[Cloning and functional analysis of glnB from Azospirillum brasilense Yu62]

The glnB gene of A. brasilense Yu62 was determined in a 3.7 kb EcoRI + PstI fragment. The glnA is located downstream of glnB and an ORF for hypothetical protein is on upstream of glnB. The deduced amino acid sequence of PII encoded by glnB is 71%, 77%, 79% and 69% identical to that of K. pneumoniae, Bradyrhizobium japonicum, Rhizobium leguninosarum and E. coli, respectively. A Km-casette was inserted into BglII site of glnB coding region and GlnB- mutant was obtained by homologous recombination. The GlnB- mutant has lost the nitrogenase activity, i.e.: Nif-. For the functional confirmation of glnB gene, a complementary test was carried out and it was shown that C-glnB(glnB::Km/glnB) can restore the nitrogenase activity. When the recombinant plasmid pVK-II which containined the coding region of glnB was introduced into A. brasilense Yu62 and A. brasilense Yu62 DraT-, respectively, the Yu62-II (containing pVK-II) and draT-II(containing pVK-II) showed higher nitrogenase activity than wild type. These results confirmed that glnB plays an important role in the regulation of nitrogen in A. brasilense.

[Study on the fusion expression of FBXO30: a novel member of F-box protein family]

OBJECTIVE

The cDNA sequence of the coding region of FBXO30 (F-box only protein 30), which is a novel member of F-box protein family, was cloned into the mammalian expression vector pEGFP-C2 by non-directional cloning method and introduced into the NIH 3T3 cells by liposome transfection. Observation under the fluorescent microscopy after transfection showed that EGFP (enhanced green fluorescent protein)/FBXO30 was expressed and existed mainly in the cytoplasm. At the same time, the cDNA sequence of the coding region of FBXO30 was cloned into prokaryotic expression vector pGEX-4T-2 by directional cloning strategy. The GST (glutathione S-transferase)/FBXO30 fusion protein was expressed under the induction of IPTG (isopropylthio-beta-D-galactoside) in E. coli. A new band (approximately 65.5 kD) was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Purification of the GST-fused FBXO30 was carried out by affinity chromatography with glutathione sepharose 4B. The fusion expression of FBXO30 indicates that: FBXO30 protein is a cytoplasmic soluble protein, and the stable fusion expression of FBXO30 in the prokaryotic expression system can provide a base for the preparation of the specific antibody of FBXO30 and further functional study of FBXO30.

The snoRNA domain of vertebrate telomerase RNA functions to localize the RNA within the nucleus

Telomerase RNA is an essential component of the ribonucleoprotein enzyme involved in telomere length maintenance, a process implicated in cellular senescence and cancer. Vertebrate telomerase RNAs contain a box H/ACA snoRNA motif that is not required for telomerase activity in vitro but is essential in vivo. Using the Xenopus oocyte system, we have found that the box H/ACA motif functions in the subcellular localization of telomerase RNA. We have characterized the transport and biogenesis of telomerase RNA by injecting labeled wild-type and variant RNAs into Xenopus oocytes and assaying nucleocytoplasmic distribution, intranuclear localization, modification, and protein binding. Although yeast telomerase RNA shares characteristics of spliceosomal snRNAs, we show that human telomerase RNA is not associated with Sm proteins or efficiently imported into the nucleus. In contrast, the transport properties of vertebrate telomerase RNA resemble those of snoRNAs; telomerase RNA is retained in the nucleus and targeted to nucleoli. Furthermore, both nuclear retention and nucleolar localization depend on the box H/ACA motif. Our findings suggest that the H/ACA motif confers functional localization of vertebrate telomerase RNAs to the nucleus, the compartment where telomeres are synthesized. We have also found that telomerase RNA localizes to Cajal bodies, intranuclear structures where it is thought that assembly of various cellular RNPs takes place. Our results identify the Cajal body as a potential site of telomerase RNP biogenesis.

Analgesic effect of endomorphin-1

AIM

To study the analgesic effect of endomorphin-1 (EM-1).

METHODS

The experiment was performed in rats and mice to study the analgesic effect of intraperitoneal (ip) injection of EM-1 with tail stimulation-vocalization test, writhing test, adjuvant arthritis, and neuropathic pain model and to compare it with the analgesic effects produced by intracerebroventricular (icv) and intrathecal (it) administrations.

RESULTS

1) EM-1 raised the pain threshold dose-dependently in tail stimulation-vocalization test in rats and inhibited the writhing responses induced by ip acetic acid in mice. EM-1 also decreased the hyperalgesia in both adjuvant arthritis and neuropathic pain model. 2) The analgesic effect induced by central (icv and it) administration of EM-1 was faster and more powerful than that induced by peripheral (ip) administration. 3) The analgesic effect of EM-1 was reversed by naloxone (opioid receptor antagonist), as well as by cyprodime (mu-opioid receptor selective antagonist). Repeated administrations of EM-1 induced tolerance.

CONCLUSION

EM-1 had a definite analgesic effect and the analgesic effect of EM-1 was mediated by central mu-opioid receptor.

[A study on growth of Rhizobium leguminosarum in air pressure oscillating, solid-state fermenter]

Rhizobium leguminosarum L003, a kind of biofertilizers, was cultured in a periodic air pressure oscillating, solid-state fermenter by using straw of wheat as an inert solid support. Effects of air pressure oscillation amplitude, frequency on the viable cells of R. leguminosarum L003 and oxygen transfer rate were investigated. It was found that enhanced oxygen transfer and biochemical reaction occurred in this system. Under the optimized conditions, about a 3-fold increase of the viable cells was obtained in this system compared with that in a static tray fermenter. The overall oxygen transfer rate reached 487.01 mmol/(kg.h) in this system in case of 0.35 MPa, t2 = 0.5 min against 37.46 mmol/(kg.h) in static tray fermenter.

[Studies on the cell suspension culture of Saussarea medusa in a stirred tank bioreactor]

The cell suspension culture of Saussarea medusa in a 2L aerated and agitated bioreactor with a four-pitch-blade impeller was investigated. The effects of agitation speed, aeration and inoculum size on cell growth and flavonoids production were studied and it was found that cells had optimum growth and flavonoids production when cultivated at 75 r/min, 700-1000 L/min and an inoculum of 4.0-5.0 g/L. A high cell biomass of 13.8 g/L and flavonoids production of 416 mg/L were achieved after 12 days of cultivation. Time course study revealed that flavonoids biosynthesis was growth-associated. The studies on aggregates size distribution in the bioreactor showed that the aggregates break-up caused by hydrodynamic stress might adversely affect cell growth and lead to significant reduction of cell biomass and flavonoids production.

