Biomedical subjects

Jun Zhu

Publications and source records attributed to Jun Zhu.

At least 145 records · Page 8Linked to original sources

PubMed2004

[Maternal mortality in rural areas of China].

OBJECTIVE: To understand with clearness the trend and epidemiological characteristics of maternal mortality, as well as the leading causes of maternal deaths in rural areas of China from 1996 to 2001. METHODS: The data analyzed were those from the population-based epidemiological survey conducted by the national maternal mortality surveillance network which covered a total population of about 35,000,000 in China. RESULTS: The maternal mortality ratio (MMR) in rural areas of China dropped by 28.4% from 86.4 per 100,000 live births in 1996 to 61.9 in 2001. The leading causes of maternal deaths were obstetric hemorrhage, preeclampsia and embolism of amniotic fluid. The MMR for obstetric hemorrhage decreased from 48.3 per 100,000 live births in 1996 to 33.0 in 2001. The pregnant women mainly gave childbirths and died in their home, accounting for 44.6% and 30.1% respectively in 2001. CONCLUSION: The MMR showed a downward trend in rural areas of China during the period from 1996 to 2000, and so also did the MMR for obstetric hemorrhage. Reducing obstetric hemorrhage and increasing the rate of hospitalized delivery are the most important methods for reducing the MMR in rural areas in China.

Adult↗

PubMed2004

[Impacts of birth defects on perinatal deaths in Chinese population].

OBJECTIVE: To examine the time trends of perinatal mortality and the frequency of birth defects occurring in perinatal deaths, and to provide a national perspective on the impacts of congenital anomalies on perinatal mortality from 1990 through 2001. METHODS: Data were from Chinese Birth Defects Monitoring network-a hospital-based congenital anomalies registry system. During 1990 - 2001, all live or still births with 28 weeks of gestation or more, born in monitoring units, were studied within 7 days after delivery. The proportion of perinatal deaths due to birth defects, which was defined as the number of perinatal deaths associated with congenital anomalies per 100 perinatal deaths, was calculated by birth area (urban versus rural), geographic-economic status (coast areas, inner land areas and remote areas), to evaluate the impacts of birth defects on perinatal mortality. RESULTS: Perinatal mortality declined from 22.85 per 1000 in 1990 to 13.26 per 1000 in 2001, which showed a significant downward trend. Similar trend was also observed in the rate of stillbirth and the ratio of early neonatal death. However, the proportion of perinatal deaths due to birth defects had an increasing trend although the perinatal birth defects-specific death rate was declining, especially during 1996 - 2001. This result was also seen in urban and rural area, in coast regions, in inner land regions and in remote regions of China. Higher rate of birth defects occurring in perinatal deaths was observed in urban area than in rural area. Significant difference of this rate was also found among different geographic-economic regions, with the highest one in inland regions. CONCLUSION: Birth defects were accounted for an increasing proportion of perinatal deaths in China, and had become one of the major causes of perinatal deaths.

China↗

PubMed2004

[The relationship of p53 and the cytotoxicity mediated by TM-TNF-alpha and S-TNF-alpha].

AIM: To explore the relationship of p53 and the cytotoxicity mediated by TM-TNF-alpha and S-TNF-alpha. METHODS: P53 mutation in tumor cell was detected by PCR-SSCP. Wide type p53 expression plasmid was transfected to tumor cells with mutant p53 gene, while the mutant type p53 plasmid to tumor cell with wide type p53 gene.Then,the effects of transfection on the cytotoxicity of two types of TNF were detected. RESULTS: Mutation in the p53 gene were found in most of tumor cells (Raji, HL-60, K562) which were resistant to S-TNF-alpha. The tumor cells transfected with wild type p53 plasmid were more sensitive to S-TNF-alpha while the tumor cells transfected with mutant type p53 plasmid were less sensitive to S-TNF-alpha. But the cytotoxicity of TM-TNF-alpha was not affected by the transfection. CONCLUSION: The cytotoxicity mediated by TM-TNF-alpha is not dependent on wide type p53, which may account for the broader tumorcidal spectrum of TM-TNF-alpha than that of S-TNF-alpha.

Breast Neoplasms↗

PubMed2004

[Epidemiological analysis of syndactyly in Chinese perinatals].

