[Amplifying variable region gene of light chain of monoclonal antibody against human retinoblastoma by PCR]

OBJECTIVE

To acquire the variable region gene of light chain of monoclonal antibody against human retinoblastoma.

METHODS

Total RNA were extracted from hybridoma cells secreting specific monoclonal antibody(McAb) against human retinoblastoma(RB), then transcripted reversely into cDNA with random primers. The variable region of the light chain(VL) gene fragments were ampliflied using polymerase chain reaction(PCR) method. Agrose gel electrophoresis was confirmed.

RESULTS

1.5% agrose gel electrophoresis indicated that VL gene was about 340 base pairs.

CONCLUSION

The light chain variable region gene of the McAb against human RB was amplified successfully, which lays a good basis for construction of a recombinant antibody.

Mammalian plasma membrane ecto-nucleoside triphosphate diphosphohydrolase 1, CD39, is not active intracellularly. The N-glycosylation state of CD39 correlates with surface activity and localization

CD39 is a member of the membrane-bound ecto-nucleoside triphosphate diphosphohydrolase family. The active site for native CD39 is located on the outer surface of the cellular plasma membrane; however, it is not yet known at what stage this enzyme becomes active along the secretory pathway to the plasma membrane. In this study, sucrose density fractionations performed on CD39-transfected COS-7 cell membranes suggest that CD39 activity resides primarily in the plasma membrane. Furthermore, we have created recombinant, soluble versions of CD39, one that is secreted and others that are retained in the endoplasmic reticulum, to demonstrate that CD39 is not active until it reaches the plasma membrane both in yeast and COS-7 cells. Moreover, the secreted active soluble CD39 in COS-7 cells is found to receive a higher degree of N-glycan addition than the inactive form retained intracellularly. When COS-7 cells were treated with tunicamycin to prevent N-glycosylation, soluble CD39 was not detected in the extracellular medium and remained inactive intracellularly. Surface biotinylation analysis also revealed that surface-expressed wild type CD39 receives a higher degree of N-glycosylation than intracellular forms and that inhibition of N-glycosylation prevents its plasma membrane localization. In addition, both intact and digitonin-permeablized COS-7 cells transfected with CD39 possess similar ecto-ATPase activities, further supporting the conclusion that only surface-expressed CD39 is enzymatically active. All of these data suggest that intracellular CD39 is inactive and that only a fully glycosylated CD39 has apyrase activity and is localized at the cell surface.

PCR detection of Capnocytophaga species in dental plaque samples from children aged 2 to 12 years

The purpose of this study was to detect the presence of Capnocytophaga sputigena, C. ochracea, and C. gingivalis in plaque samples from the toothbrushes of 122 children, using a polymerase chain reaction (PCR) method. The subjects were 25, 85, and 12 children with healthy gingiva, gingivitis, and periodontitis, respectively, ranging in age from 2-12 years old. Plaque samples were collected from all erupted tooth sites using a sterile toothbrush. The mean amount of DNA recovered from the samples was approximately 19.3 microg, which was deemed sufficient for performing a PCR-based survey. C. sputigena prevalence in healthy, gingivitis, and periodontitis subjects was 48.0%, 36.5% and 25.0%, respectively, that for C. ochracea was 100%, 89.4%, and 50.0%, respectively, and that for C. gingivalis was 96.0%, 84.7%, and 75.0%, respectively. The lowest age of positive subjects was approximately 2 years. Our results showed that C. sputigena was moderately prevalent, whereas C. ochracea and C. gingivalis were commonly detected in the oral cavities of the tested children, suggesting that all of these species become established in the early years.

[Effect of thrombopoietin II on exsanguine thrombocytopenia mouse death rate]

OBJECTIVE

To study the effect of thrombopoietin II (TPO II) on the exsanguine thrombocytopenia mouse death rate.

METHODS

After the normal peripheral platelet counts were done on the samples obtained from the tail vein of purebred Babl/c mice before experiment, the purified ligand I of TPO II, artificial compound ligand II of TPO II and rhTPO were injected intraperitoneally once a day for 7 days. On d 7 and d 14, platelet counts were performed on 0.5 ml samples obtained from the supra-orbital vein, with the condition of the mouse death monitored daily.

