[Improvement of combination chemotherapy tolerance of human umbilical cord blood CD(34)(+) cells transducted with double drug resistance genes by a bicistronic retroviral vector]

OBJECTIVE

To explore whether human umbilical cord blood hematopoietic progenitor cells transduced with human aldehyde dehydrogenase class 3 (ALDH3) and multidrug resistance gene (MDR1) could increase resistance to 4-hydroxycyclophosphamide (4-HC) and P-glycoprotein effluxed drugs.

METHODS

A bicistronic retroviral vector G1Na-ALDH3-IRES-MDR1 cDNA was constructed and transfected the packaging cell lines GP + E86 and PA317 by LipofectAMINE method, using the medium containing VCR and 4-HC for cloning selection and ping-ponging supernatant infection between ecotropic producer clone and amphotropic producer clone, cord blood CD(34)(+) cells were enriched with a high-gradient magnetic cell sorting system (MACS), and then repeatedly transfected with supernatant of retrovirus containing human ALDH3 and MDR1 cDNA under stimulation of hematopoietic growth factors. PCR, RT-PCR, Southern blot, Northern blot, FACS and MTT assay were used to evaluate the transfection and expression of the double genes.

RESULTS

The purity of cord blood CD(34)(+) cells was approximately 91% and the recovery rate was 72%. The highest titer of recombinant amphotropic retrovirus in the supernatant was up to 6.5 x 10(5) CFU/ml. The efficiency of gene transduction was 18%, 20% and 16.7% tested by colony formation, PCR and FACS, respectively. Rhodamine 123 efflux showed 16% transduced cells with P-gp function. No helper virus was found by both nested PCR and rescue assay. The MTT analysis showed a 3.5 to 6.8-fold increase of resistance of transducted cells to cyclophosphamide and P-glycoprotein effluxes drug as compared with the nontransduced cells.

CONCLUSION

The efficiency and co-expression of this dual genes transfer system provided a foundation for ameliorating combination chemotherapy toxicity in clinical trial.

Intracranial bone marrow transplantation after traumatic brain injury improving functional outcome in adult rats

OBJECT

The authors tested the hypothesis that intracranial bone marrow (BM) transplantation after traumatic brain injury (TBI) in rats provides therapeutic benefit.

METHODS

Sixty-six adult Wistar rats, weighing 275 to 350 g each, were used for the experiment. Bone marrow prelabeled with bromodeoxyuridine (BrdU) was harvested from tibias and femurs of healthy adult rats. Other animals were subjected to controlled cortical impact, and BM was injected adjacent to the contusion 24 hours after the impact. The animals were killed at 4, 7, 14, or 28 days after transplantation. Motor function was evaluated both before and after the injury by using the rotarod test. After the animals had been killed, brain sections were examined using hemotoxylin and eosin and immunohistochemical staining methods. Histological examination revealed that, after transplantation, BM cells survived, proliferated, and migrated toward the injury site. Some of the BrdU-labeled BM cells were reactive, with astrocytic (glial fibrillary acid protein) and neuronal (NeuN and microtubule-associated protein) markers. Transplanted BM expressed proteins phenotypical of intrinsic brain cells, that is, neurons and astrocytes. A statistically significant improvement in motor function in rats that underwent BM transplantation, compared with control rats, was detected at 14 and 28 days posttransplantation.

CONCLUSIONS

On the basis of their findings, the authors assert that BM transplantation improves neurological outcome and that BM cells survive and express nerve cell proteins after TBI.

Therapeutic benefit of intravenous administration of bone marrow stromal cells after cerebral ischemia in rats

BACKGROUND AND PURPOSE

We tested the hypothesis that intravenous infusion of bone marrow derived-marrow stromal cells (MSCs) enter the brain and reduce neurological functional deficits after stroke in rats.

