Friction and Adhesion between C60 Single Crystal Surfaces and AFM Tips: Effects of the Orientational Phase Transition

We have investigated the nanotribological properties of C60 single crystal (111) and (100) surfaces around its orientational order-disorder phase transition temperature, approximately 260 K, by atomic force microscopy and frictional force microscopy (AFM/FFM) in high vacuum. Results show that for both surfaces across the phase transition temperature, the friction force and the adhesive force between a C60 coated AFM tip and the C60 crystal surfaces exhibit discontinuous behavior. The friction force within the applied external load range in the low temperature phase is significantly larger than that in the high temperature phase, with no obvious change in the slope of the friction force curves (the friction coefficient) in the low and high temperature phases. The abrupt change in friction was found to be caused mainly by the abrupt change in adhesion, which, in turn, can be qualitatively understood through changes in the van der Waals interaction and the short-range Coulomb interaction associated with the structural changes across the phase transition. Compared to most other degrees of freedom, the rotation of C60 molecules was found to have little effect on friction and is an ineffective energy dissipation channel.

[Effects of plasma catecholamines contents on acute cerebral hemorrhage treated with nao yi-an granule]

In order to investigate the efficacy mechanism of Nao Yi-an(NYA) granule on acute cerebral hemorrhage(ACH), 38 cases of ACH were treated with NYA granule(NYA group) or with Western Medicine (WM group). The contents of their plasmal NE, E, and DA before and after treatments were observed. The results showed that the contents of the plasmal NE, E and DA increase remarkably, compared with those of normal control group(P < 0.01), and accompanied by the increase of volume of hemorrhage or the gravity of the disease. After treatment, the contents of the plasmal NE, E and DA in NYA group are notably lower than those before the treatment(P < 0.01), but in WM group, they are not significantly lower than those before the treatment(P > 0.05), and they are strikingly lower in NYA group than in WM group. It is indicated that the NYA group can effectively decrease the contents of plasmal NE, E and DA, to remove cerebrovascular spasm, to relieve cerebral edema, to improve microcirculation of brain tissue, to increase blood and energy supplies, anticerebral secondary ischemia and hypoxia and improve the clinical effects.

Monitoring adenoviral DNA delivery, using a mutant herpes simplex virus type 1 thymidine kinase gene as a PET reporter gene

Current gene therapy protocols often suffer from an inability to monitor the site, level and persistence of gene expression following somatic DNA delivery. Herpes simplex virus 1 thymidine kinase (HSV1-tk) is currently under intensive investigation as a reporter gene for in vivo imaging of reporter gene expression. The presence of the HSV1-tk reporter gene is repetitively and non-invasively monitored by systemic injection of positron-emitting, radionuclide-labeled thymidine analogues or acycloguanosine HSV1-TK substrates and subsequent detection, by positron emission tomography, of trapped, phosphorylated product. To improve the efficacy of the HSV1-tk PET reporter gene system, both alternative substrates and mutations in the HSV1-tk gene have been described. We used a replication defective adenovirus to deliver the HSV1-sr39tk mutant enzyme and the wild-type HSV1-tk enzyme to mice. HSV1-sr39TK demonstrates greater sensitivity than wild-type HSV1-TK enzyme in vivo, using 9-[(4-[(18)F]fluoro-3-hydroxymethylbutyl)guanine as probe, following adenovirus-mediated hepatic expression in mice. Using this adenoviral delivery system, the location, magnitude and duration of HSV1-sr39tk PET reporter gene expression could be non-invasively, quantitatively and repetitively monitored for over 3 months by microPET.

[Protection of naoyi-an granule in ischemic brain injury secondary to intracerebral hemorrhage in rats]

AIM

To explore the protective effect and its mechanism of the traditional Chinese medicine complex, naoyi-an granule(NYAG), on intracerebral hemorrhage(ICH) in rats.

METHODS

Collagenase-induced ICH rats were used. Inducible nitric oxide synthase(iNOS) activity of ischemic cerebral cortex surrounding the intracerebral hematoma was assayed by monitoring the conversion of L-3H-arginine to L-3H-citrulline. Pathologic changes in the same area were observed with transmission electron microscope on the 2nd day, the 4th day and the 7th day after ICH.

