Inhibition of human leukemia in an animal model with human antibodies directed against vascular endothelial growth factor receptor 2. Correlation between antibody affinity and biological activity

Vascular endothelial growth factor (VEGF) and its receptors (VEGFR) have been implicated in promoting solid tumor growth and metastasis via stimulating tumor-associated angiogenesis. We recently showed that certain 'liquid' tumors such as leukemia not only produce VEGF, but also express functional VEGFR, resulting in an autocrine loop for tumor growth and propagation. A chimeric anti-VEGFR2 (or kinase insert domain-containing receptor, KDR) antibody, IMC-1C11, was shown to be able to inhibit VEGF-induced proliferation of human leukemia cells in vitro, and to prolong survival of nonobese diabetic-severe combined immune deficient (NOD-SCID) mice inoculated with human leukemia cells. Here we produced two fully human anti-KDR antibodies (IgG1), IMC-2C6 and IMC-1121, from Fab fragments originally isolated from a large antibody phage display library. These antibodies bind specifically to KDR with high affinities: 50 and 200 pM for IMC-1121 and IMC-2C6, respectively, as compared to 270 pM for IMC-1C11. Like IMC-1C11, both human antibodies block VEGF/KDR interaction with an IC(50) of approximately 1 nM, but IMC-1121 is a more potent inhibitor to VEGF-stimulated proliferation of human endothelial cells. These anti-KDR antibodies strongly inhibited VEGF-induced migration of human leukemia cells in vitro, and when administered in vivo, significantly prolonged survival of NOD-SCID mice inoculated with human leukemia cells. It is noteworthy that the mice treated with antibody of the highest affinity, IMC-1121, survived the longest period of time, followed by mice treated with IMC-2C6 and IMC-1C11. Taken together, our data suggest that anti-KDR antibodies may have broad applications in the treatment of both solid tumors and leukemia. It further underscores the efforts to identify antibodies of high affinity for enhanced antiangiogenic and antitumor activities.

Screening of pyruvate-producing yeast and effect of nutritional conditions on pyruvate production

AIMS

To find a yeast strain that can overproduce pyruvate and to investigate the effect of nutrients on pyruvate production.

METHODS AND RESULTS

Trichosporon cutaneum PD70, a yeast strain that can overproduce pyruvate, was isolated from shake-flask cultures of 132 yeast strains. Pyruvate was measured by the HPLC or DNP method (see Materials and methods). Pyruvate production reached approximately 30.0 +/- 1.0 g l(-1) in basal fermentation medium. Different nutrient supplements had great effects on pyruvate production. Some of the conditions that gave the highest yield are described.

CONCLUSIONS

Exogenous thiamine supplement caused a decrease in pyruvate yield. Some amino acids, such as L-arginine, L-isoleucine and L-valine, caused a minor increase in pyruvate yield. Soybean peptone was the most suitable nitrogen source for pyruvate production. A glucose concentration of 15% in fermentation medium gave the highest yield (34.6 g l(-1)) and the highest yield against consumed glucose (0.429 g g(-1)).

SIGNIFICANCE AND IMPACT OF THE STUDY

Nutrients have significant impacts on pyruvate production. As a pyruvate overproducing yeast strain independent of exogenous vitamins or amino acids, T. cutaneum PD70 provides an advantage for commercial pyruvate production.

Adenoviral insulin gene therapy prolongs survival of IDDM model BB rats by improving hyperlipidemia

Diabetes is frequently associated with hyperlipidemia, which results in atherogenic complications. Insulin-dependent diabetes mellitus (IDDM) model BB/Wor//Tky (BB) rats exhibit both hyperglycemia and hyperlipidemia and die within 3 weeks after the onset of diabetes unless insulin therapy is given. We performed insulin gene therapy in BB rats with adenovirus vectors through the tail vein. After infusion, plasma triglyceride levels dropped quickly and maintained low levels for 1 week, whereas blood glucose levels showed a slight decrease. The survival period of diabetic BB rats was prolonged to up to 75 days by infusing insulin gene-expressing adenoviral vectors. We suggest that the control of hyperlipidemia can be a life-saving measure when combined with hyperglycemia control in the treatment of diabetes.

