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In Staphylococcus aureus, the transcription factor CodY modulates the expression of hundreds of genes, including most virulence factors, in response to the availability of key nutrients like GTP and branched-chain amino acids. Despite numerous studies examining how CodY controls gene expression directly or indirectly, virtually nothing is known about the extent to which CodY exerts its effect through small regulatory RNAs (sRNAs). Herein, we report the first set of sRNAs under the control of CodY. We reveal that staphylococcal sRNA RsaD is overexpressed >20-fold in a CodY-deficient strain in three S. aureus clinical isolates and in S. epidermidis. We validated the CodY-dependent regulation of rsaD and demonstrated that CodY directly represses rsaD expression by binding the promoter. Using a combination of molecular techniques, we show that RsaD posttranscriptionally regulates alsS (acetolactate synthase) mRNA and enzyme levels. We further show that RsaD redirects carbon overflow metabolism, contributing to stationary phase cell death during exposure to weak acid stress. Taken together, our data delineate a role for CodY in controlling sRNA expression in a major human pathogen and indicate that RsaD may integrate nutrient depletion and other signals to mount a response to physiological stress experienced by S. aureus in diverse environments., (© 2019 John Wiley & Sons Ltd.)

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.

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.

Resting ECGs, exercise treadmill tests and 24-hour ambulatory ECGs were recorded and analyzed in 24 unselected patients with mitral valve prolapse. Arrhythmias were frequent. There were three distinct groups of patients, defined on the basis of total number of premature ventricular contractions (PVCs) during the 24 hours; there were no PVCs in 25%, and frequent PVCs in 50%. Complex ventricular arrhythmias, including ventricular tachycardia in five patients, were found almost exclusively in the group with frequent PVCs. Fifteen of the 24 patients demonstrated atrial premature contractions (APCs) during the 24 hours. Complex atrial arrhythmias were found among patients with infrequent, as well as those with frequent, APCs. Supraventricular tachycardia was detected in seven of these patients. The incidence of ACPs decreased during sleep in 67% of the patients and showed no change during sleep in 33%. A poor correlation was found between symptoms recorded in patient diaries and changes noted on 24-hour ECG recordings. The peak PVCs/15 min and peak ACPs/15 min during a 24-hour period of monitoring was found to be an excellent guide to the total number of PVCs and APCs occurring during that period. This permits an accurate prediction of the total number of PVCs in 24 hours after performing an exact PVC count on only 15 minutes of ECG data. Finally, the 24-hour ambulatory ECG was sensitive than the treadmill test and both were superior to the 12-lead ECG for detecting arrhythmias in these patients.

Alkylsufatase induction in resting cell suspensions of P. aeruginosa was inhibited by exogenously supplied adenosine or by ATP (2mM). Adenine phosphate had no effect while AMP or ADP caused a slight stimulation of induction. The inhibitory effect of ATP required the presence of added Mg2+, was not reversed by cyclic-AMP (2mM), and was independent of the nature of the inducer. Of a number of other nucleoside triphosphates tested, only UTP (2mM) acted as an inhibitor of induction. These nucleotides at external concentrations of 6mM also inhibited alkysulfatase induction in actively growing cells.

When Pseudomonas C12B is grown on nutrient broth to the stationary phase, cell extracts contain two secondary alkylsulphatases (S1 and S2) active towards potassium decan-5-yl sulphate but not towards potassium pentan-3-yl sulphate and one primary alkylsulphatase (P1) active towards sodium dodecan-1-yl sulphate (sodium dodecyl sulphate). When 10mm-sodium hexan-1-yl sulphate is included in the nutrient broth an additional primary alkylsulphatase (P2) is produced. The S1, S2, P1 and P2 enzymes are also present in extracts of cells grown on broth containing the commercial detergent Oronite, together with an additional secondary alkylsulphatase (S3) active towards pentan-3-yl sulphate as well as decan-5-yl sulphate. The P2 primary alkylsulphatase can be induced by a number of primary and secondary alkyl sulphate esters but the induction of the S3 enzyme appears to be a more specific and complex process. Studies on the ability of different fractions separated from Oronite to act as inducers suggest that the combination of a long-chain secondary alkyl sulphate(s) and a long-chain secondary alcohol(s) is responsible for the appearance of the S3 enzyme. Potassium hexadecan-2-yl sulphate or potassium tetradecan-2-yl sulphate, in combination with either hexadecan-2-ol or tetradecan-2-ol, can serve as inducers for the enzyme. Some characteristics of these specific inducer systems have been elucidated.

