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In epimastigotes of Trypanosoma cruzi, the etiological agent of Chagas' disease, arginine kinase activity increased continuously during the exponential phase of growth. A correlation between growth rate, enzyme-specific activity and enzyme protein was observed. Arginine kinase-specific activity, expressed as a function of enzyme protein, remains roughly constant up to 18 days of culture. In the whole range of the culture time mRNA levels showed minor changes indicating that the enzyme activity is post-transcriptionally regulated. Arginine kinase could be proposed as a modulator of energetic reserves under starvation stress condition.

Because it was recently suggested that pressure half-time (PHT) of aortic regurgitant velocity curve is influenced by heart rate (HR), we retrospectively analyzed 76 patients with aortic regurgitation (AR) to determine whether PHT independently correlates with HR and whether HR correction of PHT can be clinically useful. PHT correlated significantly (P < 0.001) with color Doppler relative regurgitant jet height (r = -0.62), with angiographic grading (r = -0.65), and with HR (r = -0.54); such correlations were confirmed by multivariate analysis. Tachycardia influences aortic velocity curve more than bradycardia, and this effect is more evident in patients with milder regurgitation. Two methods of HR correction of PHT were tested: relative PHT (PHT/diastolic time x 100) and corrected PHT (PHT/ radicalRR): only corrected PHT was independently related to both relative regurgitant jet height and angiographic grading (P < 0.001). HR correction of PHT by corrected PHT was of limited clinical usefulness: in fact, in the entire study population, the accuracy of the usual cutoff (< 300 msec) in detecting relevant AR was not improved by corrected PHT. However, in patients with higher HR (>/= 85 beats/min), in whom the effect of HR on aortic velocity curve appeared to be greater, corrected PHT was superior to PHT because the cutoff value of < 300 msec showed a good specificity (100%), a moderate sensitivity (66%), and a good accuracy (80%) in detecting relevant AR. Corrected PHT can be useful to confirm AR severity when a short PHT is observed in tachycardic patients.

The results of the exam at the light, the fluorescence and the scanning electron microscope of the endosperm of Melilotus alba mature impermeable seeds are reported. Cryostat sections, semithin sections and squashes are observed. Melilotus alba endosperm is variable in thickness and envelopes cotyledons and radicle. Its "aleurone" layer is one-cell thick, while the number of layers of its internal cells varies in relation to the location in the seed. In the aleurone cells, the cytoplasm and the outer portion of the wall are autofluorescent; tannic acid-ferric chloride stains the outer portion of the wall and allows to see clearly the inner thickenings, DAPI and haematoxylin demonstrate the presence of the nucleus. The cytoplasm of these cells is coloured by Sudan black b, and its fluorescence is enhanced by auramine and calcofluor white. Calcofluor white enhances the fluorescence of the outer portion of these walls, too, but is without effect on the non-autofluorescent thickening, indicating presence of cellulose only in the first case. Callose is absent. Also the thin autofluorescent walls of the endosperm inner cells react positively to calcofluor. These cells are very large, almost completely filled with "gelatinous" substances--the galactomannans--and very rarely contain a nucleus.

The authors have administered a test of intelligence (WAIS) and a test of attention (Color Naming) to a group of patients affected by chronic schizophrenic impairment. The scores give shape to a picture of mental deterioration, especially characterized by a decrease of attentive power. This results validates the possibility of a neuropsychological approach to the etiopatogenesis of schizophrenia and supports the hypothesis that an impairment of mental synthesis power may explain both clinical and psychometric features of the disease.

The authors have measured the correlation coefficient between W.B. and P.M. scores in 80 normal subjects, comparable for age and school. A mutual relationship between the two tests, connected by the hypothetical general intelligence factor "g", was really demonstrated. Correlation coefficient was positive and significative between W.B. total scores, excepted verbal scores, and P.M., the highest one between subtests 8, 9 and P.M. The intra-tests correlation between W.B. total scores and each subtest score was also evaluated: between sub-tests 8, 9 and W.B. total scores the highest one again. A new qualitative interpretation of mental deterioration in clinical neurology and psychiatry is suggested on the base of these results.

The plasma lipid and lipoprotein pattern (total cholesterol, triglycerides and total lipid concentration; electrophoretic separation of the lipoproteins) and plasma protein profile (total protein concentration; electrophoretic separation of the plasma proteins) have been determined in a group of 60 chronic schizophrenic patients (47 men and 13 women, mean age 30,3 +/- 22 years). When compared to a control group matched for age and sex, the schizophrenic patients exhibited significantly lower cholesterol concentration and altered distribution pattern of the plasma lipid fractions. Similarly, the plasma a1,- a2,- and beta-globulin patterns are also altered in schizophrenic group. It is concluded that the altered plasma lipid and protein patterns may suggest that (auto)-immunologic and/or metabolic factors may be involved in the pathogenesis of schizophrenic disease.