METHODS

Rats (n=32) were subjected to 2 hours of middle cerebral artery occlusion (MCAO). Test groups consisted of MCAO alone (group 1, n=6); intravenous infusion of 1x10(6) MSCs at 24 hours after MCAO (group 2, n=6); or infusion of 3x10(6) MSCs (group 3, n=7). Rats in groups 1 to 3 were euthanized at 14 days after MCAO. Group 4 consisted of MCAO alone (n=6) and group 5, intravenous infusion of 3x10(6) MSCs at 7 days after MCAO (n=7). Rats in groups 4 and 5 were euthanized at 35 days after MCAO. For cellular identification, MSCs were prelabeled with bromodeoxyuridine. Behavioral tests (rotarod, adhesive-removal, and modified Neurological Severity Score [NSS]) were performed before and at 1, 7, 14, 21, 28, and 35 days after MCAO. Immunohistochemistry was used to identify MSCs or cells derived from MSCs in brain and other organs. RESULTS Significant recovery of somatosensory behavior and Neurological Severity Score (P<0.05) were found in animals infused with 3x10(6) MSCs at 1 day or 7 days compared with control animals. MSCs survive and are localized to the ipsilateral ischemic hemisphere, and a few cells express protein marker phenotypic neural cells.

CONCLUSIONS

MSCs delivered to ischemic brain tissue through an intravenous route provide therapeutic benefit after stroke. MSCs may provide a powerful autoplastic therapy for stroke.

Primary follicular large cell lymphoma of the testis in a child

Primary follicular lymphoma of the testis in childhood is extremely rare. To our knowledge, only 5 cases have been reported to date. We report a case in a 6-year-old boy who presented with painless right scrotal enlargement. Right radical orchiectomy revealed a follicular large cell lymphoma with diffuse areas confined to the testis and epididymis, clinical stage IE. Immunohistochemical stains demonstrated that the neoplastic cells were of B-cell lineage, positive for CD10, CD20, CD79a, and BCL-6. Staining for CD21 accentuated networks of dendritic reticulum cells within the nodules. The cells were negative for BCL-2, p53, and T-cell antigens. There was no evidence of the t(14;18) detected by polymerase chain reaction. The data suggest that follicular lymphoma of the testis in children has a different pathogenesis than follicular lymphoma in adults.

Route of simian immunodeficiency virus inoculation determines the complexity but not the identity of viral variant populations that infect rhesus macaques

A better understanding of the host and viral factors associated with human immunodeficiency virus (HIV) transmission is essential to developing effective strategies to curb the global HIV epidemic. Here we used the rhesus macaque-simian immunodeficiency virus (SIV) animal model of HIV infection to study the range of viral genotypes that are transmitted by different routes of inoculation and by different types of viral inocula. Analysis of transmitted variants was undertaken in outbred rhesus macaques inoculated intravenously (IV) or intravaginally (IVAG) with a genetically heterogeneous SIVmac251 stock derived from a well-characterized rhesus macaque viral isolate. In addition, we performed serial IV and IVAG passage experiments using plasma from SIV-infected macaques as the inoculum. We analyzed the V1-V2 region of the SIV envelope gene from virion-associated RNA in plasma from infected animals by the heteroduplex mobility assay (HMA) and by DNA sequence analysis. We found that a more diverse population of SIV genetic variants was present in the earliest virus-positive plasma samples from all five IV SIVmac251-inoculated monkeys and from two of five IVAG SIVmac251-inoculated monkeys. In contrast, we found a relatively homogeneous population of SIV envelope variants in three of five monkeys inoculated IVAG with SIVmac251 stock and in two monkeys infected after IVAG inoculation with plasma from an SIV-infected animal. In some IVAG-inoculated animals, the transmitted SIV variant was the most common variant in the inoculum. However, a specific viral variant in the SIVmac251 stock was not consistently transmitted by IVAG inoculation. Thus, it is likely that host factors or stochastic processes determine the specific viral variants that infect an animal after IVAG SIV exposure. In addition, our results clearly demonstrate that the route of inoculation is associated with the extent and breadth of the genetic complexity of the viral variant population in the earliest stages of systemic infection.

