In vitro evaluation of the apical seal of two different retrograde filling materials

To determine whether the selection of retrograde filling material or the choice of instruments in root tip resection influences the seal of the retrograde root filling. Seventy-two single-rooted teeth were used. Root resection was performed using a Lindemann bone cutter, a Lindemann bone cutter with A-shaped cutting design or a diamond-coated bur. Retro-cavities were prepared by piezo-tips and filled with Super-EBA or MTA. Teeth were made transparent and dye penetration was assessed. Teeth filled with MTA, irrespective of the resection instrument, showed no measurable dye penetration. All groups filled with Super-EBA showed an apical leakage. There were no significant differences between the three groups filled with Super-EBA (P = 0.09). The comparison of MTA versus Super-EBA showed significant superiority in apical seal in favour of MTA (P < 0.0001). To use MTA as a retrograde filling material showed superior results in terms of the tightness of the apical seal as compared to Super-EBA.

Will Culling White-Tailed Deer Prevent Lyme Disease?

White-tailed deer play an important role in the ecology of Lyme disease. In the United States, where the incidence and geographic range of Lyme disease continue to increase, reduction of white-tailed deer populations has been proposed as a means of preventing human illness. The effectiveness of this politically sensitive prevention method is poorly understood. We summarize and evaluate available evidence regarding the effect of deer reduction on vector tick abundance and human disease incidence. Elimination of deer from islands and other isolated settings can have a substantial impact on the reproduction of blacklegged ticks, while reduction short of complete elimination has yielded mixed results. To date, most studies have been conducted in ecologic situations that are not representative to the vast majority of areas with high human Lyme disease risk. Robust evidence linking deer control to reduced human Lyme disease risk is lacking. Currently, there is insufficient evidence to recommend deer population reduction as a Lyme disease prevention measure, except in specific ecologic circumstances.

[The Common Risk Factor Approach - An Integrated Population- and Evidence-Based Approach for Reducing Social Inequalities in Oral Health]

Worldwide, non-communicable diseases including dental caries and periodontal diseases, remain a major public health problem. Moreover, there is a social gradient in health across society that runs from the top to the bottom in a linear, stepwise fashion. Health promoting behaviours become more difficult to sustain further down the social ladder. Oral health inequalities also exist in Germany. Earlier explanations of social inequalities have mainly focused on individual lifestyle factors, ignoring the broader social determinants of health and disease. Until recently, the dominant approaches to general health promotion focused on actions to reduce specific diseases, separating oral health from general health. An alternative approach is the common risk factor approach (CRFA) where risk factors common to a number of major chronic diseases, including diseases of the mouth and teeth, are tackled. The CRFA focuses on the common underlying determinants of health to improve the overall health of populations, thereby reducing social inequalities. The main implication of the CRFA for oral health policies is to work in partnership with a range of other sectors and disciplines. Oral health issues need to be integrated with recommendations to promote general health. Improvements in oral health and a reduction in oral health inequalities are more likely by working in partnership across sectors and disciplines using strategies that focus upstream on the underlying determinants of oral diseases.

COMPARAÇÃO ENTRE SISTEMAS DE AVALIAÇÃO AMBIENTAL EM GALPÕES DE GALINHAS POEDEIRAS NA REGIÃO DE DOURADOS – MS

Considerando que fatores ambientais como temperatura e umidade influenciam na produção animal, estes devem ser observados com o máximo de precisão possível, para assim, evitar tomadas de decisões baseadas em dados distorcidos. Desta forma, o objetivo deste trabalho foi coletar dados climáticos próximos a um galpão para produção de galinhas poedeiras e compará-los com os medidos por uma agência meteorológica oficial, verificando possíveis desvios devido à distância geográfica existente. O experimento foi realizado na cidade de Dourados – MS, com coletas de dados climáticos na UFGD e Embrapa Agropecuária Oeste, em abril de 2014. Foram escolhidos 8 dias aleatórios, onde se leu a temperatura, velocidade do vento e umidade relativa do ar. Por meio dos valores médios do índice de temperatura e umidade (ITU) obtidos para o galpão e dados oficiais foi possível concluir que a curva de ITU adquirida para a agencia climática oficial representa uma curva ideal para a realidade local de Dourados-MS, porém seus dados não representaram a situação local medida in loco no horário mais quente do dia.

