[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.

[Discovery of a novel reassortant H1N2 influenza virus]

Three strains of influenza A virus were isolated from patients suffering from influenza like disease in Railway Hygiene and Anti-epidemic Station of Taiyuan in January 1996. The identification results by serological method indicated that the isolates were different from H1N2 subtype of influenza A virus isolated from men in 1989 and 1992 and that their HA antigenicity was similar to that of A/RP/8/34 (H1N1) virus, but distinguishable from that of influenza A (H1N1) virus circulating in mans recently. The comparison of migration patterns of the RNA among the isolates, the A/PR//34 (H1N1) and the A/Wuhan/359/95 (H3N2) viruses revealed that the migration patterns of RNA 1-4 segments of the isolates were similar to those of A/PR/8/34 (H1N1) virus, but those of RNA 5-6 segments were indistinguishable from those of A/Wuhan/359/95 (H3N2) strain. However, the migration patterns of RNA 7-8 segments of the isolates were not only different from those of A/PR/8/34 (H1N1) virus, but also distingrasgable from those of A/Wuhan/359/95 (H3N2) strain. Therefore, it could be considered that the isolates were a novel reassortant H1N2 influenza A virus.

Establishment of doxorubicin-resistant human bladder cancer cell line (BUI-87/ADMR) and its mechanism of multidrug resistance

OBJECTIVE

To establish a doxorubicin-resistant human bladder cancer cell line, BIU-87/ADMR, and to study its biological characteristics and mechanism of drug resistance.

METHODS

A human bladder cancer cell line resistant to doxorubicin, BIU-87/ADMR, has been established in vitro by exposing BIU-87 parent cells to progressively increasing concentrations of the drug over a period of 8 months. The cell line has been characterized in terms of growth kinetics, morphology, cross-resistance to other anticancerous agents, pharmacokinetics of daunorubicin and expression of P-glycoprotein (P-gp) which is closely related to the MDR phenotype.

RESULTS

The BIU-87/ADMR cell line was 6.3 times more resistant to doxorubicin than the parent BIU-87. It exhibited cross-resistance to doxorubicin derivatives (epirubicin, daunorubicin), vincristine and etoposide, but not to cisplatin and mitomycin C. Compared to the parent cells, the resistant cells have a slower growth rate and lower confluent density. Unlike the parent BIU-87, about 75% of the BIU-87/ADMR cells showed a positive reaction with monoclonal antibody against P-gp, JSB-1. Intracellular drug accumulation studies with fluorescence spectrometry indicated that the resistance exhibited by the BIU-87/ ADMR line was mainly caused by an increased active efflux.

CONCLUSIONS

The results suggest that MDR is an important phenomenon in bladder cancer and that more than one pathway of MDR may be present in human bladder cancer cell lines. BIU-87/ADMR may be a useful model for the development of new chemotherapeutic strategies in overcoming drug-resistance in the treatment of bladder cancer.

[Effect of B16 cells transfected with IL-2 gene on mouse immunity]

IL-2 was introduced into mice B16 melanoma cell line by using retrovirus infection method. Both B16 and B16-IL-2 cells were treated with Mit C beforehand and were then inoculated intraperitoneally as vaccines in mice respectively. Hanks solution was used instead of the vaccine in the control group. The data showed that the tumor incidence rate was zero in the group receiving B16-IL-2 vaccine followed by B16 inoculation. However, incidence rate was 100% in both the B16 vaccine immunization group and in the control groups. Experiments also indicated that the proliferation of splenic lymphocytes induced by MLTR, the specific cytotoxicity of CTL against B16 cells, the activities of splenic NK, LAK, and the level of IL-2 secretion in mice immunized by B16-IL-2 were much higher than those in the mice immunized only with B16 cells as well as the controls. These data indicated that secretion of IL-2 in mice promoted specific and nonspecific anti-tumor immunity of mice. The theoretic basis was provided for IL-2-secreting tumor vaccine.