Cell extracts of Pseudomonas C12B synthesized choline sulfate (COS) from SO42-, choline chloride, and ATP. However, most of the COS-forming activity was found in culture medium supernatants of this bacterium, and that which remained with the cells was cell wall-associated. Enzyme release was independent of the carbon and (or) sulfur source used for growth and was not suppressed by increasing the divalent cation concentration of the medium. The COS-synthesizing system was inhbited in vitro by L-cysteine (greater than or equal to 10(-3) mM), SO42- (greater than 0.1 mM), and choline chloride (greater than 0.1 M). L-Cysteine (0.1-5.0 mM) did not repress the synthesis of enzymes present in the system. COS formation from SO42- in vitro was increased 2.8-fold by 10 mM adenosine 5'-phosphosulfate (APS) and 5-fold by 1 mM 3'-phosphoadenosine,5'-phosphosulfate (PAPS) during a 4-h incubation period. APS (10 mM) also inhibited the incorporation of 35SO42- into COS. Culture supernatants incubated with Na235SO4 produced two 35S-labelled metabolites having electrophoretic mobilities similar to those exhibited by authentic APS and PAPS. The synthesis of these metabolites was also inhibited in vitro by unlabelled APS and by L-cysteine.

Review of 203 24-h ambulatory electrocardiographic tapes of 140 patients disclosed 32 patients with 66 episodes of paroxysmal atrial tachycardia. In contrast to classic sustained paroxysmal supraventricular tachycardia, these episodes were relatively slow and brief. The median duration was 7 beats and the mean 116 beats/min. All episodes were asymptomatic except for three prolonged paroxysms that produced mild palpitation. Sixty-eight percent (45/66) of these episodes occurred during sleep or sinus bradycardia. This was the most common paroxysmal supraventricular arrhythmia observed, and it occurred in patients with a wide variety of cardiac diagnoses. The majority of these episodes appear to arise from an atrial ectopic origin. We conclude that these brief slow atrial paroxysms represent a benign arrhythmia. This rhythm disturbance is present in as many as one quarter of cardiac patients undergoing ambulatory electrocardiographic monitoring. It should not be confused clinically with classic sustained paroxysmal supraventricular tachycardia.

Secondary alkylsulfatases (S-1 and S-2) were detected in Pseudomonas C12B cultured in minimal media lacking alkylsulfatases. The synthesis of these enzymes was not repressed by SO4-2- and L-cysteine or derepressed by L-methionine. Growth on 4% sodium citrate caused a 98% loss in the secondary alkylsulfatase activity of cells and 9% of this activity was detected in the culture medium. Citrate (20 mM) inhibited the activity of cell extracts (18%) but the inhibition was reversible by dialysis. The primary alkylsulfatase content of cells was not diminished by growth on citrate. The MgCl2 concentration of the medium also influenced the cellular levels of secondary alkylsulfatase. Bacteria grown on MgCl2 (0.05 mM - 40 mM) exhibited progressively increasing activity while the converse distribution was observed for activity present in the medium after growth at each MgCl2 concentration. Both primary and secondary alkylsulfatases were released when cells were either subjected to osmotic shock or treated for cell wall removal. Cells washed with 0.085 M sodium citrate-10 mM Tris-20%sucrose released roughly 87% of both enzymes and MgCl2 (0.04 M) inhibited the release of primary alkylsulfatase by 11% and secondary alkylsulfatase by 50%. It is suggested that citrate chelates divalent cations necessary for the attachment of secondary alkylsulfatase at the cell periphery.

The occurrence in a strain of Comamonas terrigena of secondary alkylsulphatase activity towards potassium decan-5-yl sulphate is reported. A number of cell-washing and osmotic-shock procedures for releasing bacterial exocytoplasmic enzymes were ineffective in releasing this activity. Primary alkylsulphatases are not present in the organism, nor can their formation be induced under a wide variety of experimental conditions tested.

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.

