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PubMed1985

Orthotopic transplantation of the canine heart after prolonged preservation by simple immersion.

The viability of the heart was assessed following orthotopic transplantation. Following coronary vascular washout with cold potassium-verapamil cardioplegia, the heart was removed, immersed in the same solution, and stored at 4 degrees C for 24 hours in Group I (6 animals), 36 hours in Group II (5 animals), and 48 hours in Group III (3 animals). All six animals in Group I and four of five animals in Group II maintained a stable recipient circulation for the acute phase of 2 hours after transplantation, without cardiopulmonary bypass. For the dogs in Group III, cardiopulmonary bypass was vital. Contraction band injury after transplantation was more frequently observed in the Group II grafts than those of Group I. We conclude that the combination of coronary vascular washout with cold potassium-verapamil cardioplegia and storage at 4 degrees C in the same solution may preserve the canine heart for up to 24 to 36 hours, as demonstrated by post-orthotopic transplantation function.

Animals↗
PubMed1996

An improved method for rapid analysis of the fatty acids of glycerolipids.

An improved rapid procedure to determine the fatty acid composition of glycerolipids is described. The procedure includes KOH-catalyzed transesterification and high-speed gas chromatography. Glycerolipids (20-40 mg) were mixed with 2 mL of hexane and 0.2 mL of 2 M methanolic KOH at room temperature for 1-2 min. The fatty acid methyl esters in the hexane layer were analyzed by gas chromatography on 10% SP-2340 at 240 degrees C. Methyl linolenate and docosahexaenoate eluted within 2 and 5 min, respectively. Analysis was thus completed within 5 min for common vegetable oils and 8 min for fish oils.

Cholesterol Esters↗
PubMed1981

Effect of buffer constituents on rat liver 3-hydroxy-3-methyl glutaryl coenzyme A reductase.

Rat liver microsomes prepared in Tris buffer exhibited 3 to 10 times higher 3-hydroxy-3-methyl glutaryl CoA reductase specific activity than microsomes prepared with potassium phosphate buffer. This higher activity was observed in rats killed during mid-light cycle, but microsomes from rats killed during mid-dark cycle showed no significant difference in enzyme activity between buffers. When microsomes prepared in the 2 different buffers were preincubated with ATP and MG++, enzyme activity was inhibited to the same extent. The cytosol fraction in each of the 2 different buffer preparations possessed similar phosphatase activity. The higher 3-hydroxy-3-methyl reductase activity in Tris buffer, therefore, does not appear to be due to differences in phosphorylation or dephosphorylation activity.

Adenosine Triphosphate↗
PubMed1995

Phospholipid profiling of sediments using phosphorus-31 nuclear magnetic resonance.

A phosphorus-31 nuclear magnetic resonance method has been developed for the determination of aquatic sediment phospholipid profiles that may be generally applied to all soils and deposits containing viable cellular material. A method of scrubbing chloroform/methanol extracts with potassium acid phosphate overcomes adverse signal broadening from the mineral component, permitting eleven sediment phospholipids to be determined at the quantitative level.

Chloroform↗
PubMed1990

Analysis of cholesterol and desmosterol in cultured cells without organic solvent extraction.

Cultured cell sterols such as cholesterol and desmosterol are usually extracted into organic solvents before they are quantified with cholesterol esterase and oxidase. A method to quantify these cultured cell sterols using cholesterol enzymes without prior organic solvent extraction is described. In this method, a suspension or monolayer of cultured L-M, U-937, or PC-12 cells is digested with 0.1% sodium dodecyl sulfate (SDS), and the digest treated with microbial cholesterol enzymes. The quantity of oxidized sterols produced by the reaction can be measured easily with high-pressure liquid chromatography, when a mixture of sterols is present, or by the production of hydrogen peroxide when only one sterol is present. This method is easier and safer to use than solvent extraction and can greatly expedite the quantitation of cultured cell sterols. Preliminary data show that other lipids such as choline phospholipids, triglycerides, and fatty acids can also be directly quantified in SDS cell digest by using specific enzymes to transform these lipids into hydrogen peroxides.

Acetonitriles↗
PubMed1985

Vertebral bone mineral content in osteogenesis imperfecta.

Quantitative computed tomography of the lumbar spine was carried out in 28 patients with osteogenesis imperfecta (OI) in order to measure vertebral trabecular bone mineral concentration (BMC). The patients ranged in age from 6-73 years, and included 3 of the 4 major clinical subtypes of the disease. The findings underscore the heterogeneity of osteogenesis imperfecta even among family members with the same disease type. In addition, cross-sectional analysis of Type I OI patients suggests that BMC during young adulthood averages about 70% of normal, and subsequently falls more rapidly than in normal patients. BMC tends to be lower in the more severe forms of OI. Decreased BMC was not found in a few otherwise normal relatives with scoliosis or joint laxity.

