Accumulation of lead, zinc, copper and cadmium by 12 wetland plant species thriving in metal-contaminated sites in China

The concentrations of lead, zinc, copper and cadmium accumulated by 12 emergent-rooted wetland plant species including different populations of Leersia hexandra, Juncus effusus and Equisetum ramosisti were investigated in field conditions of China. The results showed that metal accumulation by wetland plants differed among species, populations and tissues. Populations grown in substrata with elevated metals contained significantly higher metals in plants. Metals accumulated by wetland plants were mostly distributed in root tissues, suggesting that an exclusion strategy for metal tolerance widely exists in them. That some species/populations could accumulate relatively high metal concentrations (far above the toxic concentration to plants) in their shoots indicates that internal detoxification metal tolerance mechanism(s) are also included. The factors affecting metal accumulation by wetland plants include metal concentrations, pH, and nutrient status in substrata. Mostly concentrations of Pb and Cu in both aboveground and underground tissues of the plants were significantly positively related to their total and/or DTPA-extractable fractions in substrata while negatively to soil N and P, respectively. The potential use of these wetland plants in phytoremediation is also discussed.

Confirmation and refinement of a genetic locus for disseminated superficial actinic porokeratosis (DSAP1) at 12q23.2-24.1

BACKGROUND

Our previous study has identified two loci for disseminated superficial actinic porokeratosis (DSAP), but the genes responsible are still unknown.

OBJECTIVES

To narrow down the candidate regions and to assess candidate genes.

METHODS

A genome-wide scan and linkage analysis were carried out in a newly collected five-generation Chinese family with DSAP. In addition, six candidate genes were screened for possible DSAP-associated mutations.

RESULTS

DSAP in this family was associated with chromosome 12q. Fine mapping and haplotype construction refined the DSAP1 locus to a 4.4-cM interval. No disease-associated mutation was detected in CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 or KIAA0789 genes.

CONCLUSIONS

The DSAP1 locus was localized to a 4.4-cM interval at chromosome 12q23.2-24.1. CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 and KIAA0789 genes were not associated with DSAP1.

Measurement of the negative muon anomalous magnetic moment to 0.7 ppm

The anomalous magnetic moment of the negative muon has been measured to a precision of 0.7 ppm (ppm) at the Brookhaven Alternating Gradient Synchrotron. This result is based on data collected in 2001, and is over an order of magnitude more precise than the previous measurement for the negative muon. The result a(mu(-))=11 659 214(8)(3) x 10(-10) (0.7 ppm), where the first uncertainty is statistical and the second is systematic, is consistent with previous measurements of the anomaly for the positive and the negative muon. The average of the measurements of the muon anomaly is a(mu)(exp)=11 659 208(6) x 10(-10) (0.5 ppm).

ALFRED: the ALelle FREquency Database. Update

Elaboration of ALFRED (http://alfred.med.yale.edu) is being continued in two directions. One of which is developing tools for efficiently annotating the entries and checking the integrity of the data already in the database while the other is to increase the quantity and accessibility of data. Information contained in ALFRED such as, polymorphic sites, number of populations and frequency tables (one sample typed for one site) has significantly increased.

A novel locus (DSAP2) for disseminated superficial actinic porokeratosis maps to chromosome 15q25.1-26.1

BACKGROUND

Disseminated superficial actinic porokeratosis (DSAP) is a chronic cutaneous disorder characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. It develops in teenagers in sun-exposed areas of skin and usually follows an autosomal dominant inheritance pattern. The first locus for DSAP was localized to chromosome 12q23.2-24.1, but no gene responsible for porokeratosis has been identified to date.

OBJECTIVES

To determine whether DSAP is a genetically heterogeneous disorder and to identify the disease gene locus in a three-generation Chinese family with DSAP.

METHODS

Genetic linkage analysis was carried out in this family using 15 microsatellite markers between D12S1671 and D12S369 on chromosome 12q, followed by a genome-wide scan with 382 microsatellite markers from the autosomes.

RESULTS

Genetic linkage analysis with chromosome 12q markers suggested that the locus in this family is not linked to chromosome 12q. A genome-wide scan and fine mapping finally localized the locus for DSAP in this family to a 6.4-cM region between markers D15S1023 and D15S1030 at chromosome 15q25.1-26.1. This DSAP locus was named DSAP2.

CONCLUSIONS

The previous results and this study have shown that DSAP is a genetically heterogeneous disorder; a novel locus for DSAP, termed DSAP2, was mapped to a 6.4-cM region between markers D15S1023 and D15S1030.

Measurement of the positive muon anomalous magnetic moment to 0.7 ppm

A higher precision measurement of the anomalous g value, a(mu)=(g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron, based on data collected in the year 2000. The result a(mu(+))=11 659 204(7)(5)x10(-10) (0.7 ppm) is in good agreement with previous measurements and has an error about one-half that of the combined previous data. The present world average experimental value is a(mu)(expt)=11 659 203(8)x10(-10) (0.7 ppm).

Production of duck-chicken chimeras by transferring early blastodermal cells

Duck blastodermal cells isolated from Stage X embryos of Maya ducks were injected into subgerminal cavity of recipient Stage X chicken embryos treated with gamma-irradiation or untreated. Eleven somatic chimeras were obtained based on plumage color and were raised to sexual maturity. To test for germline chimerism, progeny tests were performed by mating the chimeras with Maya ducks. A total of 622 eggs was collected and incubated. Fertility rate and hatchability were 2.9% (18/622) and 1.0% (6/622), respectively. The six duck hatchlings were from Chimera 9801 and were considered to be derived from the germ cells developed from the donor Maya blastodermal cells, indicating that Chimera 9801 is a germline chimera.