Severe myopia as a risk factor for progressive visual field loss in primary open-angle glaucoma

The optic nerve head in severely myopic eyes may be particularly vulnerable to glaucomatous damage. To study this hypothesis, we examined 122 primary open-angle glaucoma eyes with fair to good control of the intraocular pressure and a sign of baseline optic nerve damage. Then, parameters for the progression of the visual field defects were evaluated by multivariate analysis. A high mean intraocular pressure (p = 0.007) and a large refractive error (p = 0.023) were significant risk factors for subsequent visual field loss. A high baseline cup-to-disk ratio (p = 0.100) was a marginal risk factor. Nonsignificant parameters included patient age (p = 0.692), the use of beta-adrenergic antagonists (p = 0.384), gender (p = 0.831) and left versus right side (p = 0.977). When the refractive error was used to subclassify patients into severely myopic (< or = -4 dpt), mildly myopic (-0.25 to -4 dpt), or emmetropic and hyperopic (> or = 0 dpt), only severe myopia was a significant risk factor for progressive visual field loss. Severe myopia, but not mild myopia, is a significant risk factor for subsequent visual field loss in patients with primary open-angle glaucoma.

Mechanism of anti-beta-adrenoceptor antibody mediated myocardial damage in dilated cardiomyopathy

Antibodies against beta(1)-adrenoceptor can be detected in serum of patients with dilated cardiomyopathy (DCM), which have beta-agonist-like activity, and induce a positive chronotropic effect on cardiac myocytes by its persistence at full strength. Effects of the antibodies against beta-adrenoceptor from sera of patients with DCM on myocardial cytotoxicity and cytoplasmic free Ca(2+)-concentration ([Ca2+]i) were observed in the cultured single layer SD rat ventricular cells by using the cytotoxicity assay and fluorescent Ca(2+)-indicator fura-2/AM. The positive sera of the anti-beta-adrenoceptor antibodies from patients with DCM markedly enhanced myocardial [Ca2+]i. Betaloc, a beta(1)-receptor blocker, might inhibit the increase of the antibody-mediated myocardial [Ca2+]i, and the sera from healthy donors had no effect on myocardial [Ca2+]i. Our results suggest that the anti-beta-adrenoceptor antibody might increase myocardial [Ca2+]i and result in myocardial damage. The antibodies might activate receptor-gating Ca(2+)-channel, thereby causing myocardial [Ca2+]i rise and calcium overload. Early use of betaloc is recommended in the treatment of dilated cardiomyopathy.

Growth differentiation factor-9 is required during early ovarian folliculogenesis

Growth factors synthesized by ovarian somatic cells directly affect oocyte growth and function, but it is unclear whether oocyte-secreted factors play a reciprocal role in modulating somatic cell functions in vivo. During the functional analysis of members of the transforming growth factor-beta superfamily in mouse development, we have uncovered a new family member, growth differentiation factor-9 (GDF-9), which is required for ovarian folliculogenesis. GDF-9 messenger RNA is synthesized only in the oocyte from the primary one-layer follicle stage until after ovulation. Here we analyse ovaries from GDF-9-deficient female mice and demonstrate that primordial and primary one-layer follicles can be formed, but there is a block in follicular development beyond the primary one-layer follicle stage which leads to complete infertility. Oocyte growth and zona pellucida formation proceed normally, but other aspects of oocyte differentiation are compromised. Thus, GDF-9 is the first oocyte-derived growth factor required for somatic cell function in vivo.

