[Determination of the polymorphism of DXS102 locus and its application in gene diagnosis]

OBJECTIVE

To determine the polymorphism of DXS102 and use it in gene diagnosis in hemophilia B.

METHODS

Amp-FLP and linkage analysis on 234 chromosomes.

RESULTS

Eight alleles were found at DXS102 locus. The number of AC dinucleotide repeats ranged from 13 to 21. And the observed heterozygosity, calculated heterozygosity and polymorphism information content(PIC) were 0.87, 0.80 and 0.80, respectively. It was noted that the difference of the allele frequencies of DXS102 in Chinese and European populations was significant. By using the linkage analysis of the DXS102 locus, a family with a hemophilia B patient receiving gene therapy in 1994 was analyzed and a carrier in that family was then detected.

CONCLUSION

The polymorphism of DXS102 locus reveals significant difference between Chinese and European populations. DXS102 locus can be used as a promising marker for gene diagnosis in hemophilia B family.

Purification, characterization, and cloning of enamel matrix serine proteinase 1

The maturation of dental enamel succeeds the degradation of organic matrix. Inhibition studies have shown that this degradation is accomplished by a serine-type proteinase. To isolate and characterize cDNA clones encoding this proteinase, we used two degenerate primer approaches to amplify part of the coding region using polymerase chain-reaction (PCR). First, we purified the proteinase from porcine transition-stage enamel matrix and characterized it by partial protein sequencing. The enzyme was isolated from the neutral soluble enamel extract by successive ammonium sulfate precipitations, hydroxyapatite HPLC, reverse-phase HPLC, DEAE ion exchange, and affinity chromatography with a Benzamidine Sepharose 6B column. The intact protein and lysylendopeptidase-generated cleavage products were characterized by amino acid sequence analyses. Degenerate oligonucleotide primers encoding two of the polypeptide sequences were synthesized. In a complementary strategy, degenerate oligonucleotide primers were designed against highly conserved active-site regions of chymotrypsin-like proteinases. Both approaches yielded PCR amplification products that served as probes for screening a porcine enamel organ epithelia-specific cDNA library. The longest full-length clone is 1133 nucleotides and encodes a preproprotein of 254 amino acids. We designate this protein enamel matrix serine proteinase 1 or EMSP1. The active protein has 224 amino acids, an isotope-averaged molecular mass of 24.1 kDa, and an isoelectric point of 6.0. Multiple-tissue Northern analysis indicates that EMSP1 is a tooth-specific protein. Gelatin enzymography shows a dramatic increase in EMSP1 activity in the transition-stage enamel matrix. EMSP1 is most homologous to kallikriens and trypsins.

[Lasting expression of hF IX mediated by myoblasts in mice]

OBJECTIVE

To develop experimentally gene therapy for hemophilia B by using C2C12 cells and C3H mice as models.

METHODS

The retroviral vector containing MCK enhancer and hCMV promoter was constructed and was used to transfect PA317 cells. Then the viral particles were used to transfect C2C12 cells and select the G418r clones,which were further confirmed by Southern, Northern, Western blots. And then the C2C12 cells expressing hF IX protein were injected into C3H mice and hF IX expression in vivo was studied.

RESULTS

The expression level of hF IX in vivo was positively correlated with the number of injected cells, and the in vitro expression level of these cell clones. The expression of hF IX could be enhanced and prolonged by immunosuppressive agents.

CONCLUSION

Allogeneic myoblasts transplantation leads to immunorejection, but repeated injections at a longer intervals could improve the existing rate of transplanted cells. And this might be helpful to gain insight into the myoblast-mediated gene therapy for hemophilia B patients.

[Endometrial cytology in normal postmenopausal women and during hormone replacement therapy]

OBJECTIVE

To explore the possibility of endometrial cyopathologic examination as a method of monitoring endometrium during hormone replacement therapy (HRT) in postmenopausal women.

METHODS

Endometrial cells were taken via tubal aspiration in 60 normal postmenopausal women (non-HRT group) and 41 with HRT for 3-18 months (HRT group). Their morphologic changes were observed and compared by cytopathologist.

