Biomedical subjects

X Pan

Publications and source records attributed to X Pan.

At least 91 records · Page 5Linked to original sources

PubMed1999

In vivo gene transfer of a suicide gene under the transcriptional control of the carcinoembryonic antigen promoter results in bone marrow transduction but can avoid bone marrow suppression.

We constructed the CEA419/CD retrovirus vector carrying the cytosine deaminase (CD) gene directed by the carcinoembryonic antigen (CEA) promoter. pCD2 retrovirus vector carrying the CD gene directed by the retrovirus long terminal repeat promoter was also used. When mice bearing intraperitoneally disseminated colorectal carcinomas (CRCs) were infused intraperitoneally with pCD2 or CEA419/CD retrovirus-producing cells, a CD fragment was detected in CRCs and bone marrow cells. It was shown that the CD gene was expressed both in CRCs and in the bone marrow of animals infused with pCD2 retrovirus-producing cells, while the CD gene was expressed solely in CRCs of animals infused with CEA419/CD retrovirus-producing cells. These results indicate that the use of a tumor-selective promoter may warrant the safety of in vivo gene therapy using suicide genes.

Adenocarcinoma↗

PubMed1999

[Analysis on the mis-reported cases of infectious diseases in Hainan Province].

OBJECTIVE: To investigate the reasons for mis-reporting cases and to furnish theoretical foundation for the control of infectious diseases. METHOD: 15 hospitals and 2,937 residents were selected and studied through random and systematic sampling methods in Hainan Province. RESULTS: Data showed that the mis-reporting rate in clinics was 44.40%, among which the private-ran clinics had a highest mis-reported records. They not only failed to fill in the forms of reporting infectious diseases, but also neglected to report epidemic information. Malaria, hepatitis, syphilis and gonorrhea were among the highest mis-reported diseases with malaria the most (91.73% mis-reporting rate). Remarkable difference was noticed in various hospitals (P < 0.01). CONCLUSION: The author concluded that many infectious diseases were seriously mis-reported, indicating the reporting system should be improved and the quality be enhanced.

China↗

PubMed1999

[Investigation on the effect and strategy of polio eradication in Hainan Province].

OBJECTIVE: Hainan Province was a hyperendemic area of poliomyelitis, with an average incidence rate of 0.28 per hundred thousand before 1993. A series of strategy was developed for polio eradication in the whole province in July 1993. METHODS: Health education, regular and strenthening immunization programs, AFP surveillance. RESULTS: 1. OPV vaccination rate increased to 97.93%, 2. incidence rate of polio had a 80.93% reduction, 3. seasonal peak of epidemic was cut down, 4. endemic cycle was broken and 5. the endemic area became smaller. The number of counties (cities) where polio cases occured reduced for 81.33% in 1993 than that in 1989. Four boosters had been implemented from 1993 to 1997, to eliminated blank spots of immunization. The average geometric antibody of titre increased to 1:400 and above. After the establishment of polio surveillance system in 1991, 1. the reporting rate of non-AFP increased from 0 to 1.27 per hundred thousand, 2. rate of double specimens collection increased from 0 to 87.10%, 3. positive rate of virus isolation from 23.07% to 34.80%, 4. the positive specimens were appraised by National Polio Surveillance Center and no wild strain was found. Health education has made remarkable impact and immunization knowledge among parents had a 75 percentage point increase. CONCLUSION: Results showed that strategy of polio eradication has made positive effects and provided valuable experiences for the control or elimination of diseases which can be prevented by vaccines.

Child↗

PubMed1999

[A serological investigation of Legionella infection in six-species of poultries and domestic animals in Luzhou City, Sichuan Province].

OBJECTIVE: To understand the prevalence rates of Legionella infection in poutries and domestic animals in Luzhou city. METHODS: Serological investigation of antibodies against Legionella pneumophila serogroups 1-14 and Legionella micdadei was carried out, using microagglutination test (MAT) in six species of poutries and domestic animals. RESULTS: Results showed that the infection with multiple serogroups was present. However, each species had its own serogroup with positive rates of different serogroups ranging from 2.00% to 28.75%. Positive rates of domestic animals and poultry accounted for 4.49% and 6.47% respectively. CONCLUSION: It was suggested that poultries and domestic animals were widely infected with Legionella. It is important to carry out epidemiological surveillance in these domestic animals, poultries and environment for a better control program of this disease.

Animals↗

PubMed1999

[Cloning of rat beta-defensin rBD-1 cDNA].

This is a study aimed at the molecular mechanisms of beta-defensins gene expression and it's gene transfer experiments for preventing mucosal infection. A rat rBD-1 cDNA was cloned. The total RNA was isolated from rat kidney. The cDNA fragment was amplified by RT-PCR with specific primers. The purified RT-PCR product was cloned in pGEM-T Easy vector. The results of restriction endonuclease pattern analysis of the recombinant plasmid, DNA sequencing, and aligning of the putative amino acid sequence with hBD-1 and mBD-1 demonstrated that rat beta-defensin rBD-1 gene was cloned successfully.

