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PubMed1985

Chewing ability in patients restored with cross-arch fixed partial dentures.

The chewing ability of subjects with cross-arch fixed partial dentures was compared with that of subjects with complete healthy dentitions and complete-denture wearers. Chewing ability was expressed in terms of the number of chewing strokes, chewing time, chewing efficiency, and chewing performance. Almonds were used as the test food. In terms of chewing efficiency, that is, comminution in relation to time, subjects with cross-arch fixed partial dentures exhibited a chewing ability inferior to that of subjects with complete healthy dentition but superior to that of complete denture wearers. However, in terms of chewing performance, which describes the degree of pulverization before the time of swallow, chewing ability in subjects with cross-arch fixed partial dentures was almost as good as in subjects with complete, healthy dentitions and superior to that of complete denture wearers.

Dental Abutments↗
PubMed1982

The effect of lyophilization on steroid receptor behavior, as defined by sucrose density gradient analysis.

The effects of lyophilization of both cytosol and tissue powder were examined by sucrose density gradient analysis (SDGA) of uterine estrogen receptor (ER) and progesterone receptor (PgR) from pig and calf. Cytosol prepared from lyophilized material (both cytosol and tissue powder) was compared to that prepared concomitantly from frozen, pulverized powders of the same tissue. It was found that both ER and PgR responses to SDG ionic strength and the ability of ER to demonstrate temperature-dependent 4S leads to 5S transformation were unimpaired by lyophilization. In addition, lyophilized cytosol and lyophilized tissue powder gave equivalent results. A few experiments examining lyophilization effects on steroid receptors from human breast biopsies did note some diminution of the 8S form of both ER and PgR following lyophilization, although this effect was variable in extent. It is nevertheless concluded that much lyophilized material exhibits many of the same responses as frozen, and may be used in lieu of the latter, at least within the confines of the parameters described here.

Animals↗
PubMed1983

Extrapancreatic action of sulfonylureas: hypoglycemic effects are not dependent on altered insulin binding or inhibition of transglutaminase.

It has been proposed by others that sulfonylureas exert their extrapancreatic hypoglycemic effects by increasing insulin binding through inhibition of receptor-mediated hormone internalization. In this study, we examined the possibility that the drugs act by inhibiting transglutaminase, an enzyme thought important in the internalization process. For ten days, male rats were fed pulverized chow containing either no drug, glipizide (5 mg/kg initial body wt/d), or tolazamide (75 mg/kg initial body wt/d). Prior to sacrifice, the six-hour fasting level of serum glucose was significantly reduced from 96 mg/100 ml in the control rats to 81 and 42 mg/100 ml in the glipizide- and tolazamide-treated rats, respectively. In contrast, the serum level of insulin was similar for all groups. The activity of transglutaminase in the postnuclear fraction of liver homogenate also was the same for all experimental groups. The specific binding of labeled insulin to purified liver plasma membranes was examined over a broad range of insulin concentrations; once again, there was no difference between experimental groups. Thus, the hypoglycemia caused by sulfonylurea administration could not be attributed to increases in insulin binding, inhibition of transglutaminase activity, or enhanced insulin levels. These data support our previous suggestion, based on in vitro studies, that sulfonylureas act predominately on processes beyond the binding portion of the insulin receptor.

Acyltransferases↗
PubMed1990

Insulin-like growth factors I and II are present in the skeletal tissues of ten vertebrates.

