In vitro culture conditions favoring selection of chromosomal abnormalities in human ES cells.

Previous studies in several laboratories have demonstrated inadvertent chromosomal abnormalities in long-term cultured human embryonic stem cells (HESC). Here, using a two-step selection process we report a functional adaptation of a HESC line, HS181, towards a decreased dependence of extra cellular matrix (ECM) for in vitro survival, that is for growth directly onto a plastic surface. Successful adaptation was paralleled with a karyotype change in 100% of the cells to 47,XX,del(7)(q11.2),+i(12)(p10). The resulting adapted population showed increased survival and growth on plastic and also maintained expression of HESC markers, but showed a decreased pluripotency, as demonstrated by results from embryoid body (EB) formation in vitro. The finding of reduced pluripotency may not be totally unexpected since the variant cells were selected for self-renewal and proliferation, not differentiation during the adaptation to growth on plastic. In the light of recent models of a germ cell origin of HESC it is of particular interest that similar to many of the reported spontaneous HESC mutants, one of the identified specific chromosome abnormalities, i(12p), has also been strongly implicated for human germ cell cancer. However, the mutated HESC variant carrying this mutation failed to grow as a xeno-graft in a mouse model in vivo. This is surprising and needs a further mechanistic analysis for its explanation. Increased knowledge of genetic integrity of HESC may have significance on the understanding of mechanisms for tumor progression and thus strategy for treatments, particularly for tumors occurring in early life.

High co-prevalence of genogroup 1 TT virus and human papillomavirus is associated with poor clinical outcome of laryngeal carcinoma.

BACKGROUND: The aetiology and factors leading to the progression of laryngeal cancer are still unclear. Although human papillomavirus (HPV) has been suggested to play a role, reports concerning the effect of HPV infection on tumour development are controversial. Recently, transfusion transmitted virus (TTV) was suggested to play a role in certain infections as a causative or coinfecting agent. AIMS: To investigate whether the development and progression of laryngeal squamous cell carcinoma is associated with coinfection with TTV and HPV. METHODS: The prevalence of TTV and HPV was investigated using the polymerase chain reaction in tissue samples from 40 healthy individuals, 10 patients with recurrent papillomatosis, five patients with papillomatosis with malignant transformation, and 25 patients with laryngeal carcinoma. The obtained prevalence data were compared and analysed statistically. RESULTS: In the 11 patients with carcinoma who had metastasis or relapse there was a high rate of coinfection with genogroup 1 TTV and HPV (eight of 11), whereas in the 14 without tumour progression no coinfection was found. Coinfection was associated with significantly lower tumour free survival in patients with carcinoma (p < 0.001). Furthermore, four of five patients who had papillomatosis with malignant transformation were coinfected with genogroup 1 TTV and HPV. CONCLUSIONS: Although the nature of cooperation between HPV and TTV needs to be investigated further, coinfection with genogroup 1 TTV and HPV appears to be associated with poor clinical outcome in laryngeal cancer.

Persisting TT virus (TTV) genogroup 1 variants in renal transplant recipients.

TT virus (TTV) genogroup 1 infection has an increased prevalence in solid organ transplant recipients. In this study, the presence of TTV in renal transplant recipients was examined by two PCR methods, one capable of detecting most TTV genotypes (UTR-PCR), the other specific to genogroup 1 (N22-PCR). The N22-PCR detected TTV in 57% (53/92) of the renal transplant patients and in 20% (13/66) of the healthy individuals, while the prevalence of TTV with the UTR-PCR was above 90% in both the control and the patient groups. The N22-PCR was used in longitudinal studies of 31 renal transplant recipients, these PCR products were sequenced and aligned. TTV status was not associated with the patients' age at transplantation, male to female ratio and the time lag between kidney transplantation and the TTV test. During the follow-up consistent TTV status was found in 26 patients, while two initially TTV positive patients converted to negative and three initially negative patients converted to positive. The TTV variants varied among the tested patients, but were the same in the consecutive samples of each patient, indicating that TTV infection was persistent in renal transplant recipients and novel infection occurred rarely in the post-transplant period.

Human cytomegalovirus load in the peripheral blood determined by quantitative competitive polymerase chain reaction.

Primary human cytomegalovirus infection and the viral reactivation from latency are major complications in organ transplant recipients. In the peripheral blood the replicating virus can be detected either by nucleic acid based tests or by demonstrating the HCMV structural proteins in antigenemia test. We developed a quantitative competitive PCR method to assess the HCMV load in the peripheral blood. The viral load in nine healthy blood donors and in four renal transplant recipients with negative antigenemia test was in the same range: 5-124 (median: 18) HCMV copies/10(6) beta-globin copies for healthy blood donors and 16-48 (median: 37) HCMV copies/10(6) beta-globin copies for the transplant recipients. Three antigenemia positive renal transplant recipients had a HCMV load of 2.2 x 10(5)/10(6) beta-globin, 1.5 x 10(4)/10(6) beta-globin and 6.5 x 10(3)/10(6) beta-globin, respectively. In conclusion, the quantitative measurement of HCMV load in the peripheral blood correlated well with the routine HCMV antigenemia test. The DNA-based test, however can detect earlier the reactivation of the HCMV infection.

[Informative value of varying serum alpha fetoprotein levels in pregnant women based on a screening program in a Hungarian institute. What next?]. / A terhes nök eltérö szérum-alfafoetoprotein értékeinek informativitása intézetünk szüröprogramjának elemzése kapcsán. Hogyan tovább?

The authors evaluated the maternal serum alfa fetoprotein screening data of 3 years period. Out the neural tube defects they observed increased values at 20% of another congenital malformations. At the pregnant having abnormal serum alfa fetoprotein significantly accumulated the late-term abortion, stillbirth and preterm delivery. At the mothers of stillborns and abortions frequently noticed the different values. They direct attention to the fetal-living-danger importance, control functions of the abnormal level and after prospective data collection it may have new aspecific alarm role too. Accordingly the maternal serum alfa fetoprotein may consider like fetal blood sediment examination.

[Differences in the development of Hungarian children, raised at home or in a child day care center]. / Unterschiede in der Entwicklung von ungarischen Kindern, die zu Hause oder in einer Kinderkrippe erzogen wurden.

1. There are differences with regard to development of children educated at home only or at crèches additionally. 2. These differences concern as well the somatic, psychic as social development. 3. The importance of these findings are discussed.