Utilization of nano-cryptomelane for the removal of cobalt, cesium and lead ions from multicomponent system: Kinetic and equilibrium studies.

Nano-cryptomelane was prepared and characterized using SEM with mapping, HRTEM, FT-IR spectra, thermal analysis and surface area. The diameter distribution of nano-cryptomelane was found to be 4-6 nm. Sorption performance of the prepared material was studied for the removal of Co2+, Cs+ and Pb2+ from a multi-system solution of equal molar ratio, 1:1:1. The sorption capacity of nano-cryptomelane was found to be 179.6, 442.6 and 716.9 mg/g for Co2+, Cs+ and Pb2+, respectively. The kinetic studies revealed that the sorption process obeys non-linear pseudo-second-order model and is controlled by an intra-particle diffusion mechanism. The equilibrium isotherm investigations outlined that the extended Langmuir isotherm model fits the data reasonably well and it is more applicable than Freundlich multicomponent sorption isotherm. The value of diffusion coefficient for the three metal ions is in the order 10-17 m2/s which indicates the chemisorption nature of the process. The desorption percentage attains the maximum value (98.13%, 97.29 and 97.04 for lead, cesium and cobalt ions, respectively) using 0.7 mol/L of HNO3. This revealed that nano-cryptomelane can be regenerated and reused for farther sorption of Pb2+, Cs+ and Co2+ from wastewater.

Pulmonary morphofunctional effects of acute myocardial infarction.

Acute myocardial infarction (AMI) may yield several respiratory changes. Nevertheless, no comprehensive pulmonary morphological/physiological correlation has been performed under this condition. The aims of the present investigation were: 1) to determine the respiratory parameters in an experimental model of coronary artery occlusion, 2) to relate these results to findings from lung histopathology, and 3) to evaluate the effects of propranolol used prior to AMI. Twenty-eight rats were anaesthetized and mechanically ventilated. In the control group (C), a suture line was passed around the left anterior descending coronary artery (LADCA). The infarct group (I) was similarly prepared but the LADCA was ligated and infarct resulted. In the control/propranolol (CP) and infarct/propranolol (IP) groups, propranolol was intravenously injected 5 min before surgery as performed in groups C and I, respectively. Lung static (EL,st) and dynamic (EL,dyn) elastances, airway resistance (RL,int), and viscoelastic/inhomogeneous pressure (deltaP2L) were determined before and 30, 60 and 120 min after surgery. In group I, EL,st, EL,dyn, RL,int and deltaP2L increased progressively throughout the experiment, and were higher than those found in groups C, CP and IP. All respiratory parameters but EL,st remained unaltered in group IP. Lung histopathological examination demonstrated alveolar, interstitial and intrabronchial oedema in group I. Group IP showed only interstitial oedema. Acute myocardial infarction yields lung resistive, elastic and viscoelastic changes. The last two results from alveolar and interstitial oedema, respectively. The previous use of propranolol diminishes respiratory changes.

[Anaerobic threshold detected using "V-slope analysis" in chronic chagasic disease]. / Limiar anaeróbio detectado pela "análise da curva-V" na cardiopatia chagásica crônica.

Anaerobic threshold (AT) as measured by V-slope, is the best parameter of cardiac reserve in patients with heart failure. A reduction of AT reflects linearly a limited cardiopulmonary reserve in patients with heart disease. We measured the anaerobic threshold from 28 patients (18 men; age 47 +/- 6.7 years) classified into four groups: IA (normal ECG, without heart disease; 9 patients); IB (normal ECG, early left ventricular segmental abnormalities; 5 patients); II (abnormal ECG, advanced myocardial damage, no signs of heart failure, 7 patients); and III (abnormal ECG, end-stage, congestive heart failure; 7 patients). The analysis of variance indicated that the anaerobic threshold from patients of group LA was significantly greater than in groups IB, II and III (p = 0.001). Tukeys multiple comparison test showed no significative differences between mean AT in groups IB, II and III. The present study clearly demonstrates that occurrence of initial left ventricular contraction abnormalities is associated with definite reduction of cardiopulmonary reserve, and that this reduction is progressive and parallels the hemodynamic alterations. The most probable cause of this finding in group IB is diastolic dysfunction as clearly shown in echocardiogram.

[The proliferative response of T cells against cruzipain in chronic chagasic cardiopathy]. / Reposta proliferativa das células T contra a cruzipaina na cardiopatia chagásica crônica.

In this paper, we sought to determine if chronic chagasic patients with cardiopathy could be distinguished from those displaying non-chagasic cardiopathy on the basis of T cell proliferative responses to cruzipain (GP57/51), a major antigen of T. cruzi. Assays were performed with peripheral blood mononuclear cells from 24 individuals classified as follows: normal donors (n = 8), patients with non-chagasic cardiopathy (n = 8), patients with chronic chagasic cardiopathy without morbid associations (n = 8). The analysis of variance indicated that the proliferative responses stimulated by cruzipain were significantly higher in the group of chagasic patients (p = 0.0001). Turkey's multiple comparison test showed that the proliferative index medium from normal and non-chagasic cardiopathy was not significantly different from each other. We conclude that the T cell responses against T. cruzipain, as measured by proliferative indices of cells found in peripheral blood, are exclusively associated with Chagas, disease. In view of the abundance of cruzipain antigen in amastigotes it is possible that these T cell specificities contribute to the heart tissue damage observed in chronic Chagas, disease patients.

Peripheral plasma met-enkephalin levels in ovulatory and anovulatory human menstrual cycles.

