Leptospirosis in Latin America.

Leptospirosis is a common disease in Latin America. Transmission to humans occurs by contact with water or soil contaminated with the urine of rodents, dogs, or livestock. Pathogenesis is still poorly understood, and bacterial toxin or virulence factors are probably responsible for many features of the disease. The anicteric form is the most frequent presentation, and its clinical picture resembles influenza or other acute febrile diseases. Icterohemorrhagic leptospirosis, or Weil's syndrome, represents the severe form of the disease. Its clinical picture is similar to bacterial sepsis and multiple organ involvement occurs, mainly in kidneys and lungs, and causes great morbidity and mortality. Death is often related to multiple organ failure and pulmonary hemorrhages. Diagnosis is based on serology or blood, cerebrospinal fluid and urine cultures in specific media. Treatment involves a combination of antibiotics and supportive measures.

Parent behavioral training. An examination of the paradigm.

This article examines the parent behavioral training (PBT) paradigm as an important development in child treatment that emerged some two decades ago. Several points of evaluation in the paradigm are identified, and the recent literature has been reviewed to determine how well the paradigm has been empirically validated. Overall, PBT has been well validated as a model for bringing about therapeutic improvement in children and parents under certain conditions. The conditions are identified, as are needed areas of research.

Systolic and diastolic time intervals in the critically ill patient.

OBJECTIVE: The waveform of the first derivative of thoracic electrical bioimpedance was used to calculate systolic time intervals of the cardiac cycle, preejection period/left ventricular ejection time ratio, and diastolic time intervals, isovolumic relaxation period/filling time ratio. DESIGN: Prospective clinical study. Waveforms were examined from 913 normal and abnormal tracings from a thoracic electrical bioimpedance monitor. This monitor was coupled to a two-channel strip-chart recorder that identified preejection period/LV ejection time and isovolumic relaxation period/filling time in 86% of the tracings. SETTING: Two university-affiliated hospitals and one community hospital. PATIENTS: We assessed 100 subjects (ranging in age from 17 to 93 yrs) under various conditions. MEASUREMENTS AND MAIN RESULTS: Data from 15 normal subjects were used as a reference series to define normative values. Preejection period/left ventricular ejection time ratio was 0.35 +/- 0.1 (SD) and was consistent with data from systolic time intervals derived from simultaneous study of the ECG recording, carotid artery tracing, and phonocardiography. The diastolic time ratio (isovolumic relaxation period/filling time) was 0.4 +/- 0.2, in agreement with normal values derived by echocardiography and angiography. In a subgroup of 17 critically ill patients, a correlative study of simultaneously measured thoracic electrical bioimpedance, nuclear stethoscope, and radionuclide ventriculography was conducted. Systolic functions were compared by the ejection fraction derived by preejection period/left ventricular ejection time ratio displayed on the thoracic electrical bioimpedance monitor and by the radionuclide technique, and were found to be 57 +/- 13.8% and 58 +/- 8.6%, respectively (r2 = .49; y = 4.06x + 0.94; p less than .02; n = 17). Increased diastolic time ratios with normal or near-normal systolic time intervals were documented in nine (53%) of 17 critically ill patients with low systolic index. CONCLUSION: Both systolic and diastolic time intervals can be investigated noninvasively at the bedside by the thoracic electrical bioimpedance technique to provide a better understanding of left heart function.