Randomized controlled trial on the efficacy of new alcohol-free chlorhexidine mouthrinses after 8 weeks

OBJECTIVES

To evaluate the efficacy of two alcohol-free antimicrobial mouthrinses in reducing plaque and gingivitis compared to an alcohol-containing rinse and toothbrushing alone.

METHODS

One hundred and sixty healthy volunteers were enrolled in the randomized controlled trial. Participants were randomly and equally assigned to four groups: (i) toothbrushing + rinsing (0.06% CHX + 0.025% NaF, alcohol-containing rinse, positive control); (ii) toothbrushing + rinsing (0.06% CHX + 0.025% NaF, alcohol-free experimental rinse); (iii) toothbrushing + rinsing (0.06% CHX + 0.03% CPC + 0.025% NaF, alcohol-free experimental rinse); (iv) toothbrushing alone (negative control). At baseline, Quigley-Hein plaque index (QHI), modified proximal plaque index (MPPI), and papillary bleeding index (PBI) were recorded. All subjects brushed their teeth as usual during the study. Additionally, groups 1-3 rinsed twice daily. Eight weeks after baseline, indices were recorded again. anova with Bonferroni adjustment served for statistical analysis.

RESULTS

One hundred and fifty-five participants were included into final analysis (i: n = 39, 2: n = 39, 3: n = 37, 4: n = 40). Experimental rinses (ii, iii) reduced QHI and MPPI to a higher extent than the negative control (iv), whereas no significant difference to the positive control was found. QHI: (i) 36.6%, (ii) 32.3%, (iii) 36.8%, (iv) 21.6%; MPPI: (i) 11.9%, (ii) 12.2%, (iii) 13.6%, (iv) 3.5%. For PBI, no statistically significant difference was found between groups: (i) 80.2%, (ii) 77.8%, (iii) 76.5% and (iv) 78.8%.

CONCLUSIONS

With respect to QHI and MPPI, toothbrushing in combination with any rinse was more effective than toothbrushing alone. No statistically significant differences were found between the alcohol-free and the alcohol-containing control rinses.

SISTEMA INTENSIVO DE CRIAÇÃO DE PEIXE COM RECIRCULAÇÃO DE ÁGUA E CONTROLE DE TEMPERATURA VIA BOMBA DE CALOR DE DUPLO EFEITO TÉRMICO

Este trabalho apresenta os resultados de um sistema piloto de criação intensiva de peixes com recirculação de água, onde foram avaliadas as criações de tilápias e trutas. As tilápias e as trutas foram criadas em tanques com controle de temperatura da água, mantidas em 28 ± 1 ºC e 15 ± 1 ºC, respectivamente, empregando uma bomba de calor de duplo efeito térmico para provimento da demanda de aquecimento e resfriamento da água. Na criação de tilápias vermelhas e da variedade tailandesa a conversão alimentar aparente foi de 1,37:1 e 1,16:1, respectivamente. As trutas apresentaram boa adaptação ao confinamento, obtendo um ganho de peso de 500% em 18 semanas. A taxa diária de renovação de água nos tanques foi de 5%. A produtividade estimada para a criação intensiva de tilápias tailandesas foi de 150 t ha-1. O arranjo empregado apresentou resultados satisfatórios, bem como, a bomba de calor mostrou-se eficaz e confiável, entretanto, novas formas e tecnologias devem ser estudadas para a remoção da amônia gerada, que mostrou ser o maior gargalo deste tipo de sistema.

