Inhibition enhancer of zeste homologue 2 promotes senescence and apoptosis induced by doxorubicin in p53 mutant gastric cancer cells

OBJECTIVES

Enhancer of zeste homologue 2 (EZH2) is crucially involved in epigenetic silencing by acting as a histone methyltransferase. Although EZH2 is overexpressed in many cancers and is involved in malignant cell proliferation and invasion, the role of EZH2 in senescence induced by DNA damage has up to now remained largely unknown. In this study, we sought to explore the outcome of EZH2 depletion along with exposure of doxorubicin (DOX), and related mechanisms, in gastric cancer cells.

MATERIALS AND METHODS

Here, senescence induced by DNA damage was achieved in gastric cancer cells by DOX treatment. EZH2 was downregulated by transfection with siRNA or treated with (-)-epigallocatechin-3-gallate, a targeted inhibitor. Senescence-associated β galactosidase (SA-β-gal) and formation of senescence-associated heterochromatin foci were used to identify cell senescence. To investigate effects of EZH2 depletion on the cell cycle, apoptosis and proliferation, flow cytometry and MTT analysis were employed. Changes in p53-p21 axis activation were detected by Western blotting.

RESULTS

We found that cell proliferative arrest caused by DOX could be promoted by EZH2 depletion. Mechanistically, EZH2 depletion not only worked in coordination with DNA damage during the progression of cell senescence but also promoted apoptosis in p53 mutant cells. However, it had no cooperative relationship with DOX in p53 wild-type cells.

CONCLUSIONS

These data help unravel a crucial role for EZH2 in senescence and apoptosis in gastric cancer cells and that p53 genomic status was associated with different cell responses to EZH2 silencing.

Diphenhydramine modulates cytokines and induces apoptosis in experimental acute pancreatitis

In this study, we investigated the therapeutic potential of diphenhydramine (DPH), a H(1) receptor antagonist, on taurocholate-induced acute pancreatitis and the underlying mechanisms involved. Rats were randomly divided into sham-operated, model, DPH-treated, octreotide-treated and the DPH plus octreotide combination therapy groups (n = 30 per group). Animals were sacrificed 3, 6 and 24 h after modeling and drug administration (n = 10 per time point) and sera, pancreas and lungs were harvested for further studies. DPH and octreotide monotherapy relieved histopathological injuries in multiple organs when compared to the model group. Combination therapy (DPH + octreotide) demonstrated better therapeutic potential than monotherapy. Data indicated that combination therapy had a better ability to reduce average mortality rates in rats, decrease the number of inflammatory cells, attenuate necrosis, upregulate the levels of amylase, TNF-alpha and IL-8 and downregulate the levels of IL-10 in the serum. Moreover, enhanced expression of Bax in the pancreas and lung were recorded suggesting a pro-apoptotic mechanism involved in the therapeutic potential of DPH. Our study demonstrated the therapeutic potential of DPH in acute pancreatitis and suggested a novel strategy for clinical management of this disease.

Association study of TRAF1-C5 polymorphisms with susceptibility to rheumatoid arthritis and systemic lupus erythematosus in Japanese

OBJECTIVE

The primary aim of this study was to investigate the association of polymorphisms of TRAF1-C5, a newly identified rheumatoid arthritis (RA) risk locus in Caucasians, with susceptibility to RA and systemic lupus erythematosus (SLE) in Japanese populations. Gene expression levels of TRAF1 and C5 to assess the functional significance of genotypes were also analysed.

METHODS

A multicentre association study consisting of 4 RA case-control series (4397 cases and 2857 controls) and 3 SLE case-control series (591 cases and 2199 shared controls) was conducted. Genotyping was performed using TaqMan genotyping assay for two single nucleotide polymorphisms (SNPs) that showed the best evidence of association in the previous Caucasian studies. Quantifications of TRAF1 and C5 expression were performed with TaqMan expression assay.