RESULTS

Atrophic endometrium was found in 51.7% of the non-HRT group. Its proportion increased with age and the time after menopause. Macrophages were seen in 68.3% of this group. However, in the HRT group the occurrence of atrophic type and macrophage (12.2%, 7.0% respectively) was significantly lower than that in the non HRT group (P < 0.05). Heterogeneity of endometrial cell type was shown both in non-HRT (38.3%) and HRT (65.8%) groups.

CONCLUSIONS

Endometrial cells of postmenopausal women are not always atrophic in appearance. They change significantly during HRT. Endometrial cytological examination may be useful for monitoring during HRT.

[DNA polymorphism analysis by capillary electrophoresis]

A review is given here to describe the principle and methods of gene polymorphism analysis by capillary electrophoresis (CE). DNA length polymorphism and sequence polymorphism are very important phenomena in gene molecular biology. Some practical works of gene length polymorphism analysis and sequence polymorphism analysis are listed. SSCP and HPA methods detecting gene point mutations are demonstrated. Applications of gene polymorphism analysis by CE in clinical, forensic and biological research are also discussed in this paper.

Localization of the domains involved in ligand binding and activation of the glucose-dependent insulinotropic polypeptide receptor

The receptors for the two structurally related insulinotropic hormones Glucose-dependent Insulinotropic Polypeptide (GIP) and Glucagon-Like Peptide-1 (GLP-1) share approximately 40% sequence identity and demonstrate complete specificity for their endogenous ligands, while utilizing similar second messenger pathways. In the current study chimeric GIP-GLP-1 receptors were prepared, and the effect of domain-exchange on ligand binding and adenylyl cyclase activation examined. A chimera (CH-2) consisting of the first 132 amino acids of the external N-terminal (NT) domain bound 125I-GIP with high affinity (27.77 +/- 11.85 nM). However, for receptor coupling to cAMP production it was necessary to extend the NT into the first transmembrane (TM-1) region (CH-3: IC50 = 9.04 +/- 1.07 nM; EC50 = 17.1 +/- 3.5 nM). A chimera which included part of TM-3 (CH-4) demonstrated binding and signalling (IC50 = 8.33 +/- 0.14 nM; EC50 = 467.5 +/- 173.6 pM) similar to the wild type receptor (IC50 = 1.33 +/- 0.19 nM; EC50 = 497.9 +/- 211.7 pM). Surprisingly constructs CH-2 and CH-3, while devoid of detectable 125I-GLP-1 binding, were capable of eliciting GLP-1-specific cAMP production (EC50s CH-2 = 81.4 +/- 19.6 nM; CH-3 = 5.99 +/- 0.68 nM) suggesting that receptor activation is not completely dependent on high affinity receptor binding. These data clearly demonstrate that the NT domain of the GIP receptor acts as the ligand-specific binding domain and that the first transmembrane domain is important for receptor activation.

Association between lactation length and sow reproductive performance and longevity

OBJECTIVE

To determine whether lactation length was associated with reproductive performance or longevity of sows.

DESIGN

Cohort study.

SAMPLE POPULATION

Data collected between 1986 and 1992 for sows in 15 breeding herds in Minnesota and Iowa.

PROCEDURE

Sows were grouped into 4 genetic line categories according to their sources and 6 parity categories (1, 2, 3, 4, 5 or 6, and > or = 7). Multivariate regression analysis of reproductive performance was conducted, using the general linear model procedure Logistic regression was conducted with a dichotomous response variable for sow longevity (ie, removal from or retention in the herds). Odds ratios were obtained from estimated coefficients of the regression.

RESULTS

Herd, genetic line, parity, year, month, and lactation length were significant in statistical models for litter (eg, number of live pigs/litter) and interval (eg, weaning-to-mating interval) traits. Interactions between lactation length and year, lactation length and genetic line, lactation length and parity, and lactation length and genetic line and parity were also significant. Sows removed from herds had a significantly shorter lactation length than did sows of the same parity that were retained in the herds. Sows that had shorter lactation lengths were at higher risk of being removed from the herds than were those that had longer lactation lengths.

CLINICAL IMPLICATIONS

Lactation length is associated with reproductive performance and longevity, but genetic line and parity play a role as well. Thus, attention should be paid to genetic lines and parity of sows in the herd when implementing an early weaning production practice.