RESULTS

The iNOS activities of NYA-treated group decreased remarkably(P < 0.01) compared with those of the saline-treated group. Ultrastructural observation also indicated that NYAG ameliorated the brain edema, cell degeneration and necrosis.

CONCLUSIONS

The inhibitory effect of NYAG on iNOS activity may be related to its protection against ischemic brain injury secondary to ICH.

[Clinical analysis of completion pneumonectomy on lung cancer]

BACKGROUND

To explore the indications, operative technique and outcome of completion pneumonectomy for lung cancer .

METHODS

Thirty-two cases of lung cancer underwent completion pneumonectomy. The 5-year survival rate was calculated with a Kaplan-Meier model and compared with that of the 165 standard pneumonectomy on lung cancer during the same period.

RESULTS

Extrapleural dissection was performed in 8 cases, intrapericardial vessel ligation was in 16, chest wall was resected in 1, and the left atrium was partly resected in 1. There was no operative mortality. The postoperative complication incidence was 21. 9% ( 7/ 32) , which was significantly higher than that for standard pneumonectomy ( 5. 5%, 9/ 165) during the same period ( P < 0. 05) . The overall 5-year survival rate was 21. 9%, which compared favorably with 25. 7% of the standard pneumonectomy during the same period ( P > 0. 05) .

CONCLUSIONS

The indications for completion pneumonectomy include local recurrence, second primary lung cancer and lung cancer developed after pneumonectomy for benign disease. Although the operative technique is complex and the postoperative complication incidence is high, the 5-year survival rate can be the same as that of standard pneumonectomy.

[The influence of antidepressive therapy on short-term prognosis in elderly patients with unstable angina and depression]

OBJECTIVE

To observe the influence of antidepressive therapy on short-term prognosis in elderly unstable angina pectoris patients with depression.

METHODS

76 unstable angina pectoris patients were random into a therapy group (38) and control group (38). Patients in the therapy group were treated with psychotherapy and administration of antidepressant Fluoxetine (Prozac Eli Lilly, USA) 20mg once a day on the basis of regular cardiac medicine therapy for 12 weeks, Patients in the control group were only treated with regular cardiac medicine therapy.

RESULTS

Myocardial ischaemia in the therapy group was significantly improved. The recurrence rate of angina pectoris and incidence ratio of acute myocardial infarction in the therapy group were low. There was significant difference in comparison with the control group (P < 0.05).

CONCLUSION

Antidepression can significantly improve the short-term prognosis in elderly unstable angina pectoris patients.

The transcription factor GATA4 is activated by extracellular signal-regulated kinase 1- and 2-mediated phosphorylation of serine 105 in cardiomyocytes

The zinc finger-containing transcription factor GATA4 has been implicated as a critical regulator of multiple cardiac-expressed genes as well as a regulator of inducible gene expression in response to hypertrophic stimulation. Here we demonstrate that GATA4 is itself regulated by the mitogen-activated protein kinase signaling cascade through direct phosphorylation. Site-directed mutagenesis and phospho-specific GATA4 antiserum revealed serine 105 as the primary site involved in agonist-induced phosphorylation of GATA4. Infection of cultured cardiomyocytes with an activated MEK1-expressing adenovirus induced robust phosphorylation of serine 105 in GATA4, while a dominant-negative MEK1-expressing adenovirus blocked agonist-induced phosphorylation of serine 105, implicating extracellular signal-regulated kinase (ERK) as a GATA4 kinase. Indeed, bacterially purified ERK2 protein directly phosphorylated purified GATA4 at serine 105 in vitro. Phosphorylation of serine 105 enhanced the transcriptional potency of GATA4, which was sensitive to U0126 (MEK1 inhibitor) but not SB202190 (p38 inhibitor). Phosphorylation of serine 105 also modestly enhanced the DNA binding activity of bacterially purified GATA4. Finally, induction of cardiomyocyte hypertrophy with an activated MEK1-expressing adenovirus was blocked with a dominant-negative GATA4-engrailed-expressing adenovirus. These results suggest a molecular pathway whereby MEK1-ERK1/2 signaling regulates cardiomyocyte hypertrophic growth through the transcription factor GATA4 by direct phosphorylation of serine 105, which enhances DNA binding and transcriptional activation.