This study evaluates propranolol's effect on symptoms, arrhythmias, and exercise tolerance in 16 patients with mitral valve prolapse. Three patients (19 per cent) experienced symptomatic deterioration with propranolol therapy, seven (44 per cent) were unchanged, and six (37 per cent) noted an over-all symptomatic improvement, primarily due to a reduction in palpitation. Symptomatic improvement continues in these six patients an average of 12.5 months after beginning propranolol therapy. Treatment with propranolol alleviated chest pain in only two of eight patients and it did not improve the ability to perform treadmill exercise. Fatigue did not improve, and in three patients appeared for the first time during propranolol therapy. Premature ventricular contractions were reduced by at least 75 per cent in five of nin patients (56 per cent), and paroxysmal ventricular tachycardia was eliminated in three of four patients. We conclude that propranolol is not uniformly effective in patients with mitral vale prolapse. A trial of propranolol may be instituted fro patients with mitral valve prolapse who have severe symptoms and/or arrhythmias, but the drug should only be continued in those who demonstrate clinical and/or antiarrhythmic response.

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.

Tocainide, a new oral antiarrhythmic agent, was studied in man in a short-term protocol designed to evaluate the efficacy, kinetics, and toxicity of this compound. Premature ventricular contractions (PVCs) were suppressed by less than 70% in 11 of 15 patients compared with pre-drug placebo controls. For these 11 responders, there was an average PVC reduction of 91% +/- 10 (range 70 to 100%) at tocainide doses not associated with side effects. Mild transient central nervous system toxicity was observed in some patients near the time of peak concentrations during the highest dose administered. The drug was found to have linear kinetics over the dose range studied and a plasma half-life of 13.5 +/- 2 hours. Plasma concentration-response curves indicate antiarrhythmic activity over all plasma concentrations, with 70% PVC reduction above 6.0 mug/ml. This study suggests that tocainide is a safe and effective antiarrhythmic agent during short-term administration and is worthy of further clinical trials.

Sodium hexan-1-yl sulphate and certain related alkyl sulphate esters have been shown to serve as inducers of the formation of primary alkylsulphatases (designated as P1 and P2) in Pseudomonas C12B. When the organism is grown on sodium hexan-1-yl [(35)S]sulphate as the sole source of sulphur or as the sole source of carbon and sulphur only the P2 alkylsulphatase is formed and inorganic (35)SO(4) (2-) is liberated into the media. Cell extracts contain this anion as the major (35)S-labelled metabolite although two unidentified labelled metabolites as well as choline O-[(35)S]sulphate occur in trace quantities in some extracts. Dialysed cell extracts are capable of liberating inorganic (35)SO(4) (2-) from sodium hexan-1-yl [(35)S]sulphate without the need to include cofactors known to be required for the bacterial degradation of n-alkanes. The collective results suggest that sodium hexan-1-yl sulphate can act as an inducer of P1 alkylsulphatase formation without the need for prior metabolic modification of the carbon moiety of the ester.

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.

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.

The antiarrhythmic action of the beta-blocking drug, acebutolol, was evaluated in patients with frequent premature ventricular contractions (PVCs). In the 12 hours following administration of a single 300 mg oral dose, 8 of 10 patients showed a greater than 50% reduction in PVC frequency, and statistical analysis indicated that PVC reduction persisted for 10 hours after the single dose. Analysis of plasma concentrations of acebutolol and an acetyl metabolite indicated that after single oral doses of plasma concentrations of the metabolite exceed those of unchanged acebutolol. When patients were studied during periods of 300 mg doses every 8 hours, eight of 11 showed a 70% reduction in PVC frequency, and analysis showed that the therapeutic effect was present throughout the 24-hour monitoring period. Acebutolol slowed the heart rate and prolonged the PR interval without affecting the QT interval. Significant clinical or laboratory toxicity was not encountered. In the small group studied, acebutolol was found to be safe and effective for short-term administration to patients with frequent PVCs and possessed a relatively long duration of antiarrhythmic action.

Potassium D-glucose 6-O-[35S]sulfate was partially converted by Tris (greater than or equal 25 mM, pH 7.5) to 35SO4(2-), fructose, and a 35S-labelled compound which was tentatively identified as fructose 6-O-sulfate. The isomerization reaction was also catalyzed by ethanolamine and 2-dimethylaminoethanol but not by glycine, triethanolamine, or pentaerythritol. The significance of these findings in relation to kinetic studies of the enzyme glycosulfatase is discussed.

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.

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.

