Molecular cytogenetic characterization of the genome organization of the 6-banded armadillo (Euphractus sexcinctus)

Xenarthra, as the probable earliest offshoot of the placental tree, represents a key taxon for understanding mammalian phylogeny. To gain further insight into the chromosomal evolution and genome organization of the xenarthrans, we have established the first genome-wide comparative chromosome map between human and the 6-banded armadillo (Euphractussexcinctus, 2n = 58), a basal species on the Xenarthra branch, by reciprocal cross-species chromosome painting. In total, 22 human autosomal paints revealed 41 homologous segments in the euchromatic genome of E. sexcinctus. Our results provide further support for the notion that the 2 human homologous segmental associations, i.e. HSA 2/8 and 7a/10p, could constitute the synapomorphies that unite the xenarthrans. Moreover, we propose that the putative ancestral Xenarthra karyotype closely resemble the 2n = 54 karyotype of the E. sexcinctus, consisting of the equivalents of HSA1p, 1q, 2a, 2b, 2c/8c, 3/21, 4a, 4b/8b, 5, 6a, 6b, 7a/10p, 7b/16p, 8a, 9, 10q, 11, 12a/22a, 12b/22b, 13, 14/15, 16q/19q, 17, 18, 19p, 20, and X. In addition, we have analysed the C-banding patterns of E. sexcinctus, and cloned, FISHmapped and sequenced 7 novel repetitive DNA segments, providing further information on the complexity of genome architecture of E. sexcinctus.

Comparative In Vivo Study on the Desensitizing Efficacy of Dentin Desensitizers and One-bottle Self-etching Adhesives

Dentin desensitizers and one-bottle self-etching adhesives can significantly reduce dentin hypersensitivity. Clinical desensitizing effectiveness depends on the individual dentin desensitizers/adhesives used.

Effect of Saliva Contamination and Decontamination on Bovine Enamel Bond Strength of Four Self-etching Adhesives

Salivary contamination before and after priming could significantly reduce the enamel bond strength of self-etching adhesives. Proper isolation should be performed before and during application of the adhesives and placement of the resin composite. Thorough water-spraying could significantly improve the μTBS of saliva-contaminated enamel.

Chromosome painting among Proboscidea, Hyracoidea and Sirenia: support for Paenungulata (Afrotheria, Mammalia) but not Tethytheria

Despite marked improvements in the interpretation of systematic relationships within Eutheria, particular nodes, including Paenungulata (Hyracoidea, Sirenia and Proboscidea), remain ambiguous. The combination of a rapid radiation, a deep divergence and an extensive morphological diversification has resulted in a limited phylogenetic signal confounding resolution within this clade both at the morphological and nucleotide levels. Cross-species chromosome painting was used to delineate regions of homology between Loxodonta africana (2n=56), Procavia capensis (2n=54), Trichechus manatus latirostris (2n=48) and an outgroup taxon, the aardvark (Orycteropus afer, 2n=20). Changes specific to each lineage were identified and although the presence of a minimum of 11 synapomorphies confirmed the monophyly of Paenungulata, no change characterizing intrapaenungulate relationships was evident. The reconstruction of an ancestral paenungulate karyotype and the estimation of rates of chromosomal evolution indicate a reduced rate of genomic repatterning following the paenungulate radiation. In comparison to data available for other mammalian taxa, the paenungulate rate of chromosomal evolution is slow to moderate. As a consequence, the absence of a chromosomal character uniting two paenungulates (at the level of resolution characterized in this study) may be due to a reduced rate of chromosomal change relative to the length of time separating successive divergence events.

Karyotype relationships of six bat species (Chiroptera, Vespertilionidae) from China revealed by chromosome painting and G-banding comparison

