Inhaled nitric oxide is not a myocardial depressant in a porcine model of heart failure

BACKGROUND: Inhaled nitric oxide has been shown to be a potent and selective pulmonary vasodilator. Reports of increases in left ventricular end-diastolic pressure and episodes of pulmonary edema during the clinical use of inhaled nitric oxide in patients with preexisting left ventricular dysfunction have raised concerns that this agent may have myocardial depressant effects. We therefore undertook a study of the effects of inhaled nitric oxide on myocardial contractility in a porcine model of ventricular failure and pulmonary hypertension. METHODS: After inducing heart failure in 10 pigs by rapid ventricular pacing, hemodynamic measurements and pressure-volume diagrams (by the conductance method) were obtained in six animals at baseline and during administration of inhaled nitric oxide at concentrations of 20 and 40 ppm. Myocardial contractile state was assessed by the end-systolic pressure-volume relationship and preload-recruitable stroke work, whereas diastolic function was measured in terms of the end-diastolic pressure-volume relationship and the pressure decay time constant T. RESULTS: Baseline hemodynamics reflected heart failure and pulmonary hypertension, and inhaled nitric oxide induced significant reductions in mean pulmonary artery pressure and pulmonary vascular resistance. Although left ventricular end-diastolic pressure increased during administration of inhaled nitric oxide, no changes were observed in measures of systolic or diastolic function. CONCLUSIONS: Inhaled nitric oxide reduced pulmonary vascular resistance but did not alter myocardial contractility or diastolic function. Increases in left ventricular end-diastolic pressure during inhaled nitric oxide therapy are therefore not due to myocardial depression and may be related to increases in volume delivery to the left side of the heart resulting from reduced pulmonary vascular resistance.     

Isolation of translactone-containing triterpenes with thrombin inhibitory activities from the leaves of Lantana camara

Methanolic extracts prepared from the leaves of Lantana camara have been found to inhibit human thrombin. An assay, in which thrombin activity is measured as a function of clot formation from fibrinogen, was used to guide the fractionation and purification of five principal active constituents (1-5), which were all characterized as 5,5-trans-fused cyclic lactone-containing euphane triterpenes.     

Enhancement of adenovirus-mediated gene transfer to human bone marrow cells

Adenovirus infection of CD34+ hematopoietic stem/progenitor cells is dependent on the multiplicity of infection (MOI), time of incubation, the volume in which the co-incubation occurs and the presence or absence of growth factors. Studies revealed that a brief co-incubation (1-8 hours), resulted in low levels of transgene expression, suggesting that adenovirus infection of CD34+ cells occurs slowly, and optimal transduction requires a 24 hour exposure to adenovirus. Infection by Ad/beta-gal or Ad/p53 at a MOI of 500:1 provided a high transduction efficiency but inhibited hematopoietic function. However, treatment at a MOI of 50-100 resulted in efficient transduction (10.7-15.7% positive) without detectable toxicity. Secondary proof of adenovirus transgene expression was demonstrated by detection of mRNA for p53 in Ad/p53 infected stem cells. We conclude that a 24 hour exposure to recombinant adenovirus encoding p53 or beta-gal, at a MOI of 50-100 is optimal for in vitro gene transfer to BM cells and has no significant effect on hematopoietic function. Adenovirus-mediated transduction of BM cells can also be modulated by growth factors (IL-3, GM-CSF and G-CSF) with improved gene delivery and maintenance of hematopoietic function. In summary, adenovirus vectors can be used to transiently transduce stem cells, and conditions have been defined to maximize expression and limit inhibitory effects on CD34+ cells. These data support continued investigation of this vector for local cytokine delivery and purging of stem cell products.     

Effect of ergotamine and ergonovine on plasma concentrations of thyroid hormones and cortisol in cattle

Plasma samples from two experiments were processed to determine whether ergot alkaloids associated with endophyte-infected tall fescue altered peripheral thyroxine (T4), triiodothyronine (T3), or cortisol concentrations in cattle. In Exp. 1, seven Angus steers (294 kg) received i.v. bolus injections of saline (SAL), ergonovine maleate (7 mg; EM), or ergotamine tartrate (7 mg; ET) at weekly intervals, and they received all treatments during the study. Blood was sampled every 15 min for 5 h, and treatments were given after h 1. Mean ambient temperature was 34 degrees C. Treatment x time affected plasma concentrations of T3 (P < .05) and of cortisol (P < .001) but not that of T4 (P > .2). Plasma T3 concentrations were not affected by SAL, whereas concentrations increased (P < .01) after either EM or ET treatment. Plasma cortisol concentrations were not altered by SAL or EM, but they were increased (P < .001) by ET treatment. In Exp. 2, six Holstein cows (499 kg) nursing calves received a bolus i.v. injection of SAL, EM (9.5 mg), or ET (9.5 mg) per estrous cycle, and all treatments were given over three cycles. Blood was sampled every 20 min for 5 h; treatments were given after h 1. Mean ambient temperature was 26 degrees C. Treatment x time affected T3 (P = .08) and cortisol (P < .001) and tended to influence (P = .16) T4 concentrations. Plasma T3, T4, and cortisol concentrations were not influenced by SAL treatment. Plasma T3 was higher (P < or = .01) after EM or ET treatment compared with pretreatment concentrations. Concentrations of T4 during the 4 h after EM and ET were increased (P < .001) compared with pretreatment. Plasma cortisol concentrations were not altered by EM but were increased (P < .001) by ET. Ergot alkaloids implicated as contributing agents to fescue toxicosis alter plasma concentrations of hormones important to metabolic and thermoregulatory functions in cattle.     