Effects of Bleaching Agents on Human Enamel Light Reflectance

In dental bleaching, the micromorphological alterations of hard tissues have been well investigated, but little is known about the optical changes involved. The results of the current study showed that enamel, irrespective of maturation, is subjected to a shift in reflectance towards blue within the color space and enhanced reflection. This effect was demonstrated in different bleaching agent concentrations and protocols.

Mechanistic toxicogenomic analysis of WAY-144122 administration in Sprague–Dawley rats

Application of global gene expression analysis in the study of mechanisms of toxicity could provide a more comprehensive interpretation of the molecular basis of drug action. WAY-144122 has pharmacological activity against several targets improving insulin responsiveness and favorably altering lipid profiles. Normal rats treated with suprapharmacological doses of WAY-144122 for 28 days exhibited drug-related effects in the liver and ovary. To determine the molecular mechanism underlying these effects, we employed global gene expression profiling to measure RNA levels in these target organs obtained from WAY-144122-treated rats administered test article for 1, 3, 7, and 14 days. Genes altered in expression by WAY-144122 were functionally categorized and related to their biological activity. In the liver, WAY-144122 caused a widespread up-regulation of genes involved in lipid mobilization, peroxisomal proliferation, and fatty acid beta-oxidation. In the ovary, we observed reduced expression of genes encoding luteinizing hormone receptor, follistatin, and enzymes in the estradiol synthesis pathway. Transcriptional changes in both organs precede histopathological effects. Profiling analysis allowed us to formulate hypotheses for molecular mechanisms underlying the physiological observations. In the liver, transcriptional changes suggest that WAY-144122 induced increased metabolic activity and peroxisomal proliferation resulting in increased liver weight and hepatocellular hypertrophy. We propose decreased estradiol synthesis as the underlying mechanism for the observed follicular atrophy in the ovary. Importantly, in this study, we have identified potential molecular mechanisms of drug effect in expression profiles before observation of physiological changes.

Lipoteichoic acid inhibits interleukin-2 (IL-2) function by direct binding to IL-2

Lipoteichoic acid (LTA) is associated with the cell envelope of most gram-positive bacteria. Although previously thought to act mainly as a virulence factor by virtue of its adhesive nature, evidence is now provided that LTA can also suppress the function of interleukin-2 (IL-2), an autocrine growth factor for T cells. LTA from four separate bacterial strains lowered the levels of detectable IL-2 during a peripheral blood mononuclear cell response to the antigen tetanus toxoid (TT). T-cell proliferation in response to TT was similarly inhibited by LTA. In contrast, levels of detectable gamma interferon increased. In addition, LTA inhibited IL-2 detection by enzyme-linked immunosorbent assay (ELISA) and blocked the proliferative response of an IL-2-dependent T-cell line to soluble IL-2. Further studies using ELISA demonstrated that LTA blocks IL-2 detection and function by binding directly to IL-2. Flow cytometric analysis revealed that IL-2 binding to T cells is inhibited in the presence of purified LTA but not LTA plus anti-LTA monoclonal antibody. In summary, these studies demonstrate a novel effect of LTA on the immune response through direct binding to IL-2 and inhibition of IL-2 function. Importantly, gram-positive organisms from which LTA is obtained not only play an important role in the pathology of diseases such as bacterial endocarditis, septic shock, acute respiratory distress syndrome, and multiple organ failure but also comprise a significant portion of commensal populations within the human host. Inhibition of IL-2 function by LTA may represent yet another mechanism by which gram-positive bacteria dampen the host immune response and facilitate survival. Thus, LTA provides a potential target for therapeutic intervention when gram-positive organisms are involved.