Results of myelography in seven dogs with myelomalacia

Myelomalacia is a hemorrhagic infarction of the spinal cord that can occur as a sequel to acute spinal cord injury. Myelomalacia may be focal or diffuse; the diffuse form is typically associated with cranial migration of neurologic signs ("ascending syndrome") and is often fatal. In a retrospective study of seven affected dogs, diffuse myelomalacia was associated with intervertebral disc extrusion in five dogs, focal myelomalacia was associated with fibrocartilagenous embolus in one dog, and had no apparent cause in one dog. The myelographic signs included a variable degree of contrast medium infiltration into the spinal cord in six dogs (86%) and/or spinal cord swelling in six dogs (86%). In one dog with focal myelomalacia, the only myelographic sign was spinal cord swelling.

The strength of B cell immunity in female rhesus macaques is controlled by CD8+ T cells under the influence of ovarian steroid hormones

To understand more clearly how mucosal and systemic immunity is regulated by ovarian steroid hormones during the menstrual cycle, we evaluated the frequency of immunoglobulin- and antibody-secreting cells (ISC, AbSC) in genital tract and systemic lymphoid tissues of normal cycling female rhesus macaques. The frequency of ISC and AbSC was significantly higher in tissues collected from animals in the periovulatory period of the menstrual cycle than in tissues collected from animals at other stages of the cycle. The observed changes were not due to changes in the relative frequency of lymphocyte subsets and B cells in tissues, as these did not change during the menstrual cycle. In vitro, progesterone had a dose-dependent inhibitory effect, and oestrogen had a dose-dependent stimulatory effect on the frequency of ISC in peripheral blood mononuclear cell (PBMC) cultures. The in vitro effect of progesterone and oestrogen on ISC frequency could not be produced by incubating enriched B cells alone with hormone, but required the presence of CD8+ T cells. Following oestrogen stimulation, a CD8+ enriched cell population expressed high levels of IFN-gamma and IL-12. The changes in B cell Ig secretory activity that we document in the tissues of female rhesus macaques during the menstrual cycle is due apparently to the action of ovarian steroid hormones on CD8+ T cells. Thus, CD8+ T cells control B cell secretory activity in both mucosal and systemic immune compartments. Understanding, and eventually manipulating, the CD8+ regulatory cell-B cell interactions in females may produce novel therapeutic approaches for autoimmune diseases and new vaccine strategies to prevent sexually transmitted diseases.

Acute intervertebral disc extrusion in a cat: clinical and MRI findings

A 5 year old, neutered male, domestic shorthaired cat had acute left hemiparesis and Horner's syndrome. Magnetic resonance imaging (MRI) revealed a loss of the normal signal from the nucleus pulposus of the intervertebral disc at C3/4, narrowing of the ventral subarachnoid space and slight dorsal displacement of the spinal cord and a focal hyperintense lesion affecting the left side of the spinal cord at the same level. The presumptive diagnosis was focal spinal cord oedema associated with intervertebral disc extrusion. A traumatic aetiology was suspected. The cat was treated conservatively and improved gradually over a period of 6 months.

[Successful engraftment of HLA-identical sibling cord blood transplantation in an adult with chronic myelogenous leukemia]

OBJECTIVE

To explore the feasibility of cord blood transplantation (CBT) for the treatment of adult hematological malignancies and its long-term hematopoiesis reconstitution and transplantation-related complications.

METHODS

An 18 years old patient (body weight 75 kg) with chronic myelogenous leukemia in first chronic phase received HLA-identical sibling CBT after conditioning with modified busulfan/cyclophosphamide (Bu/CTX) regimen. The transplanted number of nucleated cells was 1.73 x 10(7)/kg of body weight, and that of CD34+ cells 2. 7 x 10(5)/kg. Cyclosporin A and methylprednisolone were given as prophylaxis against graft versus-host disease (GVHD).

