Biological changes of Enterococcus faecalis in the viable but nonculturable state.

Enterococcus faecalis may enter a viable but nonculturable (VBNC) state under adverse conditions. E. faecalis, the major bacterial species present in failed root canal treatments, is thought to survive after endodontic treatment by entering a VBNC state. In this study, we characterized the VBNC state of E. faecalis. We designed 3 different protocols to successfully induce the VBNC state. Approximately one-third of bacteria entered a VBNC state after 15-30 days, and all remained viable for at least 2 months. The morphology, glycometabolism, and adhesion capabilities of VBNC cells differed from those of E. faecalis during the exponential growth phase. Specifically, VBNC E. faecalis cells could not decompose lactose, D-mannitol, or D-sorbitol, although they were able to metabolize sucrose. Transmission electron microscopy showed that the morphology of the VBNC E. faecalis cells changed significantly; the cytoplasmic matrix was unevenly condensed and the overall morphology of the cells became irregular, but the cell membranes remained intact. Although the adhesion ability of the bacteria decreased, VBNC E. faecalis could still adhere to collagen fiber type I and tooth dentine. The persistence of this adhesion ability may be important in the virulence of VBNC E. faecalis.

Inheritance of balanced translocation t(17; 22) from a Down syndrome mother to a phenotypically normal daughter.

We report that a 30-year-old woman with mental retardation was referred for prenatal diagnoses during pregnancy. An ultrasound scan showed that the heart structure and function of the fetus were normal. Cytogenetic analysis showed that the female karyotype was 47,XX, t(17; 22) (q21; q11), +21. The woman's husband had a normal male karyotype and was phenotypically normal. During this first pregnancy, an amniocentesis, which was done at 19 weeks, revealed that the fetal karyotype was 46,XX, t(17; 22) (q21; q11). Fluorescence in situ hybridization testing of amniotic fluid gave a normal result for chromosome 21. The child was a phenotypically normal female baby.

Sperm retrieval from patients with nonmosaic Klinefelter's syndrome by semen cytology examination.

Successful sperm retrieval from ejaculates of nonmosaic Klinefelter's syndrome (KS) patients by using semen cytology examination was described in this report. The clinical parameters of KS patients with sperm compared to patients without sperm were described. One hundred and fifty-one patients were proven to suffer from KS by chromosomal analysis using G-banding. Spermatozoa were obtained from 10 patients (10/151, 6.6%) using semen analysis. After semen cytology examination, 32 patients (32/151, 21.2%) were found to have sperm or germ cell in their ejaculate. The patients with successful sperm retrieval were significantly younger (27.1 ± 3.7 years) than the patients for whom sperm retrieval failed (28.9 ± 4.2 years). The mean serum testosterone level and the mean T/LH ratio of KS patients with successful sperm retrieval were significantly higher in men with sperm than in men without sperm (testosterone: 3.2 ± 2.1 ng/mL vs 2.7 ± 1.5 ng/mL; T/LH ratio: 0.2 ± 0.3 vs 0.1 ± 0.1). In conclusion, semen cytology examination should be performed to identify sperm and germ cells in the ejaculate of KS patients if no sperm can be detected by traditional semen analysis. The serum testosterone level and T/LH ratio revealed an association between impaired Leydig cell function and impaired spermatogenesis in KS males. KS patients should receive earlier diagnosis and treatment.