The Vespertilionidae is the largest family in the order Chiroptera and has a worldwide distribution in the temperate and tropical regions. In order to further clarify the karyotype relationships at the lower taxonomic level in Vespertilionidae, genome-wide comparative maps have been constructed between Myotis myotis (MMY, 2n = 44) and six vesper bats from China: Myotis altarium (MAL, 2n = 44), Hypsugo pulveratus (HPU, 2n = 44), Nyctalus velutinus (NVE, 2n = 36), Tylonycteris robustula (TRO, 2n = 32), Tylonycteris sp. (TSP, 2n = 30)and Miniopterus fuliginosus (MFU, 2n = 46) by cross-species chromosome painting with a set of painting probes derived from flow-sorted chromosomes of Myotis myotis. Each Myotis myotis autosomal probe detected a single homologous chromosomal segment in the genomes of these six vesper bats except for MMY chromosome 3/4 paint which hybridized onto two chromosomes in the genome of M. fuliginosus. Our results show that Robertsonian translocation is the main mode of karyotype evolution in Vespertilionidae and that the addition of heterochromatic material also plays an important role in the karyotypic evolution of the genera Tylonycteris and Nyctalus. Two conserved syntenic associations (MMY9 + 23 and 18 + 19) could be the synapomorphic features for the genus Tylonycteris. The integration of our maps with the published maps has enabled us to deduce chromosomal homologies between human and these six vesper bats and provided new insight into the karyotype evolution of the family Vespertilionidae.

Essential role of Ca2+ release channels in angiotensin II-induced Ca2+ oscillations and mesangial cell contraction

The increased resistance of the glomerulus as a result of contractile dysfunction of mesangial cells (MCs) is associated with reduction of glomerular filtration rate and development of glomerulosclerosis. Evidences show MCs contraction changes with intracellular Ca(2+) concentration ([Ca(2+)](i)). Here, we explore the mechanism of angiotensin II (AngII)-induced Ca(2+) oscillations and MCs contraction. Primary MCs from 3-month-old and 28-month-old rats were used for detection of Ca(2+) oscillations and MC planar area with confocal microscopy. AngII could induce typical Ca(2+) oscillations and contraction of MCs. This process was abolished by thapsigargin, 2-aminoethoxydiphenyl borate, or 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphorylcholine, and partially inhibited by ryanodine, but could not be inhibited in the absence of extracellular Ca(2+). Ryanodine receptors (RyRs) and inositol 1,4,5-trisphosphate (InsP(3)) receptors displayed a strong colocalization, which may contribute to the amplification of Ca(2+) response. MLC(20) phosphorylation and MC planar area were associated with AngII-induced Ca(2+) oscillations. The frequency of Ca(2+) oscillations was dependent on the AngII concentration and correlated with the MCs' contractive extent, which could be attenuated by KN-93. The amplitude reduction of oscillations correlated with the decrease in aging-related contraction. In conclusion, [Ca(2+)](i) response of MCs to AngII is characterized by repetitive spikes through the following repetitive cycles: Ca(2+) release by phospholipase C -InsP(3) pathway, Ca(2+) amplification by Ca(2+)-activated RyRs and Ca(2+) reuptake by the endoplasmic reticulum. MCs contraction can be modulated by oscillations not only in an AngII-induced frequency-dependent mode but also in an aging-related, amplitude-dependent mode.

A prospective study comparing conventional methods against a structured method of gaining patients’ informed consent for tonsillectomy

OBJECTIVE

By providing junior members of medical staff with appropriate guidelines one can achieve an improved standard of informed consent for tonsillectomy, than is provided at present.

DESIGN

A prospective study of 138 consecutive patients.

SETTING

District General Hospital.

PARTICIPANTS

A total of 138 patients undergoing routine tonsillectomy split into two groups. Group A (n=87), the conventional group, gave consent in our unit's standard manner to various grades of doctors by using a hospital general surgical consent form. Most gave their consent as outpatients, while some consented on admission. Group B (n=51), the structured consent group, gave their consent in pre-admission clinic, to an SHO using a standardized tonsillectomy consent form and a structured interview technique.

MAIN OUTCOME MEASURES

A preoperative questionnaire regarding the knowledge of tonsillectomy.

RESULTS

Improvement of the awareness of the risks involved with tonsillectomy was achieved by the structured consent Group B; 82% of Group A were aware of postoperative pain compared with 94% of group B (P=0.04); 63% of group A were aware of infection compared with 82% of group B (P=0.02); 100% of group B had read the consent form before signing compared with 80% of group A (P<0.01). There was no statistical difference in the awareness of postoperative haemorrhage (91 versus 98%, P=0.15).