[The effect of IL2 gene transfection on the growth and metastatic characteristics of muous B16 melanoma cells]

In order to investigate the antitumor effect of IL2 gene transfected tumor vaccine, gene transfected tumor cells which secrete IL2 in a comparatively sustained manner must be obtained. Their growth and metastatic characteristics must be identified. This study used the retrovirus infection method to introduce human IL2 cDNA into mouse B16 melanoma cells. Southern blot analysis confirmed the establishment of IL2-integrated B16 cells (B16-IL2). Northern blot also showed the expression of IL2 gene in mRNA level. IL2 secretion of B16-IL2 was comparatively stable for a period of 6 months with the highest production rate of 53u/ml. No obvious influence was observed on the morphology and growth of the tumor cells in vitro after the transfection of IL2-cDNA. But, their oncogenicity in vivo was reduced and the tumor growth induced by B16-IL2 cells was inhibited. Lung metastasis rate and extent was also reduced. This study laid the foundation for the preparation of an IL2-secreting tumor vaccine.

Characterization of the mononickel metallocenter in H134A mutant urease

A mutant form of Klebsiella aerogenes urease possessing Ala instead of His at position 134 (H134A) is inactive and binds approximately half the normal complement of nickel (Park, I.-S., and Hausinger, R. P.(1993) Protein Sci. 2, 1034-1041). The crystal structure of the H134A protein was obtained at 2.0-A resolution, and it confirms that only Ni-1 of the two nickel ions found in the native enzyme is present. In contrast to the pseudotetrahedral geometry observed for Ni-1 in native urease (where it is liganded by His-246, His-272, one oxygen atom of carbamylated Lys-217, and a water molecule at partial occupancy), the mononickel metallocenter in the H134A protein was found to possess octahedral geometry and was coordinated by the above protein ligands plus three water molecules. The nickel site of H134A urease was probed by UV-visible, variable temperature magnetic circular dichroism, and x-ray absorption spectroscopies. The spectroscopic data are consistent with the presence of Ni(II) in octahedral geometry coordinated by two histidylimidazoles and additional oxygen and/or nitrogen donors. These data underscore the requirement of Ni-2 for formation of active urease and demonstrate the important role of Ni-2 in establishing the proper Ni-1 coordination geometry.

[A study on the expression of three cytokine-receptors and airway hyperreactivity in asthmatics after specific provocation]

OBJECTIVE

In order to study the role of T and B lymphocytes activation in the pathogenesis of asthma.

METHOD

Pulmonary function tests were performed and percentages of three cytokine receptors and the levels of sIL-2R, sIgE and TIgE were measured in 31 allergic asthmatics and 12 healthy subjects before and after specific provocation.

RESULTS

It was found that the serum levels of sIL-2R (t = 5,719, 5,647 P < 0.01), TIgE were measured in 31 allergic asthmatics and 12 healthy (t = 6,306, 7,218 P < 0.01) and percentages of CD+23 (chi(2) -23.43, 18.56 P < 0.01) or CD+(25) (chi(2) = 27.59, 15. 28) cells were significantly higher in asthmatics after challenge than those in controls or in asthmatics before challenge as well; There were significantly negative correlations between sIL-2R and FEV1 or sGaw (r = -0.573, -0.426 P < 0.01), whereas positive correlations between sIL-2R and Raw or percent of IL-2R/CD+(25) cells (r = 0.417, 0.532 P < 0.01); TIgE and percent of Fc epsilon R II/CD+(23) cells (r = 0.603 P < 0.01), respectively.

CONCLUSION

These findings suggest that T cell activation, increased serum levels of sIL-2R and increased expression of CD+(25) or CD+(23) on cells, may lead to enhanced AHR in allergic asthmatics.

Microsurgical replantation of the avulsed scalp: report of 20 cases

Our 4-year experience with 20 patients who had suffered avulsion of 75 percent or more of the scalp is reviewed. All patients underwent replantation using microsurgical technique with 100 percent survival in 16, partial survival in 3, and failure in only 1 case. The emergency management and indications for replantation are demonstrated. The roles of sufficient preoperative preparation, generous debridement of damaged vessels, interpositional vein grafts, and the shortening of operative time in contributing to this success are emphasized. We developed a new surgical procedure called simultaneous vein grafts on donor and recipient sites in an effort to use less time in the anastomosis of interpositional vein grafts. Furthermore, we anastomosed the extra artery of the scalp to the vein on the recipient head when no suitable vein could be found. Intraoperative repair of the scalp sensory nerve and no postoperative use of any vasodilator or anticoagulant are discussed.

