[Quantitative analysis of thirty-one elements in the stained dental fluorosis of enamel]

OBJECTIVE

To study the relationship between concentrations of thirty elements and fluorine element in teeth with stained dental fluorosis from high fluoride water area and teeth from normal fluoride area.

METHODS

The concentration of thirty-one elements in 43 teeth was measured by plasmatron spectrographic analysis and fluoride selective electrode.

RESULTS

1. Content of F, P, Ca, Mn, As, Se, Al, Ti, Mo, B elements in enamel had a direct relationship to severity of enamel staining. 2. Content of Mn, As, Se, Sr, Nb, Ca, P elements were high positively related to content of fluorine in enamel (P < 0.05).

CONCLUSION

Mn, As, Se, F content is closely related to the pigment formation in dental fluorosis of enamel.

New ribosomal RNA gene locations in Gossypium hirsutum mapped by meiotic FISH

In this study we have mapped newly identified rDNA loci in Gossypium hirsutum. Four new minor 18S-26S rDNA loci, in addition to the sites previously identified, were mapped using fluorescence in situ hybridization (FISH) to heterozygous translocation (NT) quadrivalents (IVs). The newly detected 18S-26S rDNA loci were mapped to the right arms of chromosomes 8, 9, 15, 17, 19, 20, and 23 and the left arms of chromosomes 5, 11, 12, and 14. Using the rDNA loci as common reference points, we detected several erroneous arm assignments in the previously published map of NT breakpoints. The data are summarized in the form of an integrated map for all 17 known rDNA loci, relative to centromeres, telomeres, and NT breakpoints. This information will facilitate future locus-specific research on rRNA gene evolution and function.

A novel imprinted gene, encoding a RING zinc-finger protein, and overlapping antisense transcript in the Prader-Willi syndrome critical region

We describe a complex imprinted locus in chromosome 15q11-q13 that encodes two genes, ZNF127 and ZNF127AS. The ZNF127 gene encodes a protein with a RING (C3HC4) zinc-finger and multiple C3H zinc-finger motifs, the former being closely related to a protein from variola major virus, the smallpox etiological agent. These motifs allow prediction of ZNF127 function as a ribonucleoprotein. The intronless ZNF127 gene is expressed ubiquitously, but the entire coding sequence and 5' CpG island overlaps a second gene, ZNF127AS, that is transcribed from the antisense strand with a different transcript size and pattern of expression. Allele-specific analysis shows that ZNF127 is expressed only from the paternal allele. Consistent with this expression pattern, in the brain the ZNF127 5' CpG island is completely unmethylated on the paternal allele but methylated on the maternal allele. Analyses of adult testis, sperm and fetal oocytes demonstrates a gametic methylation imprint with unmethylated paternal germ cells. Recent findings indicate that ZNF127 is part of the coordinately regulated imprinted domain affected in Prader-Willi syndrome patients with imprinting mutations. Therefore, ZNF127 and ZNF127AS are novel imprinted genes that may be associated with some of the clinical features of the polygenic Prader-Willi syndrome.

Recombinant influenza A virus vaccines for the pathogenic human A/Hong Kong/97 (H5N1) viruses

Recombinant reassortment technology was used to prepare H5N1 influenza vaccine strains containing a modified hemagglutinin (HA) gene and neuraminidase gene from the A/Hong Kong/156/97 and A/Hong Kong/483/97 isolates and the internal genes from the attenuated cold-adapted A/Ann Arbor/6/60 influenza virus strain. The HA cleavage site (HA1/HA2) of each H5N1 isolate was modified to resemble that of "low-pathogenic" avian strains. Five of 6 basic amino acids at the cleavage site were deleted, and a threonine was added upstream of the remaining arginine. The H5 HA cleavage site modification resulted in the expected trypsin-dependent phenotype without altering the antigenic character of the H5 HA molecule. The temperature-sensitive and cold-adapted phenotype of the attenuated parent virus was maintained in the recombinant strains, and they grew to 108.5-9.4 EID50/mL in eggs. Both H5N1 vaccine virus strains were safe and immunogenic in ferrets and protected chickens against wild-type H5N1 virus challenge.

Analysis of sarcoplasmic reticulum Ca2+ transport and Ca2+ ATPase enzymatic properties using mouse cardiac tissue homogenates

Recent studies have focused on developing transgenic mouse models to explore the physiological roles of sarcoplasmic reticulum (SR) calcium handling proteins. The goal of this study was to develop methodology to measure SR Ca2+ transport function and enzymatic properties of SR Ca2+ ATPase (SERCA) in individual mouse hearts. We describe here the procedures to specifically measure SR Ca2+ uptake, the formation and decomposition of SERCA phosphoenzyme intermediate (E-P) in mouse cardiac homogenates. The specificity of SERCA enzymatic activity in cardiac homogenates was established by (a) the selective inhibition of SERCA enzyme by inhibitor-thapsigargin, and (b) comparison of the kinetic parameters of SERCA activity between homogenates and isolated microsomes. Here we show that the apparent affinity of SERCA for Ca2+ and ATP, the time to reach steady-state levels of E-P, and the rate of E-P decomposition (turnover rate of SERCA enzyme) are similar in homogenates and microsomes. These studies demonstrate that SERCA Ca2+ transport and enzymatic properties can be accurately measured in mouse cardiac tissue homogenates. Additionally, we show that frozen cardiac homogenates can be used without significant loss of enzymatic activity. In conclusion, we have developed and established the methods to employ tissue homogenates to study SR Ca2+ transport function in individual mouse hearts.

[Effect of Callicarpa herbs on antioxidation in vitro]

The concentration of half inhibition (IC50) of Callicarpa herbs, including Callicarpa kochiana(Ck), C. bodinieri (Cb) and its fruit (Cbf), C. japonica, C. macrophrlla, C. cathaarana, C. giraldi(Cg) on lipid peroxidation (LPO) of tissus homogenate incubated in 37 +/- 0.5 degrees C were tested. The result showed that all but Cg could inhibit lipid peroxidation. The IC50 of Cbf was minimum. IC50 of Cb, Cbf and Ck inhibiting red blood cell (RBC) LPO and hemolysis caused by hydroxyl free radical (.OH), inhibiting brain homogenate LPO induced by .OH and inhibiting or clean .OH formation by system of H2O2 and FeSO4 were also tested. It was found the IC50 were Cbf > Cb > Ck. These results suggested that the most strong inhibitor to automatic LPO reaction was Cbf, but to LPO caused by .OH was Ck.

