Economic hardship and sexually transmitted diseases in Haiti's rural Artibonite Valley.

A study was conducted to determine the prevalence rate and risk factors for sexually transmitted diseases (STDs) in Haiti's rural Artibonite Valley. Women attending antenatal services at Hospital Albert Schweitzer from October to December 1996 were tested for gonorrhea, chlamydia, trichomonas, syphilis, and human immunodeficiency virus (HIV). Of the 476 women tested, 121 (25.4%) had trichomonas, 11/475 (2.3%) had gonorrhea, 51/475 (10.7%) had chlamydia, 32/474 (6.8%) were seropositive for syphilis, 20/469 (4.3%) were seropositive for HIV, and 191 (40.1%) had at least one STD. Nearly 30% of the women reported having entered a sexual relationship out of economic necessity and had increased odds of HIV infection, Odds Ratio (OR) 6.3 (P < 0.001). We postulate that due to recent economic hardship in rural Haiti, women are entering into sexual relationships out of economic necessity and that this trend is contributing to the growing HIV epidemic. We recommend STD prevention and development programs that target young people and economically disadvantaged women.

Intra-aortic balloon pump counterpulsation in the management of concomitant cerebral vasospasm and cardiac failure after subarachnoid hemorrhage: technical case report.

We report two patients who had symptomatic cerebral vasospasm and cardiac failure after aneurysmal subarachnoid hemorrhage and who were treated successfully with intra-aortic balloon pump counterpulsation therapy. Both patients developed congestive heart failure and pulmonary edema while receiving postoperative hypertensive, hypervolemic, hemodilutional (Triple-H) therapy for symptomatic cerebral vasospasm. Both cases of cardiac failure were refractory to maximum pressor and inotropic infusions. Intra-aortic balloon pump counterpulsation was used to optimize cardiac performance to allow continuation of Triple-H therapy and to maintain adequate cerebral perfusion in an attempt to decrease the risk of cerebral ischemic complications. Both patients have had good long-term outcomes. These two cases illustrate the potential usefulness of the intra-aortic balloon pump as an adjunct to Triple-H therapy in patients with symptomatic cerebral vasospasm and cardiac failure. To our knowledge, this report documents the first clinical application of this adjunctive therapy for vasospasm after aneurysmal subarachnoid hemorrhage.

Model of the aerosol extinction profile in a well-mixed marine boundary layer.

A simple model is described which predicts the vertical profile of aerosol extinction and the aerosol optical thickness at visible wavelengths in a well-mixed marine boundary layer, given the relative humidity and aerosol extinction coefficient at the surface (shipboard level) and the height of the boundary layer. The model is presented in the form of both analytical approximation formulas and nomograms.

Atresia of the left main coronary artery: repair with left internal mammary artery bypass.

The case of a 17-month-old child with atresia of the left main coronary artery and mitral insufficiency is presented. The child underwent two separate surgical procedures, the first being a left internal mammary-left anterior descending coronary artery bypass and plication of the mitral valve. During the follow-up period the mitral insufficiency progressed, and the child subsequently underwent mitral valve replacement with a Björk-Shiley prosthesis. A selective study of the left internal mammary demonstrated excellent flow into the left coronary artery system. The report illustrates the use of the left internal mammary artery in a small child.

Microbial transformation of sulfate in forest soils.

Incubation of forest soils containing sulfate labeled with sulfur-35 showed rapid conversion of the added sulfate to organic sulfur forms by microbial populations. Activity rates were highest in the forest floor, but significant activity was observed throughout the soil profile. The annual potential sulfur incorporation for forest floor and soil combined is estimated to be 30 kilograms per hectare. The metabolism of inorganic sulfate to organic forms can be a major process in the sulfur cycle, influencing sulfate accumulation and mobility in forest ecosystems.

The primary alkylsulfatase of Pseudomonas aeruginosa: inducer specificity and induction kinetics.