Clinical utility of the polymerase chain reaction in the diagnosis of extrapulmonary tuberculosis

This study examines the diagnostic utility of the polymerase chain reaction (PCR) in 156 patients (five human immunodeficiency virus (HIV) seropositive) suspected of extrapulmonary tuberculosis. The results of PCR in 226 samples from 11 different sites were compared with the results of microscopy and culture. Positive culture results were predicted in 86% of samples by PCR but in only 31% by microscopy. Specificity of PCR was 92%. In cases with culture-proven tuberculosis, PCR identified all 11 microscopy positive cases and 19 of 24 (79%) of the microscopy-negative cases. In four patients, PCR excluded the diagnosis of tuberculosis in microscopy-positive samples, which were later shown to contain mycobacteria other than Mycobacterium tuberculosis or laboratory contaminants. In 20 patients (microscopy, PCR and culture negative) a trial of antituberculous drugs was given, but patients showed no improvement and treatment was stopped. In 17 patients, all culture negative (in nine PCR was positive, three of whom also had positive microscopy) the diagnosis was probable tuberculosis based on clinical findings and response to treatment. This polymerase chain reaction has a much higher sensitivity than microscopy and can facilitate therapeutic decisions for those with suspected extrapulmonary tuberculosis.     

Effect of cation exchange on the distribution and movement of cations in soils with variable charge. I. Effect of lime on potassium and magnesium exchange equilibria

The influence of Ca(OH)₂ on K and Mg exchange equilibria in three New Zealand soils was studied. Calcium hydroxide was mixed with each soil to raise the pH to about 6 or 7. For each Ca(OH)₂ treatment, K and Mg exchange isotherms were determined, from which the equilibrium activity ratios were derived. Exchange coefficients and solution activity ratios were calculated according to the Gapon convention.The addition of Ca(OH)₂ produced varying effects in the Gapon exchange coefficient for both K and Mg. The magnitude and direction of change in the exchange coefficient were related to the cation initially dominating the exchange sites, rate of Ca(OH)₂ addition, soil colloids contributing to the CEC and specific interactions of Ca with these soil colloids.Addition of Ca(OH)₂ reduced the equilibrium activity ratio of all soils. Changes in the bonding strength of K and Mg with increasing CEC were suggested as a possible mechanism for this decrease.     

Polymer modification and synthesis using sulphenyl derivatives: 9. Addition of alkylsulphenyl chlorides to cis-1, 4-polybutadiene

Methanesulphenyl chloride and n-butanesulphenyl chloride add readily across the double bonds in cis-1,4-polybutadiene. The addition is highly regioselective so that long sequences of saturated units are formed. The products are very unstable, evolving hydrogen chloride on standing, but can be stabilized by replacing the labile chlorine atom with other nucleophiles in a phase transfer catalysed reaction.     

Brain mass estimation by head circumference and body mass methods in neonatal glycaemic modelling and control

Introduction

Hyperglycaemia is a common complication of stress and prematurity in extremely low-birth-weight infants. Model-based insulin therapy protocols have the ability to safely improve glycaemic control for this group. Estimating non-insulin-mediated brain glucose uptake by the central nervous system in these models is typically done using population-based body weight models, which may not be ideal.

Method

A head circumference-based model that separately treats small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) infants is compared to a body weight model in a retrospective analysis of 48 patients with a median birth weight of 750 g and median gestational age of 25 weeks. Estimated brain mass, model-based insulin sensitivity (S_I) profiles, and projected glycaemic control outcomes are investigated. SGA infants (5) are also analyzed as a separate cohort.

Results

Across the entire cohort, estimated brain mass deviated by a median 10% between models, with a per-patient median difference in S_I of 3.5%. For the SGA group, brain mass deviation was 42%, and per-patient S_I deviation 13.7%. In virtual trials, 87–93% of recommended insulin rates were equal or slightly reduced (Δ < 0.16 mU/h) under the head circumference method, while glycaemic control outcomes showed little change.

Conclusion

The results suggest that body weight methods are not as accurate as head circumference methods. Head circumference-based estimates may offer improved modelling accuracy and a small reduction in insulin administration, particularly for SGA infants.     

Ozone in the Laundry Industry—Practical Experiences in the United Kingdom

Since the early 1990s, the use of ozone in many commercial and industrial laundering applications has been evolving rapidly. Ozone allows washing to be conducted using cold water, thereby saving considerable heat energy and water consumption. Additionally, ozone enhances the wash process, resulting in a significant reduction in detergent dosage and number of rinses, thus saving water. Ozone/cold water cycles are gentler to fabrics, thus extending linen life. Finally, ozone/cold water laundering is beneficial for effluents, resulting in reductions in COD (chemical oxygen demand). Microorganisms are destroyed effectively in ozone-wash waters, and washing and drying cycles are shorter, thus saving labor. In this paper, the authors describe some specific case studies at commercial laundering installations in the UK, whereby the users of ozone have reaped major benefits, including enhanced microorganism kills/inactivation and significant cost savings.