[In vitro exposure of human nasal mucous membrane cells and lymphocytes to snuff]. / In-vitro-Exposition humaner Nasenschleimhautzellen und Lymphozyten mit Schnupftabak.

BACKGROUND: While an abundant number of studies concerning tobacco smoke and chewing tobacco show carcinogenic potential, there is little data on the consequences of snuff, especially on the cellular level. Therefore, the mutagenic effect of snuff is difficult to estimate and the WHO assessment of snuff being not carcinogenic is based on very limited data. OBJECTIVES: This paper investigates the potential cytotoxic and genotoxic effects of snuff on human lymphocytes and nasal mucosa cells. MATERIALS AND METHODS: Two types of snuff were used: one without menthol and one with a high degree of menthol. The necessary nasal mucosa cells and lymphocytes were collected from 10 subjects undergoing nasal obstruction surgery and incubated for one hour with a snuff-DMSO mixture (range 0.01-2000 µg/ml). Methods included the trypan blue test, the comet assay, and the micronucleus test. RESULTS: The trypan blue test showed no decrease in cell viability for either cell type. The comet assay revealed a significant increase in the Olive Tail Moment for lymphocytes starting at 100 µg/ml and at 1000 µg/ml for nasal mucosa cells. There was no significant increase in micronuclei according to the micronucleus test. No differences between these two types of tobacco were observed. CONCLUSION: The present study demonstrated genotoxic damage, such as DNA strand breaks, which may be repaired, but no non-repairable elevated micronuclei. The present findings cast doubts on the WHO assessment that snuff is not carcinogenic. However, for a sound assessment of the risk potential of snuff, further research on various genotoxic endpoints in human cells is warranted.

Maternal/paternal sharing of DQ-Alpha type II histocompatibility antigens not associated with pregnancy outcome following in vitro fertilization (IVF)-embryo transfer (ET).

PURPOSE: To determine if maternal/paternal sharing of DQ alpha major histocompatibility (MHC) type II antigens is associated with reduced pregnancy and implantation rates following in vitro fertilization-embryo transfer (IVF-ET). METHODS: Prospective study with type II MHC DQ alpha alleles detected by polymerase chain reaction (PCR) technology using Perkin Elmer Amyli-type HLA DQ alpha PCR amplification and typing kit. The tests were only performed on patients having their first IVF cycle. RESULTS: No difference was found in clinical pregnancy rates per transfer between those couples sharing DQ alpha I alleles and those who did not (43.7% vs 40%). There were no spontaneous abortions in the group sharing DQ alpha I alleles. CONCLUSION: Maternal/paternal sharing of DQ alpha I antigens does not reduce fecundity following IVF-ET.

Comparison of an enzyme-linked immunosorbent assay vs radioimmunoassay for measuring serum progesterone at low levels.

Reports have suggested a correlation between low serum progesterone (P) levels prior to human chorionic gonadotropin (hCG) administration and increased pregnancy rates in patients undergoing in vitro fertilization (IVF) patients. We have published two opposite conclusions, dependent upon the methodology used. Pregnancy rates were higher when P by radioimmunoassay (RIA) was < 1 ng/mL, but no increase in pregnancy rates were found when P was measured by the same company's non-isotopic assay. To test if the lack of correlation was attributable to the P method, sera from IVF patients were assayed by two methods, RIA and enzyme linked immunosorbent assay (ELISA). There was 81.8% agreement between methods. Further studies are needed to determine the importance of low P; however, if non-isotopic methods are used, the IVF center should carefully determine the accuracy of their assay in the low range.

Falsely elevated steroidal assay levels related to heterophile antibodies against various animal species.

Two cases of falsely elevated serum estradiol and 1 case of spuriously elevated serum progesterone performed on an automated immunoassay instrument are described. Further testing of same specimens indicated the presence of heterophilic antibodies against rabbit IgG and sheep IgG, respectively.