RESULTS

On d 7, ligand I of TPO II group platelet counts were higher than that of the negative control group (P < 0.05), while not being significantly different from that of rhTPO group (P > 0.05). On d 14, the platelet counts of two TPO II groups increased significantly as compared with the negative control group (P < 0.01), showing no significant difference from that of rhTPO group (P > 0.05). Moreover, the platelet counts of mice in two TPO II groups and the positive group had shown an increasing tendency in the days following experiment. In addition, mouse death occurred in all groups of mice following their phlebotomy from the supraorbital vein on d 7. But the death rate of negative control group was evidently higher than that of any other groups (P < 0.05).

CONCLUSION

TPO II's biological activity obviously increases platelet production, thereby reducing the exsanguine thrombopenia mouse death rate.

[Study on anti-inflammatory, analgesic and antipyretic effects of bagmaking tea of sanyaku]

OBJECTIVE

To observe anti-inflammatory, analgesic and antipyretic effects of the Bagmaking Tea of Sanyaku in rats.

METHODS

mouse torsion modle induced by glacial acetic acid, mouse auricle swelling model induced by xylene and rat fever model induced by baker yeast were used.

RESULTS

Bagmaking Tea of Sanyaku could inhibit mouse torsion action, mouse auricle swelling and rat fever.

CONCLUSION

Bagmaking Tea of Sanyaku possessed anti-inflammatory, analgesic and antipyretic effects.

Assessing a role for enhancer-blocking activity in gene regulation within the murine T-cell receptor alpha/delta locus

Although situated close together within the T-cell receptor (TCR) alpha/delta locus, TCR delta and TCR alpha gene segments are controlled by two developmental stage-specific enhancers and are activated according to distinct developmental programmes. We previously used a stable transfection colony assay to identify an enhancer-blocking element, blocking element alpha/delta-1 (BEAD-1), between the TCR delta and alpha gene segments of the human TCR alpha/delta locus. We hypothesized that enhancer-blocking by BEAD-1 might be required to prevent the TCR delta enhancer from activating TCR alpha gene segment transcription and rearrangement at the double negative stage of thymocyte development. Here, we used a transfection approach to define partial enhancer-blocking activity in an analogous position of the murine TCR alpha/delta locus. To test the functional significance of this activity in vivo, we used gene targeting to delete the region from the endogenous locus. We found no perturbation of TCR delta and TCR alpha gene expression and rearrangement on targeted alleles, indicating that enhancer-blocking activity in this region is not required to maintain the developmentally distinct activation profiles of the two genes. We suggest that appropriate regulation may be achieved as a result of intrinsic biases in enhancer-promoter interactions or a developmental stage specificity to promoter function that is distinct from any additional specificity imposed by the enhancers themselves.

[Phenotyping and genotyping studies in a family with the compound heterozygosity for a deletional delta beta-thalassemia and a beta-thalassemia]

OBJECTIVE

To investigate the relationship between genotype and phenotype of a deletional delta beta-thalassemia and explore an approach to rapid prenatal diagnosis for compound heterozygotes of this defect and a beta-thalassemia.

METHODS

A total of ten members in a Chinese family who had a 5-year-old propositus with thalassemia major and requested prenatal diagnosis for the second pregnancy were investigated. For genotyping analysis, the deletional delta beta-thalassemia was characterized by gap-PCR method and beta-thalassemia mutations were defined by reverse dot blot(RDB). For phenotyping analysis, hematological data including the RBC indices, quantification of HbF and HbA2 by Hb electrophoresis and the ratio of globin chain Ggamma/(Ggamma+Agamma) analyzed by capillary electrophoresis (CE) were obtained.

RESULTS

The propositus inherited her mother's delta beta-thalassemia gene mutation and her father's CD41-42(-CTTT) frameshift mutation. Of nine members in this family screened for this type of deletion, four were positive and the phenotype could be explained satisfactorily by genotype. The results of prenatal diagnosis showed that the fetus was normal and had no beta-globin gene defects in both chromosomes.