Effects of habitat structure on the retention of Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) adults during drag sampling surveys

The ability of Ixodes scapularis Say and Amblyomma americanum (L.) to remain on drags, once acquired, was tested in sparse and dense shrub layer vegetation. When placed on bottoms of drags, adults of both species remained attached for distances three to four times greater in sparse vegetation compared with dense vegetation. When attached to the tops of drags, the differences in retention of ticks on drags between vegetation densities were significant only for A. americanum. In dense vegetation, drags should be checked at 10-m intervals, whereas in sparse vegetation this distance can be extended to 20 m without significant loss of acquired ticks.

Efficacy of granular deltamethrin against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidade) nymphs

A single barrier application of granular deltamethrin to the woodland edges of a forested residential community in late spring significantly reduced the abundance of Ixodes scapularis Say nymphs. The application also suppressed the population of Amblyomma americanum (L.) nymphs, which recently became established in the study area. The efficacy of deltamethrin is compared with other commonly used acaricides.

Effects of selected meterological factors on diurnal questing of Ixodes scapularis and Amblyomma Americanum (Acari: Ixodidade)

The diurnal questing behavior of adult Ixodes scapularis Say and Amblyomma americanum (L.) were monitored in the field to determine whether ticks would be collected with greater frequency during certain times of the day and under certain ambient meteorological conditions. Temperature and relative humidity explained a significant amount of the total variation in tick collections. Although both species were collected during every period, I. scapularis adults tended to quest earlier and later in the day when temperatures were lower and relative humidity higher, whereas A. americanum were collected with greater frequency in late morning and early afternoon during periods of higher temperatures and lower humidity. Questing of I. scapularis adults was observed at temperatures as low as -0.6 degrees C, whereas no adult A. americanum were collected below 4.4 degrees C. The questing temperature threshold for I. scapularis adults observed in this study was below that reported previously. The implications of these temporal activity patterns on the assessment of disease transmission risk and sampling bias are also discussed.

Effects of an application of granular carbaryl on nontarget forest floor arthropods

We evaluated the effects of a single application of granular carbaryl made against nymphal Ixodes scapularis Say on the diversity and abundance of forest arthropods taken in pitfall traps in oak and mixed oak-pine forest sites for 12 wk after treatment in central New Jersey. Significant short-term changes in arthropod assemblages were detected immediately posttreatment. Effects were not distributed equally across taxa. Seasonal changes in numbers and diversity of forest arthropods in the study areas may have affected the impact of the acaricide in the treatment area. Comparison with control areas indicated that reductions in abundance of some arthropod taxa in the treatment area were detectable 12 wk after treatment.

Effects of granular carbaryl application on sympatric populations of Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) nymphs

A single application of granular carbaryl approaching the lowest recommended rate to the shrub layer of a forested area in late spring significantly reduced the abundance of Ixodes scapularis Say nymphs throughout their peak activity period, but had little effect on Amblyomma americanum L. nymphs. Factors influencing the efficacy of the application are discussed. The possible explanations for the lack of efficacy of granular carbaryl against A. americanum, including behavior, formulation, and application rate, are discussed.

Comparison of Ixodes scapularis (Acari: Ixodidae) populations and their habitats in established and emerging Lyme disease areas in New Jersey

Hunterdon Country, New Jersey, experienced a significant increase in the number of Lyme disease cases during 1990-1995, accounting for 21.2% of all New Jersey cases. This study compares the relative abundance of Ixodes scapularis Say in similar habitats in Hunterdon County, an emerging Lyme disease area, and Monmouth County, where Lyme disease has been established for well over a decade. The extent to which differences in habitat physiognomy could explain differences in tick populations, and consequently Lyme disease case rates, is addressed. Ticks were surveyed and vegetation measurements made in 4 habitat types at 1 site in each county. I. scapularis was 7 times more abundant in Monmouth County than in the Hunterdon County site, and the distribution of all life stages among habitats differed significantly between sites. The greater numbers of subadult ticks at the Monmouth County site was attributed to greater shrub cover and litter depth which created more favorable microclimatic conditions for tick survival. However, the overall physiognomy of the different vegetation types at the sites studied in Monmouth and Hunterdon counties was remarkably similar and did not appear to explain differences in tick abundance. Until further research clarifies microscale differences between habitats, the differences in the case rates between the counties appear to be more likely the result of reporting artifact.