Targeted mutation of plasma phospholipid transfer protein gene markedly reduces high-density lipoprotein levels

It has been proposed that the plasma phospholipid transfer protein (PLTP) facilitates the transfer of phospholipids and cholesterol from triglyceride-rich lipoproteins (TRL) into high-density lipoproteins (HDL). To evaluate the in vivo role of PLTP in lipoprotein metabolism, we used homologous recombination in embryonic stem cells and produced mice with no PLTP gene expression. Analysis of plasma of F2 homozygous PLTP-/- mice showed complete loss of phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, sphingomyelin, and partial loss of free cholesterol transfer activities. Moreover, the in vivo transfer of [3H]phosphatidylcholine ether from very-low-density proteins (VLDL) to HDL was abolished in PLTP-/- mice. On a chow diet, PLTP-/- mice showed marked decreases in HDL phospholipid (60%), cholesterol (65%), and apo AI (85%), but no significant change in non-HDL lipid or apo B levels, compared with wild-type littermates. On a high-fat diet, HDL levels were similarly decreased, but there was also an increase in VLDL and LDL phospholipids (210%), free cholesterol (60%), and cholesteryl ester (40%) without change in apo B levels, suggesting accumulation of surface components of TRL. Vesicular lipoproteins were shown by negative-stain electron microscopy of the free cholesterol- and phospholipid-enriched IDL/LDL fraction. Thus, PLTP is the major factor facilitating transfer of VLDL phospholipid into HDL. Reduced plasma PLTP activity causes markedly decreased HDL lipid and apoprotein, demonstrating the importance of transfer of surface components of TRL in the maintenance of HDL levels. Vesicular lipoproteins accumulating in PLTP-/- mice on a high-fat diet could influence the development of atherosclerosis.

The ancestral gene for transcribed, low-copy repeats in the Prader-Willi/Angelman region encodes a large protein implicated in protein trafficking, which is deficient in mice with neuromuscular and spermiogenic abnormalities

Transcribed, low-copy repeat elements are associated with the breakpoint regions of common deletions in Prader-Willi and Angelman syndromes. We report here the identification of the ancestral gene ( HERC2 ) and a family of duplicated, truncated copies that comprise these low-copy repeats. This gene encodes a highly conserved giant protein, HERC2, that is distantly related to p532 (HERC1), a guanine nucleotide exchange factor (GEF) implicated in vesicular trafficking. The mouse genome contains a single Herc2 locus, located in the jdf2 (juvenile development and fertility-2) interval of chromosome 7C. We have identified single nucleotide splice junction mutations in Herc2 in three independent N-ethyl-N-nitrosourea-induced jdf2 mutant alleles, each leading to exon skipping with premature termination of translation and/or deletion of conserved amino acids. Therefore, mutations in Herc2 lead to the neuromuscular secretory vesicle and sperm acrosome defects, other developmental abnormalities and juvenile lethality of jdf2 mice. Combined, these findings suggest that HERC2 is an important gene encoding a GEF involved in protein trafficking and degradation pathways in the cell.

S-nitrosylation and S-glutathiolation of protein sulfhydryls by S-nitroso glutathione

The modification of reactive protein sulfhydryls by S-nitrosoglutathione and other NO donors has been studied by gel isoelectric focusing. S-nitrosylated, unmodified, and S-glutathiolated protein forms are differentiated by this method. With specific antibodies for the protein of interest, both S-nitrosylation and S-glutathiolation of the protein were analyzed in mixtures obtained as soluble tissue or cell extracts. The effect of S-nitrosoglutathione (GSNO) on purified phosphorylase b, on carbonic anhydrase III in an extract from rat liver, and on H-ras expressed in Escherichia coli was examined. When fresh GSNO reacted with pure phosphorylase b, only S-nitrosylated forms of the protein were observed. Likewise the NO donors, amyl nitrite, spermine NONOate, and diethylamine NONOate, all generated S-nitrosylated phosphorylase b. When crude mixtures of proteins from rat liver (containing carbonic anhydrase III) or from E. coli (containing an overexpressed form of H-ras) were exposed to fresh GSNO, both the S-nitrosylated and the S-glutathiolated forms of the proteins were observed. It is suggested that reactive intermediates from the breakdown of GSNO are responsible for the observed S-glutathiolation. These experiments show that both S-nitrosylated and S-glutathiolated forms of proteins may be generated by the addition of GSNO to mixtures containing proteins with reactive sulfhydryls. These protein modifications may exhibit metabolic consequences independent of the release of nitric oxide.

A candidate recombination modifier gene for Zea mays L

Maize meiotic mutant desynaptic (dy) was tested as a candidate recombination modifier gene because its effect is manifested in prophase I. Recombination rates for desynaptic (dy) and its wild type were compared in two ways: (1) segregation analysis using six linked molecular markers on chromosome 1L and (2) cytogenetic analysis using fluorescence in situ hybridization (FISH)-aided meiotic configurations observed in metaphase I. Chromosome 1L map lengths among the six linked markers were 45-63 cM for five F2 dy/dy plants, significantly lower than the wild-type F2 map distance of 72 cM. Chromosomes 2 and 6 were marked with rDNA FISH probes, and their map lengths were estimated from FISH-adorned meiotic configurations using the expectation-maximization algorithm. Chiasma frequencies for dy/dy plants were significantly reduced for both arms of chromosome 2, for chromosome arm 6L, and for eight unidentified chromosomes. There was a notable exception for the nucleolus-organizing region-bearing arm chromosome arm 6S, where dy increased chiasma frequency. Maize meiotic mutant desynaptic is a recombination modifier gene based on cytogenetic and segregation analyses.

Impaired cardiac performance in heterozygous mice with a null mutation in the sarco(endo)plasmic reticulum Ca2+-ATPase isoform 2 (SERCA2) gene

The sarco(endo)plasmic reticulum Ca2+-ATPase isoform 2 (SERCA2) gene encodes both SERCA2a, the cardiac sarcoplasmic reticulum Ca2+ pump, and SERCA2b, which is expressed in all tissues. To gain a better understanding of the physiological functions of SERCA2, we used gene targeting to develop a mouse in which the promoter and 5' end of the gene were eliminated. Mating of heterozygous mutant mice yielded wild-type and heterozygous offspring; homozygous mutants were not observed. RNase protection, Western blotting, and biochemical analysis of heart samples showed that SERCA2 mRNA was reduced by approximately 45% in heterozygous mutant hearts and that SERCA2 protein and maximal velocity of Ca2+ uptake into the sarcoplasmic reticulum were reduced by approximately 35%. Measurements of cardiovascular performance via transducers in the left ventricle and right femoral artery of the anesthetized mouse revealed reductions in mean arterial pressure, systolic ventricular pressure, and the absolute values of both positive and negative dP/dt in heterozygous mutants. These results demonstrate that two functional copies of the SERCA2 gene are required to maintain normal levels of SERCA2 mRNA, protein, and Ca2+ sequestering activity, and that the deficit in Ca2+ sequestering activity due to the loss of one copy of the SERCA2 gene impairs cardiac contractility and relaxation.

SERCA1a can functionally substitute for SERCA2a in the heart

We recently generated a transgenic (TG) mouse model in which the fast-twitch skeletal muscle sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA1a) is overexpressed in the heart. Ectopic overexpression of SERCA1a results in remodeling of the cardiac SR containing 80% SERCA1a and 20% endogenous SERCA2a with an approximately 2.5-fold increase in the total amount of SERCA protein (E. Loukianov et al. Circ. Res. 83: 889-897, 1998). We have analyzed the Ca2+ transport properties of membranes from SERCA1a TG hearts in comparison to control hearts. Our data show that the maximal velocity of SR Ca2+ transport was significantly increased ( approximately 1.9-fold) in TG hearts, whereas the apparent affinity of the SERCA pump for Ca2+ was not changed. Addition of phospholamban antibody in the Ca2+ uptake assays increased the apparent affinity for Ca2+ to the same extent in TG and non-TG (NTG) hearts, suggesting that phospholamban regulates the SERCA1a pump in TG hearts. Analysis of SERCA enzymatic properties in TG hearts revealed that the SERCA pump affinity for ATP, the Hill coefficient, the pH dependence of Ca2+ uptake, and the effect of acidic pH on Ca2+ transport were similar to those of NTG hearts. Interestingly, the rate constant of phosphoenzyme decay (turnover rate of SERCA enzyme) was also very similar between TG and NTG hearts. Together these findings suggest that 1) the SERCA1a pump can functionally substitute for SERCA2a and is regulated by endogenous phospholamban in the heart and 2) SERCA1a exhibits several enzymatic properties similar to those of SERCA2a when expressed in a cardiac setting.