OBJECTIVE: To study the epidemiological features of syndactyly (SD) in Chinese perinatals. METHODS: Data were collected through Chinese Birth Defects Monitoring Network, a hospital-based congenital malformation registry system. From 1987 through 2001 (except 1994, 1995), all live or still births with 28 weeks of gestation or more born in participating hospitals were assessed within 7 days after delivery. RESULTS: Totally 2311 perinatals with SD were identified among 7 478 746 births, and 57.2% of them were in association with other anomalies. The overall prevalence rate of SD was 3.09/10 000, the rate of isolated SD and associated SD was 1.32/10 000, and 1.77/10 000 respectively. The prevalence rates in urban and rural areas, in male and female births were 3.22/10 000 and 2.79/10 000, 3.42/10 000 and 2.59/10 000 respectively. An increasing trend was found during that period. The perinatal fatality rate of SD was 20.7%, that of isolated form was 5.7%, while that of associated form was 31.9%. The proportion of SD occurring in right side was the same as that in left side, and the proportion of SD in upper limbs equaled to that in lower limbs. CONCLUSIONS: The prevalence rate of SD in Chinese perinatals was similar to that reported in foreign literatures. Associated form of SD was more frequently seen. The prevalence of SD in urban areas was higher than in rural areas. Male excess was identified in both isolated and associated forms of SD. No selective predominance was observed either by affected side or by affected limbs.

China↗

PubMed2004

[Epidemiological analysis of polydactylies in Chinese perinatals].

OBJECTIVE: To investigate the epidemiologyical characteristics of polydactyly. METHODS: The method of Hospital-based surveillance within Chinese Birth Defects Monitoring Network (CBDMN) was adopted. All perinatals (from 28 weeks of gestation to a period of 7 days after birth) in the participating hospitals were investigated from 1996 to 2000. RESULTS: A total of 2097 cases were identified in 2218616 perinates, the prevalence was 9.45 per 10000. The prevalence of male was significantly higher than the female's. The urban prevalence was 9.60 per 10000, and the rural prevalence was 9.05 per 10000. Significant difference and increasing time trend were observed in annual prevalence rate during 1996-2000. Of the 2097 cases, 1853 (88.4%) were in the isolated form, and the rest (11.6%) of them were combined with other defects. Among 1942 perinatals affected by polydactyly, 679 (34.96%) cases occurred in the left limbs, 886 (45.62%) cases occurred in the right limbs, and 377 (19.41%) cases occurred bilaterally. CONCLUSION: The prevalence rates of polydactylies in Chinese perinatals show male predominance and geographic variations. Most of the polydactyly cases were in the from of single defect; however, those accompanied by other defects had a higher perinatal fatality rate.

China↗

PubMed2004

[An epidemiological study on omphalocele in China during 1996 to 2000].

OBJECTIVE: To understand the trend of incidence of omphalocele and its epidemiological characteristics in China during 1996 to 2000. METHODS: Surveillance data of omphalocele were collected from 460 hospitals at county level or above county level, involving all births with 28-week gestation to 7 days after delivery, including live births, fetal deaths and stillbirths in 31 provinces, autonomous regions and municipalities all over the country during 1996 to 2000. RESULTS: Overall incidence of omphalocele in China was 1.52 per 10 000 live births, with an increasing trend during 1996 to 2000. Incidence of omphalocele was 1.40 per 10 000 and 1.83 per 10 000 in the rural and urban areas, respectively, with a statistically significant difference (P < 0.05), and 1.54 per 10 000 and 1.41 per 10 000 in boys and girls, respectively. Babies of omphalocele associated with other malformation accounted for 30.77% of the total cases. Perinatal fatality rate of omphalocele was 51.18%, with prenatal diagnostic rate of 31.07%. CONCLUSIONS: Prevalence of omphalocele appeared an increasing trend in China during the period from 1996 to 2000. Occurrence of omphalocele was more frequent in rural areas than that in urban areas. Perinatal fatality rate in babies with omphalocele was higher and fatality of associated omphalocele was higher than that of simple one. It is suggested that management of perinatal care and level of prenatal diagnosis for omphalocele should be improved.

China↗

PubMed2004

[Clinical analysis of liver non-Hodgkin's lymphoma].