CONCLUSION

This is the first time to have performed prenatal diagnosis in Chinese family at-risk of compound heterozygotes for beta-thalassemia and delta beta-thalassemia in mailand China. The strategy to analyze the disease presented here may be a valuable reference to the similar problem.

[The study on subclinical Epstein-Barr virus infection of heroin addicts]

OBJECTIVE

To study the subclinical EBV infection and related factors among heroin addicts.

METHODS

Three hundred and twelve heroin addicts were tested for serum EBV-VCA-IgA antibody by immunoenzyme technique population, four hundred and twenty one serum specimens from general were selected as control.

RESULTS

Ninty nine heroin addicts (31.51%) were found to be EBV positive. Three people from control group (0.7%) were found to be EBV positive. EBV prevalence rates were significantly different among heroin addict groups according to a group (P = 0.05), duration of addiction. However the dose and sex difference of heroin addicts was not associated with EBV infection rate.

CONCLUSION

The high infection rate of EBV in heroin addicts might be connected with different kinds of factors, hence worthy of supervising the subclinical EBV infection of heroin addicts.

[Fluorescence enhancement and laser behavior of Rhodamine 6G in micell]

Fluorescence of Rhodamine 6G in aqueous solution is effectively enhanced by using anionic sodium dodecylsulfate (SDS) surfactant. When the concentration of Rhodamine 6G is 5.47 x 10(-7) mol.L-1 and 5.47 x 10(-4) mol.L-1, maximal enhancement ratio can be 1.95 and 9.7, respectively. In the latter case, using SDS can reduce the threshold and improve the energy conversion efficiency of the dye laser of Rhodamine 6G. In the absence of SDS, the laser threshold power density is near 65 MW.cm-2. While in the present of SDS, the threshold is reduced to 0.8 MW.cm-2. The laser energy conversion efficiency can reach 25% when the pumping power density is 65 MW.cm-2. We also observed the red shifts of absorption spectrum, fluorescence spectrum and the dye laser spectrum in the present of SDS. The physical mechanism of the phenomena is discussed.

[The roles of vascular endothellial growth factor and endothelin-1 on pulmonary vascular remodelling in rats with hypoxia-induced pulmonary hypertension]

OBJECTIVE

To investigate the roles of the vascular endothelial growth factor(VEGF) and endothelin-1(ET-1) in pulmonary vascular remodelling in rats with hypoxia-induced pulmonary hypertension(HPH) and the effect of pinacidil on VEGF and ET-1 in rats with HPH.

METHOD

46 male Wister rats were divided into three groups i.e. control group, hypoxic group and treated group (hypoxic rats treated with pinacidil for 4 weeks). Rat models with chronic HPH were established by chronic hypobaric hypoxia [(10.0 +/- 0.5)% O2, 4 weeks]. The levels of VEGF and ET-1 in serum and the mean pulmonary arterial pressure (mPAP) and the weight ratio of right ventricle (RV)/left ventricle and septum (LV + S) [RV/(LV + S)] were measured and the small pulmonary arterial morphologic changes were observed with morphometric analysis under microscopes in the three groups.

RESULTS

(1) The levels of VEGF[(118.73 +/- 55.40) ng/L] and ET-1[(221.2 +/- 56.2) ng/L] in serum, mPAP [(28.4 +/- 2.8) mm Hg, 1 mm Hg = 0.133 kPa] and RV/(LV + S) (0.296 +/- 0.033) were significantly higher in the hypoxic group than those in the control group (P < 0.01). Morphometry showed that the external diameter of the small pulmonary arteries became smaller and the ratio of vascular wall thickness to external diameter (MT%) (25.70 +/- 2.58)% and ratio of vascular wall area to total area (MA%) (75.300 +/- 5.600)% significantly increased in the hypoxic group. (2) The levels of VEGF[(78.20 +/- 16.45) ng/L] and ET-1[(181.6 +/- 30.5) ng/L] in serum, mPAP[(23.3 +/- 2.6) mm Hg], RV/(LV + S) (0.266 +/- 0.037), MT%(22.10 +/- 2.51)% and MA% (66.900 +/- 0.061)% significantly decreased in the treated group.

CONCLUSION

VEGF and ET-1 play important roles in the development of HPH and pulmonary vascular remodelling. Pinacidil may partly inhibit the development of HPH and pulmonary vascular remodelling by decreasing VEGF and ET-1.

