[Synthesis and antiinflammatory activity of 2-(E)-(4-hydroxy-3-methoxybenzylidene)-5-(N-substituted aminomethyl) cyclopentanones]

In search for new antiinflammatory agents, a series of 2-(E)-(4-hydroxy-3-methoxybenzylidene)-5-(N-substituted aminomethyl) cyclopentanones was synthesized via Stork reaction, Mannich reaction and amine exchange reaction. All of the fifteen target compounds were characterized by spectral analysis and elemental analysis. Preliminary pharmacological tests showed that several target compounds exerted appreciable effect on xylene-induced ear edema in mice and that alteration of the substituents of anilines showed significant influence on antiinflammatory potency.

Quantitative analysis of foveal retinal thickness in diabetic retinopathy with the scanning retinal thickness analyzer

PURPOSE

This study sought to measure foveal retinal thickness in patients with diabetic retinopathy and to investigate the relationship between foveal thickness and visual acuity, biomicroscopic findings, and angiographic features.

METHODS

A commercial scanning retinal thickness analyzer was used to measure retinal thickness. A laser slit was projected onto the retina and scanned in 400 milliseconds across the central area of the fundus. The image where the laser slit intersects with the retina was digitally recorded and analyzed. Retinal thickness was measured in 35 patients (35 eyes; patient age, 57 +/- 13 years) with diabetic retinopathy. Patients also were examined by fluorescein angiography and slit-lamp biomicroscopy to detect foveal thickening.

RESULTS

Linear regression analysis indicated a significant correlation between foveal thickness and visual acuity (adjusted R2 = 0.72, P < 0.001). Foveal thickness was abnormal in 6 (100%) of 6 eyes in which foveal thickening was detected with slit-lamp biomicroscopy. Foveal thickness also was abnormal in 9 (31%) of 29 eyes that appeared normal by biomicroscopic examination. Foveal thickness was 136 +/- 65 microns in 7 eyes without leakage, 175 +/- 35 microns in 13 eyes with questionable leakage, and 291 +/- 120 microns in 7 eyes with definite leakage (P = 0.0075).

CONCLUSIONS

Retinal thickness analysis is shown to be more sensitive than slit-lamp biomicroscopy for detecting small changes in retinal thickness. Retinal thickness analysis may prove to be a useful, noninvasive modality for the development or regression of macular edema.

[Distal spleno-caval shunt in 66 patients with portal hypertension]

OBJECTIVE

To evaluate the long-term results and operative experience of distal splenocaval shunt.

METHOD

66 patients with portal hypertension were treated by distal spleno-caval shunt. Of these patients 57 were males and 9 females with a mean age of 39 years. All the patients were followed up.

RESULT

The operative mortality rate was 7.58%. Only 5 patients experienced recurrent bleeding (7.58%). None of the patients had clinical hepatic encephalopathy. Five-year survival rate was 70.45%.

CONCLUSION

Distal splenocaval shunt is suitable for portal hypertension patients with hepatopetal portal flow.

The comparative trial of TCu 380A IUD and progesterone-releasing vaginal ring used by lactating women

The objective of this paper was to compare the efficacy, acceptability, safety, and bleeding pattern of TCu 380A intrauterine device (IUD) and progesterone-releasing vaginal ring used by breastfeeding women. The study population included 97 breastfeeding women using IUD and 100 women using vaginal ring. Of the IUD users, no insertion failure, perforation, or accidental pregnancy occurred in 12 months. There was one IUD expulsion. There were no discontinuations of IUD due to medical reasons other than expulsion. The total discontinuation rate was 2.3%. In the ring group, no accidental pregnancy occurred. The major reasons for discontinuation were ring use-related problems and vaginal problems. The total discontinuation rate was 65.4% within 1 year. The frequency of any one complaint among the ring users was higher than that among the IUD users. There were no differences in the proportion of women having no sexual activity and in the weight of their babies between the two groups. Compared with the IUD users, the median number of bleeding/spotting (B/S) episodes and B/S days of the vaginal ring users were fewer; consequently, the mean length of B/S-free interval was longer in all four reference periods; the mean length of B/S episode and segment were the same; the occurrence of amenorrhea was more frequent; in contrast, the proportions of normal bleeding patterns were fewer. The frequencies of prolonged bleeding, frequent bleeding, and infrequent bleeding patterns did not differ between the two groups. The percentage of irregular bleeding was fewer only in the first two reference periods. It is concluded that the TCu 380A IUD and progesterone-releasing vaginal ring used by breastfeeding women are safe and effective. The higher discontinuation rate of the ring users was mainly because of use-related problems. Breastfeeding women with TCu 380A IUD had better tolerance and acceptability. The TCu 380A IUD does not, but the progesterone-releasing vaginal ring does, suppress the recovery of ovarian function. However, once return of menstruation occurred, there were no differences in bleeding patterns between the two contraceptive methods.