Pseudomonas aeruginosa (isolated from soil) synthesizes an alkylsufatase allowing this bacterium to utilize sodium hexan-1-yl sulfate as a source of carbon and sulfur for growth. The formation of the enzyme was induced by this and by other (C4-C16) primary alkylsulfate esters as well as by some (C-8 and C-9) primary alkylsulfonates. Secondary (2-yl) alkylsulfate esters did not act as inducers. The induction of alkylsulfatase was markedly inhibited by L-cysteine, L-methionine, sodium sulfide, and by high (greater than 2mM) concentrations of D-glucose and other related monosaccharides. Similar inhibitory effects by four glucose analogs which will not support growth suggest that prior metabolism was not a requirement for glucose-mediated inhibition. The inhibition by D-glucose of the same inducible system in P. aeruginosa (PAO-57) supported this conclusion since this glucose transport-positive mutant is deficient in the further metabolism of the monosaccharide. At low (0.1-1.0 mM) concentrations, D-glucose or D-glucose 6-O-phosphate (20 mM) caused a marked enhancement of alkylsulfatase induction in the isolate. This novel enhancement was reproduced using P. aeruginosa strain PAO. However, both monosaccharides acted as potent inhibitors of alkylsulfatase formation occurring in mutant PAO-57 which, unlike the parent strain PAO, exhibits low glucose-6-phosphate dehydrogenase activity. These results suggest that D-glucose (0.1-1.0 mM) must be metabolized to enhance the synthesis of the enzyme.

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.

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.

The development of the ability to record a patient's ECG during a full 24-hour day of normal activities has resulted in improved arrhythmia detection and potential for treatment. Improved methods of ECG data processing, using computer techniques, now allows quantitation of PVC frequency and improved correlation of the arrhythmia with events occurring during the period of recording. Knowledge of the natural occurrence and variability of ambulatory arrhythmias permits appropriate choice and timing of antiarrhythmic therapy.

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.

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.

The normal posterior aortic wall echocardiogram shows anterior motion during left ventricular systole and predominantly posterior motion in three phases during left ventricular diastole. In six patients undergoing simultaneous left atrial angiograms and posterior aortic wall echocardiograms, there was excellent correlation between the posterior aortic wall motion and the change in the left atrial angiographic area showing the value of the posterior aortic wall echocardiogram in describing the left atrial volume curve. Left atrial and left ventricular pressures were measured with manometer tip catheters and correlated with simultaneous posterior aortic wall and mitral valve echocardiograms in four patients with atrial septal defects. These echocardiographic, angiographic, and hemodynamic correlations, as well as other evidence reported in this paper suggest that a major portion of posterior aortic wall motion is related to left atrial events and describes the left atrial volume curve.

A 5 week study was performed in 17 patients with frequent ventricular ectopic complexes. The study design comprised an initial control period, 1 week each of treatment with propranolol (240 mg daily), procainamide (3.0 g daily) and quinidine (1.8 g daily) and a final control period. Twenty-four hour ambulatory electrocardiograms and maximal exercise tests were performed each week. For the group, the total number and qualitative types of ventricular ectopic complexes were similar during the two control periods; however, there were large variations among individual patients. Each drug reduced the total number of ventricular ectopic impulses and the percent of patients with each qualitative type. There was agreement between the ambulatory electrocardiogram and treadmill test in three quarters of the drug evaluations. Although it is possible to determine antiarrhythmic drug effects for a group, spontaneous variability in the occurrence of ventricular arrhythmias makes it difficult to evaluate the effects in individual patients.

Eleven consecutive patients with recurrent ventricular arrhythmias were treated by an aggressive protocol and followed up prospectively. Arrhythmias, symptoms, and cardiac lesions were defined. Antiarrhythmic drugs were given on schedule, with blood levels determining dose; success or failure was defined by elimination or recurrence of symptomatic arrhythmias. When drug therapy failed, left ventricular aneurysmectomy was done when appropriate. Recurrent ventricular tachycardia was most frequently responsible for symptoms; coronary artery disease was the most frequent underlying disease. Symptomatic arrhythmias were eliminated in 8 of 11 patients (5 with drugs and 3 with aneurysmectomies), with a 16.5-month symptom-free average follow-up. An average of 2.9 therapeutic trials per patient was needed to control symptomatic arrhythmias. The average time from entry into the study until the start of ultimately effective therapy was 18 days. Therapy that eliminated symptoms did not eliminate all premature ventricular contractions, and occasionally even brief asymptomatic episodes of ventricular tachycardia persisted. Recurrent symptomatic ventricular arrhythmias can be controlled in many patients by rigorous application of current therapies.