[The study of DSX-I type microcomputer autometic control injector system]

This paper studies the propulsive force of injector system controlled by 8031 single-chip microcomputer for Medical use By using one 8031 single-chip microcomputer as a microprocessor, the minimal autometic control system is constructed, which turns real-time control into reality. This product is a modern appliance used in diagnostic imaging medicine, in design of which the advanced instrument and electrical machinery are integrated into a unified structure. The clinic data demonstrate that the contrast medium can be injected to patients with rapidly and evenly. Dynamic CT Scanning can be intensified at any site of the body. x-ray dose exposed and lobour intensity to the operator can be decreased greatly, raise working efficiency.

Molecular cloning and mRNA tissue distribution of a novel matrix metalloproteinase isolated from porcine enamel organ

A cDNA encoding a novel matrix metalloproteinase (MMP) was isolated from a porcine enamel organ-specific cDNA library. Multiple tissue northern blot analysis revealed the presence of two mRNA transcripts which were expressed only in the enamel organ. The transcripts were 1968 bp or 3420 bp in length and resulted from the utilization of alternative polyadenylation sites. The open reading frame of the cloned mRNA encodes a protein composed of 483 amino acids. The MMP has a predicted molecular mass of 54.1 kDa, which is similar to that of the stromelysins or collagenases, although it is not a member of either of these two classes of MMPs. A motif analysis revealed that the cloned MMP does not contain a consensus hemopexin-like domain because it lacks a critical tryptophan and proline residue at the appropriate positions. Since the cloned MMP is a new member of the MMP gene family and its expression appears limited to the enamel organ, we have named it enamelysin.

Breed differences in boar taint: relationship between tissue levels boar taint compounds and sensory analysis of taint

A total of 228 intact male pigs form Duroc, Hampshire, Landrace, and Yorkshire breeds were used in the experiment. Samples of salivary gland and backfat were collected at slaughter for colorimetric assay of salivary and fat 16-androstene levels and fat skatole levels. Fat levels also were tested by a sensory panel using an R-index technique for detecting the presence of boar taint. The proportion of tainted carcasses determined by the sensory panel was 5.0% for androstenone and 11.4% for skatole, with a combined total of 15.0% tainted from either source. Sensory analysis of taint showed a lower proportion (P < .05) of tainted carcasses in Hampshire, with no difference in taint across the other three breeds. Analysis of taint compounds indicated that overall 14.5% of pigs had salivary gland 16-androstene levels and 20.9% had fat 16-androstene levels above acceptable limits. There was a higher (P < .05) proportion of Duroc pigs above the threshold levels for 16-androstenes in both salivary gland and fat. Landrace pigs had the lowest (P < .05) average tissue concentrations of steroids and skatole. Across breeds, only 1.8% of pigs had fat skatole concentrations above .25 ppm, which has been suggested as threshold levels of skatole for taint. The canonical correlation coefficient between fat compound levels and the R-indices of fat 16-androstenes and skatole was .40 (P < .001). Our results indicate breed differences in tissue levels of taint compounds and in taint assessed by a sensory panel. Levels of 16-androstene steroids were highly associated with taint, but more pigs had measured levels above the threshold than those identified as tainted by sensory analysis. Levels of fat skatole were low overall and did not account for all the pigs judged as tainted from skatole by sensory analysis.

[Transurethral noncontact laser ablation of the large prostate]

42 cases of the large benign hypertrophy of the prostate were treated by transurethral noncontact laser ablation. The results of the patients followed up no less than six months and treatment were reported. The technique of the procedure and its related problems were described and our experience was presented. If we use the technique of the procedure skill fully, noncontact laser ablation of large benign hypertrophy of the prostate is safe and effective.

