Dynamic control over catalytic function using responsive bisthiourea catalysts.

Two novel bisthiourea molecular motor-based catalysts were designed and their dynamic control of activity and stereoselectivity in the Henry reaction using heat and light as external stimuli was investigated. Enantioselective organocatalysis studies established that a basic functional group is not required within the catalyst core to effect efficient dual stereocontrol, illustrating novel stimuli responsive organocatalysts.

Comparative squalene synthase gene expression in mouse liver and testis.

RNA from various mouse organs was analyzed by Northern hybridization to determine the response of squalene synthase (SQS) mRNA to dietary cholesterol, or lovastatin and cholestyramine, administration. Two size-classes of highly abundant mouse SQS (mSQS) mRNAs of approximately 1.9 and 2.0 kb were found in testis. These transcripts were unresponsive to sterol regulation. A single size-class of liver mSQS mRNA of approximately 1.9 kb was sterol-regulated. Studies using primer extension and 5' rapid amplification of cDNA ends (RACE) indicated that the size differences in liver and testis mSQS transcripts were due to variations in the lengths of the 5' untranslated regions (UTRs). The longest testis 5' UTR extended approximately 106 nt 5' of the primary transcription initiation site in liver of mice fed lovastatin and cholestyramine. These results suggest that tissue-specific promoter elements control the transcriptional regulation of the promoters for the mSQS gene in liver and testis.

Genetic variation within and among patches of the clonal species, Vaccinium stamineum L.

Once thought to be dominated by a few genets, clonal plant populations can contain high levels of genetic diversity. Sexual reproduction and vegetative growth strategy affect the amount and distribution of genetic diversity within clonal plant populations. We determined the scale of genetic diversity in a population of Vaccinium stamineum, a clonal shrub that forms discrete patches. Using the random amplified polymorphic DNA (RAPD) technique, we surveyed the genetic diversity of V. stamineum within and among patches from a 1-ha site. We found 67 unique RAPD profiles among the 99 sampled individuals from 22 patches. In two patches, all the sampled individuals had the same RAPD profile. In seven patches, every individual sampled had a different RAPD profile. The remaining patches showed mixed RAPD profiles which suggested both clonal and sexual reproduction. Each unique RAPD profile was restricted to one patch (with one exception), which suggests that clonal growth occurs at the patch scale. High levels of genetic variation within some patches may be explained by somatic mutation; however, seedling recruitment is a more likely explanation.

Women, work and health: issues and implications for worksite health promotion.

This paper identifies issues related to worksite health promotion programs for women by examining ways that work factors, health behaviors, family roles and responsibilities, and women's health are linked. Work conditions may affect women uniquely, as in the case of chemical exposure affecting reproductive health; disproportionately, such as the interaction between work and family roles; or differently from men, as in women's experience of stress in the workplace. The focus is on the differences and uniqueness of working women's health. Drawing on a public health perspective, implications for consideration by worksite health promotion programs specialist, human resource managers, and researchers are presented.

T antigens encoded by replication-defective simian virus 40 mutants dl1135 and 5080.

We present a preliminary biochemical characterization of two simian virus 40 mutants that affect different T antigen replication functions. SV40 T antigen mutants dl1135 (delta 17-27 amino acids) and 5080 (P-L) have been studied extensively with regard to their ability to transform cells in culture and induce tumors in transgenic mice. Both mutants are defective for viral DNA replication in vivo. In order to assess in more detail the molecular basis for the in vivo replication defects of 5080 and dl1135, we expressed the mutant proteins using the baculovirus system and purified them by immunoaffinity chromatography. With each of the purified proteins, we examined some of the biochemical activities of T antigen required for replication, viz. ATPase, binding to the origin of replication (ori) and assembly on ori, DNA helicase and unwinding, and replication in in vitro assays. Consistent with previous studies, we found that the 5080 protein is defective for multiple biochemical activities including ATPase, helicase, ori-specific unwinding, and ATP-induced hexamerization. However, this mutant retains some sequence-specific DNA binding activity. In contrast, the dl1135 protein exhibited significant levels of activity in all assays, including the ability to drive SV40 DNA replication in vitro. Thus, dl1135 is one of several mutants with an altered amino-terminal domain which can replicate DNA in vitro, but not in vivo. Thus, while the 5080 mutation affects a T antigen enzymatic function directly required for viral DNA synthesis, dl1135 may alter an activity required to prepare the cell for viral replication.

Health promotion in a shrinking military: the call for structural integration and a conceptual systems approach.

The evolution of health promotion in the military is reviewed and contrasted with developments in private sector activities. Programs in both arenas generally take a mechanistic, mortality and risk factor-based approach which targets lifestyle and behavioral change. In the military, that has resulted in a fragmentation of function and perception in the line and medical communities about health promotion. A "world view" model and a conceptual systems approach to health promotion are presented in which human resources, occupational health, life-style, and health benefits programs are integrated to achieve efficiencies in program management, decreased mortality, and reduced medical care costs.

Effect of early antibiotic treatment on the formation of sperm antibodies in experimentally induced epididymitis.