Biases associated with several sampling methods used to estimate abundance of Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae)

Several tick sampling methods were evaluated for ixodes scapularis Say and Amblyomma americanum (I.) in oak-dominated mixed hard-wood, pitch pine-dominated, and mixed hardwood and pine forests in coastal New Jersey. Walking surveys were more efficient for collecting I. scapularis adults than dragging by a factor of > 2:1. In contrast, drag sampling yielded nearly twice as many A. americanum adults compared with walking surveys. I. scapularis subadults were rarely collected during walking surveys. A. americanum nymphs were collected from drags approximately 3:1 over walking surveys. Twice as many A. americanum larvae were obtained from drags compared with walking surveys. All developmental stages of A. americanum responded positively to carbon dioxide. Pitfall traps and leaf litter samples collected very few ticks. Tick distribution among habitats varied significantly with the sampling method chosen, and the relative ranking of sites with respect to tick abundance varied depending on the stage of tick sampled. Failure to recognize the biases in these commonly used sampling techniques can potentially lead to incorrect conclusions that can have significant adverse public health consequences.

Seasonal and long-term variations in abundance of adult Ixodes scapularis (Acari:Ixodidae) in different coastal plain habitats of New Jersey

Fifteen sites in 4 different vegetation types in a Lyme disease endemic area were surveyed during times of peak tick activity in fall of 1982, 1984, and 1992, and subsequent spring activity periods to determine seasonal and year-to-year differences in habitat use by the blacklegged tick, Ixodes scapularis Say. Populations of I. scapularis adults varied significantly among the 3 yr surveyed, although this variability tended to be more pronounced in fall. I. scapularis adults were consistently more abundant in the fall than spring. Significant seasonal and year-to-year differences in adult populations were observed between and within vegetation types. However, the variability in habitat use was generally lower in spring compared with fall. In most of the surveys, the 5 sites yielding the greatest number of adults were represented by 3 or 4 of the vegetation types. Explanations for this variability and implications for tick surveillance and reducing risk of Lyme disease transmission are discussed.

Suppression of subadult Ixodes scapularis (Acari: Ixodidae) following removal of leaf litter

Removal of leaf litter in wooded areas of a forested residential community significantly reduced the abundance of questing blacklegged tick, Ixodes scapularis Say, nymphs throughout their peak activity period. Removal of leaf litter, using hand rakes and leaf blowers during the early spring (March) and early summer (June) resulted in reductions in nymphal tick density ranging from 72.7 to 100%. Subsequent sampling of the I. scapularis population during the summer revealed similar rates of suppression of larvae. Although leaf removal provides levels of suppression similar to more traditional methods, including chemical acaricides, it is labor intensive and not free of possible nontarget effects. The potential role of leaf litter removal in an integrated program to control I. scapularis is discussed.

Potential influence of leaf litter depth on effectiveness of granular carbaryl against subadult Ixodes scapularis (Acari: Ixodidae)

An application of carbaryl granules at the lowest recommended rate to the shrub layer of a forested residential community in late spring significantly reduced abundance of questing Ixodes scapularis Say nymphs throughout their peak activity period. Depth of leaf litter had no significant effect on the level of reduction, suggesting that granular carbaryl applied at relatively low rates can obviate the possible attenuating effects of leaf litter.

