Occupational lead exposure and blood pressure.

BACKGROUND: To assess the relation between occupational lead exposure and elevated blood pressure with consideration of a possible confounding effect by noise exposure. MATERIALS AND METHOD: Some 112 male and 110 female workers at two lead battery manufacturing factories were recruited for this 1992 study in Taiwan. Study participants received regular physical examinations, including standard measurement of blood pressure, body height/weight. Current occupational exposures to lead and noise were measured by a personal sampling scheme and instruments, and included individual ambient lead/noise exposure and blood lead level. RESULTS: Among the 222 battery-factory workers, the average blood lead level was 56.9 +/- 25.5 micrograms/dl (mean +/- standard deviation), the average concentration of ambient lead exposure was 0.190 +/- 0.331 mg/m3, average noise exposure was 85.9 +/- 5.7 dBA, average systolic blood pressure was 125.2 +/- 14.9 mmHg, average diastolic pressure was 80.2 +/- 10.9 mmHg, and average mean arterial pressure was 95.2 +/- 11.1 mmHg. After considering all possible confounding variables, multivariate regression analyses demonstrated that current blood lead level was not a significant predictor for both systolic and diastolic blood pressures in either sex. In the final model, body mass index and years of working in the factory were the only two factors significantly associated with a change in blood pressure. No evidence of an effect of ambient lead exposure or noise exposure on blood pressure were found. CONCLUSIONS: The present study suggests that short-term lead exposure, either ambient lead exposure or blood lead level, was not related to blood pressure change among workers who had been exposed at work to occupational lead. These results add to the body of evidence indicating that blood lead exposure does not adversely affect blood pressure.

Ripening of ordered breath figures

We have investigated the ripening of breath figures with variable initial order. A dramatic impact of the degree of order on the coalescence behavior is observed. As opposed to the two-droplet coalescence events common to the usual disordered droplet arrays, four-droplet coalescence cascades predominate in a perfectly hexagonal breath figure. Upon introduction of disorder, a gradual transition to a regime dominated by three-droplet cascades is observed. The statistics of coalescence cascades allows for detailed conclusions on the microscopic droplet dynamics.

Asymmetric trialkylaluminium addition to aldehydes catalyzed by titanium complexes of N-sulfonylated amino alcohols with two stereogenic centers.

The asymmetric methylation, ethylation and allylation of aldehydes using trialkylaluminium reagents catalyzed by titanium(IV) complexes of N-sulfonylated amino alcohols gave excellent enantioselectivities of up to 99% ee.

Meeting the regulatory requirements for pharmaceutical production of recombinant DNA derived products.

Genetic engineering provides the opportunity for the synthesis of human proteins and derivatives thereof which are of significant value for replacement therapy. However, in addition to genetic engineering an extensive process development has to be carried out in order to establish an economic production process and to guarantee consistently high product quality from batch to batch. This includes the characterization of the production host cell vector construct, the validation of the fermentation and the protein purification process as well as the lyophilization and the reconstitution of the final product. A number of in-process and final product controls have to be established and limits for the specification have to be elaborated to provide consistent product quality. Real time stability data have to be supplied because data from accelerated conditions do not allow extrapolation of the shelf life of proteins. Data obtained from process development and validation of the production process contributes to the preparation of the chemical pharmaceutical dossier and the expert report to be submitted to the regulatory authorities.

Liquid morphologies on structured surfaces: from microchannels to microchips

Liquid microchannels on structured surfaces are built up using a wettability pattern consisting of hydrophilic stripes on a hydrophobic substrate. These channels undergo a shape instability at a certain amount of adsorbed volume, from a homogeneous state with a spatially constant cross section to a state with a single bulge. This instability is quite different from the classical Rayleigh Plateau instability and represents a bifurcation between two different morphologies of constant mean curvature. The bulge state can be used to construct channel networks that could be used as fluid microchips or microreactors.

Validation of biotechnological production processes.

Due to the biological synthesis of biotechnologically produced pharmaceuticals the product quality and safety of the drug is influenced by various factors. The correct nucleotide sequence and stability of the host cell/vector system provide the corresponding amino acid sequence of the protein. The posttranslational processing of the protein requires a well characterized production cell line. Suitable equipment for fermentation allowing a sterile production of the producing monoculture and consistent conditions are the basic requirements for the validation of the fermentation process. A constant specific productivity is one of the major criteria for the reproducibility of the production. For the validation of recovery and purification it is necessary to examine yield after each process step, product quality before and after each single process step and purification factors for removal of contaminating proteins, nucleic acids and potential viruses. In addition to the validation of the entire production process, reproducibility of quality of the formulated product has to be determined by a number of protein analytical, immunological and biochemical test methods concerning the identity, purity, safety and potency of the drug.

Oxidative dehydrogenation on the alpha-carbon of 4-pyridylacetonitrile complexes of pentaammineruthenium(II).

The oxidation of Ru(NH(3))(5)NCCH(2)py(2+) in 0.10 M HCl turns the solution from yellow to greenish blue with an absorption at lambda = 791 nm. The absorbance reaches its maximum value when the complex undergoes a two-electron oxidation. The IR and (1)H NMR spectra of the product indicate that the metal center remains as Ru(II) and that the ligand is oxidized. The (13)C NMR spectral results suggest that the oxidation product is [(NH(3))(5)RuNCC(pyH)C(pyH)CNRu(NH(3))(5)](ClO(4))(6). Cyclic voltammetry of the product solution also indicates that the oxidation proceeds in two one-electron steps corresponding to [Ru(III),Ru(II)] + e(-) <= => [Ru(II),Ru(II)] and [Ru(III),Ru(III)] + e(-) <= => [Ru(III),Ru(II)]. The structure of the product in deprotonated form [(NH(3))(5)RuNCC(py)C(py)CNRu(NH(3))(5)](ClO(4))(4)(H(2)O)(2) was determined crystallographically. [(NH(3))(5)RuNCC(py)C(py)CNRu(NH(3))(5)](ClO(4))(4)(H(2)O)(2) crystallizes in the orthorhombic Pbca space group with cell constants a = 13.7138 (16) A, b = 15.7553 (18) A, c = 17.831(2) A, and Z = 4. A mechanism for the oxidation has been proposed on the basis of the kinetic studies in the region of 0.01-0.20 M acid concentrations.