Adolescent↗
PubMed1989

Production of acid and alkaline phosphatases by Myxococcus coralloides.

Acid and alkaline phosphatase of Myxococcus coralloides were examined during vegetative growth in a liquid medium. Two extracellular phosphatases and two cell-bound phosphatases, acid and alkaline in both cases, were produced. The phosphatase production was unaltered by the presence of high concentrations of inorganic phosphate. Both enzymes were produced constitutively. These two hydrolases were released into the growth medium during the exponential growth phase (approximately 10% of total activity). The production of these enzymes was modified by the presence of organic acids and metal ions in the medium.

Acid Phosphatase↗
PubMed1982

Buffering capacity of the chief components of nutritive media for algae.

The buffering capacity of solutions of KH2PO4 and NaHCO3 increases with their concentration, the behaviour being describable by mathematical expressions. Solutions of KH2PO4 prepared from tap water exhibit a buffering capacity higher by an order of magnitude than those prepared from distilled water. However, there is no difference between the buffering capacities of solutions of NaHCO3 prepared from tap and distilled water. Urea and NH4NO3 have almost no effect on the buffering capacities of solutions.

Bicarbonates↗
PubMed1983

Alkaloid production by Claviceps sp. SD-58; involvement of phosphatase isozymes.

Simultaneous reduction in alkaloid yield and level of phosphatases by high concentrations of phosphate was observed in Claviceps sp. SD-58. Tryptophan-induced culture showed an increase in alkaloid yield and the level of phosphatases. Phosphate caused repression of both acid phosphatase (isoenzyme I) and alkaline phosphatase (isoenzymes III and V).

Acid Phosphatase↗
PubMed1982

Effects of nutrients present in bold's basal medium on the green alga Stigeoclonium pascheri.

The effects of varying concentrations of nutrients present in Bold's basal medium on the extent of colony formation from vegetative fragments, sporulation and spore germination of the green alga Stigeoclonium pascheri were studied. A decrease of colony formation was observed in media deficient in MgSO4, NaNO3, phosphates, and containing a 10-fold increase of H3BO3. Sporulation decreased in the same media. However, sporulation was greater in an increasing order in media containing 2- to 10-fold increase in MgSO4. There was a decrease in spore germination in media deficient in phosphates, MgSO4, containing 5- or 10-fold MgSO4, or containing 2- to 10-fold of CaCl2, H3BO3 or microelements. Spore germination increased in media containing 2-fold MgSO4, deficient in H3BO3 or microelements or containing none of the three micronutrient solutions.

Boronic Acids↗
PubMed1987

Factors influencing the activity of cellular alkaline phosphatase during growth and sporulation of Bacillus cereus.

Alkaline phosphatase (EC 3.1.3.1) is synthesized in media with a low phosphate concentration (0.37 mM of total and 19 microM of inorganic phosphate, respectively) already during the exponential phase of growth of Bacillus cereus. The enzyme is repressed by higher phosphate concentrations (3.7 mM) during the whole growth period; during sporogenesis the enzyme activity in cells slightly increases even under these conditions. During growth the enzyme is not secreted into the medium, a minor amount being released after cessation of growth. The enzyme activity can be increased by adding Zn2+ ions (10 microM). When during growth without phosphate the pH of the medium decreases below 5.0, the enzyme activity temporarily decreases and growth is slowed down, followed by a subsequent increase of the enzyme activity. In this case the onset of sporulation is also delayed.

Alkaline Phosphatase↗
PubMed1993

Improvement of culture conditions for L-proline production by a recombinant strain of Serratia marcescens.

Serratia marcescens SP511 was previously reported to be an L-proline-producing strain that harbors a recombinant plasmid carrying the mutant type of the proline operon. This strain produced 65 g/L of L-proline in a medium containing 22% sucrose and urea after 5 d of incubation under the conventional culture conditions. We searched for more suitable culture conditions for more abundant L-proline production by SP511. To improve the supply of a nitrogen source to cells, ammonium was used instead of urea and fed to a culture under control of the pH of the medium. The concentrations of MgSO4 and K2HPO4 were increased, and in addition, sucrose was continuously added to the culture at a final concentration of 32%. Under these conditions, the cell amount was increased twofold over that under the previous conditions and L-proline production reached a maximum of more than 100 g/L after 4 d of incubation.

Ammonia↗
PubMedDate not supplied

The in vitro transformation of a rat liver epithelial cell line with chromium.

