[Identification of a protein interacting with apoptin from human leucocyte cDNA library by using yeast two-hybrid screening]

To screen the protein interacting with apoptin from human leucocyte cDNA library by using yeast two-hybrid system, four clones interacting with apoptin were identified. One of them was homologous with Nmi (N-Myc interaction protein). Cell co-immunoprecipitation showed that apoptin could bind to Nmi in mammalian cells. Apoptin mutants T1, T2 and T3 lacked the C-terminal 11 AA,33-46 AA and both,respectively. Apoptin mutants T2 and T3 failed to interact with Nmi, suggesting that its 33-46 AA was pivotal for the interaction. Apoptin mutant T1 still interacted with Nmi, suggesting that its C-terminal 11 AA was not essential for the interaction.

Cyr61, a member of CCN family, is a tumor suppressor in non-small cell lung cancer

Cysteine-rich protein 61 (Cyr61) is a member of a family of growth factor-inducible immediate-early genes. It regulates cell adhesion, migration, proliferation, and differentiation and is involved in tumor growth. In our experiments, the role of Cyr61 in non-small cell lung cancer (NSCLC) was examined. Expression of Cyr61 mRNA was decreased markedly in four of five human lung tumor samples compared with their normal matched lung samples. NSCLC cell lines NCI-H520 and H460, which have no endogenous Cyr61, formed 60-90% fewer colonies after being transfected with a Cyr61 cDNA expression vector than cells transfected with the same amount of empty vector. After stable transfection of a Cyr61 cDNA expression vector, proliferation of both H520-Cyr61 and H460-Cyr61 sublines decreased remarkably compared with the cells stably transfected with empty vector. The addition of antibody against Cyr61 partially rescued the growth suppression of both H520-Cyr61 and H460-Cyr61 cells. Cell cycle analysis revealed that both H520-Cyr61 and H460-Cyr61 cells developed G(1) arrest, prominently up-regulated expression of p53 and p21(WAF1), and had decreased activity of cyclin-dependent kinase 2. The increase of pocket protein pRB2/p130 was also detected in these cells. Notably, both of the Cyr61-stably transfected lung cancer cell lines developed smaller tumors than those formed by the wild-type cells in nude mice. Taken together, we conclude that Cyr61 may play a role as a tumor suppressor in NSCLC.

Respiratory virus infections in pediatric hematopoietic stem cell transplantation

Respiratory virus infections (RVI) have become an increasingly appreciated problem in the hematopoietic stem cell transplant (HSCT) population. A retrospective analysis of 274 patients undergoing 281 HSCT at St. Jude Children's Research Hospital from January 1994 through December 1997 was performed. Medical and clinical laboratory records were reviewed beginning at the onset of conditioning through the year following each HSCT, and the analysis was done for the first RVI only. Thirty-two (11%) of 281 HSCT cases developed a RVI during the first year post-HSCT. The most frequent cause of RVI was human parainfluenza virus type 3. Univariate analysis was performed to determine the association between risk factors and the cumulative incidence of RVI. Respiratory viruses are frequent causes of infections in the first year post-HSCT in the pediatric population. Only allogeneic transplant and the degree of acute or chronic graft versus host disease were found to be statistically significant risk factors for RVI.

Regulation of expression of murine transferrin receptor 2

Complementary and genomic DNA for the murine transferrin receptor 2 (TfR2) were cloned and mapped to chromosome 5. Northern blot analysis showed that high levels of expression of murine TfR2 occurred in the liver, whereas expression of TfR1 in the liver was relatively low. During liver development, TfR2 was up-regulated and TfR1 was down-regulated. During erythrocytic differentiation of murine erythroleukemia (MEL) cells induced by dimethylsulfoxide, expression of TfR1 increased, whereas TfR2 decreased. In MEL cells, expression of TfR1 was induced by desferrioxamine, an iron chelator, and it was reduced by ferric nitrate. In contrast, levels of TfR2 were not affected by the cellular iron status. Reporter assay showed that GATA-1, an erythroid-specific transcription factor essential for erythrocytic differentiation at relatively early stages, enhanced TfR2 promoter activity. Interestingly, FOG-1, a cofactor of GATA-1 required for erythrocyte maturation, repressed the enhancement of the activity by GATA-1. Also, CCAAT-enhancer binding protein, which is abundant in liver, enhanced the promoter activity. Thus, tissue distribution of TfR2 was consistent with the reporter assays. Expression profiles of TfR2 were different from those of TfR1, suggesting unique functions for TfR2, which may be involved in iron metabolism, hepatocyte function, and erythrocytic differentiation.

Impact of treatment on the outcome of acute myeloid leukemia with inversion 16: a single institution's experience

To identify treatment factors that may affect the survival of children with inv(16)(p13.1q22), we compared the outcomes of 19 patients with this genetic feature treated at our institution during two treatment eras. Nine patients were treated during era 1 (1980 to 1987), and 10 were treated during era 2 (1988 to 1996). All entered complete remission (CR) with induction therapy. Eight of the nine children treated in era 1 died, seven of relapsed leukemia. In contrast, three of 10 patients treated during era 2 have died, all of non-disease-related causes. Event-free survival (EFS) estimates were significantly higher for patients treated during era 2 than for those treated during era 1 (P = 0.03); the 6-year estimates were 70 +/- 15% (s.e.) and 11 +/- 7%, respectively. Era 2 treatment protocols differed from those of era 1 in their use of higher doses of cytarabine and etoposide during induction and consolidation chemotherapy and in their use of 2-chlorodeoxyadenosine (2-CDA). These results suggest that dose intensification of cytarabine benefits children with AML and inv(16), as is the case in adults. They also suggest that dose intensification of etoposide and addition of 2-CDA may also offer an advantage. This study underscores the dependence of the prognostic impact of cytogenetic features on the efficacy of treatment.

A microdialysis study of the novel antiepileptic drug levetiracetam: extracellular pharmacokinetics and effect on taurine in rat brain

Using a rat model which allows serial blood sampling and concurrent brain microdialysis sampling, we have investigated the temporal kinetic inter-relationship of levetiracetam in serum and brain extracellular fluid (frontal cortex and hippocampus) following systemic administration of levetiracetam, a new antiepileptic drug. Concurrent extracellular amino acid concentrations were also determined. After administration (40 or 80 mg kg(-1)), levetiracetam rapidly appeared in both serum (T(max), 0.4 - 0.7 h) and extracellular fluid (T(max), 2.0 - 2.5 h) and concentrations rose linearly and dose-dependently, suggesting that transport across the blood-brain barrier is rapid and not rate-limiting. The serum free fraction (free/total serum concentration ratio; mean+/-s.e.mean range 0.93 - 1.05) was independent of concentration and confirms that levetiracetam is not bound to blood proteins. The kinetic profiles for the hippocampus and frontal cortex were indistinguishable suggesting that levetiracetam distribution in the brain is not brain region specific. However, t(1/2) values were significantly larger than those for serum (mean range, 3.0 - 3.3 h vs 2.1 - 2.3 h) and concentrations did not attain equilibrium with respect to serum. Levetiracetam (80 mg kg(-1)) was associated with a significant reduction in taurine in the hippocampus and frontal cortex. Other amino acids were unaffected by levetiracetam. Levetiracetam readily and rapidly enters the brain without regional specificity. Its prolonged efflux from and slow equilibration within the brain may explain, in part, its long duration of action. The concurrent changes in taurine may contribute to its mechanism of action.