Tissue-specific GATA factors are transcriptional effectors of the small GTPase RhoA

Rho-like GTPases play a pivotal role in the orchestration of changes in the actin cytoskeleton in response to receptor stimulation, and have been implicated in transcriptional activation, cell growth regulation, and oncogenic transformation. Recently, a role for RhoA in the regulation of cardiac contractility and hypertrophic cardiomyocyte growth has been suggested but the mechanisms underlying RhoA function in the heart remain undefined. We now report that transcription factor GATA-4, a key regulator of cardiac genes, is a nuclear mediator of RhoA signaling and is involved in the control of sarcomere assembly in cardiomyocytes. Both RhoA and GATA-4 are essential for sarcomeric reorganization in response to hypertrophic growth stimuli and overexpression of either protein is sufficient to induce sarcomeric reorganization. Consistent with convergence of RhoA and GATA signaling, RhoA potentiates the transcriptional activity of GATA-4 via a p38 MAPK-dependent pathway that phosphorylates GATA-4 activation domains and GATA binding sites mediate RhoA activation of target cardiac promoters. Moreover, a dominant-negative GATA-4 protein abolishes RhoA-induced sarcomere reorganization. The identification of transcription factor GATA-4 as a RhoA mediator in sarcomere reorganization and cardiac gene regulation provides a link between RhoA effects on transcription and cell remodeling.

Noninvasive, quantitative imaging in living animals of a mutant dopamine D2 receptor reporter gene in which ligand binding is uncoupled from signal transduction

The dopamine D2 receptor (D2R) has been used in adenoviral delivery systems and in tumor cell xenografts as an in vivo reporter gene. D2R reporter gene expression has been non-invasively, repetitively and quantitatively imaged by positron emission tomography (PET), following systemic injection of a positron-labeled ligand (3-(2'-[18F]-fluoroethyl)-spiperone; FESP) and subsequent D2R-dependent sequestration. However, dopamine binding to the D2R can modulate cyclic AMP levels. For optimal utilization of D2R as a reporter gene, it is important to uncouple ligand-binding from Gi-protein-mediated inhibition of cAMP production. Mutation of Asp80 or Ser194 produces D2Rs that still bind [3H]spiperone in transfected cells. The D2R80A mutation completely eliminates the ability of the D2R to suppress forskolin-stimulated cAMP accumulation in response to dopamine, in cells transfected with a D2R80A expression plasmid and in cells infected with replication-defective adenovirus expressing D2R80A. The D2R194A mutation substantially reduces, but does not completely eliminate, dopamine modulation of cAMP levels. Cultured cells infected with adenoviruses expressing D2R and D2R80A demonstrated equivalent [3H]spiperone binding activity. Moreover, hepatic FESP sequestration is equivalent, following intravenous injection of adenoviruses expressing D2R and D2R80A. The D2R80A mutant, which can no longer modulate cAMP levels following ligand binding, has full capability as a PET reporter gene.

Direct correlation between positron emission tomographic images of two reporter genes delivered by two distinct adenoviral vectors

Biodistribution, magnitude and duration of a therapeutic transgene's expression may be assessed by linking it to the expression of a positron emission tomography (PET) reporter gene (PRG) and then imaging the PRG's expression by a PET reporter probe (PRP) in living animals. We validate the simple approach of co-administering two distinct but otherwise identical adenoviruses, one expressing a therapeutic transgene and the other expressing the PRG, to track the therapeutic gene's expression. Two PET reporter genes, a mutant herpes simplex virus type 1 thymidine kinase (HSV1-sr39tk) and dopamine-2 receptor (D(2)R), each regulated by the same cytomegalovirus (CMV) promoter, have been inserted into separate adenoviral vectors (Ad). We demonstrate that cells co-infected with equivalent titers of Ad-CMV-HSV1-sr39tk and Ad-CMV-D(2)R express both reporter genes with good correlation (r(2) = 0.93). Similarly, a high correlation (r(2) = 0.97) was observed between the expression of both PRGs in the livers of mice co-infected via tail-vein injection with equivalent titers of these two adenoviruses. Finally, microPET imaging of HSV1-sr39tk and D(2)R expression with 9-(4-[(18)F]fluoro-3-hydroxymethylbutyl) guanine ([(18)F]FHBG) and 3-(2-[(18)F]fluoroethyl)spiperone ([(18)F]FESP), utilizing several adenovirus-mediated delivery routes, illustrates the feasibility of evaluating relative levels of transgene expression in living animals, using this approach.

