Prevalence of antibody to Toxoplasma gondii in black-headed gulls (Chroicocephalus ridibundus), Dianchi Lake, China.

Sera from 659 Black-headed Gulls (Chroicocephalus ridibundus) in Dianchi Lake, China were assayed for Toxoplasma gondii antibodies using the modified agglutination test (MAT). Specific T. gondii antibodies were detected in 131 (19.9%) Black-headed Gulls (MAT titer ≥ 1 ∶ 5). These results indicate that T. gondii infection is common in Black-headed Gulls.

[Mechanism of the formation of a special inv(Y): a case study].

We report for the first time in China, the characterization of a special abnormal inv(Y) with dual-color fluorescence in situ hybridization (D-FISH). We also study the mechanism of the formation of chromosome Y inversion and its relationship with the phenotype of recurrent spontaneous abortion. Using biotin-11-dUTP-labeled Yp11.3 breakpoint probe (No. 889) and CY3-labeled Yq12 heterochromatic region DNA probe (PY3.4), we performed D-FISH on a balanced translocation carrier with a [46, XY(90%)/46, X, inv(Y)(p11.3; q12)] karyotype determined by G-banding karyotyping, whose wife had recurrent miscarriages. The result of D-FISH shows that the percentage of cells with abnormal karyotypes is about 22%, higher than that determined by G-banding analysis. Moreover, besides the type of inversion diagnosed by G-banding, there are the two other abnormal karyotypes, including a type of chromatid inversion, which is difficult to be detected by conventional G-banding technique. The present of the three types of inversion confirms that the breakpoints of inv(Y) are heterogeneous. D-FISH is a powerful tool for the detection of chromosomal inversion due to its sensitivity and specificity.

[The application of interphase fluorescence in situ hybridization to the diagnosis of X chromosomal count abnormality in ovarian carcinoma cell].

To study the technique of fluorescence in situ hybridization (FISH) and its application value in the diagnosis of sex chromosomal count abnormality in ovarian carcinoma cell. Biotin labeled alpha satellite X chromosome DNA(pBamX7) probe was hybridized with pre-treated slides of ovarian carcinoma cell interphase nucleus in 18 cases of ovarian carcinoma specimens. The slides were treated with Avidin-FITC and Anti-avidin, amplified with an additional layer and counter-stained with PI in antifade solution. The hybridization signals as well as interphase nucleus settings were observed with WIB filters under fluorescence microscope Olympus AX-70, and the number of interphase nucleus in the ovarian carcinoma cell was counted. It was observed under the microscope that the Biotin labeled pBamX7 probe showed green hybridization signals. Cytoplasm counter-stained with PI showed reddish orange. Increased chrosome X copy number was observed in 11/18(61%) ovarian carcinoma specimens, of which the rest 7 (39%) had no increase of chrosome X copy number. Gain of X chrosome had a certain incidence in ovarian cancers, which played a role in the recurrence and development of ovarian cancers. Its significance needs further investigation.

[Fluorescence in situ hybridization detection of peripheral lymphocyte and ultrastructural study of the testicular tissue in a 48,XXYY syndrome patient].

OBJECTIVE: To investigate the pathogenesis of male sterility in 48,XXYY syndrome patient. METHODS: The peripheral lymphocyte was detected by dual-color fluorescence in situ hybridization. The bioptic testicular tissues were pathologically sectioned and ultra-thin sections were examined by electron-microscopy. RESULTS: The pathological findings revealed extremely severe dysgenesis of the badly damaged testicular tissue. Only a few convoluted seminiferous tubules were found, in which no spermatogenic cell or sperm of any range could be viewed. The ultrastructural observations showed the thickened interstitial vascular walls of the testicular tissue and severe hyperplasia of the collagen fibers in the basilemma and lumens of the blood vessels. CONCLUSION: The structure of the testicle in the 48,XXYY syndrome patient has severe fibrous hyperplasia, leading to the non-specific thickening of the barrier and serious damage to the blood-testis barrier, which in turn produce significant disturbance and pathological changes in the process of the spermatogenic cell formation. The whole interrelated loops account mainly for the male sterility.

[The application of dual-color fluorescence in situ hybridization to the diagnosis of Klinefelter syndrome].

The objective of the work is to study the technique of dual-color fluorescence in situ hybridization(D-FISH) and its application value in the diagnosis of sex chromosomal count abnormality Klinefelter syndrome and establish an experimental approach to metaphase chromosome and interphase nucleus FISH technique. Biotin labeled alpha satellite X-chromosome DNA(pBamX7) probe and Digoxigenin labeled Y-chromosome long arm terminal repetitive sequence (pY3.4) probe were hybridized with pre-treated slides of peripheral blood chromosome and interphase nucleus in 19 cases of Klinefelter syndrome specimens. After being washed,the slides were treated with Avidin-FITC,Rhodamine-FITC and Anti-avidin,amplified with an additional layer and counter-stained with DAPI in an antifade solution. The hybridization signals,chromosomal or interphase nucleus settings were observed respectively with WIB, WIG and WU filters under fluorescence microscope Olympus AX-70,and the number of metaphase chromosome and interphase nucleus in the peripheral blood was counted. It was observed under the microscope that the Biotin labeled pBamX7 probe showed 2 green hybridization signals and that the Digoxigenin labeled pY3.4 probe showed 1 red hybridization signal. Chromosome or interphase nucleus counter-stained with DAPI showed blue. The average signal rate of chromosome and interphase nucleus hybridization was 95.89% and 95% respectively,significantly higher than the normal control (2.75%). Karyotype 47,XXY was confirmed,which agrees with the chromosomal findings. One case showed mosaic nuclei. XXY chromosome hybridization signal rate was 92% and XY hybridization signal rate was 6.7%, higher than the normal control rate of 4.17%. FISH is a valuable technique in diagnosing sex chromosomal count abnormality Klinefelter syndrome with the merits of fast speed, high sensitivity, strong signal,low background and multiple color. Therefore, FISH technique can find wide application and potential in prenatal diagnosis.