Typhoid fever due to a Salmonella typhi strain of reduced susceptibility to fluoroquinolones

Objective: To report a case of typhoid fever contracted in Portugal in 1994 due to a Salmonella typhi isolate which had reduced susceptibility to fluoroquinolone (MIC 1 mg/L of ciprofloxacin) and high level resistance to nalidixic acid (MIC ≥56 mg/L).
Methods: Molecular studies of reduced susceptibility to fluoroquinolones comprised complementation tests with a wild-type allele and sequencing directly from PCR products of the gyrA gene.
Results: Complementation tests and DNA sequencing showed that a mutation occurred in the gyrA gene of this clinical isolate, resulting in a substitution of phenylalanine for serine at position 83 of GyrA.
Conclusions: Because quinolones may be regarded as a treatment of choice in typhoid fever, it seems important now to recommend cautious use of these drugs as first-line therapy and possibly use of nalidixic acid resistance as a marker for detection of 'first-step' resistance to fluoroquinolones in S. typhi.     

The roles of follicular envelopes in the initiation of Xenopus oocyte maturation

Gonadotropins and progesterone induce in vitro meiotic maturation of the follicleenclosed Xenopus laevis oocyte. The kinetics of maturation are identical for both hormones. The enzymatic removal of the follicular envelopes which suppresses gonadotropin activity does not modify the efficiency of progesterone (1 μM)-induced maturation. It was, however, shown that defolliculation decreases the kinetic of maturation: GVBD₅₀ (the time necessary to obtain 50% of germinal vesicle breakdown or maturation) was 8.08 ± 1.25 hr when follicles are induced to mature in the presence of progesterone and 4.30 ± 0.89 hr in the case of defolliculated oocytes. This result demonstrates that the follicular envelopes play a role in inhibition of steroid-induced maturation. When oocytes are defolliculated in the presence of aminogluthetimide, an inhibitor of steroid synthesis, the kinetic of oocyte maturation is also decreased (GVBD₅₀: 4.98 ± 1.75 hr) indicating that the biosynthesis of steroid at the level of follicular envelopes is not involved in the phenomenon.     

Cryptic genomic imbalances in de novo and inherited apparently balanced chromosomal rearrangements: Array CGH study of 47 unrelated cases

Investigations of apparently balanced chromosomal rearrangements in patients with abnormal phenotype by molecular cytogenetics tools, especially by array CGH, revealed a proportion of unsuspected imbalances. It was estimated recently that 40% of apparently balanced de novo translocations with abnormal phenotype were associated with cryptic deletion.We explored 47 unrelated mental retardation patients carrying an apparently balanced chromosomal rearrangement with high-resolution oligonucleotides arrays. We included 33 de novo cases (21 translocations, 7 inversions and 5 complex chromosomal rearrangements (CCR)) and 14 inherited cases (7 translocations, 5 inversions and 2 CCR).Twenty of the 47 cases (42.6%) carried a cryptic deletion ranging from 60 kb to 15.37 Mb. It concerned 16/33 de novo rearrangements (8/21 translocations, 4/7 inversions and 4/5 CCR) and 4/14 inherited rearrangements (1/7 translocations, 2/5 inversions and 1/2 CCR). The proportion of imbalances was not statistically different between de novo and inherited cases.Our results support that about 40% apparently balanced chromosomal rearrangements with abnormal phenotype are in fact imbalanced and that these rearrangements should be systematically investigated by array CGH independently of their de novo or inherited character.     

Predictors of pneumocystosis or tuberculosis in HIV-infected Asian patients with AFB smear-negative sputum pneumonia

OBJECTIVES: To identify predictors of Pneumocystis jiroveci pneumonia (PCP) or pulmonary tuberculosis (TB) in acid-fast bacillus smear-negative HIV-infected patients and to develop clinical prediction rules. DESIGN: A cohort study conducted in consecutive hospitalized Asian patients. METHODS: Multivariate analyses were performed on the Cambodian sample to determine clinical, radiological, and biological predictors of PCP or TB at hospital admission. The Vietnamese sample was kept for independent validation. RESULTS: In Cambodia, the gold standard technique for TB and PCP were fulfilled in 172 (27 cases) and 160 (84 cases) patients, respectively. For TB, independent predictors included the following: headache [odds ratio (OR) 3.0; 95% confidence interval (CI) 1.04 to 8.6], localized radiological opacity (OR 5.8; 95% CI 1.9-17.9), and mediastinal adenopathy (OR 10.1; 95% CI 3.5 to 29.0); and for PCP: resting oxygen saturation <90% (OR 3.3; 95% CI 1.3 to 8.5 for resting arterial oxygen saturation >or=80%; and OR 9.1; 95% CI 1.8 to 44.5 for resting arterial oxygen saturation <80%), trimethoprim-sulphamethoxazole prophylaxis (OR 0.1; 95% CI 0.04 to 0.6), and diffuse radiological shadowing (OR 7.0; 95% CI 2.7 to 18.6). PCP risk predicted by a score based on these 3 factors ranged from 3% to 92% (Cambodia). When tested on Vietnamese patients (n = 69, 38 with PCP), the score maintained correct predictive ability (c-index = 0.72) but with poor calibration. CONCLUSIONS: The PCP score could provide a useful clinical tool to identify PCP among acid-fast bacillus smear-negative pneumonia and start specific therapy.     