[The clinical application of triamcinolone to accelerate soft tissue expansion]

OBJECTIVE

To speed up the expansion procedure.

METHODS

Triamcinolone was injected during tissue expansion in 26 cases.

RESULTS

The study proved that triamcinolone shortened the injection interval to 32 +/- 6 hours. The mean time of full expansion was shortened to 20 +/- 5 days in the experimental group. The injection interval and mean time of full expansion were 6 +/- 2 days and 42 +/- 8 days respectively in the control group (P < 0.01). The immediate retraction ratios of expanded skin of the two groups were 17% and 26% respectively.

CONCLUSION

This new method is feasible in clinical application.

Targeted overexpression of the sarcoplasmic reticulum Ca2+-ATPase increases cardiac contractility in transgenic mouse hearts

Cardiac hypertrophy and heart failure are known to be associated with a reduction in Ca2+-ATPase pump levels of the sarcoplasmic reticulum (SR). To determine whether, and to what extent, alterations in Ca2+ pump numbers can affect contraction and relaxation parameters of the heart, we have overexpressed the cardiac SR Ca2+-ATPase specifically in the mouse heart using the alpha-myosin heavy chain promoter. Analysis of 2 independent transgenic lines demonstrated that sarco(endo)plasmic reticulum Ca2+-ATPase isoform (SERCA2a) mRNA levels were increased 3.88+/-0. 4-fold and 7.90+/-0.2-fold over those of the control mice. SERCA2a protein levels were increased by 1.31+/-0.05-fold and 1.54+/-0. 05-fold in these lines despite high levels of mRNA, suggesting that complex regulatory mechanisms may determine the SERCA2a pump levels. The maximum velocity of Ca2+ uptake (Vmax) was increased by 37%, demonstrating that increased pump levels result in increased SR Ca2+ uptake function. However, the apparent affinity of the SR Ca2+-ATPase for Ca2+ remains unchanged in transgenic hearts. To evaluate the effects of overexpression of the SR Ca2+ pump on cardiac contractility, we used the isolated perfused work-performing heart model. The transgenic hearts showed significantly higher myocardial contractile function, as indicated by increased maximal rates of pressure development for contraction (+dP/dt) and relaxation (-dP/dt), together with shortening of the normalized time to peak pressure and time to half relaxation. Measurements of intracellular free calcium concentration and contractile force in trabeculae revealed a doubling of Ca2+ transient amplitude, with a concomitant boost in contractility. The present study demonstrates that increases in SERCA2a pump levels can directly enhance contractile function of the heart by increasing SR Ca2+ transport.

Liver-specific overexpression of scavenger receptor BI decreases levels of very low density lipoprotein ApoB, low density lipoprotein ApoB, and high density lipoprotein in transgenic mice

Scavenger receptor BI (SR-BI) is known to mediate the selective uptake of high density lipoprotein (HDL) cholesteryl ester (CE) in liver and steroidogenic tissues. To evaluate the role of SR-BI in plasma lipoprotein metabolism, we have generated transgenic mice with liver-specific overexpression of murine SR-BI. On a chow diet SR-BI transgenic (SR-BI Tg) mice have decreased HDL-CE, apoA-I, and apoA-II levels; plasma triglycerides, low density lipoprotein (LDL) cholesterol, and very low density lipoprotein (VLDL) and LDL apoB were also decreased, compared with control mice. Turnover studies using non-degradable CE and protein labels showed markedly increased total and selective uptake of HDL-CE in the liver and increased HDL protein catabolism in both liver and kidney. To evaluate the changes in apoB further, mice were challenged with high fat, high cholesterol diets. In SR-BI Tg mice plasma apoB levels were only 3-15% of control levels, and the dietary increase in VLDL and LDL apoB was virtually abolished. These studies show that steady state overexpression of hepatic SR-BI reduces HDL levels and increases reverse cholesterol transport. They also indicate that SR-BI can play a role in the metabolism of apoB-containing lipoproteins. The dual effects of increased reverse cholesterol transport and lowering of apoB-containing lipoproteins that result from hepatic SR-BI overexpression could have anti-atherogenic consequences.

Macromolecular organization and genetic mapping of a rapidly evolving chromosome-specific tandem repeat family (B77) in cotton (Gossypium)

Isolation and characterization of the most prominent repetitive element families in the genome of tetraploid cotton (Gossypium barbadense L; [39]) revealed a small subset of families that showed very different properties in tetraploids than in their diploid progenitors, separated by 1-2 million years. One element, B77, was characterized in detail, and compared to the well-conserved 5S and 45S rRNA genes. The 572 bp B77 repeat was found to be concentrated in several discontinuous tandem arrays confined to a single 550 kb SalI fragment in tetraploid cotton. Genetic mapping based on the absence of the pentameric 'rung' in the G. barbadense 'ladder' showed that B77 maps to a D-subgenome chromosome. In situ hybridization supports the contention that the array is confined largely to a single chromosomal site in the D-subgenome. The B77 repeat has undergone a substantial increase in copy number since formation of tetraploid cotton from its diploid relatives. RFLPs observed among tetraploid cotton species suggest that amplification and/or rearrangement of the repeat may have continued after divergence of the five tetraploid cotton species. B77 contains many short direct repeats and shares significant DNA sequence homology with a Nicotiana alata retrotransposon Tna1-2 integrase motif. The recent amplification of B77 on linkage group D04 suggests that the D-subgenome of tetraploid cotton may be subject to different evolutionary constraints than the D-genome diploid chromosomes, which exhibit few genome-specific elements. Further, the abundance of B77 in G. gossypioides supports independent evidence that it may be the closest extant relative of the D-genome ancestor of cotton.

Enhanced myocardial contractility and increased Ca2+ transport function in transgenic hearts expressing the fast-twitch skeletal muscle sarcoplasmic reticulum Ca2+-ATPase

In this study, we investigated whether the fast-twitch skeletal muscle sarco(endo)plasmic reticulum Ca2+ transport pump (SERCA1a) can functionally substitute the cardiac SERCA2a isoform and how its overexpression affects cardiac contractility. For this purpose, we generated transgenic (TG) mice that specifically overexpress SERCA1a in the heart, using the cardiac-specific alpha-myosin heavy chain promoter. Ectopic expression of SERCA1a resulted in a 2.5-fold increase in the amount of total SERCA protein. At the same time, the level of the endogenous SERCA2a protein was decreased by 50%, whereas the level of other muscle proteins, including calsequestrin, phospholamban, actin, and tropomyosin, remained unchanged. The steady-state level of SERCA phosphoenzyme intermediate was increased 2.5-fold, and the maximal velocity of Ca2+ uptake was increased 1.7-fold in TG hearts, demonstrating that the overexpressed protein is functional. Although the basal cytosolic calcium signal was decreased by 38% in TG cardiomyocytes, the amplitude of cytosolic calcium signal was increased by 71.8%. The rate of calcium resequestration was also increased in TG myocytes, which was reflected by a 51.6% decrease in the normalized time to 80% decay of calcium signal. This resulted in considerably increased peak rates of myocyte shortening and relengthening (50.0% and 66.6%, respectively). Cardiac functional analysis using isolated work-performing heart preparations revealed significantly faster rates of contraction and relaxation in TG hearts (41.9% and 39.5%, respectively). The time to peak pressure and the time to half-relaxation were shorter (29.1% and 32.7%, respectively). In conclusion, our study demonstrates that the SERCA1a pump can functionally substitute endogenous SERCA2a, and its overexpression significantly enhances Ca2+ transport and contractile function of the myocardium. These results also demonstrate that the SERCA pump level is a critical determinant of cardiac contractility.

