Increased exhalation to inhalation ratio during breathing enhances high-frequency heart rate variability in healthy adults.

Heart rate variability (HRV) is a well-established surrogate of cardiac and emotional health that reflects the balance between sympathetic and parasympathetic activity of the autonomic nervous system. We examined the impact of manipulating exhalation to inhalation ratio (E:I) on HRV, without altering the intrinsic breathing rate of healthy individuals. We hypothesized that a longer exhalation relative to inhalation (E:I > 1) would shift HRV metrics in a direction consistent with increased parasympathetic activity. Twenty-eight individuals (16 young [6M, age = 21-28];12 older adults [6M, age = 66-80]) completed a task during which they paced breathing according to their intrinsic respiratory rate, but altered onset of exhalation and inhalation according to 1:1 sound cue (equal exhalation and inhalation duration) or 2:1 cue (exhalation twice as long as inhalation). Paced 1:1 breathing followed these task conditions to examine residual effects. Estimates of actual E:I ratio based on thoracic movement were 1.08(0.16) for 1:1 task and 1.33(0.20) for 2:1 task, which were significantly different from one another. HRV metrics derived from electrocardiogram included root mean square of the successive differences between normal heartbeats (RMSSD) and high-frequency (HF) HRV. Analyses of HRV metrics by block showed that RMSSD and HF-HRV were higher in the 2:1 task condition compared to 1:1. Time series analysis showed that HF-HRV increased after the end of the 2:1 task block and remained elevated for four minutes. These findings suggest that longer duration of exhalation relative to inhalation, without altering breathing rate, acutely increased RMSSD and HF-HRV, consistent with enhancement of cardiac vagal tone.

Differential carbohydrate metabolism conducts morphogenesis in embryogenic callus of Hevea brasiliensis (Müll. Arg.).

Somatic embryogenesis in Hevea is stimulated when the embryogenesis induction medium contains maltose, rather than glucose, fructose, or sucrose, in equimolarity (Blanc et al., 1999). Kinetic analyses were carried out on various physiological and biochemical indicators over the 8 weeks that the induction phase then expression of somatic embryogenesis can take. Embryogenesis induction in the presence of glucose, fructose or sucrose revealed strong callus growth in the first 3-4 weeks, associated with a high intra- and extracellular hexose content, a high starch content and a substantial decline in protein synthesis. In the presence of maltose, callus growth was slow and only half that seen with sucrose. This morphogenetic behaviour is associated with a drop in endogenous hexose and starch contents, and an increase in protein synthesis in the first three weeks of culture. The induction of embryogenesis in the presence of maltose was uniform and twice as fast as with sucrose supply. At the end of culture, peroxidase activity, antioxidant and membrane protein contents increased in these calluses; these characteristics may be associated with somatic embryo organization and with the maintenance of effective membrane integrity within a nutrient environment that has become limiting. These new results tally with data in the literature on the roles of sugars, and provide some precise information with regard to the 'carbohydrate deficit' hypothesis usually put forward to explain maltose action. An analysis of these results led to the hypothesis that regulation of endogenous hexose contents at a low level, through slow maltose hydrolysis, was a key element of the biochemical signal leading this callus towards somatic embryogenesis.

Corrected transposition of the great arteries with several associated anomalies in a 68-year-old patient.

Few patients with corrected transposition of the great arteries survive past 50 years of age because of the association with congenital defects, development of total atrioventricular block, and right ventricular dysfunction. We report the case of a male patient with dextrocardia in situs solitus and corrected transposition of the great arteries associated with a wide atrial septal defect and severe pulmonary valvar and subvalvar stenoses. The patient also developed a large aneurysm on the pulmonary artery, total atrioventricular block diagnosed 8 years earlier, symptoms of dysfunction of the systemic ventricle in the previous 2 years, insufficiency of the left atrioventricular valve, and aortic regurgitation. Despite all these associated anomalies, the patient developed class III cardiac decompensation only at the age of 68 years, which makes this case a rarity. The patient was clinically treated, and was discharged from the hospital in good condition.