OBJECTIVE: To test the hypothesis that met-enkephalin has a role in human ovulation and that plasma levels may differ between ovulatory and anovulatory ovarian cycles. DESIGN: This is a descriptive study comparing levels of plasma met-enkephalin, gonadotropins, and ovarian steroids in 12 ultrasonically confirmed ovulatory cycles and 12 anovulatory cycles. SETTING: The study took place in the infertility clinic of a large teaching hospital receiving primary and tertiary referrals of both private and public sector patients. PATIENTS: All patients (n = 16) had infertility greater than or equal to 3 years and normal findings on previous investigation including evidence of ovulation. INTERVENTIONS: Ovarian cycles were defined using transabdominal ultrasound scanning. Biochemical analyses were by radioimmunoassay. MAIN OUTCOME MEASURES: The differences between plasma met-enkephalin levels in the two groups of cycles were compared. RESULTS: Met-enkephalin levels are significantly higher in ovulatory cycles with a significant peak in the 2 postovulatory days (Duncan's multiple range test; P less than 0.05). CONCLUSION: Human ovulation is associated with cyclic elevation of plasma met-enkephalin. Further studies are required to elucidate causality.

[Cineventriculography with radionuclides and intravenous dipyridamole in the prognostic evaluation after acute myocardial infarction]. / Cineventriculografia com radionuclídeos e dipiridamol venoso na avaliação prognóstica após infarto agudo do miocárdio.

PURPOSE: To evaluate safety and usefulness of dipyridamole-radionuclide ventriculography (D-RVG), soon after acute myocardial infarction (MI), in the prediction of future cardiac events. Traditionally performed tests were also compared. PATIENTS AND METHODS: Forty-one patients (4 females) with recent MI underwent rest and dipyridamole (0.58 mg/kg of body weight) radionuclide ventriculography. The criteria for a positive test for ischemia was failure to increase left ventricular ejection fraction in 0.05 from baseline value. All patients had also coronary angiography and 36 patients underwent thallium-201 scintigraphy for comparison. The mean follow-up was 16 +/- 3 months. The following findings were considered future for events: cardiac death, reinfarction, significant angina or heart failure. RESULTS: During the follow-up 18 of the 20 patients who had cardiac events had shown positive dipyridamole-RVG, as opposed to 5 of 21 event-free patients (p less than 0.01). The ventriculographic criteria for a positive test and dipyridamole left ventricular ejection fraction were the strongest predictors of those medical events (p less than 0.01 and p less than 0.001). Among the 36 patients who had thallium-201 imaging, 16 subsequently had cardiac events and the scans were positive in 82% (p less than 0.01). Twelve (29%) patients experienced reactions during dipyridamole infusion although no fatal complications were noted. CONCLUSION: Dipyridamole-RVG is relatively safe and a sensitive predictor of future cardiac events soon after acute MI, although additional experience is required before this new technique should be routinely recommended as an alternative approach.

Índices de contratilidade da fase isovolumétrica antes e depois do exercício isométrico em indivíduos normas e miocardiopatas / Contractility indices of isovolumetric phase before and after isometric exercise in normal and myocardial disease patients

Indices de contratilidade miocardica da fase isovolumetrica (pico dp/dt, Vpm, Vmax e dp/dt corrigida) foram medidos antes e depois de 2 minutos de exercicio sustentado do tipo "handgrip" em 23 pacientes, 10 sem miocardiopatia (grupo I) e 13 com miocardiopatia (grupo II). Os valores individuais dos dois grupos apresentaram uma certa superposicao.Durante o "handgrip" os indices de contrabilidade da fase isovolumetrica aumentaram nos pacientes normais mas, nao nos miocardiopatas, enquanto a pressao final do ventriculo esquerdo (PD2) aumentou significativamente nos pacientes do grupo II, mas, nao nos normais. A superposicao entre os indices dos grupos I e II tendeu a desaparecer durante o "handgrip", particularmente em relacao a Vmax, Vpm e dp/dt corrigida. Conclui-se que os indices de contrabilidade da fase isovolumetrica podem separar os normais de pacientes com miocardiopatia, se medidos antes e depois do "handgrip", especialmente se analisamos conjuntamente as alteracoes de Vmax e PD2

Myocardial enzyme activities in congestive cardiomyopathy.

A number of enzyme activities concerned with various catabolic pathways have been measured in biopsy specimens of the left ventricle in patients with congestive cardiomyopathy and compared with those in patients undergoing surgery for valvar or congenital heart disease. The myopathic patients showed a diminution in glycolytic capacity, in hexokinase activity and in the capacity to transfer reducing equivalents across the mitochondrial membrane.

Persistent atrial standstill.

The authors present a case of permanent atrial standstill with syncopal attacks, in a patient with chronic Chagas' Heart Disease. The recognition of this dysrhythmia was based upon the conventional and intracavity electrocardiographic tracings in addition to phonomecanographic and hemodynamic data. The recording of the His Bundle electrogram demonstrated the absence of atrial activity, with the His potential preceding all ventricular complexes and an advanced conduction defect distal to the bundle of His. A diffuse type of atrial involvement was suggested by the lack of response to pacemaker stimulation. An increase in ventricular rate following intravenous atropine administration, led to the diagnosis of an a-v junctional rhythm with a widened QRS complex due to an associated right bundle branch block. Following the implantation of an epicardial ventricular pacemaker, the patient became completely asymptomatic despite the persistence of electrical and mechanical atrial standstill.