RESULTS

Significant differences in allele frequency for both SNPs were observed between RA and control subjects (combined odds ratio = 1.09), while no significant difference was detected between patients with SLE and controls. Interestingly, alleles rs3761847 A and rs10818488 G had increased the risk for RA in the present study, while they decreased the risk in the original studies. A significant difference was found between risk allele carriers and non-carriers of rs10818488 for the expression level of TRAF1 in phorbol myristate acetate-stimulated lymphoblastoid cell lines (p = 0.04).

CONCLUSION

Association of TRAF1-C5 locus with RA susceptibility was detected in the Japanese populations with modest magnitude, while no significant association was observed for SLE. Significant positive effect of genotype on the expression of TRAF1 might support the genetic association between TRAF1 and RA.

Expression and clinical significance of the stem cell marker CD133 in hepatocellular carcinoma

BACKGROUND

Although the primitive haematopoietic and neuronal stem cell marker CD133 is known to be present in cancer stem cells (CSCs) in hepatocellular carcinoma (HCC), the postresection prognostic impact of CD133 in HCC patients remains limited.

METHODS

Sixty-three resected specimens were collected from HCC patients. The expression of CD133 protein was analysed by immunohistochemistry and the association of CD133 expression with clinicopathological characteristics, tumour recurrence and survival of the patients was evaluated.

RESULTS

Immunohistochemical analysis of 63 HCC tissue specimens revealed that CD133 positive tumour cells were frequently present in HCC. Increased CD133 immunostaining was found in 26 specimens (41.3%). Increased CD133 expression levels were correlated with increased tumour grade, advanced disease stage, and elevated serum alpha-fetoprotein levels. Kaplan-Meier analysis indicated that patients with increased CD133 levels had shorter overall survival and higher recurrence rates compared with patients with low CD133 expression. Multivariate analyses revealed that increased CD133 expression was an independent prognostic factor for survival and tumour recurrence in patients with HCC.

CONCLUSIONS

These findings suggest that reactivated CD133 positive cells are frequently present in HCC. Additionally, increased CD133 expression corresponds with higher stage tumours in HCC, thus indicating a poor prognosis for patients. These data support the CSC hypothesis.

A novel tool for B-cell tolerance research: characterization of mouse alloantibody development using a simple and reliable cellular ELISA technique

In animal-based transplantation research, the measurement of anti-donor antibodies in transplant recipients is limited by lack of an appropriate technique. We have developed a novel immunoassay capable of quantifying antibody bound to cell-surface major histo- compatability complex (MHC) and non-MHC antigens, using splenocytes from wild-type and MHC-deficient mice as antigen-bearing target cells. We utilized our "cellular ELISA" (CELISA) technique to study the development of tolerance versus immunity in the B-cell compartment in response to neonatal exposure to allogeneic fetal liver cells (FLC). This neonatal tolerance protocol typically induces permanent acceptance of donor-type and third-party cardiac allografts, but rejection of both donor-type and third-party skin grafts occurs. C3H/He (C3H; H-2(k)) mice were injected as neonates with BALB/c (BALB; H-2(d)) FLC and transplanted as adults with C57BL/6 (B6; H-2(b)) cardiac grafts. Despite long-term acceptance of third-party B6 cardiac grafts, serum contained increased anti-B6 IgG and IgM levels as measured by CELISA; IgM production was elevated by 2 weeks posttransplant and remained stable, while IgG production increased rapidly between 2 and 5 weeks posttransplant. In another experimental setting, CELISA assays were able to detect that neonatal injection of C3H mice with FLC from wild-type B6 mice or from MHC class II-deficient or class I/II-deficient (B6 background) mice (CI(+)CII(+), CI(+)CII(-), CI(-)CII(-), respectively) prevented sensitization to B6 antigens by subsequent skin transplants but did not induce graft acceptance, whereas FLC from MHC class I-deficient-only (CI(-)CII(+)) did not prevent B6 sensitization. The CELISA technique is a simple and sensitive means for quantifying alloantibodies in mice and will assist in further delineating the role of the B-cell compartment in neonatally induced cardiac allograft acceptance.

