An assessment of skeletal craniofacial asymmetry in South Indian population.

The present study was undertaken to assess the skeletal craniofacial asymmetry in South Indian population by a posteroanterior cephalometric radiographic method. The skeletal craniofacial structures on one side of the face were compared with that of the other, by drawing various triangles representing different craniofacial regions. The sample consisted of 60 subjects (30 males and 30 females) aged between 18 to 25 years, who were mainly dental college students from South India. Overall 52 X-rays were obtained, with four errors each in the male and the female groups. The results revealed that the total facial structures in the South Indian population were larger on the left side (statistically insignificant). The cranial base area exhibited a greater degree of asymmetry than any other component area of the face, which might be due to the inaccuracy at the condylar point.

Cercarial dermatitis in central India: an emerging health problem among tribal communities.

Although cercarial dermatitis is an emerging disease world-wide, cases of such dermatitis may often go undiagnosed, especially in communities that are affected by various skin infections. Between August 2001 and July 2002, 1336 individuals from tribal villages in central India were examined for dermatitis. Skin scrapings were collected and examined for Sarcoptes scabiei and each subject's response to antiscabies treatment was recorded. Freshwater snails were collected from the local ponds used for bathing, and examined for cercariae. The recorded prevalence of dermatitis ranged between 2.1% and 12.5% during the study year, peaking at the end of winter (February-March) and during the rainy season (August-October). Snail positivity for cercariae peaked in the rainy season. The prevalence and the severity of dermatitis were both higher in children than in adults. As most recorded cases of dermatitis were associated with a rash that developed soon after bathing in the local pond, all the skin scrapings were negative for itch mites, and the response to antiscabies treatment was poor, most if not all of the dermatitis observed was probably cercarial. Cercarial dermatitis therefore appears to be a significant health problem among the tribal populations of central India.

Transgenic manipulation of the metabolism of polyamines in poplar cells.

The metabolism of polyamines (putrescine, spermidine, and spermine) has become the target of genetic manipulation because of their significance in plant development and possibly stress tolerance. We studied the polyamine metabolism in non-transgenic (NT) and transgenic cells of poplar (Populus nigra x maximowiczii) expressing a mouse Orn decarboxylase (odc) cDNA. The transgenic cells showed elevated levels of mouse ODC enzyme activity, severalfold higher amounts of putrescine, a small increase in spermidine, and a small reduction in spermine as compared with NT cells. The conversion of labeled ornithine (Orn) into putrescine was significantly higher in the transgenic than the NT cells. Whereas exogenously supplied Orn caused an increase in cellular putrescine in both cell lines, arginine at high concentrations was inhibitory to putrescine accumulation. The addition of urea and glutamine had no effect on polyamines in either of the cell lines. Inhibition of glutamine synthetase by methionine sulfoximine led to a substantial reduction in putrescine and spermidine in both cell lines. The results show that: (a) Transgenic expression of a heterologous odc gene can be used to modulate putrescine metabolism in plant cells, (b) accumulation of putrescine in high amounts does not affect the native arginine decarboxylase activity, (c) Orn biosynthesis occurs primarily from glutamine/glutamate and not from catabolic breakdown of arginine, (d) Orn biosynthesis may become a limiting factor for putrescine production in the odc transgenic cells, and (e) assimilation of nitrogen into glutamine keeps pace with an increased demand for its use for putrescine production.

Polyamines in embryogenic cultures of Norway spruce (Picea abies) and red spruce (Picea rubens).