[Studies on relationship between toxicity of trichothecene toxin T-2 and its structure]

Toxic action of mycotoxin T-2 and its metabolite T-2 tetraol and deepoxy T-2; tetraol was studied by cytotoxicity and animal toxicity tests to explore the relationship between toxin T-2 and its structure. Restults showed that proliferation of LLC-PK1 cells and synthesis of DNA could be inhibited by both toxin T-2 and T-2 tetraol. Toxicity of toxin T-2 was 100 times greater than that of T-2 tetraol. There was no obvious toxicity to the proliferation of LLC-PK1 cells and synthesis of DNA in a dose of 10 mg/L deepoxy T-2 tetraol. But, toxin T-2 caused obvious damage in heart muscle and articular cartilage of chicken embryos, and T-2 tetraol and deepoxy T-2 tetraol in heart muscle, but not in articular cartilage. T-2 tetraol produced by hydrolysis of toxin T-2 had toxicity to certain extent, but its strength was significantly less than that of the latter. It suggests that the epoxide group in toxin T-2 played a determinant role for its toxicity. If epoxy cycle of the basic nucleus of the molecule is open, its toxicity will change significantly.

The role of arsenic-thiol interactions in metalloregulation of the ars operon

The ars operon of the Escherichia coli plasmid R773 that confers arsenical and antimonial resistance is negatively regulated by the ArsR repressor. ArsR residues Cys-32 and Cys-34 were previously identified as involved in induction by arsenite and antimonite, suggesting coordination between As(III) and the two cysteine thiolates. However, in small molecule thiolate-As(III) complexes, arsenic is frequently three-coordinate. A site-directed mutagenic approach was employed in a search for a third arsenic ligand. ArsR proteins with C32G, C34G, and C32G/C34G substitutions were active repressors, but were not inducible in vivo. In vitro, the altered repressor-ars DNA complexes could not be dissociated by inducers. Alteration of Cys-37 and Ser-43, residues located in or near the putative helix-turn-helix DNA-binding region of the protein, had no effect on the inducibility of the operon. While these results indicated that neither the thiolate of Cys-37 nor the hydroxyl oxygen of Ser-43 is required for induction, they did not eliminate either atom as a potential arsenic ligand. Another approach involved reaction with an alternative inducer, phenylarsine oxide, which can form only two coordinations. Phenylarsine oxide was shown to be as effective as or more effective than arsenite or antimonite in induction in vivo. In vitro, the organic arsenical was more effective than either arsenite or antimonite in dissociating the repressor-promoter complex. Thus, two ArsR-arsenic bonds are sufficient for induction. The interaction of ArsR proteins with As(III) was examined using a phenylarsine oxide affinity resin. ArsR proteins containing any two of the three cysteine residues Cys-32, Cys-34, and Cys-37 bound to the resin. Alteration of any two of the three resulted in loss of binding. Arsenic X-ray absorption spectroscopy of ArsR treated stoichiometrically with arsenite confirmed the average arsenic coordination as AsS3 These results suggest that all three cysteine thiolates are arsenic ligands, but binding to only two, the Cys-32 and Cys-34 thiolates, is required to produce the conformational change that results in release of the repressor from the DNA and induction.

