Loss of Niemann-Pick C1 or C2 Protein Results in Similar Biochemical Changes Suggesting That These Proteins Function in a Common Lysosomal Pathway

Niemann-Pick Type C (NPC) disease is a lysosomal storage disorder characterized by accumulation of unesterified cholesterol and other lipids in the endolysosomal system. NPC disease results from a defect in either of two distinct cholesterol-binding proteins: a transmembrane protein, NPC1, and a small soluble protein, NPC2. NPC1 and NPC2 are thought to function closely in the export of lysosomal cholesterol with both proteins binding cholesterol in vitro but they may have unrelated lysosomal roles. To investigate this possibility, we compared biochemical consequences of the loss of either protein. Analyses of lysosome-enriched subcellular fractions from brain and liver revealed similar decreases in buoyant densities of lysosomes from NPC1 or NPC2 deficient mice compared to controls. The subcellular distribution of both proteins was similar and paralleled a lysosomal marker. In liver, absence of either NPC1 or NPC2 resulted in similar alterations in the carbohydrate processing of the lysosomal protease, tripeptidyl peptidase I. These results highlight biochemical alterations in the lysosomal system of the NPC-mutant mice that appear secondary to lipid storage. In addition, the similarity in biochemical phenotypes resulting from either NPC1 or NPC2 deficiency supports models in which the function of these two proteins within lysosomes are linked closely

Does the gender of the subject affect perceived smile aesthetics when varying the dimensions of maxillary lateral incisors?

Objective To assess whether subject gender influences aesthetic opinion when altering the width of maxillary lateral incisors. Method Photographs of a male and a female smile, displaying only the lips and teeth, were digitally altered to produce images where the maxillary lateral incisor was proportioned 52%, 57%, 62%, 67%, 72% and 77% in relation to the width of the maxillary central incisor. The image was then made symmetrical. One hundred participants (50 male and 50 female) were asked to rank each set of photographs from 'most' to 'least attractive'. Result The 57% lateral incisor was considered the 'most attractive' with the 77% lateral incisor the 'least attractive' however no statistically significant difference existed with relation to subject or rater gender. Conclusion Neither the 'golden proportion' nor the 'Recurrent Aesthetic Dental' ('RED') proportion was deemed the most attractive. As subject gender did not have a significant effect, dentists should work to create aesthetic results on an individual basis, operating within a so-called 'golden range'

Problems of thiamine deficiency states and their amelioration

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Effect of cysteine on respiration and catalase synthesis by Saccharomyces cerevisiae

Catalase synthesis can be induced in anaerobically grown cells of Saccharomyces cerevisiae by aeration (Chantrenne, 1954). In a study of the effect of various nitrogenous substances on the ability of anaerobically grown yeast cells to synthesize catalase, it was found that cysteine inhibited the catalase induction severely (Bhuvaneswaran, Rege & Sreenivasan, 1961). In the present paper, the effect of cysteine on catalase synthesis and on respiration is examined in more detail

Lysosome lipid storage disorder in NCTR-BALB/c mice. I. Description of the disease and genetics.

We describe a strain of BALB/c mice, designated NCTR-BALB/c, carrying a new genetic disorder characterized by excessive tissue deposition of cholesterol and phospholipid. The mice exhibit progressive incoordination, grow less rapidly, and die 80-120 days after birth. In comparison with control animals of the same age, organ weights in the affected animals are lower in absolute value but higher relative to body weight, except for the thymus, which is atrophied, and for the lung and testes, whose absolute weights are not changed. Vacuolated cells are found in many tissues, and large foam cells are present in reticuloendothelial system (RES)-rich organs. Compared with those of BALB/c controls, serum lipoproteins migrate more slowly on electrophoresis; the amount of beta-lipoproteins is increased, while alpha-lipoprotein content is decreased. Serum total cholesterol remains normal. The serum activities of aspartate aminotransferase, creatine phosphokinase, and N-acetyl-beta-glucosaminidase are elevated. Free cholesterol levels are increased 8-10-fold in liver, spleen, and thymus, and about 2-fold in other tissues; but esterified cholesterol levels are normal. The phospholipid content of several tissues is increased 50-100%, largely as a result of an increase in sphingomyelin content. Significant increases in phosphatidylcholine occur also in spleen and lung. The disorder is inherited, affecting both sexes equally, and appears to be transmitted as an autosomal recessive mutation