[p53 and vascular endothelial growth factor expression in astrocytoma and their relation to angiogenesis]

OBJECTIVE

This investigation was done to show the pathological importance of p53 protein detection, vascular endothelial growth factor expression (VEGF) and intratumoral microvessel density (IMVD) in astrocytoma.

METHODS

The surgical specimens from 60 brain astrocytoma patients were stained immunohistochemically for p53 and IMVD expressions. IMVD was calculated by labeling the endothelial cells of the blood vessels within the tumor.

RESULTS

p53, VEGF expression were closely correlated with histopathological grade of astrocytoma. Positive p53 protein accumulation and VEGF expression were found in 45.0% (27/60) and 65.0% (39/60) of tumors. The conformation rate of p53 and VEGF was 70.0% (42/60). IMVD was significantly higher in the p53-positive or VEGF-positive tumors than in the negative ones (P < 0.05). Comparing the IMVD in p53+/VEGF+ group, p53-/VEGF+ group and p53+/VEGF- group, p53-/VEGF- group, its difference was also highly significant (P < 0.05).

CONCLUSION

(1) p53 protein detection, VEGF expression and IMVD can be considered as a biological indicator of malignant potential in brain astrocytoma patients and (2) p53 and VEGF expressions, both contributing to the tumor neovascularization, may be helpful in the understanding of intra-tumoral angiogenetic mechanism in the future.

Growth inhibition due to complementation of transforming growth factor-beta receptor type II-defect by human chromosome 3 transfer in human colorectal carcinoma cells

The transforming growth-beta receptor type II (TGF-beta RII) gene is one of the target genes of the DNA mismatch repair (MMR) defect. The human colorectal carcinoma cell line HCT116 has mutations in the hMLH1 gene and in the microsatellite region of the TGF-beta RII gene, both located on the short arm of chromosome 3. Introduction of the wild-type hMLH1 gene on transferred human chromosome 3 restores many characteristics of MMR-deficiency in HCT116. In this study, we determined whether transfer of chromosome 3 into HCT116 also complements the TGF-beta RII gene defect. We compared in vitro growth characteristics between HCT116 and HCT116 with a transferred chromosome 3 (HCT116 + ch3). The growth was suppressed in HCT116 + ch3 compared with parental HCT116. This suppression was abolished by frequent replacement with fresh medium, suggesting that the autocrine TGF-beta-TGF-beta RII system may be responsible for growth suppression. To explore this possibility, we determined several characteristics essential for the autocrine system. We found that HCT116 + ch3 expresses wild-type as well as mutated TGF-beta RII mRNA. In addition, phosphorylation of TGF-beta RI and growth inhibition were observed in HCT116 + ch3 but not in HCT116 by exposure to exogenous TGF-beta. The amount of TGF-beta1 in HCT116 + ch3 cultures was remarkably less than that in the HCT116, suggesting that TGF-beta produced by HCT116 + ch3 cells may be consumed by the cells. The conditioned medium from HCT116 cultures inhibits HCT116 + ch3 growth. This inhibition was neutralized by the anti-TGF-beta antibody. Taken together, these results strongly suggest that the TGF-beta RII gene defect in HCT116 is complemented by a wild-type gene on the transferred chromosome 3 and that HCT116 + ch3 gained the ability to respond to TGF-beta. Simultaneous complementation of defects of a responsible gene and a major target gene by the chromosome transfer is useful to prove the inactivated phenotypes acquired during colorectal tumorigenesis.

[Identification and location of the toxin protein genes in 56 Bacillus thuringiensis isolates]

Polymerase chain reaction was performed to screen Bacillus thuringiensis isolates for cryI, cryIII, and cryV genes with cryI-, cryIII-, and cryV-specific primers respectively. The results indicated that, in the 56 Bt isolates examined, 7 isolates contain cryI gene, 2 isolates contain cryIII gene, and 21 isolates contain both cryI and cryV genes. The cryV gene was located by Southern hybridization in the large plasmid of about 150 MD molecular mass.

