Microscopic observations of skin and lymphoid organs in the hairless dog derived from the Mexican hairless

The skin and lymphoid organs of Mexican hairless dogs and their hairless offspring were examined histologically. The hairless dogs lacked most hairs except for sparse hairs on the head, tail and feet. The skin of newborn pups consisted of a thick epidermis with epidermal ingrowths forming the rudiments of hair follicles. In older dogs more than 2 months of age, however, the epidermis was thin and the ingrowths were few. Neither hair follicles nor skin glands were present. The hairy skin of the head and tail had hair follicles with sebaceous glands. Regarding the lymphoid organs, the newborn pups possessed a thymus like haired pups. But in the older dogs more than 2 months of age, the thymus was atrophied and the lymphocyte population was too sparse to demarcate the cortex and the medulla. Lymphocyte accumulation in older dogs was also poor in the spleen and mesenteric lymph nodes. The present findings indicate that the hairlessness of the Mexican hairless dogs and their descendants is accompanied by early atrophy of the thymus after birth, and is followed by poor accumulation of lymphocytes in the thymus-dependent area of the spleen and the mesenteric lymph nodes. The defect of the thymus in the hairless dog seems to be different from that in athymic nude mice and rats. Further studies are needed to elucidate the immunological response and function in hairless dogs.     

Beta-angonists modulate ACh-inhibition of a K current in intestinal smooth muscle cells.

ACh causes a long-lasting inhibition of STOCs via G proteins in intestinal smooth muscle cells. We examined the effects of isoproterenol (Iso) on the ACh-induced inhibition of STOCs in isolated ileal smooth muscle cells using the G omega-seal whole cell clamp technique. In control, ACh (1 microM) completely suppressed STOCs, which did not desensitize over a period lasting 20 minutes. When Iso (10 microM) was added to the bath in the presence of ACh, the ACh-induced inhibition of STOCs was gradually removed. This effect of Iso was prevented by propranolol (10 microM). Application of Db-cAMP (500 microM) mimicked the Iso effects. Intracellulary applied GTP-gamma S (100 microM) gradually suppressed STOCs in the absence of ACh, which could not be removed by either Iso or Db-cAMP. These results suggest that beta-adrenergic stimulation causes a removal of the muscarinic inhibition of STOCs via a cAMP-dependent process.     

Gene-transfer into bone marrow cells

We have intended to improve gene-transfer technique into hematopoietic stem cells for somatic gene therapy. 1) We have developed a new packaging cell line, ampGPE for retroviral production. LTR-less gag, pol or env genes from Moloney murine leukemia virus were separately inserted into BMGNeo vector. Packaging cell lines containing 20-50 copies of these two kinds of plasmid were obtained. Retrovirus stock for gene-transfer have been produced at a high titer (10(5)-10(6) cfu/ml) and without replication-competent viruses by using ampGPE. 2) Retrovirus-transduced murine CFU-GM have been found to selectively proliferate (5-10 fold/week) in liquid capture with recombinant murine IL-3, human IL-6 and G418 to consequently obtain enough amount of, highly concentrated (70-100%), and gene-transferred murine CFU-GM for gene-delivery system.     

Multivariable analysis of serum 3,5,3'-L-triiodothyronine concentration in patients of diabetes mellitus by blood glucose level and body weight

Serum thyroid hormone concentrations, 1-thyroxine (T4), free T4 and 3,5,3'-l-triiodothyronine (T3) were measured in 213 patients of diabetes and analyzed their correlation with metabolic parameters, hyperglycemia and body weight. Haemoglobin A1 (HbA1) was used as an index of hyperglycemia. Body weight was expressed by relative body weight (body weight/standard weight). Among the thyroid hormones, only T3 had significant correlation with HbA1 and body weight (r = -0.476, P less than 0.01 and r = 0.369, P less than 0.01, respectively). Multivariable analysis of serum T3 by HbA1 and relative body weight gave the following regression equation. Serum T3 (ng/dl) = 108 + 0.362 x relative body weight (%) - 3.88 x HbA 1 (%). Though relative body weight had inverse correlation with HbA1, the contribution of the two metabolic parameters to the serum T3 was independent from each other. Our results confirm the previous reports that low T3 in diabetes correlates with severity of hyperglycemia and we report for the first time that serum T3 of diabetic patients has positive correlation with body weight, probably due to still available carbohydrate in spite of disturbances in the metabolism.     