Previous studies have shown that insulin-like growth factor I and insulin-like growth factor II (IGF I and IGF II) constitute an important family of skeletal growth-regulating peptides. We undertook this study to determine if, as in the case of sera in various animals, IGF I and IGF II are conserved in the skeletal tissues of various vertebrates. Skeletal tissues of ten animals representing five of the six vertebrate classes were studied: monkey, dog, sheep, adult mice, neonatal mice, chicken, lizard, frog, trout, and shark. The skeletal tissues were pulverized and demineralized with 10% ethylenediaminetetraacetic acid (pH 7.0) to extract the soluble matrix proteins. The tissue extracts were concentrated, dialized, and subjected to specific human IGF assays. IGF I and IGF II were measured with a radioimmunoassay and a radioreceptor assay, respectively. We found that 1) there are detectable human IGF I- and II-like substances in all extracts, 2) IGF values obtained in the skeletal extracts were not caused by binding protein artifacts, 3) in general there is more IGF II than IGF I, and 4) the skeletal tissue levels of the IGFs are comparable with their respective serum levels. We conclude that, in the skeletal tissues of vertebrates, the IGFs are conserved and may be important regulators of osteogenesis.

Animals↗
PubMed1978

The cytogenetic effect of bleomycin on human peripheral lymphocytes in vitro and in vivo.

The cytogenetic effect of bleomycin (BLM) in human lymphocytes was studied after exposure to different doses during the G0 and G2 phases. BLM produced a marked specific effect on the cell cycle. The main aberration types after exposure in tg0 were dicentrics and deletions; and after exposure in G2, open chromatid breaks. A linear dose--response was calculated for all these aberration types as well as for the number of aberrant cells. In the G2 experiments, partially and totally pulverized cells also increased linearly with dose. The intercellular distributions of the most frequent aberration types after exposure in G0 and G2--the dicentrics and chromatid breaks, respectively--showed over-dispersion. These results show that the cytogenetic effect of BLM may be compared with that of densely ionizing irradiation. Preliminary results of chromosome analysis of three cancer patients in the course of BLM therapy showed effects similar to those in the G0 experiments.

Bleomycin↗
PubMed1982

DNA content of cells with generalized chromosome shattering induced by ultraviolet light plus caffeine.

Asynchronously growing Chinese hamster cells (M3-1) were UV-irradiated (lambda = 254 nm) and then incubated with/without caffeine (2 mM) for 20 h. Microscopic evaluation of metaphase spreads revealed that after UV-irradiation alone (5.0 J/m2) appearing fragmented and/or pulverized ('GCS-like' cells; GCS, Generalized Chromosome Shattering) was very low while it was high following the combined treatment. Cytogenic and flow cytometric analysis of cells obtained by mechanical shaking cultures treated with UV and caffeine indicated that 'GCS-like' cells have the same DNA content as untreated cells in G2 phase and mitosis.

Animals↗
PubMed1987

Different effects of 1-beta-D-arabinofuranosylcytosine and aphidicolin in S-phase cells--chromosome aberrations, cell-cycle delay and cytotoxicity.

Some effects of a 2-h exposure to either aphidicolin (APC) or cytosine arabinoside (ara-C) on S-phase cells of the cell line JU56 have been measured. At a concentration of 1.5 X 10(-5) M of either drug, incorporation of tritiated thymidine into log-phase cultured was reduced by 97-99%. A 2-h exposure to either drug at the same concentration induced chromosome aberrations in cells in S when they subsequently reached mitosis. However, exposure to ara-C induced small numbers of aberrations per damaged cells, and most cells were undamaged. Exposure to APC induced gross chromosomal damage (pulverized chromosomes) in damaged cells. More cells were delayed, and for longer, after exposure to APC than after exposure to ara-C. The results of clonal assays were consistent with the assumption that chromosome aberrations are the proximal cause of reproductive cell death. In the case of ara-C, the results of this and a previous study are consistent with the assumption that cell death and chromosome aberrations are correlated with incorporation of ara-C into DNA in S-phase cells, but that these biological effects manifest themselves only with doses when inhibition of semi-conservative DNA synthesis is greater than 97%.

Animals↗
PubMed1996

Induction of chromosomal aberrations in cultured human fibroblasts by inorganic and organic arsenic compounds and the different roles of glutathione in such induction.