Impact of M49, Mrp, Enn, and C5a peptidase proteins on colonization of the mouse oral mucosa by Streptococcus pyogenes

Resistance to phagocytosis is a hallmark of virulent Streptococcus pyogenes (group A streptococcus). Surface-bound C5a peptidase reduces recruitment of phagocytes to the site of infection, and hyaluronic acid capsules and/or the M protein limit the uptake of streptococci. In this study the relative impact of M and M-like proteins and the C5a peptidase on the virulence of a serotype M49 strain was assessed. The capacities of isogenic strains with an insertion mutation in emm49; with a deletion mutation in scpA49 (C5a peptidase gene); and with a deletion that removes all three M-like genes, mrp49, emm49, and enn49, to colonize mice and resist phagocytosis were compared. Experiments confirmed results obtained in an earlier study, which showed that the M49 protein was not required for in vitro resistance to phagocytosis, and also showed that the M protein was not required for colonization of mice. Failure to produce all three M-like proteins, M49, Mrp, and Enn49, significantly reduced the ability of these streptococci to resist phagocytosis in vitro but did not significantly alter the persistence of streptococci on the oral mucosa. In vitro experiments indicate that M+ streptococci are phagocytized by polymorphonuclear leukocytes that have been activated with phorbol-12-myristate 13-acetate or recombinant human C5a. This observation may explain the finding that expression of M49 protein is not essential for short-term colonization of the mouse oral mucosa.

Long-term efficacy of recombinant interferon alpha 2a in the treatment of chronic hepatitis C: a randomized prospective study comparing two dose schedules in Chinese patients

OBJECTIVE

To compare the long-term efficacy of a dose of 3 million units (MU) of r-IFN alpha 2a (IFN-alpha 2a) three times a week (t.i.w.) for 6 months with a starting dose 6 MU for 3 months and subsequent reduction to 3 MU t.i.w for further 3 months.

METHODS

Sixty-eight serological and histological chronic hepatitis C patients with elevated serum alanine aminotransferase (ALT) were enrolled and randomized into two groups. Sixty-three patients were completed with full course of treatment. Five patients were withdrawn from trial (2 due to personal reasons and 3 due to adverse drug reactions during treatment). Thirty patients received 6 MU IFN-alpha 2a t.i.w., 3 months followed by 3 MU t.i.w. for another 3 months (Group A). Thirty-three patients received 3 MU IFN-alpha 2a t.i.w. for 6 months (Group B).

RESULTS

The sex, age, baseline serum bilirubin, ALT and aspartate aminotransferase (AST) levels were matched in both groups. At the end of the 6th month, the complete and partial response rates in Group A were 60.0% and 16.7% respectively, and the clearance of serum HCV-RNA was 53.3%. In Group B, the complete and partial response rates were 72.7% and 6.1% respectively, and the clearance of HCV-RNA was 61.3%. The patients were followed up for 6, 12, and 18 months after stopping treatment. In Group A, the rates of complete normalization of ALT and clearance of serum HCV-RNA at 24 months were 50.0% and 60.0% respectively. In Group B, the rates of normalization of ALT and clearance of HCV-RNA at 24 months were 54.4% and 41.9% respectively. The efficacy between the two groups showed no statistically significant difference. The response rates of treatment were similar to those in the patients with HCV genotype 1b and 2a. Six patients (10.8% of the study population) developed neutralization antibodies to IFN-alpha 2a during treatment, and four of them were responded to the treatment. Adverse drug reactions (ADR), were common, but most of them were tolerable, and the incidence of ADR was in both groups, but the severity was higher in Group A.

CONCLUSIONS

IFN-alpha 2a is effective in the treatment of Chinese patients with chronic hepatitis C. The sustained response rates and adverse drug reactions among two dose schedule groups are similar.

Sarco(endo)plasmic reticulum Ca2+ ATPase isoforms and their role in muscle physiology and pathology

Recent studies suggest that SR Ca2+ transport function is altered in hypertrophied and failing myocardium. To understand whether alterations in SR Ca2+ ATPase levels affect myocardial contractility, we generated transgenic mice that specifically overexpress SERCA2a or SERCA1 pump in the mouse heart, using the cardiac alpha-MHC promoter. Analysis of SERCA2a transgenic mice show both an increase in mRNA and protein levels (120-150% of the wild type). Isolated work performing heart preparations revealed that SERCA2a mice have improved myocardial performance. On the other hand, SERCA1 overexpression in the heart resulted in isoform replacement without any change in total SERCA protein. Interestingly, SERCA1 transgenic hearts exhibited super contractility with a significant increase in rates of muscle contraction (+dp/dt) and relaxation (-dp/dT). The time to peak pressure and half-time to relaxation were significantly shorter.

Apolipoprotein E polymorphism in patients with Alzheimer's disease, vascular dementia and ischemic cerebrovascular disease

Apolipoprotein E sigma4 allele (ApoE sigma4) is associated with Alzheimer's disease (AD) in familial and sporadic cases, but the associations of ApoE sigma4 allele and vascular dementia (VD) and/or ischemic cerebrovascular disease (ICVD) are still controversial. To clarify the associations of ApoE polymorphism with AD, VD and ICVD in Japanese, we examined ApoE polymorphism in samples of 255 patients with AD, 87 patients with VD, and 123 patients with ICVD, as compared with 117 age-matched healthy control subjects (CTL). The frequency of the ApoE sigma4 allele was significantly higher in the VD group (0.21), the ICVD group (0.15) as well as in the AD group (0. 26) than in the CTL subjects (0.08). These findings suggest that the genotype of ApoE sigma4 is associated with not only AD but also VD and ICVD, and that ApoE sigma4 plays an important role in the development of dementia and ICVD.

Epidemiologic and genetic studies of dementia of the alzheimer type in japan

We carried out two separate epidemiological studies on long-term changes, 10 years apart, on the prevalence rate of dementia in the elderly by the same method for the same area in Japan. We also performed a genetic study of patients with dementia of the Alzheimer type (DAT) based on the epidemiological studies. The number of patients with dementia was much larger in 1990 than in 1980. Especially, the number of mildly demented patients was significantly larger in 1990 than in 1980. The 35 patients with DAT did not show any mutations of amyloid-beta protein precursor, presenilin 1 and presenilin 2 genes. The frequency of apolipoprotein E (apo E) sigma4 allele in DAT was significantly higher than that in control subjects (p < 0.005). This study suggests that the frequency of DAT may increase by aging of the population in the future and we confirm the close association between apoE sigma4 allele and DAT in a community-based study in Japan.