Adult bone marrow stromal cells administered intravenously to rats after traumatic brain injury migrate into brain and improve neurological outcome

To measure effect of bone marrow stromal cells (MSCs) administered i.v. on rats subjected to traumatic brain injury (TBI), we injected MSCs labeled by BrdU into the tail vein 24 h after TBI and sacrificed rats 15 days later. The neurological severity score (NSS) and the Rotarod test were used to evaluate neurological function. The distribution of the donor cells in brain, heart, lung, kidney, liver and spleen were analyzed in recipient rats using immunohistochemical staining. MSCs injected i.v. significantly reduced motor and neurological deficits compared with control groups by day 15 after TBI. The cells preferentially entered and migrated into the parenchyma of the injured brain and expressed the neuronal marker NeuN and the astrocytic marker GFAP. MSCs were also found in other organs and primarily localized to the vascular structures, without any obvious adverse effects. Our data suggest that i.v. administration of MSCs may be useful in the treatment of TBI.

Overexpression of a modified human malonyl-CoA decarboxylase blocks the glucose-induced increase in malonyl-CoA level but has no impact on insulin secretion in INS-1-derived (832/13) beta-cells

The long-chain acyl-CoA (LC-CoA) model of glucose-stimulated insulin secretion (GSIS) holds that secretion is linked to a glucose-induced increase in malonyl-CoA level and accumulation of LC-CoA in the cytosol. We have previously tested the validity of this proposal by overexpressing goose malonyl-CoA decarboxylase (MCD) in INS-1 cells, but these studies have been criticized due to: 1) the small insulin secretion response (2-4-fold) of the INS-1 cells used; 2) unknown contribution of the ATP-sensitive K(+) (K(ATP)) channel-independent pathway of GSIS in INS-1 cells, which has been implicated as the site at which lipids regulate insulin granule exocytosis; and 3) deletion of the N-terminal mitochondrial targeting sequence, but not the C-terminal peroxisomal targeting sequence in the goose MCD construct, raising the possibility that a significant fraction of the overexpressed enzyme was localized to peroxisomes. To address these outstanding concerns, INS-1-derived 832/13 cells, which exhibit robust K(ATP) channel-dependent and -independent pathways of GSIS, were treated with a new adenovirus encoding human MCD lacking both its mitochondrial and peroxisomal targeting sequences (AdCMV-MCD Delta 5), resulting in large increases in cytosolic MCD activity. Treatment of 832/13 cells with AdCMV-MCD Delta 5 completely blocked the glucose-induced rise in malonyl-CoA and attenuated the inhibitory effect of glucose on fatty acid oxidation. However, MCD overexpression had no effect on K(ATP) channel-dependent or -independent GSIS in 832/13 cells. Furthermore, combined treatment of 832/13 cells with AdCMV-MCD Delta 5 and triacsin C, an inhibitor of long chain acyl-CoA synthetase that reduces LC-CoA levels, did not impair GSIS. These findings extend our previous observations and are not consistent with the LC-CoA hypothesis as originally set forth.

The T-cell chemokine receptor CXCR3 is expressed highly in low-grade mycosis fungoides

Three chemokines, Mig, IP-10, and I-TAC, are expressed highly in the epidermis. We examined the expression of the receptor for these chemokines, CXCR3, in cutaneous T-cell lymphoma. We compared CXCR3 expression with that of cutaneous lymphocyte antigen (CLA) and the activation marker CD30. CXCR3 was expressed by at least a subset of tumor lymphocytes in all 25 cases of low-grade mycosis fungoides (MF), with most cells positive in 20 cases. In progressed or transformed MF, CXCR3 expression was noted in 5 of 22 cases. In 4 of 5 MF cases with sequential biopsy specimens, large cell transformation was accompanied by loss of CXCR3 expression. In contrast, CLA was expressed in 35 of 42 MF cases with no significant differences in expression level between low-grade and transformed cases. In other lymphomas, CXCR3 was expressed in 4 of 4 cases of lymphomatoid papulosis, 3 of 4 cases of CD8+ cutaneous T-cell lymphoma, and 3 of 6 cases of systemic T-cell lymphoma in skin, but not in 10 cases of cutaneous anaplastic large cell lymphoma. CXCR3 expression was associated with epidermotropic T-cell tumors but was largely absent in dermal-based tumors. This phenotypic change likely influences the loss of epidermal localization.