Particulate air pollution and respiratory disease in Anchorage, Alaska

This paper examines the associations between average daily particulate matter less than 10 microns in diameter (PM10) and temperature with daily outpatient visits for respiratory disease including asthma, bronchitis, and upper respiratory illness in Anchorage, Alaska, where there are few industrial sources of air pollution. In Anchorage, PM10 is composed primarily of earth crustal material and volcanic ash. Carbon monoxide is measured only during the winter months. The number of outpatients visits for respiratory diagnoses during the period 1 May 1992 to 1 March 1994 were derived from medical insurance claims for state and municipal employees and their dependents covered by Aetna insurance. The data were filtered to reduce seasonal trends and serial autocorrelation and adjusted for day of the week. The results show that an increase of 10 micrograms/m3 in PM10 resulted in a 3-6% increase in visits for asthma and a 1-3% increase in visits for upper respiratory diseases. Winter CO concentrations were significantly associated with bronchitis and upper respiratory illness, but not with asthma. Winter CO was highly correlated with automobile exhaust emissions. These findings are consistent with the results of previous studies of particulate pollution in other urban areas and provide evidence that the coarse fraction of PM10 may affect the health of working people.

Intercommunity differences in acid aerosol (H+)/sulfate (SO4(2-) ratios

Exposures to acid aerosols have been associated with acute and chronic health effects. Beginning in 1988, extensive monitoring of acid aerosols (H+), sulfates (SO4(2-)), and ammonia (NH3) was conducted in 24 communities in the United States and Canada in order to characterize the seasonal and daily variations of these pollutants. More recently, in 1992 and 1993, summer monitoring of the same pollutants was conducted by Harvard researchers at multiple locations in Philadelphia, Pennsylvania to examine the factors causing spatial variation in the acidity levels in the greater metropolitan Philadelphia area. Earlier, a similar study also was conducted by Harvard in a more rural community, State College, Ohio, providing data on acidity, sulfate, and ammonia levels. In addition to these studies, New York University researchers have gathered substantial data on aerosol acidity, sulfates, and NH3 levels from sites in the New York City metropolitan region, Albany, Buffalo, and the Toronto metropolitan region between 1988 and 1992. This paper examines the relationships among H+, SO4(2-), ozone, and population density using summer measurements from sites in 24 cities across the United States and Canada, as well as Philadelphia, State College, the New York City region, Buffalo, and Albany. While past studies have consistently shown that H+ and SO4(2-) are correlated over time at sites in eastern North America, the results of our analysis show that spatial variations in the ratios of mean acid-to-sulfate levels also can be predicted satisfactorily with the use of either a linear or a quadratic model, once variations in population density are addressed (R2 = 0.6). These models may be useful in retrospective epidemiological investigations of acid aerosol exposures and health effects, using widely available sulfate measurements and data on local population size.

Personal exposure to airborne particles and metals: results from the Particle TEAM study in Riverside, California

The PTEAM Study was the first large-scale probability-based study of personal exposure to particles. Sponsored by the U.S. Environmental Protection Agency (EPA) and the Air Resources Board of California, it was carried out by the Research Triangle Institute (RTI) and the Harvard University School of Public Health (HSPH). HSPH designed and constructed a 4-lpm, battery-operated personal monitor for inhalable particles (PM10) that could be worn comfortably for up to 14 hours by persons from 10 to 70 years old. The monitor was worn for two consecutive 12-hour periods (day and night) during the fall of 1990 by 178 participants representing 139,000 nonsmoking residents of Riverside, California. Nearly identical monitors were employed to collect concurrent indoor and outdoor samples. The monitors were equipped with a different sampling nozzle to collect fine particles (PM2.5). Population-weighted daytime personal PM10 exposures averaged 150 +/- 9 (SE) micrograms/m3, compared to concurrent indoor and outdoor concentrations of 95 +/- 6 micrograms/m3. This suggested the existence of excess mass near the person, a "personal cloud" that appeared related to personal activities. Fourteen of 15 prevalent elements also were evaluated in the personal samples. The two major indoor sources of indoor particles were smoking and cooking; even in these homes, however, more than half of the indoor particles came from outdoors, and a substantial portion of the indoor particles were of undetermined indoor origin. Outdoor concentrations near the homes were well correlated with outdoor concentrations at the central site, supporting the idea of using the central site as an indicator of of ambient concentrations over a wider area. Indoor concentrations were only weakly correlated with outdoor concentrations, however, and personal exposures were even more poorly correlated with outdoor concentrations. Elemental profiles were obtained for environmental tobacco smoke (ETS) (major contributions from potassium and chlorine) and cooking emissions (aluminum, iron, calcium, and chlorine). These profiles can be used in future source apportionment studies.