Arylsulfatase was released almost completely from intact cells of Pseudomonas C12B after osmotic shock or after treatment with lysozyme. These results suggest that the enzyme is cell wall associated in this soil isolate.

White bands resulting from precipitation of dodecan-1-ol liberated by hydrolysis of sodium dodecyl sulfate and decan-5-ol released by hydrolysis of decan-5-yl sulfate produced zymograms of the primary and secondary alkylsulfatases from Pseudomonas C(12)B. Gas-liquid chromatographic analyses of ether extracts of the precipitate-containing segments of the zymograms confirmed the identity of the alcohols which were not discerned in extracts of segments of the gels other than those containing precipitates. beta-Galactosidase from Escherichia coli was marked on zymograms by the liberation of o-nitrophenol from o-nitrophenyl-beta-D-galactoside, and arylsulfatase from Pseudomonas C(12)B was marked in gels by liberation of p-nitrophenol from p-nitrophenyl sulfate. Membrane-associated dissimilatory nitrate reductases from a nitrate respirer (Enterobacter aerogenes) and a denitrifier (Pseudomonas perfectomarinus) did not penetrate either 6.8 or 3% polyacrylamide gel but were demonstrable at the top of the gels. In the membrane-bound state, formate served as electron donor for nitrate reductase from E. aerogenes, and reduced nicotinamide adenine dinucleotide (NADH) served as donor for nitrate reductase from P. perfectomarinus. Both enzymes reduced nitrate at the expense of reduced benzyl viologen as well. Assimilatory nitrate reductase from E. aerogenes moved easily into the 6.8% gels (R(f) = 0.43 under the conditions of these experiments). The reduced dye served as electron donor for the assimilatory reductase, but formate and NADH did not. Incubation of the membrane-associated nitrate reductases with 2% Triton X-100 solubilized the enzymes and removed the capacity of formate and NADH to serve as electron donors. Both retained the ability to reduce nitrate at the expense of reduced benzyl viologen. The solubilized dissimilatory reductase from E. aerogenes moved further in the gels (R(f) = 0.49) than the soluble assimilatory reductase; the solubilized dissimilatory reductase from the denitrifier, P. perfectomarinus, moved further in the gels (R(f) = 0.64) than either of the enzymes from E. aerogenes.

The inspiratory diaphragmatic EMG was recorded via esophageal electrodes in six normal subjects. The EMG and ECG signals were analyzed by power density spectral analysis, before and after band-pass filtering (20--1,600 Hz). The EMG spectrum was concentrated in the bandwidth 25--250 Hz. Electrode motion introduced a significant artifact only at low frequencies. The ECG spectrum was also concentrated at lower frequencies, but substantial power from the cardiac signal spilled over across most of the EMG spectrum. Band-pass filtering was therefore effective in minimizing the former but not the latter. Of the various power and frequency parameters used to quantitate the EMG spectrum, the most stable was the centroid frequency. This was reproducible within and between subjects, and was not affected by changing tidal volume or inspiratory flow rate.

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.

Pseudomonas C(12)B and other Pseudomonas species released larger amounts of a (35)S-labelled metabolite into the medium when cultured on growth-limiting concentrations of Na(2)SO(4) as opposed to growth in SO(4) (2-)-sufficient media. The metabolite was found at all stages of the culture cycle of Pseudomonas C(12)B and maximum quantities occurred in stationary-phase culture supernatants. The metabolite was not detected when the bacterium was cultured on growth-limiting concentrations of potassium phosphate. The amount of the metabolite present in the medium greatly exceeded that which could be extracted from intact cells and, except for choline chloride, it was independent of the carbon source used for growth. If choline chloride was present in high concentration, then larger amounts of the metabolite were found in the culture medium. The metabolite was not detected extracellularly or intracellularly when the bacterium was grown in SO(4) (2-)-deficient media containing 5mm-l-cysteine. The same metabolite was also synthesized in vitro only when Pseudomonas C(12)B extracts were incubated with choline chloride, ATP, MgCl(2) and Na(2) (35)SO(4). The metabolite-forming system was not subject to repression by Na(2)SO(4) and was completely inhibited by 0.5mm-l-cysteine and activated by Na(2)SO(4) (up to 1.0mm). The metabolite was identified as choline O-sulphate by electrophoresis, chromatography and isotope-dilution analysis. Another (35)S-labelled metabolite was also detected in culture supernatants, but was not identified.