RESULTS

The neutrophil count rose to above 0.5 x 10(9)/L on day 18 and platelet count exceeded 50 x 10(9)/L on day 36. Gene analysis showed that bone marrow cells had completely changed to donor's type on day 80. The patient was diagnosed with grade IV acute hepatic GVHD complicated with CMV infection because of severe jaundice on day 90. After the administration of additional immunosuppressive agents, antiviral agents, plasma exchange and in vitro billirubin adsorption, the complications were well controlled. In the follow-up of 24 months', the patient's general condition is good without obvious hepatic dysfunction and Ph chromosome and bcr/abl fusion gene of bone marrow cells were persistently negative.

CONCLUSION

It is the first case reported in China that adult patient with leukemia has been successfully treated by allogeneic CBT, and this indicates that CBT is feasible in the treatment of adult patient with leukemia.

[The transfer and expression of human clotting factor IX in muscle mediated by electroporation]

OBJECTIVE

To probe into the feasibility of increasing hFIX cDNA transfer and expression in muscle.

METHODS

The high-frequency electric field was used to promote both Lac-Z-encoding plasmid pCMV beta and hFIX-expressing plasmid G1NaMCIX to transfer and express in muscle. The effects of frequency and length of square pulse, as well as eletroporation time on hFIX expression were investigated.

RESULTS

Electric stimulation could increase the transfer and expression of pCMV beta in muscle, the number of X-gal positive myofiber cells in electroporation-treated mice is 2.1 times larger than that of mice not treated by electroporation (P<0.01). The most optimal electric simulation condition for hFIX cDNA transfer and expression was obtained, under this condition, the highest level of hFIX antigen in plasma is (40+/- 5.4) ng/ml and 7 times higher than that of mice without electroporation P < 0.001).

CONCLUSION

Electroporation is able to enhance hFIX cDNA transfer and expression in muscle efficiently.

Low power density microwave radiation induced early changes in rabbit lens epithelial cells

OBJECTIVE

To determine whether low power density microwave radiation can induce irreversible changes in rabbit lens epithelial cells (LECs) and the mechanisms of the changes.

METHODS

One eye of each rabbit was exposed to 5 mW/cm2 or 10 mW/cm2 power density microwaves for 3 hours, while the contralateral eye served as a control. Annexin V-propidium iodide (PI) two-color flow cytometry (FCM) was used to detect the early changes in rabbit lens epithelial cells after radiation.

RESULTS

Lots of rabbit LECs were in the initial phase of apoptosis in the 5 mW/cm2 microwave radiation group. A large number of cells became secondary necrotic cells, and severe damage could be found in the group exposed to 10 mW/cm2 microwave radiation.

CONCLUSION

Low power densities of microwave radiation (5 mW/cm2 and 10 mW/cm2) can induce irreversible damage to rabbit LECs. This may be the non-thermal effect of microwave radiation.

Treatment of traumatic brain injury in female rats with intravenous administration of bone marrow stromal cells

OBJECTIVE

To study the effect of bone marrow stromal cells administered intravenously to female rats subjected to traumatic brain injury.

METHODS

We injected marrow stromal cells harvested from male rat bone marrow (n = 24) into the tail vein of the female rat (n = 8) 24 hours after traumatic brain injury; the rats were killed at Day 7 or 14 after treatment. The neurological function of the rats was evaluated using the rotarod test and the neurological severity score. The distribution of the male donor cells in brain, heart, lung, kidney, liver, muscle, spleen, and bone marrow of the female recipient rats was measured by identifying Y chromosome-positive cells using fluorescent in situ hybridization.

RESULTS

We found that marrow stromal cells injected intravenously significantly reduced motor and neurological deficits compared with control groups by Day 15 after traumatic brain injury (P < 0.05, analysis of covariance for repeated measures). The transplanted cells preferentially engrafted into the parenchyma of the injured brain and expressed the neuronal marker NeuN and the astrocytic marker glial fibrillary acidic protein. Marrow stromal cells were also found in other organs in female rats subjected to traumatic brain injury without any obvious adverse effects.