[Study on expression of the glycoprotein in myocardial cell membrane of the rat's early myocardial ischemic]

OBJECTIVE

To explore expression of the glycoprotein in early myocardial ischemic.

METHODS

The glycoprotein changes occurred at the early acute cardiac ischemic area induced experimentally by ligation of left coronary artery of 32 SD rats. 6 lectins were measured by means of immunohistochemical methods.

RESULTS

Positive staining of PNA could be observed in ischemic area at 5 min after ischemia, and the positive area increased with the prolongation of ischemic period. It became the strongest for 2 h and then decreased.

CONCLUSION

This experiment proved that myocardial cell membrane in ischemia expressed D-galactose. This may be of some value in forensic medicine practice.

Tricistronic viral vectors co-expressing interleukin-12 (1L-12) and CD80 (B7-1) for the immunotherapy of cancer: preclinical studies in myeloma

Synergy between interleukin-12 (IL-12) and B7-1 (CD80) for cancer immunotherapy has previously been demonstrated in animal models of breast cancer, lymphoma, and multiple myeloma. With a view to human clinical application, tricistronic retroviral and adenovirus vectors co-expressing IL-12 (IL-12p40 plus IL-12p35) and CD80 were constructed by utilizing two internal ribosome entry site (IRES) sequences to link the three cDNAs. A murine stem cell virus (MSCV)-based retroviral vector (MSCV-hIL12.B7) utilized distinct IRES sequences from the encephalomyocarditis virus (EMCV) and the foot-and-mouth disease virus (FMCV), whereas Ad5-based adenovirus vectors contained transcriptional units with two EMCV IRES sequences under the control of murine (AdMh12.B7) or human (AdHh12.B7) cytomegalovirus promoters. AdMh12.B7 was found to consistently direct higher levels of IL-12 and CD80 expression than AdHh12.B7 following infection of a number of human tumor cell lines. In preclinical studies, the human myeloma cell line U266 was infected with MSCV-hIL12.B7 and a resulting clonal cell line, U/MSCV-h12.B7, was generated with stable expression of CD80 and secreting IL-12 at 1 ng/24 h/10(6) cells. By comparison, following AdMh12.B7 infection, 81% of infected U266 cells (U/AdMh12.B7) expressed CD80 and secreted IL-12 at 25-50 ng/24 h/10(6) cells. Both engineered myeloma cell lines stimulated enhanced allogeneic mixed lymphocyte proliferation and provoked increases in cytotoxic T-lymphocyte responses and gamma-interferon release from normal donor lymphocytes exposed to parental U266 cells. These results suggest potential clinical utility of AdMh12.B7 in immunotherapy strategies for the treatment of multiple myeloma and other cancers.

Targeted correction of the point mutations of beta-thalassemia and targeted mutagenesis of the nucleotide associated with HPFH by RNA/DNA oligonucleotides: potential for beta-thalassemia gene therapy

An RNA/DNA chimeric oligonucleotide was found to be effective in the targeted correction of point mutations in Escherichia coli, plant, and mammalian genomes. This strategy, named chimeraplasty, has the potential for gene therapy of many genetic diseases caused by point mutations. beta-Thalassemia is a very common human genetic disease and in most cases it is caused by point mutations. To test whether the chimeraplasty can be used to correct the point mutations responsible for beta-thalassemia, we introduced one mutated beta-globin gene, betaE, into MEL cells and successfully corrected the point mutation of the betaE gene with the highest correction efficiency of 1.9%. Furthermore, a targeted -202 C-->G mutation of the Ggamma-globin gene, which is associated with the elevated Ggamma-globin gene expression in the adult stage, was introduced into HeLa and CMK cells by an RNA/DNA oligonucleotide. These results indicated that the chimeraplasty has potential for human beta-thalassemia gene therapy.

A 1.2-A snapshot of the final step of bacterial cell wall biosynthesis

The cell wall imparts structural strength and shape to bacteria. It is made up of polymeric glycan chains with peptide branches that are cross-linked to form the cell wall. The cross-linking reaction, catalyzed by transpeptidases, is the last step in cell wall biosynthesis. These enzymes are members of the family of penicillin-binding proteins, the targets of beta-lactam antibiotics. We report herein the structure of a penicillin-binding protein complexed with a cephalosporin designed to probe the mechanism of the cross-linking reaction catalyzed by transpeptidases. The 1.2-A resolution x-ray structure of this cephalosporin bound to the active site of the bifunctional serine type D-alanyl-D-alanine carboxypeptidase/transpeptidase (EC ) from Streptomyces sp. strain R61 reveals how the two peptide strands from the polymeric substrates are sequestered in the active site of a transpeptidase. The structure of this complex provides a snapshot of the enzyme and the bound cell wall components poised for the final and critical cross-linking step of cell wall biosynthesis.

Enhancement of proliferation and differentiation of erythroid progenitors by co-transduction of erythropoietin receptor and H-ras cDNAS into single CD34(3+) cord blood cells

Our previous studies have demonstrated that retrovirus-mediated gene transduction of either the human erythropoietin receptor (EpoR) or H-ras cDNA into single purified hematopoietic progenitor (HPC), CD34(3+), cells from cord blood (CB) resulted in increased numbers and sizes of erythroid cell containing colonies. We therefore evaluated if there were further effects when H-ras and EpoR genes were co-transduced into the same progenitor cells. Highly purified single sorted CD34(3+) CB cells were transduced with retroviral vectors encoding EpoR or H-ras cDNA. At the single cell level, and in response to stimulation by a combination of growth factors, including Epo, the number of colonies formed by BFU-E and CFU-GEMM was significantly increased in cells transduced with either single H-ras or EpoR cDNA compared to mock virus-transduced cells as previously described. Increased numbers of BFU-E, but not CFU-GEMM, colonies were produced from cells simultaneously co-transduced with both EpoR and Hras genes. Little or no growth was seen in transduced cells without exogenously added cytokines. The size of all types of colonies including CFU-GM was increased in cells transduced with H-ras and/or EpoR cDNAs, and the greatest increase was noticed in cells co-transduced with both genes. Integration and expression of either gene in individual colonies as assessed by PCR and RT-PCR analysis were 45-62% and 48-58%, respectively, with approximately 31% of the cells containing and expressing both genes. These results add to information suggesting an enhancing interacting role of H-ras and EpoR in erythroid proliferation/differentiation.