Antifungal action of Hevea brasiliensis latex. Its effect in combination with fluconazole on Candida albicans growth.

Latex from Hevea brasiliensis and its subcellular fractions (L-serum and C-serum) were tested for antifungal activity alone or in combination with fluconazole. Candida albicans growth was inhibited with the same efficacy when yeasts were inoculated into culture medium supplemented over the total growth phase with latex as when latex was added during the exponential phase only: the minimum inhibitory concentration (MIC 80%) of H. brasiliensis latex was 123 micrograms protein ml-1. By means of a non-linear regression analysis of the experimental data, two distinct fixation sites for fluconazole (FCZ) could be determined: one of strong affinity (Kaff = 0.0162 microgram-1 protein ml) and another of low affinity (Kaff = 0.0071 microgram-1 protein ml). After addition of a mixture of FCZ and latex during the exponential phase, the affinity constant of yeasts for FCZ was calculated: when latex was in a final concentration of 21 micrograms protein ml-1 (Kaff = 1 microgram-1 protein ml) or 42 micrograms protein ml-1 (Kaff = 0.277 microgram-1 protein ml) and without latex (Kaff = 0.0502 microgram-1 protein ml). In two cases a synergistic effect between latex and FCZ was obtained. The highest efficacy was obtained with a latex concentration of 21 micrograms protein ml-1. The addition of subcellular fractions of latex, L-serum and C-serum, did not cause an antifungal effect. The indispensable role of rubber particles for raising an antifungal effect is demonstrated. Electron microscopy observations indicated a limited cell wall degradation and a high percentage of coagulated yeasts.

Pompe's disease or type IIa glycogenosis.

This is the report of a five-month-old child presenting clinical evidence of Pompe's disease: severe hypotonicity, hyporeflexia and congestive heart failure. The ECG showed a short PR interval, the chest radiography disclosed marked cardiomegaly, and the echocardiogram revealed marked left ventricular hypertrophy - the most typical finding of this disease. A skeletal muscle biopsy led to final diagnosis, because in the histopathologic study marked increased glycogen accumulation was evident. Death occurred two months after symptom onset.

[Treatment of membranous subaortic stenosis with balloon dilatation]. / Tratamento de estenose subaórtica em membrana por cateter balão.

PURPOSE: This study sought to evaluate the immediate and follow-up results of percutaneous balloon dilatation for the treatment of membranous subaortic stenoses. METHODS: Fourteen patients with mean age 11.4 +/- 5.2 years, were submitted to the procedure. They were selected when the echocardiogram showed a thin subaortic membrane that was far from the aortic valve, no fibro-muscular obstruction and only mild or moderate aortic regurgitation. After measuring the pressure gradient and analysis of the angiographic features, the balloon dilatation was made by applying a fast manual inflation until the balloon waist disappeared. The balloon diameter was the same as that of the outflow tract of left ventricle, immediately bellow the aortic valve. Pressure measurement, left ventriculogram and aortogram were repeated. Doppler echocardiogram was repeated in the following day, after 3 months and every 6 months thereafter. RESULTS: All 17 procedures were successful. The mean gradient was 76.1 +/- 21.2 mmHg before and 29.8 +/- 8.8 mmHg after dilatation (p < 0.01). There was no increase in aortic regurgitation or death after the procedure or during the follow-up. Twelve patients were discharged 24h after the procedure. Surgical treatment for femoral artery thrombosis was performed in 2 patients. In the follow-up of 33.3 +/- 23.6 months, 4 patients developed restenosis and 3 of them were submitted to successful redilatation. CONCLUSION: We conclude that in selected cases, the procedure is safe and effective, and restenosis may be treated by percutaneous balloon redilatation.

