Sensitivity of cultured rat hepatocytes to aflatoxin B1 and benzo(a)pyrene.

We have tested the sensitivity of a cloned rat hepatocyte line, RL-PR-C, to aflatoxin B1 and benzo(a)pyrene as a function of population-doubling level. The cells were much more sensitive to the cytotoxic action of these agents subsequent to 230 population doublings. This sensitivity corresponded to the enhanced inducibility of aryl hydrocarbon hydroxylase activity by 3-methylcholanthrene.     

Sensitivity of cultured rat hepatocytes to aflatoxin B1 and benzo(a)pyrene

Summary We have tested the sensitivity of a cloned rat hepatocyte line, RL-PR-C, to aflatoxin B₁ and benzo(a)pyrene as a function of population-doubling level. The cells were much more sensitive to the cytotoxic action of these agents subsequent to 230 population doublings. This sensitivity corresponded to the enhanced inducibility of arylhydrocarbon hydroxylase activity by 3-methylcholanthrene. Supported by Grants CA 21258 and CA 12056 from the National Cancer Institute.     

The subcellular distribution and partial characterization of cholinesterase activities of canine platelets.

The multiple cholinesterase activities in canine platelets have been investigated. Platelets were homogenized by rapid decompression under nitrogen, glass tube/Teflon pestle, and glycerol lysis techniques. Rapid decompression under nitrogen technique was found to be the most efficient and gentle method for cell disruption. Homogenates were subfractionated using sodium diatrizoate density gradients. Marker enzyme assays and pulse labeling experiments with 5-hydroxyl[14C] tryptamine and [125I] thrombin on prepared subcellular fractions confirmed that the soluble, plasma membrane and the granule-1 fractions were all in reasonably pure form. Furthermore, labeling of the plasma membrane with [125I] thrombin is cited as the first successful attempt at attaining significantly bound marker for this structure. Cholinesterase activity distributions measured in these fractions indicated that about 30% of the activity was present in the plasma membrane, 50% in granule-1 and 5% in soluble fractions. Kinetic data of cholinesterase activities obtained from intact platelets, plasma membrane preparations and platelet release supernatants indicated that they are strikingly similar.     

Fungi isolated from asthmatic homes in the Taipei area.

Indoor fungi in Taipei were surveyed during 1969-1974 using Sabouraud's agar plates. No remarkable yearly variation of fungal incidence was observed. The fungal population was found to be different from home to home. The dominant members were Aspergillus, Penicillium, Mycelia sterila, Oospora, Rhodotorula, Hormodendrum and yeasts. The order of frequency of fungi found indoors was quite different from that of outdoor fungi. The fungal spores were more numerous during summer months, and this trend was more apparent for Aspergillus, Oospora, Rhodotorula, and Hormodendrum. The kind and the incidence of fungi found in asthmatic homes were not different from those detected in non-asthmatic homes, except that in asthmatic homes there were greater numbers of fungi.     

Effect of pH, carbamylation and other hemoglobins on deoxyhemoglobin S aggregation inside intact erythrocytes as detected by proton relaxation rate measurements.

Measurement of the transverse water proton relaxation rate has been used to study the effect of pH, carbamylation, and other hemoglobins on the aggregation of deoxyhemoglobin S inside intact erythrocytes. Upon complete deoxygenation, cyanate-treated ($\text{S}\text{S}$) erythrocytes and erythrocytes heterozygous with respect to hemoglobin S ($\text{A}\text{S}$, $\text{C}\text{S}$, and $\text{S}\text{D}$) have high transverse water proton relaxation rates very similar to the values obtained with homozygous ($\text{S}\text{S}$) erythrocytes. These results suggest extensive intermolecular interactions between deoxyhemoglobin S molecules and a resultant increase in the correlation time for the small fraction of “irrotationally bound” water. When the transverse relaxation rate in deoxygenated ($\text{S}\text{S}$) erythrocytes was measured as a function of pH, the maximum rate was observed between pH 7.0 and 7.5. Upon increasing the pH beyond this range the observed relaxation rate decreases as does the number of sickled cells. Upon decreasing the pH, the observed transverse relaxation rate also decreases but the ratio of values from $\text{deoxy}\text{oxy}$ ($\text{S}\text{S}$) erythrocytes remains in the normal range of 4–6 and the number of sickled cells does not change. Therefore, the deoxyhemoglobin S aggregate inside sickled erythrocytes, as observed by water proton relaxation rates, is not altered by carbamylation or by the presence of nongelling hemoglobins. In addition, the enhancement of the relaxation rates as a function of pH is consistent with the number of sickled forms observed.     

Impacts of benzophenone-type UV filters on cladoceran Daphnia carinata

Limnology - The impacts of three commonly used benzophenone-type UV filters including benzophenone (BP), 2-hydroxy-4-methoxy-benzophenone (BP3), and 2-hydroxy-4-methoxy-benzophenone-5-sulfonicacid...     

CHROMOSOME NUMBERS IN UMBELLIFERAE. V.

Chromosome numbers are reported for nearly 300 collections of Umbelliferae. Of these, 150 representing “new” or variant counts are figured. Karyotypes of fifteen of the genera included have apparently not been documented before.     

Assessing and improving the green performance using a compound approach

This study presents a compound approach with a five-phase process to assess and improve the green performance. Based on the Six Sigma approach, the five-phase process consists of definition, measurement, analysis, improvement and control (DMAIC) phases. During the first three phases, an evaluation the assessment model is developed based on the analytical hierarchy process. Particle swarm optimization is also performed to search for the sequence of actions in order to improve the green performance based on the output of the assessment model. Managers can monitor the progress of the improvement plan during the control phase. A case study involving two global footwear manufacturers demonstrate the effectiveness of the proposed approach.     

Cardamonin induces G2/M arrest and apoptosis via activation of the JNK–FOXO3a pathway in breast cancer cells

Cardamonin (CD), a naturally occurring chalcone isolated from large black cardamom, was previously reported to suppress the proliferation of breast cancer cells. However, its precise molecular anti‐tumor mechanisms have not been well elucidated. In this study, we found that CD markedly inhibited the proliferation of MDA‐MB 231 and MCF‐7 breast cancer cells through the induction of G2/M arrest and apoptosis. Reactive oxygen species (ROS) plays a pivotal role in the inhibition of CD‐induced cell proliferation. Treatment with N‐acetyl‐cysteine (NAC), an ROS scavenger, blocked CD‐induced G2/M arrest and apoptosis in this study. Quenching of ROS by overexpression of catalase also blocked CD‐induced cell cycle arrest and apoptosis. We showed that CD enhanced the expression and nuclear translocation of Forkhead box O3 (FOXO3a) via upstream c‐Jun N‐terminal kinase, inducing the expression of FOXO3a and its target genes, including p21, p27, and Bim. This process led to the reduction of cyclin D1 and enhancement of activated caspase‐3 expression. The addition of NAC markedly reversed these effects, knockdown of FOXO3a using small interfering RNA also decreased CD‐induced G2/M arrest and apoptosis. In vivo, CD efficiently suppressed the growth of MDA‐MB 231 breast cancer xenograft tumors. Taken together, our data provide a molecular mechanistic rationale for CD‐induced cell cycle arrest and apoptosis in breast cancer cells.