Phylogenetic analysis of the S7 gene does not segregate Chinese strains of bluetongue virus into a single topotype

Bluetongue virus (BTV) infection of ruminants is endemic throughout tropical and subtropical regions of the world. The S7 gene segments of prototype Chinese strains of BTV serotypes 1, 2, 3, 4, 12, 15, and 16 were sequenced and compared to the same genes of prototype strains of BTV from the US, Australia, and South Africa. The S7 genes and predicted VP7 proteins of the Chinese viruses were relatively conserved, with the notable exception of serotype 15. Furthermore, phylogenetic analysis of the S7 genes did not predict geographic origin of the various strains of BTV.

[Production of u-PA with rCHO cell culture on porous microcarriers in serum-free growth medium]

A novel technique was developed to deal with apoptosis in large-scale animal cell culture. By means of replacing part of Cytopore porous microcarriers at regular intervals, a rCHO cell line, which produces urokinase-type plasminogen activitor(u-PA), was cultivated continuously with serum-free medium in a 30 L stirred tank for 91 days. The cell density was maintained at (1.3-2.6) x 10(7)/mL, and > 90% of cells was viable. In order to reduce the effect of cell density on cell growth and expression, a cyclic pressure oscillation was exerted on a 7.5 L reactor headspace to enhance cell expression at high cell density to a certain extent. During the 67 days of medium-replacement culture, the maximal cell density reached 2.64 x 10(7)/mL, and cell viability was always kept above 95% when combined with microcarrier-replacement. Compare to control culture, culture with cyclic pressure oscillation could enhance cell expression level and reduce the ratio of glucose metabolized anaerobically to produce lactate. With four-step purification process, about 80 g u-PA(approximately 90% scu-PA) was recovered from approximately 2100 liters supernatant which contained approximately 135 g u-PA.

[Gas chromatographic determination of camphor, menthol, methyl salicylate, thymol in JEIL COOL PAP]

The contents of camphor, menthol, methyl salicylate and thymol in JEIL COOL PAP were determined with gas chromatography by using a stainless steel column (2 m x 3 mm i.d.) packed with 15% DEGS, Chromosorb W (AW-DMCS) 80-100 mesh. Temperature programming was from 70 degrees C to 180 degrees C. The quantitative determination was performed with diphenyl as the internal standard. The internal standard method showed good linearity (r = 0.9995-0.9999). The average recoveries were 99.63% (camphor), 99.83% (menthol), 100.0% (methyl salicylate) and 100.4% (thymol).

[Spectrophotometric determination of copper in the hair of the patients with rheumatoid arthritis]

A new color reaction of copper (II) with solochrome cyanine R was studied by spectrophotometry. The results were that in the pH6 of HAc-NaAc buffer solution solochrome cyanine R reacted with copper (II) to form a violet complex; the maximum absorption of the complex was at 565 nm and its apparent molar absorption coefficient was 8.25 x 10(5) L.mol-1.cm-1. Beer's Law was obeyed in the range of 0-0.48 microgram.ml-1. This method was used to determine copper levels in the hair samples of 5 normal persons and 5 rheumatoid arthritis patients. The results showed that the hair copper level of arthritis patients was significantly higher than that of normal persons (P < 0.01).

Effect of nitric oxide on electric and mechanical activities of gastric antral circular muscles in guinea pigs

AIM

To study the effect of exogenous nitric oxide (NO) on electric and mechanical activities of gastric antral circular muscle in guinea pigs in vitro.

METHODS

Mechanical and electric activities of gastric antral circular muscle in guinea pigs were recorded simultaneously.

RESULTS

Sodium nitroprusside (SNP, 0.5 mumol.L-1), an NO donor, inhibited the frequency and amplitude of fast wave and spontaneous contraction of the strips (P < 0.01). SNP-induced inhibition was not blocked by tetrodotoxin, atropine, phentolamine, and propranolol (P > 0.05), but diminished by methylene blue (P < 0.01) and oxyhemoglobin (P < 0.01).

CONCLUSION

Exogenous NO inhibits gastric antral myoelectric and mechanical activities in guinea pigs. The inhibitions are produced by NO acting on extracellular membrane and enhancing the level of cGMP.

A light-inactivated antibiotic

Sodium 7beta-[(R)-2-(N(b)()-o-nitrobenzyloxycarbonyl)hydrazino-3-pheny lpropa namido]cephalosporanate (1) is described as a new type of beta-lactam antibiotic, which undergoes light-induced destruction of its beta-lactam moiety and hence becomes biologically inactive. This type of antibiotic holds the promise of self-destruction over a number of hours of exposure to light, so that it would not allow selection of resistance in the environment.

[Clinical analysis of vocal cord leukoplakia in 32 cases]

OBJECTIVE

To investigate the types and curative effects of the leukoplakia of the vocal cord.

METHOD

From 1990 to 1996, 32 patients (38 sides) with leukoplakia of vocal cord were operated in our hospital, postoperative follow-up ranged from 2 to 7 years.

RESULT

There were eighteen cases of simple leukoplakia and fourteen cases of leukoplakia with mild, moderate and severe atypical hyperplasia in this study. None of simple leukoplakia had malignant change. But there were 33%, 75% and 75% of cases had malignant change in the leukoplakia with mild, moderate and severe atypical hyperplasia respectively. To surgical methods, there was no significant difference, in the rate of malignant change either by the microlaryngoscopy or thyrotomy.

CONCLUSION

Simple leukoplakia can be cured. More attention should be paid to the leukoplakia with any types of atypical hyperplasia during clinical management. The postoperative results were not depend on the surgical methods.

Anatomic basis of iliac crest flap pedicled on the iliolumbar artery

This paper presents the anatomy and clinical applications of an iliac crest flap pedicled on the iliolumbar artery. 54 iliolumbar arteries were filled with pink plastic in 27 adult cadavers. Their origin, course and branches, and the surroundings were investigated, and the external diameter, length of segments and terminal distribution were measured. The iliolumbar artery was constant, but with a few variations. Its length was 7.0 +/- 3.9 cm, and the outer diameter 2.0 +/- 0.4 mm at the lateral edge of the psoas major muscle. Based on the anatomic findings, the surgical technique for a bone flap based on the iliolumbar artery was designed. Its clinical applications included both free bone grafting (in 2 patients) and pedicled bone transfer (in another 2 patients). The clinical results were satisfactory. The iliac crest flap pedicled on the iliolumbar artery is a reliable bone flap for clinical usage.

