Tonin activity in rat saliva: effect of sympathomimetic and parasympathomimetic drugs

The effects of carbachol, propranolol and isoproterenol on tonin concentrations in rat saliva have been investigated. The results suggest that the activity of this enzyme in rat saliva is dependent on activity of beta-adrenergic receptors.

Evaluation of immunodiagnostic techniques for the detection of human hydatid cyst carriers in field studies

In a study of 662 sera from a hydatidosis endemic area, the indirect hemagglutination test based on a minimal nonspecificity criterion of positivity and the latex agglutination (LA) test were found to be suitable screening techniques for the detection of sera positive to the arc 5, diagnostic of hydatid infection. The lower nonspecificity of the LA test, its greater simplicity and its excellent correlation with the immunoelectrophoresis test suggest that it is the choice screening technique for use in field surveys or seroepidemiologic studies of hydatid disease. The advantages and limitations of this serologic approach for the detection of human hydatid cyst carriers in field studies are discussed.

Epidemic glomerulonephritis in Maracaibo. Evidence for progression to chronicity

In 1968 an outbreak of 348 cases of acute poststreptococcal glomerulonephritis (AGN) was observed in Maracaibo, Venezuela. During the year, the epidemic had three peaks of incidence. Districts with better sanitation showed a lower incidence of disease than those with less adequate facilities. Endemic cases occur every year. Lowering of serum complement activity was observed in 96% and hypertension in 90% of the patients. The mortality rate in the acute phase during the epidemic was 1.31%. A history of antecedent infection was found in 39% of the cases. 70% of these infections were in the upper respiratory tract. During 1973-74, 120 of the patients (19 adults and 101 children) were reexamined. All but one had been completely asymptomatic. Sixteen patients (13.3%) had one or more of the following abnormalities (group A): low CCr, microscopic hematuria, proteinuria of 1 g/day or more and hypertension. One hundred and four patients (86.7%) were normal by all clinical and laboratory parameters tested (group B). The incidence of persisting disease, as judged by biochemical findings, was significantly higher (P less than .01) in adults (36.7%) than in children (8.9%). Percutaneous renal biopsies from 7 patients of group A, and 8 patients from group B, were studied by light microscopy and immune histology. All biopsies from group A patients had evidence of advanced glomerular disease by light microscopy and by immune histology. Seven biopsies from group B patients were also abnormal showing mild changes with corresponding immunologic findings. Only in one patient was the biopsy completely normal. Our studies indicate that significant numbers of patients progress towards chronicity after epidemic, poststreptococcal AGN. Such progression is more common in adults than in children.

Biochemistry of development in insects. Stereospecific incorporation of fatty acids into triacylglycerols

1. Previous experiments showed that fatty acids were incorporated into triacylglycerols by homogenates of Ceratitis capitata larvae far more efficiently than by pharate adult homogenates. This metabolic behaviour of both stages of development of the insect has been interpreted throughout the existence of a different acyltransferase activity. To obtain new data on the acyltransferase mechanism, a time-course of the stereospecific incorporation of labelled myristic, palmitic, oleic and linoleic acids into the sn-positions of triacylglycerols has been followed. 2. Studies on the stereospecific incorporation of labelled fatty acids confirmed previous results. Palmitic acid was mainly incorporated into sn-1 and sn-3 positions whereas position 2 exhibited a low incorporation. Myristic acid acylated sn-3 position at a higher rate than it acylated the other sn-positions. Oleic acid was more specifically distributed than palmitic acid and linoleic acid was more efficiently incorporated than the monounsaturated acid. All these data reflect substrate differences in the acyltransferase activity of larval homogenates. Pharate adult homogenates incorporated fatty acids very scarcely and mainly into positions (1 + 3). 3. Kinetics of incorporation of labelled fatty acids into the sn-positions points to a non-random distribution with respect to the major saturated and unsaturated fatty acids in triacylglycerols of larvae of Ceratitis capitata.