A gene therapy for cancer based on the angiogenesis inhibitor, vasostatin

The growth and persistence of solid tumors and their metastasis are angiogenesis-dependent. Vasostatin, the N-terminal domain of calreticulin inclusive of amino acids 1-180, is a potent angiogenesis inhibitor. To investigate whether intramuscular administration of vasostatin gene has the antitumor activity in mouse tumor models, we constructed a plasmid DNA encoding vasostatin and a control vector. Production and secretion of vasostatin protein by COS cells transfected with the plasmid DNA encoding vasostatin (pSecTag2B-vaso) were confirmed by Western blot analysis and ELISA. Conditioned medium from vasostatin-transfected COS cells apparently inhibited human umbilical vein endothelial cell (HUVEC) and mouse endothelial cell (SVEC4-10) proliferation, compared with conditioned medium from the COS cells transfected with control vector or non-transfected cells. Treatment with pSecTag2B-vaso twice weekly for 4 weeks resulted in the inhibition of tumor growth and the prolongation of the survival of tumor-bearing mice. The sustained high level of vasostatin protein in serum could be identified in ELISA. Angiogenesis was apparently inhibited in tumor by immunohistochemical analysis. Angiogenesis was also inhibited in the chicken embryo CAM assay and mouse corneal micropocket assay. The increased apoptotic cells were found within the tumor tissues from the mice treated with plasmid DNA encoding vasostatin. Taken together, the data in the present study indicate that the cancer gene therapy by the intramuscular delivery of plasmid DNA encoding vasostatin, is effective in the inhibition of the systemic angiogenesis and tumor growth in murine models. The present findings also provide further evidence of the anti-tumor effects of the vasostatin, and may be of importance for the further exploration of the application of this molecule in the treatment of cancer.

[Roles of sex hormones and oxygen free radical in coronary heart disease]

To examine the roles of sex hormones and oxygen free radical(OFR) in coronary heart disease (CHD), the serum estradiol(E2), testosterone(T), SOD, MDA and lipid levels were measured in 44 postmenopausal women with CHD and 22 health women. Mean levels of T and MDA were significantly higher while mean levels of SOD and E2 were significantly lower in CHD group than those in control group. On relative analysis, there was a positive correlation between E2 and SOD, while a negative correlation was observed between T and MDA in CHD group. Eighteen postmenopausal women with CHD had been receiving nilestriol replacement therapy for 12 weeks. The serum SOD and HDL-C/TC levels increased significantly, but LDL-C and MDA decreased significantly. The overall data suggest that OFR plays an important role in CHD; Low E2 levels is a risk factor of CHD in postmenopausal women; Nilestriol replacement therapy can improve the metabolism of serum lipids and inhibit lipid peroxidation, therefore, it may be of benefit to postmenopausal women with CHD.

Evidence for a major gene for bone mineral density/content in human pedigrees identified via probands with extreme bone mineral density

Bone mineral content (BMC) and/or bone mineral density (BMD, i.e. BMC scaled by bone size) are major determinants for osteoporosis, which is a serious health problem. The major determinant of variation in BMD/BMC is genetic. The few studies now available are inconsistent in the identification and/or even in the existence of major gene(s) for BMD/BMC. In 51 human pedigrees with 941 individuals (526 measured for phenotypes) identified via probands with extreme BMD values, we performed complex segregation analyses to test the existence of a genetic locus with a major effect on BMD/BMC variation. We analyzed BMD and BMC at the spine, hip and wrist jointly by employing, as the study phenotype, factor scores (FS) of the principle component that explains approximately 75% of the total BMD/BMC variation at the three sites. The results indicate that a major gene exists with a codominant effect that is responsible for approximately 16% of the FS variation when adjusted for significant effects of sex, body weight and age. A significant genotype-x-sex-x-age interaction was found, which may explain approximately 14% of the FS variation after adjusting for body weight. Testing of various models did not provide support for shared familial environmental effects but suggested the existence of residual polygenic effects, which may explain approximately 50% of the FS variation when adjusting for sex, body weight and age. This study indicates a promising aspect of studies to identify a major gene for BMD/BMC variation in our pedigrees identified via extreme probands.

Anaerobic digestion of olive oil mill effluents together with swine manure in UASB reactors

Combined anaerobic digestion of olive oil mill effluent (OME) with swine manure, was investigated. In batch experiments was shown that for anaerobic degradation of OME alone nitrogen addition was needed. A COD:N ratio in the range of 65:1 to 126:1 was necessary for the optimal degradation process. Furthermore, it was found that methane productions rates during digestion of either swine manure alone or OME alone were much lower than the rates achieved when OME and manure were digested together. Admixing OME with manure at a concentration of 5 to 10% OME resulted in the highest methane production rates. Using upflow anaerobic sludge blanket (UASB) reactors, it was shown that codigestion of OME with swine manure (up to 50% OME) was successful with a COD reduction up to 75%. The process was adapted for degradation of OME with stepwise increase of the OME load to the UASB reactor. The results showed that the high content of ammonia in swine manure, together with content of other nutrients, make it possible to degrade OME without addition of external alkalinity and without addition of external nitrogen source. Anaerobic treatment of OME in UASB reactors resulted in reduction of simple phenolic compounds such as mequinol, phenyl ethyl alcohol and ethyl methyl phenol. After anaerobic treatment the concentration of these compounds was reduced between 75 and 100%. However, the concentration of some degradation products such as methyl phenol and ethyl phenol were detected in significantly higher concentrations after treatment, indicating that the process has to be further optimised to achieve satisfactory removal of all xenobiotic compounds.