Induction of human histo-blood group A antigen expression in mouse cells by gene therapy using lentiviral vectors harbouring human ABH-related glycosyltransferase genes

We recently discovered that ABO incompatibility, which evokes a rapid humoral immune response in adult heart transplantation, is not a barrier in infant heart transplantation, and that infant recipients of ABO-incompatible hearts develop specific B-cell tolerance to donor A/B antigens. An animal model of ABO-incompatible heart transplantation would allow detailed investigation of the mechanism(s) of acceptance of ABO-incompatible grafts, using experimental methods that would not be possible in humans. To determine the feasibility of such a model, the human alpha-1,2-fucosyltransferase (H-transferase; for H antigen expression) gene was cloned into a lentiviral vector, and the human alpha-1,3-N-acetylgalactosaminyltransferase (A-transferase; for A antigen expression) gene was cloned into a bicistronic lentiviral vector also containing the green fluorescent protein (GFP) gene; these replication-deficient vectors were denoted H-trs and A-GFP, respectively. Synthesis of the human histo-blood group A antigen in humans is dependent on expression of these two glycosyltransferases. HeLa cells, a human cell line known to be of blood group O origin, expressed cell surface A antigen as measured by cellular ELISA when transfected with A-GFP alone, and the level of A antigen expression was enhanced by transfection with H-trs in addition to A-GFP. Cell surface H antigen expression was observed on both mouse fibroblast and mouse endothelial cells only when infected with H-trs lentiviral particles. Expression of A antigen was dependent on infection with both H-trs and A-GFP lentiviral particles, approaching levels on human group A cells. These collective results indicate that expression of human histo-blood group A antigen at the cell surface can be induced in mouse cells by infection with H-trs and A-GFP, and that such A antigen expression is dependent on H-trs expression.

Injectable bone

Temperature-dependent polymerising polyethylene oxide hydrogel was used as a vehicle to deliver bone marrow mesenchymal cells by injection in six nude mice, four mice acting as controls, to study generation of new bone in the cell-hydrogel complex. Mesenchymal cells were harvested by in vitro cell culture, and cells were seeded into polyethylene oxide solution. The density of the suspension was adjusted to 5 x 10(7)ml(-1). The hydrogel was obtained by adjusting the temperature to over 6 degrees C. Aliquots of 0.5 ml of the cell-hydrogel complexes were injected subcutaneously into the backs of the six experimental mice, and 0.5 ml of hydrogel alone was injected into the four controls. Generation of new bone was studied by gross inspection, radiographs, and histological examination. Two months after injection hard nodes had formed subcutaneously in all six mice, whereas in the control group the hydrogel had been absorbed completely and only soft tissue was present at the site of injection. A shadow could be seen on the radiographs of all cell-seeded mice. On histological examination of the nodes there was trabecular bone and some areas of neocartilage. This method of generating new bone might be of potential clinical use.

[Combined surgery for cardiovascular disease and general thoracic lesions]

Surgical management of patients with concomitant critical cardiovascular disease and resectable general thoracic lesions is controversial. During a 16-year period (1985 to 2001), 15 patients underwent combined cardiovascular and general thoracic operations, of the 2,459 patients who underwent a cardiovascular operation requiring cardiopulmonary bypass at our institution. Patients had cardiovascular symptoms only and the general thoracic lesions were incidentally found by preoperative chest roentgenograms and/or computed tomography. Because of the cardiovascular disease, a pathological diagnosis was precluded before surgery. All except one descending thoracic aortic operation underwent concurrent pulmonary resection after neutralization of protamine following cardiovascular surgery requiring extracorporeal circulation. Lung pathology consisted of pulmonary bullae (n = 7), primary lung cancer (n = 4), benign lung tumor (n = 2), metastatic lung cancer (n = 1), and thymic cyst (n = 1). The pulmonary operations include bullectomy (n = 7), wedge resection (n = 6), lobectomy (n = 3), and removal of a thymic cyst (n = 1) including 2 staged procedures. The final diagnoses in 4 lung cancer cases were T1. N0M0, stage IA (n = 3) and T2N2M0, stage IIIA (n = 1). All malignancies including metastatic lung cancer, were able to be completely resected. The mean intraoperative bleeding volume for the cases was 997 +/- 221 ml, while mean duration of surgery was 382 +/- 31 minutes. Except for 2 cases required long term ventilatory support, the mean durations of tracheal intubation and ICU stay were 2.2 +/- 0.2 and 3.8 +/- 1.0 days respectively. Except for 1 surgical death, mean survival duration and 5-year survival rate were 59.7 +/- 12.5 (5-177) months and 66.3% respectively. These findings suggest that combined pulmonary resection with cardiovascular surgery is safe and offers a favorable prognosis to a selected group of patients.

