糖尿病并发弓形虫感染的初步研究

本文用ＩＨＡ、ＩＦＡ、Ｄｏｔ－ＥＬＩＳＡ三种血清学方法检测３２０例糖尿病病人血清的弓形虫抗体，阳性率分别是１０．３１％、１８．１３％和１９．０６％。均高于对照组（Ｐ＜０．００５），这是糖尿病患者并发弓形虫感染的首次报告。     

Perinatal dengue infection

We report a case of vertical transmission of dengue infection in an infant. The mother's was a term pregnancy with a history of chronic hypertension. She presented with high fever of 3 days duration 5 days prior to delivery. Her initial complete blood count showed platelet count of 64,000/mm3. Dengue hemorrhagic fever was diagnosed 2 days later and symptomatic treatment was given. During labor her platelets dropped to 11,000/mm3 and platelet concentrate was given. Cesarean section was performed due to prolonged second stage of labor. Her infant was normal at birth except for petechiae on the left thigh. The child's platelet count was 34,000/mm3 and low grade fever was detected on the first day. Clinical sepsis was suspected and antibiotic treatment was started and continued for 4 days until all the cultures came back as negative. Both mother and her baby made an uneventful recovery and were discharged 6 days after delivery with normal platelet counts. Maternal blood was positive for IgM antibody to dengue virus. Both cord blood and the baby's blood were positive for dengue virus serotype 2 by PCR.     

A prospective study of dengue infections in Bangkok

Dengue infections were prospectively studied among 4- to 16-year-old students at a Bangkok school. Blood samples were obtained from 1,757 students in June 1980, before the dengue season, and in January 1981, after the season, and tested for dengue antibodies by the hemagglutination inhibition method. Classrooms were monitored daily for school absences. Fifty percent of the children had antibodies to, and were presumably immune to, at least 1 dengue serotype by the age of 7 years. Most (90/103, 87%) students who became infected by dengue viruses during the study period were either asymptomatic or minimally symptomatic (absent only 1 day). Most (7/13, 53%) of the symptomatic dengue infections (absent with fever for greater than or equal to 2 days) were clinically recognized as cases of dengue hemorrhagic fever which required hospitalization. None of 47 primary dengue infections required hospitalization, whereas 7 of 56 secondary infections did (P = 0.012). Preexistent dengue immunity, as detected by conventional serologic techniques, was a significant (odds ratio greater than or equal to 6.5) risk factor for development of dengue hemorrhagic fever.     

Serodiagnosis of asymptomatic dengue infection

Dengue virus(DENV) is a mosquito-transmitted virus that is expanding across the world,The incidence of dengue infection,especially severe disease,has been increasing,DENV consist of 4 serotypes of single stranded RNA viruses(D1-D4) in the genus Flavivirus,family Flaviviridae,Majority of dengue infections are asymptomatic cases,which cause difficulty in disease control and are important in dengue surveillance,There is still no gold standard to diagnose asymptomatic dengue infection,Plaque reduction neutralization test(PRNT) has been developed for many purposes such as immunological study,clinical study,vaccine trial and is currently the most sensitive and specific method for serological surveillance,However,PRNT shows some degree of cross reaction among different dengue serotypes especially secondary dengue infection cases and to other flaviviruses,Moreover,various modification since the beginning make PRNT lack of inter-laboratory standardization which is an important issue,This paper discusses the important of asymptomatic dengue infection and its diagnostic method.     

Sequence analysis of E/NS1 gene junction of dengue virus type 2 isolated in Brunei

A preliminary study of dengue infection in Brunei between 2005 and 2006 showed that dengue 2 was the predominant serotype. A total of five DEN-2 isolates were isolated and maintained in the mosquito cell-line, albopictus C6/36. The sequence spanning the envelope and non-structural protein 1 (E/NS1) junction (positions 2311 to 2550) of the isolates were determined and analysed at the amino acid and nucleotide levels. Alignment of the 240 nucleotide sequences among the five isolates showed changes occurring at 7 positions (2.9%) of the region. All but one nucleotide substitution (position 2319, amino acid 742 V --> F) were found at the 3rd position of the codons and were silent mutations. Amino acid homology ranged from 98% to 100%. Sequence divergence of the Brunei isolates varied from 5% to 6.6% compared with dengue-2 prototype New Guinea C strain. Comparison of the Brunei DEN-2 isolates with sixty-five other strains placed them in a cluster containing Indonesian strains isolated in 1973, 1978 and 2004 and Malaysian strains isolated in 1996, 1998 and 1999 in genotype group IV.     