Suppression of Ixodes scapularis (Acari: Ixodidae) nymphs in a large residential community

To determine the feasibility of suppressing Ixodes scapularis Say populations in a large, hyperendemic residential community, several rates of granular carbaryl were applied by ground and air to the shrub layer and wooded buffers of a forested residential community during the peak activity period of nymphs. Granular carbaryl significantly reduced the abundance of I. scapularis nymphs on Peromyscus leucopus Raphinesque. Control nymphal ticks ranged between 70.0 and 90.3%. The use of properly timed acaricide applications to I. scapularis habitat within residential communities can provide an effective means of reducing exposure to I. scapularis nymphs, which are chiefly responsible for transmitting Borrelia burgdorferi to humans.

Postharvest quarantine disinfestation of zucchinis and rockmelons against Bactrocera cucumis (French) using insecticide dips of fenthion or dimethoate

The disinfestation efficacy of a 1-min dip in fenthion or dimethoate (400 mg/L in water) was tested against eggs and larvae of the cucumber fly, Bactrocera cucumis, in zucchinis and rockmelons. Each trial involved >30 000 individuals. Fenthion gave 100% mortality of eggs and third instar instar larvae in rockmelons, 100% mortality of eggs in zucchinis, and >99.99% mortality of third instar larvae in zucchinis. Dimethoate gave 100% mortality of eggs in zucchinis, >99.98% mortality of third instar larvae in zucchinis, and >99.99% mortality of eggs and larvae in rockmelons. Residues of fenthion and dimethoate in zucchinis or rockmelons were below the Australian maximum residue limit of 2 mg/kg on the day of treatment. There were no adverse effects on taste.

Cataracts in dogs following subchronic administration of the phenylpiperazine antihypertensive agent PD 78787

PD 78787, 3-[4-[4-(3-methylphenyl)-1-piperazinyl]butyl]-2,4-imidazolinedione, was an antihypertensive drug candidate with alpha 1 adrenoreceptor blockade identified as one of its pharmacologic activities. Beagle dogs were administered daily doses of 0, 1, 5, or 10 mg/kg for 41 weeks. During the study, periodic ophthalmic examinations were performed in addition to electrocardiography, blood pressure measurements, and hematological, clinical biochemical, and urinalysis assessments. At study termination, animals were euthanatized and the following procedures conducted; complete gross pathological examinations; histopathologic examination of lens; biochemical analysis of aqueous humor; and measurements of drug concentration in plasma, aqueous humor, and lens. Clinical signs observed included miosis, relaxed membrane nictitans, and somnolence. Ophthalmic examinations at Week 13 revealed unilateral posterior lenticular opacities at the dose of 10 mg/kg in two of four females. At Week 41, mature bilateral cataracts were observed in four of four females and three of four males administered the 10 mg/kg dose. The opacities appeared to develop from the posterior suture lines. No adverse effects on aqueous humor composition were observed. Significant concentrations of PD 78787 were found in lens and aqueous humor from all dose groups 24 hr following the last dose. These concentrations increased with increasing dose averaging 4 micrograms/ml in the lenses of dogs administered 10 mg/kg. Histopathologically, swelling, vacuolation, and dissolution of the lenticular fibers were observed at 10 mg/kg. All other study parameters were unaffected by drug treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Central ventilatory dysfunction in myelodysplasia: an independent determinant of survival

Central ventilatory dysfunction (CVD) is a significant complication of myelodysplasia with Arnold-Chiari type II defect. The records of 616 patients with myelodysplasia were reviewed and CVD was documented in 35 cases (5.7 per cent): it was the single most common cause of death in this population. There was no significant association between CVD and level of lesion, severity of hydrocephalus, hemorrhage or infection. The effects of CVD may be variable, with some patients having spontaneous remission and others having severe, often fatal, disruption of ventilation.

Basic concepts in drug metabolism: Part II

There are numerous articles available that provide a comprehensive review of basic concepts of drug metabolism. Our intent in this review article was to provide an overview of some of the basic pathways for drug metabolism, how they may be altered, and what influence they may have on drug therapy. Understanding metabolism should help to develop more effective and safer new drugs and to provide safer and more effective regimens for existing drugs. Although intersubject and intrasubject variability in pharmacokinetics is common, much of it may be explained by differences in metabolism.