[Clinical significance of c-myc oncogene amplification in primary hepatocellular carcinoma by interphase fluorescence in situ hybridization]

OBJECTIVE

To investigate the relationships between c-myc oncogene amplification in primary hepatocellular carcinoma (HCC) and its clinical prognosis.

METHODS

To detect c-myc oncogene amplification in 100 cases with primary HCC and in 6 cases with satellite nodes by interphase fluorescence in situ hybridization (FISH).

RESULTS

c-myc amplification was detected in 92 of 100 (92%) cases with HCC, 37 of which (37%) showed high copy amplification (HC), 55 (55%) low copy amplification (LC) and 8 (8%) single copy or no amplification (SC). There wasn't statistically different significance between the frequency of c-myc amplification and clinical stage and tumor size, and pathological types (P > 0.05), however, in the 90 follow-up resected cases, the one-year rates of recurrence in HC, LC and SC were 70.6% (24/34), 39.6% (19/48) and 12.5% (1/8) respectively (P < 0.05) but the recurrence rates after more than one year were 14.70% (5/34), 14.6% (7/48) and 0 (0/8) respectively (P > 0.05). Meanwhile, two-year survival rate of patients with HC was significantly lower in comparison with those with LC and SC (P = 0.001).

CONCLUSIONS

There is a high frequency of c-myc oncogene amplification in primary HCC and the fact that the patients with HC showed poorer prognosis indicates that the level of c-myc oncogene amplification may be a sensitive index in the prognosis of HCC.

The transcription factors GATA4 and GATA6 regulate cardiomyocyte hypertrophy in vitro and in vivo

The zinc finger-containing transcription factors GATA4 and GATA6 are important regulators of basal and inducible gene expression in cardiac and smooth muscle cell types. Here we demonstrate a direct functional role for GATA4 and GATA6 as regulators of cardiomyocyte hypertrophic growth and gene expression. To model the increase in endogenous GATA4 and GATA6 transcriptional activity that occurs in response to hypertrophic stimulation, each factor was overexpressed in cardiomyocytes using recombinant adenovirus. Overexpression of either GATA4 or GATA6 was sufficient to induce cardiomyocyte hypertrophy characterized by enhanced sarcomeric organization, a greater than 2-fold increase in cell surface area, and a significant increase in total protein accumulation. In vivo, transgenic mice with 2.5-fold overexpression of GATA4 within the adult heart demonstrated a slowly progressing increase in heart to body weight ratio, histological features of cardiomyopathy, and activation of hypertrophy-associated genes, suggesting that GATA factors are sufficient regulators of cardiomyocyte hypertrophy in vitro and in vivo. To evaluate the requirement of GATA factors as downstream transcriptional mediators of hypertrophy, a dominant negative GATA4-engrailed repressor fusion-encoding adenovirus was generated. Expression of GATA4-engrailed blocked GATA4- and GATA6-directed transcriptional responses and agonist-induced cardiomyocyte hypertrophy, demonstrating that cardiac-expressed GATA factors are necessary mediators of this process.

[Frequent chromosomal gain of 4q and loss of 1p in primary nasopharyngeal carcinoma]

OBJECTIVE

To reveal the genetic changes of nasopharyngeal carcinoma (NPC) in Cantonese.

METHODS

Comparative genomic hybridization (CGH) was performed on 17 primary NPC biopsy specimens to find out any gain or loss of genetic material.

RESULTS

A novel copy number gain on chromosome 4q and loss of chromosome 1p were found at high frequency (> 50%). The other more common genetic alterations included gain of chromosomes 4q, 12q, and 1q as well as loss of chromosomes 1p, 3p, 11q, 14q, 15q, 13q, Xq, 9q, 10p, 10q, and 16q.

CONCLUSION

Current analysis has revealed a comprehensive profile of the chromosomal changes in NPC. Frequently altered loci may encode oncogenes or tumor suppressor genes involved in the development of primary NPC.