CONCLUSION

These data suggest that the intravenous administration of marrow stromal cells may be a promising therapeutic strategy that warrants further investigation for patients with traumatic brain injury.

Single crystal particles of a mesoporous mixed transition metal oxide with a wormhole structure

A new type of mesoporous mixed transition metal oxide of Nb and Ta (NbTa-TIT-1) has been prepared through a two-step calcination, which consists of single crystal particles with wormhole mesoporous structure.

Titration of an SIVmac251 stock by vaginal inoculation of Indian and Chinese origin rhesus macaques: transmission efficiency, viral loads, and antibody responses

The purpose of this study was to determine whether rhesus monkeys of Chinese origin are suitable for studies of mucosal lentivirus transmission by comparing the relative ability of these animals and rhesus macaques of Indian origin to become infected by vaginal (IVAG) inoculation with SIVmac251. In addition, we sought to test the hypothesis that differences in viral load during the first few weeks after inoculation were due to the relative strength of the anti-SIV immune responses in the two populations of rhesus macaques. Significant difference was not observed between the number of Indian and Chinese origin monkeys that were infected after IVAG SIV inoculation in this study. For 8-9 weeks after infection there was considerable overlap in the range of viral loads among the Indian and Chinese animals and the variation among the Indian origin animals was greater than the variation among the Chinese origin monkeys. By 6 weeks postinfection, viral loads in SIV-infected Chinese origin monkeys tended to be at the lower end of the range of viral loads observed in SIV-infected Indian origin monkeys. The strength of the anti-SIV antibody response was also more variable in the Indian origin rhesus macaques, but at 6-8 weeks postinfection, Chinese and Indian origin rhesus macaques had similar titers of anti-SIV antibodies. Microsatellite allele frequencies differed between Chinese and Indian rhesus macaques; however, the majority of alleles present in Indian-origin animals were also found in Chinese macaques. Together these results show that host factors, other than geographic origin, determine the ability of a rhesus macaque to be infected after IVAG SIV exposure and that geographic origin does not predict the viral load of SIV-infected animals during the first 8-9 weeks after IVAG inoculation.

The cAMP-mediated protein kinase signal transduction pathway is involved in the pyrogenic effect of CRH in rats

OBJECTIVE

To determine whether the cyclic adenosine monophosphate (cAMP) mediated protein kinase signal transduction pathway is involved in the pyrogenic action of corticotropin releasing hormone (CRH) in rats.

METHODS

Corticotropin releasing hormone, 2',3'-dideoxyadenosine (DDA) and adenosine-3',5'-(cyclic) monophosphorothionate, Rp-Isomer (Rp-cAMPS), were administered intracerebroventricularly (i.c.v.). The colonic temperature was measured using a thermistor, and the content of cAMP in the hypothalamus was determined by radioimmunoassay. Hypothalamic incubation was used to assess the effects of CRH on the content of cAMP in the hypothalamus in vitro.

RESULTS

Microinjection (i.c.v.) of CRH (2.5 micrograms, 5.0 micrograms and 10 micrograms) caused increases in colonic temperature and the hypothalamus cAMP level in conscious rats. CRH increased hypothalamus cAMP level in vitro. The pyrogenic effects of CRH were abolished or markedly inhibited by prior injection (i.c.v.) of an adenylate cyclase inhibitor, DDA (30 micrograms), or an inhibitor of cAMP-dependent protein kinase, Rp-cAMPS (15 micrograms).

CONCLUSION

cAMP mediates the pyrogenic action of centrally administered of CRH in rats, and protein kinase A may play an important role in the central CRH-induced fever. The cAMP-dependent protein kinase signal transduction pathway may be involved in the central mechanisms of the pyrogenic action of CRH in rats.