Multiple lysosomal trafficking phenotypes in metastatic mouse mammary tumor cell lines

Although altered synthesis and trafficking of lysosomal proteins and their receptors are associated with a wide range of human and rodent malignancies, the basis for their involvement remains obscure. Here we describe findings on a set of mouse mammary tumor cell lines that we are using as a model to study the role of these proteins in oncogenesis and tumor progression. Three distinct proteinase-secreting phenotypes were identified among the metastatic cell lines of the set. Two phenotypes displayed a high level of secretion of cathepsin L and the third was characterized by elevated secretion of matrix metalloproteinase 9 (MMP-9). The two cathepsin L-secreting phenotypes were distinct in that they displayed differences in cathepsin trafficking, expression of mannose 6-phosphate/insulin-like growth factor receptor and expression of proliferin, a mannose-phosphorylated angiogenic factor. Although cells representing all three phenotypes are capable of dissemination to distant organs when implanted into mouse mammary glands, only cells with the MMP-9 phenotype were found to be capable of direct intravasation. These findings indicate that multiple proteinase-secreting phenotypes can arise from the same tumor and suggest that cathepsin L and other lysosomal proteins may play a role in dissemination of tumor cells via the lymphatic system.

[The cytotoxic effects of the adriamycin magnetic albumin microspheres combined with external magnetic fields on the malignant tumor cells]

This study sought to assess the inhibitory effects of the adriamycin magnetic albumin microspheres (ADM-MAMs) on Walker-256 malignant tumor cells in vitro induced by the permanent magnetic fields. The cultured Walker-256 cells were divided into three groups; the group of ADM-MAMs combined with magnetic fields, the group of AMD-MAMs without magnetic fields, and ADM group. The growth states of the cells were observed and photographed under the inverted microscope. The inhibitory rates(IR) were assayed by the modified MTT colorimetric method. The results showed that the IR of the ADM-MAMs group were similar to those of the ADM group (P > 0.05), but the group of ADM-MAMs combined with magnetic fields had obviously higher IR and significant changes of the cells' shapes. These findings indicate that the anticancer effect of ADM-MAMs on malignant tumor cells is similar to that of ADM, and such effect can be increased by the combined use of ADM-MAMs and external magnetic fields.

A study of injectable tissue-engineered autologous cartilage

OBJECTIVE

To test the effectiveness of the new techniques of tissue-engineered cartilage.

METHODS

Chondrocytes were harvested through type II collagenase digestion from the auricle of New Zealand rabbits. The cells were mixed with alginate to generate chondrocytes/alginate composites with final cellular density of 50 x 10(6) per mL. Calcium chloride was used as the cross-linking agent to gel the aqueous alginate solution. The chondrocytes/alginate composites were injected into the dorsal subcutaneous tissue of New Zealand rabbits through autologous cells grafts. The specimens were observed during cartilage formation at 4, 8, and 12 weeks after injection.

RESULTS

Prior to harvesting, chondrocytes/alginate composites were easily visualized under the dorsal skin of animals. The appearance of experimental specimens was similar to that of native cartilage in gross morphology. Using a standard hematoxylin and eosin stain, the histologic features of all experimental specimens demonstrated new cartilage formation. With a Masson's trichrome and safranin O stain, the presence of collagen and glycosaminoglycan (GAG) was observed at 8 and 12 weeks.