CONCLUSION

By providing junior medical staff with guidelines, senior staff retain responsibility for consent while improving the standard of informed consent for tonsillectomy.

Interfacial interaction of tartaric acid with hydroxyapatite and enamel

The purpose of this study was to investigate the interfacial interaction of tartaric acid with hydroxyapatite and enamel. Hydroxyapatite particles were mixed with 15% (w/v) alcohol-aqueous (1:1) solution of tartaric acid for 72 h. After the mixture, the filtrate was separated from the solid. The filtrate, the solid, hydroxyapatite, and tartaric acid were dried for FTIR and XRD analysis. Enamel disks etched with tartaric acid for 60 s were analyzed by attenuated total reflectance (ATR). Enamel disks etched with 15% tartaric acid for 15, 30, 60, 120 s were analyzed by SEM. FTIR spectra showed carboxylate in the solid and in subtraction spectra. ATR spectra revealed carboxylate on the enamel surfaces. XRD data indicated the formation of calcium tartrate and calcium hydrogen phosphate after the reaction of tartaric acid with hydroxyapatite. SEM observations revealed typical decalcification of the periphery of the enamel rods due tartaric acid etching. It is concluded that tartaric acid can decalcify and chemisorb onto HA simultaneously, hence, tartaric acid could be used as etchant and ingredient of self-etching primers in adhesive dentistry.

Karyotypic conservatism in the suborder Feliformia (Order Carnivora)

Multidirectional comparative chromosome painting was used to investigate the karyotypic relationships among representative species from three Feliformia families of the order Carnivora (Viverridae, Hyaenidae and Felidae). Complete sets of painting probes derived from flow-sorted chromosomes of the domestic dog, American mink, and human were hybridized onto metaphases of the spotted hyena (Crocuta crocuta, 2n = 40) and masked palm civet (Paguma larvata, 2n = 44). Extensive chromosomal conservation is evident in these two species when compared with the cat karyotype, and only a few events of chromosome fusion, fission and inversion differentiate the karyotypes of these Feliformia species. The comparative chromosome painting data have enabled the integration of the hyena and palm civet chromosomes into the previously established comparative map among the domestic cat, domestic dog, American mink and human and improved our understanding on the karyotype phylogeny of Feliformia species.

New insights into the karyotypic relationships of Chinese muntjac (Muntiacus reevesi), forest musk deer (Moschus berezovskii) and gayal (Bos frontalis)

To investigate the karyotypic relationships between Chinese muntjac (Muntiacus reevesi), forest musk deer (Moschus berezovskii) and gayal (Bos frontalis), a complete set of Chinese muntjac chromosome-specific painting probes has been assigned to G-banded chromosomes of these three species. Sixteen autosomal probes (i.e. 6-10, 12-22) of the Chinese muntjac each delineated one pair of conserved segments in the forest musk deer and gayal, respectively. The remaining six autosomal probes (1-5, and 11) each delineated two to five pairs of conserved segments. In total, the 22 autosomal painting probes of Chinese muntjac delineated 33 and 34 conserved chromosomal segments in the genomes of forest musk deer and gayal, respectively. The combined analysis of comparative chromosome painting and G-band comparison reveals that most interspecific homologous segments show a high degree of conservation in G-banding patterns. Eleven chromosome fissions and five chromosome fusions differentiate the karyotypes of Chinese muntjac and forest musk deer; twelve chromosome fissions and six fusions are required to convert the Chinese muntjac karyotype to that of gayal; one chromosome fission and one fusion separate the forest musk deer and gayal. The musk deer has retained a highly conserved karyotype that closely resembles the proposed ancestral pecoran karyotype but shares none of the rearrangements characteristic for the Cervidae and Bovidae. Our results substantiate that chromosomes 1-5 and 11 of Chinese muntjac originated through exclusive centromere-to-telomere fusions of ancestral acrocentric chromosomes.