Co-expression of transforming growth factor beta and interferon tau during peri-implantation period in the ewe

The transforming growth factor beta (TGFbeta) family is known to control cell migration, growth, differentiation, function and regulation of extracellular matrix, all of which are required for the process of implantation. Expression of TGFbeta by the conceptus and endometrium was studied during the period of implantation in the ewe. A total of thirty-four ewes were hysterectomized on day 12, 14, 16, 18 or 20 of pregnancy (day 0 = day of estrus). Conceptus (200 mg wet weight) and endometrial (300 mg wet weight) tissues were cultured in vitro in 7 and 10 ml Eagle's minimal essential medium, respectively. The culture media were subjected to a bioassay to determine concentrations of TGFbeta. Conceptus culture media (CCM) were also analyzed for contents of ovine interferon-tau (oIFNr), low molecular weight acidic protein, produced by the trophectoderm between days 8 and 21 of pregnancy. Whole uteri including conceptus(es) and conceptuses (day 16) only were fixed and subjected to immunohistochemical and in situ hybridization studies. Levels of oIFNr produced by conceptuses were the highest on day 16 at 4.4 microg/ml. Concentrations of TGFbeta in day 12, 14, 16, 18 and 20 CCM were 38+/-19, 102+/-56, 862+/-152, 728+/-191 and 336+/-106 pg/ml, respectively, and approximately 90% of TGFbeta activity in CCM was due to TGFbeta1 whereas less than 10% was due to TGFbeta3 based on neutralization with TGFbeta subtype-specific antibodies. Immunohistochemical studies revealed that day 16 conceptuses displayed major staining for TGFbeta1, no beta2 staining and minor staining for beta3. In situ hybridization studies also revealed that day 16 trophectoderm possessed most TGFbeta1 mRNA while day 14 trophectoderm and day 20 chorion/amnion displayed weaker staining for TGFbeta1 mRNA. TGFbeta in day 12, 14, 16, 18 and day 20 endometrial culture media was 156+/-37, 129+/-33, 49+/-22, 62+/-23 and 179+/-40 pg/ml, respectively, and approximately 65% and 35% of the activities were due to TGFbeta1 and beta2, respectively. These results indicate that TGFbeta production by the conceptus coincides with the time when oIFNtau production starts to decline. These observations support the postulate that TGFbeta may play an important role in implantation in the ovine species.

Protein S-thiolation and redox regulation of membrane-bound glutathione transferase

Membrane-bound GST transferase (GSTm) occurs in hepatic microsomal and plasma membranes as well as in the outer mitochondrial membrane, and it is known to be activated by N-ethylmaleimide. We recently analysed the activation by GSSG in some detail. The approximately 5-fold stimulation is reversed upon reduction of GSSG by GSSG reductase. In steady-state experiments, the Kox value was determined to be 0.05, i.e. 20 times more GSSG than GSH produces half-maximal activation. Kox is independent of the total glutathione concentration, indicating that S-thiolation by mixed disulfide formation, rather than interchain or intrachain disulfide bridge formation, is responsible for activation. In Western blots, a 17.7 kDa band, in addition to the 17.3 kDa band, was detected upon treatment with GSSG or with GSH plus t-butyl hydroperoxide. We suggest that under oxidative stress, GSTm is activated through direct S-thiolation of the enzyme. Dethiolation occurs via thiol disulfide exchange governed by the cellular glutathione redox state.

[Purification and properties of inulinases from Aspergillus niger M89]

Four inulinase components were purified from Aspergillus niger M89 by (NH4)2SO4 fractionation, Sephadex G-200 gel filtration, DEAE-cellulose chromatography and polyacrylamide gel electrophoresis (PAGE). The molecular weight of EI EII EIII and EIV were indicated to be 102.6, 97.9, 62.5 and 36.5 kD respectively by SDS-PAGE. Measured by isoeleetric focusing, their isoelectric points were 4.15, 4.24, 4.48 and 4.15 respectively. Four forms of inulinase exibited maximal inulinase activity between 55-60 degrees C with optimal pH 4.0-5.0. There were some difference in their thermal stability. The little the molecule of the component was, the stronger its thermal stability was. All of four components were exo-acting inulinases.

Scavenger receptor class B type I as a mediator of cellular cholesterol efflux to lipoproteins and phospholipid acceptors

We recently reported that the rate of efflux of cholesterol from cells to high density lipoprotein (HDL) was related to the expression level of scavenger receptor class B type I (SR-BI). Moreover, the expression of this receptor in atheromatous arteries raises the possibility that SR-BI mediates cholesterol efflux in the arterial wall (Ji, Y., Jian, B., Wang, N., Sun, Y., de la Llera Moya, M., Phillips, M. C., Rothblat, G. H., Swaney, J. B., and Tall, A. R. (1997) J. Biol. Chem. 272, 20982-20985). In this paper we describe studies that suggest that the presence of phospholipid on acceptor particles plays an important role in modulating interaction with the SR-BI. Specifically, enrichment of serum with phospholipid resulted in marked stimulation of cholesterol efflux from cells that had higher levels of SR-BI expression, like Fu5AH or Y1-BS1 cells, and little or no stimulation in cells with low SR-BI levels, such as Y-1 cells. Stimulation of efflux by phospholipid enrichment was also a function of SR-BI levels in Chinese hamster ovary cells transfected with the SR-BI gene. Efflux to protein-free vesicles prepared with 1-palmitoyl-2-oleoylphosphatidyl-choline also correlated with SR-BI levels, suggesting that phospholipid, as well as protein, influences the interaction that results in cholesterol efflux. By contrast, cholesterol efflux from a non-cell donor showed no stimulation consequent to phospholipid enrichment of the serum acceptor. These results may help to explain observations in the literature that document an increased risk of atherosclerosis in patients with depressed levels of HDL phospholipid even in the face of normal HDL cholesterol levels.

Opposing effects of intracerebroventricularly injected norepinephrine on oxytocin and vasopressin neurons in the paraventricular nucleus of the rat

Our previous study shows that intracerebroventricularly (i.c.v.) injected norepinephrine (NE) had different effects on the discharge of different firing patterns of magnocellular neurons in the paraventricular nucleus (PVN). In the present study we further classified antidromically identified magnocellular neurons into two groups: vasopressin (VP) and oxytocin (OT) secreting neurons, and found that of all 48 cases of magnocellular neurons, NE had mainly excitatory effects on 36 cases of putatively OT-secreting neurons, and inhibitory effects on 12 cases of VP-secreting neurons. The third ventricular injected NE had almost the same effect on two types of neurons as that of lateral ventricular injection, partly ruling out the possibility that the lateral ventricularly injected NE may have acted indirectly on the magnocellular neurons in PVN. The results show that different mechanisms may be involved in mediating the effect of i.c.v. injected NE on VP- and OT-secreting neurons in the PVN.