[Construction of expressing vector for phage display scFv and a mouse unspecified antibody library]

The display of antibody gene library on the surface of E. coli filamentous phage offers a new method of obtaining antibodies against specific antigens. In the paper, it is reported that a phagemid for phage display antibody, named after pFUW80, characterized expressing scFv either secretly or stickily. With a series of designed PCR primers, heavy-chain and light-chain variable region genes of mice antibodies were amplified and a mouse unspecified single-chain antibody library with the size of 1.2 x 10(6) clones was constructed. From this library, phage was selected out against antigen human IgG and detected by ELISA and partial sequence analysis. These primary results established the foundation for future research using this system.

Adipocyte differentiation factor (ADF): a protein secreted by mature fat cells that induces preadipocyte differentiation in culture

A factor that is released into the culture medium of mature adipocytes and promotes the differentiation (adipogenic conversion) of preadipocytes has been partially characterized. The factor acts in a dose-dependent manner on preadipocytes to produce up to a four-fold increase in triacylglycerol (triglyceride) content and a nine-fold increase in glycerol-3-phosphate dehydrogenase (GPDH) activity, a marker of the late phase of differentiation of preadipocytes. The material appears to be a protein, since it has a molecular weight (Superose-12 gel exclusion chromatography) of about 53 kDa, an isoelectric point (pl) of 4.7-4.9, and is inactivated by the proteases papain and chymotrypsin and extremes of pH (2 and 12). Considerations of molecular weight, isoelectric point, stability to specific proteases, and especially to the action of chemical agents [the adipogenic activity is not affected by either an oxidizing (KIO4) or a reducing agent (DTT)], lead to the conclusion that the differentiation factor is distinct from known cytokines. The authors suggest that the protein be designated adipocyte differentiation factor (ADF). ADF in vivo may act as a cytokine paracrine agent to regulate the differentiation of preadipocytes.

Neurophysiology of magnocellular neuroendocrine cells: recent advances

Magnocellular neuroendocrine cells of the hypothalamic paraventricular and supraoptic nuclei are responsible for most of the vasopressin and oxytocin in the peripheral blood as well as for central release of these peptides in selected brain areas. As the principal component of the hypothalamo-neurohypophysial system, these neurons have been a subject of continual study for half a century. The wealth of solid information from decades of in vivo studies has provided a firm basis for in vitro, brain slice and explant investigations of neural mechanisms involved in the control and regulation of vasopressin and oxytocin neurons. In vitro methods have revealed the presence and permitted the study of monosynaptic projections to supraoptic neurons from the olfactory bulbs, the tuberomammillary nuclei of the posterior hypothalamus and from the organum vasculosum of the lamina terminalis. Such methods have also facilitated the elucidation of the various ionic currents controlling neurosecretory cell activity as well as the roles of calcium binding proteins and release of calcium from internal stores. This review summarizes recent advances in our understanding of the afferent inputs that impinge upon these two cell types, and the cellular and molecular mechanisms intrinsic to these neurons that determine their activity patterns and, in part, their responses to incoming stimuli.

[Observation of repair of wounded rat skin by affinity histochemical method of SJA]

Time expression of SJA tissue receptors surrounding wounded skin of 40 rats was studied by affinity histochemical method. The results were compared to that by EGFR immunohistochemical method and c-myc situ hydridization method. It was observed that SJA receptors began to decrease after the skin was injured and reached the lowest quantities in 15 minutes. After that, they began to increase and reached the highest quantities in 2 hours. It needs to be further studied whether there is the correlation between SJA receptors and EGFR has the function of repairing wounded skin.

Inversion and transposition of Tc1 transposon of C. elegans in mammalian cells

Tc1/mariner transposons are widespread in the eukaryotes. In vitro transposition test indicated that the transposase is the only protein that is needed in transpositions. It was shown later that the reconstructed Tc1-like transposon, "sleeping beauty" in fish, and the Tc1 transposon in C. elegans jumps in human cells. This discovery indicates that the Tc1/mariner transposon may be engineered as a somatic gene therapy vector if coupled with an efficient gene delivery system. We introduced the Tc1 transposon from C. elegans into different mammalian cell lines and detected the transposition events, indicating that Tc1 transposon functions in different mammalian cells. Interestingly, a high inversion frequency of the transposon was also detected, suggesting that this type of transposon may add variations to host genome when it is horizontally transferred into a new species.

[The absolute configurations and biological activities of alpha- and beta-anordrins]

The molecular structures and absolute configurations of alpha- and beta-anordrins are reported. Animal experiments showed that pure alpha-epimer possessed high anti-implantation and anti-early pregnancy effects, but the pure beta-epimer exhibited very low effects at the same dose. MNDO program was applied for the optimization of the configurations of epimers to establish the isolated molecular configurations and calculate the quantum chemical indexes. The results showed that the configurations and the differences of action field in three-dimensions of alpha- and beta-epimer are probably the factors that the alpha-epimer exhibited biological activity.

Tracing cell fates in human colorectal tumors from somatic microsatellite mutations: evidence of adenomas with stem cell architecture

Occult aspects of tumor proliferation are likely recorded genetically as their microsatellite (MS) loci become polymorphic. However, MS mutations generated by division may also be eliminated with death as noncoding MS loci lack selective value. Therefore, highly polymorphic MS loci cannot exist unless mutation rates are high, or unless mutation losses are inherently minimized. Mutations accumulate differently when cell fates are determined intrinsically before or extrinsically after division. Stem cell (asymmetrical division as in intestinal crypts) and random (asymmetrical and symmetrical division) proliferation, respectively, represent simulated cell fates determined before or after division. Whereas mutations regardless of selection systematically persist once inherited with stem cell proliferation, mutations are eliminated by the symmetrical losses of both daughter cells with random proliferation. Therefore, greater genetic diversity or MS variance accumulate with stem cell compared with random proliferation. MS loci in normal murine intestinal mucosa and xenografts of cancer cell lines accumulated mutations, respectively, consistent with stem cell and random proliferation. Tumors from patients with hereditary nonpolyposis colorectal cancer (HNPCC) demonstrated polymorphic MS loci. Overall, three of five adenomas and one of six cancers exhibited high MS variances. Assuming mutation rates are not significantly greater in adenomas than in cancers, these studies suggest the stem cell proliferation and hierarchy of normal intestines persists in many HNPCC adenomas and some cancers. An adenoma stem cell architecture can explain the complex polymorphic MS loci observed in HNPCC adenomas and account for many adenoma features. In contrast, cancers may lose intrinsic control of cell fate. These studies illustrate a feasible phylogenetic approach to unravel and describe occult aspects of human tumor proliferation. The switch from predominantly stem cell to random proliferation may be a critical and defining characteristic of malignancy.