[Single nucleotide polymorphism in beta2-adrenoceptor gene and the distribution in Chinese Han ethnic group]

OBJECTIVE

The study was conducted to investigate single nucleotide polymorphism(SNP) in beta2-adrenoceptor(beta2-AR) gene and the distribution of these identified SNPs in Chinese Han ethnic group.

METHODS

beta2-AR gene was sequenced to detect SNPs by fluorescent labeling automatic sequencing method in 80 unrelated samples from territory of Dabie Mountain in Anhui province.

RESULTS

A total of 8 SNPs were identified in length of 3.8 kb, including 5 SNPs in code region, 3 SNPs in regulatory region. Although the variations, -468C to G, -367T to C, -47C to T,-20T to C, +79C to G, +100G to A, +491C to T, +1098T to C have been identified in other ethnic groups, they have not been found in our study. The allele distribution of SNPs is in good unity with the Hardy-Weinberg equilibrium.

CONCLUSION

The distribution of SNPs in beta2-AR gene is not equable and the SNPs in different ethnic groups differ greatly. The allele distribution of SNPs conforms well to the Hardy-Weinberg equilibrium.

[Relationship between soluble Fas ligand levels and complications after allogeneic bone marrow transplantation]

OBJECTIVE

To evaluate the implications of soluble Fas ligand (sFasL) in acute graft-versus-host disease (aGVHD) and discriminating symptoms of aGVHD from those of infection.

METHODS

Plasma levels of sFasL were assessed in 84 plasma samples from 13 patients after allogeneic BMT using a sandwich enzyme-linked immunological assay (ELISA). Plasma sFasL levels of the patients before BMT and at different time points in the post-BMT period were measured. The results were analysed for correlation with aGVHD and infections.

RESULTS

Plasma sFasL levels were significantly higher in patients with grade II - IV aGVHD than that in those with grade 0 - I aGVHD (P = 0.02). There was no statistic difference in plasma sFasL levels between the infectious and non-infectious patients. In the seven grade II - IV aGVHD patients, the plasma sFasL levels pre-BMT were much lower than that in the six grade 0 - I aGVHD patients.

CONCLUSIONS

sFasL may be useful for the diagnosis of aGVHD and for differentiating aGVHD from other BMT related complications. The high level of plasma sFasL pre-BMT may be of importance in decreasing the occurrence of aGVHD after BMT.

[Cantonese population data of the tetranucleotide repeat locus D7S809 and its application in paternity test]

The tetranucleotide repeat locus D7S809 was investigated in Cantonese population by polymerase chain reaction (PCR) amplification, subsequent polyacryramide gel electrophoresis and silver staining. 14 alleles and 50 genotypes were detected in 190 sample individuals. All alleles differed in size by 4 bp repeat. No interalleles were found. The heterozygosity, power of discrimination and chance of non-paternal exclusion were 0.8613, 0.9645 and 0.7184 respectively. No significant deviations from Hardy-Weinberg equilibrium were found. The D7S809 was a highly polymorphic, stable and accurate type locus and had been successfully applied to 100 paternity test cases.

Dynamic changes of interleukin-1, interleukin-6 and tumor necrosis factor in intermingled skin graft in burned rats

OBJECTIVE

To compare the dynamic changes of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in intermingled skin graft with those in other types of skin grafts in rats.

METHODS

A 10%-15% third-degree burn was created in 180 Sprague-Dawley (SD) rats. After removing the scar, skin grafts were performed on the open wounds immediately with autoskin (aus, n=54), alloskin (als, n=54) and intermingled skin (n=36). That is to say, in the intermingled skin graft, a big piece of alloskin (mals) was grafted first, and 3 days later, small pieces of autoskin (maus) wer e embedded in the alloskin. The rest 36 rats were taken as the controls. And the biological activities of IL-1, IL-6 and TNF in graft sheets in each group were detected after skin graft.

