Showing papers by "Mahidol University published in 1971"

Wolffia arrhiza as a possible source of inexpensive protein.

Abstract: THE development of new foods is vital to the needs of the rapidly expanding population in Asia. But apart from the necessity of being competitive in market price, they must be acceptable to the human palate, a requirement that has often frustrated attempts to introduce new foods. In this light, the improvement of production and processing of a commodity which is currently marketed for direct human consumption but on a small and inefficient scale has several advantages. Such a commodity is the aquatic plant, Wolffia arrhiza Wimm., Lemnaceae, known to have been used as a vegetable by the Burmese, Laotians and the people of northern Thailand for many generations. The local Thai name for the plant, “khai-nam”, may be literally translated as eggs of the water and suggests the oval shape of the plant (length 1.5 mm, width 1.0 mm). Khai-nam is generally regarded as a poor people's food and has attracted little attention as a potentially significant source of human food. The species also occurs in India1, but no report has been made pertaining to its application as a food source in that country.

The light and the electron microscopic studies of Peyer's patches in non germ-free adult mice.

Abstract: Peyer's patches of conventional adult mice are studied with light and electron microscopy. Based on cellular types and distribution, each lymphoid follicle of Peyer's patch is divisible into four zones: the germinal center, the small lymphocytic, the interfollicular and the subepithelial zones. Three distinct cell types are present in the germinal center, i.e., dendritic reticular cells; tingible body macrophages; and lymphocytes which are classifiable into large, medium and small size. The medium size lymphocytes are the great majority in this zone. The small lymphocytic zones are characterized by a predominance of small lymphocytes with a few reticular cells. The subepithelial zone has a remarkable accumulation of macrophages and plasma cells. In the interfollicular zones there are predominantly small lymphocytes with considerable round macrophages and plasma cells, and this zone is permeated with several post-capillary venules. The distinctive characteristics of small capillaries of the patches are also described.

Experimental infection of Aedes aegypti and Aedes albopictus with dengue viruses.

Abstract: The susceptibility of two Aedes (Stegomyia) species, Ae. aegypti and Ae. albopictus, to infection with dengue virus was assessed using both natural feeding on a viraemic gibbon and a membrane feeding technique. Both species were highly susceptible to dengue virus infection. It was found that both species were more sensitive than the LLC-MK2 cell plaque assay system used in detecting viraemia in a gibbon infected with a low tissue culture passage strain of dengue-2 virus. However, the same strain passaged in LLC-MK2 cells failed to infect either species when the mosquitoes were fed upon a suspension of this virus. Both species were infected readily when fed upon a suspension of a mouse adapted strain of dengue-2 virus.

The metabolism of retinyl methyl ether in the rat in vivo.

Abstract: 1. Retinyl methyl ether was converted into vitamin A in vitamin A-deficient rats regardless of whether administered by oral, intraperitoneal, intramuscular or subcutaneous route; intramuscular administration seemed to be the best for conversion as well as storage. 2. Significantly, unchanged retinyl methyl ether was also found in the liver after oral administration but not after administration by other routes. 3. Oral administration of 1mg of retinyl methyl ether led to a progressive increase in liver vitamin A with time reaching a value of 16% of administered dose after 24h. No retinyl methyl ether was detectable in liver at any time-interval in this experiment. 4. Conversely, oral administration of 4mg of retinyl methyl ether/day for 4 days led to the accumulation of 25% of the dose as unchanged retinyl methyl ether in the liver 1 day after the last dose; however, it was gradually but completely converted into vitamin A over a period of 18 days. 5. The significance of these findings with special reference to the fundamental metabolism of vitamin A, the site of conversion of retinyl methyl ether into vitamin A, the relative efficiency of various routes of administration and its biological activity are discussed.

A glutinous rice culture medium for demonstration of chlamydospores of Candida albicans.

Abstract: Thirty-four recent isolates ofCandida albicans from clinical material were cultured on glutinous rice agar at 21 pH values ranging from 2.2 to 11.9. After incubation at 25°C all isolates produced chlamydospores on this medium at pH values from 6.6 to 8.0 with an optimum pH of 7.1. Nineteen stock cultures and all recent isolates ofCandida albicans were used to compare the new glutinous rice agar with 9 other culture media recommended for chlamydospore formation. The results indicated that the new medium was superior in terms of (1) economy, (2) rapid production of chlamydospores, (3) transparency and (4) ease of investigation by direct microscopic examination.

Inotropic actions of lignocaine and phenytoin.

Abstract: 1. The inotropic effects of two antiarrhythmic drugs, lignocaine and phenytoin, were studied in electrically driven isolated rabbit atrial preparations. The time-effect relationship of each drug was investigated with different concentrations and frequencies of stimulation.2. The effects of time of exposure, drug concentration and heart rate on the development of beat alterations (cessation of beat, skipped beat, alternating variation of force of contraction and extrasystole) were also studied.3. When the chronotropic effects of both drugs were prevented, the inotropic effects were positive or negative depending on the concentration of drug, time of exposure and frequency of stimulation.4. At concentrations higher than those obtained in the blood of man on maintenance doses, alteration of the beat occurred but was consistent with the peak blood concentrations immediately after the injection of standard clinical doses. The time of onset of beat alteration shortened when either drug concentration or frequency of stimulation was increased.5. The beat alteration produced by antiarrhythmic drugs can account for various adverse effects associated with their clinical use. These effects include transient ventricular tachycardia and extrasystole during and shortly after injection of drug, ventricular tachycardia, ventricular fibrillation and cardiac arrest due either to excessive dose or to persistent tachyarrhythmia if the dose is not excessive.

Xg Blood Groups of Thais

Abstract: SAMPLES of blood from 181 normal unrelated Thais from Bangkok have been tested for the X-linked blood group antigen Xga. The results are shown in Table 1.