Cross-species chromosome painting in the golden mole and elephant-shrew: support for the mammalian clades Afrotheria and Afroinsectiphillia but not Afroinsectivora

Cross-species painting (fluorescence in situ hybridization) with 23 (human Homo sapiens (HSA)) chromosome-specific painting probes (HSA 1-22 and the X) was used to delimit regions of homology on the chromosomes of the golden mole (Chrysochloris asiaticus) and elephant-shrew (Elephantulus rupestris). A cladistic interpretation of our data provides evidence of two unique associations, HSA 1/19p and 5/21/3, that support Afrotheria. The recognition of HSA 5/3/21 expands on the 3/21 synteny originally designated as an ancestral state for all eutherians. We have identified one adjacent segment combination (HSA2/8p/4) that is supportive of Afroinsectiphillia (aardvark, golden mole, elephant-shrew). Two segmental combinations (HSA 10q/17 and HSA 3/20) unite the aardvark and elephant-shrews as sister taxa. The finding that segmental syntenies in evolutionarily distant taxa can improve phylogenetic resolution suggests that they may be useful for testing sequence-based phylogenies of the early eutherian mammals. They may even suggest clades that sequence trees are not recovering with any consistency and thus encourage the search for additional rare genomic changes among afrotheres.

Karyotypic relationships of horses and zebras: results of cross-species chromosome painting

Complete sets of chromosome-specific painting probes, derived from flow-sorted chromosomes of human (HSA), Equus caballus (ECA) and Equus burchelli (EBU) were used to delineate conserved chromosomal segments between human and Equus burchelli, and among four equid species, E. przewalskii (EPR), E. caballus, E. burchelli and E. zebra hartmannae (EZH) by cross-species chromosome painting. Genome-wide comparative maps between these species have been established. Twenty-two human autosomal probes revealed 48 conserved segments in E. burchelli. The adjacent segment combinations HSA3/21, 7/16p, 16q/19q, 14/15, 12/22 and 4/8, presumed ancestral syntenies for all eutherian mammals, were also found conserved in E. burchelli. The comparative maps of equids allow for the unequivocal characterization of chromosomal rearrangements that differentiate the karyotypes of these equid species. The karyotypes of E. przewalskii and E. caballus differ by one Robertsonian translocation (ECA5 = EPR23 + EPR24); numerous Robertsonian translocations and tandem fusions and several inversions account for the karyotypic differences between the horses and zebras. Our results shed new light on the karyotypic evolution of Equidae.

Reciprocal chromosome painting among human, aardvark, and elephant (superorder Afrotheria) reveals the likely eutherian ancestral karyotype

The Afrotheria, a supraordinal grouping of mammals whose radiation is rooted in Africa, is strongly supported by DNA sequence data but not by their disparate anatomical features. We have used flow-sorted human, aardvark, and African elephant chromosome painting probes and applied reciprocal painting schemes to representatives of two of the Afrotherian orders, the Tubulidentata (aardvark) and Proboscidea (elephants), in an attempt to shed additional light on the evolutionary affinities of this enigmatic group of mammals. Although we have not yet found any unique cytogenetic signatures that support the monophyly of the Afrotheria, embedded within the aardvark genome we find the strongest evidence yet of a mammalian ancestral karyotype comprising 2n = 44. This karyotype includes nine chromosomes that show complete conserved synteny to those of man, six that show conservation as single chromosome arms or blocks in the human karyotype but that occur on two different chromosomes in the ancestor, and seven neighbor-joining combinations (i.e., the synteny is maintained in the majority of species of the orders studied so far, but which corresponds to two chromosomes in humans). The comparative chromosome maps presented between human and these Afrotherian species provide further insight into mammalian genome organization and comparative genomic data for the Afrotheria, one of the four major evolutionary clades postulated for the Eutheria.

Comparative molecular cytogenetic studies in the order Carnivora: mapping chromosomal rearrangements onto the phylogenetic tree

We have made a set of chromosome-specific painting probes for the American mink by degenerate oligonucleotide primed-PCR (DOP-PCR) amplification of flow-sorted chromosomes. The painting probes were used to delimit homologous chromosomal segments among human, red fox, dog, cat and eight species of the family Mustelidae, including the European mink, steppe and forest polecats, least weasel, mountain weasel, Japanese sable, striped polecat, and badger. Based on the results of chromosome painting and G-banding, comparative maps between these species have been established. The integrated map demonstrates a high level of karyotype conservation among mustelid species. Comparative analysis of the conserved chromosomal segments among mustelids and outgroup species revealed 18 putative ancestral autosomal segments that probably represent the ancestral chromosomes, or chromosome arms, in the karyotype of the most recent ancestor of the family Mustelidae. The proposed 2n = 38 ancestral Mustelidae karyotype appears to have been retained in some modern mustelids, e.g., Martes, Lutra, Ictonyx, and Vormela. The derivation of the mustelid karyotypes from the putative ancestral state resulted from centric fusions, fissions, the addition of heterochromatic arms, and occasional pericentric inversions. Our results confirm many of the evolutionary conclusions suggested by other data and strengthen the topology of the carnivore phylogenetic tree through the inclusion of genome-wide chromosome rearrangements.

