[Statistics for initial admission for schizophrenia in hospitals in Costa Rica]. / Tasas de ingreso inicial por esquizofrenia en hospitales de Costa Rica.

The factors that influence hospital admissions for schizophrenia in Costa Rica were investigated in people of both sexes who were admitted for the first time with this diagnosis (codes 295.0 to 295.9 of the International Classification of Diseases, Ninth Revision) in the period 1979 to 1981. Annual incidence rates were calculated using the number of hospitalized cases and the total population of the country. The average annual incidence was found to be 48.2 cases per 100000 inhabitants. High frequencies of first admissions were seen among males 40 to 44 years of age and females 45 to 49. Incidence was highest among unmarried women, followed by divorced women. There was a significant inverse relationship between educational attainment and rates of admission for schizophrenia, and incidence rates were highest among unemployed women and housewives. The association between rate of hospitalization for schizophrenia and 10 characteristics of the cantons was studied by means of logistic regression. Only two variables-the distance between the canton's principal town and the hospital and the volume of coffee harvest per resident-showed a direct significant association with admission rates for schizophrenia. The cantons which had the highest number of births of children who were diagnosed as schizophrenic in adulthood were those closest to the psychiatric hospital and those that had a low level of industrial or agricultural activity, low population density, and high proportions of single or divorced persons.

Rates of first hospitalizations for affective psychoses in Costa Rica.

What demographic, geographic and temporal factors characterize the rate of first hospitalizations for affective psychosis in Costa Rica? This report presents graphically the first hospitalization rates for the whole country of Costa Rica, with analysis of specific rates for the subgroups by age, sex, marital status, level of education, occupation, place of residence, and place of birth, as well as separate rates by month and date of hospital admission, monopolar first admissions increased slowly from the age of 10 to the age of 45 years, then "exploded" to a peak between 55 and 65 years, then declined somewhat. The educational group among men with the highest rate was the group with at least some university education. Professionals, clerical workers, unskilled laborers, and those with no occupation had high rates. Higher rates were also associated with being single, divorced, widowed, having no occupation, and living in rural, coffee-growing areas that were not too distant from the hospital.

The effect of phosphate, nitrogen and sucrose on the production of phenolics and solasodine in callus cultures of solanum laciniatum.

In leaf derived callus cultures of Solanum laciniatum Ait. both phenolics and solasodine concentrations increased when medium phosphate or nitrogen concs. were reduced to one-eighth or when sucrose concentration was increased from 3 to 4-8 %. Under these conditions growth was reduced and final FW:DW fell. Growth was inhibited by sucrose depletion and nitrogen supple -mentation. On additional nitrogen the concentrations of phenolics and protein significantly increased, FW:DW was reduced and solasodine concentration was unaffected. In seedling derived cultures phosphate depletion resulted in a significant increase in phenolics concentration, an inhibition of growth and a rise in solasodine concentration.

A study of the subcellular localisation of an ethylene binding site in developing cotyledons of Phaseolus vulgaris L. by high resolution autoradiography.

Use was made of light microscopy and high resolution electron microscope autoradiography to determine the subcellular localisation of a binding site with a high affinity and specificity for ethylene in developing cotyledons of Phaseolus vulgaris L. The results indicate that the binding site is located on the endoplasmic reticulum and protein body membranes, confirming previous studies using cellular fractionation and marker enzymes.

Studies on ethylene binding by cell-free preparations from cotyledons of Phaseolus vulgaris L. : I. Separation and characterisation.

The preparation is described of a cell-free system from developing cotyledons of Phaseolus vulgaris cv. Canadian Wonder which is capable of binding ethylene. The binding is saturable and the apparent dissociation constant for ethylene is 6.4·10(-10) M in solution. The binding site is associated with subcellular particles and treatment with Triton X-100 results in substantial solubilisation of the activity. The kinetics of association and dissociation of the ligand and the binding site are described. The system is heat labile and binding activity is diminished by treatment with some proteolytic enzymes.

Studies on ethylene binding by cell free preparations from cotyledons of Phaseolus vulgaris L. : II. Effects of structural analogues of ethylene and of inhibitors.

Various protein reactive agents such as dithioerythritol, dithiothreitol, mercaptoethanol and p-chloromercuribenzoate inhibit binding of ethylene to cell free preparations of Phaseolus vulgaris L. The effect of the thiols is partially reversed by treatment with diamide; occupation of the binding site by ligand diminishes the inhibition caused by p-chloromercuribenzoate but not that caused by thiols. Growth regulators other than ethylene do not affect binding. Physiologically active structural analogues of ethylene competitively inhibit binding of the growth regulator and their relative effectiveness in the cell free system closely resembles that in developmental processes controlled ethylene.

Rapid differentiation of tracheary elements in cultured explants of Jerusalem artichoke.

the culture of Jerusalem artichoke (Helianthus tuberosus L.) tuber explants on filter paper discs moistened with liquid medium resulted in rapid and consistent xylem differentiation. The number of tracheary elements increased in discrete steps, the first at 48 h with a second at 56-58 h, following partially synchronous mitoses at 20 and 30 h. Factors favouring xylem cell differentiation were optimum levels of both an auxin and a cytokinin, low medium nitrogen concentrations, small volumes of medium, and high culture temperatures. A cell counting method employing Feulgen-stained nuclei and suitable for quantifyings small numbers of immature tracheary elements is described.

DNA and histone content of immature tracheary elements from cultured artichoke explants.

Relative amounts of DNA and histone were determined by Feulgen microdensitometry and alkaline fast-green microdensitometry in differentiating tracheary elements in cultured explants of Jerusalem artichoke (Helianthus tuberosus L.) tubers. The absence of endopolyploidy in cultured artichoke tissue was confirmed, and the nuclei of tracheary elements were exclusively at the 2C level for both DNA and histones.