Vibrational structure of dihydrofolate bound to R67 dihydrofolate reductase

R67 is a Type II dihydrofolate reductase (DHFR) that catalyzes the reduction of dihydrofolate (DHF) to tetrahydrofolate by facilitating the addition of a proton to N5 of DHF and the transfer of a hydride ion from NADPH to C6. Because this enzyme is a plasmid-encoded DHFR from trimethoprim-resistant bacteria, extensive studies on R67 with various methods have been performed to elucidate its reaction mechanism. Here, Raman difference measurements, conducted on the ternary complex of R67.NADP(+).DHF believed to be an accurate mimic of the productive DHFR.NADPH.DHF complex, show that the pK(a) of N5 in the complex is less than 4. This is in clear contrast to the behavior observed in Escherichia coli DHFR, a substantially more efficient enzyme, where the pK(a) of bound DHF at N5 is increased to 6.5 compared with its solution value of 2.6. A comparison of the ternary complexes in R67 and E. coli DHFRs suggests that enzymic raising of the pK(a) at N5 can significantly increase the catalytic efficiency of the hydride transfer step. However, R67 shows that even without such a strategy an effective DHFR can still be designed.

Chemistry of gene silencing: the mechanism of NAD+-dependent deacetylation reactions

The Sir2 enzyme family is responsible for a newly classified chemical reaction, NAD(+)-dependent protein deacetylation. New peptide substrates, the reaction mechanism, and the products of the acetyl transfer to NAD(+) are described for SIR2. The final products of SIR2 reactions are the deacetylated peptide and the 2' and 3' regioisomers of O-acetyl ADP ribose (AADPR), formed through an alpha-1'-acetyl ADP ribose intermediate and intramolecular transesterification reactions (2' --> 3'). The regioisomers, their anomeric forms, the interconversion rates, and the reaction equilibria were characterized by NMR, HPLC, 18O exchange, and MS methods. The mechanism of acetyl transfer to NAD(+) includes (1) ADP ribosylation of the peptide acyl oxygen to form a high-energy O-alkyl amidate intermediate, (2) attack of the 2'-OH group on the amidate to form a 1',2'-acyloxonium species, (3) hydrolysis to 2'-AADPR by the attack of water on the carbonyl carbon, and (4) an SIR2-independent transesterification equilibrating the 2'- and 3'-AADPRs. This mechanism is unprecedented in ADP-ribosyl transferase enzymology. The 2'- and 3'-AADPR products are candidate molecules for SIR2-initiated signaling pathways.

Overexpression of lipoprotein lipase in transgenic rabbits inhibits diet-induced hypercholesterolemia and atherosclerosis

Lipoprotein lipase (LPL) is a key enzyme in the hydrolysis of TG-rich lipoproteins. To elucidate the physiological roles of LPL in lipid and lipoprotein metabolism, we generated transgenic rabbits expressing human LPL. In postheparinized plasma of transgenic rabbits, the human LPL protein levels were about 650 ng/ml, and LPL enzymatic activity was found at levels up to 4-fold greater than that in nontransgenic littermates. Increased LPL activity in transgenic rabbits was associated with as much as an 80% decrease in plasma triglycerides and a 59% decrease in high density lipoprotein-cholesterol. Analysis of the lipoprotein density fractions revealed that increased expression of the LPL transgene resulted in a remarkable reduction in the level of very low density lipoproteins as well as in the level of intermediate density lipoproteins. In addition, LDL cholesterol levels in transgenic rabbits were significantly increased. When transgenic rabbits were fed a cholesterol-rich diet, the development of hypercholesterolemia and aortic atherosclerosis was dramatically suppressed in transgenic rabbits. These results demonstrate that systemically increased LPL activity functions in the metabolism of all classes of lipoproteins, thereby playing a crucial role in plasma triglyceride hydrolysis and lipoprotein conversion, and that overexpression of LPL protects against diet-induced hypercholesterolemia and atherosclerosis.

[Linkage disequilibrium analysis of chromosome 22 and schizophrenia in a Chinese population]

OBJECTIVE

To explore the molecular genetic relations of chromosome 22 and schizophrenia and locate the susceptibility gene of schizophrenia.

METHODS

Six dinucleotide tandem repeat loci on chromosome 22 were chosen to analyze 126 affected sib-pair nuclear families of schizophrenia in Chinese population by fluorescent labeled auto-mated genotyping and transmission/ disequilibrium test(TDT).

RESULTS

The TDT-chi square value of IL2Rbeta was 25.30(P=0.01), which suggests there is linkage disequilibrium between IL2R beta and schizophrenia. The P vaules of the other five loci (D22S944, D22S264, D22S303, D22S278 and CYP2D6) were greater than 0.05.

CONCLUSION

A susceptive gene of schizophrenia may be located in IL2Rbeta locus or adjacent region.