Effect of air abrasion and resin composite on microleakage of Class V restorations bonded with self-etching primers

PURPOSE

The purpose of this in vitro study was to determine the effect of air-abrasion pretreatment on microleakage of Class V resin composite restorations bonded with self-etching primers.

MATERIALS AND METHODS

A total of 54 Class V cavities prepared either with diamond burs or air abrasion (KCP 1000) was restored with resin composites using adhesive systems with self-etching priming agents (Clearfil Liner Bond 2 or Resulcin AquaPrime + Monobond) and thermocycled 2,500 times. The degree of dye penetration (0.5% methylene blue solution) was scored on an ordinal scale at 25X magnification on longitudinally cut sections of the specimens. Wall adaptation at the tooth-restoration interfaces was evaluated under a SEM using replicas of the sectioned teeth.

RESULTS

Severe microleakage occurred at the gingival dentinal margins, and less microleakage was detected at the enamel cavity margins. Nonparametrical statistical analysis (H-test) demonstrated no significant differences in microleakage among the different groups. Comparison of dye penetration data and SEM findings showed that with both self-etching priming agents, microleakage occurred in the absence of gaps.

CONCLUSION

Use of air abrasion in combination with self-etching priming agents cannot prevent microleakage at the dentin-resin interface of Class V resin composite restorations.

A bis-sesquiterpene and sesquiterpenolides from Inula macrophylla

Macrophyllidimer C, a novel bis-sesquiterpene, in which the two sesquiterpene units are directly connected by a C-C bond, and eight other sesquiterpenolides were obtained from the bark of Inula macrophylla. Seven of these, macrophyllilactones A-G, are new eudesmanolide- and elemanolide-type sesquiterpenes. Their structures were determined on the basis of spectroscopic evidence and chemical reaction.

[Dynamic change and expression of matrix metalloproteinase-2, -9 in alcoholic liver disease in rats]

OBJECTIVE

To evaluate the dynamic change and expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in alcoholic liver disease in rats.

METHODS

Alcoholic liver disease rat model was established by gavage. The expression of MMP-2 and MMP-9 was studied by immunohistochemistry, and the result was analyzed by picture quantitative analysis technique.

RESULTS

The expression of MMP-2 and MMP-9 was significantly higher in rats of model group than that of control group (P<0.05). The level of MMP-2 and MMP-9 increased gradually with the progress of alcoholic liver disease. Immunoreactive MMP-2 was expressed in endothelial cells of hepatic artery and portal vein, sinusoidal endothelial cells and sinusoidal cells. Immunoreactive MMP-9 was observed in sinusoidal cells and hepatic cells around the vein.

CONCLUSIONS

MMP-2 and MMP-9 increa with the progress of alcoholic liver disease. They might be involved in the development of alcoholic liver disease.

The food-process subsystem for CELSS: a conceptual analysis

A controlled ecological life support system (CELSS) is required to sustain life for future long-duration space missions. Food processing is an important subsystem component of a CELSS. Factors for designing the food-process subsystem are identified and characterized in this analysis. Interactions of the subsystem with other subsystems in a CELSS are also discussed.

[Quality of aquatic environment at Haihe River and the pollutant fluxes flowing into sea]

On the basis of the data of water quality monitored from 1993 to 1997, the pollution indexes of each pollutant was computed. The results showed that the pollution at Haihe river was severe. The rank of water quality at all monitoring site were between IV and V grade. The main pollution factors were NH3-N, NO2-N and organic contaminants. During the 5 years, water quality of Haihe River was improved, however, the pollutant fluxes flowing into Bohai Bay, especially CODMn, BOD, NH3-N, NO3-N and NO2-N, were increased, they were increased from 1555, 655, 337, 156 and 25 t.a-1 in 1993 to 8710, 4317, 2516, 1528 and 188 t.a-1 in 1996, and sharply decreased to 1331, 973, 572, 355 and 31 t.a-1 in 1997, respectively. It may be mainly due to the change of runoff at Haihe River.