Clastogenic effects of a variety of arsenic compounds were examined on cultured human fibroblasts. The following compounds were tested: inorganic arsenicals (arsenite and arsenate), the major metabolites of inorganic arsenicals in human and experimental animals [methylarsonic acid (MAA), dimethylarsinic acid (DMAA) and trimethylarsine oxide (TMAO)], and water-soluble organoarsenic derivatives [2', 3'-dihydroxypropyl-5-deoxy-5-dimethylarsinoyl-beta-D-riboside (arsenosugar), arsenocholine, arsenobetaine and tetramethylarsonium iodide] found in marine organisms. Arsenic compounds induced mainly chromatid gaps and chromatid breaks. The rank order of compounds in terms of clastogenic potency was arsenite > arsenate > DMAA > MAA > TMAO. DMAA was very potent and caused chromosome pulverizations in most metaphases when present at doses higher than 7 x 10(-3) M. Arsenosugar, arsenocholine, arsenobetaine and tetramethylarsonium iodide were less effective. Depletion of cellular glutathione (GSH) with L-buthionine-SR-sulfoximine (BSO), increased the incidence of chromosomal aberrations induced by arsenite, arsenate and MAA, and markedly suppressed the clastogenic effects of DMAA. DMAA was highly clastogenic even in GSH-depleted cells when the cells were incubated with DMAA in the presence of GSH (5 and 10 mM). These results suggest that GSH might play a role in protecting cells against the clastogenic effects of arsenite, arsenate and MAA. GSH might be involved in the expression of clastogenic actions of DMAA.

Arsenicals↗
PubMed1978

Antimicrobial effects of N2 in vitro.

The antimicrobial effect of the root canal filling material N2 has been studied in vitro. Pulverized as well as intact set N2 inhibited the growth of the mixed bacterial flora of saliva or pure cultures of S. mutants and A. viscosus on blood agar for at least 100 days. Intact set N2 transferred daily to blood agar inoculated with saliva lost its antimicrobial activity after nine transfers. The antimicrobial effect of N2 against S. mutants was found to be bactericidal. N2 also appeared to possess an antimicrobial "vapor effect".

Actinomyces↗
PubMed1985

Effects of alpha-amanitin on the fine structure of adrenal fasciculata cells in the young rat.

The administration of 0.2 micrograms/g/bw of alpha-amanitin to approximately 20 g rats provoked the following nuclear modifications in rat adrenal fasciculata cells at 60 min: chromatin condensation, nucleolar fragmentation, increase in the number of PCG and clumping of ICG in the center of the nucleus. At longer time intervals (2.5 and 4.5 hr) these alterations were more evident, but at 24 hr the nuclear structure was back to normal with the exception of a persistent increased number of PCG. After injection of 0.75 micrograms/g/bw and at 2.5 hr, there was pulverization of condensed chromatin, fragmentation and partial segregation of the nucleolus with increased density of the fibrillar component. Cytoplasmic alterations were severe including cap-shaped mitochondria with electron-dense matrix surrounding lipid droplets, reduced endoplasmic reticulum of vesicular type and clusters of microvesicles with dense content in the Golgi trans-area. At 24 hr, the nuclear and cytoplasmic morphology returned to normal. These findings are interpreted as the morphological counterpart of a disturbance of extranucleolar and nucleolar RNA synthesis, as well as of lipid and lipoprotein metabolism, brought about by the drug.

Adrenal Cortex↗
PubMed1983

Evaluation of amitrole (aminotriazole) for potential carcinogenicity in orally dosed rats, mice, and golden hamsters.

