Microcell-mediated cotransfer of genes specifying methotrexate resistance, emetine sensitivity, and chromate sensitivity with Chinese hamster chromosome 2.

Many selectable mutants of somatic Chinese hamster cells have been described, but very few of the mutations have been mapped to specific chromosomes. We have utilized the microcell-mediated gene transfer technique to establish the location of three selectable genetic markers on chromosome 2 of Chinese hamster. Microcells were prepared from the methotrexate-resistant MtxRIII line of Flintoff et al. (Somatic Cell Genet. 2:245-261, 1976) and fused to wild-type CHO cells, and microcell hybrids (transferants) were selected in medium containing methotrexate. All transferants were karyotyped and found to contain a marker chromosome from the donor MtxRIII line. This marker chromosome, called 2p-, consisted of a chromosome 2 with a reduced short arm resulting from a reciprocal translocation between 2p and 5q. In experiments utilizing emetine-resistant (Emtr) or chromate-resistant (Chrr) recipient cells it was found that the emt+ and chr+ wild-type genes were cotransferred with the 2p- chromosomes. Karyotype analysis of several transferants with rearranged or broken 2p- markers allowed regional localization of the emt and chr loci to the proximal third of the long arm and localization of the gene or genes conferring methotrexate resistance to the short arm. These results confirm our earlier assignment of the emt and chr loci to chromosome 2 in Chinese hamster.     

Chiral stationary phases in concert with homologous chiral mobile phase additives: Push/pull model

A new “push/pull” model has been developed to explain synergistic effects observed in a system in which a chiral stationary phase (CSP) is used in combination with its homologous chiral mobile phase additive (CMPA). The model predicts the beneficial CMPA enantiomer and the counterproductive CMPA enantiomer a priori. Thus, an (R)-CSP will obtain positive synergism from a homologous (S)-CMPA and negative synergism from a homologous (R)-CMPA. The reverse is true for an (S)-CSP. The importance of structural homology between the CSP and the CMPA is demonstrated. Furthermore, the analysis time is decreased relative to the use of a CSP alone, because the retention time of the analyte peaks decreases when the CMPAs are used. © 1993 Wiley-Liss, Inc.     

Treatment of fish processing waste using the downflow stationary fixed film (DSFF) reactor

Summary The DSFF reactor has been shown to be capable of treating a wide variety of wastes. In this study, a high protein fish processing waste was treated at several influent concentrations. Chemical oxygen demand (COD) removal efficiencies of up to 90% were achieved at loading rates in excess of 10 kg COD/m³/day.     

Interleukin-1 receptor antagonist allele (ILIRN*2) associated with nephropathy in diabetes mellitus

We have previously found association between an allele of the interleukin-1 (IL-1) receptor antagonist gene (ILIRN) and several inflammatory diseases, where IL-1 has been implicated in the inflammatory mechanism. We have now, therefore, tested the association of this specific allele (ILIRN*2) with complications of diabetes which have an inflammatory tissue component. We have tested the allele frequency of ILIRN*2 in 128 patients with insulin-dependent and 125 with non-insulin-dependent diabetes mellitus (NIDDM). There was a significant association between carriage of ILIRN*2 and diabetic nephropathy (P < 0.0001,P _corrected < 0.0012). The association was significant in both types of diabetes, but the observed increase was highest in NIDDM, rising to double the control levels. It appears that ILIRN*2 is a novel genetic marker of severity of inflammatory complications of diseases rather than a marker of disease susceptibility. If the DNA polymorphism is associated with altered gene function, new therapeutic interventions may be possible.