The ability of primary alkylsulfate esters and alkanesulfonates to induce alkylsulfatase formation in Pseudomonas aeruginosa was compared on the basis of maximum enzyme levels, induction rate, and levels of induction as a function of inducer concentration. Apparent K inducer values for these effectors were calculated from linear relationships between reciprocals of induction rate and inducer concentration. Maximum enzyme levels estimated from linear progress relationships for each effector indicated that little major distinction could be made between effectors. Excepting carbon chain lengths of C8 which induced about the same level of enzyme, sulfate esters were generally better inducers than sulfonates with little or no apparent induction occurring with effectors of chain length less than or equal to C6. These observations also held true when rates were compared, except that the rate for the C8 ester was approximately ninefold greater than that for the analogous sulfonate. Apparent K inducer constants decreased with increasing alkyl chain length for the esters (C6-C12) and the sulfonates (C8-C14). Values for the esters were approximately sixfold greater than those for sulfonates of equivalent chain length. Plots of log apparent K inducer values against carbon chain length for each series of esters and sulfonates yielded straight-line relationships characteristic of an homologous series in each instance.

Stimulation of bacterial arylsulfatase activity by arylamines: evidence for substrate activation.

A number of arylamines (including tyramine and tryptamine) increased the in vitro activity of arylsulfatase from Pseudomonas sp. strain C12B. Amino acid analogs of these amines (e.g., tyrosine and tryptophan) failed to exert an effect. Stimulation of activity by tyramine could not be accounted for in terms of sulfotransferase activity for this phenol, and no shift in the pH optimum for the enzyme occurred in the presence of tryptamine. Increased Vmax due to these amines was independent of enzyme concentration but varied significantly with substrate concentration. Evidence is presented which suggests that arylamines enhance arylsulfatase activity by forming a salt linkage with the substrate and rendering it more susceptible to enzymatic and acid-catalyzed hydrolyses. The recrystallized tryptamine salt of the substrate exhibited a reduced affinity for the enzyme but was hydrolyzed more rapidly than the potassium salt, which is normally employed as the assay substrate.

Arylsulfatase from Pseudomonas sp. strain C12B: purification to homogeneity, immunological analysis, and physical properties.

Arylsulfatase was purified 219-fold from Pseudomonas sp. strain C12B. The final preparation was homogeneous by electrophoretic and immunological analysis. The enzyme is a monomer of molecular weight about 51,000, with a Stokes radius of 3.0 X 10(-7) cm, a frictional ratio of 1.2, and a sedimentation coefficient of 4.1S.

Regulation of primary alkylsulfatase induction in Pseudomonas C12B: concentration-dependent stimulation-inhibition by exogenous UTP and sodium acetate and inhibition by 1-hexanol.

Pseudomonas C12B, an isolate from detergent-enriched soil, synthesized primary alkylsulfatase in response to sodium hexan-1-yl sulfate as the inducer. The induction of this enzyme was inhibited by exogenous 1 mM UTP but not by ATP or other nucleoside triphosphates. The uridine nucleotide was about 10-fold more effective than other uracil-related effectors and the ability of the nucleotide (0.1-1.0 mM) to inhibit induction was dependent upon the presence of added Mg2+. At concentrations less than 0.1 mM, UTP stimulated induction and the extent of this effect was also Mg2+ dependent. Marked stimulation of induction also occurred in response to low (less than or equal to 2.5 mM) concentrations of acetate, citrate, and succinate. However, only acetate inhibited induction (by 64%) at higher (20 mM) concentrations. 1-Hexanol was a more effective inhibitor. An 80% reduction in activity was recorded after exposure of cells to 5 mM 1-hexanol. At this concentration, 2-hexanol was without effect and 3-hexanol inhibited induction by 35%. Simultaneous exposure of the cells to 2,4-dinitrophenol failed to reverse hexanol- or acetate-mediated inhibition. It is suggested that 1-hexanol per se regulates alkylsylfatase induction and immediate product inhibition was proposed as a term to describe this type of inhibition.

Specificity of P2 primary alkylsulphohydrolase induction in the detergent-degrading bacterium Pseudomonas C12B. Effects of alkanesulphonates, alkyl sulphates and other related compounds.