Coexpression of mammalian cytochrome P450 and reductase in Escherichia coli

cDNAs for human cytochrome P450 2E1 and rat NADPH-cytochrome-P450 reductase were cloned separately and in tandem into bacterial expression vectors, and expression of the two proteins in Escherichia coli was monitored by immunoblotting, spectroscopy, and catalytic assays. The cDNAs were separated on the coexpression plasmid by 22 nucleotides, with the P450 cDNA preceding the reductase cDNA. P450 content in solubilized cell membranes, whether expressed alone or coexpressed with P450 reductase, was approximately 0.11 nmol/mg of protein, and approximately 0.8 nmol could be obtained per liter of culture. Reductase content was five- to sixfold greater than P450 content when coexpressed, but severalfold less than that obtained when expressed without the upstream P450 cDNA, indicating differences in both stability and translatability between the two proteins. Solubilized membranes from cells expressing both proteins catalyzed aniline hydroxylation, p-nitrophenol hydroxylation, and N-nitrosodimethylamine demethylation at rates equivalent to those obtained by combining P450 and reductase preparations; addition of purified reductase to these membranes did not augment the activity. However, in contrast to results obtained with P450 2E1 expressed in other heterologous systems, addition of rabbit liver cytochrome b5 to preparations catalyzing p-nitrophenol or N-nitrosodimethylamine oxidation did not increase turnover, and, although activity could be shown with unsolubilized membranes, oxidation of these substrates in vivo could not be demonstrated. Nonetheless, the ability to coexpress P450 and reductase in E. coli so as to generate a functional monooxygenase system in vitro enhances the utility of this organism for the expression and characterization of cloned P450 isoforms.

[Inferior mesocaval shunt]

The results of inferior mesenteric vein-inferior vena cava shunt coupled with splenectomy and gastroesophageal devascularization in 16 patients with cirrhotic portal hypertention were reviewed. The mean diameter of the shunt stoma was 6.46 +/- 0.78 mm, and the portal pressure decreased from 4.25 +/- 0.54 kPa to 3.39 +/- 0.41 kPa. Variceal bleeding stopped in all 16 patients with no severe postoperative complications. This procedure should preserve satisfactory portal perfusion to the liver, and technically is easier than other shunt procedures.

Ultra low temperature cryopreservation of somatic embryogenic cell line of foxtail millet [Setaria italica (L.) Beauv]

Ultra low temperature cryopreservation is one of the methods for preservation of biological material. Until now, a major problem of protoplast culture of Gramineae is the instability of state of the somatic embryogenic cell line. In our experiments, elements affecting the ultra low temperature cryopreservation of somatic embryogenic cell line were studied: components of cryopreserve solution, somatic embryogenic cell line of different subculture time, growth recovery of cryopreserved cell line, and their protoplast cultures. Results demonstrated that the ultra low temperature cryopreservation did not change the properties of protoplast culture, and by using the cryopreserve method, plating efficiency of protoplast culture of cryopreserved cell line was maintained or enhanced.

Transseptal methods for percutaneous balloon valvoplasty simultaneously with radiofrequency catheter ablation

Percutaneous balloon mitral valvoplasty (PBMV) and radiofrequency catheter ablation (RFCA) have been used in the treatment of mitral stenosis (MS) and supraventricular tachycardia. The techniques of PBMV and RFCA yield better results with the development of interventional cardiology, but there is no report about PBMV performed simultaneously with RFCA in the same patient. Seven patients with mitral stenosis and Wollf-Parkinson-White (W-P-W) Syndrome were successfully treated with PBMV and RFCA by transseptal methods. LA, LAP, mPG and mPA were decreased from 43.4 +/- 4.6mm, 21.8 +/- 6.8mmHg, 21 +/- 7.7mmHg and 45.7 +/- 16.5mmHg to 39.2 +/- 3.7mm (P < 0.05), 12.7 +/- 4.5mmHg, 12 +/- 3.7mmHg and 32.3 +/- 9mmHg (P < 0.01). MVA was increased from 0.96 +/- 0.33cm2 to 1.7 +/- 0.80cm2 (P < 0.01). delta wave disappeared in 12-lead surface EKG and SVT could not be induced in electrophysiological study after the treatment. The overall time of the procedure for this series was 93 +/- 34 minutes and fluoroscopy time was 23 +/- 7 minutes on the average. Radiofrequency energy applications were 3 +/- 2 times each procedure. PBMV and RFCA are safe and highly effective in the treatment of MS and W-P-W syndrome. The results in the present study proved the feasibility of the combined use of PBMV and RFCA. We prefer a first choice of PBMV and then RFCA in order to avoid aggravation of the hemodynamics due to mitral stenosis. The results also showed that of overall procedure and fluoroscopy only took a short time for this series. We suggest that it could be used as a routine method for the treatment of mitral stenosis complicated by W-P-W syndrome.