High-performance liquid chromatography multiplex detection of two single nucleotide mutations associated with hereditary hemochromatosis

High-performance liquid chromatography (HPLC) has been applied to the multiplex detection of the two single nucleotide mutations commonly found in hereditary hemochromatosis (HH). HH is associated with a major G to A transition at position 845 (mutation Cys282Tyr) and a minor C to G transition at position 187 (mutation His63Asp) in the cDNA of the HFE gene. Two detection assays were developed based on HPLC analysis of restriction fragment length polymorphism (RFLP) or single nucleotide extension (SNE) products following multiplex PCR amplification. RFLP genotypes the two sites as dsDNA fragments of different lengths generated by restriction enzymes Rsa I/Bcl I. SNE extends primers 5'-adjacent to the sites of interest with a dideoxynucleotide triphosphate (ddNTP) to generate extended ssDNA. The identity of the added ddNTP reveals the identity of the original possible mutation site(s). Application of these methods with HPLC analysis provides simple and reliable genotyping for HH and can be applied to other single nucleotide polymorphism studies.

Analysis of genetic alterations in primary nasopharyngeal carcinoma by comparative genomic hybridization

To identify genetic alterations associated with the development and progression of human nasopharyngeal carcinoma (NPC), 57 tumors were analyzed by comparative genomic hybridization (CGH). In 47 cases, chromosomal imbalances were found. Several recurrent chromosomal abnormalities were identified in the present study. The most frequently detected chromosomal gains involved chromosome arms 12q (24 cases, 51%), 4q (17 cases, 36%), 3q (16 cases, 34%), 1q (15 cases, 32%), and 18q (15 cases, 32%). Common regions of gain involved 12q13--q15, 4q12--q21, and 3q21--q26. High-copy-number increases of chromosomal materials were detected in four chromosomal regions, 3q21--q26.2, 4p12--q21, 8p, and 12q14--q15. The most frequently detected loss of chromosomal materials involved chromosome arms 16q (26 cases, 55%), 14q (21 cases, 45%), 1p (20 cases, 43%), 3p (20 cases, 43%), 16p (19 cases, 40%), 11q (17 cases, 36%), and 19p (16 cases, 34%). The most common regions of loss involved 14q24--qter, 1pter--p36.1, 3p22--p21.3, 11q21--qter, and the distal region of 19p. Genomic alterations detected by CGH were compared and found to be largely consistent with those identified in banding analysis and loss of heterozygosity studies. However, several previously unrecognized recurrent alterations were also identified in the present study, including gain of 4q and 18q, and loss of 16q, 14q, and 19p. In addition, gain of 1q, 8q, 18q, and loss of 9q showed a statistically significant association with advanced clinical stages (P < 0.05). Identification of recurrent sites of chromosomal gain and loss identify regions of the genome that may contain oncogenes or tumor suppressor genes, respectively, which may be involved in the tumorigenesis of NPC. Published 2000 Wiley-Liss, Inc.

Novel chromosomal alterations detected in primary nasopharyngeal carcinoma by comparative genomic hybridization

OBJECTIVE

To gain a better understanding of genetic changes in Cantonese nasopharyngeal carcinoma (NPC).

METHODS

Comparative genomic hybridization (CGH) was performed on 17 primary nasopharyngeal carcinomas.

RESULTS

A novel copy number gain an chromosome 4q and loss of chromosome 1p were found at a high frequency (> 50%).

CONCLUSIONS

Current analysis revealed a comprehensive profile of the chromosomal regions showing gain of chromosomes 4q, 12q, and 1q as well as loss of chromosomes 1p, 3p, 11q, 14q, 15q, 13q, Xq, 9q, 10p, 10q, and 16q. Frequently altered loci may encode oncogenes or tumor suppressor genes involved in the development of primary NPC.

[Fine mapping of the loss of heterozygosity for chromosome 1pter-p36.11 in nasopharyngeal carcinoma]

OBJECTIVE

To construct a detailed mapping of the Chromosome 1pter-p36.11 deleted region (63.4 cM) in nasopharyngeal carcinoma (NPC) by polymerase chain reaction-loss of heterozygosity (PCR-LOH) analysis for the further research of NPC-related gene(s).

METHODS

Biopsies from 47 cases of NPC patients were studied. DNA extracted from separated cancer cells and their corresponding non-cancer lymphocytes were amplified with PCR, followed by the analysis of LOH and microsatellite instability (MI) for 20 loci spanning Chromosome 1pter-p36.11 region with an average interval of 3.0 cM.