Functions of purified gB, gE:gI, and gH:gL, and their sialyl residues in varicella-zoster virus infection

Varicella-zoster virus glycoproteins were purified by using monoclonal antibodies and analyzed for their effects on cell-free virus infection. Preinfection treatment of cells with gH:gL reduced the infection efficiency and increased the number of unadsorbed virus. Postinfection treatment of cells with gB increased the infection efficiency, but that with gE:gI reduced it. Treatment of gE:gI and gH:gL with neuraminidase (NA) abolished their inhibitory activity and the plaque formation was enhanced by NA treatment of glycoproteins and cells. Glycoproteins exhibited their diverse activities despite their common role in viral penetration, and sialyl residues were responsible for their function in cell-free virus infection.

Involvement of H-ras in erythroid differentiation of TF1 and human umbilical cord blood CD34 cells

To investigate the role of the ras gene in erythroid differentiation, a human erythroleukemic cell line, TF1, was transduced with a selectable retroviral vector carrying a mammalian wild type H-ras gene or a cytoplasmic dominant negative RAS1 gene. Transduction of TF1 cells with the wild type H-ras gene resulted in changes of cell types and up-regulation of erythroid-specific gene expression similar to that seen in differentiating erythroid cells. The number of red blood cell containing colonies derived from TF1 cells transduced with wild type H-ras cDNA was significantly increased and the cells in the colonies were more hemoglobinized as estimated by a deeper red color compared to those colony cells from mock or dominant negative RAS1 gene transduced TF1 cells, suggesting increased erythroid differentiation of TF1 cells after transduction of wild type H-ras in vitro. The mRNA levels of beta- and gamma-, but not alpha-, globin genes were significantly higher in H-ras transduced TF1 cells than those in TF1 cells transduced with mock or dominant negative RAS1 gene. Moreover, a 4kb pre-mRNA of the Erythropoietin receptor (EpoR) was highly expressed only in H-ras transduced TF1 cells. Additionally, human umbilical cord blood (CB) CD34 cells which are highly enriched for hematopoietic stem/progenitor cells were transduced with the same retroviral vectors to evaluate in normal primary cells the activities of H-ras in erythroid differentiation. Increased numbers of erythroid cell containing colonies (BFU-E and CFU-GEMM) were observed in CD34 cells transduced with the H-ras cDNA, compared to that from mock transduced cells. These data suggest a possible role for ras in erythroid differentiation.

A live non-neurovirulent herpes simplex virus vector expresses beta-galactosidase in the nervous system of the Wistar and Sprague-Dawley strain rat for a prolonged period

We have constructed a live non-neurovirulent herpes simplex virus vector expressing beta-galactosidase under the control of the latency associated transcript promoter without inducing inflammation. Pathogenicity of the recombinant virus (betaH1) was not observed in the cutaneous, intravenous and intracerebral infection in mice. When betaH1 was inoculated at the caudate putamen of rats, beta-galactosidase activity was observed in neurons at the inoculation site and its projecting frontal cortex. Expression of beta-galactosidase was observed in the neurons of the innervating dorsal root ganglia 45 days after inoculation of betaH1 into the hind paws of the rats. Neither inflammation nor tissue destruction was observed in both neural tissues in this study. Thus this non-neurovirulent recombinant virus is a suitable vector for expressing the foreign genes in the nervous system for the prolonged period.

Transduction of recombinant human erythropoietin receptor cDNA into daughter progenitors derived from single CD34(3+) cord blood cells changes the differentiation profile of daughter progenitors

In this study, we tested the capacity to change the differentiation profile of progenitor cells by retroviral-mediated transduction of EpoR cDNA into one of the paired daughter cells derived from single CD34(3+) CB cells. Our results show that for the non-viral-treated daughter cells, the majority (99.6%) formed the same colony type. However, with cells transduced with viral vectors, 7.1% of the daughter cells transduced with the EpoR cDNA formed either a burst forming unit-erythroid (BFU-E) or a colony-forming unit-granulocyte, macrophage, erythroid, megakaryocyte (CFU-GEMM) colony compared to the other daughter cell transduced with viral supernatant lacking EpoR cDNA, which formed either a colony-forming unit granulocyte-macrophage (CFU-GM) or a high proliferative potential-colony forming cell (HPP-CFC) colony. Expression of the transduced EpoR cDNA was confirmed in individual colonies by RT-PCR analysis. These results substantiate in a more rigorous fashion our previous results that it is possible to change the Epo-responsive differentiation profile of progenitor cells by transduction into these cells of an EpoR cDNA and this change was apparent only in daughter cells derived from single CD34(3+) kit+ cells transduced with EpoR cDNA.

A novel type of structurally simple nonpeptide inhibitors for alpha-chymotrypsin. Induced-fit binding of methyl 2-allyl-3-benzenepropanoate to the S2 subsite pocket

Unexpectedly, methyl and benzyl esters of 2-allyl-3-benzenepropanoic acid were found to be not substrates but potent competitive inhibitors for alpha-chymotrypsin. The inhibitory property of the structurally simple nonpeptidic compounds is ascribed to their high binding affinity to the enzyme at the S2 rather than S1 subsite pocket. These inhibitors exist in a flexible form in solution, but as they bind to the enzyme bulky contrained conformers present in a minute concentration play an important role, forming tighter enzyme.inhibitor complexes by binding to the large hydrophobic S2 pocket. The contrained conformers are thought to be resulted from intramolecular CH/pi interactions between a vinylic proton and the aromatic pi-electron cloud in the inhibitor molecules. These compounds constitute novel examples of the induced-fit binding inhibitor of possibly simplest structure.

Wild-type p53 gene increases MDR1 gene expression but decreases drug resistance in an MDR cell line KBV200

Inactivation of p53 gene and overexpression of MDR1 gene are both associated with drug resistance. Previous studies have suggested that p53 gene can modulate the expression activity of MDR1 gene promoter in a promoter-CAT system. In the present study, wild-type p53 gene cDNA was introduced into a multidrug-resistant cell line, KBv200, in which endogenous p53 gene is aberrant. In wt-p53 transfected cells, the expression of MDRI gene was significantly increased, accumulation of adriamycin (ADM) was decreased, and the sensitivity to vincristine (VCR), ADM and 5-fluorouracil (5-FU) was increased compared with the parent KBv200 cells. After treatment with ADM and VCR, the p53-transfectants were more susceptible to apoptosis. The results suggest that the increase in drug sensitivity of the cells may be, at least in part, due to p53-dependent apoptosis induced by anticancer agents.