RESULTS

The levels of IL-1, IL-6 and TNF in the aus group decreased steadily after their initial elevations, whereas in the als group they increased significantly and kept on the peak level in the later phases. In the in termingled group, there appeared a lowest IL-1 level in the mals and a highest one in the maus simultaneously at 7 (4) days (The number out of parenthesis is t he days after transplanting with alloskin sheets, and the number in parenthesis is the days after embedding autoskin sheets in the intermingled skin graft. Similarly hereinafter.) after skin graft (P<0.01), and the high level in the maus abruptly decreased at 14 (11) days after skin graft. At exactly the same phase on day 7 (4), a prominent peaked IL-6 in the mals occurred. In the later phases, the levels of TNF remained relatively low both in the m als and in the maus. From day 7 (4) on, each cytokine fluctuation in the mals synchronized with that in the maus. The longer the post transplantation period lasted, the more the positive cytokine correlated between the mals and the maus.

CONCLUSIONS

The low levels of IL-1 and TNF may be important f actors to lighten the intensity of local rejection in the intermingled skin graft. The temporarily peaked IL-6 is both an inducer which induces the production of local IL-1 receptor antagonists and soluble TNF receptors and a signal which indicates a local enhancement of Th(2) cells. The mild rejection process and th e synchronized cytokine level during the later phases suggest a possible chimerism between the mals and the maus.

[Inhibition of proliferation and induction of apoptosis by simvastatin in K562 leukemic cell line]

OBJECTIVE

To investigate the anti-apoptotic mechanism and explore approach to inhibiting proliferation and inducing apoptosis of chronic myclogenous leukemia (CML) cells.

METHODS

K562 cell line was used to evaluate the effects of simvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, and the combination of simvastatin with chemotherapeutic agents on the proliferation and apoptosis of CML cells.

RESULTS

Simvastatin could significantly inhibit proliferation and induce apoptosis of K562 cells, and could increase the sensitivity of K562 cells to chemotherapeutic agents. Addition of mevalonate, the immediate product of HMG-CoA, could completely reverse this effect.

CONCLUSION

Simvastatin inhibited proliferation and induced apoptosis of K562 cells through inhibiting the metabolic pathway of mevalonate. It is promising that HMG-CoA reductase inhibitors may be an effective chemotherapeutic approach to the treatment of CML.

Requirement of Ras-dependent pathways for activation of the transforming growth factor beta3 promoter by estradiol

It has been previously observed that the transforming growth factor beta3 (TGFbeta3) gene can be activated by both estradiol (E(2)) and selective estrogen receptor modulators (SERMs) in vivo but that only SERMs have a potent stimulatory effect on the TGFbeta3 promoter in cultured cells. We demonstrate in this report that E(2) can act also as a potent inducer of the TGFbeta3 promoter via a novel and specific estrogen receptor (ER)alpha-mediated mechanism. Our results show that treatment with epidermal growth factor or transfection of a constitutively active Ras mutant allows E(2) to induce the TGFbeta3 promoter via ERalpha in cotransfected HeLa and osteosarcoma MG63 cells. Both protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) inhibitors can block the combined stimulatory effect of E(2) and epidermal growth factor/Ras. However, E(2) induction of the TGFbeta3 promoter was found to be unaffected by mutation of ERalpha serine 118, a well-characterized target of MAPK. Progressive deletion analysis of the ERalpha amino-terminal region delineated three separate domains modulating the E(2)/activated Ras response, revealing a complex functional organization of the ERalpha A/B domain required for regulation of the TGFbeta3 promoter. In addition, PKC and MAPK inhibitors had no effect on the induction of TGFbeta3 promoter activity by the SERM EM-652. These results indicate that induction of the TGFbeta3 promoter by the E(2)/ERalpha complex requires the concomitant activation of PKC and MAPK signaling and provide a novel framework for the design of more effective estrogen-based therapeutic strategies.