BACKGROUND & OBJECTIVE: Incidence of liver non-Hodgkin's lymphoma (NHL) is increasing. This study was to explore clinical features, diagnosis, treatment, and prognosis of liver NHL. METHODS: Records of 45 patients with liver NHL treated in our hospital from Jan. 1998 to May 2002, 9.6% of all NHL patients treated in the same period, were retrospectively analyzed with statistic software package of SPSS10.0. RESULTS: Of 45 patients, 32 were male,and 13 were female, the median age was 50 years. Immunophenotyping revealed that 24 cases were T cell original, 19 were B cell original, and 2 were undefined. According to International Work Formulation (IWF), 92% of 45 patients belonged to intermediate-grade. Clinical features of liver NHL were presented with fever, jaundice, hepatosplenomegalia, and liver dysfunction. Combination treatment based on chemotherapy was the major therapy. Median survival time was 4 months, overall 1-, and 2-year survival rates were 22%, and 18%. CONCLUSION: Early diagnose liver NHL is difficult, its treatment effect and prognosis are poor, combination therapy should be given as early as possible.

Adolescent↗

PubMed2004

[Clinical trial on ibandronate in patients with tumor-associated hypercalcemia].

OBJECTIVE: Ibandronate, a third generation bisphosphonate, inhibits bone resorption in human and animal studies. This study is to evaluate the efficacy and safety of ibandronate as a single agent in patients with tumor-associated hypercalcemia. METHODS: An open, multicenter, non-controlled clinical trial was conducted in 22 patients. The patients received 2 mg ibandronate intravenously if the corrected calcium was less than 3.0 mmol/L but more than 2.7 mmol/L; they received 4 mg ibandronate iv if corrected calcium was more than 3.0 mmol/L. RESULTS: There was 100% efficacy in these two dose groups but the calcium correcting effect was more pronounced in the 4-mg dose group than the 2-mg dose group. The most common adverse reactions were fever and skin itching with an incidence of 4.5%. CONCLUSION: Ibandronate is active in patients with tumor-associated hypercalcemia and the adverse effects are well tolerated.

Bone Neoplasms↗

PubMed2003

Optical feedback laser with a quartz crystal plate in the external cavity.

We studied the optical feedback characteristics of a single-mode He-Ne laser with a quartz crystal plate in the external cavity. The fringe frequency of the laser system can be doubled when the quartz crystal plate is positioned at a certain angle between the crystalline axis and the beam in the crystal plate. Theoretical analysis shows that the birefringent effect of the quartz crystal plate and the laser beam's second pass through the external cavity result in this phenomenon. The experimental results are in good agreement with the theoretical analysis. A quartz crystal plate can double the resolution of a self-mixing sensing system.

Journal Article↗

PubMed2003

[Preoperative etiological diagnosis of hemifacial spasm: a comparative study between magnetic resonance tomographic angiography and intra-operative findings].

OBJECTIVE: To summarize retrospectively the value of magnetic resonance tomographic angiography (MRTA) in the preoperative etiological diagnosis for hemifacial spasms (HFS). METHODS: 336 cases of HFS, 127 male and 209 female, aged 46.2 (16-75), with a course of 1-29 years (6.2 years on average) and with the unilateral symptoms except one case were subjected to routine MRTA check up preoperatively. The MRTA findings were compared with the operative findings. RESULTS: Pre-operative evaluation by MRTA discerned 273 offending vessels with a positive rate of 81.3%, which were completely consistent with the intra-operative findings. The false positive and false negative rates were 8.0% and 9.8% respectively. Three cases of HFS due to secondary cause were found: one of CPA meningioma at the cerebellopontine angle and two cases of cholesteatoma. CONCLUSION: MRTA imaging provides more useful information concerning the etiology of hemifacial spasm than any other available diagnostic modalities. It is an effective and reliable means for pre-operative evaluation of the existence and sources of offending vessels in hemifacial spasm patients, and thus benefits the planning and guiding of intra-operative manipulation.

Adolescent↗

PubMed2003

Single molecule profiling of alternative pre-mRNA splicing.

Alternative pre-messenger RNA splicing is an important mechanism for generating protein diversity and may explain in part how mammalian complexity arises from a surprisingly small complement of genes. Here, we describe "digital polony exon profiling,"a single molecule-based technology for studying complex alternative pre-messenger RNA splicing. This technology allows researchers to monitor the combinatorial diversity of exon inclusion in individual transcripts. A minisequencing strategy provides single nucleotide resolution, and the digital nature of the technology allows quantitation of individual splicing variants. Digital polony exon profiling can be used to investigate the physiological and pathological roles of alternately spliced messenger RNAs, as well as the mechanisms by which these messenger RNAs are produced.

Acrylamide↗

PubMed2003

Significance of 14-3-3 self-dimerization for phosphorylation-dependent target binding.

