Synthesis of some new 2-alpha-L-arabinopyranosyl-1,2,4-triazines as potential antitumor chemotherapeutics

Synthetic routes towards different 2-alpha-L-arabinopyranosyl-3-thioxo-2,3-dihydro-1,2,4-triazin-5(4H)-/ones or thiones were investigated. Primary human anticancer screening of two selected compounds resulted in an active compound against SF-268 (CNS) cell line.     

MAPK mediates PKC-dependent contraction of cat esophageal and lower esophageal sphincter circular smooth muscle

Esophageal (ESO) circular muscle contraction and lower esophageal sphincter (LES) tone are PKC dependent. Because MAPKs may be involved in PKC-dependent contraction, we examined ERK1/ERK2 and p38 MAPKs in ESO and LES. In permeabilized LES muscle cells, ERK1/2 antibodies reduced 1,2-dioctanoylglycerol (DG)- and threshold ACh-induced contraction, which are PKC dependent, but not maximal ACh, which is calmodulin dependent. LES tone was reduced by the ERK1/2 kinase inhibitor PD-98059 and by the p38 MAPK inhibitor SB-203580. In permeable ESO cells, ACh contraction was reduced by ERK1/ERK2 and p38 MAPK antibodies and by PD-98059 and SB-203580. ACh increased MAPK activity and phosphorylation of MAPK and of p38 MAPK. The 27-kDa heat shock protein (HSP27) antibodies reduced ACh contraction. HSP27 and p38 MAPK antibodies together caused no greater inhibition than either one alone. p38 MAPK and HSP27 coprecipitated after ACh stimulation, suggesting that HSP27 is linked to p38 MAPK. These data suggest that PKC-dependent contraction in ESO and LES is mediated by the following two distinct MAPK pathways: ERK1/2 and HSP27-linked p38 MAPK.     

Cytotoxic benzophenanthridine and benzylisoquinoline alkaloids from Argemone mexicana

Fractionation of the chloroform extract from the aerial part of Argemone mexicana led to the isolation of two benzophenanthridine-type alkaloids, N-demethyloxysanguinarine and pancorine; three benzylisoquinoline-type alkaloids, (+)-1,2,3,4-tetrahydro-1-(2-hydroxymethyl-3,4-dimethoxyphenylmethyl)-6,7-methylenedioxyisoquinoline, (+)-higenamine and (+)-reticuline. Among them, N-demethyloxysanguinarine is a new compound, and (+)-1,2,3,4-tetrahydro-1-(2-hydroxymethyl-3,4-dimethoxyphenylmethyl)-6,7-methylenedioxy-isoquinoline was isolated form a natural source for the first time, to which was assigned a trivial name, (+)-argenaxine. In addition, six known non-alkaloidal compounds were also isolated and identified. All compounds were characterized on the basis of their spectral data and chemical evidences. Some isolated alkaloids from this species were evaluated for their cytotoxicity to human nasopharyngeal carcinoma (HONE-1) and human gastric cancer (NUGC) cell lines. Chelerythrine was found to exhibit significant activity against NUGC cell line, while angoline inhibited both types. (+)-Argenaxine showed moderate activity against the NUGC cell line.     

Response of cancer cells to molecular interruption of the CK2 signal

Protein kinase CK2 is one of the key cellular signals for cell survival, growth, and proliferation. It is has been observed to be elevated in various cancers that have been examined. Various observations suggest that moderate dysregulation of CK2 may profoundly influence the cell response. We have examined the effects of interfering with the CK2 signal in various cancer cell lines by employing antisense oligodeoxynucleotides (ODN) against the and subunits of CK2. Our results demonstrate that antisense CK2- and antisense CK2- ODNs markedly influence cell viability of these cancer cells in a dose and time-dependent manner. Antisense CK2- was slightly more effective than antisense CK2- in most of the cells tested. The efficacy of the antisense ODN seemed to vary with the cell type; however, in all cases potent induction of apoptosis was observed. Significantly, the effects of the antisense ODN on the CK2 activity in the nuclear matrix were relatively small compared to the much stronger induction of apoptosis in cells. This suggests that modest down-regulation of CK2 can evoke a much greater apoptotic response in cancer cells.     