RESULTS

82.2% of NPC cases (37/47) showed at least one loci of LOH. The highest frequency of LOH was found at loci D1S234 on 1p36.13 (50.0%), with the LOH at loci D1S2644 on 1p36.22 slightly less (37.5%). The occurrence of LOH at D1S234 showed no significant difference for the cases at early stage and at advanced stage [60% (9/15) vs 50.0% (8/16) respectively, P > 0.05]. High frequencies of MI were detected at D1S243 on 1p36.33 (37.5%) and D1S199 on 1p36.21 (30.2%).

CONCLUSIONS

There are two common deletion regions: one localized at 1p36.13 (D1S234, 2.0 cM) and the other at 1p36.22 (D1S436-D1S2644, 6.3 cM), with a MI loci at D1S199 between them. This suggests that one or more putative tumor suppressor gene(s) related to the early stage of NPC tumorigenesis may be encompassed in this zone.

Cu(II)/H2O2-induced DNA damage is enhanced by packaging of DNA as a nucleosome

Copper is a physiologically important, redox-active metal that may be involved in endogenous DNA damage and mutagenesis. To understand the factors that affect the location and quantity of copper-induced oxidative DNA damage in cells, we used the 5S rDNA nucleosome as a model to assess the effect of chromatin structure on DNA damage produced by Cu(II)/H2O2. Packaging of DNA into a nucleosome increased the extent of Cu(II)/H2O2-induced strand breaks by a factor of 2, while the extent of base lesions sensitive to Fpg and endo III glycosylases increased 8-fold. We also observed that Cu(II)/H2O2 caused slightly more strand breaks than base lesions in isolated 5S rDNA (ratio of base lesions to strand breaks of approximately 0.6), while base lesions outnumbered strand breaks by a factor of 3-4 when the DNA was incorporated into a nucleosome. Apart from several sites of enhanced or diminished DNA damage, there were no major changes in the sequence selectivity of Cu(II)/H2O2, and there was no apparent footprinting effect associated with nucleosome structure, such as that observed with the Fe(II)-EDTA complex. Possible mechanisms for explaining these observations include (1) an increase in Cu(II) concentration in the vicinity of nucleosomal DNA caused by binding of Cu to histone proteins or (2) increased reactivity or accessibility of nucleobases caused by DNA conformational changes associated with nucleosome structure. The enhancement of Cu(II)/H2O2-induced DNA damage in nucleosomes stands in contrast to the protective effect afforded DNA by proteins in chromatin against radiation-induced DNA damage.

[Purification of recombinant hEGF expressed in yeast Pichia pastoris and the study on its characters]

OBJECTIVE

To obtain recombinant human epidermal growth factor(hEGF) that can be used in animal experiments and clinical trial.

METHOD

Chemically synthesized hEGF gene was expressed in Yeast Pichia pastoris and the secretory hEGF was purified by Phenysepharose 6 Fast Flow(high sub), Q-sepharose High Performance, and Superdex 30 chromatography, and its characters were studied by respective methods.

RESULTS

The purified hEGF doesn't contain pyrogen, endotoxin, or yeast chromosome DNA and the purity reached 98%. The recombinant human EGF has correct molecular weight, pI, N-terminal amino acids sequences, peptide map, ultraviolet spectrum and well-biological activity.

CONCLUSION

The purified hEGF is in accord with the requirements for animal experiments and clinical trial which provides the basis of preparing EGF agents for clinical test.

Targeted inhibition of calcineurin attenuates cardiac hypertrophy in vivo

The Ca(2+)-calmodulin-activated Ser/Thr protein phosphatase calcineurin and the downstream transcriptional effectors of calcineurin, nuclear factor of activated T cells, have been implicated in the hypertrophic response of the myocardium. Recently, the calcineurin inhibitory agents cyclosporine A and FK506 have been extensively used to evaluate the importance of this signaling pathway in rodent models of cardiac hypertrophy. However, pharmacologic approaches have rendered equivocal results necessitating more specific or genetic-based inhibitory strategies. In this regard, we have generated Tg mice expressing the calcineurin inhibitory domains of Cain/Cabin-1 and A-kinase anchoring protein 79 specifically in the heart. DeltaCain and DeltaA-kinase-anchoring protein Tg mice demonstrated reduced cardiac calcineurin activity and reduced hypertrophy in response to catecholamine infusion or pressure overload. In a second approach, adenoviral-mediated gene transfer of DeltaCain was performed in the adult rat myocardium to evaluate the effectiveness of an acute intervention and any potential species dependency. DeltaCain adenoviral gene transfer inhibited cardiac calcineurin activity and reduced hypertrophy in response to pressure overload without reducing aortic pressure. These results provide genetic evidence implicating calcineurin as an important mediator of the cardiac hypertrophic response in vivo.