14-3-3 proteins via binding serine/threonine-phosphorylated proteins regulate diverse intracellular processes in all eukaryotic organisms. Here, we examine the role of 14-3-3 self-dimerization in target binding, and in the susceptibility of 14-3-3 to undergo phosphorylation. Using a phospho-specific antibody developed against a degenerated mode-1 14-3-3 binding motif (RSxpSxP), we demonstrate that most of the 14-3-3-associated proteins in COS-7 cells are phosphorylated on sites that react with this antibody. The binding of these phosphoproteins depends on 14-3-3 dimerization, inasmuch as proteins associated in vivo with a monomeric 14-3-3 form are not recognized by the phospho-specific antibody. The role of 14-3-3 dimerization in the phosphorylation-dependent target binding is further exemplified with two well-defined 14-3-3 targets, Raf and DAF-16. Raf and DAF-16 can bind both monomeric and dimeric 14-3-3; however, whereas phosphorylation of specific Raf and DAF-16 sites is required for binding to dimeric 14-3-3, binding to monomeric 14-3-3 forms is entirely independent of Raf and DAF-16 phosphorylation. We also find that dimerization diminishes 14-3-3 susceptibility to phosphorylation. These findings establish a significant role of 14-3-3 dimerization in its ability to bind targets in a phosphorylation-dependent manner and point to a mechanism in which 14-3-3 phosphorylation and dimerization counterregulate each other.

14-3-3 Proteins↗

PubMed2003

Cross-talk between JNK/SAPK and ERK/MAPK pathways: sustained activation of JNK blocks ERK activation by mitogenic factors.

Mixed lineage kinases (MLKs) are a family of serine/threonine kinases that function in the SAPK signaling cascade. MLKs activate JNK/SAPK in vivo by directly phosphorylating and activating the JNK kinase SEK-1 (MKK4 and -7). Importantly, the MLK member MLK3/SPRK has been shown recently to be a direct target of ceramide and tumor necrosis factor-alpha (TNF-alpha) and to mediate the TNF-alpha and ceramide-induced JNK activation in Jurkat cells. Here we report that MLK3 can phosphorylate and activate MEK-1 directly in vitro and also can induce MEK phosphorylation on its activation sites in vivo in COS-7 cells. Surprisingly, this induction of MEK phosphorylation does not result in ERK activation in vivo. Rather, in cells expressing active MLK3, ERK becomes resistant to activation by growth factors and mitogens. This restriction in ERK activation requires MLK3 kinase activity, is independent of Raf activation, and is reversed by JNK pathway inhibition either at the level of SEK-1, JNK, or Jun. These results demonstrate that sustained JNK activation uncouples ERK activation from MEK in a manner requiring Jun-mediated gene transcription. This in turn points to the existence of a negative cross-talk relationship between the stress-activated JNK pathway and the mitogen-activated ERK pathway. Thus, our findings imply that some of the biological functions of JNK activators, such as TNF-alpha and ceramide, may be attributed to their ability to block cell responses to growth and survival factors acting through the ERK/MAPK pathway.

Animals↗

PubMed2003

ToxR regulon of Vibrio cholerae and its expression in vibrios shed by cholera patients.

Toxigenic Vibrio cholerae cause cholera, a severe diarrheal disease responsible for significant morbidity and mortality worldwide. Two determinants, cholera enterotoxin (CT) and toxin coregulated pilus (TCP) are critical factors responsible for this organism's virulence. The genes for these virulence determinants belong to a network of genes (the ToxR regulon) whose expression is modulated by transcriptional regulators encoded by the toxRS, tcpPH, and toxT genes. To define the ToxR regulon more fully, mutants defective in these regulatory genes were transcriptionally profiled by using V. cholerae genomic microarrays. This study identified 13 genes that were transcriptionally repressed by the toxT mutation (all involved in CT and TCP biogenesis), and 27 and 60 genes that were transcriptionally repressed by the tcpPH and toxRS mutations, respectively. During the course of this analysis, we validated the use of a genomic DNA-based reference sample as a means to standardize and normalize data obtained in different microarray experiments. This method allowed the accurate transcriptional profiling of V. cholerae cells present in stools from cholera patients and the comparison of these profiles to those of wild-type and mutant strains of V. cholerae grown under optimal conditions for CT and TCP expression. Our results suggest that vibrios present in cholera stools carry transcripts for these two virulence determinants, albeit at relatively low levels compared with optimal in vitro conditions. The transcriptional profile of vibrios present in cholera stools also suggests that the bacteria experienced conditions of anaerobiosis, iron limitation, and nutrient deprivation within the human gastrointestinal tract.

