Renal toxicity. Tobramycin and gentamicin

To see if urinary 2-methyl-4-chlorophenoxyacetic acid (MCPA) excretion could be used to estimate MCPA exposure, four healthy males ingested 5 mg MCPA. The MCPA in the urine was extracted and anlyzed by high pressure liquid chromatography. About 50% of the ingested dose was detected in the urine within 48 h. On the fifth day after intake the MCPA concentration in the urine was below the level of detection, 0.2 microgram/ml. The MCPA did not increase those serum enzymes indicating liver cell damage (S-alanine-aminotransferase, S-alkaline-phosphate). Some creatine kinase (CK) and S-aspartate-aminotransferase (ASAT) values were pathological, but, as all CK values were normal in two persons and all ASAT values were normal in three persons, it not likely that MCPA had a toxic effect on muscle cells. MCPA in urine seems to be a useful indicator of MCPA intake in humans. All the urine passed within 48 h of MCPA exposure must be collected.     

A multiaperture collimator for use at 511 keV

The addition of autologous serum to mixtures containing human red cells, from pregnant and nonpregnant females, and sheep cells resulted in the formation of mixed aggregates containing both human and sheep red cells. In contrast, no aggregate formation occurred when autologous cord serum was added to mixtures containing cord red cells and sheep red cells. Heat inactivation of the adult serum or the presence of 0.15 M EDTA prevented the formation of mixed aggregates. These observations indicated that the mixed aggregates occurred through the complement-dependent red cell immune adherence (RCIA) phenomenon. The addition of untreated cord serum to mixtures containing inactivated adult serum restored the formation of mixed aggregates, indicating that the cord serum contained sufficient complement for RCIA. Natural antibody against sheep red cells was present in adult sera but was absent in cord sera. Using the RCIA receptor assay, the RCIA receptor activity of cord red cells was found to exceed significantly that of the adult pregnant cells (p less than 0.0025). It is postulated that this may represent an aspect of immune adaptation between mother and fetus.     

Automatic collector of expired 14CO2 for liquid scintillation counting

A filtration technique was employed to trap 14CO2 continuously for liquid scintillation counting. Devices for delivering scintillator and ethanolamine solutions were combined symmetrically with two fritted-glass aspirators for alternating operation. The collector was regulated by a fraction collector timer. Trial and animal tests indicated that the described method was efficient, reliable, and more convenient for frequent collection over long periods than alternative methods. The automatic collector was used for metabolic studies of [1-14C] arachidonic acid in rats kept in metabolic cages and the results were processed by multicompartmental analysis.     

Hyperthyroidism induced by iodine in an apparently normal thyroid gland. A new iatrogenic disease

Iodine-induced thyrotoxicosis was reported to occur in patients with previously altered thyroid gland. Evidence is presented here from 23 cases that iodine-induced thyrotoxicosis may also occur in patients with no prior thyroid desorder and is characterized by: a) an almost undetectable 131I uptake, wich can be activated by TSH; b) a spontaneous improvement within a few weeks or months after withdrawing the high intake of iodine; c) the absence of any detectable thyroid abnormality after recovery.     

Chiasmal syndrome due to intrasellar abscess

A 43-year-old woman had diabetes insipidus and amenorrhea. There was panhypopituitarism on endocrine testing and visual field examination showed inexorably progressive loss to bitemporal hemianopsia. All radiographic findings were normal, but craniotomy disclosed the cause of this chiasmal syndrome to be an intrasellar abscess which, on culture, grew a Gram-positive anaerobe, Peptococcus. Intrasellar or pituitary abscess is rare, but it must always be considered in the differential diagnosis of the chiasmal syndrome, since loss of pituitary and visual function may occur much more rapidly than with the tumors most often responsible for this syndrome and since surgical cure is possible.     

Etiology of growth failure in a clinic population

To identify the basis of growth failure, the background of preschool children whose growth fell below 97 per cent of their peers was compared with that of those who demonstrated a higher level of growth achievement. A questionnaire administered at the home of each child documented living conditions, health history, and other family characteristics. Families of the growth-retarded children had higher income, higher credit payments, and used higher dollar values of Food Stamps. A greater percentage of the growth-retarded children were low-birth-weight infants. However, neither low birth weight nor any other one factor consistently predicted poor growth achievement. The need for adequate growth standards to correctly diagnose achievement remains a primary need in the field of nutritional assessment.     

Instability of rat liver chromatin and other nuclear non-histone proteins in alkaline solution

Non-histone proteins from rat liver nuclei and chromatin were shown to be hydrolysed in 0.1M or-1M-NaOH solutions both at 4 degrees and 18 degrees C; 24h in 1M-NaOH at 18 degrees C is sufficient to break down approx. 77% of these proteins to low-molecular-weight peptides. Loss of protein material banding in the region of pH5.5-8.0 has been demonstrated by isoelectric focusing in polyacrylamide gels, and fine high-molecular-weight bands are no longer visible on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The results indicate that care must be taken when analysing non-histone-protein fractions to avoid exposure to alkaline pH conditions.