[Synthesis and antiinflammatory activity of 2-(E)-benzylidene-5-(N-substituted aminomethyl) cyclopentanones]

Nineteen kinds of 2-(E)-benzylidene-5-(N-substituted aminomethyl) cyclopentanones were synthesized via Mannich reaction or amine exchange reaction and identified spectrometrically. One compound exhibited significant antiinflammatory activity, showing obvious inhibitory effect on xylene-induced mice ear swelling, carrageenin-induced rats paw edema and increased capillary permeability induced with acetic acid in mice. Its ED50 values in these inflammatory models were calculated to be 67.8 mg.kg-1, 25.3 mg.kg-1 and 41.8 mg.kg-1 respectively, nearly equal to those of ibuprofen and aspirin.

A phosphorylation site in the ftz homeodomain is required for activity

The Drosophila homeodomain-containing protein Fushi tarazu (Ftz) is expressed sequentially in the embryo, first in alternate segments, then in specific neuroblasts and neurons in the central nervous system, and finally in parts of the gut. During these different developmental stages, the protein is heavily phosphorylated on different subsets of Ser and Thr residues. This stage-specific phosphorylation suggests possible roles for signal transduction pathways in directing tissue-specific Ftz activities. Here we show that one of the Ftz phosphorylation sites, T263 in the N-terminus of the Ftz homeodomain, is phosphorylated in vitro by Drosophila embryo extracts and protein kinase A. In the embryo, mutagenesis of this site to the non-phosphorylatable residue Ala resulted in loss of ftz-dependent segments. Conversely, substitution of T263 with Asp, which is also non-phosphorylatable, but which successfully mimics phosphorylated residues in a number of proteins, rescued the mutant phenotype. This suggests that T263 is in the phosphorylated state when functioning normally in vivo. We also demonstrate that the T263 substitutions of Ala and Asp do not affect Ftz DNA-binding activity in vitro, nor do they affect stability or transcriptional activity in transfected S2 cells. This suggests that T263 phosphorylation is most likely required for a homeodomain-mediated interaction with an embryonically expressed protein.

Chronic administration of quinolinic acid in the rat striatum causes spatial learning deficits in a radial arm water maze task

Chronic intrastriatal administration of quinolinic acid (QA) in the rat produces a pattern of neurodegeneration similar to that seen in Huntington's disease (HD). Although these changes have been related to transient motor abnormalities, the effects of chronic QA administration on cognitive abilities have not been assessed. The present study investigated whether the striatal deterioration observed during chronic QA administration produces cognitive impairments in this animal model of HD by testing the effects of chronic administration of QA on spatial learning ability of rats in a radial arm water maze (RAWM) task. Rats were given bilateral implantation of a chronic dialysis probe apparatus which delivered either vehicle or QA (20 mM) into the striatum. Beginning 1 day after implantation, the rats were tested daily for 3 weeks in the RAWM. Nocturnal activity levels were also assessed at 1-, 3-, 5-, 7-, 14-, and 21-days following probe implantation. Results of behavioral testing indicated that chronic exposure to QA causes spatial learning deficits in the RAWM task with only a transient increase in activity levels. Collectively, these results suggest that chronic striatal exposure to QA mimics some aspects of the cognitive deficits observed in HD.

