On the spatial distribution, feeding and reproduction of the vermetid gastropod Dendropoma maximum

D. maximum is a dominant species of outer reef flats in the Red Sea, reaching densities of about 22/m² and biomass of 15.8 g dry tissue/m². A few individuals attached to loose rocks are found inside the breaker zone but they may have been dislodged by heavy seas from the outer reef flat. D. maximum feeds from a mucus net which is spread by wave action over the substratum. Hauling the net occurs at approximately 13 minute intervals throughout the 24 hours and lasts about two minutes. Neighbours with overlapping nets stimulate each other to haul and reduce feeding efficiency. The net is grasped by a pair of lateral jaws, tugged free of the substratum by rotation of the body and ingested by a zipper-like action of the lateral and marginal radula teeth. The robust, central and lateral teeth become worn, possibly while channelling out the substratum to accommodate new shell. Defaecation occurs about 2.4 times an hour, amounting to 10450 kcal/m²/y. Females may brood simultaneously at least 11 egg capsules at various stages of development, which are suspended by stalks from the roof of the shell and pass through a dorsal slit in the mantle. Each capsule contains–500 embryos which develop into larvae with simple, coiled shells 0.33 mm in diameter. There is no planktonic phase. Adult shells amount to 2.5 kg/m² on the outer reef flat, while dead shells are often occupied by blennies. Although D. maximum is not a specialized filter feeder, the highly developed ciliary mechanisms suggest that filtering may be an auxiliary feeding method.     

Isolation of two pure polysaccharides from the hemicellulose of slash pine (Pinus elliottii)

Two pure, acidic polysaccharides have been isolated from the hemicellulose of slash pine in yields of 1–2% and 4–5%. Their properties are compared, and the structure of one of them has been investigated by methylation analysis. The results indicate that the glycan is a β-D-(1→4)-linked xylan chain with many branch points. 4-O-Methyl-D-glucopyranosyluronic acid, L-arabinofuranose, and D-xylopyranose residues occur as non-reducing end groups. The uronic acid occurs as single-unit attachments to the main chain. Some of the D-xylose residues in the polysaccharide are doubly branched. The total hemicellulose components of the wood probably represent a complex mixture of chemical types, from which the two pure fractions described above may be separated fortuitously by careful, fractional precipitation.     

Studies on the nature of the Li locus in Trifolium repens L. II. The effect of genotype on enzyme activity and properties

Various reagents which prevent enzyme inhibition by phenolic compounds were tested in attempts to improve the medium used to extract the Li-controlled enzyme activities from white clover leaves. The addition of 50 mm diethyldithiocarbamate to the extraction medium gave a fivefold increase in the enzyme activity of LiLi white clover extracts against p-nitrophenyl -d-glucoside, linamarin-lotaustralin, and p-nitrophenyl -d-galactoside. These three substrates were used in tests on the effect of genotype on enzyme activity. An absence of dominance at the Li locus was demonstrated, with a dosage effect of Li alleles on enzyme activity. A new Li allele was identified in the Lili clone, C11, which had low levels of enzyme activity. In crosses with two lili clones, Li(C11)li progeny were produced with activity levels similar to those of the C11 parent. Inhibition and heat-inactivation tests suggest that the lili clone, D4, produces an altered form of -glucosidase which may also be present in LiLi plants. The nature of the Li locus is discussed.     

Application of Urine Analysis to Diagnosis and Treatment of Heroin Addiction

Experience with urine analysis for morphine using thin-layer chromatography in 310 cases of real or possible heroin abuse showed that it was valuable not only in detecting improper drug use but also in monitoring treatment. The results of this test can be available routinely in 24, and exceptionally in five hours. A negative result implies that the subject has taken less than 10 mg. of heroin in the past 24 hours.     

Histochemical detection of l-gulonolactone: phenazine methosulfate oxidoreductase activity in several mammals with special reference to synthesis of vitamin C in primates

Summary An improved detection of activity of l-gulonolactone oxidase, which is responsible for the final oxidative step in the synthetic process of l-ascorbate from glucose in animals, was achieved using phenazine methosulfate and cyanide. Cold acetone fixation eliminated non-specific deposition of formazan on lipid droplets. The specificity of the method was tested and proven by a biological control, histochemical controls, inhibitors and activators. By application of the method, strong reactivity was found in the cytoplasm of centrilobular parenchymal cells of livers of the opossum, rat, ground squirrel and flying squirrel. Staining of dog liver was moderate and centrilobular. Prosimians were strongly positive: The centrilobular localization was found in the tree shrew and galago; slow lorises and some pottos showed strong reactivity in centrilobular cells and some peripheral cells as well. These prosimians seem to be able to synthesize l-ascorbate as many lower mammals are. On the contrary, true simians (i.e. the squirrel monkey, spider monkey, rhesus monkey and chimpanzee) were negative as guinea pigs were, suggesting their probable inability for l-ascorbate synthesis.Visiting scientist from the Department of Anatomy, Tokyo Medical and Dental University, Tokyo, Japan. T. R. Shanthaveerappa in previous publications, also fellow, Department of Anesthesiology, Emory University.     

Histochemical studies on urate oxidase in several mammals with special reference to uricolytic ability of primates

Summary Strong reactivity for urate oxidase was found in the liver parenchymal cells of the prosimians (i.e. the tree shrew, slow loris, potto and galago) as well as those of lower mammals. The liver parenchymal cells of the platyrrhine monkeys (i.e. the marmoset, owl monkey, squirrel monkey, capuchin monkey and spider monkey) were moderately positive. There was no preferential distribution of granular reaction products in zones of liver lobules of these species. The prosimians and platyrrhine monkeys seem to be uricolytic as lower mammals are. On the other hand, the old world monkeys (i.e. Java monkey and rhesus monkey) and the apes (i.e. the orang-utan and chimpanzee) were histochemically negative.     

Fibrosing Alveolitis Associated with Renal Tubular Acidosis

The discovery of a case of renal tubular acidosis and fibrosing alveolitis led to the investigation of 19 further patients. Abnormal pulmonary function tests were found in a further four patients with overt renal tubular acidosis and in four out of eight patients with “incomplete” renal tubular acidosis. The response to an ammonium chloride test in seven patients with cryptogenic fibrosing alveolitis was normal. Those patients with a defect of both renal acidification and pulmonary gas transfer had concurrent autoimmune diseases such as Sjögren''s syndrome and primary biliary cirrhosis. It is suggested that the renal and pulmonary abnormalities may be part of a systemic disorder capable of affecting many organs. Moreover, hyperglobulinaemia and autoantibodies in these patients further suggests that immunological mechanisms are concerned in the pathogenesis of these abnormalities.