A preliminary study of the influence of HIV infection in the transmission of tuberculosis

The human immunodeficiency virus (HIV) epidemic has had a profound influence on the epidemiology of tuberculosis (TB). The potential for HIV-associated TB cases to transmit M. tuberculosis and to produce a secondary increase in TB morbidity is unknown. A cross-sectional study was carried out to compare the prevalence of M. tuberculosis infection among the household contacts of HIV-positive and HIV-negative pulmonary tuberculosis (PTB) patients. Records of tuberculin (Mantoux) tests administered during routine contact investigations at the Chest Clinic, Hospital Kota Bharu, from 1999 to 2000 were reviewed. The HIV status of the patients was based on the results of ELISA tests while information on household contacts was gathered during visits to their houses. Ninety-four contacts of 39 HIV-negative patients and 44 contacts of 17 cases of HIV-positive patients were included in this preliminary study. 30% (12/40) of the contacts of HIV-positive PTB had a positive tuberculin compared with 52.8% (47/ 94) of the contacts of HIV-negative patients [OR = 0.41, 95% Confidence interval (CI) 0.17 - 0.97; p = 0.016]. The difference was still significant after performing multivariate logistic regression analysis to adjust for variables associated with infectiousness of TB (adjusted OR = 0.24, 95% CI 0.07 - 0.87; p = 0.03). This study has shown that HIV-infected PTB patients are less infectious to their contacts than HIV-negative patients. The presence of MV in the community may not necessitate a change of the current policy of the management of contacts.     

Detection of specific IgM in dengue infection

A modification of the IgM-capture ELISA which can provide an early diagnosis for dengue infection is presented. The test is technically simple compared to HI and appears to be more sensitive. It has the advantage over HIT for the detection of specific IgM in that it is more sensitive and the reading of the result is not subjective. There is the possibility of the test being able to replace HI and HIT in the future.     

丙型肝炎病毒体外感染胎肝细胞的初步研究

目的：探索原代培养胎肝细胞对丙型肝炎病毒（HCV）的易感性,旨在建立较为稳定实用的细胞感染模型。方法：研究血清与培养肝细胞共同孵育6－8h后,收集不同时相点标本,用逆转录聚合酶链反应（RT－PCR）分别检测细胞内或上清液中正负链RNA,免疫组化检测细胞内HCV NS3,NS5特异性抗原的表达情况,以及原位杂交检测细胞内HCV负链RNA。结果：接种感染血清3d后,即可在细胞内或培养上清液中检出HCV正负链RNA,间断检出至感染后第17天,HCV NS3,NS5特异性抗原可在感染细胞内表达,阳性物质位于乐中,原位杂交法证实细胞内存在负链RNA,也位于胞浆中,结论：原代培养的胎肝细胞对HCV不但易感,而且稳定地支持HCV复制。     

Neonatal dengue infection: report of dengue fever in a 1-day-old infant

A male infant was admitted because of fever. He was born at 37-weeks' gestation. His mother had experienced acute febrile illness with headache and myalgia. Her illness persisted with onset of active labor pain on day 5, which prompted cesarean section; postoperatively, the hematocrit decreased, requiring transfusion. The infant was well until fever developed at 16 hours after birth. There were petichiae on his face and trunk and the liver was enlarged. Fever subsided on day 5 without evidence of plasma leakage or severe hemorrhage. He made an uneventful recovery after 8 days of illness. Leukopenia and thrombocytopenia were present in the mother and infant. Both were diagnosed as dengue fever. Dengue type 1 was recovered from the infant by polymerase chain reaction. The dengue enzyme-linked immunoassay showed secondary infection in the mother and primary infection in the infant. In dengue-endemic areas, clinicians should be alert to dengue fever/dengue hemorrhagic fever in pregnant women presenting with acute febrile illness, and be prepared for proper management.     

A glance at the von Willebrand factor in dengue virus infection

To identify the level of von Willebrand factor (vWF) in dengue infection, especially severe DHF, and correlate the increase in vWF with thrombocytopenia, children admitted with dengue fever/DHF were examined for hemoglobin, hematocrit, platelet, and vWF for three consecutive days. Anti-dengue IgM and IgG were determined. Correlations between vWF and thrombocytopenia were analyzed using multivariate analysis. Forty-one patients were eligible for the study; of whom almost three fourths had a secondary infection, as proved serologically. At the beginning of the study, a high level of vWF along with a low platelet count were seen, which seemed to fit the hypothesis that an increase in vWF in the serum will be followed by a decrease in platelets, as a result of the platelet aggregation process in the peripheral blood vessels, predisposed by the immune complex events in DHF. Observations for three consecutive days revealed significant changes of vWF levels (p = 0.000) as well as platelet counts (p = 0.002). However in the context of dengue infections, these changes did not correlate well (p = 0.988). Could there have been a significant correlation if cases were followed for a longer period of time? Being a part of a more comprehensive study, it appeared that in patients with dengue infections, vWF and platelets were not the only factors involved in bleeding, indicating that activation of endothelium is one factor in a multifactorial process.     

Animal models of dengue virus infection

The development of animal models of dengue virus (DENV) infection and disease has been challenging, as epidemic DENV does not naturally infect non-human species. Non-human primates (NHPs) can sustain viral replication in relevant cell types and develop a robust immune response, but they do not develop overt disease. In contrast, certain immunodeficient mouse models infected with mouse-adapted DENV strains show signs of severe disease similar to the 'vascular-leak' syndrome seen in severe dengue in humans. Humanized mouse models can sustain DENV replication and show some signs of disease, but further development is needed to validate the immune response. Classically, immunocompetent mice infected with DENV do not manifest disease or else develop paralysis when inoculated intracranially; however, a new model using high doses of DENV has recently been shown to develop hemorrhagic signs after infection. Overall, each model has its advantages and disadvantages and is differentially suited for studies of dengue pathogenesis and immunopathogenesis and/or pre-clinical testing of antiviral drugs and vaccines.