[Primary studies on the establishment of cytomegalovirus murine model]

Intraperitoneal inoculation of Murine cytomegalovirus(MCMV) into Balb/C mice at age of 4 weeks resulted in acute MCMV infection of the mice. The infected mice had body weight reduction, growth retardation, salivary gland swelling and death. A lethal dose was 5 x 10(6) PFU/ml of MCMV. Virus could be recovered from salivary gland and the infectivity titer of MCMV reached to a high titer of 2 x 10(5) PFU/ml. Plaque formation of MCMV in 3T3/Swiss albino cells was identified. Histopathological examination showed the appearance of MCMV-specific intracytoplasmic inclusion bodies in neuron cells of the mouse brain.

[Cetyltrimethylammonium bromide fluorescence enhancement of aspirin]

The fluorescence intensities of aspirin with cetyltrimethylammonium bromide enhanced by micellar solutions have been examined. It is found that fluorescence enhancement depend on the concentration of CTAB and pH of solution.

Sexual knowledge, behaviors, and attitudes of medical students in Kunming, China

422 medical students at a conservative campus in Yunnan reported their sexual knowledge, behaviors, and attitudes of reproductive health service to help students acquire necessary sexual knowledge and avoid unwanted pregnancy, abortion, and sexually transmitted diseases.

[Application of VNTR D17S30 locus polymorphism in the paternity test]

A sensitive and rapid PCR-based technique was adopted to genotype the VNTR D17S30 locus. It was confirmed through the genetic analysis of 20 normal families that the inheritance of D17S30 locus coincides with Mendelian law as simple co-dominant. Retrospective analysis of 100 paternity cases demonstrated that D17S30 locus could be used in forensic paternity test in our country. The exclusion probability estimated from allele frequencies of D17S30 locus (74.04%) does not differ significantly from the observed rate of exclusion (80.00%) in these cases. In all excluded paternity cases there are two in which the exclusion evidence is solely provided by the D17S30 locus.

High affinity dimerization by Ski involves parallel pairing of a novel bipartite alpha-helical domain

c-Ski protein possesses a C-terminal dimerization domain that was deleted during the generation of v-ski, and has been implicated in the increased potency of c-ski in cellular transformation compared with the viral gene. The domain is predicted to consist of an extended alpha-helical segment made up of two motifs: a tandem repeat (TR) consisting of five imperfect repeats of 25 residues each and a leucine zipper (LZ) consisting of six heptad repeats. We have examined the structure and dimerization of TR or LZ individually or the entire TR-LZ domain. Using a quenched chemical cross-linking method, we show that the TR dimerizes with moderate efficiency (Kd = 4 x 10(-6) M), whereas LZ dimerizes poorly (Kd > 2 x 10(-5) M). However, the entire TR-LZ domain dimerizes efficiently (Kd = 2 x 10(-8) M), showing a cooperative effect of the two motifs. CD analyses indicate that all three proteins contain predominantly alpha-helices. Limited proteolysis of the TR-LZ dimer indicates that the two helical motifs are linked by a small loop. Interchain disulfide bond formation indicates that both the LZ and TR helices are oriented in parallel. We propose a model for the dimer interface in the TR region consisting of discontinuous clusters of hydrophobic residues forming "leucine buttons."

Effect of optic disc size or age on evaluation of optic disc variables

AIMS/BACKGROUND

It has been reported that the number of optic nerve fibres decrease with age, and the cup/disc (C/D) ratio increases as the optic disc size increases. Consequently, the normal value of the optic disc variables measured by an optic disc analyser may change according to the optic disc size or age. The effect of individual variations in optic disc size or age on interpretation of optic disc variables was investigated.

METHODS

Topographic optic disc variables of 104 normal Asian adults of both sexes aged 40 to 68 were measured using a confocal scanning laser ophthalmoscope (TopSS, Laser Diagnostic Technologies, Inc). Fourteen variables were evaluated according to the optic disc size or age. Statistical analysis was done by regression analysis.

RESULTS

With an increase in optic disc size, the increase in cup shape, effective area, 1/2 depth area, C/D ratio, neuroretinal rim area, volume above, volume below, and 1/2 depth volume were statistically significant (p < 0.05). However, contour variation, mean contour depth, average depth, maximum depth, average slope, and maximum slope were not affected (p > 0.1). Age did not have any significant influence on optic disc variables (p > 0.1).

CONCLUSION

Optic disc size, but not age, should be considered in the interpretation of optic disc variables.

Scavenger receptor BI promotes high density lipoprotein-mediated cellular cholesterol efflux

Scavenger receptor BI (SR-BI) binds high density lipoproteins (HDL) with high affinity and mediates the selective uptake of HDL cholesteryl ester. We examined the potential role of SR-BI in mediating cellular cholesterol efflux. In Chinese hamster ovary cells stably transfected with murine SR-BI, overexpression of SR-BI resulted in a 3-4-fold stimulation of initial cholesterol efflux rates. Efflux rates correlated with SR-BI expression in cells and HDL concentration in the medium. When incubated with synthetic cholesterol-free HDL, SR-BI-transfected cells showed approximately 3-fold increases in initial rates of efflux compared with control cells, indicating that SR-BI expression enhances net cholesterol efflux mediated by discoidal HDL. In six different cell types, including cultured macrophages, the rate of efflux of cholesterol mediated by HDL or serum was well correlated with cellular SR-BI expression level. In addition, in situ hybridization experiments revealed that SR-BI mRNA was expressed in the thickened intima of atheromatous aorta of apolipoprotein E knockout mice. Thus, SR-BI is an authentic HDL receptor mediating cellular cholesterol efflux. SR-BI may facilitate the initial steps of HDL-mediated cholesterol efflux in the arterial wall as well as later steps of reverse cholesterol transport involving uptake of HDL cholesterol in the liver.

[Effects of lanthanum and cerium on malignant proliferation and expression of tumor-related gene]

Cultured human gastric cancer cell line PAMC82 was studied in vitro to further verify anti-tumor effect sof rare-earth elements and explore their mechanism of tumor inhibition. Inhibitory effects of elements lanthanum and cerium on cell growth, reverse effects of them on reduction of malignancy and effects of them on level of expression of oncogene and cancer suppressor gene were observed. Lanthanum chloride, cerium chloride and mixed rare-earth chloride at levels of 0.5 to 1.5 mmol/L could inhibit obviously growth of cancer cells and change cell morphology and microtubule structure of PAMC82, similar to that of normal cells, their colony-forming ability lowered in soft agar, and expression of tumor suppressor gene p53, p16 and p21 increased and that of gene nm23 lowered.

[The prospective study of the influence of cytomegalovirus (CMV) infection of pregnant women to fetus]

Screening of CMV infection in 450 pregnant women in Shenyang was carried on by ELISA and PCR methods, and CMV infection was detected in 100 of their infants prospectively. The results were 97.11% of pregnant women with past infection, 0.89% with primary infection, 11.11% with recurrent infection, only 2% were susceptible. From 450 pregnant women, there were 3 infants with congenital defects and 3 abortions in active infective group, who were positive for IgM antibody, CMV DNA were positive in heparin peripheral blood, cervical secretion, placenta or amnionic fluid. The fetal infection rate and congenital defect rate in infective group were higher than that in inactive control group. Within 100 maternal-infant pair group, congenitally infected infants were 1.43 times higher in infective group than that in control group (RR = 1.43). Two infants with mental retardations (MDI<70) were born in infective group, but none in control group. In our study, primary infection of early pregnancy was most harmful to fetus, the intrauterine transmission rate was 33.3%. Among nine infected infants born from the infective group, two infants were with CID, and seven were symptomless. CMV screening is important for pregnant women in view of eugenic. When active CMV infection is found in early pregnancy, termination of pregnancy is better considered while CMV detection of amniotic fluid is also positive.