Aryllead(IV) reagents in synthesis: formation of the C11 quaternary center of N-methylwelwitindolinone C isothiocyanate

The reaction of lead(IV) 4-indolyl triacetate with substituted methyl 2-oxo-1-cyclohexanecarboxylates has been investigated as a route to the natural product N-methylwelsitindolinone C isothiocyanate. Reaction of lead(IV) reagent 18 with beta-ketoester 20 affords the desired coupled material in excellent yield and diastereoselectivity. Reaction: see text.

[The measurement of 153Sm-EDTMP bone uptake rate and its relationship with therapeutic effect]

OBJECTIVE

To evaluate the measurement of 153Sm-EDTMP Bone uptake rate with whole-body scintigraphy and analyze the relationship between bone uptake rate and therapeutic effect.

METHODS

66 patients with bony metastases were examined with whole-body scintigraphy 10 minutes and 6 hours after the administration of 153Sm-EDTMP, and then bone uptake rate was calculated.

RESULTS

The bone uptake rate in 66 patients ranged from 31.9% to 86.6%, (mean 56.0%). The patients with higher bone uptake rate had better overall therapeutic effect. According to the bone uptake rate calculated by whole-body scintigraphy, the therapy activity administered within the limit of bone marrow absorbed dose of 1400 mGy in these patients was 1.40-2.27GBq (mean 1.90 GBq).

CONCLUSION

The present authors have developed a whole-body scintigraphic technique which is simple and reliable in calculating prospectively a safe and effective dose of 153Sm-EDTMP for palliating the patient's painful bone metastases without myelotoxicity.

[Gly40Ser mutation of glucagon receptor gene and NIDDM in Han nationality]

OBJECTIVE

To ascertain whether Gly40Ser mutation in exon 2 of glucagon receptor (GCG-R) gene is associated with late-onset non-insulin-dependent diabetes millitus (NIDDM) in Chinese.

METHODS

We selected 82 NIDDM patients and 136 controls of Han nationality in Hunan province, and detected Gly40Ser mutation using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

None of Gly40Ser mutation was found in all subjects.

CONCLUSIONS

The mutation doesn't associate with NIDDM in Chinese, even though the mutation was reported to be associated with NIDDM in certain French and Caucasians, genetic heterogeneity of NIDDM among ethnic groups should be considered.

Is population bone mineral density variation linked to the marker D11S987 on chromosome 11q12-13?

Our purpose is to test linkage of human chromosome 11q12-13 to BMD variation. Chromosome 11q12-13 has been linked to three BMD-related phenotypes that are inherited as Mendelian traits in human pedigrees: an autosomal dominant high bone mass trait, autosomal recessive osteoporosis pseudoglioma, and autosomal recessive osteopetrosis. A sibling pair study with 374 sibships showed significant linkage of D11S987 to normal BMD variation, with a maximum logarithm of odds score of 3.5. However, a subsequent linkage study with a total of 595 sibling pairs demonstrated reduced significance for linkage of D11S987 to bone mineral density variation, with a logarithm of odds score less than 2.2. We genotyped five markers in a genomic region of approximately 27 cM centering on D11S987 and measured bone mineral density and other traits (weight, etc.) for 635 individuals from 53 human pedigrees. Each of these pedigrees was ascertained through a proband with bone mineral density Z-scores less than -1.28 at the hip or spine. Adjusting for age, sex, and weight as covariates, we performed two-point and multipoint linkage analyses using the variance component linkage analysis method implemented in Sequential Oligogenic Linkage Analysis Routines. We found little evidence of linkage of these five markers to bone mineral density at the spine, hip, wrist and total body bone mineral content. The maximum logarithm of odds score at these five markers was 0.25, and the maximum logarithm of odds score at D11S987 was 0.15. Therefore, although we cannot exclude the linkage of D11S987 region to bone mineral density variation, there is no evidence for linkage of the marker D11S987 on human chromosome 11q12-13 to bone mineral density variation in our study population.

[Serum markers and pathological evaluation in hepatitis fibrosis of chronic hepatitis B treated with interferon alpha]

OBJECTIVE

To evaluate the anti-fibrotic effect of interferon alpha and to study the relationship between the anti-fibrotic effect and the efficacy of anti-virus in patients with chronic hepatitis B treated with interferon alpha.

METHODS

Thirty-six patients with chronic hepatitis B were treated with interferon alpha. Before, during and after the treatment, the levels of hyaluronic acid (HA), type III procollagen (PC-III), type IV collagen(IV-C), laminin (LN) and transforming growth factor beta 1 (TGF-beta 1) were measured as the markers of hepatic fibrosis. Needle biopsy sections of the liver taken before and at the end of IFN treatment were assessed and compared according to the modified histological activity index (HAI) and hepatic fibrosis (HF) scoring system.

RESULTS

In IFN group, the levels of HA, PC-III, IV-C, LN, and TGF-beta 1 after treatment were all significantly lower than those before treatment (P<0.01). The levels of HA, PC-III, and TGF-beta 1 after treatment were significantly lower in IFN group than in control one. HAI scores decreased from 9.3+/-3.2 to 6.2 +/-2.1 and HF scores decreased from 7.5+/-2.2 to 5.1+/-1.8 after treatment.

CONCLUSIONS

The improvement of hepatic fibrosis closely related to the efficacy of anti-virus. Interferon alpha therapy is effective for hepatic fibrosis of chronic hepatitis B.

