Notes on the distribution of phytoplankton in some Kenya waters

The distribution of the major plankton algae in a number of Kenya waters is described. The lakes and dams are shown to fall into ecological groups related to figures for the pH, conductivity and alkalinity of their waters and characterised by the dominance of certain types of alga. The composition of the phytoplankton collected at approximately monthly intervals from Sasumua and Ruiru reservoirs is described. Plankton periodicity is demonstrated for both waters and is shown to be related to rainfall. The periodicity of plankton in Lake Naivasha is noted.     

The effects of decreased growth temperature on the cystine content of cystinotic fibroblasts

Cystinotic fibroblasts transferred from 37 degrees C to 28 degrees C accumulated additional cystine over the period from 4 to 7 days of incubation at 28 degrees C, after which the additional cystine was lost; warming (to 37 degrees C) of cells with elevated cystine stores led to rapid cystine loss. These results, taken together with previously published data showing cystine release from cystinotic fibroblasts incubated at above-normal temperature, are interpreted as indicating the presence in the cystinotic fibroblast lysosome membrane of a cystine-porter whose efficacy is increased by an increase in membrane fluidity. This porter may be the residual activity of the cystine porter that is known to be deficient in cystinosis, or it may be a second as yet unrecognized porter. It is further proposed that this porter is responsible for the presumed efflux of cystine from cystinotic lysosomes.     

CATECHOLAMINE METABOLISM IN THE DOG: COMPARISON OF INTRAVENOUSLY AND INTRAVENTRICULARLY ADMINISTERED [14C]DOPAMINE AND [3H]NOREPINEPHRINE

—The urinary excretion of labelled metabolites was measured in dogs which had been injected intravenously or intraventricularly with [³H]norepinephrine or [¹⁴C]dopamine. [³H]Norepinephrine injected by either route produced more labelled 3-methoxy-4-hydroxy-phenylglycol than 3-methoxy-4-hydroxymandelic acid, as did [¹⁴C]dopamine after intravenous administration. In contrast, following the intraventricular injection of [¹⁴C]dopamine, more [¹⁴C]3-methoxy-4-hydroxymandelic acid was formed than [¹⁴C]3-methoxy-4-hydroxyphenylglycol. These observations suggest that the metabolism of exogenously-administered and endogenously-formed norepinephrine may proceed through different routes and that the predominant metabolite of norepinephrine in canine brain may be 3-methoxy-4-hydroxymandelic acid rather than 3-methoxy-4-hydroxyphenylglycol.     

Single-dose Therapy with Streptomycin and Sulfametopyrazine for Bacteriuria during Pregnancy

One hundred and sixty-three patients with bacteriuria in pregnancy were treated with a single dose of antibiotic. Four regimens were used: sulfadoxine (sulphormethoxine) 2 g., sulfametopyrazine 2 g., streptomycin 1 g., and a combination of sulfametopyrazine 2 g. and streptomycin 1 g. The highest cure rate of 77% was achieved with streptomycin and sulfametopyrazine. The long-acting sulphonamides alone gave a cure rate of 55% while streptomycin alone eradicated 43% of the infections. Despite the high cure rate with combined therapy bacterial resistance developed in some cases.     

Sacramento's Day-Treatment Center for Autistic Children

A report of two years'' operation of a day-treatment center for autistic children is given. A brief historical review and a capsule summary regarding current concepts on autism are presented. The educational and treatment programs at the center are described, and two case vignettes illustrate the progress of the children. Highlights from group counseling sessions with the mothers of autistic children reveal the conflicts with which parents of disturbed children must deal. The two-year experience indicates that the identification of autism at an early age is crucial and that a day-treatment facility has much to offer the psychotic child and his parents.     

Diversifications in the Tube Dilution Test for Antibiotic Sensitivity of Microorganisms

The tube dilution method of performing antibiotic sensitivity tests is commonly employed as an accurate method for defining the minimal inhibitory concentration in relation to pathogenic organisms. It is also used as a reference for comparing minimal inhibitory concentrations with the size of the zone of inhibition in the agar diffusion test. Although surveys have shown that there is no standardized method and technique of performing the tube dilution test, it is generally assumed that all of the diversified methods will yield the same results and interpretations. With the assistance of five experts, seven different tube dilution methods were compared; 16 antibiotics, and three organisms for each antibiotic, were used. The conclusions drawn are that, although the accuracy of a single method within its own confines is acknowledged, the minimal inhibitory concentrations and interpretations cannot be interpolated from one laboratory to another where a different technique is employed. The results are frequently discrepant. It is suggested that a uniform method be developed and promulgated for general use.     

Screening of yeast strains capable of hyperproducing amylolytic enzymes

Summary Fifteen strains of yeast, which produced an extracellular amylolytic enzymes, were isolated from nature. One of them produced more than 100 times the enzyme activity in comparison with the 14 strains and the extremely hyperproducing strain of yeast was identified asCandida sp. 347. Paper chromatograms of the amylolytic enzyme demonstrated activity of amyloglucosidase. The optimum pH for activity of the enzyme was 5.5–6.0 and optimum temperature was 60°C.