Intranasal immunization with C5a peptidase prevents nasopharyngeal colonization of mice by the group A Streptococcus

Early inflammatory events are initiated by phased production of C5a and interleukin-8 in tissue. Most serotypes of group A streptococci express a surface-bound peptidase (SCPA) which specifically cleaves mouse and human C5a chemotaxins. This study investigates the impact of SCPA on colonization of the nasopharyngeal mucosa of mice and evaluates its potential to induce protective immunity. Two strains, serotypes M6 and M49, which contain insertion and deletion mutations in the SCPA gene (scpA) and represent the two major subdivisions of group A streptococci, were characterized and compared in a mouse intranasal infection model. In this model, SCPA mutants were more rapidly cleared from the nasopharynges of inoculated mice compared with wild-type strains. A 2,908-bp fragment of scpA49 gene, obtained by PCR, was ligated to the expression vector pGEX-4T-1 and expressed in Escherichia coli. The affinity-purified deltaSCPA49 protein proved to be highly immunogenic in mice and rabbits. Although the purified deltaSCPA49 immunogen lacked enzymatic activity, it induced high titers of rabbit antibodies which were able to neutralize peptidase activity associated with M1, M6, M12, and M49 streptococci in vitro. This result confirmed that antipeptidase antibodies lack serotype specificity. Intranasal immunization of mice with the deleted form of the SCPA49 protein stimulated significant levels of specific salivary secretory immunoglobulin A (IgA) and serum IgG antibodies and reduced the potential of wild-type M1, M2, M6, M11, and M49 streptococci to colonize. These experiments suggest a new approach to vaccine development for prevention of streptococcal pharyngitis.

[Studies on peripheral blood stem cells mobilization by short course and high-dose G-CSF]

OBJECTIVE

To explore the effect of short-course, high dose granulocyte-colony stimulating factor (G-CSF) on peripheral blood stem cell (PBSC) mobolization.

METHODS

G-CSF 5microg/kg was injected subcutaneously twice daily for 3 consecutive days. On the first day and the fourth day the peripheral blood and bone marrow were collected for CFU-GM, BFU-E, CFU-mix assays and CD34/CD38 detection. A single apheresis of over 8000ml blood processing was performed with CS-3000 blood cell separator. The mononuclear cells were prepared for hematopoietic colony assays and CD34/CD38 detection before and after freezing.

RESULTS

After adminitration of G-CSF, the white blood cell count increased significantly. The CFU-GM, BFU-E, CFU-mix yields and CD34+ CD38+ cell and CD34+ CD38- cells also increased significantly (P<0.05). The median of mononuclear cells was 1.56 x 10(8)/kg. After one week freezing, the recovery of mononuclear cells, CFU-GM, BFU-E yields and CD34+ CD38+ cells were about 80% (P>0.05) and CFU-mix yields was 60%; The CD34+ CD38- cells were decreased compared with that of pre-freezing (P<0.05). The median of the reinfused mononuclear cells was 1.27 x 10(8)/kg,CFU-GM 6. 7 x 10(4)/kg, BFU-E 1.6 x 10(4)/kg, CFU-mix 0.32 x 10(4)/kg, CD34- CD38+ cells 1.6 x 10(6)/kg and CD34+ CD38- cells 0.23 x 10(6)/kg.

CONCLUSION

Short course and high-dose G-CSF can effectively mobilize the peripheral stem cells. The mononuclear cells, hematopoietic colonies and CD34/CD38 cells were satisfied for the peripheral stem cells rescue.

Photorefractive properties of iron-doped stoichiometric lithium niobate

The photorefractive properties of stoichiometric LiNbO(3) crystals with a small number of defect densities grown by the double-crucible Czochralski method are investigated and compared with the defect densities of commercially available congruent Fe-doped LiNbO(3) crystals. Two-wave-mixing experiments show that novel stoichiometric crystals exhibit larger photorefractive gain and considerably faster response times than congruent ones. The results indicate that the nonstoichiometry defect control of photorefractive crystals is of key importance for the improvement of their properties.

Familial occurrence of hemangioblastoma of central nervous system

OBJECTIVE

To study the familial occurrence of hemangioblastoma of the central nervous system and to search for an effective way to diagnose and manage the disease.

METHODS

From 1974 to 1993, six patients with hemangioblastoma with family history underwent surgical treatment at our hospital. Computerized tomography (CT) or magnetic resonance imaging (MRI) technique was used for the diagnoses before operation.

RESULTS

Each patient had more than two relatives with hemangioblastoma. Multiple lesions were found in two of the six familial hemangioblastoma cases. All the patients recovered well after operation. So far, no victims have been discovered in the third generation.

CONCLUSIONS

The high occurrence rate of familial hemangioblastoma cases suggests an involvement of hereditary factors. We need a long follow-up study on the descendants of familial hemangioblastoma patients. MRI is of diagnostic value in determining the location and nature of hemangioblastoma in both brain and spinal cord. A thorough examination is necessary for hemangioblastoma patients, and microsurgery is important in removing the tumor.

Use of meiotic FISH for identification of a new monosome in Gossypium hirsutum L

The extensive use of molecular cytogenetics in human genetics and clinical diagnostics indicates that analogous applications in plants are highly feasible. One sort of application would be the identification of new aneuploids, which traditionally involves either direct karyotypic identification, which is feasible in only a few plant species, or tests with markers (cytogenetic, genetic, or molecular), which require sexual hybridization and at least one subsequent seed or plant generation. We have used meiotic fluorescence in situ hybridization (FISH) to analyze a new monosome of cotton (Gossypium hirsutum L., 2n = 4x = 52, 2(AD)1) that had a phenotype which seemed to be distinct from monosomes in the Cotton Cytogenetic Collection. Painting with A2-genome DNA revealed the monosome's D-subgenome origin. DAPI-PI staining showed that the monosome carries a major NOR, delimiting it to the major NOR-bearing chromosomes of the D-subgenome, i.e., 16 or 23. Dual-color FISH with 5S and 18S-28S rDNAs indicated that the monosome contains separate major clusters of each of these two tandemly repeated rDNA elements, thus delimiting the monosome to chromosome 23, for which the Cotton Cytogenetic Collection has previously been devoid of any sort of deficiency. Of the 26 chromosomes in the cotton genome, the Collection now provides coverage for 16 (70%) in the form of monosomy, and 20 (77%) in the form of monosomy and (or) telosomy. Use of molecular cytogenetic methods to identify a new plant aneuploid in cotton exemplifies the fact that a physicochemical karyotypic chromosome identification system is not required a priori for application of new molecular cytogenetic methods, thus indicating their potential applicability to nearly all plant species.

