Use of myoblasts in assaying the osteoinductivity of bone morphogenetic proteins

A novel, time- and BMP-saving in vitro method for the detection and quantitation of bone morphogenetic protein (BMP) activity was developed based on the measurable effects of BMP on rat skeletal muscle myoblasts (L6). Calcium incorporation, stimulation of alkaline phosphatase activity and production of osteocalcin were used as markers of bone cell metabolism and on-going morphogenesis. The morphological change was confirmed by Chlorantine fast red and von Kossa staining. The response of various BMPs was purity-dependent and consistent with intramuscular implantations of the same materials. Neither TGF-beta1 nor insulin could induce the same actions. The data from this study indicate that at least in part in vivo implantations of BMP extracts can be replaced by in vitro measurement of osteoinductivity. Considerable saving of time, BMP and experimental animals can be achieved using cell culture conditions for the determination of bone-forming activity.     

Influence of acute injection of chloroquine on the biliary secretion of lipids and lysosomal enzyme on rats

Phospholipids and cholesterol combine with a protein fraction (IgA and an acid polypeptide) in bile to form the bile lipoprotein complex. We wished to determine whether lysosomes participated only in IgA secretion or if their secretory role also involved the lipid components of the bile complex. This aspect was studied with a single acute injection of chloroquine, a lysosomotropic drug. The results show that a nonnegligible quantity of IgA travels through the lysosomes. In addition, phospholipid and cholesterol levels undergo a significant (P<0.05) decrease 1 hr after injection before increasing to normal levels. In contrast to the total inhibition of protein secretion (β-glucuronidase, acid phosphatase), a transitory decrease of the secretion of bile lipids takes place that suggest secretory mechanisms involving organelles other than lysosomes.     

Dietary fats and properties of endoplasmic reticulum: II. Dietary lipid induced changes in activities of drug metabolizing enzymes in liver and duodenum of rat

Rats were fed cholesterol, cacao butter, or olive oil diets to determine the effect of dietary lipids on the rate of drug biotransformation in the liver and duodenum. The cholesterol rich diet maintained the hepatic aryl hydrocarbon hydroxylase activity at the same level as did the standard diet. Rats fed olive oil and cacao butter diets showed lower hepatic aryl hydrocarbon hydrorylase activity. The p-nitroanisole 0-demethylase activity was doubled in hepatic microsomes of rats fed the high cholesterol diet when compared to rats fed the standard diet. The hepatic uridine diphosphate glucoronosyltransferase activity showed different patterns depending on the in vitro treatment of the microsomal membranes. If the enzyme activity was assayed from the native, untreated microsomes, an increase in the measurable uridine diphosphate glucuronosyl transferase activity was found in rats having cholesterol rich diet. After the in vitro activation of membrane-bound uridine diphosphate glucuronosyltransferase by trypsin, the increase in measurable activity was 10 fold in the group fed the standard diet, 6 fold in group fed cholesterol, 4 fold in group fed cacao butter, and 3 fold in group fed olive oil. Trypsin digestion of microsomes increased the measurable uridine diphosphate glucuronosyltransferase activity less in rats fed diets rich in neutral fats than those fed the standard diet. In the duodenal mucosa, lipid diets decreased the activities of drug hydroxylation and glucuronidation.     

Some properties of linear strain triangles and optimal finite element models

A detailed study of the linear strain triangle (LST), which is very applicable in plane stress finite element analysis, is presented. Based on analytical stiffnesses, it is shown that the LST stiffnesses are easily obtainable from the stiffnesses of the corresponding simple constant strain triangle (CST). The optimization of finite element models is related to the configuration of the elements, and this analysis is also based upon the LST element. A procedure for changing to an improved finite element model is presented which does not require re-analysis. Several examples are discussed.     

Evidence for sex transformation of germline cells in ovarian tumor mutants of Drosophila

Mutations at a few genetic loci in Drosophila cause ovarian tumors with hundreds of poorly differentiated germ cells. We examined several of these mutants to test the hypothesis that such ovarian tumors contain sex-transformed cells. By testing for expression of male germline traits, we determined that partial germline sex transformation occurs in otu, snf, Sxlfs, and bam ovarian tumors. Thus these genes are likely to be required for proper establishment of germline sexual identity.     

Quantitative Mineral Assessment of Apatite, Calcite/Dolomite, and Phlogopite Powder Mixtures by Using VSWIR Reflectance

Quantitative assessment of mineral powders made from mono/two-mineral blocks sampled from the Siilinjarvi apatite ore deposit is the target of this paper. The blocks were composed of apatite, calcite/dolomite, and phlogopite. The blocks were powdered and mixed into a set of 21 well-documented mixtures. Their visible to short-wave infrared (VSWIR) reflectance spectra were recorded by using the FieldSpecFR Spectrometer. Linear unconstrained unmixing of the spectra resulted in highly biased estimates in spite of the fact that the mean absolute residual error of the unmixing was very small. The bias, which is actually induced by camouflage between mineral classes, could approximately be removed by a polynomial function. This resulted in unbiased estimates for apatite calcite/dolomite and phlogopite. Best results were obtained when the wavelengths were limited to the SWIR area only. This two-part procedure consisting of the linear unmixing and the camouflage correction gives one more aspect to subpixel classification. Training data are given not only for the classes but also for their interaction. In this paper, the mean absolute residual error of the estimated volumetric fractions of apatite, calcite/dolomite, and phlogopite from the spectra was 1.32%, which is smaller than the result in the previous VSWIR studies concerning the assessment of mineral powders. This reflectance method offers a very quick tool for several mineral-related applications.     

Transformation of Lowland Rainforest into Oil-palm Plantations and use of Fire alter Topsoil and Litter Silicon Pools and Fluxes

Silicon - The effects of land use and fire on ecosystem silicon (Si) cycling has been largely disregarded so far. We investigated the impacts of land use and fire on Si release from topsoils and...