Primary alkanesulphonates were shown to serve as non-metabolizable (gratuitous) inducers of the P2 primary alkylsulphohydrolase enzyme in resting cell suspensions of Pseudomonas C12B. The effects of increasing concentrations of inducer on the production of enzyme were complex and suggestive of a multiphasic phenomenon. However, it was possible to determine Kinducer constants (analogous to Km or Ki) for alkanesulphonates of chain length from C7 to c12. these decreased with increasing chain length in a manner characteristic of an homologous series. Primary alkyl sulphates also served as good inducers of alkylsulphohydrolase, but valid kinetic values could not be obtained because these esters are good substrates for the enzyme and are therefore appreciably hydrolysed during the induction period. Small amounts of enzyme were also produced when cyprinol sulphate, dodecyltriethoxy sulphate C12H23-[O-CH2-CH2]3-O-SO3-Na+), Crag herbicide and some secondary alkyl sulphates were tested as inducers.

Purification and properties of the P2 primary alkylsulphohydrolase of the detergent-degrading bacterium pseudomonas C12B.

The P2 primary alkylsulphohydrolase of the soil bacterium Pseudomonas C12B was purified to homogeneity (200-250-fold) by column chromatography on DEAE-cellulose, Sephadex G-100 and butyl-agarose. The intact protein is a dimer with a mol. wt. of 160 000. Activity towards primary alkyl sulphate esters was maximal at pH 8.3, varied little in the range pH 7.8-8.7, but decreased sharply at higher pH. For a homologous series of primary alkyl sulphate substrates (C6-C12), logKm decreased linearly with increasing chain length, corresponding to a contribution to the free energy of association between enzyme and substrate of -2.5kJ/mol for each additional CH2 group in the alkyl chain. logKi for the competitive inhibition by secondary alkyl 2-sulphate esters followed a similar pattern (-2.4kJ/mol for each additional CH2 group) except that only n-1 carbon atoms effectively participate in hydrophobic bonding, implying that the C-1 methyl group is not involved. logKi values for inhibition primary alkanesulphonates also depended linearly on chain length but with a diminished gradient, indicating a free-energy increment of -1.2kJ/mol per additional CH2 group. The collective results showed the presence of a hydrophobic site on the enzyme capable of accomodating an alkyl chain of considerable length. Cationic structures (in the form of arginine, lysine or histidine), whose presence might be expected for binding the anionic sulphate group, were not detectable at the active site.

Effect of divalent cations on the inhibition of alkylsulfatase induction and the generation of ATP in Pseudomonas aeruginosa after exposure to exogenous uridine 5'-triphosphate.

In the absence of added Mg2+, alkylsulfatase induction in resting cells of Pseudomonas aeruginosa was inhibited 17% by exogenous 0.05 mM UTP. Under these conditions, the cells converted UTP to ATP and rapid degradation of these nucleotides did not occur. In the presence of 0.73 mM Mg2+, 0.05 mM UTP repressed the synthesis of the enzyme by 71%. Under these conditions, the cells rapidly degraded both ATP derived from UTP as well as residual UTP. In the presence of Mg2+ and 0.1 mM UTP, full repression of alkylsulfatase formation occurred whereas Mg2+-depleted cell suspensions were still capable of synthesizing 47% of the enzyme under these conditions compared with control levels. The inhibition of alkylsulfatase induction was highly specific for UTP. Some inhibition was observed with exogenous uracil, uridine, and pyrophosophate but only at concentrations greater than 1.0 mM. Exogenous UMP and UDP (2mM) had no effect.

Evidence for a periplasmic location in Comamonas terrigena of the inducible tyrosine sulfate sulfohydrolase.

The location of the inducible and constitutive forms of tyrosine sulfate sulfohydrolase in Comamonas terrigena was investigated by subjecting resting cells to osmotic shock and to treatment with lysozyme in the presence of EDTA. The bulk of this enzyme present in induced cells was released by these procedures, suggesting that the induced form is cell wall associated. The constitutive form present in noninduced cells was not released under these conditions. Evidence was also presented which suggests that SO4(2-)release by intact cells during exposure to tyrosine sulfate was primarily due to the action of the inducible form of the enzyme.