Embryogenic cultures of red spruce (Picea rubens Sarg.) and Norway spruce (Picea abies (L.) Karst.) were initiated from dissected mature zygotic embryos. The tissues were grown on either proliferation medium or maturation medium. On proliferation medium, the embryogenic tissue continued to produce early stage somatic embryos (organized meristems attached to elongated, suspensor-like cells), whereas on maturation medium fully mature embryos developed from the embryonic tissue. Analysis of polyamines in tissues grown on these two media showed that: (1) both putrescine and spermidine concentrations were always higher in cultures grown on proliferation medium than in cultures grown on maturation medium; (2) in both species, spermidine concentrations declined with time in the tissues grown on maturation medium; and (3) spermine was present in only minute quantities and showed only a small change with time. The presence of difluoromethylornithine in the culture medium had little effect on polyamine concentration, whereas the presence of difluoromethylarginine caused a decrease in putrescine concentrations in both red spruce and Norway spruce tissues grown on proliferation medium or maturation medium.

Regulation of DNA synthesis and cell division by polyamines in Catharanthus roseus suspension cultures.

Various inhibitors of polyamine biosynthesis were used to study the role of polyamines in DNA synthesis and cell division in suspension cultures of Catharanthus roseus (L.) G. Don. Arginine decarboxylase (ADC; EC 4.1.1.19) was the major enzyme responsible for putrescine production. DL α-difluoromethylarginine inhibited ADC activity, cellular putrescine content, DNA synthesis, and cell division. The effect was reversible by exogenous putrescine. Ornithine decarboxylase (ODC; EC 4.1.1.17) activity was always less than 10% of the ADC activity. Addition of DL α-difluoromethylornithine had no effect on ODC activity, cellular polyamine levels, DNA synthesis, and cell division within the first 24 h but by 48 to 72 h it did inhibit these activities. Methylglyoxal bis(guanyl-hydrazone) inhibited S-adenosylmethionine decarboxylase (EC 4.1.1.50) activity without affecting DNA synthesis and cell division.

Glucose-6-phosphate phosphohydrolase activity in guinea pig liver microsomes is influenced by phosphatidylcholine. Interaction with cholesterol-enriched membranes.

Guinea pig liver microsomal membranes were cholesterol-enriched by feeding guinea pigs a high-cholesterol diet. Cholesterol enrichment as well as partial lipid removal of normal native microsomes by acetone-butanol extraction resulted in 40-50% loss in activity of the glucose-6-phosphate phosphohydrolase (G-6-Pase) (EC 3.1.3.9) enzyme system. The activity was restored by supplementation of microsomal total phospholipid (PL) and its phosphatidylcholine (PC) species but not with microsomal neutral lipids, cholesterol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, sphingomyelin or diphosphatidylglycerol (cardiolipin). The activity was decreased by sodium deoxycholate but enhanced by dimethylsulfoxide. Egg-yolk PC and asolectin influenced the activity of the enzyme to the same extent as microsomal PC did. Lipid depletion and cholesterol produced an increase in Km while the Vmax was lowered. The non-linearity in the Arrhenius plot of the native microsomes was lost on lipid removal and cholesterol enrichment. The energy of activation (Ea) calculated from the continuous line was found to be lowered to the level that was observed above the break points in intact microsomes. Addition of microsomal PC to the assay system decreased the Km of the enzymatic reaction in native membranes, in partially lipid-depleted and cholesterol-enriched membranes, but did not alter the Vmax values and only marginally influenced the non-linear relationship of the Arrhenius expression of temperature dependence. The ability of immature rat liver phospholipid exchange protein to introduce alien PL into microsomal membrane was used to study the lipid dependence of G-6-Pase. Protein-catalyzed and detergent (cholate)-mediated membrane PL exchange for egg-yolk PC from the PC/cholesterol unilamellar liposomes resulted in substantial loss of enzyme activity. The discrepancies in the influence of PC on G-6-Pase were interpreted by assuming that the enzyme was a two-component system, a surface-located substrate transporter unit and a membrane integral catalytic phosphohydrolase unit. The lipid microenvironment and PL requirement in particular, could be different for the two components, although they represented a single functional unit at the time of enzymatic reaction.

Gossypol inhibition of Ca++ uptake and Ca++-ATPase in human ejaculated spermatozoal plasma membrane vesicles.