Effect of malting and roasting on reduction of aflatoxin in contaminated soybeans

The effect of malting and roasting on the reduction of aflatoxin in contaminated soybeans was studied. Through the observation of the malting process of contaminated and noncontaminated beans it was found that aflatoxin brought about 50% reduction on germination percentage and radicle length of malts. Malting appeared to have a minimal effect in lowering the aflatoxin content of the soybean and aflatoxin G-1 was more affected than B-1 by the treatment. The contaminated samples of nonmalted, steeped and malted soybeans were roasted at 150 ° C and 180 ° C. Roasting at 180 ° C reduced the levels of aflatoxin by 40 to 73 percent depending on the sample nature. Roasting of both steeped and malted beans was much less effective in the reduction of the toxin levels than that of nonmalted beans and in all cases aflatoxin B-1 was more heat resistant than aflatoxin G-1.Present address: North Dakota State University, Cereal Chem. & Techn., Fargo, ND 58105, USA     

Degradation of Xyloglucan by Wall-bound Enzymes from Soybean Tissue I. Occurrence of Xyloglucan-degrading Enzymes in Soybean Cell Wall

An enzyme preparation that catalyzes the degradation of xyloglucanwas obtained by extraction of the cell walls of soybean hypocotylswith a buffer containing 1.0 M NaCl. The enzyme preparationwas shown to catalyze two-step degradation of xyloglucan. Thepolysaccharide was first degraded into comparatively large fragments,which were then further degraded into monosaccharides. In orderto elucidate the mode of degradation of the xyloglucan duringcell growth, the activities of xyloglucandegrading enzymes ofsoybean-hypocotyl segments were assayed at different stagesof elongation. The total activities of the degrading enzymeswere lower in the elongating regions than in the non-elongatingregions. However, high levels of endo-ß-l,4-glucanasewere found in the elongating regions. These results suggestthat xyloglucan is hydrolyzed by endo-ß-1,4-glucanaseinto comparatively large fragments at the initial stage of growthand the resulting fragments are further degraded into monosaccharidesduring cell elongation. (Received May 20, 1981; Accepted August 8, 1981)     

Chemical composition of Streptococcus mutans cell walls and their susceptibility to Flavobacterium L-11 enzyme

The susceptibility to a cell wall lytic L-11 enzyme from Flavobacterium sp. and the quantitative and/or qualitative composition of the cell walls of some strains of cariogenic Streptococcus mutans and a non-cariogenic strain of Streptococcus mitis were determined. The purified cell walls of S. mutans strains HS-1 (serotype a), BHT (b), NCTC10449 (c), C67-1 (c), C67-25 (c), OMZ 176 (d), MT703 (e), MT557 (f), OMZ65 (g), and AHT (g), and S. mitis CHT contained glutamic acid, alanine, and lysine as well as muramic acid and glucosamine as a peptidoglycan component. Besides these amino acids, significant amounts of threonine were detected in strains HS-1, OMZ65, and AHT cell walls, and considerable amounts of aspartic acid and/or threonine as well as several other amino acids in OMZ176, OMZ65, and CHT cell walls. Rhamnose was a common special component of the cell walls of S. mutans strains BHT, NCTC10449, MT703, B2 (e), MT557, and AHT, and S. mitis CHT. An additional sugar component, glucose, was detected in the cell walls of all of these strains except BHT, and galactose was found in BHT, AHT, and CHT cell walls. Galactosamine was present in S. mitis CHT cell walls. Varying amounts of phosphorus were detected in the cell walls of all the strains examined. The cell walls of all these streptococcal strains except MT703, 6715, and AHT were susceptible to the lytic action of the L-11 enzyme to various extents. No consistent relationship was observed between the amino acid and sugar composition of these cell walls and their susceptibility to the L-11 enzyme. The chemical composition of these cell walls is discussed in terms of the serological classification of S. mutans.     

Presence of a xyloglucan in the cell wall of Phaseolus aureus hypocotyls

The non-cellulosic ß-glucan₁ in the cell wall of Phaseolusaureus hypocotyb was studied. Evidence that xyloglucan is presentin a hemicellulose fraction was obtained by its isolation fromcell wall preparations. This polysaccharide was homogeneouson zone electrophoresis and ultracentrifugation. On acid hydrolysis,it gave glucose, xylose, galactose, and fucose in the approximatemolar ratio of 10 : 7 : 2.5 : 1. Its solution gave a reddishviolet color with iodine-staining solution. The results of partialacid hydrolysis and cellulase treatment suggest a structurein which xylose, galactose, and fucose attached as side chainsto a sequenceof ß-l,4-linked glucose. The xyloglucanisolated accounted for 13.9% of the total non-cellulosic fractions. (Received May 10, 1976; )