Complete inhibition of vascular endothelial growth factor (VEGF) activities with a bifunctional diabody directed against both VEGF kinase receptors, fms-like tyrosine kinase receptor and kinase insert domain-containing receptor

Vascular endothelial growth factor (VEGF) binds to and mediates its activity mainly through two tyrosine kinase receptors, VEGF receptor 1 [or fms-like tyrosine kinase receptor (Flt-1)] and VEGF receptor 2 [or kinase insert domain-containing receptor (KDR)]. Numerous studies have shown that overexpression of VEGF and its receptor plays an important role in tumor-associated angiogenesis and hence in both tumor growth and metastasis. We demonstrated previously that antagonistic antibodies to KDR specifically inhibited VEGF-stimulated receptor activation, cell migration, and endothelial cell mitogenesis. Here we constructed a recombinant bifunctional diabody that is capable of blocking both Flt-1 and KDR from binding to their ligands, including VEGF and placenta growth factor (PlGF). The diabody was expressed in Escherichia coli and purified by single-step affinity chromatography. The diabody retained the capacity to bind both KDR and Flt-1 and effectively blocked interaction between KDR and VEGF, Flt-1 and VEGF, and Flt-1 and PlGF. Furthermore, the diabody is a stronger inhibitor than its parent antibodies to VEGF-stimulated mitogenesis of human endothelial cells, as well as both VEGF- and PlGF-induced migration of human leukemia cells. Taken together, our results suggest that dual receptor blockade with the bifunctional diabody may prove to be a more efficient approach in inhibiting VEGF-stimulated angiogenesis.

Transcriptional regulation of the estrogen-inducible pS2 breast cancer marker gene by the ERR family of orphan nuclear receptors

The estrogen-receptor-related receptors (ERRs) alpha, beta, and gamma are orphan nuclear hormone receptors that share significant homology with the estrogen receptors (ERs) but are not activated by natural estrogens. In contrast, the ERRs display constitutive transcriptional activity in the absence of exogenously added ligand. However, the ERRs bind to the estrogen response element and to the extended half-sites of which a subset can also be recognized by ERalpha, suggesting that ERRs and ERs may control overlapping regulatory pathways. To test this hypothesis, we explored the possibility that ERRs could regulate the expression of the estrogen-inducible pS2 gene, a human breast cancer prognostic marker. Transfection studies show that all of the ERR isoforms can activate the pS2 promoter in a variety of cell types, including breast cancer cell lines. Surprisingly, sequence analysis combined with mutational studies revealed that, in addition to the well-characterized estrogen response element, the presence of a functional extended half-site within the pS2 promoter is also required for complete response to both ER and ERR pathways. We show that ERR transcriptional activity on the pS2 promoter is considerably enhanced in the presence of all three members of the steroid receptor coactivator family but is completely abolished on treatment with the synthetic estrogen diethylstilbestrol, a recently described inhibitor of ERR function. Finally, we demonstrate that ERRalpha is the major isoform expressed in human breast cancer cell lines and that diethylstilbestrol can inhibit the growth of both ER-positive and -negative cell lines. Taken together, these results demonstrate that estrogen-inducible genes such as pS2 can be ERR targets and suggest that pharmacological modulation of ERRalpha activity may have therapeutic value in the treatment of breast cancer.

Identified circadian rhythm genes of ciliary epithelium with differential display

PURPOSE

To identify differential genes expressed in the rabbit ciliary epithelium during the circadian cycle of aqueous flow.

METHODS

Total RNA from ciliary epithelium of rabbits at 8 AM (light on 1 hour) and 8 PM (light off 1 hour) were compared by differential display reverse transcription-polymerase chain reaction (DD RT-PCR), using 6% denaturing polyacrylamide electrophoresis, choose differential display bands, cut and reamplify with the same primer, clone and sequence. Search the database of Genbank, prolong them with 5' RACE and 3' RACE technique then clone, sequence and search database of Genbank.

RESULTS

93 Significant differences gene expression were detected between light on and light off in the rabbit ciliary epithelium.