[Effect of chaihu guizhi decoction on the immunoglobulin and IgG subgroup in children with recurrent respiratory tract infection]

OBJECTIVE

To observe the effect of Chaihu Guizhi Decoction (CGD) on Immunoglobulin (Ig) and IgG subgroup in children with recurrent respiratory tract infection (RRTI).

METHODS

Levels of Ig and IgG subgroup were measured in 23 cases of children with RRTI before and after treating with CGD, and compared with those in the control group.

RESULTS

In RRTI group, the levels of IgG, IgA, IgM and IgG1 were lower than those of the control groups respectively (P < 0.01). The rate of IgG subgroup deficiency (ISD) was 60.9%. The effective rate of the CGD group was 95.6%. The IgG and IgG1 levels were increased after treatment as compared with before treatment (P < 0.05), and the ISD correcting rate being 71.4%.

CONCLUSIONS

The hypoimmunofunction and IgG subgroup deficiency were important factors in RRTI pathogenesis. The CGD could improve the immunofunction and correct the IgG subgroup deficiency, and this effect might be one of the mechanism of CGD in treating RRTI.

Up-regulation of Tie gene expression by leukemia inhibitory factor and steel factor in CD34+ cells from human umbilical cord blood

Tie, a new receptor tyrosine kinase, is expressed in vascular endothelial and hematopoietic cells. To determine whether Tie might be involved in early hematopoiesis, we asked whether the Tie gene is expressed in normal human hematopoietic stem/progenitor cells and if the expression of this gene could be regulated. Using a single-cell reverse-transcriptase polymerase chain reaction (RT-PCR) assay to study expression of the Tie gene in the subset of human umbilical cord blood (UCB) CD34+++ primitive stem/ progenitor cells with extensive replating capacity, we demonstrated at the single isolated cell level that Tie was expressed in these cells. The expression of Tie gene in CD34+ cells was at a low level but was enhanced up to two- to fourfold by steel factor (SLF) or leukemia inhibitory factor (LIF), two cytokines that regulate production of stem/progenitor cells, as assessed using competitive PCR and semi-quantitative RT-PCR assays. The fold increases were observed as early as 2 h for SLF and 4 h for LIF and remained elevated for 24 h. These results demonstrate modulation of gene regulation in the rare populations of CD34+ cells and suggest the possibility that Tie may play a role in the proliferation and differentiation of immature hematopoietic cells.

[Wild-type p53 stimulates vincristine-induced apoptosis]

Recent studies indicate that wild-type p53 can trigger cell apoptosis induced by many chemotherapeutic agents which induce DNA damage or cause disruptions of DNA metabolism, such as ADM, 5-FU, VP-16 and radiation. We introduced the wild-type p53 gene into a MDR cell line KBV200 in which the endogenous p53 was found to be rearranged. By G418 selection and Northern blot analysis, a G418-resistant clone named KBV200-p53 was obtained which continuously expressed the exogenous wild-type p53 mRNA. After treatment with Vincristine(VCR), the wild type p53-expression cells presented typical morphology characteristic of apoptosis analysed under electron and fluorescence microscopes. Flow cytometer analysis showed that the KBV200-p53 cells were more readily undergo apoptosis than their parental cells KBV200. After treatment with VCR 600 nmol.L-1 for 24 h, the apoptotic percentage of KBV200-p53 and KBV200 cells was about 42.4% and 8.4%, respectively. This result indicates that wild-type p53 stimulates VCR-induced apoptosis in KBV200 cells.

[Clinical study on treatment of arteriosclerosis obliterans using huangqi tongmai decoction]

OBJECTIVE

To test and verify the effects of Huangqi Tongmai Decoction (HQTMI) regulating blood lipid in treating arteriosclerosis obliterans (ASO).

METHODS

Thirty-two cases of ASO was treated with HQTMD for two months. The drug was in water decoction, oral taken.

RESULTS

Compared with the blood lipid level before treatment, the high density lipoprotein of cholesterol (HDL-C) was increased, the low density lipoprotein of cholesterol (LDL-C), atherogenic index (AI) was decreased (P < 0.01). The serum total cholesterol (TC), triglyceride (TG), very low density lipoprotein of cholesterol (VLDL), apolipoprotein A1 (apoA1), apolipoprotein B100 (apoB100) were all changed (P < 0.05). apoA1/apoB100 ratio increased.

CONCLUSION

HQTMD could regulate blood lipid. This method was effective in treating ASO.

[Endoscopic papillosphincterotomy for the treatment of pancreaticobiliary disease]

From July 1987 to March 1996, endoscopic papillosphincterotomy (EST) was performed in 346 patients of 2,700 cases undergoing ERCP. Maj or indications for EST were choledocholithiasis, constrictive papillitis, chronic pancreatitis, biliary ascariasis and dysfunction of Oddi's sphincter. The EST was successful in 331 cases, ang the overall success rate was 95.7%. The stone discharge rate was 96%. The stricturotomy rate was 93.8%. The failure rate was 4.3% (15 cases). Clinical application and prevention of complications for EST were discussed.

Pharmacokinetics of cidofovir in monkeys. Evidence for a prolonged elimination phase representing phosphorylated drug