Biology and outcome of childhood acute megakaryoblastic leukemia: a single institution's experience

To describe the clinical and biologic features of pediatric acute megakaryoblastic leukemia (AMKL) and to identify prognostic factors, experience at St Jude Children's Research Hospital was reviewed. Of 281 patients with acute myeloid leukemia treated over a 14-year period, 41 (14.6%) had a diagnosis of AMKL. Six patients had Down syndrome and AMKL, 6 had secondary AMKL, and 29 had de novo AMKL. The median age of the 22 boys and 19 girls was 23.9 months (range, 6.7-208.9 months). The rate of remission induction was 60.5%, with a 48% rate of subsequent relapse. Patients with Down syndrome had a significantly higher 2-year event-free survival (EFS) estimate (83%) than did other patients with de novo AMKL (14%) or with secondary AMKL (20%; P < or =.038). Among patients who had de novo AMKL without Down syndrome, 2-year EFS was significantly higher after allogeneic bone marrow transplantation (26%) than after chemotherapy alone (0%; P =.019) and significantly higher when performed during remission (46%) than when performed during persistent disease (0%; P =.019). The 5-year survival estimates were significantly lower for de novo AMKL (10%) than for other forms of de novo AML (42%; P <.001). Treatment outcome is very poor for patients with AMKL in the absence of Down syndrome. Remission induction is the most important prognostic factor. Allogeneic transplantation during remission offers the best chance of cure; in the absence of remission, transplantation offers no advantage over chemotherapy alone. (Blood. 2001;97:3727-3732)

Phase-field simulations of dendritic crystal growth in a forced flow

Convective effects on free dendritic crystal growth into a supercooled melt in two dimensions are investigated using the phase-field method. The phase-field model incorporates both melt convection and thermal noise. A multigrid method is used to solve the conservation equations for flow. To fully resolve the diffuse interface region and the interactions of dendritic growth with flow, both the phase-field and flow equations are solved on a highly refined grid where up to 2.1 million control volumes are employed. A multiple time-step algorithm is developed that uses a large time step for the flow-field calculations while reserving a fine time step for the phase-field evolution. The operating state (velocity and shape) of a dendrite tip in a uniform axial flow is found to be in quantitative agreement with the prediction of the Oseen-Ivantsov transport theory if a tip radius based on a parabolic fit is used. Furthermore, using this parabolic tip radius, the ratio of the selection parameters without and with flow is shown to be close to unity, which is in agreement with linearized solvability theory for the ranges of the parameters considered. Dendritic sidebranching in a forced flow is also quantitatively studied. Compared to a dendrite growing at the same supercooling in a diffusive environment, convection is found to increase the amplitude and frequency of the sidebranches. The phase-field results for the scaled sidebranch amplitude and wavelength variations with distance from the tip are compared to linear Wentzel-Kramers-Brillouin theory. It is also shown that the asymmetric sidebranch growth on the upstream and downstream sides of a dendrite arm growing at an angle with respect to the flow can be explained by the differences in the mean shapes of the two sides of the arm.

Experience with 2-chlorodeoxyadenosine in previously untreated children with newly diagnosed acute myeloid leukemia and myelodysplastic diseases

PURPOSE

To develop more effective chemotherapy regimens for childhood acute myelogenous leukemia (AML).

PATIENTS AND METHODS

Between June 1991 and December 1996, we administered the nucleoside analog 2-chlorodeoxyadenosine (2-CDA) to 73 children with primary AML and 20 children with secondary AML or myelodysplastic syndrome (MDS). Patients received one or two 5-day courses of 2-CDA (8.9 mg/m(2)/d) given by continuous infusion. All patients then received one to three courses of daunomycin, cytarabine, and etoposide (DAV) remission induction therapy.

RESULTS

Seventy-two patients with primary AML were assessable for response. Their rate of complete remission (CR) was 24% after one course of 2-CDA, 40% after two courses of 2-CDA, and 78% after DAV therapy. Of the 57 patients who entered CR, 11 subsequently underwent allogeneic bone marrow transplantation (BMT), and 40 underwent autologous BMT. Twenty-nine patients remain in continuous CR after BMT. Two patients remain in CR after chemotherapy only. The 5-year event-free survival (EFS) estimate was 40% (SE = 0.080%). Patients with French-American-British (FAB) M5 AML had a higher rate of CR after treatment with 2-CDA (45% after one course and 70.6% after two courses) than did others (P =.002). In contrast, no patient with FAB M7 AML (n = 10) entered CR after treatment with 2-CDA. Similarly, no patient with primary MDS (n = 6) responded to 2-CDA. Seven patients with secondary AML or MDS (n = 14) had a partial response to one course of 2-CDA.

CONCLUSION

This agent was well tolerated, and its toxicity was acceptable. Future trials should examine the effectiveness of 2-CDA given in combination with other agents effective against AML.

A follow-up linkage study supports evidence for a bipolar affective disorder locus on chromosome 21q22

Evidence for linkage between bipolar affective disorder (BP) and 21q22 was first reported by our group in a single large pedigree with a lod score of 3.41 with the PFKL locus. In a subsequent study, with denser marker coverage in 40 multiplex BP pedigrees, we reported supporting evidence with a two-point lod score of 2.76 at the D21S1260 locus, about 6 cM proximal to PFKL. For cost-efficiency, the individuals genotyped in that study comprised a subset of our large pedigree sample. To augment our previous analysis, we now report a follow-up study including a larger sample set with an additional 331 typed individuals from the original 40 families, improved marker coverage, and an additional 16 pedigrees. The analysis of all 56 pedigrees (a total of 862 genotyped individuals vs. the 372 genotyped previously), the largest multigenerational BP pedigree sample reportedly analyzed to date, supports our previous results, with a two-point lod score of 3.56 with D21S1260. The 16 new pedigrees analyzed separately gave a maximum two-point lod score of 1.89 at D21S266, less than 1 cM proximal to D21S1260. Our results are consistent with a putative BP locus on 21q22.

Coxsackievirus-adenovirus receptor expression in ovarian cancer cell lines is associated with increased adenovirus transduction efficiency and transgene expression

The expression of coxsackievirus-adenovirus receptor (CAR) and the integrins alpha(v)beta3 and alpha(v)beta5 was analyzed quantitatively (flow cytometry) and qualitatively (immunocytochemistry) in five human ovarian cancer cell lines (PEO1, PEO4, PEO14, SKOV-3, and OVCAR-3) and three control cell lines (293, HeLa, and CHO-K1). The transduction efficiencies were evaluated by adv/rsv-beta-Gal transduction followed by X-gal staining. The effects of 17beta-estradiol on cell growth, CAR and integrins alpha(v)beta3/5 expression, adenovirus transduction efficiency, and cell-killing efficacy of adv/rsv-tk plus ganciclovir were determined. The levels of CAR, integrin alpha(v)beta3, and integrin alpha(v)beta5 showed great variation between the cell lines. Whereas the expression of CAR appeared to be essential for and positively correlated with adenovirus transduction efficiency, the integrins alpha(v)beta3 and alpha(v)beta5 were not absolutely necessary for adenovirus transduction even though their presence may facilitate transduction. In PEO4 and PEO1 cells, proliferation was stimulated by 17beta-estradiol in a dose-dependent manner. In PEO4 cells, and much less pronounced in PEO1 cells, this was accompanied by an increase in CAR expression. The stimulation of CAR expression was paralleled by an increased transduction efficiency resulting in an increased cell-killing efficacy. Our data suggest that the expression of CAR is one of the most important prerequisites for successful adenovirus-mediated gene therapy of ovarian cancer.