A de novo complex chromosomal rearrangement with a translocation 7;9 and 8q insertion in a male carrier with no infertility

A de novo complex chromosomal rearrangement (CCR) involving chromosomes 7, 8 and 9 in a male carrier was ascertained through his healthy wife's recurrent spontaneous abortions. Six pregnancies over eight years resulted in four spontaneous abortions and two livebirths who died perinatally due to abnormal vital signs. Cytogenetic analyses utilizing high resolution chromosome banding technique showed a deletion of band in a der(7) chromosome and an extra band inserting at 8q21.2. Another extra band was also observed at the band 9p24, but it could not be karyotypically determined. Fluorescent in-situ hybridization using chromosome 7 and 8 specific microdissected library as probes confirmed the insertion of a segment from the translocated chromosome 7 into a chromosome 8, and additionally revealed a translocation between chromosomes 7 and 9. The karyotype of the CCR carrier was determined as 46,XY,t(7;9)(q22;p24),ins(8;7)(q21.2;q22q32).ish der(9)(wcp7+);ins(8;7)(wcp8+,wcp7+). Comparing with previously reported male CCR carriers with our case, we conclude that male CCR carriers may not always present with infertility or subfertility phenotypes. This may suggest that rare transmission of male carriers could result from abnormal chromosomal rearrangements during meiosis and gametogenesis in addition to frequent infertility.

[Association of single nucleotide polymorphisms in code region of beta2-adrenoceptor gene with hypertension in Chinese population]

OBJECTIVE

To detect single nucleotide polymorphisms(SNPs) existing in code region of beta(2)-adrenoceptor(2-AR) gene and to investigate association of the identified SNPs with essential hypertension in Chinese Han population.

METHODS

Beta(2)-AR gene was sequenced with fluorescent labelling automatic sequencing method in unrelated Chinese Han population from Dabie Mountain in Anhui Province. Genotype of the SNPs were typed with PCR-RFLP method.

RESULTS

Two SNPs were identified in length of 774bp, at position + 1053 with G-->C substitution and + 1239 with A-->G substitution respectively. The frequency of genotype of the two SNPs complied well with the Hardy-Weinberg equilibrium in normal group. Distribution of genotype AA, GA, GG of the SNPs at locus + 1239 in hypertension group was significantly different from that in normal group (chi(2) = 6.70, df = 2, P < 0.05). No significant difference was observed in distribution of genotypes of the SNPs at locus + 1053 between the two groups.

CONCLUSION

These results indicate that the SNPs at locus + 1239 of beta(2)-AR gene is associated with EH. The SNPs at position + 1053 was not linked to hypertension.

A bicistronic retroviral vector to introduce drug resistance genes into human umbilical cord blood CD34+ cells to improve combination chemotherapy tolerance

OBJECTIVE

To study whether human umbilical cord blood CD34+ cells transduced with human aldehyde dehydrogenase class-1 (ALDH-1) and multidrug resistance gene (MDR1) have increases resistance to 4-Hydroperoxycyclo-phosphamide (4-HC) and P-glycoprotein effluxed drugs.

METHODS

A bicistronic retroviral vector G1Na-ALDH1-IRES-MDR1 was constructed and used to transfect the packaging cell lines GP + E86 and PA317 by LipofectAMINE method, using the medium containing VCR and 4-HC agents for cloning selection and ping-ponging supernatant infection between the ecotropic producer clone and the amphotropic producer clone, we obtained high titer amphotropic PA317 producing cells with high titers up to 5.6 x 10(5) CFU/ml. Cord blood CD34+ cells were transfected repeatedly with supernatant of retrovirus containing human ALDH-1 and MDR1cDNA under the stimulation of hemopoietic growth factors.

