A novel dicyclodextrinyl ditelluride compound with antioxidant activity

Reactive oxygen species (ROS) primarily arise from products of normal metabolic activities and are thought to be the etiology of many diseases. A novel dicyclodextrinyl ditelluride (2-TeCD) compound was designed to be a functional mimic of the glutathione peroxidase that normally removes ROS. 2-TeCD exhibited highly catalytic efficiency and good water solubility. Antioxidant activity was studied by using ferrous sulfate/ascorbate-induced mitochondria damage model system. 2-TeCD protected the mitochondria against oxidative damage in a dose-dependent manner and exhibited also great antioxidant ability in comparison with 2-phenyl-1,2-benziososelenazol-3(2H)-one. The mimic may result in better clinical therapies for the treatment of ROS-mediated diseases.

[Detection of -5/5q- chromosome abnormality in myelodysplastic syndromes by interphase fluorescence in situ hybridization]

OBJECTIVE

To evaluate the value of interphase fluorescence in situ hybridization(FISH) in the detection of acquired complete and partial deletion of chromosome 5(-5/5q-) in myelodysplastic syndromes (MDS).

METHODS

Marrow cells from 48 MDS patients and 10 normal controls were studied by interphase FISH using SpectrumRed directly labelled DNA specific probe for 5q31, 200 to 300 cells were scored for each case and cells with a red hybridization signal > 6% were defined as -5/5q- positive.

RESULTS

In 48 MDS patients, 13 were positive for interphase FISH, of whom, 7 were positive and 6 were negative for conventional cytogenetics (CC). The difference in the percentage of positive cells detected by the two methods was statistically significant (P < 0.05).

CONCLUSION

Interphase FISH is more sensitive than CC for the detection of -5/5q- in MDS.

[Preliminary study on postremission therapy courses in acute myeloid leukemia]

OBJECTIVE

To explore the optimum postremission therapy courses in acute myeloid leukemia (AML).

METHODS

Data from medical records of AML patients in our hospital in 7 year were analyzed with SPSS 8.0 system software.

RESULTS

One hundred and ninety one untreated de novo AML patients received different induction chemotherapy regimens: HA, DA, AA and HAD. The complete remission (CR) rate was 81.4%, 89.9% for one to two courses. The median disease free survival (DFS) in 144 CR patients whose survival time could be analyzed was 9.6 months. The probability of survival was 21.6% at 3 year and 12.9% at 5 year. For the patients received less than 6 courses of post-remission therapy, the median DFS was 7.1 months and the probability of survival was 11.4% at 3 year and 6.3% at 5 years, Whereas for patients received 6 or more courses of post-remission therapy, they were 35.3 months, 43.2% and 27.0%, respectively. The differences between the two groups were statistically significant. For patients received 8 or more courses of post-remission therapy, the median DFS was 48.8 months and the probability of survival was 57.9% at 3 year and 31.6% at 5 year.

CONCLUSION

AML patients should at least receive 6 courses of post-remission therapy, and 8 courses therapy seems better.

Proliferative activity and branching morphogenesis in the human prostate: a closer look at pre- and postnatal prostate growth

BACKGROUND

To gain further insight into the molecular cell biologic features of prostate development, we investigated the proliferative activity of prostate epithelial and stromal cells and their topographic relationship with neuroendocrine (NE) cell distribution and regional heterogeneity.

METHODS

Consecutive sections from 43 prostates taken during autopsy representing fetuses (12-38 weeks of gestation), infants, prepubertal males and adults were double stained for chromogranin A and MIB-1. MIB-1 labeling index (LI) was calculated in the budding tips, forming acini, major collecting ducts, adjacent and non-adjacent stromal compartments. Furthermore, the topographic relationship between proliferating cells and NE cells was evaluated.

RESULTS

In the first half of gestation, cell proliferation as revealed by MIB-1 LI was significantly higher in epithelial structures and stroma than in older fetuses and other age groups. MIB-1 LI was higher in budding tips than in other epithelial regions. MIB-1 LI in stroma adjacent to budding tips was not higher than that adjacent to other epithelial branching segments. Co-expression of chromogranin A and MIB-1 staining was not observed. MIB-1 LI was lower in cells in the direct vicinity of chromogranin A positive NE cells than at a distance from NE cells.