Analysis of genetic alterations in primary nasopharyngeal carcinoma by comparative genomic hybridization

To identify genetic alterations associated with the development and progression of human nasopharyngeal carcinoma (NPC), 57 tumors were analyzed by comparative genomic hybridization (CGH). In 47 cases, chromosomal imbalances were found. Several recurrent chromosomal abnormalities were identified in the present study. The most frequently detected chromosomal gains involved chromosome arms 12q (24 cases, 51%), 4q (17 cases, 36%), 3q (16 cases, 34%), 1q (15 cases, 32%), and 18q (15 cases, 32%). Common regions of gain involved 12q13--q15, 4q12--q21, and 3q21--q26. High-copy-number increases of chromosomal materials were detected in four chromosomal regions, 3q21--q26.2, 4p12--q21, 8p, and 12q14--q15. The most frequently detected loss of chromosomal materials involved chromosome arms 16q (26 cases, 55%), 14q (21 cases, 45%), 1p (20 cases, 43%), 3p (20 cases, 43%), 16p (19 cases, 40%), 11q (17 cases, 36%), and 19p (16 cases, 34%). The most common regions of loss involved 14q24--qter, 1pter--p36.1, 3p22--p21.3, 11q21--qter, and the distal region of 19p. Genomic alterations detected by CGH were compared and found to be largely consistent with those identified in banding analysis and loss of heterozygosity studies. However, several previously unrecognized recurrent alterations were also identified in the present study, including gain of 4q and 18q, and loss of 16q, 14q, and 19p. In addition, gain of 1q, 8q, 18q, and loss of 9q showed a statistically significant association with advanced clinical stages (P < 0.05). Identification of recurrent sites of chromosomal gain and loss identify regions of the genome that may contain oncogenes or tumor suppressor genes, respectively, which may be involved in the tumorigenesis of NPC. Published 2000 Wiley-Liss, Inc.

Comparison of arrhythmias among different left ventricular geometric patterns in essential hypertension

The differences of arrhythmias among distinct left ventricular geometric patterns in the patients with essential hypertension were studied. 179 patients with essential hypertension received 24 h dynamic ECG recording, ambulatory blood pressure monitoring, echocardiography examination, etc. According to the examinations, left ventricular geometric patterns and arrhythmias were identified. The comparison of morbidity of arrhythmias between the left ventricular remodeling group and the normal geometric pattern group was performed. The multiple stepwise regression analysis was carried out to identify the independent determinants of arrhythmias. After these predictors were controlled or adjusted, the severity of arrhythmias among different left ventricular geometric patterns was compared. It was found that the morbidity of atrial arrhythmia, ventricular arrhythmia and complex ventricular arrhythmias in the left ventricular remodeling group was significantly higher than in the normal geometric pattern group respectively. There were many independent factors influencing on arrhythmias in essential hypertension. Of all these factors, some indices of left ventricular anatomic structure, grade of hypertension, left atrial inner dimension, E/A, diastolic blood pressure load value at night and day average heart rate and so on were very important. After the above-mentioned factors were adjusted, the differences of the orders of arrhythmias between partial geometric patterns were reserved, which resulted from the differences of the geometric patterns. Many factors contributed to arrhythmias of essential hypertension, such as grade of hypertension, LVMI, LA, PWT and so on. The severity of arrhythmias was different in different left ventricular geometric patterns.

[Effects of temperature, relative humidity and pH on germination of chalkbrood fungus, Ascosphaera apis spore]

Studies on the effects of environmental temperature, relative humidity and pH-value on the germination of Ascosphaera apis spore at the stages of activation, enlargement and germ-tube production showed that the germination was found to be independent of temperature within the range of 15-40 degrees C was and 25-40 degrees C, respectively at the stage of activation and enlargement, but closely correlated with the temperature within the range of 25-37 degrees C at the stage of germ-tube production, with the optimum range of 31-35 degrees C. Relative humidity below 80% inhibited spore germination. pH value within the range of 5-7.8 did not affect the spore germination significantly, but pH < 5 reduced the enlargement and germ-tube production drastically. The results indicated that A. apis is a highly specialized pathogen for the life in honeybee larvae.