Insight into the catalytic mechanism of DNA polymerase beta: structures of intermediate complexes

The catalytic reaction mediated by DNA polymerases is known to require two Mg(II) ions, one associated with dNTP binding and the other involved in metal ion catalysis of the chemical step. Here we report a functional intermediate structure of a DNA polymerase with only one metal ion bound, the DNA polymerase beta-DNA template-primer-chromium(III).2'-deoxythymidine 5'-beta,gamma-methylenetriphosphate [Cr(III).dTMPPCP] complex, at 2.6 A resolution. The complex is distinct from the structures of other polymerase-DNA-ddNTP complexes in that the 3'-terminus of the primer has a free hydroxyl group. Hence, this structure represents a fully functional intermediate state. Support for this contention is provided by the observation of turnover in biochemical assays of crystallized protein as well as from the determination that soaking Pol beta crystals with Mn(II) ions leads to formation of the product complex, Pol beta-DNA-Cr(III).PCP, whose structure is also reported. An important feature of both structures is that the fingers subdomain is closed, similar to structures of other ternary complexes in which both metal ion sites are occupied. These results suggest that closing of the fingers subdomain is induced specifically by binding of the metal-dNTP complex prior to binding of the catalytic Mg(2+) ion. This has led us to reevaluate our previous evidence regarding the existence of a rate-limiting conformational change in Pol beta's reaction pathway. The results of stopped-flow studies suggest that there is no detectable rate-limiting conformational change step.

Regulation of an endogenous locus using a panel of designed zinc finger proteins targeted to accessible chromatin regions. Activation of vascular endothelial growth factor A

We have mapped conserved regions of enhanced DNase I accessibility within the endogenous chromosomal locus of vascular endothelial growth factor A (VEGF-A). Synthetic zinc finger protein (ZFP) transcription factors were designed to target DNA sequences contained within the DNase I-hypersensitive regions. These ZFPs, when fused to either VP16 or p65 transcriptional activation domains, were able to activate expression of the VEGF-A gene as assayed by mRNA accumulation and VEGF-A protein secretion through a range exceeding that induced by hypoxic stress. Importantly, multiple splice variants of VEGF-A mRNA with defined physiological functions were induced by a single engineered ZFP transcription factor. We present evidence for an enhanced activation of VEGF-A gene transcription by ZFP transcription factors fused to VP16 and p65 targeted to two distinct chromosomal sites >500 base pairs upstream or downstream of the transcription start site. Our strategy provides a novel approach for dissecting the requirements for gene regulation at a distance without altering the DNA sequence of the endogenous target locus.

Cloning, characterization, and chromosomal mapping of a human electroneutral Na(+)-driven Cl-HCO3 exchanger

The electroneutral Na(+)-driven Cl-HCO3 exchanger is a key mechanism for regulating intracellular pH (pH(i)) in neurons, glia, and other cells. Here we report the cloning, tissue distribution, chromosomal location, and functional characterization of the cDNA of such a transporter (NDCBE1) from human brain (GenBank accession number AF069512). NDCBE1, which encodes 1044 amino acids, is 34% identical to the mammalian anion exchanger (AE2); approximately 50% to the electrogenic Na/HCO3 cotransporter (NBCe1) from salamander, rat, and humans; approximately 73% to mammalian electroneutral Na/HCO3 cotransporters (NBCn1); 71% to mouse NCBE; and 47% to a Na(+)-driven anion exchanger (NDAE1) from Drosophila. Northern blot analysis of NDCBE1 shows a robust approximately 12-kilobase signal in all major regions of human brain and in testis, and weaker signals in kidney and ovary. This human gene (SLC4A8) maps to chromosome 12q13. When expressed in Xenopus oocytes and running in the forward direction, NDCBE1 is electroneutral and mediates increases in both pH(i) and [Na(+)](i) (monitored with microelectrodes) that require HCO3(-) and are blocked by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). The pH(i) increase also requires extracellular Na(+). The Na(+):HCO3(-) stoichiometry is 1:2. Forward-running NDCBE1 mediates a 36Cl efflux that requires extracellular Na(+) and HCO3(-) and is blocked by DIDS. Running in reverse, NDCBE1 requires extracellular Cl(-). Thus, NDCBE1 encodes a human, electroneutral Na(+)-driven Cl-HCO3 exchanger.