CONCLUSIONS

Prostate development in the first half of gestation is explosive. Thereafter, the prostate basically is a slow-growing organ. Budding tips are the major growth foci during early prostate development, while stromal growth is evenly distributed throughout the prostate, probably indicating that stromal-epithelial interactions do not manifest in enhanced proliferation at their interface. NE cells may have an inhibitory effect on proliferation of exocrine epithelial cells and are probably only associated with differentiation of prostate exocrine cells in the prostate.

Natrialba hulunbeirensis sp. nov. and Natrialba chahannaoensis sp. nov., novel haloalkaliphilic archaea from soda lakes in Inner Mongolia Autonomous Region, China

Two haloalkaliphilic archaeal strains, X21T and C112T, were isolated from soda lakes in Inner Mongolia Autonomous Region, China. Their morphology, physiology, biochemical features, polar lipid composition and 16S rRNA genes were characterized in order to elucidate their taxonomy. According to these data, strains X21T and C112T belong to the genus Natrialba, although there are clear differences with respect to their physiology and polar lipid composition between the two strains and the type species, Natrialba asiatica. On the basis of low DNA-DNA hybridizations, these two strains should be considered as new species of genus Natrialba. The names Natrialba hulunbeirensis sp. nov. (type strain X21T = AS 1.1986T = JCM 10989T) and Natrialba chahannaoensis sp. nov. (type strain C112T = AS 1.1977T = JCM 10990T) are proposed.

Overexpression of manganese superoxide dismutase suppresses tumor formation by modulation of activator protein-1 signaling in a multistage skin carcinogenesis model

Manganese superoxide dismutase (MnSOD) is a nuclear encoded primary antioxidant enzyme localized in mitochondria. Because expression of MnSOD plays a major role in maintaining cellular redox status and reactive oxygen species are known to play a role in signal transduction and carcinogenesis, we investigated the role of MnSOD in the development of cancer using a two-stage [7,12-dimethylbenz(a)-anthracene plus 12-O-tetradecanoylphorbol-13-acetate (TPA)] skin carcinogenesis model. Female transgenic mice expressing the human MnSOD gene in the skin and their nontransgenic counterparts were used in this study. Pathological examination demonstrated significant reduction of papilloma formation in transgenic mice. Quantitative analysis of 4-hydroxy-2-nonenal-modified proteins showed greater accumulation of oxidative damage products in nontransgenic compared with transgenic mice, and this oxidative damage was demonstrated to be present in both mitochondria and nucleus. TPA increased activator protein-1 (AP-1) binding activity within 6 h in nontransgenic mice, but increased AP-1 binding activity was delayed in the transgenic mice. Electrophoretic mobility shift assay, transcription of the target genes, and Western analysis studies indicated that the increased AP-1 binding activity was attributable to induction of the Jun but not the Fos protein families. Overexpression of MnSOD selectively inhibited the TPA-induced activation of protein kinase Cepsilon and prevented subsequent activation of c-Jun NH(2)-terminal kinase in response to TPA. Overall, these results indicate that MnSOD regulates both cellular redox status and selectively modulates PKCepsilon signaling, thereby delaying AP-1 activation and inhibiting tumor promotion, resulting in reduction of tumors in MnSOD transgenic mice.

Kinetics study of a selenium-containing ScFv catalytic antibody that mimics glutathione peroxidase

The steady-state kinetics study and some enzymatic characterization of a selenium-containing scFv catalytic antibody (Se-scFv2F3) were carried out. A novel reaction formula of this abzyme-catalyzed reaction was proposed and a rate equation was obtained according to the formula. The constants in the equation were compared with Dalziel's parameters and the exact meanings of these constants were analyzed. The obtained kinetics parameters from the kinetics study of Se-scFv2F3 were analyzed and compared with those of native glutathione peroxidase.

[Relationship between methylenetetrahydrofolate reductase gene polymorphism and diabetic nephropathy]

OBJECTIVE

To investigate the relationship between methylenetetrahydrofolate reductase(MTHFR) gene polymorphism and diabetic nephropathy(DN).

METHODS

The technology of polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) was used to detect MTHFR gene C677T mutation in 85 healthy controls, 79 type-2 diabetics without DN, and 82 type-2 diabetics with DN confirmed by urine microalbuminous detection.

RESULTS

The frequencies of MTHFR gene variant genotypes and alleles in the patients with DN patients were significantly higher than those in the patients without DN and those in healthy controls (P<0.01).

CONCLUSION

MTHFR gene C677T mutation is probably one of the genetic risk factors for diabetic nephropathy in Chinese Hans.