Bacterial Proteins↗

PubMed2003

L-asparaginase-based regimen in the treatment of refractory midline nasal/nasal-type T/NK-cell lymphoma.

Nasal, nasal-type T-cell/natural killer cell (T/NK-cell) lymphoma is a rare disease, and its prognosis is poor. Between March 1992 and March 2002 we investigated a new L-asparaginase-based salvage regimen to treat the disease and improve response to treatment and 5-year overall survival rate. Eighteen patients with refractory midline nasal, nasal-type T/NK-cell lymphoma, who were resistant to a cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP)-like regimen, received an L-asparaginase-based salvage regimen (L-asparaginase, vincristine, and dexamethasone). Primary involved field radiation was given to the patients after chemotherapy. Ten (55.6%) of the patients achieved complete response (CR). Five patients (27.8%) achieved partial response (PR). The overall response rate (CR + PR) was 83.3%. The 5-year overall survival rate was 55.6%. Results of the preliminary clinical study indicated that the L-asparaginase-based salvage regimen significantly improved the response rate and 5-year survival rate. The findings suggested that the therapy is a promising new salvage regimen for treating refractory midline nasal, nasal-type T/NK-cell lymphoma.

Adolescent↗

PubMed2003

Quorum sensing-dependent biofilms enhance colonization in Vibrio cholerae.

Vibrio cholerae is the causative agent of the diarrheal disease cholera. By an incompletely understood developmental process, V. cholerae forms complex surface-associated communities called biofilms. Here we show that quorum sensing-deficient mutants of V. cholerae produce thicker biofilms than those formed by wild-type bacteria. Microarray analysis of biofilm-associated bacteria shows that expression of the Vibrio polysaccharide synthesis (vps) operons is enhanced in hapR mutants. CqsA, one of two known autoinducer synthases in V. cholerae, acts through HapR to repress vps gene expression. Vibrio biofilms are more acid resistant than planktonic cells. However, quorum sensing-deficient biofilms have lower colonization capacities than those of wild-type biofilms, suggesting that quorum sensing may promote cellular exit from the biofilm once the organisms have traversed the gastric acid barrier of the stomach. These results shed light on the relationships among biofilm development, quorum sensing, infectivity, and pathogenesis in V. cholerae.

Acyltransferases↗

PubMed2003

Genetic algorithms applied to multi-class clustering for gene expression data.

A hybrid GA (genetic algorithm)-based clustering (HGACLUS) schema, combining merits of the Simulated Annealing, was described for finding an optimal or near-optimal set of medoids. This schema maximized the clustering success by achieving internal cluster cohesion and external cluster isolation. The performance of HGACLUS and other methods was compared by using simulated data and open microarray gene-expression datasets. HGACLUS was generally found to be more accurate and robust than other methods discussed in this paper by the exact validation strategy and the explicit cluster number.

Algorithms↗

PubMed2003

BioMagResBank database with sets of experimental NMR constraints corresponding to the structures of over 1400 biomolecules deposited in the Protein Data Bank.

Experimental constraints associated with NMR structures are available from the Protein Data Bank (PDB) in the form of "Magnetic Resonance" (MR) files. These files contain multiple types of data concatenated without boundary markers and are difficult to use for further research. Reported here are the results of a project initiated to annotate, archive, and disseminate these data to the research community from a searchable resource in a uniform format. The MR files from a set of 1410 NMR structures were analyzed and their original constituent data blocks annotated as to data type using a semi-automated protocol. A new software program called Wattos was then used to parse and archive the data in a relational database. From the total number of MR file blocks annotated as constraints, it proved possible to parse 84% (3337/3975). The constraint lists that were parsed correspond to three data types (2511 distance, 788 dihedral angle, and 38 residual dipolar couplings lists) from the three most popular software packages used in NMR structure determination: XPLOR/CNS (2520 lists), DISCOVER (412 lists), and DYANA/DIANA (405 lists). These constraints were then mapped to a developmental version of the BioMagResBank (BMRB) data model. A total of 31 data types originating from 16 programs have been classified, with the NOE distance constraint being the most commonly observed. The results serve as a model for the development of standards for NMR constraint deposition in computer-readable form. The constraints are updated regularly and are available from the BMRB web site (http://www.bmrb.wisc.edu).

Databases, Protein↗