早期钩体病患者血清钩体DNA聚合酶链反应和地高辛—硷性磷酸酶发光体探针杂交分析

作者从已建立的问号钩体基因文库中筛选合成一对引物G_1G_2,中国四川14份早期钩体病患者血清中的DNA经硫酸氰胍、二氧化硅和蛋白酶K纯化后,在G_1G_2引导下行聚合酶链反应(PCB),并以地高辛标记的同源探针行DNA印迹杂交,全部血清样品均获得确切地阳性结果。用地高辛—硷性磷酸酶发光体标记PCR扩增的同源DNA探针,与16株Yasuda基因组钩体作DNA印迹分析,其中8株存在同源单拷贝序列,它们皆为我国常见和流行的优势致病菌株,本研究结果表明:引物G_1G_2可用于四川钩体PCR检测和分析,PCR常规结合同源DNA探针杂交识别,能提高其敏感性和可靠性;地高辛—硷性磷酸酶发光体配合PCR等方法,可使微量DNA的检测和分析更趋完善。同时,本研究还提供了有价值的钩体DNA同源序列资料。     

Genetic amniocentesis: a risk factor for preterm delivery?

Objective: To determine whether genetic amniocentesis performed in the second trimester of pregnancy is associated with the risk of preterm delivery. Study design: Case–control study performed in several departments of obstetrics and gynaecology of nine European countries. Three thousand and ninety-one preterm births and 5298 controls randomly selected from singleton births born at term during 1994–1997 were analysed. Logistic regression models were used to compare preterm births altogether and, separately, spontaneous preterm delivery and induced preterm delivery. Results: An increased risk of preterm delivery was found in women having second trimester genetic amniocentesis after taking account of other risk factors and confounding variables (odds ratios (OR)=1.59, 95% confidence intervals (95% CI): 1.31–1.92). The association was statistically significant and similar for spontaneous preterm delivery and induced preterm delivery. Conclusion: The study shows an association between preterm delivery and genetic amniocentesis. In view of the wide use of amniocentesis, further research on the etiologic role of this prenatal diagnostic technique is needed.     

The uptake of recombinant Factor VIII in the Netherlands

In comparison with other biotechnology substitutions, the adoption of recombinant Factor VIII (rFVIII) has been relatively slow. We sent a postal questionnaire to all Dutch haemophilia patients and haemophilia-treating physicians, to determine which factors predict whether a patient uses plasma-derived FVIII (pdFVIII) or rFVIII and to investigate patients' and doctors' opinions on both products. Fifty-six per cent of patients received rFVIII. This percentage varied widely between centres. Only one doctor would choose to use pdFVIII if he suffered from haemophilia A himself, and 74% would choose to use rFVIII. Younger patients, those not infected with the human immunodeficiency virus or hepatitis C, and those who did not have family members who used pdFVIII switched more often from pdFVIII to rFVIII. Patients who rated themselves as innovative, who had family members who used rFVIII, and those who were treated in a large haemophilia treatment centre were also more likely to have switched. For physicians and patients alike, the respondents generally did not see large differences between rFVIII and pdFVIII, except for the risk of infections and the knowledge of long-term effects (both larger for pdFVIII). Although haemophilia patients represent one of the most empowered patient groups, physicians appear to have been influential in choosing between pdFVIII and rFVIII.     