Toward high-throughput genotyping: dynamic and automatic software for manipulating large-scale genotype data using fluorescently labeled dinucleotide markers

To efficiently manipulate large amounts of genotype data generated with fluorescently labeled dinucleotide markers, we developed a Microsoft database management system, named. offers several advantages. First, it accommodates the dynamic nature of the accumulations of genotype data during the genotyping process; some data need to be confirmed or replaced by repeat lab procedures. By using, the raw genotype data can be imported easily and continuously and incorporated into the database during the genotyping process that may continue over an extended period of time in large projects. Second, almost all of the procedures are automatic, including autocomparison of the raw data read by different technicians from the same gel, autoadjustment among the allele fragment-size data from cross-runs or cross-platforms, autobinning of alleles, and autocompilation of genotype data for suitable programs to perform inheritance check in pedigrees. Third, provides functions to track electrophoresis gel files to locate gel or sample sources for any resultant genotype data, which is extremely helpful for double-checking consistency of raw and final data and for directing repeat experiments. In addition, the user-friendly graphic interface of renders processing of large amounts of data much less labor-intensive. Furthermore, has built-in mechanisms to detect some genotyping errors and to assess the quality of genotype data that then are summarized in the statistic reports automatically generated by. The can easily handle >500,000 genotype data entries, a number more than sufficient for typical whole-genome linkage studies. The modules and programs we developed for the can be extended to other database platforms, such as Microsoft SQL server, if the capability to handle still greater quantities of genotype data simultaneously is desired.

[Clinical study of P-gp, and bcl-2 protein expression in non-Hodgkin's lymphomas patients]

OBJECTIVE

To investigate the relationship between the expression of P-gp, P26-bcl-2 and the prognosis in intermediate and high grade non-Hodgkin's lymphomas (NHL).

METHODS

Sixty cases of intermediate and high grade NHL were retrospectively reviewed using immunohistochemical method. All patients were received CHOP chemotherapy over 4 courses.

RESULTS

P-gp was identified in 15 and P26-bcl-2 in 25 cases. The 3-year survival rates for patients with P26-bcl-2 (+) and P26-bcl-2 (-) were 37.64% and 76.80%, respectively (P < 0.005), and for patients with both positive P-gp and P26-bcl-2 and both negative were 15.38% and 48.48%, respectively (P = 0.038).

CONCLUSIONS

There is direct relationship between the P-gp, P26-bcl-2 protein expression and the prognosis in intermediate and high grade non-Hodgkin's lymphoma.

Affected sibling pair linkage analysis of qualitative and quantitative traits for schizophrenia on chromosome 22 in a Chinese population

We performed nonparametric linkage analysis on 136 families with two or more siblings with schizophrenia from Sichuan, southwestern China. In addition to categorical diagnosis, we used quantitative trait information from the Positive and Negative Symptom Scale and the modified Overt Aggression Scale. Categorical analysis using the diagnosis of schizophrenia and a maximum likelihood identity-by-descent method produced scores of close to 0 throughout the whole region tested. Multipoint analysis allowed exclusion of most markers with a relative risk of > 2, but did not exclude the possibility of a relative risk of < 1.5 for four of the markers. Our results provide no significant evidence for a locus for schizophrenia on chromosome 22. Quantitative linkage analysis using the PANSS-G scale score produced a maximum LOD score of approximately 1.2 with the marker D22S310, using either the Haseman-Elston method or maximum likelihood variance estimation with or without dominance. PANSS-N produced a maximum LOD score of 1.2 at the D22S283 locus. LOD score of about 1 are easily produced by chance. Thus, we conclude that under quantitative trait we also find no evidence of linkage between schizophrenia and markers on chromosome 22 in our Chinese sibling pair sample.

Dynamics of protein ligand binding on multiple time scales: NADH binding to lactate dehydrogenase

Although the importance of atomic motion to how proteins function has been conjectured for several decades, the characterization of protein dynamics on multiple time scales is scant. This is because of severe experimental and theoretical difficulties, particularly characterizing the nanosecond to millisecond time scales. Here, we apply advanced laser-induced temperature-jump relaxation spectroscopic techniques to examine the kinetics of NADH binding to lactate dehydrogenase over this time scale. The bimolecular rate process, at about 290 micros, is easily observed as are multiple faster events (with relaxation times of 200 ns, 3.5 micros, and 24 micros), revealing a rich dynamical nature of the binding step. The results show that there are multiple structures of bound enzyme-ligand complexes, some of which are likely to be far from the catalytically productive structure. The results have important implications for interpretations of the binding thermodynamics of ligands to LDH and, by extension, to other proteins. The observed processes likely play a role in the dynamics of the chemistry that is catalyzed by lactate dehydrogenase.

Vibrational structure of GDP and GTP bound to RAS: an isotope-edited FTIR study

A complete vibrational description of the bonding of a ligand to a protein requires the assignment of both symmetric and antisymmetric vibrational modes. The symmetric modes of isotopically enriched enzyme-bound ligands can be obtained by Raman difference spectroscopy, but until now, the antisymmetric modes, which require IR difference spectroscopy, have not been generally accessible. We have developed the methodology needed to perform IR difference spectroscopy, assign the antisymmetric modes, and accurately describe bonding. The method is used to assess the bonding changes that occur as Mg.GDP and Mg.GTP move from solution into the active site of RAS. Binding to RAS opens the nonbridging, O--P--O angle of the gamma-phosphate of GTP by 2.7 degrees, yet the angular freedom (dispersion of the O--P--O angle) of the gamma-phosphate is comparable to that in solution. In contrast, the motion of the beta-phosphate of GDP is highly restricted, suggesting that it positions the gamma-phosphate for nucleophilic attack. The beta,gamma-bridging O-P bond of bound GTP is slightly weakened, being lengthened by 0.005 A in the active site, corresponding to a bond order decrease of 0.012 valence unit (vu). The observed binding changes are consistent with a RAS-mediated hydrolysis mechanism that parallels that for solution hydrolysis.