CONCLUSION

Differential display is a powerful tool to screen differentially expressed genes in circadian rhythm of ciliary epithelium.

[A simple and rapid new method for SNP typing by single-tube bi-directional allele specific amplification]

OBJECTIVE

To establish a new method for single nucleotide polymorphism(SNP) typing based on allele specific PCR: single-tube bi-directional amplification (SB-ASA), and study the influence on specific extension by introducing a mismatch at the third 3'terminal base of allele specific primers.

METHODS

Two allele specific primers, with a mismatch introduced at the third 3'terminal base, were both included in PCR system; they extended in opposite directions and amplified two allele specific fragments different in size. The genotype was determined by observing the length of amplified fragments after agarose electrophoresis. The proper ranges of annealing temperature (Ta) under which primers can specifically extend were achieved by observing the amplification status at different temperatures.

RESULTS

SB-ASA was successfully used to type 36 samples for four different kinds of SNPs. Typing results were completely consistent with those by directional sequencing. Proper Ta ranges of two primers were expanded respectively from 64-69 degrees centigrade to 46-66 degrees centigrade and from 60-62 degrees centigrade to 56-61 degrees centigrade by introducing a mismatch at the third 3'terminal base.

CONCLUSION

SB-ASA is a simple, rapid and efficient new method for SNP typing. During allele specific PCR reaction, specific primers with a mismatch at the third 3'terminal base have more power to identify two alleles.

A novel isoform of beta-spectrin II localizes to cerebellar Purkinje-cell bodies and interacts with neurofibromatosis type 2 gene product schwannomin

We report the identification of a full-length novel beta-spectrin II gene (betaSpIIsigma2) in human brain. The betaSpIIsigma2 gene has 32 exons encoding an actin-binding domain, followed by 17-spectrin repeats, and a short COOH-terminal regulatory region that lacks the Pleckstrin homology (PH) domain. Pair-wise sequence analysis showed an additional 36 and 28 amino acids located at the NH2 and COOH-terminal regions of betaSpIIsigma2, respectively. Northern-blot analysis showed an abundant expression of betaSpIIsigma2 transcripts in brain, lung, and kidney. Western-blot analysis confirmed the predicted approximately 225 kD molecular size of betaSpIIsigma2 protein in these same tissues. In brain, immunofluorescent staining revealed that betaSpIIsigma2 was enriched in cerebellar neurons, with specific enrichment in Purkinje cell bodies, but not in dendrites. Of considerable interest, neurofibromatosis type 2 (NF2) gene product schwannomin was found to co-immunoprecipitate with betaSpIIsigma2 in cultured Purkinje cells. These results suggest that betaSpIIsigma2 may play an important role in the assembly of the specialized plasma membrane domain of Purkinje neurons and that schwannomin may be involved in actin-cytoskeleton organization by interacting with betaSpIIsigma2.

Intraarterial administration of marrow stromal cells in a rat model of traumatic brain injury

To test the efficacy of various delivery routes of stem cells to treat cerebral injury, we investigated the parenchymal distribution of marrow stromal cells (MSCs) injected into the internal carotid artery (ICA) of the adult rat after traumatic brain injury (TBI). Bromodeoxyuridine (BrdU)-labeled MSCs were injected via the ipsilateral ICA at 24 h after TBI. Using histology and immunohistochemistry, the distribution of implanted MSCs was analyzed at 7 days after transplantation. Four groups (n = 4/group) were studied: group 1, animals transplanted with MSCs cultured with NGF and BDNF at 24 h after TBI; group 2, animals transplanted with MSCs cultured without NGF and BDNF; group 3, animals injected with a placebo, phosphate buffered saline into the ICA at 24 h after TBI; and group 4, rats subjected to TBI only. In groups 1 and 2, BrdU-positive cells were localized to the boundary zone of the lesion, corpus callosum and cortex of the ipsilateral hemisphere. The number of BrdU-positive cells was significantly higher in the ipsilateral hemisphere than in the contralateral hemisphere. More MSCs infused intraarterially engrafted in group 1 (18.9%) than in group 2 (14.4%, p < 0.05). Using double staining, BrdU-positive cells expressed MAP-2, NeuN, and GFAP in both groups 1 and 2, with this expression being greater in group 1 and the difference between two groups reaching statistical significance in case of MAP-2. Our data suggest that intraarterial transplantation of MSCs is a viable route for the intracerebral administration of MSCs for the treatment of TBI, since MSCs infused intraarterially after TBI survive and migrate into the brain. Some implanted MSCs express proteins specific to neurons and astrocytes. The addition of NGF and BDNF promote migration of MSCs into the brain and subsequent expression of neuronal protein MAP-2.