Propofol in subanesthetic doses terminates status epilepticus in a rodent model

Status epilepticus is commonly refractory to first-line therapy, and thus better treatments are needed. We have investigated an experimental model of drug-resistant self-sustaining status epilepticus (SSSE) induced by 2 hours of perforant path stimulation. Propofol in subanesthetic doses administered shortly after the end of stimulation and also after a further 3 hours of SSSE terminated the SSSE without recurrence. This finding calls for a trial of propofol in refractory status epilepticus and also raises the possibility of using it as first-line therapy.

Second malignancy after treatment of childhood acute myeloid leukemia

To investigate the cumulative incidence of second malignancy and the competing risk of death due to any other cause in patients who were treated for childhood acute myeloid leukemia (AML), we analyzed the outcomes in a cohort of 501 patients who were treated at St Jude Children's Research Hospital between 1970 and 1996. Five patients developed a second cancer (two carcinomas of the parotid gland, one non-Hodgkin's lymphoma, one supratentorial primitive neuroectodermal tumor, one acute lymphoblastic leukemia) as compared with 0.47 expected in the general population (standardized incidence ratio, 10.64; 95% confidence interval, 3.28 to 22.34). A third neoplasm (meningioma) developed in one patient. At 15 years after the diagnosis of AML, the estimated cumulative incidence of second malignancy was 1.34% +/- 0.61%, whereas the cumulative incidence of death due to any other cause was 72.96% +/- 2.14%. We concluded that although a more than 10-fold increased risk of development of cancer was found in survivors of childhood AML as compared to the general population, the risk of this late complication is small when compared to the much larger risk of death because of the primary leukemia or the early complications of its treatment. Future studies should focus on improving treatments for primary AML while preventing second malignancies.

Allogeneic bone marrow transplantation in children failing prior autologous bone marrow transplantation

Twenty-three children with de novo acute myelogenous leukemia (AML) (n = 20), secondary AML (n = 1), or non-Hodgkin's lymphoma (NHL) (n = 2) underwent allogeneic bone marrow transplantation (alloBMT) for graft failure (n = 1) or recurrent malignancy (n = 22) between February 1992 and August 1999 following autologous BMT (ABMT). Induction chemotherapy was given to 14 patients and nine patients went directly to alloBMT. Five received marrow from matched siblings, 14 from matched unrelated donors and four from mismatched family members. Conditioning regimens included cyclophosphamide, cytarabine, and total body irradiation. Nine patients are alive disease-free between 627 and 2433 days (1.7-6.7 years) post BMT resulting in a 4-year DFS of 39%. Eight patients relapsed at a median of 206 days (range, 35-669 days) post alloBMT and all eventually died. Eight patients (two of whom also relapsed) died of RRT. Although RRT and relapse remain significant problems, a significant percentage of pediatric patients failing ABMT may be cured with alloBMT.

[Study on relationship between estrogen receptor gene polymorphism and syndrome differentiation typing of female postmenopausal osteoporosis in Traditional Chinese medicine]

OBJECTIVE

To study the relationship between estrogen gene polymorphism and TCM Syndrome Differentiation of female postmenopausal osteoporosis in China.

METHODS

Two hundred and forty-six Chinese postmenopausal women, age 44-80 years, mean 65.8 years, using molecular biological method to analyze the endonuclease Pvu II, Xba I restriction fragment length polymorphisms (RFLPs), with dual X-ray bone mineral density absorption meter to determine the bone mineral densities of lumbar vertebra (L1-4) and femur (intertrochanter, femur neck, Ward's region) separately. The subjects were divided into Kidney Yin deficiency type, Kidney Yang deficiency type and both Kidney Yin-Yang deficiency type, to observe the relationship between TCM and bone density as well as estrogen receptor gene polymorphism, Pp(Pvu II) and Xx(Xba I) were used to express RFLPs, the capital P and X to express the deficit of restricting sites.

RESULTS

Bone mineral density of PPxx gene type (n = 21) was obviously lower than that of other gene types (n = 225), lumbar (-0.71 +/- 0.46) g/cm2, intertrochanter (-0.31 +/- 0.58) g/cm2, femur neck (-0.84 +/- 0.66) g/cm2, Ward's region (-0.96 +/- 0.85) g/cm2, the TCM Syndrome Differentiation typing of this gene type belonged to both Kidney Yin-Yang deficiency type.

CONCLUSION

Estrogen receptor gene RFLPs is related to TCM Syndrome Differentiation typing.

[Expression of beta 2 integrins and L-selectin on CML cells after treatment with IFN-alpha and allo-bone marrow transplantation]

OBJECTIVE

To study the expression of L-selectin, Mac-1, LFA-1 on CML progenitor cells in relation to CML progression and therapeutic effect.

METHODS

The expression of adhesion molecules (LFA-1, Mac-1, L-selectin) on bone marrow CD34+ cells from 34 CML patients were analyzed by three-color flow cytometry.

RESULTS

The mean percentage of expression of L-selectin, and LFA-1 on CD34+ CD38-(-)+ cells from untreated CML patients was significantly lower than that from normal controls. Among 8 CML patients treated with IFN-alpha, the expression of L-selectin and LFA-1 on CD34+ CD38- cell (37.6 +/- 5.3%, 42.1 +/- 13.1%) was comparable to that from normal controls (38.2 +/- 9.4%, 48.2 +/- 12.2%). L-selectin expression in CD34+ CD38- cells from CML patients was inversely correlated with the percentage of Ph'(+) cells. In 2 CML patients treated with allo-bone marrow transplantation, the expression rate of L-selectin, IFA-1 and Mac-1 on CD38+ CD38- cells was comparable to that from normal controls.

CONCLUSION

The data suggest that decreased expression of L-selectin and LFA-1 in CML CD34+ cells reflects one of the features of malignant CML progenitors. IFN-alpha and allo-BMT restore the expression of Mac-1, L-selectin and LFA-1 to normal on CML CD34+ cells.

Cleavage of ATM during radiation-induced apoptosis: caspase-3-like apoptotic protease as a candidate

PURPOSE

To study the relationship of ionizing radiation-induced apoptosis with the integrity of ATM (mutated in ataxia telangiectasia) that has a critical role in DNA damage sensing and repair, cell-cycle checkpoint controls and maintenance of genomic stability.

MATERIALS AND METHODS

U937 cells were treated with gamma-radiation. Sub-G1 DNA content, DNA fragmentation, cleavage of PARP, active caspase-3, cleavage of ATM in vivo and in vitro were measured by flow cytometry, agarose gel electrophoresis, cleaving of colorimetric caspase-3 substrate and Western blotting.