Subunit specificity and organ distribution of glutathione transferase-catalysed S-nitrosoglutathione formation from alkyl nitrites in the rat

Glutathione transferase (GST)-catalysed S-nitrosoglutathione (GSNO) formation from alkyl nitrites was determined with the homodimers 1-1, 2-2, 3-3, and 4-4 isolated from rat liver. The 4-4 isoform showed a high specificity for the alkyl nitrites. Total GST activities were studied in homogenates from different organs. The liver showed highest GST activity both with amyl nitrite and with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate, the activity ratio of amyl nitrite over CDNB being 3.8. In lung and heart, these ratios were 6.2 and 5.7, respectively, indicating a selectivity of these organs for alkyl nitrite metabolism and GSNO formation.

Protein engineering on subtilisin E

Protein engineering was carried out by site-directed and random mutagenesis on subtilisin E gene. Four mutants were obtained. They are M222A; M222A, N118S; M222A, N118S, Q103R; and M222A, N118S, Q103R, D60N. The mutant genes were recombined in pBE-2, an E. coli-B. subtilis shuttle vector, and transformed into B. subtilis DB104, an alkaline and neutral proteinase deficient strain. The subtilisin E mutations obtained from their gene expressions were purified. The properties of these mutants showed that the M222A mutation made the enzyme resistant to oxidation, N118S mutation increased the thermal stability, while Q103R and D60N mutations enhanced the specific activity of the enzyme but decreased the thermal stability and, in particular, D60N mutation caused the enzyme to be very unstable. The IEF-PAGE showed that the wild type and M222A mutant had the same pI of 8.92, while those of double mutant, triple mutant, and quadruple mutant were 8.88, 9.10, and 9.17, respectively. The optimum pH range was 7.5-9.5 for suc-AAPF-pNA substrate and was 10-12 for casein substrate.

Characterization of the tumor invasion area in the rat intracerebral glioma

Tumor cell invasion surrounding intracerebrally implanted tumors in rats was studied by comparing the results of cerebral microangiography, fluorescence imaging of blood-brain barrier (BBB) disruption and histopathology. Each comparison was on subsequent sections taken from an initial 1 mm coronal slice of brain taken through the cell injection site containing tumor using the RT-2 glioma model. Tumor extension was assessed at 3, 5, 7 and 9 days after tumor implantation. Analysis of the brain adjacent to tumor shows that the actual tumor cell invasion area is greater than the area of BBB disruption at later stages of tumor growth and the extent of tumor vascularization lies well within the area defined by the extent of tumor cell invasion. Furthermore, this study found that the size of the area of tumor cell invasion remains relatively stable in proportion to the solid tumor mass at various stages of growth such that the area of tumor invaded brain was approximately 2.5 times greater than the area outlined by solid tumor mass. We conclude that measurement of the solid tumor mass, tumor vascular area and region of blood-brain barrier disruption due to tumor, grossly underestimate the total tumor volume. Therapies aimed at controlling glial tumor growth must, therefore, include normal appearing regions of brain peripheral to the abnormal region defined as tumor and tumor invaded brain as defined by radiographic and imaging studies.

[High-dose chemotherapy supported by peripheral blood stem cells to treat intermediate--and high-grade non-Hodgkin's lymphomas]

In this study, 16 eligible patients with intermediate and high-grade non-Hodgkin's lymphoma were treated with a new high-dose DHACT regimen supported by rhG-CSF and peripheral blood stem cell (PBSC) rescue. PBSC were mobilized by rhG-CSF or rhGM-CSF. Single leukapheresis was performed and the PBSC were then frozen in liquid nitrogen. CFU-GM clonogenic assay for mononuclear cells and resuscitated progenitor cells done to calculate how many progenitor cells were alive after freezing. The DHACT chemotherapy was composed of carboplatin 600 mg/m2 on d1, Ara-C 1500 mg/m2 on d2, VM-26 100 mg/m2 on d3, 4, and dexamethasone 40 mg/d, on d1-4. Autologous PBSC was reinfused after 24 to 48 hours of chemotherapy. Recombinant human G-CSF at 300 micrograms administered daily on 2 successive days when the absolute neutrophil count was greater than 1 x 10(9)/L. Other supportive care procedures were standard for the unit. The median amount of PBSC reinfused into a patient was 0.9 x 10(8)/kg. The recovery rate of CFU-GM was 78% after cryopresevation. Within 7 to 9 days after high-dose DHACT chemotherapy, the WBC count and the platlet count arrived nadir, and then rose gradually with rhG-CSF injection. The median time for WBC count from nadir to > or = 1 x 10(9)/L was 4 days, and that for platelet count from nadir to > or = 50 x 10(9)/L was 7 days. Nine patients achieved complete remission and 5 patients achieved partial remission. The median follow-up on survival was 9 months. High-dose DHACT regimen supported by rhG-CSF and PBSC rescue is a safe and effective treatment for patients with advanced intermediate and high-grade non-Hodgkin's lymphoma.

Presenilin-1 polymorphism in patients with Alzheimer's disease, vascular dementia and alcohol-associated dementia in Japanese population

We investigated the genetic association between intronic polymorphism in Presenilin-1 (PS-1) gene and patients with various types of dementia such as Alzheimer's disease (AD), vascular dementia (VD) and alcohol associated dementia (ALD), in Japanese population. Homozygosity for allele 1 of the PS-1 polymorphism was significantly increased in late-onset sporadic AD, but not in early-onset sporadic AD, familial AD, VD and ALD. When late-onset sporadic AD patients were divided on the basis of apolipoprotein E (APOE) genotype, homozygosity for the allele 1 of the PS-1 polymorphism was significantly increased in patients with late-onset sporadic AD without APOE epsilon 4 allele, but not in those with APOE epsilon 4 allele. Intronic mutation in PS-1 gene may be specific and one of the genetic risk factor for late-onset sporadic AD.

Role of intracardiac angiotensin II in cardiac dysfunction of rat during septic shock

OBJECTIVE

To observe changes in the content of myocardial angiotensin II and its role in cardiac dysfunction of rat during septic shock.

METHODS

Septic shock model was produced by cecal ligation and puncture (CLP) operation on rats. Experimental rats were given captopril 15 mg.kg-1/d per os for 3 days before CLP operation. Mean blood pressure and left ventricular pressure were recorded. Myocardial angiotensin converting enzyme (ACE) activities were determined by a fluorometric assay and myocardial angiotensin II content was measured by radioimmunoassay. Highly purified membrane of sarcoplasmic reticulum (SR) was prepared from rat hearts. Assays were made of ATP-dependent Ca2+ uptake by cardiac SR and (3H) ryanodine binding to SR.

RESULTS

Myocardial angiotensin II content increased by 51.5% (P < 0.01) at the 18th hour post CLP, meanwhile there was a decrease in left ventricular +/- dp/dtmax value and the impairment in Ca2+ uptake and (3H) ryanodine binding to cardiac SR. Preliminary administration of captopril reduced myocardial ACE activity and angiotensin II content, but increased left ventricular +/- dp/dtmax value. In comparison to shock group, the initial rate and the capacity of SR Ca2+ uptake were increased by 120% (P < 0.01) and 33.9% (P < 0.05), the Bmax value of (3H) ryanodine binding to SR was also elevated, while the Kd value remained unchanged.

CONCLUSIONS

The elevated intracardiac angiotensin II, resulting from the activation of myocardial ACE during sepsis, probably serves as one of the important mediators participating in the pathogenesis of heart failure: the effects of angiotensin II may be associated with the disturbance of Ca2+ transport function of cardiac SR.