Entanglement, interference, and measurement in a degenerate parametric oscillator

Quantum dynamical equations of motion for homodyne detection of the degenerate optical parametric oscillator are solved exactly. Nonclassical photon statistics are shown to be a consequence of interference of probability amplitudes, entanglement of photon pairs from such an oscillator, and the role of measurement in quantum evolution.

Precise measurement of the positive muon anomalous magnetic moment

A precise measurement of the anomalous g value, a(mu) = (g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron. The result a(mu+) = 11 659 202(14) (6) x 10(-10) (1.3 ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The current theoretical value from the standard model is a(mu)(SM) = 11 659 159.6(6.7) x 10(-10) (0.57 ppm) and a(mu)(exp) - a(mu)(SM) = 43(16) x 10(-10) in which a(mu)(exp) is the world average experimental value.

[Progress in the studies on the molecular genetics of schizophrenia]

Although population genetic studies have long confirmed the genetic vulnerability of schizophrenia,ongoing advances in molecular genetic technology and biostatistic analysis are only now making it possible to search for the susceptibility gene of the disease. This article reviewed some of the recent findings in this area: (1) The heritability of schizophrenia is estimated around 60%-80%. The phenotype differentiation is based on standard diagnostic scales and symptom rating scales. (2) The two main approaches to finding the genes that influence the disorder are now genomic scan and candidate gene detection. Affected sib-pair (ASP) method and transmission disequilibrium test(TDT) are considered promising analyses. (3) The positive candidate regions with some independent replicable reports concentrated on 6p, 22q and 8p. Positive findings of candidate gene research involved 5-HT2A receptor, DRD3, NT-3, etc. Further directions to identify the susceptibility genes include: Applying more precise instruments to define clinical phenotype of the disease. Application of proper biological markers such as electrophysiologic parameters and brain imaging will be a prospective approach. Using larger sample to increase statistic power and developing more powerful statistic analysis, and performing advanced molecular genetic technique such as DNA pooling, DNA chips, genomic mismatch scanning (GMS), representational difference analysis(RDA), comparative genomic hybridization(CGH) and two-dimensional DNA typing methods will also facilitate this research area to greater perspective.

Lung inflammation in hyperoxia can be prevented by antichemokine treatment in newborn rats

Hyperoxia may contribute to lung disease in newborns through effects on alveolar neutrophils which predominate in respiratory distress syndrome and other acute lung injuries. Neutrophil chemokines such as interleukin-8 (IL-8) regulate chemoattraction, and are elevated in tracheal aspirates of newborns who develop bronchopulmonary dysplasia (BPD). Blockade of neutrophil chemokines may reduce hyperoxia-induced inflammatory lung injury and BPD. We therefore tested the hypothesis that hyperoxia contributes to elevations of rat neutrophil chemokines, cytokine-induced neutrophil chemoattractant-1 (CINC-1), and macrophage inflammatory protein-2 (MIP-2) in newborn rat lung. Newborn rats were exposed to air or 95% O(2) for 8 d. CINC-1 and MIP-2 were measured in whole lung homogenates by ELISA. Newborn 95% O(2)-exposed animals were given anti-CINC-1 or anti-MIP-2, 1, 5, or 10 microg on Days 3 and 4 of 95% O(2) exposure. Bronchoalveolar lavage (BAL) was performed after perfusion on day 6 to evaluate airway neutrophils, and myeloperoxidase (MPO) was measured in perfused whole lung. Lungs were examined histologically and immunohistochemically for effects of 95% O(2) +/- antichemokine. CINC-1 and MIP-2 increased nearly tenfold by Day 8 95% O(2) treatment versus air control. CINC-1 and MIP-2 immunolabeling was increased in alveolar macrophages and alveolar epithelium in 95% O(2). Anti-CINC-1 and anti-MIP-2 treatment at every dose reduced neutrophil number > 90% in BAL. Anti-CINC-1 10 microg reduced tissue MPO by 50%. Antichemokine treatment on days 3 and 4 prevented alveolar septal thickening and reduced chemokine immunolabeling on Day 6. Hyperoxia-induced neutrophil influx is mediated in part by CINC-1 and MIP-2 in newborn rats and can be partially prevented by treatment with anti-CINC-1 and anti-MIP-2.

A vibrational structure of 7,8-dihydrobiopterin bound to dihydroneopterin aldolase

Dihydroneopterin aldolase (DHNA) catalyzes the conversion of 7, 8-dihydroneopterin to 6-hydroxymethyl-7,8-dihydropterin and glycolaldehyde. An inhibitor of the enzyme, 7,8-dihydrobiopterin, free in solution and bound in its complex with the enzyme has been studied by Raman difference spectroscopy. By using isotopically labeled 7,8-dihydrobiopterin and normal mode analyses based on ab initio quantum mechanic methods, we have positively identified some of the Raman bands in the enzyme-bound inhibitor, particularly the important N5=C6 stretch mode. The spectrum of the enzyme-bound inhibitor shows that the pK(a) of N5 is not significantly increased in the complex. This result suggests that N5 of 7,8-dihydroneopterin is not protonated before the bond cleavage of 7,8-dihydroneopterin during the DHNA-catalyzed reaction as has been suggested. Our results also show that the N5=C6 stretch mode of 7, 8-dihydrobiopterin shifts 19 cm(-)(1) upon binding to DHNA. Various possibilities on how the enzyme can bring about such large frequency change of the N5=C6 stretch mode are discussed.