RESULTS

ATM is specifically cleaved in cells during the induction of apoptosis by ionizing radiation exposure. The time-course of cleavage coincided with the appearance of cells with a sub-G1 DNA content and activation of caspase-3. ATM was cleaved with similar kinetics as PARP and DEVD-FMK could abolish the cleavage. In vitro studies showed that ATM was cleaved by caspase-3 or related subfamily members at a DIVD/G site.

CONCLUSION

ATM belongs to a group of repair proteins, including PARP, DNA-PK and HsRad51, which are specifically cleaved during apoptosis. These findings support the idea that repair mechanisms need to be inactivated for apoptosis to proceed efficiently.

Treatment of childhood acute myelogenous leukemia with an intensive regimen (AML-87) that individualizes etoposide and cytarabine dosages: short- and long-term effects

The purpose of this study was to assess the feasibility and efficacy of a treatment regimen for pediatric acute myelogenous leukemia (AML) that uses four rotating drug pairs and adjusts dosages of etoposide and cytarabine to target specific plasma concentrations. Thirty-one girls and 27 boys (median age, 9.7 years) with de novo AML were treated on the protocol. Six cycles of chemotherapy were planned. Cycles 1 to 4 comprised the drug combinations cytarabine plus etoposide, cytarabine plus daunomycin, etoposide plus amsacrine, and etoposide plus azacitidine, respectively. For cycles 5 and 6, the first two combinations were repeated. Dosages were adjusted to achieve plasma concentrations of 1.0 microM +/- 0.1 microM cytarabine and 30 microM +/- 0.3 microM etoposide. Forty-four patients (76%) entered complete remission. Of those, 24 have had relapses; 23 remain alive in first or subsequent remission. The 5-year event-free survival (EFS) estimate was 31.0% +/- 5.9%; the 5-year survival estimate was 41.4% +/- 6.3%. Six patients (10%) died of the toxic effects of therapy. Severe neutropenia occurred in all cycles. Long-term complications of therapy included hepatitis C, cardiac insufficiency, and hearing loss. Adjustment of cytarabine and etoposide dosage was feasible for achieving targeted plasma drug concentrations; however, the potential clinical efficacy of this approach was offset by substantial acute and long-term toxicity.

Effects of zinc on creatine kinase: activity changes, conformational changes, and aggregation

The effects of zinc on creatine kinase (CK) are very distinctive compared with other bivalent metal ions. Zinc up to 0.1 mM induced increases in CK activity, accompanied by significant hydrophobic surface exposure and increase in alpha-helix content of CK. Zinc over 0.1 mM denatured and inactived CK. In the presence of 0.1 mM zinc, the CK activity was very close to that of the native CK, but its conformation changed greatly. The kinetic courses of CK inactivation and conformational change in the presence of 1 mM zinc were measured to determine apparent rate constants of inactivation and conformational change. Zinc over 0.05 mM induced CK aggregation at 37 degrees C, and the aggregation was dependent on zinc concentration, CK concentration, and temperature. The inactivation and aggregation can be reversed by EDTA. An explanation for CK aggregation induced by zinc is proposed, as well as a mechanism for CK abnormality in Alzheimer's disease.

Similar repopulating capacity of mitotically active and resting umbilical cord blood CD34(+) cells in NOD/SCID mice

It was hypothesized that during mammalian development, the extensive need for hematopoietic cells requires equal contribution to blood cell production from both quiescent and cycling hematopoietic stem cells (HSCs) while maintaining the stem cell pool. To investigate this hypothesis, the engraftment potential of umbilical cord blood (UCB) CD34(+) cells residing in either G(0) (G(0)CD34(+) cells) or G(1) (G(1)CD34(+) cells) phases of the cell cycle was assessed in nonobese diabetic/severe combined immune-deficient (NOD/SCID) mice. Whereas the level of chimerism in mice transplanted with UCB G(0)CD34(+) cells was 69.9% +/- 24.0%, mice receiving equal numbers of G(1)CD34(+) cells harbored 46.7% +/- 21.3% human cells 8 weeks posttransplantation. Both groups of cells sustained multilineage differentiation and the production of CD34(+) cells in recipient animals. The relationship between the number of transplanted G(0)CD34(+) or G(1)CD34(+) cells and the level of chimerism was analyzed by a general linear models procedure. Although the initial level of chimerism following transplantation of G(0)CD34(+) cells was higher than that sustained by G(1)CD34(+) cells, the increment in the degree of chimerism obtained with each additional 10(3) cells of either phenotype was identical, suggesting that the reconstitution potential of these 2 types of cells was similar. Of interest is that human cells recovered from primary recipients of both G(0)CD34(+) and G(1)CD34(+) cells engrafted in secondary NOD/SCID recipients, albeit at a substantially lower level, confirming the primitive nature of UCB CD34(+) cells residing in G(1).

Comparison of serum, cerebrospinal fluid and brain extracellular fluid pharmacokinetics of lamotrigine

We investigated the rate of penetration into and the intra-relationship between the serum, cerebrospinal fluid (CSF) and regional brain extracellular fluid (bECF) compartments following systemic administration of lamotrigine in rat. The serum pharmacokinetics were biphasic with an initial distribution phase, (half-life approximately 3 h), and then a prolonged elimination phase of over 30 h. The serum pharmacokinetics were linear over the range 10 - 40 mg kg(-1). Using direct sampling of CSF with concomitant serum sampling, the calculated penetration half-time into CSF was 0.42+/-0.15 h. At equilibrium, the CSF to total serum concentration ratio (0.61+/-0.02) was greater than the free to total serum concentration (0.39+/-0.01). Using in vivo recovery corrected microdialysis sampling in frontal cortex and hippocampus with concomitant serum sampling, the calculated penetration half-time of lamotrigine into bECF, 0.51+/-0.11 h, was similar to that for CSF and was not area or dose dependent. At equilibrium, the bECF to total serum concentration ratio (0.40+/-0.04) was similar to the free to total serum concentration (0.39+/-0.01), and did not differ between hippocampus and frontal cortex. The species specific serum kinetics can explain the prolonged action of lamotrigine in rat seizure models. Lamotrigine has a relatively slow penetration into both CSF and bECF compartments compared with antiepileptic drugs used in acute seizures. Furthermore, the free serum drug concentration is not the sole contributor to the CSF compartment, and the CSF concentration is an overestimate of the bECF concentration of lamotrigine.

Prognostic factors in infants with acute myeloid leukemia

Little is known about the factors that affect treatment outcome in very young children with acute myeloid leukemia (AML). We therefore analyzed the prognostic impact of various presenting clinical and laboratory features by discrete age group in 299 children with AML treated in four consecutive clinical trials between 1980 and 1997. Differences in presenting features, as well as treatment outcome, were compared between children aged 12 months or less (n = 28) or 13 to 24 months (n = 28) and those more than 24 months of age (n = 243). Children in the two youngest groups (24 months of age or less) had similar presenting features and treatment outcome. Collectively, these 56 children were significantly more likely than the 243 older patients to have M4 or M5 leukemia (70% vs 30%), CNS leukemia (33% vs 22%), the t(9;11) (p22;q23) (18% vs 6%) or other 11q23 translocations (23% vs 3%), and less likely to have Auer rods (2% vs 54%) or the t(8;21) (q22;q22) (0% vs 17%). Among patients aged 24 months or less, two factors independently predicted a favorable prognosis: FAB M4 or M5 leukemia (relative risk of relapse, 0.4; 95% confidence interval, 0.2-0.9) and the t(9;11) (relative risk, 0.3; 95% confidence interval, 0.1-1.0). Leukocyte count and 11q23 translocations other than the t(9;11) lacked prognostic significance. Among older patients, a leukocyte count <50 x 10(9)/l and the presence of the t(9;11) conferred a favorable prognosis.