Amitrole was evaluated for carcinogenic potential in lifespan studies on Wistar rats, NMRI mice, and golden hamsters. At the start of the studies the animals were 6 weeks old. Amitrole was administered, mixed with pulverized chow, at dietary concentrations of 0, 1, 10, and 100 micrograms/g (ppm). Each treated group and control group consisted of 75 male and 75 female rats and mice and of 76 male and 76 female golden hamsters. Additional animals were used to evaluate the functional state of the thyroid. Somewhat lower body weights, slightly reduced survival times, and transient effects on thyroid function were observed in golden hamsters at 100 ppm. In mice, a slight increase in pituitary gland hyperemias was seen at 100 ppm; also an effect on thyroid function usually occurred at the same concentration. In rats, a very large number of cystic dilatations of follicles in the thyroid at 100 ppm and a dose-unrelated increase in hemorrhages and hyperemias in the pituitary gland were indicative of an effect of amitrole on these organs. The strongest effect of amitrole on thyroid function, as compared to golden hamsters and mice, was seen in rats at 100 ppm. At this concentration a highly increased number of thyroid and pituitary gland tumors was observed in rats. In golden hamsters and mice, no tumor induction was seen.

Amitrole↗
PubMed1989

Effect of Streptococcus lactis preparation in diet of mice on inhibiting age-dependent loss of superoxide dismutase activity in tissues.

SL-diet was prepared using commercial pellets supplemented with 1% pulverized Streptococcus lactis (SL). SL fed group of ICR strain mice were bred from 8 weeks up to 75 weeks. End-point age for survival in these mice was approximately 75 weeks. No significant differences in survival rate were observed at 75 weeks between the commercial diet and SL-diet group. The superoxide dismutase (SOD) activities in the liver, brain and erythrocytes of 75-week-old mice significantly decreased compared with those aged 10 weeks. Cu.Zn-SOD and Mn-SOD activities in the liver and brain of SL-diet mice were maintained in similar degree in the juvenile group, however, decreased significantly in the commercial diet group. SOD in erythrocytes was slightly decreased and no significant difference was noted in either group.

Aging↗
PubMed1991

Preparation and certification of rice flour-unpolished reference material.

Rice flour-unpolished reference material was prepared from unpolished rice collected from three locations in Japan. This reference material is certified for elemental composition and consists of three samples containing low-level (0.023 microgram/g), medium-level (0.32 microgram/g) and high-level (1.82 micrograms/g) of Cd. The unpolished rice was pulverized, oven-dried, homogenized and finally packaged into 1000 glass bottles. The prepared material satisfied the homogeneity criteria for a reference material. Collaborative analytical studies on the elemental composition of the rice flour-unpolished reference material were conducted using various analytical techniques which lead to the certification. Stable isotope dilution/ICP-MS was successfully applied to the accurate determination of Cu, Zn, Mo and Cd in the reference material. Certified values are provided for Ca, Cd, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Rb and Zn, based on results of determinations by at least three independent analytical techniques. Reference values are reported for Al, As, Br, Cl, Co, Cr, Hg, Se and Sr. The elemental compositions of the three rice flour-unpolished samples are very similar, except for Cd, and are considered typical of Japanese unpolished rice.

Flour↗
PubMed1980

Quillaja bark (soapbark)--induced asthma.

A 24-yr-old man developed sensitization to Quillaja bark (soapbark) dust at his work place. Within 3 mo of being employed in a factory processing Quallaja bark to produce saponin, he experienced asthma symptoms while handling the bark but only nasal symptoms on being exposed to the purified saponin. Bronchial provocation using Quillaja bark dust resulted in immediate bronchoconstriction as well as faintness, diffuse erythema, and hypotension. Radioallergosorbent test (RAST) using the pulverized crude Quillaja bark was markedly positive, and cross-reactivity between gum acacia and gum tragacanth was demonstrated using this technique.

Adult↗
PubMed1981

Isolation and partial characterization of a major peanut allergen.