Novel somatostatin analogs for the treatment of acromegaly and cancer exhibit improved in vivo stability and distribution

The biodistribution of several radiolabeled somatostatin (SRIF) analogs was determined in the rat. Newly developed analogs BIM-23190 and BIM-23197 attained higher plasma levels and much greater target tissue concentrations than the clinically used BIM-23014 analog. Highest tissue concentrations of BIM-23190 and BIM-23197 were found in adrenal, kidney, pituitary and pancreas, tissues that are known to be abundant in mRNA for the somatostatin subtype 2 receptor. BIM-23190 and BIM-23197 associated radioactivity in these tissues was prolonged compared with that of BIM-23014, especially in the SRIF-receptor-rich pituitary. BIM-23190 and BIM-23197 were more stable in vivo and much less subject to biliary excretion than BIM-23014. These properties account for the elevated plasma and target tissue concentrations of these new SRIF analogs. Based on higher plasma levels, greater distribution to target tissues and longer in vivo stability, BIM-23190 and BIM-23197 may prove to be superior to BIM-23014 for the treatment of acromegaly and some types of cancer.

2-Deoxyglucose inhibits chemotherapeutic drug-induced apoptosis in human monocytic leukemia U937 cells with inhibition of c-Jun N-terminal kinase 1/stress-activated protein kinase activation

Human monocytic leukemia U937 cells undergo apoptosis when treated with antitumor drugs, such as etoposide, camptothecin and mitomycin C. The molecular mechanism of the drug-induced apoptosis is not well understood. In this study, we found that 2-deoxyglucose (2DG), an analog of D-glucose and an inducer of glucose-regulated stress, inhibited anticancer drug-induced but not tumor necrosis factor-alpha-induced apoptosis of U937 cells. 2DG did not reduce initial cellular damage caused by etoposide, an inhibitor of topoisomerase II, suggesting that 2DG affected subsequent cellular responses involved in apoptosis. 2DG inhibited the etoposide-induced activation of c-Jun N-terminal kinase 1/stress-activated protein kinase (JNK1/SAPK) and the subsequent activation of CPP32, both of which are positive regulators for etoposide-induced apoptosis of U937 cells. Our results indicate that 2DG inhibits apoptosis by blocking the signals from cellular DNA damage for JNK1/SAPK activation.

[Studies on the basis of molecular biology of the phase change of influenza A(H3N2) viruses]

The analysis of nucleotide sequences on HA1 domain of 35 strains of influenza A(H3N2) virus showed that their HA1 genes all were 984 nucleotides in length coding for a HA1 protein with 328 amino acids and there was not any occurrence of insertion or deletion of nucleotides on HA1 genes among them. The appearance of "O" phase strain of influenza A (H3N2) virus was closely related with substitution at 226 position of amino acid on HA1 protein molecule and the three-dimensional structural change of HA protein. The results in this paper indicated that the positions with multiple changes on HA1 protein molecule located at the top of HA protein, especially at antigenic determinant B site or receptor binding site. These further demonstrated that the substitution of amino acid on HA1 protein molecule was caused mainly by suppress of herd immunity. This study also showed that the position of the cysteine and proline residues on the HA1 protein molecule were conservative and that the glycosylation sites located at N and C terminals, especially at N terminal of the HA1 protein The significance of such a distribute delta of glycosylation sites in the evolution of viral genes and epidemiology still remain unknown.

Using gene carrier probability to select high risk families for identifying germline mutations in breast cancer susceptibility genes