Lipoxygenase-dependent mechanisms in hypertension

This study was designed to examine the contribution of lipoxygenase products to mechanisms of vascular contraction and elevated blood pressure in rats with aortic coarctation-induced hypertension. In cytosolic fractions of aortae taken from hypertensive rats, 12-lipoxygenase protein was increased as compared to normotensive controls. Aortic rings from hypertensive, but not from normotensive rats, exhibited a basal tone which was reduced 74+/-12 and 71+/-22%, respectively, by the lipoxygenase inhibitors cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate (CDC, 10(-5) mol/L) and 5,8,11-eicosatriynoic acid (ETI, 10(-5) mol/L). CDC (8 mg/kg s.c.) did not affect the blood pressure of normotensive rats but decreased that of hypertensive rats from 182+/-6 to 151+/-10 mm Hg. The blood pressure lowering effect of CDC was blunted in hypertensive rats pretreated with indomethacin or antibodies against 5,6-dihydro-prostaglandin I2. These data suggest contribution of lipoxygenase-derived products to mechanisms underlying aortic smooth muscle basal tone and elevated blood pressure in rats with aortic coarctation-induced hypertension. The vasodepressor effect of CDC depends on a mechanism involving vasodilatory prostaglandins.

Velocity and shape selection of dendritic crystals in a forced flow

The phase-field method is used to simulate the two-dimensional growth of a dendritic crystal in a forced flow. The selection of the velocity and shape of the dendrite tip is investigated as a function of flow rate, growth direction relative to the flow, as well as anisotropy strength, and the results for the upstream growing tips are compared to existing theoretical predictions.

[Colorectal cancer: lymphatic metastasis and choice of operation]

OBJECTIVE

To study lymphatic metastasis of colorectal cancer for deceding the of dissection extent of dissection.

METHODS

Six hundred and twenty-three lymph nodes from 74 cases of colorectal cancer were analyzed after D(3) resection. They were classified into peritumor, longitudinal spread, and upward spread groups. The metastasis rate of lymph node and its incidence were calculated.

RESULTS

The metastasis rate of lymph node and its incidence in the peritumor, longitudinal spread, and upward spread (N(2) and N(3)) groups were 47.2% and 38.6%, 22.8% and 18.6%, and 29.7% (20.3% and 9.4%) and 10.2% (19.0% and 5.3%), respectively. The distribution rate of metastatic lymph node was 61.2%, 17.1%, and 21.6% in the peritumor, longitudinal spread, and upward spread groups, respectively. Within 2.0 cm on the anal side of rectal cancer, the metastasis rate was 3.7%, whereas in 2.0 - 4.0 cm no metastasis was observed cancer at the lower part of the rectum demonstrated a higher lateral metastasis rate.

CONCLUSIONS

Colorectal cancer tends to metastasize to longitudinal and the risk of metastasis increased in the stage of pT(3) and pT(4) or low differentiation stage. Jump metastasis is also a feature. D(3) radical resection is necessary for colorectal cancer, but extended lateral lymph node needs enectomy or total mesorectal excision. No residual tumor tissue exists at the anastomosis site after low anterior resection when the excision distance is beyond 2.0 cm from the anal margin of rectal cancer.

Characterization of a technique for rapid pharmacokinetic studies of multiple co-eluting compounds by LC/MS/MS

A method for rapid pharmacokinetic screening of multiple potential drug candidates has been developed. This technique, based on the ability of liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) to independently monitor multiple components, enables the quantification of substances which may or may not be chromatographically resolved. Our results indicate that the limit of quantitation and accuracy of this multiple-compound LC/MS/MRM quantitation method are comparable to a single-compound LC/MS/MRM quantitation method. No apparent ion suppression due to the existence of extraneous compounds in the analytical solution and biological matrix effect are observed in the range of the calibration curve. The issue of potential residual molecule cross-talk interference existing in the multiple-reaction monitoring mode has been discussed. This multiple-compound LC/MS/MRM quantitation method can be used for high throughput pharmacokinetic screening and to assay mixtures that have co-eluting analytes or similar m/z of precursor/product ion pairs.

Assembly and structure of neurofilaments isolated from bovine spinal cord

Neurofilaments (NFs) are neuron-specific intermediate filaments. The NFs were isolated from bovine spinal cord by differential centrifugation. The NFs were detected with electron microscopy and scanning tunneling microscopy (STM). Under STM, two kinds of sidearm of NFs were revealed: one was short, the other was long. They were arrayed along the 10-nm width core filaments one by one. The intervals between two adjacent long sidearms or two short sidearms were 20-22 nm, while those between two adjacent long and short sidearms were 10-11 nm. It was proposed that the rod domain of NF triplet proteins was 3/4-staggered. The assembly properties of NF triplet proteins were also studied. Immuno-colloidal-gold labeling assay showed that NF-M and NF-H are able to co-assemble into long filaments with NF-L. NF-M and NF-H can also co-constitute into winding filaments.

[Study on tumor necrosis factor and pathogenesis of pregnancy induced hypertension]

OBJECTIVE

To study the role of tumor necrosis factor (TNF-alpha) in the pathogenesis of pregnancy induced hypertension (PIH).

METHODS

Radioimmunoassay was used to measure the levels of TNF-alpha in 25 severe PIH patients and 25 normal pregnant women. Umbilical vein endothelial cells were cultured with TNF-alpha (500 U/ml) or without TNF-alpha. The concentration of endothelin-1 (ET-1), 6-ket-PGF1 alpha, nitrite (NO2-), expression of fibronectin(FN) and white blood cells adhesion to the surface of endothelial cells test were measured.

RESULTS

The levels of TNF-alpha in serum of severe PIH patients were significantly higher than that of normal pregnant women (P < 0.05). In endothelium culture supernatant with TNF-alpha group, synthesis of ET-1, NO2- and 6-ket-PGF1 alpha increased, expression of FN on the surface of endothelial cells decreased, white blood cells adhesion to endothelial cells increased. There was significant difference between TNF-alpha group and control group.

CONCLUSION

TNF-alpha may be involved in the pathogenesis of PIH.

Contribution of endogenous carbon monoxide to regulation of diameter in resistance vessels

Endogenous carbon monoxide was proposed to subserve vasodepressor functions. If so, inhibition of heme oxygenase may be expected to promote vascular contraction. This hypothesis was examined in large and small arteries and in isolated first-order gracilis muscle arterioles of rat. The heme oxygenase inhibitors chromium mesoporphyrin (CrMP) and cobalt protoporphyrin (0.175-102 micromol/l) decreased the diameter of pressurized (80 mmHg) gracilis muscle arterioles, whereas magnesium protoporphyrin, a weak heme oxygenase inhibitor, did not. CrMP also elicited development of isometric tension in the muscular branch of the femoral artery but not in the aorta or femoral artery. Arteriolar constrictor responses to CrMP varied in relation to the intravascular pressure, were blunted in preparations exposed to exogenous carbon monoxide (100 micromol/l), and were unaffected by an endothelin receptor antagonist. Importantly, CrMP amplified the constrictor response to increases of pressure in gracilis arterioles. Accordingly, the constrictor effect of heme oxygenase inhibitors is attributable to magnification of myogenic tone due to withdrawal of a vasodilatory mechanism mediated by endogenous carbon monoxide. The study suggests that the vascular carbon monoxide system plays a role in the regulation of basal tone in resistance vessels.