Tratamento de estenose subatória em membrana por cateter baläo / Ballon dilatation for the treatment of membranous subaortic stenosis

OBJETIVO - Avaliar os resultados imendiatos e a médio prazo de tratamento da estenose subaórtica em membrana através da dilataçÝo percutânea por cateter baläo. MÉTODOS - Os 14 pacientes, com idade média de 11,4ñ5,2 anos, foram selecionados pelo estudo ecodopplercardiográfico, mediante evidência de membrana subaórtica de fina espessura e distante das válvulas aórticas, ausência de componente muscular associado ou insuficiência aórtica (IAo) importante. Após a medida do gradiente e comprovaçÝo dos achados pela cineangiocardiografia, as dilataçöes eram feitas por insuflaçäo manual e rápida até o desaparecimento da constricçÝo do baläo. O diâmetro do baläo era no máximo igual ao da via de saída de ventrículo esquerdo, medida logo abaixo da valva aórtica. Manometria, ventriculografia esquerda era realizado no dia seguinte, após 3 meses e a cada 6 meses após o procedimento. RESULTADO - Os 17 procedimentos foram realizados com sucesso. O gradiente médio da amostra foi 76,1ñ21,1mmHg (41-115) pré dilataçäo e 29,8ñ8,8mmHg (13-45) pós dilataçäo (p menor que 0,01). Näo houve aumento do IAo pós procedimento. Doze pacientes receberam alta em 24h e 2 apresentaram oclusäo de artéria femoral, tratados cirurgicamente. Näo houve óbito imediato ou tardio. No acompanhamento de 33,3+23,6 meses (1-75) ocorreu reestenose em quatro pacientes, sendo três deles redilatados com sucesso. CONCLUSÄO - Em casos selecionados, o procedimento é seguro e eficaz e a ocorrência de reestenose pode ser tratada com nova dilataçäo percutânea.

The role of antegrade and collateral flow in relation to left ventricular function post-thrombolysis.

UNLABELLED: The aim of the study was to analyze the relationship between antegrade and collateral flow degree to the "culprit" coronary artery, and between both variables and left ventricular systolic function. We analyzed five hundred patients with acute myocardial infarction, treated prospectively and consecutively within 6 h of evolution with intravenous streptokinase. The degree of antegrade (0-3) and collateral blood flow (0-3) were correlated with 18 other variables. RESULTS: (a) By simple regression analysis, antegrade flow degree correlated positively (p < 0.0001), and collateral flow degree negatively (p = 0.0073) with left ventricular ejection fraction; (b) By multiple regression analysis, antegrade flow degree (p = 0.0032), but not collateral flow degree (p > 0.1), correlated independently with left ventricular ejection fraction; (c) In the subgroup of patients with occluded "culprit" coronary artery, the mean ejection fraction was significantly higher for those with collateral flow 3 (60.2% +/- 13.3 in relation to those with collateral flow < 3 (53.9% +/- 13.1, p = 0.032, 95% CI. 11.96 to (0.53%). In conclusion, antegrade coronary flow degree, but not collateral flow degree, correlated significantly and independently with left ventricular ejection fraction. However, in the subgroup of patients with occluded "culprit" coronary artery, collateral flow 3 led to better left ventricular systolic function, in relation to collateral flow < 3.

Transcatheter occlusion of patent ductus arteriosus using coil embolization.

We studied 31 procedures of coil embolization for occlusion of ductus arteriosus, attempted in 29 patients. The mean age was 4.8+/-3.4 years (1-16 years) and the mean diameter of ductus was 1.8+/-0.7 mm (0.8-3.1 mm). Femoral artery approach was used and aortogram in 90 degrees lateral view was performed. Through a Judkin right coronary catheter, the coil was delivered for occlusion of the ductus. In 5 cases, 2 coils were delivered using retrograde and anterograde techniques. Successful placement of coil was accomplished in 29 procedures. Coils 0.038 inch (diameter)-5 cm (length)-5 mm (helical diameter) (Cook, Inc) were used in 16 procedures, coils 0.035 inch-5 cm-5 mm in 9, coil 0.038 inch-8 cm-8 mm in 1, two coils 0.038 inch-5 cm-5 mm in 2, coils 0.038 inch-5 cm-5 mm+0.038 inch-5 cm-8 mm in 1, and 2 coils 0.035 inch-5 cm-5 mm in 2. Aortogram 20 min after the occlusion, showed residual shunt in 9. Coil migration occurred in a ductus type B in the following day. One patient developed severe haemolysis, due to a change in the coil position, 12 h after the procedure. Echodopplercardiogram 4 to 6 h after the procedure showed a residual shunt in 5 patients, 24 h after in 3 and 30 days after, in 1(3.8%). Heparin therapy started 10 days after occlusion of the ductus, caused reappearance of the shunt in 1 patient. This technique is simple and effective, but complications may occur hours or days after successful ductus occlusion.