[Effects of sense and antisense tissue inhibitor metalloproteinase-1 on apoptosis of rat glomerular mesangial cells and its related-gene expressions]

OBJECTIVE

To investigate the role of tissue inhibitor of metalloproteinase-1 (TIMP-1) in apoptosis of rat glomerular mesangial cells (RMC) in vitro.

METHODS

TIMP-1 full length cDNA cloned in previous work was used to construct two recombinant plasmids, eukaryotic expression rector, pcDNA3-TIMP-1 (PTs) encoding sense TIMP-1 and pcDNA3-ATIMP-1 (PTas) encoding antisense TIMP-1. These two vectors were then transfected into RMC with lipofectin DOTAP. Northern blotting was used to detect the expression of sense and antisense TIMP-1. Apoptosis was induced in normal RMC, RMC transfected with pCDNA3, PTs and PTas by serum deprivation. Those cells were monitored for apoptosis over extended periods of time (12 h approximately 4 d) by TUNEL and DNA electrophoressis. Furthermore, the expression of apoptosis related-genes was also investigated by RT-PCR.

RESULTS

Northern blot analysis and RT-PCR demonstrated that cells transfected with exogenous genes effectively expressed sense or antisense TIMP-1 mRNA. RMC transfected with PTas underwent apoptosis after 12 h of serum deprivation, normal RMC and RMC transfected with pcDNA3 underwent apoptosis after 48 hours in serum-free medium, while RMC transfected with PTs did not undergo apoptosis until 4 days after serum deprivation. Furthermore, TIMP-1 upregulation inhibited expression of bax but had no effect on the expression of bcl-2.

CONCLUSION

TIMP-1 suppressed apoptosis of RMC, which suggests a novel activity of TIMP-1 in kidney. Antisense TIMP-1 promotes apoptosis in RMC. The effects of TIMP-1 on RMC apoptosis perhaps correlate with inhibition of bax expression.

[STAT mediated thrombin induction of tissue inhibitor of metalloproteinase1 in human mesangial cells]

OBJECTIVE

To depict the role of signal transducers and activators of transcription (STAT) pathway in thrombin induction of tissue inhibitor of matrix metalloproteinase-1 (TIMP1) in human mesangial cells.

METHODS

Human mesangial cells were isolated, seeded in RPMI1640, and stimulated with thrombin (0.5, 1.5, and 4.5 U/ml). Northern blot and electrophoretic mobility shift assay (EMSA) were employed to determine the levels of TIMP1 mRNA and STAT-DNA binding activity in the cells, respectively. In order to confirm the role of STAT in this cell event, STAT 1 and STAT 3 antisense oligonucleotides were employed to suppress their intra-cellular activity.

RESULTS

CONCLUSION

Cultured human mesangial cells expressed basal TIMP1 mRNA, and thrombin promoted TIMP1 gene transcription in dose-dependent manner. Hirudin, a specific inhibitor of thrombin, blocked thrombin-induced TIMP1 gene expression. Thrombin promoted STAT DNA binding activity in a manner parallel to TIMP1 mRNA expression, which was inhibited by its inhibitor, hirudin again. STAT1 and STAT3 antisense oligonucleotides inhibited both STAT DNA binding activity and TIMP1 mRNA expression in mesangial cells.

CONCLUSION

STAT mediates the thrombin-induced expression of TIMP1 gene in cultured human mesangial cells.

New bisabolane sesquiterpenes from Ligularia songarica

Phytochemical investigation of Ligularia songarica (Compositae) afforded seven new bisabolane-type sesquiterpenes. Their structures were confirmed on the basis of spectroscopic methods, especially 2D-NMR techniques, and compound 7 showed stronger antibacterial activity against Escherichia coli, Pseudomonas acruginosa and Salmonella pullorum.