Sperm protein 17 (Sp17) in multiple myeloma: opportunity for myeloma-specific donor T cell infusion to enhance graft-versus-myeloma effect without increasing graft-versus-host disease risk

We recently found that sperm protein 17 (Sp17), a spermatozoa-restricted protein, is aberrantly expressed on the tumor cells in patients with multiple myeloma (MM). It may therefore be possible to generate donor-derived Sp17-specific CTL for administration following allogeneic stem cell transplant to augment graft-versus-myeloma (GVM) effect without inducing a global GVHD. To assess this approach, we have produced recombinant Sp17 protein and used Sp17 protein-pulsed dendritic cells to generate HLA class I-restricted Sp17-specific CTL from a previously unimmunized healthy donor. These CTL were able to lyse autologous Epstein-Barr virus-transformed lymphoblastoid cells in a Sp17-dependent manner. Target lysis was HLA-A1 and HLA-B27 restricted. Cytotoxicity could be blocked by antibodies against monomorphic HLA class I, HLA-A1 and HLA-B27 molecules but not HLA class II molecules. Most importantly, the CTL lysed HLA class I-matched Sp17-positive tumor cells, suggesting that Sp17 is processed and presented in association with the HLA class I molecules in Sp17-positive tumor cells in a concentration and configuration that could be recognized by recombinant protein-primed CTL. Analysis by flow cytometry of the CTL indicated that they were predominantly CD8 in phenotype and they produced IFN-gamma and very little IL-4. Our results suggest the potential for the generation and administration of donor-derived Sp17-specific CTL to augment GVM without inducing GVHD following allogeneic stem cell transplant for MM.

[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.

[Detection of monosomy 7 or 7q- in cases of myelodysplastic syndrome]

OBJECTIVE

To investigate the value of interphase fluorescence in situ hybridization(FISH) in the detection of monosomy 7 (-7)or deletion of long arm of chromosome 7(7q-) in the cases of myelodysplastic syndrome (MDS).

METHODS

Forty-six cases of MDS and 10 normal controls were studied simultaneously by conventional karyotype analysis and interphase FISH technique using SpectrumRed directly labeled DNA specific probe for 7q32. Two hundred interphase cells were analyzed for each case and the cells with one red hybridization spot<7% were regarded as positive.

RESULTS

Three cases displayed -7/7q- by conventional cytogenetics(CC) and were confirmed by interphase FISH. Six cases in 43 cases who did not show -7/7q- by CC displayed -7/7q- by interphase FISH.

CONCLUSION

Interphase FISH is very useful for the detection of -7 or 7q- in MDS and it is more sensitive than CC.

Kinetics study of a selenium-containing ScFv catalytic antibody that mimics glutathione peroxidase

The steady state kinetic study and some enzymic characterization of a selenium-containing scFv catalytic antibody (Se-scFv2F3) was carried out. A novel reaction formula of this abzyme-catalyzed reaction was proposed and a rate equation was gotten according to the formula. The constants in the equation were compared with Dalziel's parameters and the exact meanings of these constants were analyzed. The gotten kinetics parameters from the kinetics study of Se-scFv2F3 were analyzed and compared with that of native glutathione peroxidase.

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.

Thermoanaerobacter tengcongensis sp. nov., a novel anaerobic, saccharolytic, thermophilic bacterium isolated from a hot spring in Tengcong, China

A new, extremely thermophilic bacterium, designated strain MB4T, was isolated from a Chinese hot spring. The new isolate was an obligately anaerobic, rod-shaped, gram-negative, saccharolytic bacterium. Spore formation was not observed. Growth occurred at temperatures between 50 and 80 degrees C, with an optimum of around 75 degrees C; at pH values between 5.5 and 9.0, with an optimum of 7.0-7.5; and at salinities between 0 and 2.5% NaCl, with an optimum of around 0.2% NaCl. The organism utilized glucose, galactose, maltose, cellobiose, mannose, fructose, lactose, mannitol and starch. Acetate was the main end product from glucose fermentation. Thiosulfate and sulfur were reduced to hydrogen sulfide. Sulfate, sulfite and nitrate were not reduced. Growth was inhibited by hydrogen. The G+C content of the DNA was 33 mol%. Phylogenetic analyses based on the 16S rDNA sequence indicated that the isolate was a new member of the genus Thermoanaerobacter and formed a monophyletic unit within the Thermoanaerobacter cluster. Based on its phenotypic and phylogenetic characteristics, the isolate was proposed as a new species, Thermoanaerobacter tengcongensis. The type strain is MB4T (= Chinese Collection of Microorganisms AS 1.2430T = JCM 11007T).