CONCLUSION

This study demonstrated that polymerization of alginate hydrogel can be controlled to allow injection of chondrocytes that produce new autologous cartilage at subcutaneous dorsal site of rabbits. Injectable tissue-engineered autologous cartilage is promising for potential use in oral and maxillofacial surgery.

Polysialyltransferase-1 autopolysialylation is not requisite for polysialylation of neural cell adhesion molecule

Polysialyltransferase-1 (PST; ST8Sia IV) is one of the alpha2, 8-polysialyltransferases responsible for the polysialylation of the neural cell adhesion molecule (NCAM). The presence of polysialic acid on NCAM has been shown to modulate cell-cell and cell-matrix interactions. We previously reported that the PST enzyme itself is modified by alpha2,8-linked polysialic acid chains in vivo. To understand the role of autopolysialylation in PST enzymatic activity, we employed a mutagenesis approach. We found that PST is modified by five Asn-linked oligosaccharides and that the vast majority of the polysialic acid is found on the oligosaccharide modifying Asn-74. In addition, the presence of the oligosaccharide on Asn-119 appeared to be required for folding of PST into an active enzyme. Co-expression of the PST Asn mutants with NCAM demonstrated that autopolysialylation is not required for PST polysialyltransferase activity. Notably, catalytically active, non-autopolysialylated PST does not polysialylate any endogenous COS-1 cell proteins, highlighting the protein specificity of polysialylation. Immunoblot analyses of NCAM polysialylation by polysialylated and non-autopolysialylated PST suggests that the NCAM is polysialylated to a higher degree by autopolysialylated PST. We conclude that autopolysialylation of PST is not required for, but does enhance, NCAM polysialylation.

[Investigation on Schistosoma japonicum infection in rodents in Yunnan Province]

OBJECTIVE

To investigate the role of rodents in the transmission of schistosomiasis in endemic areas in Yunnan Province.

METHODS

Kato-Katz method was used to study the infection rate of rodents, humans and domestic animals.

RESULTS

The infection rate was 0.9% (32/3,411) for rodents, 15.6% (461/2,964) for humans, and 9.6% (239/2,482), for domestic animals. The EPG(mean) was 5.8 for rodents, 1.8 for humans, 0.1 for cattle, 0.1 for horses and 0.02 for pigs.

CONCLUSION

The rodents played a minor role in the transmission of schistosomiasis in the plateau area of Yunnan province.

The relationship between apoptosis and the expression of proliferating cell nuclear antigen and the clinical stages in gastric carcinoma

The relationship between the apoptosis and the expression of proliferating cell nuclear antigen (PCNA) and the clinical stages in gastric cancers was studied. By using terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) technique and PCNA immunohistochemical staining, the apoptosis and the expression of PCNA in tissue of gastric carcinoma were assayed in situ, the index of apoptosis (AI), index of PCNA (PI) and the rate of AI/PI were calculated. AI and PI in gastric cancer tissues were (6.5 +/- 3.7)% and (49.8 +/- 15.9)% respectively, and the rate of AI/PI was 0.13 +/- 0.05, which were obviously different from those of normal gastric mucosa in paragastric cancer (P < 0.01). With the advanced TNM stages of gastric carcinoma, the AI was decreased, PI was increased and the rate of AI/PI decreased in gastric carcinoma. There was significant difference in them between the gastric cancer tissues and normal gastric mucosa in pericarcinoma in TNM stage II to IV (P < 0.05). It was suggested that the decreased apoptotic cells and the increased proliferating cells were obviously related to the tumor genesis and tumor progression in gastric carcinoma. The AI, PI and the rate of AI/PI would become the prognostic factors in advanced gastric carcinoma.