Effect of amino acids on production of xylanase and pectinase from Streptomyces sp. QG-11-3

Xylanase and pectinase production by Streptomyces sp. QG-11-3 was stimulated by DL-norleucine, L-leucine, DL-isoleucine, L-lysine monohydrochloride and DL--phenylalanine by up to 3.72- and 2.78-fold, respectively, whereas the combination of DL-norleucine, L-leucine and DL-isoleucine synergistically stimulated the xylanase and pectinase production by up to 6.72- and 5.62-fold, respectively. Glycine, DL-norvaline, DL-methionine, and DL-aspartic acid showed no significant stimulatory effect on enzyme production.     

Noninvasive determination of hemoglobin and hematocrit using a temperature-controlled localized reflectance tissue photometer

We performed visible/near-infrared optical measurements on the forearm of human subjects. We conducted four studies: one study using a commercial diffuse reflectance spectrometer, and three studies using a breadboard temperature-controlled localized reflectance tissue photometer. Calibration relationships were established between skin reflectance signal and either the reference blood hemoglobin (Hb) concentration or the hematocrit values (Hct). Prediction results were expressed as the prediction correlation coefficient (r(p)) and the standard error for cross-validation prediction (CV-SEP). Using diffuse reflectance measurement, r(p) = 0. 8, CV-SEP = 0.9 g/dL for Hb and r(p) = 0.7, CV-SEP = 3.3% for Hct (n = 40). In a localized reflectance study involving calculating the absorption and scattering coefficients and including effect of change of skin temperature in the calibration model, the best prediction results were r(p) = 0.9, CV-SEP = 0.8 g/dL for Hb and r(p) = 0.8, CV-SEP = 3% for Hct (n = 26). In a second localized reflectance study on a population having diverse skin colors at 34 degrees C, the optimal model led to r(p) = 0.8, CV-SEP = 0.9 g/dL for Hb and r(p) = 0.9, CV-SEP = 2.1% for Hct (n = 28) using the localized reflectance values without deducing the absorption and scattering coefficients. Improvement in the correlation was more noticeable for Hct than for the case of Hb. The photometer was used to screen prospective blood donors with low Hb concentration. It was possible to predict anemic subjects in the limited prospective blood donor population.     

Macrophagelike vacuolated renal tubular cells in the urine of a male with osmotic nephrosis associated with intravenous immunoglobulin therapy. A case report

BACKGROUND: Osmotic nephrosis is a form of renal tubular injury that has been found in patients treated with intravenous immunoglobulin (IVIG). CASE: A 46-year-old male who had two courses of chemotherapy for acute myelogenous leukemia was found to have refractory thrombocytopenia. After IVIG (Sandoglobulin 12%, Novartis) administration (1 g/kg) for five consecutive days, the patient became oliguric and eventually anuric on the fifth dose. Hemodialysis was initiated, and urine production was noted on day 2 of hospitalization. Routine cytologic examination of fresh, voided urine showed numerous macrophagelike, bland epithelial cells with abundant, multivacuolated cytoplasm. Cytokeratin immunostain revealed positivity, thus confirming the epithelial origin of these cells. CONCLUSION: To our knowledge, this is the first such case reported in the English-language cytology literature. Awareness of a patient's clinical history may be helpful in avoiding an incorrect diagnosis. Urine cytology may be useful in obtaining an early diagnosis of osmotic nephrosis in patients receiving high-dose IVIG therapy that may eliminate the need for a renal biopsy.     

Demonstration of a fusion mechanism between a fluid bactericidal liposomal formulation and bacterial cells

It was previously demonstrated that fluid liposomal-encapsulated tobramycin, named Fluidosomes, was successful in eradicating mucoid Pseudomonas aeruginosa in an animal model of chronic pulmonary infection, whereas free antibiotic did not reduce colony-forming unit (CFU) counts (C. Beaulac et al., Antimicrob. Agents Chemother. 40 (1996) 665-669; C. Beaulac et al., J. Antimicrob. Chemother. 41 (1998) 35-41). These liposomes were also shown to be bactericidal in in vitro tests against strong resistant P. aeruginosa 64 microg/ml). The time needed to reach the maximal fusion rate was about 5 h for the resistant strain comparatively to much shorter time for the sensitive strain. The specific characteristics of Fluidosomes could help overcome bacterial resistance related to permeability barrier and even enzymatic hydrolysis considering the importance of synergy in the whole process of antibiotic resistance.