We isolated and partially characterized a major peanut allergen (Peanut-I) using the radioallergosorbent test (RAST) to monitor the allergenicity of various fractions. Raw peanuts were pulverized, defatted, and extracted; the resulting crude extract (CPE) was fractionated by diethylaminoethyl (DEAE) cellulose anion-exchange chromatography using a linear salt gradient. Peak allergenic fractions were further purified by a second DEAE cellulose chromatography step, followed by a preparative polyacrylamide gel electrophoresis (PAGE) step. The final product, Peanut-I, contained 11% nitrogen and 8.7% carbohydrate and was homogeneous by both analytical PAGE and immunoelectrophoresis against rabbit anti-CPE. Peanut-I was heterogeneous by thin-layer electrofocusing and by PAGE in 1% sodium dodecyl sulfate. Biologic activity of Peanut-I was demonstrated by positive skin tests and leukocyte histamine release assays in patients with peanut allergy. By RAST inhibition assay Peanut-I did not account for all of the allergenic activity of CPE.

Allergens↗
PubMed1991

Fabrication and biocompatibility of a porous bioglass ceramic in a Na2O-CaO-SiO2-P2O5 system.

A porous bioglass ceramic was prepared from a finely pulverized bioglass powder mixed with particles of two sizes (5 and 500 microns) of 30% by weight with the foaming agent polyethylene glycol 4000 (HO (C2H4O) nH). The batch composition of the bioglass was Na2O 12%, CaO 28%, SiO2 50% and P2O5 10% by weight. The specimens, formed by pressing, were sintered in a high temperature furnace. In this study we are concerned with the preparation and microstructure of the material and its performance in biological tests. The microstructure and crystalline phases of the material were investigated by differential thermal analysis, X-ray diffraction analysis, transmission electron microscopy and scanning electron microscopy. In a biomedical examination, it was shown that the porous material was compatible with animal tissues. The microstructure of the implant indicated that newly grown bone interlocked well with the glass ceramic and that macropores and micropores were distributed uniformly in the material, which provided channels for bone ingrowth and improved the microscopic bioresorption.

Animals↗
PubMed1986

Cytogenetic modifications of Friend leukemia cells resistant to adriamycin.

Chromosome analysis was performed on adriamycin-sensitive and resistant Friend leukemia cells. Resistance to ADM is associated with an increased number of metacentric chromosomes. With increasing level of drug resistance additional metacentric chromosomes and several chromosomal markers were observed. Furthermore, the C-banding patterns and the heterochromatin distribution differed in resistant, as compared to sensitive cells. When sensitive cells were exposed to a toxic dose of ADM, multiple chromosomal breaks were observed in 62% of cells. In contrast, when ADM resistant cells were exposed to cytotoxic concentrations, the pulverization phenomenon was not observed and 75-80% of cells were without breaks. This striking difference suggests a different mechanism for cytotoxicity in sensitive and resistant cells.

Animals↗
PubMed1992

Effects of coal gasification slag as a substrate for the plant Cyperus esculentus and the worm Eisenia fetida.

A further development of the coal gasification process will result in an increase of the amount of coal gasification slag (CGS). As yet little is known about the effects of storage in uncovered dumps. If there are any environmental effects, they are most likely caused by accumulation of metals from the CGS or by unacceptable physical properties of the CGS. Growth inhibition, mortality, and metal accumulation were analyzed for the plant Cyperus esculentus and the worm Eisenia fetida on CGS substrate. Pulverized fuel ash (PFA) was used as a reference. Both in the substrate and in tissues the concentrations of the cations Cu, Ni, Pb, and Zn and the anions As, B, Cr, Mo, Sb, and Se were determined. The availability of anions for C. esculentus and for E. fetida is greater in PFA than in CGS. The extent and rate of uptake of anionic metals by the plants is on the whole higher in the wetland situation. The availability of metals, expressed as the concentration factor (CF), in most cases appears to be smaller than 1 for nearly all elements. In E. fetida a CF greater than 1 was found only for the element As, in PFA substrate and 50% CGS. In C. esculentus a CF greater than 1 was found for B and Mo in the PFA substrate as well.

Animals↗