The gain-of-function G389R variant of the beta1-adrenoceptor does not influence blood pressure or heart rate response to beta-blockade in hypertensive subjects

Mutation scanning of the beta1-adrenoceptor gene has identified a polymorphism, G389R, that markedly affects G-protein coupling of the receptor and resulting cAMP production. We have investigated the effect of this functionally active polymorphism on clinical response to beta-adrenoceptor blockade. Two cohorts of untreated hypertensive patients randomly assigned to a beta1-selective beta-blocker at the start of antihypertensive therapy were studied retrospectively to see if the G389R polymorphism influenced the response in terms of blood pressure and heart rate. The blood pressure and heart rate responses to treatment were assessed 4 weeks later and compared with the G389R genotype, ascertained by PCR/restriction fragment length polymorphism. The falls in blood pressure and heart rate for the first group (n = 92) by genotype were: GG, 20.1 +/- 3.5/13.9 +/- 2.7 mmHg (systolic/diastolic blood pressure), 18.4 +/- 2.2 beats/min; GR, 20.0 +/- 2.2/15.0 +/- 1.3 mmHg, 16.5 +/- 1.5 beats/min; RR, 20.8 +/- 2.3/13.4 +/- 1.1 mmHg, 16.0 +/- 1.4 beats/min. For the second group (n = 55) the corresponding falls were: GG, 17.0 +/- 4.3/11.2 +/- 3.4 mmHg, 12.0 +/- 3.5 beats/min; GR, 16.6 +/- 1.8/14.4 +/- 1.1 mmHg, 13.1 +/- 2.1 beats/min; RR, 18.0 +/- 1.6/13.0 +/- 1.4 mmHg, 14.4 +/- 1.4 beats/min. The G389R genotype also failed to have a significant effect on pretreatment blood pressure or heart rate in either group. These data suggest that, despite clear functional differences between the G389R receptor variants expressed in vitro, the polymorphism does not affect the haemodynamic response of hypertensive subjects to chronic beta1-adrenoceptor blockade.

[Spatial variability of soil nutrients based on geostatistics combined with GIS--a case study in Zunghua City of Hebei Province]

Geostatistics combined with GIS was applied to analyze the spatial variability of soil nutrients in topsoil (0-20 cm) in Zunghua City of Hebei Province. GIS can integrate attribute data with geographical data of system variables, which makes the application of geostatistics technique for large spatial scale more convenient. Soil nutrient data in this study included available N (alkaline hydrolyzing nitrogen), total N, available K, available P and organic matter. The results showed that the semivariograms of soil nutrients were best described by spherical model, except for that of available K, which was best fitted by complex structure of exponential model and linear with sill model. The spatial variability of available K was mainly produced by structural factor, while that of available N, total N, available P and organic matter was primarily caused by random factor. However, their spatial heterogeneity degree was different: the degree of total N and organic matter was higher, and that of available P and available N was lower. The results also indicated that the spatial correlation of the five tested soil nutrients at this large scale was moderately dependent. The ranges of available N and available P were almost same, which were 5 km and 5.5 km, respectively. The range of total N was up to 18 km, and that of organic matter was 8.5 km. For available K, the spatial variability scale primarily expressed exponential model between 0-3.5 km, but linear with sill model between 3.5-25.5 km. In addition, five soil nutrients exhibited different isotropic ranges. Available N and available P were isotropic through the whole research range (0-28 km). The isotropic range of available K was 0-8 km, and that of total N and organic matter was 0-10 km.

Thrombin stimulates MMP-9 mRNA expression through AP-1 pathway in human mesangial cells

AIM

To investigate the thrombin mediated induction of gelatinase B (MMP-9) in mesangial cells (MC) and the underlying role of activator protein-1 (AP-1).

METHODS

Cultured human mesangial cells were exposed to thrombin in the presence or absence of hirudin, curcumin, and c-fos antisense or sense oligonucleotides. Northern hybridization was employed to assess MMP-9 mRNA expression, and electrophoretic mobility shift assay (EMSA) for AP-1 DNA binding activity.