Germline mutations in highly penetrant autosomal dominant genes explain about 5% of all breast cancer, and heritable mutations in the BRCA1 breast and ovarian cancer susceptibility gene account for 2-3% of breast cancer in the general population. Nevertheless, the presence of such mutations is highly predictive of disease development. Since screening for mutations is still technically laborious, we investigated whether the prior probability of being a carrier of a dominant breast cancer susceptibility gene in the youngest affected family member could be used to identify families in which the probability of finding a mutation is sufficiently high. Sixty German families with three or more cases of breast/ovarian cancer with at least two cases diagnosed under the age of 60 were screened for mutations by SSCP/CSGE and subsequent direct sequencing. Thirteen germline truncating/splicing mutations in BRCA1 were found in 33% (6/18) of the breast-ovarian cancer families and in 17% (7/42) of breast cancer only families. All the families showing mutations in BRCA1 had carrier probabilities of 0.65 or higher. In families with prior carrier probabilities above 0.6, the proportion detected was 0.46 in breast-ovarian cancer families and 0.26 in breast cancer only families. The average age at diagnosis of breast or ovarian cancer in families with BRCA1 mutations was 41.9 years and significantly lower than in families without mutations (p < 0.05). Mutation carriers and obligate carriers were also found to have cancers at other sites. The probability of being a susceptibility gene carrier, taking into account the complete pedigree information, allows uniform characterisation of all types of families for identifying those in which mutation analysis for BRCA1/2 is warranted. However, prior probabilities calculated using this method can be reduced when the correlation between genotype and phenotype is imperfect. A larger series of families needs to be investigated in this fashion to provide better estimates of the detection rate for different ranges of carrier probabilities.

[Studies on the solvent structure in protein crystals grown in microgravity]

Structures of Space- and ground-grown protein crystals were determined and compared for hen egg-white lysozyme and acidic phospholipase A2 from snake venom. The results show that microgravity might improve the structure of weakly bound ordered water molecules, though it could not change the protein conformation and the structure of solvent molecules bound stronger to protein molecules. The results also imply that the degree of quality improvement of microgravity-grown protein crystals might be related to the solvent content in protein crystals. These findings might, in a respect, reveal the mechanism of quality improvement of protein crystals grown in microgravity. In addition, due to the importance of water molecules in life activities, the confirmation of this preliminary conclusion might enlighten guidance in further studies of life science in microgravity.

Genetically recessive mutant of human monocytic leukemia U937 resistant to tumor necrosis factor-alpha-induced apoptosis

Tumor necrosis factor-alpha (TNF-alpha) is a cytokine that induces apoptosis in various cell systems by binding to the TNF receptor (TNFR). To study TNF-alpha-induced apoptosis, we isolated and characterized a novel TNF-alpha-resistant variant, U937/TNF clone UA, from human monocytic leukemia U937 cells. The UA cells resist apoptosis induced by TNF-alpha and anti-Fas antibody but not by anticancer drugs, such as VP-16 and Ara-C. Somatic cell hybridization between U937 and UA showed that apoptosis resistance to TNF-alpha in UA was genetically recessive. The hybridization analysis also showed that UA and another recessive mutant clone, UC, belong to different complementation groups in TNF-alpha-induced apoptosis signaling. In UA cells, TNF-alpha-induced disruption of mitochondrial membrane potential and CPP32 activation were abrogated. Expression of TNFR, Fas, and Bcl-2 family proteins was not changed in UA cells. These results suggest that the apoptosis resistant UA cells could have a functional defect in apoptosis signaling from the TNFR to mitochondria and interleukin-1beta converting enzyme (ICE) family protease activation. UA cells could be used to study signaling linkage between cell death-inducing receptor and mitochondria.

Preparation and Characterization of Surface-Covered Nanometer-Sized Catalyst by Carboxylate Phase Transfer

Surface-covered nanometer-sized CuO/Al2O3, CuO-ZnO/Al2O3, and CuO/ZnO catalysts were prepared by phase transfer with carboxylate. The surface-covered structure was studied using XPS, XRD, TEM, and high-resolution electron microscope. The results indicated that amorphous CuO and ZnO were dispersed on the surface of nanometer-sized Al2O3 particles in catalysts CuO-ZnO/Al2O3 and CuO/Al2O3, respectively. The thickness of its surface layer is about several angstroms. No spinel structure was found in the catalyst. The particle size of the surface-covered CuO/Al2O3 catalyst was about 2-3 nm. Al2O3 in the catalyst was amorphous. Surface-covered material CuO in the catalyst with low CuO content was also armophous. A large amount of copper carboxylate resulted in crystalline CuO and Cu2O. The protective ability of carboxylate to sol particles differs from the metal element of carboxylate. Copyright 1997 Academic Press. Copyright 1997Academic Press

Studies of cation binding in ZnCl2-regenerated bacteriorhodopsin by x-ray absorption fine structures: effects of removing water molecules and adding Cl- ions