[Study of autoimmunity in progeny of pregnant women with systemic lupus erythematosus]

OBJECTIVE

To study the effect of systemic lupus erythematosus (SLE) on physical, mental development and plasma antibody level of SLE in their progenies.

METHODS

Routine physical examinations of 49 children from 48 SLE mothers were conducted. Compared immuno-fluorescence anti-nuclear antibody (IFANA), anticardiolipin (ACL), extractable nuclear antigen (ENA) and anti-ds-DNA plasma levels of SLE mothers and their progenies with that levels during pregnancy and in umbilical blood.

RESULTS

The physical development (height and weight) in 47 out of 49 children were within normal range while the remaining 2 were in the lower limit. The autoimmune antibodies were all negative in the umbilical blood with autoimmune negative mothers, while the anti-ribonucleoprotein (anti-RNP), anti-Smith surface antigen (anti-SSA), anti-specific soluble ribonucleic acid (anti-SSB) and ACL could be transferred to fetus through placenta. During follow up study, compared the autoimmune positive rates in progenies with that of mothers, the positive rates of IFANA and anti-ds-DNA decreased significantly (P < 0.01), while no changes in ACL. Compared the autoimmune positive rates in progenies with that of their own umbilical levels, the positive rates of IFANA, anti-RNP, anti-SSA decreased significantly (P < 0.01), while no difference existed in ACL. Boys showed faster disappearance of autoimmune positive rates than that of girls.

CONCLUSIONS

SLE did not show significant effects on the physical development of their progenies. Most autoimmune antibodies existed in umbilical blood were transferred through placenta during pregnancy and would disappear within 9 years after birth. Autoimmune antibodies decreased quicker in boys, and it indicated that girls should be follow-up more carefully. Autoimmune antibodies in the umbilical blood is an easy method for the screening of SLE progeny.

[Serum concentration of interleukin-6 in maternal serum and its expression in amniochorionic membranes of preterm premature rupture of membrane]

OBJECTIVE

To investigate the relationship between interleukin-6 (IL-6) and preterm premature rupture of membranes (PPROM).

METHODS

Serum IL-6 in 20 cases of normal pregnancy (control group) and 30 cases with PPROM in which 14 had moderate and severe chorioamnionitis (group 1), 16 had no chorioamnionitis (group 2) were measured by enzyme-linked immunosorbent assay (ELISA), and IL-6 protein in fetal membranes were determined by immunohistochemistry technique.

RESULTS

The level of serum IL-6 in group 1 (155.17 ng/L) was significantly higher than that in group 2 (79.11 ng/L) and control group (70.15 ng/L) (P < 0.01). Expression of the IL-6 had more positive signs in chorion with chorioamnionitis, especially in infiltrating inflammatory cells.

CONCLUSION

IL-6 associated with the onset of preterm labor caused by infection.

[Studies on the supercritical-CO2 fluid extraction and quality evaluation of ginger oils]

Essential oils from the dried rhizomes of Zingiber officinale were extracted by supercritical-CO2 fluid(SFE-CO2) and traditional water still distillation (WSD) methods, and the SFE extraction technology and quality (GC-MS, etc.) of the oils were studied. The results showed that the SFE-CO2 contains 49 constituents, such as 6-paradol, etc, the ginger peppery component of them gets to 22.90%.

Comparison of long-term survival of cytomegalovirus promotre versus Rous Sarcoma virus promoter-driven thymidine kinase gene therapy in nude mice bearing human ovarian cancer

The cytomegalovirus (CMV) promoter is considered one of the strongest positive regulators leading to expression of higher levels of the thymidine kinase (TK) enzyme than the Rous Sarcoma virus (RSV) promoter in vitro and in vivo. Cell killing efficacy of adenovirus-mediated CMV promoter-driven herpes simplex virus (HSV) TK gene therapy has been found to be 2 to 10 times more effective than RSV driven HSV-TK gene therapy in vitro. In this study the impact of CMV- versus RSV-driven HSV-TK gene therapy on long-term survival of nude mice bearing human ovarian cancer has been evaluated using a prospective randomized experimental design. The experiment was designed to show significance of survival differences from a 50% increase of survived days at a p-value of 0.05 with a power of 80%. All treatment groups showed an increase in median survival compared with control groups. Treatment benefit was ADV/CMV-TK vector dose dependent. At a given viral dose, no significant prolongation of survival was observed comparing CMV- and RSV-driven ADV-TK indicating that simply increasing cell killing efficacy in vitro above a minimal threshold level using a stronger promoter may not lead to prolongation of survival in the HSV-TK/GCV system.

[A dynamic study of influences of TMJOA on TMJ disc]

OBJECTIVE

To learn the changes of TMJ disc positions under the influences of TMJ Osteoarthrosis(TMJOA).

METHODS

The TMJOA experimental animal model was established by 12 goats. The TMJ disc positions were observed and recorded at different intervals, (1 month, 2 months, 3 months, 4 months and 6 months) then the pathological changes of TMJ specimens were also studied.

RESULTS

Significant anteromedial shift of TMJ disc position was observed in some certain TMJOA phases and became more obviously along with the disease progress.

CONCLUSION

The shift of TMJ disc may be the secondary change of TMJOA.

Computer simulation of particle separation based on non-equilibrium swelling

Steric/hyperlayer field-flow fractionation (FFF) is an established analytical technique for separating and characterizing particles in the 1-100 microns diameter range. The separation can be based on differences in size, density, shape and mechanical properties of the particles. In the course of an analysis of the water transporter system of Chinese hamster ovary (CHO) cells and one of their high permeability mutants, the first successful attempt was made to use the steric/hyperlayer FFF system for the purpose of separating particles based on a time-dependent property, namely, the differential swelling of the two cell types. The present study was undertaken to simulate numerically the separation and suggest selection of operating conditions to minimize repetitive experiments. The computer simulation was developed using Maple V, a symbolic computing environment. It is shown that the model is able to predict an optimal velocity of carrier buffer that maximizes resolution. Predicted velocity/resolution pairs are in good agreement with available experimental data. Empirical models for the lift forces encountered in such FFF experiments, and for the zone broadening observed in work with cell sized particles, form the basis for this model.

[Expression of endothelin-1 and endothelin-1 mRNA in placental villus of pregnancy induced hypertension and the changes of plasma endothelin-1]

OBJECTIVE

To investigate the role of endothelin (ET-1) in the pathogenesis of pregnancy induced hypertension (PIH).

METHODS

In 70 cases of PIH the plasma concentration of ET-1 was measured by RIA, and the expressions of ET-1 and its mRNA in placental villus were determined by immunohistochemistry and in situ hybridization respectively. 30 normal pregnant women (NP) served as control group.