RESULTS

Bicistronic retroviral vector construction was verified by restriction endonuclease analysis. Polymerase chain reaction (PCR), reverse transcription (RT)-PCR, Southern blot, Northern blot, fluorescenceactivated cell sorting (FACS) method and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analyses showed that dual drug resistance genes have been integrated into the genomic DNA of cord blood CD34+ cells and expressed efficiently. The transgenes recipient cells confered 4-fold stronger resistance to 4-HC and 5.5 to 7.2-fold P-glycoprotein effluxed drug than untransduced cells.

CONCLUSION

The bicistronic retroviral vector-mediated transfer of two different types of drug resistance genes into human cord blood CD34+ cells and co-expression provided an experimental foundation for improving combination chemotherapy tolerance in tumor clinical trial.

Y chromosome haplotypes reveal prehistorical migrations to the Himalayas

By using 19 Y chromosome biallelic markers and 3 Y chromosome microsatellite markers, we analyzed the genetic structure of 31 indigenous Sino-Tibetan speaking populations (607 individuals) currently residing in East, Southeast, and South Asia. Our results showed that a T to C mutation at locus M122 is highly prevalent in almost all of the Sino-Tibetan populations, implying a strong genetic affinity among populations in the same language family. Furthermore, the extremely high frequency of H8, a haplotype derived from M122C, in the Sino-Tibetan speaking populations in the Himalayas including Tibet and northeast India indicated a strong bottleneck effect that occurred during a westward and then southward migration of the founding population of Tibeto-Burmans. We, therefore, postulate that the ancient people, who lived in the upper-middle Yellow River basin about 10,000 years ago and developed one of the earliest Neolithic cultures in East Asia, were the ancestors of modern Sino-Tibetan populations.

Distribution of three HIV-1 resistance-conferring polymorphisms (SDF1-3'A, CCR2-641, and CCR5-delta32) in global populations

Chemokine receptors (CCR5, CXCR4 and CCR2) have been shown to be important co-receptors for HIV infection. Mutations at CCR5 (CCR5-delta2), CCR2 (CCR2-641), and stromal-derived factor SDF1 (SDF1-3'A), a primary ligand for CXCR4, are known to have protective effects against HIV-1 infection and the onset of AIDS symptoms. We studied the three-locus genotype frequency distributions in 70worldwide populations from a sample of 2341 individuals without any known history of HIV-1 infection and AIDS symptoms. From these data, we estimated the risk of AIDS onset (relative hazard, RH) of each population. This survey shows that the substantial allele frequency differences of each of these mutations translate into an extensive variation in relative hazards for AIDS in worldwide populations. However, no evidence of natural selection against the mutant gene carriers is detected. Finally, the combined three-locus genotype data predict the highest relative hazard (RH) in South-East Asia and Africa where AIDS is known to be more prevalent.

[Study on the relation between hypertensive left ventricular hypertrophy in very old people with neurohormonal factors and ventricular arrhythmias]

OBJECTIVE

To study the relation between hypertensive left ventricular hypertrophy (LVH) in very old people (> 80 year) with neuro-hormone factors and ventricular arrhythmias.

METHODS

Measurements were made on the heart rate variation, renin (Ren), angiotensin-II (AT-II), aldosterone (Ald), insulin (Ins), Holter and ambulatory blood pressure monitor in 60 cases of 2 groups: 30 with primary hypertension in very old people and LVH (group A); 30 with simple primary hypertension in very old people (group B).

RESULTS

(1) There was no significant difference of AT-II and Ren among group A and B (P > 0.05); (2) Ins and Ald value in group A was much higher than group B (P all < 0.01); (3) Very lower frequency (VLF) and low frequency (LF) and LF/HF (high frequency) in group A were significantly higher than group B (P < 0.01, 0.05, 0.05, respectively); (4) incidence of premature ventricular beats and myocardial ischemia in group A were higher than those in group B.

CONCLUSIONS

(1) Sympathetic nerve excitability in group A was greatly increased; (2) Hypertensive LVH were closely associated with Ald and Ins level, but not with AT-II and Ren; (3) There was obvious correction between group A and premature ventricular beats and ischemia.