Amino Acid Sequence↗

PubMed1999

Changing pattern of heart diseases in Shanghai from the 1950s to 1980s.

OBJECTIVE: To determine the pattern of dynamic change in types of heart diseases in the past 4 decades for providing a reference to treatment and prevention of heart diseases in China. METHODS: All adult cardiac patients admitted to the Zhong Shan Hospital and Hua Shan Hospital from 1948 to 1989 were analyzed. The constituent ratio of different heart diseases in the 1950s, 1960s, 1970s and 1980s was compared. RESULTS: The percentage of heart diseases among medical inpatients increased in each of the recent 4 decades, from 9.89%, 15.69%, 20.90% to 23.54% respectively. The constituent ratio of different heart diseases changed, coronary heart disease constituted the highest proportion, next came rheumatic heart disease, and congenital heart disease was in third place. Congenital heart disease, myocarditis, cardiac dysrhythmia without organic heart disease, cardiomyopathy and endocarditis increased, rheumatic heart disease, pulmonary heart disease and hypertensive heart disease apparently decreased; syphilitic heart disease could rarely be encountered. CONCLUSION: China is now facing a low overall death rate, a long life expectancy and an aging population. The incidence of heart diseases increased gradually and patterns of heart diseases kept changing. The overall trend is that heart diseases which were not related to infection are increasing while heart diseases related to bacterial infection are decreasing.

Arrhythmias, Cardiac↗

PubMed1999

[Isolation and sequencing of a novel form of cytochrome p-450 4F family from human liver].

OBJECTIVE: To isolate and sequence a novel gene of cytochrome p-450 4F family. METHODS: A cDNA was isolated by touchdown PCR from a cDNA library of human fetal liver using specific primers. The DNA sequencing was done by an auto-sequence machine through forward and reverse directions. The expression of cDNA encoded protein was tested in yeast cells. RESULTS: Sequencing of the full length cDNA revealed a sequence of 1,980 nucleotides coding for a protein of 520 amino acids with a molecular weight of 59,700 Da. The cDNA-deduced amino acid sequence showed 92% homology to that of human polymorphonuclear leukocytes (PMN) LTB4-hydroxylase (CYP4F3) and 91% homology to that of human liver LTB4 hydroxylase (CYP4F2). The expression of protein in the yeast cells showed a fusion protein with a molecular weight of about 86,000 Da and 60,000 Da after a proteolytic removal of the GST affinity tag. It was confirmed by RT-PCR that the gene was expressed in the adult liver. CONCLUSION: Our results clearly show a novel form of cytochrome p-450 4F in human liver.

Amino Acid Sequence↗

PubMed1999

[Surgical treatment of ovarian malignant tumors metastasized to the gastro-intestinal tract: a report of 131 cases].

OBJECTIVE: To investigate the value and feasibility of surgical excision of gastro-intestinal metastatic tumors in patients with ovarian malignancy. METHODS: The surgical and clinical data were retrospectively reviewed in 131 cases of ovarian malignant tumor with surgically excised gastrointestinal metastasis (> or = 2 cm in diameter). RESULTS: Ovarian malignant tumor with gastro-intestinal metastasis accounted for 28.9% of the patients with primary ovarian malignancies in the same time period. Of the 131 cases, 126(93.9%) were in stage III and IV. The treatment was surgical excision combined with chemotherapy. Of the 141 operations, 83 (58.9%) were done by stripping of tumors on the gastro-intestinal wall and repair, 31(22.0%) received resection of the involved segment of the bowel with anastomosis, 27(19.2%) with colostomies. Postoperative complications occurred in 26.9% of the operated patients. The overall 2- and 5-year survival rate was 79.7% and 42.5%, respectively. CONCLUSION: Surgical excision of gastro-intestinal tumors metastasized from primary ovarion malignancies is feasible to achieve cytoreduction. Prognosis can be improved when combined with chemotherapy.

Adolescent↗

PubMed1999

[The etiology of impotence in 327 diabetic male adults].