Determination of polyamines in serum by high-performance capillary zone electrophoresis with indirect ultraviolet detection

A method for determining polyamines in serum by capillary zone electrophoresis (CZE) with indirect ultraviolet detection was established. The concentrations of polyamines in the sera of six healthy adults were determined and the results were in accordance with those obtained previously by high-performance liquid chromatography (HPLC). However, the CZE method is superior to HPLC in that it has high sensitivity, small sample consumption and easy sample pretreatment.

The unusual 5' splicing border GC is used in myrosinase genes of the Brassicaceae

Myrosinase (thioglucosidase glucohydrolase; EC 3.2.3.1) is a group of isoenzymes in the Brassicaceae, which hydrolyze glucosinolates. Genes encoding myrosinase contain 12 exons and 11 introns. Sequence comparison of two myrosinase genes from Arabidopsis thaliana, TGG1 and TGG2, with the corresponding cDNA from leaves, showed preferential use of a GC dinucleotide as the 5' splicing border in intron 1 instead of an adjacent GT dinucleotide four bp further 3'. This 5' GC splice site is conserved in all seven myrosinase genes characterized from three different species. Likewise, in the 3' region of intron 1 two AG dinucleotides are located seven bp apart. Only the most 5' of these dinucleotides was found to be used in splicing. Sequence analyses of TGG1 cDNA isolated from seeds, siliques and vegetative tissue using reverse transcription PCR showed that the splicing pattern of this intron is identical in these tissues for TGG1. The GT and the most 3' AG dinucleotides mentioned above have been assumed to be the intron borders of intron 1 in several myrosinase genes. The present investigation shows that this assumption is not correct.

A population-based exposure model for benzene

A model of daily-average inhalation exposures and total-absorbed doses of benzene to members of large populations was developed as part of a series of multimedia exposure and absorbed dose models. The benzene exposure and dose model is based upon probabilistic rather than sequential simulation of time-activity patterns, a simpler approach to modeling personal benzene exposures than other existing models. An important innovation of the benzene model is the incorporation of an anthropometric module for generating correlated exposure factors used to estimate absorbed doses occurring from inhalation, ingestion, and dermal absorption of benzene. A preliminary validation exercise indicates that the benzene model produces reasonable estimates of the distribution of benzene personal air concentrations expected for a large population. Uncertainty about specific percentiles of the predicted distributions of personal air concentrations was found to be dominated by uncertainty about microenvironmental benzene concentrations rather than time-activity patterns, and uncertainty about total absorbed doses was dominated by a lack of knowledge about the true absorption coefficient for benzene in the lung rather than knowledge gaps about microenvironmental concentrations or intake rates. The results of this modeling effort have implications for environmental control decisions, including evaluation of source control options, characterization of population and individual risk, and allocation of resources for future studies.

Regulation of human clotting factor IX cDNA expression in transgenic mice

To study the expression of human clotting factor IX cDNA in transgenic mice, which is an essential work on gene therapy for hemophilia B, 3 recombinant constructions containing different lengths of human clotting factor IX cDNA have been introduced into the cultured cells. All of the recombinant constructions were found to be expressed well in vitro. They were then microinjected into the male pronuclei of the fertilized mouse eggs respectively for generating transgenic mice. Unfortunately, none of them was expressed in any transgenic mice. These results show that the expression of the human clotting factor IX cDNA in the transgenic mice can be determined by cis regulatory element(s). As compared with the results from other related works, it is suggested that the cis regulatory element(s) is resided in the 5'-end non-coding region.