[Treatment of the pyogenic infection of the thoracolumbar intervertebral space with vascular pedicled rib grafting]

OBJECTIVE

To investigate the effect of vascular pedicled rib grafting in treatment of the pyogenic infection of the thoracolumbar intervertebral space.

METHODS

From November 1993, 7 cases with pyogenic infection of the thoracolumbar intervertebral space were adopted in this study. Among them, there were 5 males and 2 females, aged from 29 to 58 years old. The position of pyogenic infection located at T10 to 11 in 3 cases, at T11 to 12 in 2 cases and at T12 to L1 in 2 cases. During operation, the pyogenic infection was cleared completely and the rib with vascular pedicle was grafted into the intervertebral space.

RESULTS

Followed up for 10 to 60 months, the bone graft unioned in 3 months for 5 patients and unioned in 4 months for 2 patients. There was no recurrence and raised kyphosis.

CONCLUSION

The technique of vascular pedicled rib graft is simple, it can shorten the bone union time and reconstruct the stability of spine.

[The Immunophenotypical features of t (8; 21) (q22; q22) acute myeloid leukemia]

OBJECTIVE

To study the predictive value of immunophenotypical features in t (8; 21) (q22; q22) acute myeloid leukemia (AML).

METHODS

Morphological/cytochemical, flow cytometric immunophenotyping, cytogenetic analyses (MIC) and RT-PCR were performed in 294 previously untreated AML.

RESULTS

(1) In 294 AML patients, t (8; 21) AML were 21.8% (64); in AML-M(2), t (8; 21) AML were 54.7%; and in t (8; 21) AML, AML-M(2) were 81.3%. (2) Compared with control group, CD(19) and CD(34) expressions were higher, and CD(33) expression was lower (P < 0.001) in t (8; 21) AML. (3) If the cut-off value of CD(19) positive was >or= 20%, CD(19) positive rate was 13.6% (40/294) in AML, and 50% (32/64) and 3.5% (8/230) (P < 0.001) in t (8; 21) AML and control group. (4) CD(19)(+) and/or CD(34)(+) t (8; 21) AML accounted for 90.6% (58/64) of t (8; 21) AML and CD(19)(-)/CD(34)(-) for 9.6% (6/64).

CONCLUSION

In t (8; 21) AML, especially M(2)/t (8; 21), CD(19) and CD(34) expressions were high. CD(19) was one of predictive markers of t (8; 21) AML.

[Investigation on the mechanics of adhesion to the selective extracellular matrix coated surfaces of lung cancer cells]

The adhesion properties of tumor cells with extracellular matrix(ECM) are closely associated with their invasion and metastasis. Our work reported here was intended reveal the relevant biomechanical and biorheological manifestations of human lung cancer. Using micropipette aspiration technique, we investigated quantitatively the adhesive mechanics properties of high metastatic human giant cell carcinoma(PG) cells as well as low metastatic adenocarcinoma(PAa) cells of lung based on cell culture in vitro. The results showed that the adhesion forces of PAa and PG cells to collagen IV were significantly higher than those to glass surfaces, but at the lower concentrations(1.00 microgram/ml and 2.00 micrograms/ml) of collagen IV, the amplitude for the increase of adhesion forces of PG cells were less than the amplitude for that of PAa cells, and most of the adhesion force values of PAa cells to the coated surfaces of incorporation of laminin along with 2 micrograms/ml collagen IV were significantly greater than those of PG cells. At the lower concentrations(0.625 microgram/ml for PAa cells, and 0.625 microgram/ml, 1.25 micrograms/ml for PG cells) of laminin tested, the adhesion force values of PAa and PG cells all decreased, but the amplitude and level for the decreased values of adhesion forces of PG cells were greater than those for the PAa cells. In conclusion, the adhesive and proteolytic behaviour of cancer cells to extracellular matrix might be mediated mainly by tumor cell membrane receptors such as integrin receptors and laminin receptors, it might affect the biological characteristics and the metastasis of the tumor cells. The results may benefit to explain some questions in biomechanical views about how the highly metastatic PG cells are prone to migration and invasion.