RESULTS

(1) The Plasma concentration of ET-1 was significantly higher in PIH than that in NP. There was a positive correlation between the plasma ET-1 level and mean arterial pressure in PIH. (2) The expressions of ET-1 and ET-1 mRNA were found in syncytiotrophoblast of placental villus and in the endothelium of fetal vessels. These positive signals were higher in PIH than in NP.

CONCLUSION

The injury of endothelium of fetal and placental blood vessels was one of the causes of PIH. The placenta may play an important role in the pathogenesis of PIH.

Adenovirus mediated thymidine kinase gene therapy may enhance sensitivity of ovarian cancer cells to chemotherapeutic agents

The current treatment concept of ovarian cancer consists of radical surgery with subsequent chemotherapy. We have shown that adenovirus (ADV) mediated thymidine kinase (TK) gene transduction of cisplatin-resistant human ovarian cancer xenotransplanted into nude mice followed by ganciclovir (GCV) administration leads to prolongation of survival or cure. In this study the interaction of ADV-TK gene therapy and selected chemotherapeutic agents commonly used for the treatment of ovarian cancer was investigated in three ovarian cancer cell lines with different growth patterns. Toxicity and cell killing efficacy of gene therapy, chemotherapy and their combinations with different concentrations and time intervals were measured by a 3-(4,5- dimethylthiazol)-2,5-diphenyl tetrazolium bromide (MTT) based assay. A slightly increased resistance to gene therapy was observed in cells pretreated with chemotherapy. Removal of the drugs restored the previous susceptibility of the cells to gene therapy. No antagonism was observed with gene therapy followed by chemotherapy. The concomitant application of gene therapy and chemotherapy resulted in a higher rate of cell death than the interval therapy. A dose dependent synergistic interaction was observed only for the combination of gene therapy and the topoisomerase 1 inhibitor topotecan. This synergistic effect was still seen even if the chemotherapeutic agent was added 72 hours later. Our data demonstrate that in addition to its own therapeutic efficacy, ADV-TK based gene therapy may enhance the effect of subsequent chemotherapy while up-front chemotherapy was disadvantageous.

[Expression of endothelial nitric oxide synthase gene in placental villus of preeclampsia]

OBJECTIVE

To investigate the expression of endothelia nitric oxide synthase (eNOS) mRNA in the villus of preeclampsia and the relationship between eNOS and preeclampsia.

METHODS

Dot blot, using DIG-labeled human eNOS cDNA probe, had been used to examine the expression of eNOS gene in placental tissues of 9 normotensive pregnancy and 9 preeclampsia women. By using Leica QWIN image disposal and analysis system Mean OD of every dot was assessed.

RESULTS

The level of eNOS mRNA in placental villus was significantly lower in preeclampsia woman than that of control group (P < 0.001).

CONCLUSION

The decrease of eNOS in placental villus of preeclampsia may be one of the causes for human placental dysfunction and high impedance of fetoplacental circulation in preeclampsia. It may play an improtant role in the genesis of pregnancy induced hypertension.

[Applied anatomy of the temporal and frontal regions in endoscopic temporal lifting]

OBJECTIVE

This anatomic study was carried out in a bid to decrease damage of the temporal branch of the face nerve in endoscopic temporal lifting.

METHODS

We dissected the frontal-temporal region and located the temporal branch on 36 sides of adult head specimens.

RESULTS

It was found that the temporal branch is deep to the temporoparietal fascia and frontal muscle. The temporal branch has one to four branches in general. The first one is 8.1 +/- 2.1 mm anterior to articular tubercle and 33.8 +/- 4.9 mm superior to the bony lateral canthus. The temporal branches locate below a line drawn from the articular tubercle to 40 mm above the bony lateral canthus.

CONCLUSION

It is suggested that the operation incisions in the temporal region be selected above this line.

Total glycolipid and glucosylceramide content in serum and urine of patients with Gaucher's disease type 3 before and after enzyme replacement therapy

The follow-up of Gaucher's patients under enzyme replacement therapy is generally based both on the clinical aspects and the evaluation of haematological parameters: haemoglobin level, platelet count, acid and alkaline phosphatase activities. Spleen and liver volumes are also reliable criteria for evaluating the improvement of the patients. The determination of glycolipid excretion in the urine and/or the quantification of glycolipids in serum can also be a useful tool for the screening and the follow up of patients with lysosomal storage disease including Gaucher's disease. In this paper we report the follow-up of three patients with Gaucher type 3; in order to test the efficacy of the enzyme replacement therapy with alglucerase in these patients, we evaluated the urine and plasma glucosylceramide content as a marker parallel to the clinical improvement and the decreased organomegaly.

Comparison of single- and repeated-dose pharmacokinetics of diazepam

PURPOSE

To determine whether repeat boluses of diazepam (DZP) lead to significant accumulation in the central nervous system and/or peripheral compartments, as repeat intravenous boluses of diazepam are commonly used in the treatment of status epilepticus (SE).

METHODS

In a rat model that permits simultaneous serum and cerebrospinal fluid (CSF) sampling, we characterized the pharmacokinetics of DZP and its metabolite, desmethyldiazepam, in CSF and blood using HPLC. DZP was administered by intraperitoneal injection as either a single dose (20 or 30 mg/kg) or repeat doses (10 or 20 mg/kg x 3, 1 h apart).

RESULTS

After a single intraperitoneal dose, DZP was rapidly absorbed with a time to maximum concentration of 10 min. The serum concentrations then declined biexponentially. DZP rapidly entered the CSF, the CSF to serum ratio reached equilibrium within 10 min, and was equivalent to the ratio of free to total serum concentration. Repeated DZP dosing resulted in a threefold decrease in volume of distribution and clearance (p < 0.001). This was reflected in the CSF concentration data; however, after the third dose, the ratio of CSF to serum concentration, also increased greatly, representing further persistence of DZP in the CSF compartment.

CONCLUSIONS

Repeat dosing of DZP leads to substantial accumulation, and high, persistent serum and CSF concentrations, which may explain the toxic effects of repeat DZP dosing. Repeat dosing of DZP using a tapering protocol, however, may increase the effectiveness of DZP in treating SE by preventing relapses without substantially increasing toxicity.

The efficacy of adenovirus-mediated gene therapy of ovarian cancer is enhanced by using the cytomegalovirus promoter

The cytomegalovirus(CMV) promoter is considered one of the strongest positive regulators. In this study toxicity, cell killing efficacy and bystander effect of Rous Sarcoma Virus(RSV) driven herpes simplex thymidine kinase(TK) gene therapy was compared with CMV driven TK gene therapy in three ovarian cancer cell lines with different growth patterns using a 3-(4,5-dimethylthiazol)-2,5-diphenyl tetra-zolium bromide (MTT) based assay. ADV/CMV-TK was shown to be 2 to 10 times more effective in tumor cell killing than ADV/RSV-TK. The difference in cell killing efficacy between ADV/CMV-TK and ADV/RSV-TK was dependent on the individual cell line. A CMV promoter dependent eight to ten fold improvement in cell killing efficacy was observed in the relatively slow growing SKOV3 cell line which is not easily transducible, while only a 2 to 4 fold difference was observed in the easily transducible OV-CA-2774 and OV-CA-1225 cell lines. ADV/CMV-TK also showed a stronger bystander effect than ADV/RSV-TK in all three ovarian cancer cell lines. Our data demonstrated that the efficacy of adenovirus-mediated gene therapy of ovarian cancer can be enhanced by using the CMV promoter without increasing toxicity.