OBJECTIVE: To investigate the etiology of impotence in diabetic male adults. METHODS: 327 diabetic men aged 20 - 70 years were interviewed; 129 (39.6%) of them complained of impotence. All the 129 patients were initially evaluated by diabetologists and then underwent psychosexual assessment by psychiatrists. In addition, evaluation for retinopathy, neuropathy, vascular disease and sex hormone level was carried out. RESULTS: The 327 diabetic patients were divided into four age ranges 25 - 34, 35 - 44, 45 - 54, and 55 - 70. The frequency of diabetic impotence in these groups was 9.7%, 34.2%, 48.0%, 62.7% respectively. Neuropathy was found in 79 (61.2%), psychogenic factor contributed in 66 (51.2%), vascular factor was present in 31 (24.0%), leakage of penile venous cavernosa occurred in 5 (3.9%), and treatment with impotence- related medications was the contributing factor in 2 (1.6%). There are significant differences of glycosylated hemoglobin, peripheral neuropathy, autonomic neuropathy, and proliferative retinopathy between impotent and potent diabetic patients. The degree of psychological problem is more serious in the diabetic impotent patients than in potent patients according to Minnesota multiphasic personality inventory (MMPI) test. No significant difference was found in smoking, alcohol and plasma testosterone level. CONCLUSION: The etiology of diabetic impotence is multifactorial. Neuropathy is the main cause, but vascular and psychological factors also contribute to it significantly.

Adult↗

PubMed1999

[Application of intraclass correlation coefficient to reliability assessment].

To evaluate the reliability of questionnaire and expound the simple method of calculating and testing the intraclass correlation coefficient (ICC), the authors gave an example of how to simply calculate and conduct the hypothesis testing of ICC by using the analysis table of variance. The results demonstrated a high test-retest reliability of the illustrative questionnaire. By using ANOVA table, the calculation and hypothesis testing of the ICC is easy to do. The method can be used in the analysis of quantitative data, and categorical data as well.

Aged↗

PubMed1999

[A study on the relationship between tree age and bark quality in Magnolia officinalis].

Contents of magnolol and honokiol in 76 samples of Magnolia officinalis collected from 11 counties in Zhejiang, Fujian, Sichuan, Guangxi, Hunan, Jiangxi and Hubei are analyzed by means of HPLC. A study on the effect of tree age on effective ingredients in Magnolia offcinalis shows that the influence of tree age on the content of magnolol and honokiol is correlated with the varieties under cultivation, but a small effect on the content of the phenols with an indent at the tip of leaves. The content of magnolol in other types of leaves increases rapidly with increase in age, diameter of the trunk and thickness of the bark, with not many changes found at the age of 12 or up. Increase in age may be favorable to the full expression of oily characteristic. These results provide a scientific base for the determination of optimal time for harvesting bark from artificially established Magnolia officinalis stands.

Age Factors↗

PubMed1999

[Grey relational analysis on early bolting of Angelica and its main factors].

Selecting the principal environmental and cultivated factors from the main production areas of Angelica sinensis in Gansu, the problem of early bolting were analysed with grey system theory. After the quantitative analysis, the relational grade was: elevation > precipitaton > density of crop > organic fertilizer > phosphorus fertilizer > nitrogen fertilizer. The research would provide scientific basis for check on the rate of the early bolting of Angelica effectively as well as improve the product and benefits.

Altitude↗

PubMed1998

[Association between the debrisoquine hydroxylase gene polymorphism and the genetic susceptibility of Parkinson's disease].

OBJECTIVE: To clarify the relation of the debrisoquine hydroxylase gene polymorphism with the genetic susceptibility of Parkinson's disease. METHODS: The debrisoquine hydroxylase gene polymorphisms were analyzed with the polymerase chain reaction-restriction fragment length polymorphism methods in 100 cases of Parkinson's disease and 100 age-,sex-matched normal controls. RESULTS: It was found that the frequencies of A and B mutation of debrisoquine hydroxylase gene in group of patients were higher than those in the controls, and the risk of suffering Parkinson's disease increased 2 times. In group of the patients, the frequencies of C188-->T, G4268-->C and C2938-->T were also higher than those in the controls. Especially in those with C2938-->T mutation, the risk of suffering the disease increased 2.58 times. CONCLUSION: The result suggested that the defect of the detoxifying enzymes might be a factor contributing to the genetic susceptibility of Parkinson's disease.

Adult↗

PubMed1998

Comparison of carcinoembryonic antigen promoter regions isolated from human colorectal carcinoma and normal adjacent mucosa to induce strong tumor-selective gene expression.

To establish in vivo gene therapy against cancer, it is requisite to induce strong, cancer cell-selective expression of a therapeutic gene. Comparison of the promoter activity of 5' flanking regions of the carcinoembryonic antigen (CEA) gene isolated from various origins is therefore of considerable interest. The 5' flanking region of the CEA gene between -135 and +69 bp upstream from the transcriptional start site, which is recognized as the core promoter region, was isolated from CEA-producing human colorectal carcinoma (CRC), normal adjacent mucosa, CEA-producing cell lines and CEA-non-producing cell lines. No mutations were observed by single-strand conformation polymorphism in the CEA promoter regions. Subsequent sequence analysis revealed that there were no mutations in the CEA promoter regions isolated from CEA-producing CRC and normal adjacent mucosa. Furthermore, nuclear extracts prepared from CEA-producing human CRC cells could equally bind to both the CEA promoter fragments isolated from CEA-producing CRC and normal mucosa. Both CEA promoter regions could direct 5- to 20-fold higher expression of a luciferase reporter gene in CEA-producing cells than in CEA-non-producing cells. Therefore, we suggest that the use of either CEA promoter region isolated from CRC or normal mucosa is equally effective to induce strong, CEA-producing cancer-selective expression of a therapeutic gene.

