Critical Analysis of Dual-Probe Heat-Pulse Technique Applied to Measuring Thermal Diffusivity

The paper presents an analysis of the experimental parameters involved in application of the dual-probe heat pulse technique, followed by a critical review of methods for processing thermal response data (e.g., maximum detection and nonlinear least square regression) and the consequent obtainable uncertainty. Glycerol was selected as testing liquid, and its thermal diffusivity was evaluated over the temperature range from ??20 °C to 60 °C. In addition, Monte Carlo simulation was used to assess the uncertainty propagation for maximum detection. It was concluded that maximum detection approach to process thermal response data gives the closest results to the reference data inasmuch nonlinear regression results are affected by major uncertainties due to partial correlation between the evaluated parameters. Besides, the interpolation of temperature data with a polynomial to find the maximum leads to a systematic difference between measured and reference data, as put into evidence by the Monte Carlo simulations; through its correction, this systematic error can be reduced to a negligible value, about 0.8 %.     

Complete occlusion of the left main coronary artery and the importance of coronary collateral circulation

Study of four patients who survived complete occlusion of the left main coronary artery forms the basis of conclusions concerning the functional significance of coronary collateral circulation. Each of these patients had prominent collateral circulation from the right coronary artery. Global left ventricular function was maintained to the extent that congestive heart failure did not occur; the biplane ejection fraction was normal in the two patients where measurement was possible. The peak rate of systolic wall thickening by roentgen videometry in anterior left ventricular segments was normal in one patient and mild to moderately depressed in another. Experience with the patients described herein indicates that coronary collateral flow can provide critically needed circulatory support for the patient with coronary artery disease.     

Prevention of some complications of essential hypertension

The major reason for treating hypertension is to avoid complications of the disease as it affects "target organs." Treatment of the blood pressure is not the only way to avoid these complications, but it is part of the total practice of preventive medicine. Hypertension lasts for several decades in most patients, and there is time to destroy the patient through target organ effects or to save the patient through treatment. Diabetes, atherosclerosis, and other illnesses and operations pose special hazards to the patient with hypertension. Patients take many other drugs as well, and some of them react adversely with antihypertension medicines. Complications from blood pressure drugs involve nearly every organ system, more than most physicians can remember. These may be dose-related and can often be avoided by using smaller doses of more than one drug. Certain problems occur so frequently that they should be learned well. The physician should bear in mind that whatever develops may be due to the antihypertensive therapy. On the whole, however, medications for treatment of hypertension are remarkably safe and free from side effects.     

Factor analysis of measures of articulation, language, auditory processing, reading-spelling, and maxillofacial structure

Involvement of the mononuclear phagocyte system in the mechanism of resistance to Corynebacterium kutscheri was studied in C57B1/6 and Swiss Lynch mice. A major difference between the two mouse strains was that the phagocytic cells of the livers of C57B1/6 mice destroyed the bacteria with much greater efficiency. There was no evidence of serum factors which might have led to this greater bacterial killing observed in the C57B1/6 mice, and in vivo phagocytosis of C. kutscheri was identical in both mouse strains. Resistance to C. kutscheri could be transferred with spleen and/or bone marrow cells from resistant (Swiss Lynch X C57B1/6) F1 mice to 650-rad irradiated susceptible Swiss Lynch mice. Nonspecific and acquired mechanisms of resistance to C. kutscheri are discussed.     

Cardiac function in total anomalous pulmonary venous return before and after surgery

Cardiac performance was evaluated in 12 infants with isolated total anomalous pulmonary venous return. Four had significant pulmonary venous obstruction and severe pulmonary hypertension (group A). Eight had no obvious venous obstruction, and the pulmonary pressures were lower (group B). In all subjects, right ventricular end-diastolic volume was increased (197% of predicted normal) and its ejection fraction was normal. Left ventricular volume was, generally speaking, still in the normal range (87% of predicted normal); however, its ejection fraction was reduced (0.57 vs normal of 0.73) and left ventricular output was low (3.08 L/min/m2 vs normal of 3.98). Left atrial volume was consistently small (53% of predicted normal) with an appendage of normal size. The infants in group A had smaller chamber volumes/m2 BSA than those in group B. Left atrial function was abnormal, characterized by reduced reservoir function and a greater role as "conduit" from right atrium to left ventricle. Left atrial size was not found to be critical in the surgical repair of TAPVR. Cardiac function is restored to normal following surgery.     

Polymorphic variation in the amount of sialic acid attached to bovine transferrin

A "problem solving case" method of teaching practical pathology is described, illustrated and compared with more traditional teaching methods. This method offers many advantages-the most important being that it shows the effect of pathological lesions in an actual patient, thus emphasizing the relevance of pathology to clinical medicine. Other advantages are that self-assessmetn is encouraged; guidance is given on the depth of knowledge expected from a student; student response is favourable; no elaborate or expensive equipment is required; the method is economic in the use of staff time, and it is very flexible in use in terms both of time and place.     

Pathogenesis of nervous system lesions in epidemic parotitis in children

The authors studied antibodies to the nervous tissue in the blood (pair serum with an interval of 10 days) and in the CSF in 155 patients with epidemic parotitis and signs of neurotoxicosis, parotit meningitis and meningoencephalitis. Depending upon the intensivity of antibody elaboration 3 groups were distinguished. The first group (40 cases), with a high content of antibodies to the nervous tissue, was characterized by a prevalence of encephalitic forms (in 30 of the 40 cases). In the second group (32 cases) with a less antibody content there was a prevalence of meningitis, while meningoencephalitis was seen only in 3 cases. The third group (83 cases) with a low concentration or absence of antibodies was characterized by a mild course of the disease. This group included as well patients with neurotoxicosis. These data may indicate involvement of allergic mechanisms of a retarded type in the pathogenesis of remote lesions of the nervous system in epidemic parotitis.     

Mechanisms for oliguria in acute renal failure

Equations previously developed to describe the enterohepatic circulation of the major biliary bile acids in man (Gastroenterology 67:887, 1974) were modified in order to predict the effect on biliary bile acid composition and pattern of amino acid conjugation after prototypic perturbations of the enterohepatic circulation in man. For the steroid moiety, the effects of bile acid feeding, increased recycling frequency, decreased intestinal conservation, and increased dehydroxylation were simulated. For the glycine or taurine moiety, the effect of increased deconjugation or preferential loss of one of the amino acid moieties was simulated. For the steroid moiety, the steady state biliary bile acid composition reflects the balance between input and conservation for each bile acid. Similarly, the distribution of bile acids between glycine and taurine conjugates reflects the balance between conjugation and conservation for each amino acid moiety. Because these values may vary widely and independently, analysis of biliary bile acid composition in terms of the steroid moiety or the glycine-taurine ratio per se cannot be used to infer the relative rates of input or conjugation.