Interaction of the bovine papillomavirus E6 protein with the clathrin adaptor complex AP-1

The E6 gene of the bovine papillomavirus type 1 (BPV-1) is expressed in fibropapillomas caused by BPV-1 and in tissue culture cells transformed by BPV-1. It encodes one of the two major oncoproteins of BPV-1. In this study, we demonstrate an interaction between the BPV-1 E6 protein and AP-1, the TGN (trans-Golgi network)-specific clathrin adaptor complex. AP-1 is a four-subunit protein complex required for clathrin-mediated cellular transport from the TGN. The AP-1/E6 interaction was observed in vitro and in cells. The E6 binding site on AP-1 was mapped to the N-terminal trunk domain of the gamma subunit. BPV-1 E6 preferentially associated with membrane-bound AP-1 in cells but not with free cytosolic AP-1. BPV-1 E6 was further shown to be recruited to isolated Golgi membranes and to copurify with clathrin-coated vesicles. The recruitment of BPV-1 E6 to Golgi membranes was AP-1 independent, but the E6 interaction with AP-1 was required for its association with clathrin-coated vesicles. Furthermore, AP-1 proteins could compete with BPV-1 E6 for binding to Golgi membranes, suggesting that the recruitment of BPV-1 E6 and AP-1 to Golgi membranes involves a common factor. Taken together, our results suggest that cytosolic BPV-1 E6 is first recruited to the TGN, where it is then recognized by membrane-bound AP-1 and subsequently recruited into TGN-derived clathrin-coated vesicles. We propose that BPV-1 E6, through its interaction with AP-1, can affect cellular processes involving clathrin-mediated trafficking pathway.

The bovine papillomavirus E6 protein binds to the LD motif repeats of paxillin and blocks its interaction with vinculin and the focal adhesion kinase

The bovine papillomavirus type 1 (BPV-1) E6 oncoprotein can transform fibroblasts and induce anchorage-independent growth and disassembly of the actin stress fibers. We have previously shown that the E6 protein interacts with the focal adhesion protein, paxillin, suggesting a direct role of E6 in the disruption of the actin cytoskeleton. We have now mapped the E6 binding sites on paxillin to the LD motif repeats region, which has been implicated in mediating paxillin binding to two other focal adhesion proteins, vinculin and the focal adhesion kinase. The five LD motif repeats identified in paxillin do not contribute equally to its interaction with E6. The first LD repeat is most critical for paxillin binding to E6 both in vitro and in vivo. Furthermore, the binding of recombinant wild-type E6 protein to paxillin blocked the interaction of several cellular proteins with paxillin, including vinculin and the focal adhesion kinase. A mutant E6 protein (H105) which does not bind to paxillin had no effect on the binding of these cellular proteins to paxillin. These data suggest that E6 disruption of the actin stress fibers occurs through blocking the interaction of paxillin with its cellular effectors such as vinculin and the focal adhesion kinase.

[Animal experiment on gene therapy of ovarian cancer by adenovirus-mediated thymidine kinase gene transduction and ganciclovir administration in vivo]

OBJECTIVE

The efficacy and toxicity of adenovirus-mediated transduction of herpes simplex virus thymidine kinase gene started by Rous sarcoma virus (ADV/RSV-tk) followed by administration of ganciclovir (GCV) were studied in vivo.

METHODS

An animal model of human epithelial ovarian cancer was established in nude mice using the serous ovarian adenocarcinoma cell lines Ov-ca-2774, then mice were treated by ADV/RSV-Tk and GCV, or GCV and HSV-tk respectively. The average survival time of mice and toxicity were assessed.

RESULTS

The mice treated with GCV or HSV tk alone died from 14.4 +/- 1.7 to 19.3 +/- 3.5 days after treatment. The survival time had no difference with control group. The mice treated with ADV/RSV-tk followed by GCV lived at least two times longer than controls and the difference in both groups was significant. The earlier the treatment began, the longer the average survival time was. Treatment efficacy was dependent on dose of ADV/RSV-tk and tumor burden of mice.

CONCLUSION

ADV/RSV-tk gene therapy is a safe and efficient approach to ovarian cancer treatment in the experiment.

Dynamic 13C NMR analysis of pyruvate and lactate oxidation in the in vivo canine myocardium: evidence of reduced utilization with increased work

In this work, substrate selection was monitored in the left ventricle of the canine myocardium by following pyruvate and lactate oxidation under in vivo conditions at basal and elevated workloads. These studies were conducted in the open chest model using dynamic 13C NMR techniques in the presence and absence of dichloroacetic acid (DCA), a well-known activator of pyruvate dehydrogenase (PDH). Following the infusion of (3-(13)C) pyruvate or (3-(13)C) lactate into the left anterior descending artery, highly variable 13C enrichments of glutamate, alanine, aspartate, and citrate were noted under low (RPP < 14,500 mmHg/min), intermediate (RPP = 15,000-25,000 mmHg/min), and high (RPP > 25,500 mmHg/min) rate pressure products (RPP). At low workloads, the myocardium typically oxidized the infused (3-(13)C) pyruvate or (3-(13)C) lactate and incorporated the labeled carbon into the glutamate pool as expected. However, in a few notable instances (n = 3), 13C-enriched pyruvate and lactate were unable to label the glutamate pool under in vivo conditions even at the lowest RPPs, indicating a lack of selection for these substrates by the tricarboxylic acid (TCA) cycle. Nonetheless, the levels of glutamate C4 enrichment observed at low workloads could usually be enhanced by infusion of DCA. Importantly, 13C NMR extract analysis revealed that (3-(13)C) pyruvate or (3-(13)C) lactate labeling of the glutamate pool was reduced (< 20%) at high workloads in spite of increased DCA concentrations.

A GFP reporter system to assess gene transfer and expression in human hematopoietic progenitor cells

Hematopoietic stem cells are widely recognized as attractive targets for gene therapy but current protocols to transduce these cells using recombinant retroviral vectors are inefficient. To evaluate optimization of retroviral transduction of hematopoietic stem cells and stability of gene expression in their progeny, the green fluorescent protein (GFP) was explored as a reporter. We first improved sensitivity of detection > 100-fold over that achieved previously by using a novel retroviral vector (termed MGIN) expressing a high level of an enhanced GFP gene. Primitive human hematopoietic cells bearing the CD34 surface antigen and lacking lineage differentiation markers (CD34+ Lin-) were transduced with the MGIN vector using a clinically applicable supernatant procedure. Under the conditions employed, > 75% of the target cells retained the CD34+ Lin- primitive phenotype after 4-5 days in culture, of those > or = 25% expressed a high level of GFP detectable by both flow cytometric analysis and fluorescence microscopy. When transduced cells were cultured in clonogenic progenitor assays, GFP fluorescence was readily detected in situ, indicating that GFP expression was stable and not detrimental to the differentiative potential of the transduced CD34+ Lin- cells. We conclude that GFP is effective as a vital marker to quantity retrovirus-mediated gene transfer into human hematopoietic and perhaps other types of stem/progenitor cells, and monitor gene expression during their subsequent cell lineage determinations.