Treatment of chronic hepatitis B virus infection - Dutch national guidelines

The development of this guideline was initiated and coordinated by the Netherlands Association of Gastroenterologists and Hepatologists (Nederlandse Vereniging van Maag-Darm-Leverartsen). The aim is the establishment of national standards in the evaluation and antiviral treatment of patients with chronic hepatitis B virus (HBV) infection. This includes recommendations on the initial evaluation of patients, choice and duration of antiviral therapy, follow-up after antiviral therapy and monitoring of patients not currently requiring antiviral therapy. The initial evaluation of chronic HBV-infected patients should include testing of liver biochemistry, virus serology and abdominal imaging. In patients without cirrhosis, antiviral treatment is recommended for those with a serum HBV DNA of at least 1.0 x 105 c/ml (>or=2.0 x 10(4) IU/ml) in combination with: a) elevation of serum alanine aminotransferase (ALAT) level above twice the upper limit of normal during at least three months, and/or b) histological evidence of porto-portal septa or interface hepatitis on liver histology. In patients with cirrhosis, antiviral treatment is recommended if serum HBV DNA is 1.0 x 10(4)c/ml (>or=2.0 x 10(3) IU/ml) or higher, independent of ALAT levels or histological findings. If the patient has decompensated cirrhosis, antiviral treatment is recommended if serum HBV DNA is 1000 c/ml (>or=200 IU/ml) or higher. Patients who do not have an indication for antiviral treatment should be monitored because there is a risk of (re)activation of disease activity. Monitoring every three to six months is recommended for HBeAg-positive and HBeAg-negative patients with high viraemia (HBV DNA >or=1.0 x 10(5) c/ml or >or=2.0 x 10(4) IU/ml) and normal ALAT levels. For patients with serum HBV DNA below 1.0 x 10(5) c/ml (<2.0 x 10(4) IU/ml) the recommended frequency of monitoring is every three to six months for HBeAg-positive patients and every six to 12 months for HBeAg-negative patients. Peginterferon (PEG-IF N) therapy should be considered as initial therapy in both HBeAg-positive and HBeAg-negative patients without contraindications for treatment with this drug because of the higher chance of achieving sustained response compared with nucleos(t)ide analogue therapy. In patients starting nucleos(t)ide analogue therapy, the use of lamivudine is not preferred if long-term antiviral treatment is expected due to the high risk of antiviral resistance against this drug. Of the currently licensed nucleos(t)ide analogues, entecavir has the lowest risk of antiviral resistance (compared with lamivudine, adefovir and telbivudine), while suppression of viral replication seems most profound with either entecavir or telbivudine. The recommended duration of treatment with PEG-IF N is one year for both HBeAg-positive and HBeAg-negative patients. In HBeAg-positive patents, nucleos(t)ide analogue therapy should at least be continued until HBeAg seroconversion and a decline in HBV DNA to below 400 c/ml (80 IU/ml) has been achieved and maintained for six months during therapy. Whether nucleos(t)ide analogue therapy can be safely discontinued in HBeAg-negative patients is unknown; usually prolonged or indefinite antiviral treatment is necessary. Patients receiving PEG-IF N should be monitored once a month, while three monthly monitoring suffices for those receiving nucleos(t)ide analogues. Genotypic analysis of the HBV polymerase is indicated if an increase in serum HBV DNA of at least 1 log(10) c/ml (IU/ml) compared with the nadir value is observed during nucleos(t)ide analogue therapy. Antiviral therapy should be changed as soon as possible in case of confirmed genotypic resistance. Adding a second antiviral agent seems beneficial over switching to another agent. With the availability of multiple new antiviral drugs for the treatment of chronic hepatitis B, effective treatment is now possible for more patients and for longer periods. However, the complexity of HBV therapy has also increased. Nowadays, virtually all chronic HBV-infected patients can be effectively managed, either by inducing sustained off-treatment response or by maintaining an on-treatment response.     

Results of an enhanced-outreach programme of hepatitis B vaccination in the Netherlands (1998-2000) among men who have sex with men,hard drug users,sex workers and heterosexual persons with multiple partners

BACKGROUND/AIMS: The Dutch Ministry of Health funded a pilot vaccination project targeting groups at high risk for sex- and drug-related hepatitis B transmission. METHODS: In seven Municipal Health Service (MHS) areas, three-part hepatitis B vaccination was offered free to men who have sex with men (MSM), drug users (DUs), and heterosexuals with multiple partners, including sex workers (SWs). Four intervention areas recruited participants through care-givers and opinion leaders and offered vaccination at non-MHS sites. Three control areas only used flyers to offer vaccination at MHS during regular hours. RESULTS: Over 18 months, 13808 persons enrolled for the first vaccination, representing 63% of the targeted population in the intervention areas and 23% in control areas. In intervention areas, only 19% of DUs enrolled, versus 4% in control areas. In both areas, enrollment of the targeted heterosexual population (64%) was satisfactory. MSM were most compliant in having the full series. Of vaccination sources, general practitioners (GPs) attained highest compliance (71%, odds ratio 1.82). CONCLUSIONS: Dutch MHS facilities can reach high-risk individuals, but DUs require additional outreach. Vaccine coverage was disappointing, but our experience will be deployed nationwide and successful strategies might be employed elsewhere in countries of low endemicity.