The transformation of a rat liver epithelial cell line under a wide range of doses of chromium was determined by anchorage-independent growth and tumor formation in syngeneic animals. Chronic exposure to low concentrations and brief exposure to high concentrations of hexavalent chromium (K2CrO4) transformed the cells, but one dose (1 mM K2CrO4, 2 h) was clearly optimal in this regard. The cytotoxicity, effects on cell cycle, rates of chromium uptake, and mutagenic activity under the different treatment conditions were evaluated. The results showed that cells could adapt to the presence of chromium under certain treatment conditions, but this was not the case for the optimal transforming dose. Cells treated with chromium above the optimal transforming dose showed evidence of a transient G2 arrest, whereas all lower levels of treatment did not. A low level continuous exposure to chromate was mutagenic, whereas high level short exposures, including the optimal transforming dose, were not. An increase in the amount of protein complexed with isolated nucleic acids was detected in cells following treatment with the optimal transforming dose of chromate. The results indicate that the effects of chromium on this in vitro system vary with dose, and the identification of those events relevant to metal carcinogenesis will require consideration of treatment conditions.

Animals↗
PubMedDate not supplied

Neoplastic transformation of BALB/3T3 cells by metals and the quest for induction of a metastatic phenotype.

In the mouse embryo cell line BALB/3T3 Clone A31-1-1, dose-dependent morphologic neoplastic transformation was obtained with NaAsO2, Na2HAsO4, CdCl2, and K2CrO4. Cellular uptake was four fold higher for As3+ than for As5+, and As5- was metabolized to As3+ in cytosol. Cytotoxicity and transformation rates were four fold higher for As3+ than As5+, but when correlated to cellular As burden they were equivalent. As3+ appears responsible for the transforming activity. The foci transformed by metals (or by other carcinogens) gave rise to tumorigenic cell lines (sc sarcomas in nude mice), none of which, however, induced metastases when tested by sc or by iv injection in nude mice. Thus carcinogens change this aneuploid cell line from a preneoplastic stage to the expression of malignant growth but not of metastatic activity. Metastatic and type IV collagenolytic activities can be induced by transfection of the c-Ha-ras oncogene and inhibited by the Ad2-E1a gene (so far shown in other cell types). It remains to be seen whether metal or other carcinogens can induce the nonmetastatic phenotype to become metastatic. The molecular mechanisms of metal carcinogenesis, studied in cell culture systems, in combination with other factors or oncogenes, may reveal the effect of individual metal carcinogens on discrete steps of the complex process of carcinogenesis.

Animals↗
PubMed1994

An XRF study of trace elements accumulation in kidneys of tumor-bearing mice after treatment with cis-DDP with and without selenite and selenocistamine.

The effect of cis-DDP treatment with and without selenite and selenocistamine was studied on kidneys of tumor-bearing mice. The amounts of cis-DDP, selenite, and selenocistamine injected were chosen so as to be compatible with the treatment of humans. The animals were sacrificed at 7, 14, and 28 d after treatment. The kidneys were removed and subjected to trace element analysis by a novel X-ray fluorescence (XRF) method and for pathological assessment. The results show that following treatment with cis-DDP, K, Fe, Cu, and Zn reach a maximum level after 7 d; K, Fe, and Cu levels were significantly reduced by the addition of selenite. The level of Zn was reduced only in groups treated with selenite whereas that of K and Cu was reduced also in groups treated with selenocistamine with and without cis-DDP. The greatest increase in Pt and Se levels was reached 1 wk after injection with cis-DDP, with and without selenocompounds, and in the case of Pt was partly reduced by addition of selenite. Se returned to control values 2 wk after injection, although Pt was still high in all groups 2 and 4 wk after injection. The results corroborate the findings of our previous studies. The effect of selenocistamine in cis-DDP treated mice was partly insufficient. The pathological examination of the kidneys did not show any differences in the effect of various additives during the study.

Animals↗
PubMed1995

Comparison of fluid warmer performance during simulated clinical conditions.

The study evaluated the warming ability and flow rates associated with four fluid warming devices during pressure driven infusion and during wide open gravity driven roller clamp infusion. Warmers tested were the Astotherm, Flotem IIe, Level 1 System 250 and a modified cardioplegia heat exchanger. Fluids tested were crystalloid, red cells diluted with 200 ml, 0.9% saline, and undiluted red cells. The volume of fluid and outlet temperatures (point where i.v. tubing would be attached to the patient) were measured for each fluid and compared among warmers for each flow rate condition. For pressure driven infusion of red cells and crystalloid, the System 250, and modified heat exchanger delivered warmer fluids (33-35 degrees C) at higher flow rates (160-740 ml.min-1) than the Astotherm and Flotem (23-31 degrees C, 44-268 ml.min-1, P < 0.05). For gravity driven infusion, the System 250 delivered the warmest fluids (33-36 degrees C, P < 0.05) compared with the modified heat exchanger (29-35 degrees C), Astotherm (26-32 degrees C) and Flotem (26-27 degrees C). In conclusion, the modified heat exchanger and System 250 were moderately effective (outlet temperature > 32 degrees C) in warming crystalloid and red cells at pressure driven flow rates. Only the System 250 warmed red cells > 35 degrees C at gravity driven flow rates. The Flotem and Astotherm were not effective in warming rapidly infused solutions. None of the warmers tested was able to deliver fluids at normothermia (> 36.5 degrees C).

Blood↗