Protection against simian immunodeficiency virus vaginal challenge by using Sabin poliovirus vectors

Here we provide the first report of protection against a vaginal challenge with a highly virulent simian immunodeficiency virus (SIV) by using a vaccine vector. New poliovirus vectors based on Sabin 1 and 2 vaccine strain viruses were constructed, and these vectors were used to generate a series of new viruses containing SIV gag, pol, env, nef, and tat in overlapping fragments. Two cocktails of 20 transgenic polioviruses (SabRV1-SIV and SabRV2-SIV) were inoculated into seven cynomolgus macaques. All monkeys produced substantial anti-SIV serum and mucosal antibody responses. SIV-specific cytotoxic T-lymphocyte responses were detected in three of seven monkeys after vaccination. All 7 vaccinated macaques, as well as 12 control macaques, were challenged vaginally with pathogenic SIVmac251. Strikingly, four of the seven vaccinated animals exhibited substantial protection against the vaginal SIV challenge. All 12 control monkeys became SIV positive. In two of the seven SabRV-SIV-vaccinated monkeys we found no virological evidence of infection following challenge, indicating that these two monkeys were completely protected. Two additional SabRV-SIV-vaccinated monkeys exhibited a pronounced reduction in postacute viremia to <10(3) copies/ml, suggesting that the vaccine elicited an effective cellular immune response. Three of six control animals developed clinical AIDS by 48 weeks postchallenge. In contrast, all seven vaccinated monkeys remained healthy as judged by all clinical parameters. These results demonstrate the efficacy of SabRV as a potential human vaccine vector, and they show that the use of a vaccine vector cocktail expressing an array of defined antigenic sequences can be an effective vaccination strategy in an outbred population.

[Cytogenetic analysis on 1058 cases of acute nonlymphocytic leukemia]

OBJECTIVE

To evaluate the karyotypic status in a large series of acute nonlymphocytic leukemia(ANLL) cases.

METHODS

A total of 1058 cases of de novo ANLL were studied. Chromosome preparations were made on bone marrow cells using direct method and short-term culture. Karyotypes were analyzed by R-banding in all cases and G-banding in some cases in addition.

RESULTS

Six hundred and thirty cases (60%) had clonal chromosomal abnormalities. 25 categories of major karyotypic abnormalities were found. Among them, 11 were the specific chromosomal rearrangements seen in 481 cases, accounting for 76% of the total number of patients with karyotypic abnormalities. Isolate trisomy 8 (21 cases) was the most common numerical abnormality. t(15;17)(211 cases) and t(8;21)(200 cases) were the most frequent structural abnormalities. The 1.1% of M(2), 72% of M(3), 71% of M(4E0), 50% of M(2), 6 % of M(5) and 1.4% of M(2) had t(7;11), t(15;17), inv(16), t(8;21), t/del(11q 23) and t/del(12p) abnormalities, however, the 100% of t(7;11), 100% of t(15;17 ), 100% of inv(16), 88.5% of t(8;21), 83% of t/del(11q23) and 62% of t/del(12p) were detected in patients with M(2), M(3), M(4E0), M(2), M(5) and M(2) subtypes, respectively.