Characterization and analysis of the PikD regulatory factor in the pikromycin biosynthetic pathway of Streptomyces venezuelae

The Streptomyces venezuelae pikD gene from the pikromycin biosynthetic cluster was analyzed, and its deduced product (PikD) was found to have amino acid sequence homology with a small family of bacterial regulatory proteins. Database comparisons revealed two hypothetical domains, including an N-terminal triphosphate-binding domain and a C-terminal helix-turn-helix DNA-binding motif. Analysis of PikD was initiated by deletion of the corresponding gene (pikD) from the chromosome of S. venezuelae, resulting in complete loss of antibiotic production. Complementation by a plasmid carrying pikD restored macrolide biosynthesis, demonstrating that PikD is a positive regulator. Mutations were made in the predicted nucleotide triphosphate-binding domain, confirming the active-site amino acid residues of the Walker A and B motifs. Feeding of macrolide intermediates was carried out to gauge the points of operon control by PikD. Although the pikD mutant strain was unable to convert macrolactones (10-deoxymethynolide and narbonolide) to glycosylated products, macrolide intermediates (YC-17 and narbomycin) were hydroxylated with high efficiency. To study further the control of biosynthesis, presumed promoter regions from pik cluster loci were linked to the xylE reporter and placed in S. venezuelae wild-type and pikD mutant strains. This analysis demonstrated that PikD-mediated transcriptional regulation occurs at promoters controlling expression of pikRII, pikAI, and desI but not those controlling pikRI or pikC.

uPA and uPAR contribute to NK cell invasion through the extracellular matrix

BACKGROUND

The urokinase plasminogen activator (uPA) system has been implicated in cellular invasiveness of tumor cells and immune cells. Herein we provide evidence for the production by natural killer (NK) cells of both uPA and its receptor (uPAR).

MATERIALS AND METHODS

Western blot analysis, RTPCR, casein/plasminogen zymography, and fluorescence microscopy were employed to detect uPA and uPAR on NK cells. NK cell invasiveness was examined using Matrigel invasion assays.

RESULTS

NK cell uPA appeared at its characteristic molecular weights, is enzymatically active in casein/plasminogen zymography, and is recognized by monoclonal antibodies. uPAR was detected by RTPCR and fluorescence microscopy. Matrigel invasion assays demonstrated an active role of uPA in NK cell invasion.

CONCLUSION

The uPA system contributes to extracellular matrix (ECM) degradation by NK cells, which may be essential for NK cell accumulation into metastases, and may be prerequisite for their killing of tumor cells following NK cell adoptive transfer.

Mesodermal patterning defect in mice lacking the Ste20 NCK interacting kinase (NIK)

We have previously shown that the Drosophila Ste20 kinase encoded by misshapen (msn) is an essential gene in Drosophila development. msn function is required to activate the Drosophila c-Jun N-terminal kinase (JNK), basket (Bsk), to promote dorsal closure of the Drosophila embryo. Later in development, msn expression is required in photoreceptors in order for their axons to project normally. A mammalian homolog of msn, the NCK-interacting kinase (NIK) (recently renamed to mitogen-activated protein kinase kinase kinase kinase 4; Map4k4), has been shown to activate JNK and to bind the SH3 domains of the SH2/SH3 adapter NCK. To determine whether NIK also plays an essential role in mammalian development, we created mice deficient in NIK by homologous recombination at the Nik gene. Nik(−/−) mice die postgastrulation between embryonic day (E) 9.5 and E10.5. The most striking phenotype in Nik(−/−) embryos is the failure of mesodermal and endodermal cells that arise from the anterior end of the primitive streak (PS) to migrate to their correct location. As a result Nik(−/−)embryos fail to develop somites or a hindgut and are truncated posteriorly. Interestingly, chimeric analysis demonstrated that NIK has a cell nonautonomous function in stimulating migration of presomitic mesodermal cells away from the PS and a second cell autonomous function in stimulating the differentiation of presomitic mesoderm into dermomyotome. These findings indicate that despite the large number of Ste20 kinases in mammalian cells, members of this family play essential nonredundant function in regulating specific signaling pathways. In addition, these studies provide evidence that the signaling pathways regulated by these kinases are diverse and not limited to the activation of JNK because mesodermal and somite development are not perturbed in JNK1-, and JNK2-deficient mice.