After intravenous administration of [14C]cidofovir to African green monkeys (43 mg/kg, 29.5 microCi/kg), the drug distributed rapidly into extracellular fluid. Concentrations of radioactivity in plasma were described by a three-compartment model with alpha, beta, and gamma half-lives of 0.67, 3.02, and 36.0 hr, respectively (N = 3). These phases are believed to represent renal elimination, efflux of free cidofovir from cells, and efflux from cells of cidofovir produced from dephosphorylation of metabolites, respectively. Less than 5% of the dose was phosphorylated, based on the proportion of total AUC in the gamma-phase. The clearance of cidofovir (211 +/- 16.6 ml/hr/kg) was dependent on dose and exceeded the theoretical glomerular filtration rate. Concentrations of cidofovir in kidney declined with a half-life of 23 hr and were > 1,000-fold higher than plasma levels by 120 hr. Clearance of cidofovir after multiple intravenous doses of 4.9 mg/kg/day (18.5 microCi/kg/day) decreased significantly by day 10, consistent with the observed nephrotoxicity. Oral and subcutaneous bioavailabilities of cidofovir were 21.8 +/- 9.44 and 98.5 +/- 15.8%, respectively. After intravenous administration of [14C]cidofovir to cynomolgus monkeys (10 mg/kg, 100 microCi/kg) alone or 1 hr after oral probenecid (30 mg/kg), mean +/- SD (N = 3) urinary recoveries of total radioactive dose were 91.4 +/- 11.3% and 94.4 +/- 29.8%, respectively, at 7 days postdose. The mean +/- SD half-lives of the terminal elimination phases were 33.3 +/- 10.6 and 24.4 +/- 5.0 hr, respectively. Cidofovir accounted for 98% of the radioactivity recovered in urine; the remainder was attributed to cidofovir phosphocholine. The prolonged elimination phase observed in monkeys is consistent with the long intracellular half-life of phosphorylated cidofovir in vitro and supports infrequent dosing of the drug for antiviral therapy.

Macrophage-stimulating protein, a ligand for the RON receptor protein tyrosine kinase, suppresses myeloid progenitor cell proliferation and synergizes with vascular endothelial cell growth factor and members of the chemokine family

Macrophage-stimulating protein (MSP), originally identified as an inducer of murine resident macrophage responsiveness to chemoattractants, is a ligand for human RON/murine STK receptor protein tyrosine kinases. Since STK was cloned from populations enriched for hematopoietic stem cells, we initiated studies on the effects of MSP on colony formation by granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) myeloid progenitor cells. MSP alone had no colony stimulating activity. However, MSP caused about a 50% suppression of CFU-GM colony formation induced by synergistic combinations of SLF or Flt-L plus GM-CSF, G-CSF, or IL-3 and of BFU-E and CFU-GEMM colonies induced by SLF or Flt3-L plus Epo or Epo and IL-3. In contrast, MSP had no effect on progenitors stimulated by one growth factor. MSP also suppressed colony formation by stimulated cord blood progenitors, but only after preinduction to a rapidly cycling state. It was previously reported that several members of the chemokine family synergistically suppress myeloid progenitor proliferation. Likewise, synergistic suppression was observed when MSP was paired with VEGF, MIP-1 alpha, IL-8, PF4, MCP-1, IP-10, or ENA-78, or when VEGF was paired with the chemokines; and the required MSP concentration was more than 100-fold less than for MSP alone. Additionally, MSP or VEGF inhibited proliferation of the human myeloid growth factor-dependent cell line, M07e, but a sustained effect required multiple additions over time. At the least, some of the MSP suppressive effects on myeloid progenitors, as assessed on single isolated CD34 marrow cells, appeared to be directly on the progenitors; sustained additions of MSP were required to see this effect. The suppressive action of MSP and its synergism with proteins of the chemokine family may be of relevance to regulation of blood cell production.

Somatic microsatellite mutations as molecular tumor clocks

Microsatellite (MS) mutations can potentially unravel the past of mutator phenotype tumors, with greater genetic diversity expected in older regions. Rapid clonal expansions of xenografts were characterized by relatively homogenous MS alleles, whereas greater diversity was observed in a colorectal cancer with the greatest variation in its adjacent adenoma. A subcutaneous lung cancer metastasis demonstrated diversity consistent with its one-month clinical duration and evidence of active mitosis during dormancy. The genetic legacy inherent to multistep tumorigenesis provides direct estimates of tumor ages, with up to thousands of cell divisions and high death rates necessary to yield the observed diversities. MS molecular tumor clocks have the unique potential to systematically reconstruct the early and occult evolution of individual human mutator phenotype tumors.

Effects of mutation and growth rates on patterns of microsatellite instability

The detection of somatic microsatellite (MS) alterations in tumors is often interpreted as a sign of underlying genomic instability. However, it is unclear why the proportions of altered MS loci vary between different mutator phenotype tumors. We present a simple mathematical analysis that can account for some of these differences, recognizing that the mutations accumulated in a tumor reflect both its mutation rate and number of cell divisions. Only a small proportion of mutated MS loci are expected in tumors with normal or low mutation rates. In contrast, tumors with high mutation rates may or may not acquire mutations depending on the numbers of divisions that proceed the onset of the mutator phenotype. The majority of MS loci should accumulate mutations if high mutation rates are acquired early in tumor progression. Somatic MS mutations provide clues to both the mode and tempo of tumori-genesis.

Telomerase activity is commonly detected in hereditary nonpolyposis colorectal cancers

Telomerase activity can be detected in most human cancers. These findings are consistent with the telomere hypothesis, which predicts telomerase expression after a number of mitotic divisions to prevent the progressive and catastrophic loss of telomeres. However, telomerase is not detected in a minority of colorectal cancers suggesting either alternative mechanisms of immortalization or that their telomeres have not yet shortened sufficiently to require telomerase activity. Colorectal cancers arising in patients with hereditary nonpolyposis colorectal cancer (HNPCC) were examined for telomerase activity because compared to sporadic tumors, HNPCC tumors are less likely to pass a telomere threshold as they occur in younger patients and exhibit "accelerated" progression, perhaps because of their characteristic mutator phenotypes and losses of mismatch repair. Primary, colorectal cancers, 13 in HNPCC patients, and 37 sporadic tumors (17 with mutator phenotypes) were examined for telomerase activity by the TRAP (telomeric repeat amplification protocol) assay. The majority of colorectal cancers contained detectable telomerase activity regardless of underlying phenotype (77 percent of HNPCC; 81 percent of sporadic tumors, 88 percent with mutator phenotypes and 75 percent without mutator phenotypes). Therefore, telomerase expression appears to be commonly acquired in the progression of both mutator phenotype and sporadic colorectal cancers.