Method of improving optical poling efficiency in polymer films

The alignment of dye molecules in optically poled polymer films is modeled. We point out that when writing beams (fundamental and second harmonic) are linearly polarized with their polarization directions parallel, the majority of the dye molecules in a poled film are axially oriented perpendicular to the writing-beam polarization, whereas the minority are polar oriented parallel to the writing-beam polarization. Only the latter, however, contribute to the second-order nonlinearity of the film. This model is verified by experiments. Based on the model, a new method of improving optical poling efficiency is put forward.

Expression, purification and biochemical characterization of a recombinant phospholipase A2, with anticoagulant activity from Agkistrodon halys Pallas

A cloned cDNA encoding a PLA2 from Agkistrodon halys Pallas was found to have conservative residues Glu53 and Trp70 but with Lys56 and Lys67 substituted by Thr56 and Asp67, respectively, when compared with sequences of other class II PLA2 with anticoagulant activity. It was inserted into a temperature-sensitive bacterial expression vector and effectively expressed in Escherichia coli RR1. The protein was produced as insoluble inclusion bodies and recovered by centrifugation after enzyme digestion. By washing to partial purification, the expression product was refolded and was purified by FPLC superose 12 to appear as a single band in SDS-PAGE. The recombinant protein proved to have obvious enzymatic, anticoagulant and hemolytic activities, which were removed after modification by p-BPB. These findings suggest that the pharmacological activities of this recombinant PLA2 may be related to its catalytic activity and warrant further research on the structure-function relationships of the pharmacological site of the PLA2 from Agkistrodon halys Pallas.

An alternatively spliced long form of Fas apoptosis inhibitory molecule (FAIM) with tissue-specific expression in the brain

The gene encoding Fas apoptosis inhibitory molecule (FAIM) was cloned by differential display using RNA obtained from Fas-resistant and Fas-sensitive primary murine B lymphocytes. FAIM is highly evolutionarily conserved and broadly expressed, suggesting that its gene product plays a key role in cellular physiology. Here we report the identification of a new, longer form of FAIM (FAIM-L) and characterization of the genomic locus that clarifies its origin. The murine FAIM gene is located at chromosome 9f1, a region syntenic to the corresponding location of the human FAIM gene. The gene consists of six exons and contains putative translation initiation sites within exons II and III. The long form of FAIM is generated by all six exons, whereas the originally cloned form of FAIM, now termed FAIM-Short (FAIM-S) is generated from five exons by alternative splicing. FAIM-L is dominantly expressed in the brain whereas FAIM-S is widely expressed in many tissues.

DNA polymerase beta: contributions of template-positioning and dNTP triphosphate-binding residues to catalysis and fidelity

The specific catalytic roles of two groups of DNA polymerase beta active site residues identified from crystal structures were investigated: residues possibly involved in DNA template positioning (Lys280, Asn294, and Glu295) and residues possibly involved in binding the triphosphate moiety of the incoming dNTP (Arg149, Ser180, Arg183, and Ser188). Eight site-specific mutants were constructed: K280A, N294A, N294Q, E295A, R149A, S180A, R183A, and S188A. Two-dimensional NMR analysis was employed to show that the global conformation of the mutants has not been perturbed significantly. Pre-steady-state kinetic analyses with single-nucleotide gapped DNA substrates were then performed to obtain the rate of catalysis at saturating dNTP (k(pol)), the apparent dissociation constant for dNTP (K(d)), catalytic efficiency k(pol)/K(d), and fidelity. Of the three template-positioning residues, Asn294 and Glu295 (but not Lys280) contribute significantly to k(pol). Taken together with other data, the results suggest that these two residues help to stabilize the transition state during catalysis even though they interact with the DNA template backbone rather than directly with the incoming dNTP or the opposite base on the template. Furthermore, the fidelity increases by up to 19-fold for N294Q due to differential k(pol) effects between correct and incorrect nucleotides. Of the four potential triphosphate-binding residues, Ser180 and Arg183 contribute significantly to k(pol) while the effects of R149A are relatively small and are primarily on K(d), and Ser188 appears to play a minimal role in the catalysis by Pol beta. These results identify several residues important for catalysis and quantitate the contributions of each of those residues. The functional data are discussed in relation to the prediction on the basis of available crystal structures.