Base Sequence↗

PubMed1998

Inhibition of a Mycobacterium tuberculosis beta-ketoacyl ACP synthase by isoniazid.

Although isoniazid (isonicotinic acid hydrazide, INH) is widely used for the treatment of tuberculosis, its molecular target has remained elusive. In response to INH treatment, saturated hexacosanoic acid (C26:0) accumulated on a 12-kilodalton acyl carrier protein (AcpM) that normally carried mycolic acid precursors as long as C50. A protein species purified from INH-treated Mycobacterium tuberculosis was shown to consist of a covalent complex of INH, AcpM, and a beta-ketoacyl acyl carrier protein synthase, KasA. Amino acid-altering mutations in the KasA protein were identified in INH-resistant patient isolates that lacked other mutations associated with resistance to this drug.

3-Oxoacyl-(Acyl-Carrier-Protein) Synthase↗

PubMed1998

[Detection of hemophilia A carriers by PCR analysis of hind III polymorphism in the factor VIII gene].

OBJECTIVE: To explore a scheme of using PCR analysis in the detection of carriers of Hind III polymorphism of factor VIII gene of hemophilia A. METHODS: Implicating intron 19 of the factor VIII gene of 6 patients with the hemophilia A and 207 unrelated X-chromosomes were amplified by PCR and were analysed by means of Amp-RFLPs of Hind III. RESULTS: The incidence of the polymorphic Hind III sites in the given population was found to be 0.29. The frequence of the Hind III heterozygotes in women calculated according to Hardy-Weinberg equation was 0.41, which proved to be informative enough for carrier detection and prenatal diagnosis of hemophilia A. 2 out of 6 families (33%)examined in this study were informative. CONCLUSION: The new scheme proved to be effective for hemophilia A carrier detection and prenatal diagnosis.

Deoxyribonuclease HindIII↗

PubMed1998

Hypervariability generated by natural selection in an extracellular complement-inhibiting protein of serotype M1 strains of group A Streptococcus.

In many countries, M1 strains of the human pathogenic bacterium group A Streptococcus are the most common serotype recovered from patients with invasive disease episodes. Strains of this serotype express an extracellular protein that inhibits complement [streptococcal inhibitor of complement (Sic)] and is therefore believed to be a virulence factor. Comparative sequence analysis of the 915-bp sic gene in 165 M1 organisms recovered from diverse localities and infection types identified 62 alleles. Inasmuch as multilocus enzyme electrophoresis and pulsed-field gel electrophoresis previously showed that most M1 organisms represent a distinct streptococcal clone, the extent of sic gene polymorphism was unexpected. The level of polymorphism greatly exceeds that recorded for all other genes examined in serotype M1 strains. All insertions and deletions are in frame, and virtually all nucleotide substitutions alter the amino acid sequence of the Sic protein. These molecular features indicate that structural change in Sic is mediated by natural selection. Study of 70 strains recovered from two temporally distinct epidemics of streptococcal infections in the former East Germany found little sharing of Sic variants among strains recovered in the different time periods. Taken together, the data indicate that sic is a uniquely variable gene and provide insight into a potential molecular mechanism contributing to fluctuations in streptococcal disease frequency and severity.

Antigens, Bacterial↗

PubMed1998

[Cytochrome P450*2D6 gene polymorphism in Chinese population].

OBJECTIVE: To demonstrate the cytochrome P450*2D6(CYP*2D6) gene polymorphism distribution in Chinese. METHODS: The polymorphisms of CYP*2D6 gene in 100 Chinese people were studied with polymerase chain reaction and Xba I restriction fragment length polymorphic (RFLP) techniques. RESULTS: The frequencies of CYP*2D6 gene A, B, D and E mutations were 1%, 6.5%, 0.5% and 1%, respectively; the genotypes of 29kb/29kb,44kb/29kb and 44kb/44kb Xba I RFLP were 38%, 46% and 13%, respectively. It was found that 12% of B mutations were linked with even though A and B mutations were mainly associated with 29kb/29kb genotype. CONCLUSION: The frequencies of the four kinds of CYP*2D6 gene mutation in Chinese were lower than those of the European, but the frequency of Xba I 44kb allele was a little higher.

Adult↗