Vacuolating megalencephalic leukoencephalopathy with subcortical cysts: functional studies of novel variants in MLC1

Nine new unrelated patients presenting vacuolating myelinopathy with subcortical cysts were identified and analyzed for variations in the MLC1 gene. We detected 12 mutations (p.Leu37fs, p.Met80Val, p.Leu83Phe, p.Pro92Ser, p.Ser93Leu, p.Ile108fs, p.Gly130Arg, p.Cys171fs, p.Glu202Lys, p.Ser269Tyr, p.Ala275Asn, and p.Leu310_311insLeu) of which nine were novel. In one patient we did not detect mutations. Using a heterologous system, three new missense variants (p.Glu202Lys, p.Ser269Tyr, and p.Ala275Asn) and a single leucine insertion (p.Leu310insLeu)--lying in a stretch of seven leucines--were functionally assayed by determining total protein levels and mutant protein expression at the plasma membrane. No correlation was observed between mutation, clinical features, and plasma membrane expression of mutant protein.     

Combined antithrombin and protein C supplementation in meningococcal purpura fulminans: a pharmacokinetic study

PURPOSE: To document in patients with meningococcal purpura fulminans (PF), the effects of a combined supplementation with antithrombin (AT) and protein C (PC) plasma concentrates and to estimate the pharmacokinetics and dose requirements of each inhibitor. DESIGN: Retrospective study of 15 patients. SETTING. One paediatric and one adult ICU in a university hospital. INTERVENTIONS: In addition to standard intensive care, all patients received a 100 IU/kg loading dose of AT and PC concentrates, followed by a continuous infusion (AT: 100-150 IU.kg.day; PC: 100 IU.kg.day in adults, and 400 IU/kg in infants). MEASUREMENTS: Clinical data, coagulation, and fibrinolysis parameters, AT and PC activities, and free protein S (PS) levels were sequentially measured. Restitution ratio, median increment after supplementation, and half-life of clearance from plasma were calculated for the two plasma substitutes. RESULTS. At admission, all patients had a severe decrease in AT, PC, and PS levels. The supplementation regimen induced a substantial increase in AT and PC activities, peaking at H18 and H48, respectively. The supplementation procedure did not modify free PS levels. The median values of AT and PC restitution ratio, increment in plasma activity observed after 100 IU/kg concentrate, and apparent half-life of clearance from plasma were 0.85 U.ml.U.kg and 0.59 U.ml.U.kg, 23% and 21%, 16 h and 6 h, respectively. CONCLUSION: If AT and PC concentrates are to be given in fulminant meningococcemia, the doses of supplementation should be at least 150 IU/kg AT and 250 IU/kg PC as loading dose and 150 IU/kg AT and 200 IU/kg PC as daily maintenance therapy. Taking into account the individual variability in inhibitor deficiency and restitution ratio, repeated measurements of plasma levels are mandatory to obtain a patient-based adjustment of the supplementation.     

Reconstruction of a full-thickness collagen-based human oral mucosal equivalent

Tissue engineered human oral mucosa has the potential to be applied to the closure of surgical wounds after tissue deficits due to facial trauma, malignant lesion surgery or preposthetic procedure. It can also be used to elucidate the biology and pathology of oral mucosa and as a model alternative to animals for safety testing of oral care products. Using the technology previously developed in our laboratory for the production of a skin equivalent, we were able to reconstruct a nonkeratinized full-thickness human oral mucosal equivalent closely mimicking human native oral mucosa. The successive coculture of human lamina propria fibroblasts and human oral epithelial cells isolated from the nonkeratinized region of oral cavity in a porous collagen–glycosaminoglycan (GAG)–chitosan scaffold gave rise to a lamina propria equivalent (LPE) and then to an oral mucosa equivalent (OME). The results of the histology, immunohistology and transmission electron microscopy of this OME demonstrated the presence of a nonkeratinized pluristratified and differentiated epithelium as in native nonkeratinized human oral mucosa expressing both K13 and K3/76. This epithelium was firmly anchored to the LPE by a continuous and ultrastructurally well-organized basement membrane. In the LPE, fibroblasts synthesized new extracellular matrix where the average collagen fibre diameter was 28.4 nm, close to that of native oral mucosa. The proliferative capacity of the basal cells was demonstrated by the expression of Ki67.     

The human lumbar anterior epidural space: morphological comparison in adult and fetal specimens

To increase our understanding of the clinical anatomy of the epidural space, the human lumbar anterior epidural space was studied morphologically and developmentally. Histological transverse sections of human lumbar spines were taken at the level of the intervertebral disc and the vertebral body in adult specimens and in fetuses aged 13, 15, 21, 32 and 39 weeks (menstrual age). At 13 weeks, connective tissue filled the epidural space. The dura mater was attached anteriorly to the posterior longitudinal ligament (PLL). The PLL was attached to the vertebral body beside the midline, whereas it adhered to the posterior edge of intervertebral disc. The anterior internal vertebral venous plexus was located anterolaterally and anteromedially. The vertebral canal was lined with connective tissue that differentiated in a periosteum in contact with the ossification centers. At 15 weeks, the PLL was composed of deep and superficial layers. At 21 weeks, the attachment between the dura mater and PLL was ligament-like at the level of the vertebral body. At 32 weeks, the dura mater was adherent to the superficial layer of PLL. At 39 weeks, groups of adipocytes were identified, and the dura mater was attached to the PLL by some ligaments. There were many more similarities between the adult and the 39-week fetus. In conclusion, some differences in the anatomy of the epidural space exist at each fetal stage studied. The structures of the epidural space are already formed in the fetus of 13 weeks, but they differentiate progressively within the connective tissue.