Construction and high expression of retroviral vector with human clotting factor IX cDNA in vitro

The construction of the high titer and highly expressed safety retroviral vector carrying human clotting factor IX cDNA is reported. Retroviral vectors LNCIX, LIXSN and LCIXSN, driven by hCMV, LTR and hCMV combined with LTR promoter respectively, were constructed, based on the retroviral vector LNL6, and transferred into packaging cell line PA317 with electroporation. Human clotting factor IX was detected in the cultured cells transduced with LNCIX and LIXSN but not in the cells transduced with LCIXSN. The viral titer of PA317/LNCIX was 800,000 CFU per mL. With ELISA detection, it was found that the cells transduced with this vector can express human clotting factor IX at the level of 3.3 micrograms per 10(6) cells in 24 h in human fibrosarcoma cells HT-1080 and 2.5 micrograms per 10(6) cells in 24 h in hemophilia B patients' skin fibroblast HSF cells, and more than 80% of them were biologically active. The viral titer and expression of human FIX were increased, and the construction of retroviral vector backbone was improved and the safety was guaranteed as compared to those vectors used previously. These vectors may produce a sufficient quantity of factor IX proteins to cause the phenotypic modification for hemophilia B patients.

Human thioredoxin reductase directly reduces lipid hydroperoxides by NADPH and selenocystine strongly stimulates the reaction via catalytically generated selenols

Human placenta thioredoxin reductase (HP-TR) in the presence of NADPH-catalyzed reduction of (15S)-hydroperoxy-(5Z),(8Z),11(Z),13(E)-eicosatetraenoic acid ((15S)-HPETE) into the corresponding alcohol ((15S)-HETE). Incubation of 50 nM HP-TR and 0.5 mM NADPH with 300 microM 15-HPETE for 5 min resulted in formation of 16.5 microM 15-HETE. After 60 min, 74.7 microM 15-HPETE was reduced. The rate of the reduction of 15-HPETE by the HP-TR/NADPH peroxidase system was increased 8-fold by the presence of 2.5 microM selenocystine, a diselenide amino acid. In this case, 15-HPETE was catalytically reduced by the selenol amino acid, selenocysteine, generated from the diselenide by the HP-TR/NADPH system. To a smaller extent, selenodiglutathione or human thioredoxin also potentiated the reduction of 15-HPETE by HP-TR. Hydrogen peroxide and 15-HPETE were reduced at approximately the same rate by HP-TR, thioredoxin, and selenocystine. In contrast, t-butyl hydroperoxide was reduced at a 10-fold lower rate. Our data suggest two novel pathways for the reduction and detoxification of lipid hydroperoxides, hydrogen peroxide, and organic hydroperoxides, i.e. the human thioredoxin reductase-dependent pathway and a coupled reduction in the presence of selenols or selenide resulting from the reduction of selenocystine or selenodiglutathione.

Characterization of bronchodilator effects and fate of S-nitrosothiols in the isolated perfused and ventilated guinea pig lung

In this study the effects of S-nitrosothiols, in particular S-nitrosoglutathione (GSNO), were evaluated with regard to their bronchodilating properties, both after infusion via the pulmonary circulation and after inhalation, in the isolated perfused and ventilated guinea pig lung. Infused GSNO induced bronchorelaxation of lungs that were precontracted with methacholine. During a 15-min period of single-passage perfusion with GSNO (10 microM), maximally 10% was taken up and/or degraded by the lung. A spontaneous breakdown of GSNO in the perfusion buffer was also observed, which was partially accompanied by the formation of nitrite. Low levels of nitric oxide (NO) were detected in the perfusion buffer when GSNO was present. This was due to the presence of contaminating transition metals, because EDTA and 2,2'-dipyridyl largely reduced the formation of NO. The NO-scavenging agents oxyhemoglobin and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide abolished levels of NO in the buffer but did not abolish GSNO-induced bronchodilation. The effects of infused GSNO are therefore attributed to an action of the intact S-nitrosothiol and not to NO released from GSNO in the perfusion buffer. Similarly, perfusion with S-nitrosated glutathione isopropyl ester, cysteinyl glycine, N-acetyl-L-cysteine or N-acetyl-D,L-penicillamine, but not with nitrosated bovine serum albumin or sodium nitrite, was found to induce bronchodilation. Inhalation of nebulized GSNO induced bronchodilation of methacholine-precontracted lungs with a rapid onset of action, although it was a less potent bronchodilator than salbutamol. The results show that infused or inhaled S-nitrosothiols have bronchodilating properties in the isolated perfused and ventilated guinea pig lung.