Rapidly developing tolerance to transdermal nitroglycerin in congestive heart failure

We have reported early attenuation of hemodynamic effects of transdermal nitroglycerin in patients with heart failure. We now report nitroglycerin plasma levels in those same patients. We administered transdermal nitroglycerin, 60 mg/24 h, to eight patients or placebo to seven patients in a double-blind fashion, and monitored pulmonary wedge pressure and nitroglycerin plasma levels for 24 hours. After placebo administration, nitroglycerin plasma levels and pulmonary wedge pressure remained unchanged. During transdermal nitroglycerin administration, the plasma nitroglycerin level rose from 0.04 +/- 0.12 ng/mL at baseline to near peak levels at 2 hours (7.43 +/- 7.21 ng/mL). Between 2 and 24 hours, levels fluctuated at a steady state. Pulmonary wedge pressure fell from 22 +/- 7 mm Hg at control to a nadir of 14 +/- 5 mm Hg at 4 hours (p less than 0.01). Despite persistently high plasma nitroglycerin levels, by 18 hours pulmonary wedge pressure was no longer significantly reduced (20 +/- 9 mm Hg). These results indicate that rapid development of tolerance is the cause of attenuated hemodynamic efficacy of transdermal nitroglycerin.

Dose requirements and hemodynamic effects of transdermal nitroglycerin compared with placebo in patients with congestive heart failure

The dose requirements and duration of effect of transdermal nitroglycerin in patients with heart failure are not clearly established. In a first series of eight patients with chronic heart failure we gave transdermal nitroglycerin in incremental doses until pulmonary capillary wedge pressure fell at least 30% within 4 hr in three consecutive patients. Thus we found that a single dose of 60 mg/24 hr (120 cm2) was the minimal effective dose. Transdermal nitroglycerin or placebo was then given as a single application of 60 mg/24 hr in random double-blind fashion to 15 additional patients with heart failure (eight received transdermal nitroglycerin and seven received placebo), and hemodynamics were monitored for up to 24 hr. After administration of transdermal nitroglycerin, the control pulmonary capillary wedge pressure of 22 +/- 7 mm Hg fell by 6 +/- 6 mm Hg at 2 hr (p less than .05) and reached maximal reduction of 8 +/- 6 mm Hg (p less than .01) at 4 hr. The reduction in wedge pressure remained significant through 12 hr but was no longer statistically significant by 18 hr after administration of the drug. Transdermal nitroglycerin also significantly reduced pulmonary arterial and right atrial pressures as well as pulmonary vascular resistance from 4 through 12 hr but did not affect systemic hemodynamics. No significant hemodynamic changes occurred after administration of placebo. Thus transdermal nitroglycerin is an effective vasodilator in patients with heart failure, but a dose of at least 60 mg/24 hr is needed. Even with this dose, hemodynamic effects do not last beyond 18 hr, suggesting altered absorption or development of tolerance.

Effects of enalapril, a new angiotensin-converting enzyme inhibitor, in a controlled trial in heart failure

Angiotensin-converting enzyme inhibitors are effective vasodilators in the treatment of congestive heart failure. Enalapril, a new angiotensin-converting enzyme inhibitor, or placebo, in addition to digoxin and diuretic drugs, were given to 17 patients with chronic congestive heart failure who were followed up for 12 weeks. In random double-blind fashion, nine patients received enalapril and eight received placebo. Cardiac dimensions and function improved slightly but insignificantly in both groups. Treadmill exercise duration increased from a mean value (+/- standard deviation) of 9.1 +/- 3.2 to 12.0 +/- 3.5 minutes during enalapril administration (p less than 0.025) and was unchanged during placebo administration (10.1 +/- 3.7 versus 11.1 +/- 5.2 minutes). Maximal oxygen consumption also increased during enalapril therapy (15.8 +/- 3.4 to 18.4 +/- 4.4 ml/min per kg, p less than 0.05) and remained unchanged during placebo treatment (16.0 +/- 6.4 versus 17.0 +/- 4.6 ml/min per kg). Clinical functional class (Yale scale) improved 3.1 +/- 1.9 points (p less than 0.01) during enalapril treatment but not during placebo treatment (0.8 +/- 3.5 points, no significant difference). No significant side effects were observed. Thus, enalapril appears to be a clinically effective and useful new angiotensin-converting enzyme inhibitor for the management of chronic congestive heart failure.