This investigation was conducted to evaluate whether or not experimentally produced epididymitis could induce the development of cytotoxic sperm antibodies and if effective antibiotic therapy could reverse the development of immunity to sperm. Escherichia coli was injected into the tail of the epididymis in adult Lewis rats to induce epididymitis and was allowed to incubate for 24 h, 72 h, 8 days, or 15 days. Serum titers of cytotoxic sperm antibodies at these time intervals were determined. Sperm antibody titers began to rise 3 days after inoculation, peaked, and plateaued at 8 days. The titers were negligible in the control rats. Two other groups of rats were inoculated with E. coli in a similar manner and were treated with tetracycline 25 mg/kg/day starting at either 24 h or 8 days after inoculation, for 7 days. The antibody titers became negligible in these two treated groups, the results being statistically significant when contrasted with the infected but untreated groups (p < .001 and < .05, respectively, for the 24-h and 8-day groups). However, histological examination of the antibiotic-treated and untreated specimens revealed significant inflammation and infection of the epididymis in both treated groups. Testicular alterations were consistent in both groups. It is concluded that epididymitis consequent to infection with E. coli can induce cytotoxic antibody formation in Lewis rats. Treatment with appropriate antibiotics may suppress the antibody response either through a direct immunosuppressive effect of the antibiotic or through a decrease in the antigenic load of killed sperm secondary to eradication of the infection.

The high maltose-producing alpha-amylase of the thermophilic actinomycete, Thermomonospora curvata.

The alpha-amylase of Thermomonospora curvata catalyses the formation of very high levels of maltose from starch (73%, w/w) without the attendant production of glucose. The enzyme was produced extracellularly in high yield during batch fermentation in a 5-1 fermentor. Purification was achieved by ammonium sulphate fractionation, Superose-12 gel filtration and DEAE-Sephacel ion-exchange chromatography. The enzyme exhibited maxima for activity at pH 6.0 and 65 degrees C, had a relative molecular mass of 60,900-62,000 and an isoelectric point at 6.2. The exceptionally high levels of maltose produced and the unique action pattern exhibited on starch and related substrates indicate a very unusual maltogenic system. The predominance of maltose as the final end-product may be explained by the participation of reactions other than simple hydrolysis and the preferential cleavage of maltotriose from higher maltooligosaccharides. The enzyme exhibits very low affinity for maltotriose (Km = 7.7 x 10(-3) M) and its conversion to maltose is achieved by synthetic followed by hydrolytic events, which result in the very high levels of maltose observed and preclude glucose formation. This system is distinguished from other very high maltose-producing amylases by virtue of its high temperature maximum, very low affinity for maltotriose and the absence of glucose in the final saccharide mixture.

Pathological and immunological effects of surgically induced varicocele in juvenile and adult rats.

The presence of a varicocele in adult men has been correlated with infertility. This study documents the effect of an experimentally induced unilateral varicocele in 21-day-old juvenile prepubertal and 51-day-old adult rats (n = 10 per group) on subsequent adult testicular function. Varicoceles were induced by partial occlusion of the spermatic vein. There were ten sham-operated and five nonoperated control rats in each age group. The rats were sacrificed 1 month after surgery. Intrascrotal temperatures were elevated in both groups with varicoceles. Histologically, the ipsilateral testes of rats in both age groups demonstrated a decrease in the numbers of functioning seminiferous tubules and germ cells, but the decrease was significantly greater in the juveniles than in the adult rats. No changes were seen in the contralateral testes. Significant titers of cytotoxic sperm antibodies were present in all animals with varicoceles, which is in contrast to controls. The juveniles had significantly lower antibody titers (mean log2 +/- SEM; 3.2 +/- 0.09 vs. 8.5 +/- 1.1, P less than 0.001) than the adults. The induction of a unilateral varicocele damaged spermatogenesis and testicular function to a greater extent in juveniles than in adult rats. This damage may be immune complex-mediated.

Pulmonary hemorrhage and air embolism complicating transbronchial biopsy in pulmonary amyloidosis.

We describe a fatal complication of transbronchial biopsy in a patient with pulmonary parenchymal amyloidosis. Hemorrhage after biopsy required intubation and positive-pressure ventilation that resulted in massive arterial air embolism. Postmortem findings suggested that the bleeding and air embolism were related to persistent patency of biopsied blood vessels infiltrated with amyloid. Patients with pulmonary amyloidosis may be at increased risk of major complications after transbronchial biopsy.

Separation of the messenger RNAs of Newcastle disease virus by gel electrophoresis.

We have separated the 18-22S putative messenger RNA of Newcastle disease virus into seven species ranging in molecular weight from 0.55 to 1.53 x 10(6) using sodium dodecyl sulfate-acrylamide-gel electrophoresis at relatively high concentrations of acrylamide and for a relatively long time. Studies of the number and molecular weights of the proteins and the 18-22S RNAs of the virus suggests that these RNAs are in the right molecular weight range to code for the known proteins of Newcastle disease virus. In preliminary studies using this separation technique, we have demonstrated that: (a) there is no difference between the 18-22S RNA made during a normal infection and when genome replication is blocked; and (b) there is a strain-specific difference between the RNAs of Newcastle disease virus-AV and Newcastle disease virus-HP.

A 0.2-MW Furnace for Spectroscopic Studies.

A large King furnace is described for use in the measurement of relative oscillator strengths by the absorption method. Design criteria are discussed, and representative traces of absorption lines obtained with the Oxford low noise spectrometer are shown. The rms noise level given by the apparatus at a wavelength of 4427 A and with a resolving power of lambda/ Deltalambda = 1.1 x 10(5), is 0.03% of the continuum, using an integration time of 16 sec per point.