Toxicity of magnetic albumin microspheres bearing adriamycin

Magnetic albumin microspheres bearing adriamycin (ADM-MAM) is a novel chemotherapeutic compound with site-specific drug delivery characteristics. The acute and subacute toxic tests of the compound, local irritating test and anaphylactic test were performed on mice and guinea pigs. The results showed there was no macroscopically and microscopically direct cytotoxic injuries of the compound to the animal organs or to the cells. The LD50 value of the compound was higher than that of the single used adriamycin, indicating that the compound was less toxic than the single adriamycin and quite safe in its therapeutic dosage. Furthermore, there was also no side effects or toxic reactions to be observed on clinical patients with advanced carcinoma or gastric cancer.

In vivo oxidation-reduction kinetics of OxyR, the transcriptional activator for an oxidative stress-inducible regulon in Escherichia coli

The OxyR protein is a transcriptional activator for a subset of peroxide stress-inducible genes, most of which are involved in defense systems against oxidative stress. Recently, it was demonstrated that purified OxyR has one intramolecular disulfide bond, which led to the proposal that the reversible disulfide bond formation regulates the activity of OxyR as a transcription factor in response to peroxide stress. In this study, I demonstrated by SDS-PAGE under non-reducing conditions that an intramolecular disulfide bond is formed in OxyR upon exposure of the cells to hydrogen peroxide in vivo. Experiments using strains expressing mutant OxyR proteins with Cys to Ser single amino acids substitutions confirmed that the disulfide bond is formed between the Cys-199 and -208. Kinetic analyses indicated that the formation of the disulfide bond is rapid and transient, oxidized within 30 s and re-reduced within 5 min after the addition of hydrogen peroxide in the wild-type strain. These results provide evidence for the regulatory role of the reversible oxidation of dithiol to disulfide in sensing peroxide stress in vivo and signal transduction to the transcription apparatus by OxyR.

[Analysis and prevention of reoperation on congenital choledochal cyst]

OBJECTIVE

To investigate the reasons and prevention of reoperation on congenital choledochal cyst (CCC).

METHODS

The sex, age, cyst type, timing and method of operation were analyzed 22 reoperated (CCC) patients who underwent reoperation.

RESULTS

The reoperation rate was 24.4% (22/90). The gender age and cyst type were not related to reoperation rate (P > 0.05). Reoperation rate was correlated with the timing the modality and the manoeuvre of the surgery. The previous emergent surgery incurred higher reoperation rate than that of selective operation (P < 0.01). The reoperation rate was 88.9% in patients previously undergoing CCC extracorporeal drainage, it was 52.4% in group of internal drainage and 5.0% in group previously undergoing CCC resection (P < 0.01).

CONCLUSIONS

Congenital choledochal cyst should be treated by surgery in its early stage. Pradent policy should be adopted on the use of PTC and ERCP. Outer drainage was used as the first-aid measure; internal drainage should be abandoned; resection of the cyst with Roux-Y hepaticojejunostomy should be the therapy of choice.

[Experiment and clinical application of targeting treatment with adriamycin magnetic albumin microspheres in human gastric carcinoma]

OBJECTIVE

To study the pharmacokinetics in experimental animals and observe the concurrent anticancer effects in human advanced gastric cancer as an adjuvant chemotherapy, when adriamycin magnetic albumin microspheres (ADM-MAM) were combined with external static magnetic fields.

METHODS

The drug concentration of targeting tissues in the animals and the stability of ADM-MAM in human gastric juices were determined. Clinical and histopathological changes were observed in 55 cases of advanced gastric carcinomas after targeting treatment.

RESULTS

The peak concentrations of the targeting tissue were highest after ADM-MAMs were administered for 2 hours and remained at the high level for a long time. ADM-MAM maintained its stability in human gastric juices. Targeting treatment improved the patients' symptoms, raised the rated of tumor resection, prolonged patients' lifetime, and enhanced histopathological effects (P < 0.01).

CONCLUSIONS

The administration of ADM-MAM combined with the external static magnetic fields is effective for targeting location and is of clinical value as a preoperative adjuvant chemotherapy for human advanced gastric carcinoma.