[Application of cellulose acetate membrane with the technique of impression cytology combined with immunohistochemical staining for detection of dry eye]

PURPOSE

To evaluate the conjunctival cells by impression cytology with cellulose acetate membrane.

METHODS

The expression of the TGF-beta 1 in conjunctival epithelium of 24 patients with dry eye were studied by impression cytology combined with immunohistochemical staining and observed by microscope.

RESULT

The cellulose acetate membrane is very transparent under the microscope. Cell's membrane by TGF-beta 1 staining is clear, cytoplasm brown and nuclei blue.

CONCLUSION

The method of impression cytology with cellulose acetate membrane is simple and has no injury to the ocular surface. Combined with immunohistochemistry staining, it is suitable to observe the conjunctival cells by this technique which has an important value for the examination of the ocular surface disease.

[Laboratory study on protective and therapeutic effects of pinacidil on pulmonary vascular remodeling in rats with hypoxia-induced pulmonary hypertension]

OBJECTIVE

To investigate the protective and therapeutic effects of pinacidil on hypoxia-induced pulmonary hypertension(HPH) and pulmonary vascular remodeling.

METHODS

46 male Wister rats were divided into control group, hypoxic group and treated group (hypoxic rat treated with pinacidil for 4 weeks). Rat models with chronic HPH were established by chronic hypobaric hypoxia [(10 +/- 0.5)% O2, 4 weeks)]. The mean pulmonary arterial pressure (mPAP) and right ventricle/left ventricle and septum [RV/(LV + S)] were measured and the small pulmonary arterial morphologic changes were observed with morphmetric analysis under microscopes in three groups.

RESULTS

(1) The level of mPAP(28.4 +/- 2.8) mm Hg and RV/(LV + S) (0.30 +/- 0.03) were significantly higher in the hypoxic group than (16.2 +/- 1.8) mm Hg and (0.22 +/- 0.03) in control group respectively (P < 0.01). Morphometry investigation showed that the external diameter became smaller and that ratio of vascular wall thickness to external diameter (MT%) (25.7 +/- 2.6)% and ratio of vascular wall area to total area (MA%) (75.3 +/- 5.6)% significantly increased in the hypoxic group. (2) The mPAP(23.3 +/- 2.6) mm Hg, RV/(LV + S) (0.27 +/- 0.04) and pulmonary vascular pathologic changes MT%(22.1 +/- 2.5)% and MA% (67.0 +/- 6.1)% significantly decreased in the treated group, indicating that pinacidil inhibited HPH and hypoxia-induced thickening and muscularization of small pulmonary arteria.

CONCLUSION

Pinacidil may partly prevent the development of HPH and pulmonary vascular remodeling.

Regulation of yeast ectoapyrase ynd1p activity by activator subunit Vma13p of vacuolar H+-ATPase

CD39-like ectoapyrases are involved in protein and lipid glycosylation in the Golgi lumen of Saccharomyces cerevisiae. By using a two-hybrid screen, we found that an activator subunit (Vma13p) of yeast vacuolar H(+)-ATPase (V-ATPase) binds to the cytoplasmic domain of Ynd1p, a yeast ectoapyrase. Interaction of Ynd1p with Vma13p was demonstrated by direct binding and co-immunoprecipitation. Surprisingly, the membrane-bound ADPase activity of Ynd1p in a vma13Delta mutant was drastically increased compared with that of Ynd1p in VMA13 cells. A similar increase in the apyrase activity of Ynd1p was found in a vma1Delta mutant, in which the catalytic subunit A of V-ATPase is missing, and the membrane peripheral subunits including Vma13p are dissociated from the membranes. However, the E286Q mutant of VMA1, which assembles inactive V-ATPase complex including Vma13p in the membrane, retained wild type levels of Ynd1p activity, demonstrating that the presence of Vma13p rather than the function of V-ATPase in the membrane represses Ynd1p activity. These results suggest that association of Vma13p with the cytoplasmic domain of Ynd1p regulates its apyrase activity in the Golgi lumen.