Gossypol, a plant-derived polyphenolic compound known to exert contraceptive actions in men, inhibits Ca++-transport and Ca++-activated ATPase in isolated plasma membranes of ejaculated human sperm cells. It also inhibits the membrane bound Mg++- and Na+ + K+-dependent ATPases, 5'-nucleotidase and alkaline phosphatase systems. Ca++-ATPase inhibition by gossypol is non-competitive. It abolishes the discontinuity in Arrhenius expression of temperature dependence of Ca++-ATPase and increases the energy of activation. Phosphatidyl choline and Na+-deoxycholate inhibit Ca++-transport activity in the membrane vesicles. The apparent similarity of Ca++-transport inhibition by gossypol and phosphatidyl choline may indicate the possible capability of this compound to induce changes in the lipid microenvironment of the membranes, wherein the integral proteins operate. Inhibitory effect of gossypol on the plasma membrane Ca++-pump suggests that gossypol may affect sperm motility by a mechanism which is related to the structure and functions of the plasma membrane.

Isolation and chemical composition of surface-active material from human lung lavage.

Surface-active material (SF) was isolated from human lung lavage fluid collected at autopsy employing differential and sucrose density gradient centrifugation. The isolated material showed well-defined electron microscopic structure, consisting of clearly preserved, closely packed vesicles with limiting membranes and inclusion bodies. It showed a very high degree of alkaline phosphatase specific activity and was devoid of other subcellular contaminants. The isolated material also showed a high phospholipid/protein ratio and increasing surface activity when monitored at different stages of purification. It contained 68.5% phosphatidylcholine, 11.5% phosphatidylglycerol and relatively smaller amounts of phosphatidylethanolamine and other individual phospholipid (PL) classes. In addition, cholesterol, unesterified fatty acids, triacylglycerols and other neutral lipids were found. Saturated fatty acids, particularly palmitic acid (16:0), predominated in the major PL fractions. However, various fatty acids of which oleic acid (18:1) constituted a large proportion also are present. Chemical analysis of the material showed that besides lipids and proteins, nucleic acids, sialic acid, hexose, amino sugars, nitrogen and phosphorus were present. The delipidated material showed the presence of three to four proteins as characterized by sodium dodecylsulfate (SDS)-polyacrylamide gel electrophoresis, and gel permeation chromatography on Sephadex G-200 resolved two well-separated peaks. The first fraction contained serum-associated 68 kDa protein, while the second fraction had two apoproteins with molecular weights of 34 kDa and 10 kDa. These two proteins were associated with the SF and they, as well as the whole surface-active material, strongly reacted with the antibody directed against the whole SF in a double-diffusion immunoprecipitation assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of cholesterol and temperature perturbations on membrane hydrolases and transport of calcium and glucose in guinea pig brush border membrane vesicles.

The function of membrane cholesterol (chol) in the regulation of membrane-bound hydrolases and transport proteins has been investigated in chol-enriched membranes of guinea pig intestinal brush borders. Chol-enrichment is accomplished by non-invasive means i.e., dietary manipulation by high-chol diet feeding. Activities of sucrase, lactase and maltase enzyme systems, Na+-dependent and -independent glucose transport and calcium uptake are found to be greatly inhibited by chol both at 22 degrees C and 37 degrees C. Glucose and calcium uptake in native membranes are found to be temperature sensitive processes and produce nonlinear Arrhenius plots with a transition temperature around 22 degrees C. The discontinuity in the Arrhenius expression is lost in chol enriched membranes which is interpreted as the increase in microviscosity imparted by chol in the bulk lipid phase environment where these proteins operate.

Phospholipid dependence of rat brain microsomal glucose-6-phosphate phosphohydrolase.