[Epoxide acrylate maleic resin and hydroxyapatite composite material as a bone graft substitute in surgical correction of orbital reconstruction]

This paper illustrates the results of surgical correction in 11 cases with orbital deformities such as periorbital deficiency after orbitotomy for retinoblastoma and orbital malposition after facial trauma. EH composite material, mixture of hydroxyapatite and epoxide acrylate maleic resin in constant proportion, was used as a good bone graft substitute in all 11 cases. This material was easier to be molded during surgery, safe to human body, had no toxic effects, no irritation and no implant-related complications. The early results obtained in these patients are encouraging.

[Evaluation and its clinical significance of anti-platelet granule membrane protein-140 autoantibodies and anticalmodulin antibody in patients with severe pregnancy-induced hypertension]

OBJECTIVE

To study the effect of immune function of platelet on the pathogenesis of severe pregnancy-induced hypertension.

METHODS

46 plasma samples from patients with severe pregnancy-induced hypertension (PIH) were evaluated for autoantibodies directed against granule membrane protein-140 (GMP-140) and anticalmodulin antibody (A-CaM) using ELISA methods.

RESULTS

Autoantibodies to GMP-140 existed in 13 patients with severe PIH (28.6%), after SDS-page of purified GMP-140 immunoblotting showed that 1 out of 8 sera from patients presented a staining band with M.W. of 140 kd. 29 plasma samples were found autoantibodies to GMP-140, GP IIb/IIIa and GP Ib/IX, simultaneously. It was shown that antiGMP-140 activities coexisted with anti-GP IIb/IIIa and/or anti-GPIb/Ix in 29 cases (81.8%). The elevated A-CaM was observed in the patients with severe PIH reaching to 20.02 +/- 3.74U/L, that was much higher than those from the normal (7.53 +/- 2.57U/L, P < 0.05).

CONCLUSION

Our study provided the evidence for autoantibodies to GMP-140 and A-CaM in some of patients with severe PIH, it has certain importance for further study on the pathogenesis of severe PIH.

Quantitative detection of amplification of proto-oncogenes in breast cancer

In the present study, dot-blot hybridization, serial dilution analysis and densitometric scanning were used to detect amplification of proto-oncogenes including c-erbB2, c-myc, int-2 and c-Ha-ras in 101 paraffin-embedded breast cancers. Expression of c-erbB2 was also examined by immunohistochemistry. Amplification of c-erbB2, c-myc and int-2 genes was found in 34.7%, 17.8% and 11.9% of breast cancers respectively. However amplification of c-Ha-ras was not detected in all cases. In 11.9% of cases co-amplification of two or more oncogenes was observed. Positive immunostaining of c-erbB2 was seen in 23.8% of the cases and it was significantly associated, but not always corresponding to the amplification of the gene. There was no difference between primary and metastatic breast cancer in the alterations of proto-oncogenes examined in this study, which suggested that the amplification and overexpression of these proto-oncogenes occurred prior to and maintained in the process of metastasis of breast cancer. Statistical analysis showed that high-scale of immunopositive staining of c-erbB2 and high-fold co-amplification of proto-oncogenes were significantly correlated with large size of the tumour and the number of involved lymph nodes. Our results indicate that the alterations of multiple oncogenes are involved in the development of breast cancer and some of them may have prognostic importance for breast cancer patients.