The binding of Zn2+ in Zn2+-regenerated bacteriorhodopsin (bR) was studied under various conditions by x-ray absorption fine structures (XAFS). The 0.9:1 and 2:1 Zn2+:bR samples gave similar XAFS spectra, suggesting that Zn2+ might have only one strong binding site in bR. It was found that in aqueous bR solution, Zn2+ has an average of six oxygen or nitrogen ligands. Upon drying, two ligands are lost, suggesting the existence of two weakly bound water ligands near the cation-binding site in bacteriorhodopsin. When excess Cl- ions were present before drying in the Zn2+-regenerated bR samples, it was found that two of the ligands were replaced by Cl- ions in the dried film, whereas two remain unchanged. The above observations suggest that Zn2+ has three types of ligands in regenerated bR (referred to as types I, II, and III). Type I ligands are strongly bound. These ligands cannot be removed by drying or by exchanging with Cl- ions. Type II ligands cannot be removed by drying, but can be replaced by Cl- ligands. Type III ligands are weakly bound to the metal cation and are most likely water molecules that can be removed by evaporation under vacuum or by drying with anhydrous CaSO4. The results are discussed in terms of the possible structure of the strongly binding site of Zn2+ in bR.

Biophysical and mutagenic analysis of Thermoanaerobacter ethanolicus secondary-alcohol dehydrogenase activity and specificity

The Thermoanaerobacter ethanolicus 39E adhB gene encoding the secondary-alcohol dehydrogenase (secondary ADH) was overexpressed in Escherichia coli at more than 10% of total protein. The recombinant enzyme was purified in high yield (67%) by heat-treatment at 85 degrees C and (NH4)2SO4 precipitation. Site-directed mutants (C37S, H59N, D150N, D150Eand D150C were analysed to test the peptide sequence comparison-based predictions of amino acids responsible for putative catalytic Zn binding. X-ray absorption spectroscopy confirmed the presence of a protein-bound Zn atom with ZnS1(imid)1(N,O)3 co-ordination sphere. Inductively coupled plasma atomic emission spectrometry measured 0.48 Zn atoms per wild-type secondary ADH subunit. The C37S, H59N and D150N mutant enzymes bound only 0.11, 0.13 and 0.33 Zn per subunit respectively,suggesting that these residues are involved in Zn liganding. The D150E and D150C mutants retained 0.47 and 1.2 Zn atoms per subunit, indicating that an anionic side-chain moiety at this position preserves the bound Zn. All five mutant enzymes had </= 3% of wild-type catalytic activity, suggesting that the T. ethanolicus secondary ADH requires a properly co-ordinated catalytic Zn atom. The His-59 and Asp-150 mutations also altered secondary ADH affinity for propan-2-ol over a 140-fold range, whereas the overall change in affinity for ethanol spanned a range of only 7-fold, supporting the importance of the metal in secondary ADH substrate binding. The lack of significant changes in cofactor affinity as a result of these catalytic Zn ligand mutations suggested that secondary ADH substrate-and cofactor-binding sites are structurally distinct. Altering Gly198 to Asp reduced the enzyme specific activity 2.7-fold, increased the Km(app) for NADP+ 225-fold, and decreased the Km(app) for NAD+ 3-fold, supporting the prediction that the enzyme binds nicotinamide cofactor in a Rossmann fold. Our data indicate therefore that, unlike the liver primary ADH,the Rossmann-fold-containing T. ethanolicus secondary ADH binds its catalytic Zn atom using a sorbitol dehydrogenase-like Cys-His-Asp motif and does not bind a structural Zn atom.