Partial lipid removal of rat brain microsomes by acetone-butanol extraction resulted in 32% loss of activity of glucose-6-phosphate phosphohydrolase (G-6-Pase) and an increase in Km and energy of activation (Ea) of the enzyme while the Vmax was lowered. The activity was restored by supplementation of microsomal total phospholipid (PL) and phosphatidylcholine (PC) in sonicated dispersions but not with neutral lipids, phosphatidyl ethanolamine, sphingomyelin, phosphatidylglycerol and cholesterol. In both intact and delipidated membranes, the activity was decreased by sodium deoxycholate and enhanced by dimethylsulfoxide. Egg yolk PC and asolectin influenced the activity to the extent of that produced by microsomal PC. PC increased the Km of the enzymatic reaction in intact microsomes but decreased the same in disrupted membrane while the Vmax was not affected in both the membranes. Addition of PC into the assay system lowered Ea of the reaction in both the membrane systems. However, there was no break observed in the Arrhenius plot. Ability of liver nonspecific lipid transfer proteins to introduce alien PL into brain microsomes was used to study lipid dependence of G-6-Pase and investigation of membrane-enzyme interrelationship. Protein catalyzed transfer of egg PC from a donor PC-cholesterol unilamellar liposomes resulted in substantial increase in microsomal membrane PC and total PL and a net reduction in the enzyme activity was observed in intact and delipidated membranes.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of concentration of D,L-2-difluoromethylornithine on murine mammary carcinogenesis.

The appearance of chemically induced mammary gland carcinomas in virgin female Sprague-Dawley rats was blocked by the administration of D,L-2-difluoromethylornithine (DFMO) in drinking water during the stage of tumor promotion. Rats were given injections s.c. at 50 days of age with either 35 mg of 1-methyl-1-nitrosourea (MNU) per kg of body weight or the 0.9% NaCl solution in which the carcinogen was dissolved. At 57 days of age, the rats were each randomly allocated to one of 14 treatment groups. Ten groups (five solvent treated and five MNU treated) were assigned to treatments consisting of 0.00, 0.0625, 0.125, 0.25, or 0.50% (w/v) solution of DFMO in their drinking water; two MNU-treated groups were placed on or removed from DFMO treatment (0.5%; w/v) at 90 days post-carcinogen exposure; and two carcinogen-treated groups received either putrescine (0.5-g/kg diet) or putrescine and DFMO (0.5%; w/v) throughout the experiment. The study was terminated 183 days after carcinogen treatment. All doses of DFMO exerted a protective effect against the induction of mammary cancer; however, only the feeding of the 0.125% and the 0.5% solutions of DFMO resulted in a significant reduction in cancer incidence. The average number of cancers per rat was reduced, and cancer-free time was extended at all concentrations of DFMO. The protective effect of DFMO was sustained following withdrawal of treatment at 90 days post-MNU injection. Feeding putrescine in conjunction with DFMO treatment partially blocked the inhibitory activity of DFMO. DFMO treatment did not affect food or water intake; body weight gain; the weight of ovaries, uterus, adrenal glands, liver, kidney, or spleen; or the periodicity of the estrous cycle. These data provide evidence of an inhibitory effect of DFMO against mammary cancer induced by MNU which cannot be attributed to a systemic toxic effect of this compound.

Effect of D,L-alpha-difluoromethylornithine on murine mammary carcinogenesis.

The development of chemically-induced mammary gland carcinomas in rats was dramatically suppressed by provision of a 1% solution of D,L-alpha-difluoromethylornithine (DFMO) in drinking water. Treatment with DFMO significantly reduced cancer incidence and the average size and number of cancers per rat and prolonged the cancer-free time. DFMO appears to be effective in blocking some aspect of the promotion stage of chemically induced mammary carcinogenesis in the rat.

Isolation of rat mammary epithelial cells for polyamine analysis.

Mammary epithelial cells were isolated from either abdominal-inguinal glands or mammary tumours of rats, after enzymic digestion of the tissues, and were analysed for polyamine content. Optimum conditions were developed for the isolation of cells in sufficient yield for the analysis of polyamines from 1 g of mammary gland or 0.5 g of tumour tissue. Complete recoveries of the polyamines in the tissues were achieved in the isolated epithelial cells.