Purification and Characterization of Phosphoribosylpyrophosphate Synthetase from Rubber Tree Latex.

Phosphoribosylpyrophosphate synthetase (PRS; EC 2.7.6.1) from Hevea brasiliensis Mull. Arg. latex was located in the cytosol. After purification, its apparent molecular weight under nondenaturing conditions was estimated at 200,000 [plus or minus] 10,000; a single band at 57,000 [plus or minus] 3,000 was detected after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme seemed to be a homotetramer. Its affinity constants were estimated at 200 [plus or minus] 30 [mu]M for adenosine triphosphate and 40 [plus or minus] 2 [mu]M for ribose-5-phosphate. The purified enzyme proved to be functional in a paraphysiological medium (cytosol deproteinized by ultrafiltration). Optimum pH was 7.5 in buffer and 6.5 in a paraphysiological medium. No PRS activity was detected in the absence of the Mg2+ ion. Of the numerous compounds tested, only Mn2+, phosphoribosylpyrophosphate, and inorganic phosphate affected the enzymatic reaction. Mn2+ (inhibitor constant = 20 [mu]M) and phosphoribosylpyrophosphate (inhibitor constant = 30 [mu]M) were inhibitors. PRS responded allosterically (Hill's coefficient = 2.3) to ribulose-5-phosphate in the presence of a physiological concentration of inorganic phosphate (10 mM). These results are set in the physiological context of laticifers.

Latex allergy: allergen identification in Hevea braziliensis fractions by immunoblotting.

BACKGROUND: Latex is the cause of several clinical symptoms of allergy, but the identification of allergens is not completely known. OBJECTIVE: The aim of this report was to study the immunoreactivity of purified stable latex fractions from Hevea braziliensis. METHODS: We purified the cytoplasm of Hevea braziliensis and obtained three fractions: latex particles (LP), lutoids (L) and cytosolic serum (CS). Using Western blot, specific IgE directed to latex allergens was found in 80 patients with latex allergy. RESULTS: Five major groups of allergens migrating as 14, 25, 29, 37-45 and 50 kDa were recognized. They were unequally distributed with the latex fractions: 37-45 kDa proteins were essentially recognized in CS and LP, whereas 14 and 29 kDa proteins were mainly labelled in the L fraction. As a control, aqueous glove extracts exhibited a more restricted pattern of reactivity, because only 14 and 29 kDa proteins were recognized by patient sera. The pattern of reactivity was not correlated specifically with IgE levels, but sera from patients suffering from spina bifida reacted specifically with the minor protein of 25 kDa located in LP. CONCLUSIONS: The present results show that latex allergic patients recognize several allergens which are differently distributed in subcellular fractions extracted from H. braziliensis and aqueous GE. The L fraction and GE were enriched in low molecular weight proteins and apparently contained the same allergens.

On- and off-responses in the photopic electroretinogram in complete-type congenital stationary night blindness.

We examined the on- and off-responses of the photopic electroretinogram in patients with complete congenital stationary night blindness. Standard flash electroretinograms as well as those produced in a ganzfeld modified for long-duration light stimuli (500 msec) permitted the separation of on- and off-responses in four patients and four normal subjects. The amplitude and latency of the elctroretinogram on-response (a- and b-waves) and off-response (d-wave) in addition to the oscillatory potentials of the off-response in normal subjects and patients were compared. The abnormal on-response was demonstrated in all the patients, and the off-response with its oscillatory potentials were preserved. We showed that the second portion of the off-response (of inner retinal origin) is normal. If congenital stationary night blindness is a defect of depolarizing bipolar cells, these results preclude input of the depolarizing bipolar cells and support the hyperpolarizing bipolar cells as the cellular origin of the off-response electroretinogram.