Inhibitory effects of interleukin 12 on retroviral gene transduction into CD34 cord blood myeloid progenitors mediated by induction of tumor necrosis factor-alpha

Interleukin 12 (IL-12), a heterodimeric cytokine with potent biologic activity, was evaluated for effects on retroviral-mediated gene transduction into human myeloid progenitor cells in vitro. Cord blood CD34 cells were prestimulated with Steel factor (SLF), IL-3, GM-CSF, and erythropoietin (Epo) in the presence and absence of 5-80 ng/ml IL-12 for 40 hr in suspension culture prior to gene transduction using viral supernatant collected from a packaging cell line containing the pLNL6 vector encoding Neo sequences. After gene transduction, cells were assayed for colony formation stimulated by Epo, GM-CSF, IL-3, and SLF, and gene transduction efficiency was determined by the percentage of G418 resistant (R) colonies and confirmed by PCR analysis. IL-12 dose-dependently inhibited retroviral-mediated gene transduction into human cord blood CD34 granulocyte-macrophage (CFU-GM) and erythroid (BFU-E) progenitors. These suppressive effects could be neutralized by incubation of IL-12 with polyclonal antihuman IL-12. IL-12 had no inhibitory effects directly on colony formation. To understand the possible mechanisms for this suppression, ELISA assays were used to detect the release of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha, which could potentially have been induced by IL-12 from CD34 cells. TNF-alpha protein release was significantly increased in CD34 cells incubated with IL-12. No detectable levels of IFN-gamma were noted. Anti-TNF-alpha, but not anti-IFN-gamma, blocked the inhibitory effects of IL-12 on gene transduction. Moreover, TNF-alpha, but not IFN-gamma, suppressed gene transfer to the same degree as IL-12. No change of amphotropic receptor mRNA expression was noted by Northern blot analysis in cells treated with or without IL-12. The results suggest that the suppressive effects of IL-12 on retroviral gene transduction are, at least in part, mediated by IL-12 induction of the release of TNF-alpha.

A novel method for studying preadipocyte differentiation in vitro

In vitro differentiation of rat preadipocytes has typically been induced in medium supplemented with pharmacological concentrations of hormonal mixtures. These conditions probably do not reflect the milieu within adipose tissue in vivo. We have developed a new method for inducing differentiation of preadipocytes using culture medium which has been conditioned by isolated adipocytes (ACM). In the presence of ACM, 70%-80% of test preadipocytes contained lipid inclusions compared to < 5% of control. When differentiation was assessed by assay of glycerol-3-phosphate dehydrogenase activity, ACM activity was shown to be reproducible and the consistency of response to ACM by different pools of preadipocytes was comparable to that induced by standard differentiation procedures. We have also demonstrated that the adipogenic activity of ACM may not depend on prostaglandin secretion by adipocytes. We propose that use of paracrine factors produced by components of adipose tissue provides a new approach to preadipocyte differentiation induction which may more closely reproduce the adipose tissue environment.

Recovery and characterization of CD34+ cord blood cells after cryopreservation

Hematopoietic stem and progenitor cell transplantation is an important therapy for certain hematological and malignant disorders, and these cells are being used as vehicles for potential gene therapy approaches to treatment. Umbilical cord blood is a rich source of stem and progenitor cells, which can be efficiently transduced by viral vectors with new genetic material, and these cells have been used in both allogeneic and autologous transplant settings, the latter setting used by others for gene transfer as a possible means of gene therapy. Since cord blood banking is increasingly being considered as an adjunct for allogeneic and autologous transplantation, the present studies were done in order to evaluate the consequences of cryopreserving highly purified CD34+ cells from cord blood. The results demonstrate that CD34+ cord blood cells can be frozen in cryopreserved form and recovered efficiently with cell cycle, proliferative and cell expansion characteristics equivalent to the pre-freeze samples of cells. This information complements previous studies from our group demonstrating the efficient freezing of relatively unseparated populations of cord blood cells, and should be of practical use for future studies involving banking and use of cord blood stem and progenitor cells.

Effect of probenecid on the distribution, metabolism, and excretion of cidofovir in rabbits

The effect of concomitant probenecid on the tissue distribution, metabolism, and urinary excretion of cidofovir was examined in New Zealand white rabbits. Two groups of six male rabbits received intravenous [3H]cidofovir (5 mg/kg, 20 mu Ci/kg) alone or with concomitant intravenous probenecid (90 mg/kg). Radioactivity in kidney at 15 min postdose was decreased 70% by probenecid; plasma levels at 15 min postdose were increased 65% by probenecid. These effects were diminished at later time points. The estimated elimination half-life of cidofovir from the kidney was 16 hr in the presence of probenecid and 11 hr without probenecid. Two additional groups of six rabbits received intravenous [14C]cidofovir (15 mg/kg, 100 mu Ci/kg) alone or 1 hr after oral administration of probenecid (90 mg/kg). Radioactivity was highest in the kidney (approximately 700 mu g-eq/g at 30 min postdose). Probenecid did not affect the gross distribution of radioactivity. However, autoradiography of left kidneys revealed localization of the drug in the renal cortex; radioactivity in the cortex at 30 min postdose was decreased 50% by probenecid. These data are consistent with inhibition of tubular secretion of cidofovir by probenecid. More than 73% of the cidofovir dose was recovered in the urine in 24 hr. Urine contained unchanged cidofovir (>97%) and a metabolite coeluting with authentic cidofovir phosphocholine (2%). This metabolite also accounted for approximately 1-4% of the radioactivity in rabbit kidney.

Influence of retroviral-mediated gene transduction of both the recombinant human erythropoietin receptor and interleukin-9 receptor genes into single CD34++CD33-or low cord blood cells on cytokine-stimulated erythroid colony formation

Introduction of genes for cytokine receptors into hematopoietic stem/progenitor cells (HSC/HPC) may be of clinical use in the future. We recently reported that retroviral-mediated transduction of either the human erythropoietin receptor (hEpoR) or interleukin-9 receptor (hIL-9R) genes into highly purified HSC/HPC from cord blood (CB) resulted in increased numbers of detectable cytokine-responsive erythroid progenitors (burst-forming units-erythroid [BFU-E]). In the present study, we evaluated if this increase could be further enhanced by cotransducing both these genes into single isolated HSC/HPC. Single CD34++CD33-or low-expressing cells from CB were transduced with viral supernatant containing the hEpoR or hIL-9R genes or cotransduced with both genes. In the presence of Steel factor (SLF), interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), erythropoietin (Epo), and IL-9, the numbers of erythroid colonies formed were significantly increased after transduction of cells with either the hIL-9R or hEpoR gene compared to mock-transduced cells. This increase was significantly enhanced in cells cotransduced with both genes compared with either gene alone. Integration and expression of both genes was confirmed by polymerase chain reaction (PCR) and reverse-transcriptase (RT)-PCR analysis, respectively. The data demonstrate that myeloid progenitors can be transduced at the single-cell level with both hEpoR and hIL-9R genes with resultant enhanced proliferation of these progenitors in the erythroid lineage by combinations of cytokines including Epo and IL-9.