Treponema parvum sp. nov., a small, glucoronic or galacturonic acid-dependent oral spirochaete from lesions of human periodontitis and acute necrotizing ulcerative gingivitis

Small oral spirochaetes with a strict dependence on either glucuronic acid (GluA) or galacturonic acid (GalA) were isolated from European patients with periodontitis and from Chinese patients with either gingivitis or acute necrotizing ulcerative gingivitis (ANUG). Thirteen such isolates were similar phenotypically to Treponema pectinovorum ATCC 33768T and this classification was confirmed by 16S rRNA sequencing. However, four isolates differed from T. pectinovorum by their small cell size, by a prominent beta-glucuronidase activity, by a distinct protein and antigen profile, by an inability to grow on pectin as sole source of carbohydrate and by a markedly enhanced growth rate when supplied with a second carbohydrate (L-arabinose, D-galactose, D-glucose, D-fructose, D-mannitol, D-mannose, pectin, D-ribose or D-xylose) in addition to the essential GluA/GalA. By 16S rRNA sequencing these four isolates clustered in the recently described phylotype 'Smibert-2'. T. pectinovorum (14 strains) and 'Smibert-2' (four isolates with beta-glucuronidase activity) could each be subdivided into two serotypes based on immunoblot reactivity with two mAbs. Representatives of the two groups, including T. pectinovorum ATCC 33768T, showed a 1:2:1-type periplasmic flagellar arrangement. 'Smibert-2' is described as a novel species, Treponema parvum sp. nov., with isolate OMZ 833T (= ATCC 700770T) proposed as the type strain and OMZ 842 (= ATCC 700773) as reference strain for a second serotype.

Chemical modifications of Bacillus subtilis tryptophanyl-tRNA synthetase

A concerted conformational change in Bacillus subtilis tryptophanyl-tRNA synthetase (TrpRS) was evident from previous fluorescence on the quenching of the single Trp residue Trp-92 in the 4FTrp-AMP complexed enzyme. In this study, chemical modifications of the B. subtilis TrpRS were employed to further characterize this conformational change, with the single Trp residue serving as a marker for monitoring the change. Modifications of the enzyme by means of the Trp-specific agent N-bromosuccinimide (NBS) or 3-bromo-3-methyl-2-(2-nitrophenylmercapto)-3H-indole (BNPS-skatole) inactivated the enzyme in accord with the essential role of Trp-92, as identified previously by site-directed mutagenesis. ATP sensitized TrpRS toward inactivation by NBS and BNPS-skatole, which suggested a conformational change that resulted in greater accessibility of Trp-92 toward modifications. In contrast, the cognate tRNATrp substrate exerted a specific protective effect against inactivation by both of the reagents, indicating that the TrpRS-tRNATrp interaction reduces the accessibility of Trp-92 under our experimental conditions. By comparison, modification of sulfhydryl groups by means of iodoacetamide did not reduce TrpRS activity. Observations on Trp-specific modification and substrate protection effects are discussed in the context of the Bacillus stearothermophilus TrpRS crystal structure.

[Association between angiotensin-II receptor gene type I polymorphism and diabetic nephropathy in type 2 diabetes mellitus]

OBJECTIVE

To investigate the relationship between angiotensin type I receptor (AGT I R) gene polymorphism and diabetic nephropathy (DN) and its progression.

METHODS

PCR technique was used to determine the AGT I R gene polymorphism in 86 patients without DN, 67 with microalbuminuria, 66 with clinical albuminuria and 20 type 2 DM patients with renal insufficiency.

RESULTS

In comparing the DN group with the non-DN group, it was found that there was a significant difference of the frequency of AC genotype with DN (chi(2) = 4.30, P < 0.05), and C mutative type was more frequent in the DN group (chi(2) = 3.97, P < 0.05). No significant difference of AGTIR-A1166-C genotype was found in cases with different durations of DN.

CONCLUSION

Delete polymorphism of A1166-C gene is associated with DN in type 2 diabetes mellitus. It is suggested that detection of significant AGTIR-A1166-C polymorphism is of help for preventing DN in type 2 diabetes mellitus.

Sperm protein 17 is a novel cancer-testis antigen in multiple myeloma

Various studies have demonstrated the aberrant expression of normal testicular proteins in neoplastic cells. These proteins collectively form the new class of tumor antigens called cancer-testis (CT) antigens. Their selective normal tissue expression makes them ideal antigens for immune targeting of the malignant disease. In this study, the expression of a spermatozoa protein, Sp17, in multiple myeloma was investigated. It was found that Sp17 is detectable in tumor cells from 12 of 47 (26%) myeloma patients. Reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis detected Sp17 transcripts and proteins, respectively. Northern blot analysis and RT-PCR demonstrated that Sp17 transcripts were detected only in normal testis, supporting its tissue specificity. Since a high proportion of normal individuals develop antibodies against Sp17 following vasectomy, Sp17 is likely to be a highly immunogenic protein in vivo. Sp17 is therefore a novel member of the CT antigen family and should be an ideal target for immunotherapy of multiple myeloma.