Glucose represses the lactose-galactose regulon in Kluyveromyces lactis through a SNF1 and MIG1- dependent pathway that modulates galactokinase (GAL1) gene expression

Expression of the lactose-galactose regulon in Kluyveromyces lactis is induced by lactose or galactose and repressed by glucose. Some components of the induction and glucose repression pathways have been identified but many remain unknown. We examined the role of the SNF1 (KlSNF1) and MIG1 (KlMIG1) genes in the induction and repression pathways. Our data show that full induction of the regulon requires SNF1; partial induction occurs in a Klsnf1 -deleted strain, indicating that a KlSNF1 -independent pathway(s) also regulates induction. MIG1 is required for full glucose repression of the regulon, but there must be a KlMIG1 -independent repression pathway also. The KlMig1 protein appears to act downstream of the KlSnf1 protein in the glucose repression pathway. Most importantly, the KlSnf1-KIMig repression pathway operates by modulating KlGAL1 expression. Regulating KlGAL1 expression in this manner enables the cell to switch the regulon off in the presence of glucose. Overall, our data show that, while the Snf1 and Mig1 proteins play similar roles in regulating the galactose regulon in Saccharomyces cerevisiae and K.lactis , the way in which these proteins are integrated into the regulatory circuits are unique to each regulon, as is the degree to which each regulon is controlled by the two proteins.

[Human papillomavirus type 16 E6 oncogene and expression of P53, RB and PCNA in human cervical carcinoma]

The aim of this study was to get some insights into the relationship between human papillomavirus type 16 E6 transforming gene and the expressed products of tumor suppressor gene, the P53, RB and proliferation cell nuclear antigen (PCNA) in human cervical carcinoma. 44 formalin-fixed paraffin-embedded cervical carcinoma sections were screened for P53, RB and PCNA by immunohistochemical assay with their monoclonal antibodies, and for the presence of HPV16 E6 ORF by in situ hybridization with HPV16 E6 DNA probe we have successfully labeled. The presence of HPV16 E6 gene was detected in 27 of 44 specimens (61.3%), including 8 of P53 protein positive (29.63%), 14 of RB protein positive (52.85%), and 20 of PCNA positive (74.07%). Of 17 HPV16 E6 negative cases, there were 7 of P53 protein positive (41.17%), 9 of RB protein positive (52.94%), 12 of PCNA positive (70.58%). There were no HPV16 E6 gene in control group. In positive cases PCNA only expressed in base cells. Our date indicated that HPV16 E6 ORF and PCNA had significantly related to cervical carcinoma. We could not find the relationship between HPV16 E6 ORF and P53, RB, PCNA in cervical carcinoma. There were some HPV16 E6-positive cases, obviously with strong P53, RB immunostaining in cytoplasm but not in nuclei, PCNA immunostaining was strong at the edge of the cervical carcinoma cells than in nuclear of them.

Effect of acute and repeated versus sustained administration of the 5-HT1A receptor agonist ipsapirone: electrophysiological studies in the rat hippocampus and dorsal raphe

The present study was aimed at examining the adaptation of presynaptic 5-HT1A autoreceptors in the dorsal raphe and of postsynaptic 5-HT1A receptors in the dorsal hippocampus during long-term administration of the 5-HT1A receptor agonist ipsapirone given either repeatedly or in a sustained fashion. Concurrent microiontophoretic application of ipsapirone did not attentuate the suppressant effect of 5-hydroxytyptamine (5-HT) on 5-HT neurons, but markedly decreased it when co-applied on CA3 pyramidal neurons in the dorsal hippocampus. Thus, ipsapirone acted as a full agonist in the dorsal raphe and as a partial agonist in the dorsal hippocampus. Ipsapirone (15 mg/kg/day, s.c. x 2 days) delivered by osmotic minipumps markedly decreased the firing activity of the dorsal raphe 5-HT neurons. After 14 days of treatment, there was a complete recovery of their firing activity and a desensitization of their somatodendritic 5-HT1A autoreceptors, as assessed using microiontophoretic applications of 5-HT and 8-hydroxy-2(di-n-propylamino)tetraline (8-OH-DPAT) onto 5-HT neurons. The same degree of desensitization was obtained when ipsapirone was administered with repeated injections (7.5 mg/kg b.i.d., s.c. x 14 days). In contrast, the two modalities of ipsapirone adminsitration left unaltered the responsiveness of CA3 pyramidal neurons to microiontophoretic applications of 5-HT and 8-OH-DPAT. In conclusion, long-term administration of ipsapirone most likely increases 5-HT neurotransmission by enhancing the tonic activation of postsynaptic 5-HT1A receptors. Therefore, the use of sustained release preparation of 5-HT1A receptor agonists should not alter their therapeutic effectiveness in anxiety and affective disorders since the same effects on 5-HT1A receptor functions were produced in this rat model by the sustained and the repeated modes of administration of ipsapirone.