Determination of bone mineral density of the hip and spine in human pedigrees by genetic and life-style factors

In 40 human pedigrees with 563 subjects, we evaluated the contribution of genetic and life-style factors (exercise, smoking, and alcohol consumption) and the interactions between non-genetic factors in determining bone mineral density (BMD) of the hip and spine. In our analysis, we adjusted for age, weight, height, menopausal status in females, life-style factors, and the significant interactions among these factors. For the spine and hip BMD, heritabilities (h(2)) (+/- SE) were, respectively, 0.68 (0.21) and 0.86 (0.28) in males and 0.64 (0.13) and 0.67 (0.14) in females. Exercise had significant beneficial effects for male spine BMD and female hip BMD. Alcohol consumption experienced in our sample had significant beneficial effects on hip BMD in both sexes. Although the main effect of smoking was not significant, there were significant interaction effects between smoking and other important factors (e.g., exercise, weight, alcohol consumption). For example, for female spine BMD, exercise had significant beneficial effects in smokers; however, its effect in non-smokers was non-significant. This result indicates that exercise may reduce deleterious effects of smoking (if any) on BMD, but may have minor effects in increasing BMD in non-smokers. The various interaction effects among risk factors explicitly revealed here for the first time indicate that the detailed effects and direction of individual risk factors may depend on the presence and magnitude of other factors. Weight invariably affected BMD of the hip and spine in both sexes. Age effects were significant for hip BMD, but not for male spine BMD.

Structural basis of polyamine-DNA recognition: spermidine and spermine interactions with genomic B-DNAs of different GC content probed by Raman spectroscopy

Four genomic DNAs of differing GC content (Micrococcus luteus, 72% GC; Escherichia coli, 50% GC; calf thymus, 42% GC; Clostridium perfringens, 27% GC) have been employed as targets of interaction by the cationic polyamines spermidine ([H(3)N(CH(2))(3)NH(2)(CH(2))(4)NH(3)](3+)) and spermine ([(CH(2))(4)(NH(2)(CH(2))(3)NH(3))(2)](4+)). In solutions containing 60 mM DNA phosphate (approximately 20 mg DNA/ml) and either 1, 5 or 60 mM polyamine, only Raman bands associated with the phosphates exhibit large spectral changes, demonstrating that B-DNA phosphates are the primary targets of interaction. Phosphate perturbations, which are independent of base composition, are consistent with a model of non-specific cation binding in which delocalized polyamines diffuse along DNA while confined by the strong electrostatic potential gradient perpendicular to the helix axis. This finding provides experimental support for models in which polyamine-induced DNA condensation is driven by non-specific electrostatic binding. The Raman spectra also demonstrate that major groove sites (guanine N7 and thymine C5H(3)) are less affected than phosphates by polyamine-DNA interactions. Modest dependence of polyamine binding on genome base composition suggests that sequence context plays only a secondary role in recognition. Importantly, the results demonstrate that polyamine binding has a negligible effect on the native B-form secondary structure. The capability of spermidine or spermine to bind and condense genomic B-DNA without disrupting the native structure must be taken into account when considering DNA organization within bacterial nucleoids or cell nuclei.

Association of estrogen receptor-alpha genotypes with body mass index in normal healthy postmenopausal Caucasian women

Several lines of evidence suggest the importance of the estrogen receptor (ER) in determining body mass index (BMI). Our purpose was to investigate whether genetic polymorphisms at the restriction enzyme PvuII site of the ER-alpha gene locus are associated with BMI variation. Data on BMI, age, and ER-alpha genotypes were obtained from 108 healthy midwestern U.S. postmenopausal Caucasian women. The study subjects were unrelated and aged 65 yr and over (mean age +/- SD, 73.4 +/- 5.1 yr), with an average BMI of 25.25 (SD, 4.04). The ER-alpha genotypes were obtained by PCR followed by restriction enzyme PvuII digestion. We found that in our study subjects the ER-alpha genotypes are significantly associated with BMI (by ANOVA, P = 0.04), explaining about 6.2% of the BMI variation in our study sample. The allelic effects of this locus on BMI are approximately additive. In our sample, individuals of the PP and Pp genotypes have, respectively, 11.4% and 4.8% higher BMI than individuals of the pp genotype. There is a significant ER-alpha genotype by age interaction, so that in our sample PP individuals tend to gain weight with age, whereas Pp and pp individuals tend to lose weight with age. Therefore, the ER-alpha polymorphisms are associated with BMI variation in healthy postmenopausal Caucasian women aged 65 yr and over. Our result is consistent with some recent findings suggesting the potential effects of the ER on BMI. The importance of the ER-alpha genotypes in other populations and other age groups needs to be demonstrated. Although the results of the ER-alpha genotype by age interaction are obtained here from cross-sectional data, direct confirmation may come from longitudinal studies in which individuals are measured multiple times over several years. The importance of the ER-alpha genotypes on BMI should be confirmed by further studies using methods robust to the potential problem of population substructuring that may confound the conclusions of population association studies.

