Abortive potency of Chlamydophila abortus in pregnant mice is not directly correlated with placental and fetal colonization levels

Abortion, placental and fetal colonization, and levels of gamma interferon were analyzed for four Chlamydophila abortus strains presenting antigenic variations in a mouse model. Expression of virulence of these strains varied and indicated that abortion was not directly related to the number of bacteria in the placenta, and thus, other factors may have an important role in activating the abortion process.     

Identification of a novel frameshift mutation in the DFNB31/WHRN gene in a Tunisian consanguineous family with hereditary non-syndromic recessive hearing loss

Approximately 80% of hereditary hearing loss is non-syndromic. Non-syndromic deafness is the most genetically heterogeneous trait. The most common and severe form of hereditary hearing impairment is autosomal recessive non-syndromic hearing loss (ARNSHL), accounting for approximately 80% of cases of genetic deafness. To date, 22 genes implicated in ARNSHL have been identified. Recently a gene, DFNB31/WHRN, which encodes a putative PDZ scaffold protein called whirlin, was found to be responsible for the ARNSHL DFNB31. We found evidence for linkage to the DFNB31locus in a consanguineous Tunisian family segregating congenital profound ARNSHL. Mutation screening of DFNB31/WHRNrevealed four nonpathogenic sequence variants and a novel frameshift mutation [c.2423delG] + [c.2423delG] that changed the reading frame and induced a novel stop codon at amino acid 818 ([p.Gly808AspfsX11] + [p.Gly808AspfsX11]). To determine the contribution of the DFNB31locus in the childhood deafness, we performed linkage analysis in 62 unrelated informative families affected with ARNSHL. No linkage was found to this locus. From this study, we concluded that DFNB31/WHRN is most likely to be a rare cause of ARNSHL in the Tunisian population.     

CT对腮腺肿瘤的诊断价值

目的：评价ＣＴ在腺肿瘤中诊断及鉴别诊断的价值。方法：通过回顾性分析４２例经术后病理证实的腮腺肿瘤的ＣＴ表现及其术前诊断,并与病理诊断进行对照分析。结果：２７例良性肿瘤中,有２４例ＣＴ表现为类圆形肿块,边界清楚,密度均匀,有３例密度欠均匀,边界模糊;１５例恶性肿瘤中,１２例ＣＴ为边界不清,密度不均匀,３例密度均匀,边界较清晰。术前ＣＴ诊断对８５．７１％腮腺肿瘤可作出定性诊断,但对其组织类型不能确认。     

Lesch Nyhan syndrome: A novel complex mutation in a Tunisian child

Lesch Nyhan syndrome (LNS) is an X-linked recessive disorder due to complete deficiency of the hypoxanthine–guanine phosphoribosyltransferase (HPRT) enzyme. Defect of the enzymatic activity is related to mutations of the HPRT1 gene. The disorder severity is due to neurological features and renal complications. Up to now, more than 300 mutations have been reported. We report on a Tunisian child with a severe phenotype due to a novel identified complex mutation.     

Cooccurrence of Multiple AmpC β-Lactamases in Escherichia coli,Klebsiella pneumoniae,and Proteus mirabilis in Tunisia

Over a period of 40 months, plasmid-mediated AmpC β-lactamases were detected in Tunis, Tunisia, in 78 isolates (0.59%) of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. In 67 isolates, only one ampC gene was detected, i.e., bla_CMY-2-type (n = 33), bla_ACC (n = 23), bla_DHA (n = 6) or bla_EBC (n = 5). Multiple ampC genes were detected in 11 isolates, with the following distribution: bla_MOX-2, bla_FOX-3, and bla_CMY-4/16 (n = 6), bla_FOX-3 and bla_MOX-2 (n = 3), and bla_CMY-4 and bla_MOX-2 (n = 2). A great variety of plasmids carrying these genes was found, independently of the species and the bla gene. If the genetic context of bla_CMY-2-type is variable, that of bla_MOX-2, reported in part previously, is unique and that of bla_FOX-3 is unique and new.     

Effects of metoprolol,methyldopa, and nifedipine on endothelial progenitor cells in patients with gestational hypertension and preeclampsia

Endothelial progenitor cells (EPCs) are critical for vascular regeneration and function, but are reduced in hypertensive disorders of pregnancy. We aimed to determine the possible effects of antihypertensive drugs, such as metoprolol, methyldopa, and nifedipine, on EPC number and functions in patients with gestational hypertension and preeclampsia. We collected blood samples from 30 normal pregnant women, 67 patients with gestational hypertension and 48 patients with preeclampsia. The patients received no drug or an antihypertensive drug, such as metoprolol, methyldopa, or nifedipine, between 20 and 24 weeks of gestation. The number of EPCs and circulating endothelial cells (CECs) in the blood was measured by flow cytometry. Moreover, colony formation and migration assays were performed on the isolated EPCs. Both the systolic and diastolic blood pressure (BP) increased, while the percentage of flow‐mediated vasodilatation (FMD) decreased in patients with gestational hypertension and preeclampsia, compared to the healthy controls at 20 weeks of gestation. CEC number increased in the patients, whereas EPC counts decreased. Furthermore, EPC colony formation and migration abilities were also impaired in the patients. However, administration of metoprolol, methyldopa, or nifedipine effectively restored the systolic and diastolic BP, FMD%, EPCs, and CEC numbers, as well as EPC migration capacity. Endothelial progenitor cells colony formation ability selectively improved with methyldopa and nifedipine. In patients receiving no drugs, most of these indexes worsened within 4 weeks (study duration). This study revealed a new pharmacological action of these antihypertensive drugs against gestational hypertension and preeclampsia, thus supporting their clinical use.     