c-Myc plays a role in cellular susceptibility to death receptor-mediated and chemotherapy-induced apoptosis in human monocytic leukemia U937 cells

Human monocytic leukemia U937 cells readily undergo apoptosis when they are treated with TNF-alpha, anti-Fas antibody and anticancer drugs such as etoposide and Ara-C. To study the mechanism of apoptosis, we developed a novel apoptosis-resistant variant, UC, from U937 cells. The UC cells showed resistance to apoptosis induced by TNF-alpha, anti-Fas antibody, etoposide and Ara-C. Somatic cell hybridization between U937 and UC showed that apoptosis-resistance to TNF-alpha in UC was genetically recessive and resistance to etoposide was dominant, suggesting that UC has at least two different mutations functionally involved in apoptosis. Mechanistic analysis revealed that UC cells expressed reduced amounts of c-Myc. Transfection of the c-myc gene into UC cells restored the sensitivity of the cells to undergo apoptosis induced by TNF-alpha and anti-Fas, which attributes apoptosis-resistance in this circumstance to the reduced expression of c-Myc. On the other hand, c-myc transfection into UC cells could not restore their sensitivity to etoposide- and Ara-C-induced apoptosis, arguing against the role of c-myc in chemotherapy-induced apoptosis. However, treating the parental U937 cells with antisense oligonucleotides designed to reduce c-Myc expression rendered the cells resistant to etoposide-induced as well as to TNF-alpha-induced apoptosis. These results indicate that the reduced expression of c-Myc in UC is strongly associated with the resistance to etoposide-induced apoptosis. Our finding that c-myc transfection into UC could not restore the sensitivity to etoposide-induced apoptosis, suggests UC could have a second mutation that confers resistance to etoposide-induced apoptosis in a genetically dominant manner. Taken together, our present results indicate that c-Myc plays a role in cellular susceptibility to death receptor-mediated and chemotherapy-induced apoptosis.

New spirostanol glycosides from Anemarrhena asphodeloides

Two new spirostanol saponins, named anemarsaponin F (2b) and G (4b), along with six known spirostanol saponins were obtained from the rhizomes of Anemarrhena asphodeloides Bunge. On the basis of spectral analyses and chemical evidence, the structures of 2b and 4b were established as neogitogenin 3-O-beta-glucopyranosyl-(1-->2) [beta-xylopyranosyl-(1-->3)]-beta-glucopyranosyl (1-->4)-beta-galactopyranoside) and lilagenin 3-O-beta-glucopyranosyl-(1-->2)-[beta-xylopyranosyl-(1-->3)]-beta- glucopyranosyl-(1-->4)-beta-galactopyranoside, respectively.

[Detection of human papillomavirus DNA sequence in esophageal carcinoma using polymerase chain reaction]

Human Papillomavirus (HPV) DNA sequence in 68 paraffin-embedded specimens of esophageal carcinoma collected from high-risk Shantou City was detected and typed by polymerase chain reaction (PCR) technique. The results showed a 66.18% (45/68) positive rate of HPV DNA. Among these esophageal carcinoma specimens, 44 out of the 45 positive specimens were squamous cell carcinoma and one was adenosquamous carcinoma. The HPV DNA types detected were mostly HPV-6, -11, and -16. HPV-6 DNA was found in 19 (27.94%) of the 68 specimens, HPV-11 DNA in 25 (36.76%) and HPV-16 in 19 (27.94%) specimens. Among these three types, the difference gave no statistical significance (P > 0.05). But HPV-18 DNA was detected in only 6 (8.82%) specimens and the HPV in other 6 specimens was unidentified. It should be noted that as many as 24 (53.33%) of the 45 positive cases had multi-infection (coinfection of 2 or 3 types). Our results suggested that a higher detectable rate of HPV DNA was found in Shantou City as a high-risk region and that HPVs might be closely associated with the pathogenesis of the esophageal carcinoma.