period of time. When ethanol was given to rats for 1 month, CYP2E1 was significantly induced, and the proteasomal activity was significantly decreased. These results indicate that proteasomal activity was not directly affected by ethanol or CYP2E1 induction. Since 4-hydroxynonenal (4-HNE) concentration was significantly increased at 1 month of ethanol feeding, it was suspected that 4-HNE adduct formation with proteasome subunits could be the mechanism of proteasome inhibition. Using an antibody to 4-HNE adducted proteins in Western blot analysis of the 26 S proteasome fraction isolated from the liver of alcohol fed rats, one extra band appeared around 44 kDa. When the antibody to an ATPase Rpt4 was used to stain the stripped membrane, the same band that was detected with the 4-HNE antibody was detected with the Rpt4 antibody. An adduct of 4-HNE formed with the Rpt4 subunit of 26 S could impede the association of 19 S and 20 S and thus account for the observed decrease of proteasomal activity.     

Association study of dopamine D3 receptor gene and schizophrenia

Several groups have reported an association between schizophrenia and the MscI polymorphism in the first exon of the dopamine D3 receptor gene (DRD3). We studied this polymorphism using a North American sample (117 patients plus 188 controls) and an Italian sample (97 patients plus 64 controls). In the first part of the study, we compared allele frequencies of schizophrenia patients and unmatched controls and observed a significant difference in the total sample (P = 0.01). The second part of the study involved a case control approach in which each schizophrenia patient was matched to a control of the same sex, and of similar age and ethnic background. The DRD3 allele frequencies of patients and controls revealed no significant difference between the two groups in the Italian (N = 53) or the North American (N = 54) matched populations; however, when these two matched samples were combined, a significant difference was observed (P = 0.026). Our results suggest that the MscI polymorphism may be associated with schizophrenia in the populations studied. © 1995 Wiley-Liss, Inc.     

Molecular cloning and complete nucleotide sequence of the genome of Japanese encephalitis virus Beijing-1 strain

The genomic RNA of the Japanese encephalitis virus (JEV) Beijing-1 strain was reversely transcribed and the synthesized cDNA was molecularly cloned. Six continuous cDNA clones that cover the entire virus genome were established and sequenced to determine the complete nucleotide sequence of the JEV RNA. The precise genomic size was estimated as 10,965 bases long. With flanking 95 bases at the 5 and 583 bases at the 3 non-coding regions, one long open reading frame (ORF) was revealed encoding a virus polyprotein with 3,429 amino acid residues. Because of sequence homologies observed between JEV and other flaviviruses, the genome organization of JEV appears to be identical with other flaviviruses. Genetic variation detected among flavivirus genomes is consistent with the established serological relatedness between JEV and other members of flaviviruses. The secondary structure of the JEV genome is deduced and discussed concerning its involvement in genome replication.     

Molecular epidemiology of adenoviruses isolated from hospitalized children with severe lower acute respiratory infection in Santiago, Chile

Genome analysis was performed on 69 adenovirus isolates from pharyngeal secretions of young children hospitalized with severe lower acute respiratory disease in Santiago, Chile, between 1984 and 1986. As expected, most isolated strains belonged to subgenus B (68.1%). Among the isolates of 1984, Ad7c was the dominant genotype (12 out of 23). The majority of isolates of 1986 were of the recently described genomic variant 3f.