Nuclear factor kappaB subunits induce epithelial cell growth arrest

Nuclear factor kappaB (NF-kappaB) gene-regulatory proteins play important roles in inflammation, neoplasia, and programmed cell death. Recently, blockade of NF-kappaB function has been shown to result in epithelial hyperplasia, suggesting a potential role for NF-kappaB in negative growth regulation. We expressed active NF-kappaB subunits in normal epithelial cells and found that NF-kappaB profoundly inhibits cell cycle progression. This growth inhibition is resistant to mitogenic stimuli and is accompanied by other features of irreversible growth arrest. NF-kappaB-triggered cell cycle arrest is also associated with selective induction of the cyclin-dependent kinase inhibitor p21CiP1, with overexpression of p21(Cip1) alone inducing findings similar to those seen with NF-kappaB in vitro. An active NF-kappaB subunit expressed in the epidermis of p21(CiP1-/- mice, however, displays only partial growth-inhibitory effects, suggesting that full NF-kappaB growth inhibition is only partially p21(Cip1) dependent in this setting. These data indicate that NF-kappaB can trigger cell cycle arrest in epithelial cells in association with selective induction of a cell cycle inhibitor.

Topology of catalytic portion of prostaglandin I(2) synthase: identification by molecular modeling-guided site-specific antibodies

Prostaglandin I(2) synthase (PGIS) is an eicosanoid-synthesizing cytochrome P450, located in the endoplasmic reticulum (ER) membrane. The membrane topology of the catalytic portion of PGIS is still unknown. General models of the membrane topology of microsomal P450s have been proposed in two forms: (a) large part of the polypeptide exposed on the cytoplasmic side with an NH(2)-terminal membrane anchor to the ER membrane and (b) deep immersion of the polypeptide in the membrane, as described by J. P. Miller et al. (1996, Biochemistry 35, 1466-1474). We have characterized the membrane topology of catalytic portion of PGIS using molecular modeling-guided site-specific antibodies. A 3D working model of PGIS was constructed by homology modeling using P450(BM-3) crystal structure as a template (S. K. Shyue et al., 1997, J. Biol. Chem. 272, 3657-3662). Three hydrophilic peptides corresponding to different regions of the surface portion of PGIS with residues 109-127 (P109-127), 353-368 (P353-368), and 411-431 (P411-431) predicted from the model and an NH(2)-terminal hydrophobic peptide (residues 1-28, P1-28) were synthesized and used to prepare site-specific antibodies. All three of the hydrophilic peptide antibodies have high titer and are specifically recognized human PGIS, as shown by binding assays and Western blot analysis. In contrast, the hydrophobic NH(2)-terminal peptide has a much lower titer binding to the PGIS protein. The overall arrangement of the PGIS polypeptide with respect to the endoplasmic reticulum (ER) membrane was examined by immunocytochemistry techniques in transiently transfected COS-1 cells with recombinant human PGIS cDNA and in ECV cells expressing endogenous PGIS. The immunofluorescence staining for the cells with selective permeabilization of the plasma membrane using streptolysin O indicated that all three of the hydrophilic peptide antibodies bound to the cytoplasmic surface of the ER membrane. These results provide direct experimental evidence supporting the predicted 3D protein topological model in which the segments are located on the protein surface and the membrane topological model in which PGIS is largely exposed on the cytoplasmic side of the ER membrane. It also led us to conclude that the PGIS substrate, prostaglandin H(2) (PGH(2)), produced by prostaglandin H(2) synthase (PGHS) in the ER lumenal side must pass through the ER membrane barrier to the catalytic site of the PGIS in the cytoplasmic side of the ER membrane.

Genetic determination of Colles' fracture and differential bone mass in women with and without Colles' fracture

Osteoporotic fractures (OFs) are a major public health problem. Direct evidence of the importance and, particularly, the magnitude of genetic determination of OF per se is essentially nonexistent. Colles' fractures (CFs) are a common type of OF. In a metropolitan white female population in the midwestern United States, we found significant genetic determination of CF. The prevalence (K) of CF is, respectively, 11.8% (+/- SE 0.7%) in 2471 proband women aged 65.55 years (0.21), 4.4% (0.3%) in 3803 sisters of the probands, and 14.6% (0.7%) in their mothers. The recurrence risk (K0), the probability that a woman will suffer CF if her mother has suffered CF is 0.155 (0.017). The recurrence risk (Ks), the probability that a sister of a proband woman will suffer CF given that her proband sister has suffered CF is 0.084 (0.012). The relative risk lambda (the ratio of the recurrence risk to K), which measures the degree of genetic determination of complex diseases such as CF, is 1.312 (0.145; lambda 0) for a woman with an affected mother and 1.885 (0.276; lambda s) for a woman with an affected sister. A lambda-value significantly greater than 1.0 indicates genetic determination of CF. The terms lambda 0 and lambda s are related to the genetic variances of CF. These parameters translate into a significant and moderately high heritability (0.254 [0.118]) for CF. These parameters were estimated by a maximum likelihood method that we developed, which provides a general tool for characterizing genetic determination of complex diseases. In addition, we found that women without CF had significantly higher bone mass (adjusted for important covariates such as age, weight, etc.) than women with CF.