体外定向诱导胚胎干细胞分化为内皮细胞及其与脐静脉内皮细胞的比较

目的：研究干细胞定向分化为内皮细胞的效率,并与人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)比较。方法：用两步法诱导干细胞HUES9分化为内皮细胞,前3 d在N2B27培养基中加入骨形态发生蛋白4 (25 ng/mL)和肝糖原合成激酶3β受体的选择性抑制剂CHIR99021(10 μmol/L)使细胞分化到中胚层状态,第4天开始用 VEGF165(200 ng/mL)和Forskolin(2 μmol/L)将细胞诱导为内皮细胞。观察分化第6天细胞形态,并与HUVECs比较。用 CD144作为内皮细胞表面标志物,流式细胞术检测分化效率及分化后细胞的身份。比较两种内皮细胞迁移和成管能 力。结果：分化后的内皮细胞与HUVECs在显微镜下形态一致。分化细胞表面标志物阳性率达到73.4%,重新培养后 的内皮细胞表面CD144阳性率达到86.6%,HUVECs为94.4%。分化后的内皮细胞与HUVECs均具有良好的迁移和成管 能力,但分化后的内皮细胞能力不如HUVECs强。运用SB431542后,能够提高分化后内皮细胞的迁移和成管能力。 结论：此两步法将干细胞分化为内皮细胞有较高的分化效率,可作为理想的分化方法。     

Distribution of HLA-B27 and its alleles in patients with reactive arthritis and with ankylosing spondylitis in Tunisia

The purpose of the present study is to investigate the frequency of HLA-B27 and its alleles in reactive arthritis (ReA) and in ankylosing spondylitis (AS) in Tunisia. HLA-B27 alleles were typed by PCR amplification with sequence-specific primers. We studied 17 patients with ReA associated with urethritis or with gastrointestinal infection; 42 HLA-B27-positive patients with AS and 100 healthy controls. Eleven ReA patients (67.7%) were HLA-B27 positive. There was an increased frequencies of HLA-B27 (P = 7.76 × 10⁻¹², OR = 59.30) and a moderate increase of HLA-B51 (P = 0.015; OR = 4.91) alleles in ReA patients when compared with healthy controls. Four B27 subtypes were identified: B*2702, 05, 09 and B*2712. The distribution of these alleles in the ReA patients was 37.5% for B*2702 and B*2705. Only these two subtypes were detected in 18 (42.8%) and 24 (57.1%), respectively, of the AS patients. B*2709 and B*2712 were relatively rare in ReA patients and were identified in one case each. Our results showed a restricted number of HLA-B27 subtypes associated with ReA and AS. B*2702 and 2705 were common in ReA and AS patients.     

Epidemiologic profile of Haemophilus influenzae infection in Tunisia

Haemophilus influenzae, a commensal bacteria, is frequently incriminated in broncho--pulmonary surinfections and severe diseases as meningitis, pneumonia and septic arthritis, particularly in young children. A multicenter study was conducted to establish the epidemiological profile of Haemophilus influenzae diseases, to determine the rate of antibiotics resistance for guide therapeutic and preventive strategies. The identification was based on the requirements for X and V factors, and the serotype b determined by agglutination. The betalactamase production was done by nitrocefin test. Antimicrobial susceptibility testing was determined on Muller Hinton chocolate agar with isovitalex. During the two year period, (January 1998 December 1999), 192 isolates of H. Influenzae were collected, 61% were recovered from invasive infections (44 meningitis, 8 bacteremia, 2 arthritis). The serotype b was identified in 55.7% of cases, 67.3% were invasive strains. 24.5% of isolates were producing betalactamase particularly invasive serotype b strains. All isolates of H. influenzae were susceptible to cefotaxim and to ofloxacin. Resistance rates to other antibiotics were: erythromycin 56.2%, tetracyclin 10.3%, rifampin 12%, chloramphénicol 1%, cotrimoxazole 16.5%, 11.5% amikacin and 20% gentamicin. The incidence of meningitis remained frequent in our country, involving the introduction of the vaccination in official calendar. Nevertheless, the surveillance of H. influenzae invasives infections and the serotyping of isolates were necessary to evaluate the impact of the immunization.