RESULTS

The levels of MMP-9 mRNA in the cell treated with different doses of thrombin (500, 1500, and 4500 u/L, respectively) were 1.1, 3.3, and 4.8 times higher than that in the control, respectively. There was also an increase in AP-1 binding activity (3.5, 5.9, and 7.1 fold than that of the control) in accordance with MMP-9 mRNA levels in the presence of thrombin. Hirudin, curcumin, and c-fos antisense oligonucleotides could block thrombin-induced expression of MMP-9 mRNA as well as AP-1 binding activity.

CONCLUSION

Thrombin is a potent stimulator of MMP-9 gene expression in human mesangial cells, and the underlying intracellular events are mediated, at least partly, by AP-1 pathway.

Effects of air abrasion and acid etching on the microleakage of preventive Class I resin restorations: an in vitro study

PURPOSE

To evaluate the effects of air abrasion, acid etching, and the combination of both procedures on the microleakage of preventive Class I resin restorations.

MATERIALS AND METHODS

Eighty-four extracted human molar teeth were randomly assigned to seven groups with 12 teeth each. Occlusal fissures were opened with a diamond bur and etched with phosphoric acid (groups I and VI); prepared with a diamond bur without etching (group VII); air abraded with the KCP 1000, using 50-micron aluminum oxide particles without etching (group II), and with phosphoric acid etching (group III); or air abraded with 27-micron aluminum oxide particles without etching (group IV), and with phosphoric acid etching (group V). Preparations were filled with a low-viscosity resin composite (Liquicoat, groups I to V) or with a low-viscosity polyacid-modified resin composite (PrimaFlow, groups VI and VII). Six teeth in each group were thermocycled (5 degrees-55 degrees C, 2500 cycles). Dye penetration (methylene blue) was evaluated in ordinal scale.

RESULTS

The number of non-thermocycled and thermocycled specimens revealing no microleakage was as follows: group I, 6 and 1; group II, 2 and 2; group III, 4 and 3; group IV, 0 and 0; group V, 1 and 0; group VI, 3 and 2; and group VII, 0 and 0, respectively. No significant differences existed between the thermocycled specimens and non-thermocycled specimens, except within group I.

CLINICAL SIGNIFICANCE

Results indicated that (1) air-abrasion treatment with 27-micron particles is less effective in preventing microleakage compared to 50-micron particles, (2) air abrasion should be combined with acid etching to reduce microleakage of preventive Class I resin restorations, and (3) acid etching significantly reduces microleakage of the low-viscosity polyacid-modified resin composite in preventive Class I restorations.

[AP-1 mediated signal transduction in thrombin-induced regulation of PAL-1 expression in human mesangial cells]

OBJECTIVE

To evaluate activator protein-1 (AP-1) mediated mechanisms in thrombin-induced qlasminogen activator inhibitor-1 (PAI-1) expression in cultured human glomerular mesangial cells (MCs).

METHODS

Electrophoretic mobility shift assay (EMSA) was employed to assess AP-1 DNA-binding activity, and Western blot hybridization was used for quantification of c-fos and c-jun, two subunits of AP-1 dimers. PAI-1 activity and mRNA expression were analysed by the fibrin plate assay and Northern hybridization, respectively.

RESULTS

Thrombin concentration enhanced PAI-1 activity in the supernatant and stimulated PAI-1 mRNA expression in cultured MCs. PAI-1 activity was blocked by hirudin, a specific inhibitor of thrombin. Further study demonstrated that thrombin promoted AP-1 DNA-binding activity but exerted little effect on c-fos or c-jun. Curcumin (AP-1 inhibitor), staurosporine (PKC inhibitor), and genistein (PTK inhibitor) all reduced AP-1-mediated PAI-1 mRNA expression induced by thrombin in cultured MCs.

CONCLUSION

The present study indicates that in cultured human MCs, thrombin stimulates PAI-1 expression through an AP-1 signal pathway, which may be mediated by PKC and PTK.

Identification of monozygotic twins that are concordant for preeclampsia

Preeclampsia is thought to be discordant in monozygotic twins. While recruiting for a genetic study into preeclampsia, we identified 4 sets of twins and a triplet gestation; all were monozygous on deoxyribonucleic acid "fingerprinting." Two twins were concordant for preeclampsia, and 2 of the triplets had pregnancy-induced hypertension, although only 1 of them had proteinuria. Hence we confirm the existence of monozygotic twins that are concordant for preeclampsia.