Minoxidil in patients with chronic left heart failure: contrasting hemodynamic and clinical effects in a controlled trial

Minoxidil, a potent predominant arterial dilator, improves hemodynamics over the short term in patients with heart failure. In random double-blind fashion 17 patients with chronic left heart failure were given minoxidil (nine patients) or placebo (eight patients) in addition to digoxin and diuretics for 3 months. Cardiac index and heart rate increased and mean arterial pressure and systemic vascular resistance fell within 4 hr of minoxidil administration. Right heart and pulmonary arterial pressures were unchanged over the short term but rose after long-term minoxidil. After 3 months of minoxidil treatment, systemic vascular resistance was still reduced (11.7 +/- 6.3[SD] vs 17.1 +/- 3.1 U at baseline; p less than .05). Hemodynamics were similar at baseline and remained unchanged during placebo treatment. Mean left ventricular ejection fraction rose from 29.6 +/- 17.7% to 42.7 +/- 22.3% (p less than .05) after 3 months of minoxidil treatment (this result was influenced largely by responses in two patients), and remained unchanged (at 25.1 +/- 16.6%) after 3 months of placebo. Exercise duration and maximal oxygen uptake during exercise were unchanged during minoxidil or placebo treatment. Total clinical events, including increased need for diuretics, angina, ventricular arrhythmias, worsening heart failure, and death were all more frequent during minoxidil vs placebo administration (21 vs seven total events; p less than .01). Thus, despite improving hemodynamics and left ventricular function, long-term minoxidil administration was associated with a poorer clinical course in patients with chronic left ventricular failure. Furthermore, this experience demonstrates that improvement of left ventricular function alone cannot be reliably interpreted as proof of clinical efficacy of therapeutic interventions in patients with heart failure.

Relationship between malondialdehyde production and arachidonate consumption during NADPH-supported microsomal lipid peroxidation

Fatty acid concentrations and malondialdehyde formation were determined before and during NADPH-supported lipid peroxidation in liver microsomes from rat, mouse, guinea pig and rabbit. In agreement with earlier reports, malondialdehyde production was greatest for rat, followed by mouse, and much less for guinea pig and rabbit. The microsomal content of total unsaturated fatty acids (18:1, 18:2, 18:3, 20:3, 20:4, 20:5, 22:5, 22:6) was approximately the same for rat and mouse and was lower in guinea pig and rabbit. Lipid peroxidation caused a time-dependent decrease in the polyunsaturated fatty acids, particularly 20:4 and 22:6, for all species. These decreases were most pronounced for rat and mouse. Alterations in the dietary regime for rat produced marked changes in microsomal fatty acid content as reported by others, and also caused changes in the rates of malondialdehyde production and polyunsaturated fatty acid consumption during lipid peroxidation. A comparison between the rates of malondialdehyde production and the rates of individual unsaturated fatty acid consumption was performed for each animal species and for rats fed different diets. A linear relationship was found between malondialdehyde production and 20:4 disappearance in individual microsomal preparations and in different species. A similar relationship was seen for the initial microsomal concentration of 20:4 and the initial rate of malondialdehyde formation. Other unsaturated fatty acids did not exhibit linear relationships. Various microsomal mixed-function oxidase variables were measured for the different species. No direct relationship between these values and malondialdehyde production was found.