CONCLUSION

By conventional banding technique, including R- and G-bandings, 60% of patients with ANLL may be found to have clonal chromosomal abnormalities which are predominantly specific chromosomal rearrangements correlated with specific FAB subtypes. Thus, karyotype is an important indicator for diagnosis and classification of ANLL.

t(8;21;8)(p23;q22;q22): a new variant form of t(8;21) translocation in acute myeloblastic leukemia with maturation

The complex variants of t(8;21) involving chromosomes 8 and 21 as well as a variable chromosome account for 1.1-5% of acute myeloid leukemia (AML) patients. This paper reports a case of AML-M2 with t(8;21;8) translocation for the first time. The patient was a female, aged 47 years. Her myelogram was compatible with AML-M2. Chromosome study using R-banding technique revealed a karyotype 46, XX, t(8;8)(p23;q22). Dual-color FISH assay with two probes P1 164(green signal) and YAC 225B8 (red signal) both of which closely located on the 8q showed that one yellow signal consisting of a green signal and a red signal and one red signal appeared on the long and the short arm of the same der(8) chromosome, respectively, further confirming this translocation occurred between both homologous chromosomes 8. RT-PCR analysis detected the AML1/ETO fusion transcript in our patient, thus indicating that this chromosomal aberration was, in fact, a complex three-way rearrangement t(8;21;8)(p23;q22;q22). In conclusion, combining conventional karyotype, FISH or RT-PCR analyses is a rational strategy for identification of the complex variants of t(8;21) translocation.

A polymorphism in the promoter region of catalase is associated with blood pressure levels

Catalase is an important antioxidant enzyme that detoxifies H2O2 into oxygen and water and thus limits the deleterious effects of reactive oxygen species (ROS). Because chronic exposure to excess ROS may contribute to vascular damage, we investigated whether genetic variation in catalase was associated with susceptibility to essential hypertension (EHYT) in 324 individuals (at least 50 years old) who were randomly sampled from an isolated population living in Xiangchang, China. They were screened for genetic variation in the promoter of catalase by direct sequencing. In total, four single nucleotide polymorphisms (SNPs) were identified. The association between the SNPs and EHYT was investigated by a linear regression model under phenotypic selection; in our analyses, we used both SBP>150 mmHg and SBP>160 mmHg as thresholds. A SNP 844 bp upstream of the start codon (SNP-844) demonstrated strong evidence of association with EHYT (SBP>150 mmHg: F=5.09, P=0.008; SBP>160 mmHg: F=7.13, P=0.002). This is the first study to implicate genetic variation in catalase in susceptibility to EHYT and suggests that polymorphisms in promoter regions may be particularly relevant to the study of complex diseases.

Skin reflectance in the Han Chinese and Tibetan populations

Genetic and environmental factors are involved in the determination of skin pigmentation in humans. With the recent development of statistical and genetic tools in mapping complex traits in humans, it is becoming feasible to utilize such methods in identifying genes involved in skin pigmentation. Furthermore, the use of new portable reflectance spectroscopy instruments such as the Photovolt ColorWalk colorimeter allows researchers to measure skin reflectance of a large number of subjects with ease and accuracy. We used a new portable instrument (Photovolt ColorWalk) to study the skin reflectance of 372 Han Chinese and 274 Tibetan individuals to establish background reflectance measurements of unexposed skin of the inner upper arm in these two populations. In addition, we explored the effect of various factors such as age and gender on skin reflectance.

[Cloning and expression of VHB gene in D-arabitol producing yeast]

Recombinant plasmid pVgb-EX2 containing Vitreoscilla hemoglobin gene vgb and formaldehyde resistant gene SFA1 was constructed and transformed into D-arabitol producing yeast strain Saccharomyces sp. X-62. The fact that the amount of VHb in transformant cells was considerably higher than that in control cells indicated that gene vgb was expressed in transformant cells. D-arabitol productivity and yield of fermentation by transformants were improved. The most improvement of D-arabitol productivity in repeat experiments reached 27.3%. It appeared that the fermentation productivity of D-arabitol was relative to the amount of VHb in cells under experimental conditions.