Lysine-based structure responsible for selective mannose phosphorylation of cathepsin D and cathepsin L defines a common structural motif for lysosomal enzyme targeting

Previous studies have shown that lysine residues on the surface of cathepsins and other lysosomal proteins are a shared component of the recognition structure involved in mannose phosphorylation. In this study, the involvement of specific lysine residues in mannose phosphorylation of cathepsin D was explored by site-directed mutagenesis. Mutation of two lysine residues in the mature portion of the protein, Lys-203 and Lys-293, cooperated to inhibit mannose phosphorylation by 70%. Other positively charged residues could not substitute for lysine at these positions, and comparison of thermal denaturation curves for the wild type and mutant proteins indicated that the inhibition could not be explained by alterations in protein folding. Structural comparisons of the two lysine residues with those required for phosphorylation of cathepsin L, using models generated from recently acquired crystal structures, revealed several relevant similarities. On both molecules, the lysine residues were positioned approximately 34 A apart (34.06 A for cathepsin D and 33.80 A for cathepsin L). When the lysine pairs were superimposed, N-linked glycosylation sites on the two proteins were found to be oriented so that oligosaccharides extending out from the sites could share a common region of space. Further similarities in the local environments of the critical lysines were also observed. These results provide details for a common lysosomal targeting structure based on a specific arrangement of lysine residues with respect to each other and to glycosylation sites on the surface of lysosomal proteins.

[Living related liver transplantation: a case report]

OBJECTIVE

To study a case of living related liver transplantation.

METHOD

The patient was a 10-year-old girl who suffered from congenital diffuse intrahepatic cholangiectasis, recurrent cholangitis and hepatocirrhosis. The donor was the patient's father aged 40. The left lateral lobe of donor's liver was cut and grafted to the patient. Intensive care and treatment as well as follow-up were given after operation.

RESULT

For the donor, the operation lasted 400 min, with 410 ml bleeding and 300 g liver removed. The recovery was satisfactory. For the recipient, the operation lasted 652 min, with 1665 ml bleeding, 80 min non-liver stage, 0 min graft hot ischemic stage, and 137 min cold ischemic stage. Immunosuppressive therapy was given using cyclosporin A, azathioprine and adrenocortical hormones. There was an acute rejection 11 days after operation, which was controlled using hormone impulsive therapy. The patient has been surviving 7 months with normal liver function.

CONCLUSION

The living related liver transplantation is feasible under modern surgical conditions. It is demonstrated that perfect postoperative management is the key for the successful liver transplantation.

[Determination of the soluble non-starch polysaccharides in rice and wheat bran by gas chromatography]

Cereal polysaccharides can be broadly classified into two distinct and chemically well-defined types. They are the storage polysaccharides (alpha-glucan) and the structural polysaccharides starch (beta-glucan) which are usually called non-starch polysaccharides (NSP). The determination of soluble non-starch polysaccharides in rice and wheat bran by gas chromatography has been developed. The free sugars in the sample were extracted with 80% ethanol. The residue was hydrolyzed in an acetic acid buffer solution (pH 5.0) in the presence of amylase and amyloglucosidase to remove starch. The soluble NSP obtained was further hydrolyzed in the acidic condition to produce the corresponding monosaccharides which were derivatized to form alditol acetates for GC analysis with allose as the internal standard. The GC conditions were OV-1701 column (25 m x 0.3 mm) with temperature program from 195 degrees C to 225 degrees C and FID.

oxyR-dependent induction of Escherichia coli grx gene expression by peroxide stress

The Escherichia coli OxyR protein is a transcriptional activator for a number of genes induced in response to low concentrations of hydrogen peroxide. To identify additional OxyR-regulated genes, I cloned a DNA fragment that shows promoter activity regulated by OxyR by direct selection of OxyR-binding DNA fragments. Analyses of the cloned fragment indicate that the grx gene, encoding glutaredoxin 1, is inducible by hydrogen peroxide in an oxyR-dependent fashion.