[The application of competitive RT-PCR to detect minimal residual disease in patients with 8;21 translocation]

OBJECTIVE

To construct and evaluate the competitive quantitative RT-PCR method for detecting the fusion gene of AML1-ETO in the patients of t(8;21)AML(acute myeloid leukemia).

METHODS

The authors used the method of splicing by overlapping extension (SOE) to obtain the competitive DNA fragment, with which they set up the competitive quantitative RT-PCR assay to detect AML1-ETO chimeric genes in the patients of t(8;21) AML.

RESULTS

The competitive DNA fragment has been obtained; the sensitive competitive RT-PCR method is developed, which allows the quantitation of the number of AML1-ETO transcriptions in t(8;21)AML patients at different phases.

CONCLUSION

The competitive quantitative RT-PCR method, based on SOE, is simple and convenient; t(8;21) AML patients in different survival conditions express AML1-ETO gene quite differently.

[In vitro study on transduction of human O(6)-methylguanine-DNA-methyltransferase cDNA into human umbilical cord blood CD34(+) cells]

OBJECTIVE

To explore human umbilical cord blood hematopoietic progenitor cells transduced with human O(6)-methylguanine-DNA-methyltransferase (MGMT) gene increase resistance to 1,3-Bis(2-Chloroethyl)-1-Nitrosourea(BCNU).

METHODS

The present authors obtained a full length cDNA fragment encoding the human MGMT from a patient with cholelithiasis liver tissue by RT-PCR method and confirmed by DNA sequencing. The fragment was cloned into pGEM-T vector and further subcloned into G1Na retrovirus vector. Then the G1Na-MGMT was transfected into the packaging cell lines GP+E86 and PA317 by LipofectAMINE method; using the medium containing BCNU for cloning selection and ping-ponging supernatant infection between ecotropic producer clone and amphotropic producer clone, the authors obtained high titer amphotropic PA317 producer clone with the highest titer up to 1.6x10(6) CFU/ml. Cord blood CD34(+) cell were transfected repeatedly with supernatant of retrovirus containing human MGMT cDNA under stimulation of hemopoietic growth factors.

RESULTS

PCR, RT-PCR, Southern blot, Northern blot, Western blot and MTT analyses showed that MGMT gene had been integrated into the genomic DNA of cord blood CD34(+) cells and expressed efficiently in the transfected cells. The transgene recipient cells conferred 4 folds stronger resistance to BCNU than that of the non-transduced.

CONCLUSION

The retrovirus vector-mediated transfer of MGMT drug resistance gene into human cord blood CD34(+) cells and expression could confer the resistance of transgene cells to BCNU toxicity.

[The design, functions and clinic applications of lip bumper]

OBJECTIVE

This paper introduced the principle of design, methods of fabrication, indications and functions of lip bumper, and advocated the application of lip bumper in orthodontic clinic.

METHODS

Two typical cases treated with lip bumper were introduced. Some notices and experiences of applying lip bumpers were summed up.

RESULTS

There were following functions of lip bumper: as a space maintainer, Fränkel effect, headgear effect, post-maxillary expansion retention, derotation of molars, and combined using with headgear.

CONCLUSION

The advantages of lip bumper are inclusions of a wide range of indication, wearing for 24 hours per day, easily fabricating and prefabricating, comfortable and hidden for patients.

Spinal cord injury in rat: treatment with bone marrow stromal cell transplantation

We tested the hypothesis that transplantation of bone marrow stromal cells (MSCs) into the spinal cord after a contusion injury promotes functional outcome. Rats (n = 31) were subjected to a weight driven implant injury. MSCs or phosphate buffered saline was injected into the spinal cord 1 week after injury. Sections of tissue were analyzed by double-labeled immunohistochemistry for MSC identification. Functional outcome measurements using the Basso-Beattie-Bresnehan score were performed weekly to 5 weeks post-injury. The data indicate significant improvement in functional outcome in animals treated with MSC transplantation compared to control animals. Scattered cells derived from MSCs expressed neural protein markers. These data suggest that transplantation of MSCs may have a therapeutic role after spinal cord injury.