Expression in Escherichia coli and purification of human thrombopoietin

Human thrombopoietin (TPO) has been successfully overexpressed in Escherichia coli, with an expression level of about 12% of total cellular protein. The full-length TPO gene was subcloned into the prokaryotic expression vector pKK233-2 under the control of the inducible tac promoter. The recombinant protein was produced mainly in the form of inclusion body. By efficient renaturation and one-step purification, the recombinant protein was purified to homogeneity. The specific activity and yield of recombinant TPO can reach 2 x 10(4) units/mg and 2 mg/g of wet E. coli cells respectively.

[Diagnosis and treatment of congenital choledochal cyst]

From January 1980 to June 1996, 82 patients with congenital choledochal cysts were treated and 76 of them were operated on B-ultrasonic diagnosis was made with a correct diaginostic rate of 93.9%. The total effective rate was was 78.4% after follow-up for 84 months. Resection of the cyst with Roux-Y hepaticojejunostomy was successful in 96.2% of the patients. Outer drainage was used as the first-aid measure. Cystoduodenostomy and cystojejunostoy which may lead to complications should be abandoned.

Mutagenicity of high fat diets in the colon and small intestine of transgenic mice

Dietary fat has been implicated as a cause of colon cancer by epidemiological studies. Unfortunately, these studies are compatible with high fat as either initiator or promoter. Since initiators are normally mutagenic, we have tested the mutagenicity of high fat diets in the intestinal epithelium at two loci. The Dlb-1 assay, used in the small intestine, detects a wide spectrum of mutations. The lacI assay (Big Blue Mouse assay) is not as sensitive to some types of mutation as is Dlb-1 but was used in the colonic epithelium. Mice suitable for both assays were fed isocaloric high fat diets and subsequently assayed for somatic mutation. The diets consisted of: (i) a mixture of beef tallow, butter and lard totalling to 31% w/w of the diet (AIN-76A) up to 17 weeks; and (ii) corn oil, beef tallow, lard or butter individually, at 31% w/w of the diet for 5 and 9 weeks. These diets provided 50% of the calories from fat. The weights of the experimental and control mice were similar throughout the experiment. No significant increases in mutant frequencies were observed on any high fat diet compared to controls, so we conclude that uncooked fats are not mutagenic and are not initiators of carcinogenesis in the intestinal epithelium.

Mapping of the OxyR protein contact site in the C-terminal region of RNA polymerase alpha subunit

The Escherichia coli OxyR protein requires the C-terminal contact site I region of the RNA polymerase alpha subunit for cooperative interaction with and transcription activation at OxyR-dependent promoters, suggesting direct protein-protein contact between OxyR and the C-terminal region of the alpha subunit. To determine the precise location of the OxyR protein contact site(s) in this region, we carried out mutational analysis of the 3' half of E. coli rpoA, the gene encoding the alpha subunit of RNA polymerase. We isolated a number of rpoA mutants defective in oxyR-dependent transcription activation at the E. coli katG promoter. Nucleotide sequence analysis of the rpoA gene from these mutants revealed that the mutations showing clear phenotypes are all clustered at two narrow regions (amino acid residues 265 to 269 and 293 to 300) within the C terminus of the alpha subunit. Reconstituted RNA polymerases containing the mutant alpha subunits were unable to respond to transcription activation in vitro at the katG, ahpC, and oxyX promoters by OxyR. These results suggest that these two regions comprise the contact surfaces on the alpha subunit for OxyR.

The transmission rate of the lacI transgene from the Big Blue mouse

Since transgenic mice are being used to analyze somatic and germinal mutation rates in vivo, it is of interest to know to what extent these mice are normal or abnormal in any way. During experiments designed to compare the mutational response of the transgene and an endogenous gene, Big Blue mice hemizygous for the transgene were bred to create a hybrid mouse in which the comparisons could be made. The fraction of these mice that inherited the transgene was 37% rather than the Mendelian expectation of 50%.