[Stress-corrosion test of TIG welded CP-Ti]

In this study TIG (Tungsten Inert Gas) welded CP-Ti were subjected to stress-corrosion test under 261 MPa in artificial saliva of 37 degrees C for 3 months. No significant difference was noted on mechanical test (P > 0.05). No color-changed and no micro-crack on the sample's surface yet. These results indicate that TIG welded CP-Ti offers excellent resistance to stress corrosion.

Recurrent chromosome changes in 62 primary gastric carcinomas detected by comparative genomic hybridization

Comparative genomic hybridization (CGH) has been applied to detect recurrent chromosome alterations in 62 primary gastric carcinomas. Several nonrandom chromosomal changes, including gains of 8q (31 cases, 50%), 20q (29 cases, 47%) with a minimum gain region at 20q11. 2-q12, 13q (21 cases, 34%) with a minimum gain region at 13q22, and 3q (19 cases, 31%) were commonly observed. The regions most frequently lost included: 19p (23 cases, 37%), 17p (21 cases, 33%), and 1p (14 cases, 23%). High copy number gain (DNA sequence amplification) was detected in 6 cases. Amplification of 8q23-q24.2 and 20q11.2-q12 were observed in 3 cases. Gain of 20q and loss of 19p were confirmed by fluorescence in situ hybridization using corresponding bacterial artificial chromosomes (BAC) clones from those regions. The gain and loss of chromosomal regions identified in this study provide candidate regions involved in gastric tumorigenesis.

[Clinical investigation of effects of bizhongxiao decoction (BZX) on rheumatoid arthritis on active phase]

Ninety-six patients with rheumatoid arthritis(RA) on active phase were divided into BZX-treated group(BZXG) and methotrexate-treated group(MTXG). The results showed that after 1-month treatment, symptoms and signs, such as joint tenderness, arthralgia, arthroncus, of patients in BZXG improved notably(P < 0.01 or P < 0.05), while those of patients in MTXG did not improve, there was significant difference between these two groups(P < 0.01 or P < 0.05). After 3-month treatment, these symptoms and signs improved in both groups(P < 0.01 or P < 0.05), but BZX had a better effect than MTX. ESR, CRP, RF, C3, IgG, IgA and IgM decreased significantly in both groups after treatment(P < 0.01 or P < 0.05), ESR, CRP in BZXG decreased more and faster than those in MTXG. In BZXG the obviously efficient rat was 70%, the total efficacy rate was 94%, while in MTXG was 52% and 87% respectively. It is indicated that BZX can improve symptoms and signs of patients with RA, has better and faster effects on acute phase reaction than MTX; and it has anti-immunologic effects similar to MTX, and has no obvious side effect.

[Correlation of microsatellite alterations on chromosome 9 and oncogenesis,metastasis in NSCLC]

BACKGROUND

To investigate the relationship among microsatellite alterations on chromosome 9(9p) and the oncogenesis,metastasis of non-small cell lung cancer (NSCLC).

METHODS

Two microsatellite markers,IFNA and D9S171,were analyzed in 32 cases of NSCLC by polymerase chain reaction-based silver-staining assay.

RESULTS

Of 32 cases of NSCLC,14(43.8%) had microsatellite alterations.The alteration frequency was 64.7% in NSCLC with lymph node metastasis,and 20% in those without lymph node metastasis.There was significant difference between the two groups.None of benign lung tissues showed microsatellite alterations.

CONCLUSIONS

Microsatellite alteration on chromosome 9p in NSCLC appears to be a common and specific event,and may be a valuable molecular marker for determination of early diagnosis and metastasis of NSCLC.

Recurrent chromosome alterations in hepatocellular carcinoma detected by comparative genomic hybridization

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and has a very poor prognosis. Fifty primary HCC cases have been analyzed in the present study to explore the association between genomic alteration in primary HCC and clinical features. Several recurrent chromosomal abnormalities were identified in this study. The most frequently detected chromosomal gains involved chromosome arms 1q (33/50 cases, 66%), 8q (24/50 cases, 48%), and 20q (10/50 cases, 20%). High-copy-number amplifications involving 1q (4 cases), 8q (3 cases), and 20q (3 cases) were detected, and a minimum overlapping amplified region at 1q12-q22 was identified. The most frequently detected loss of chromosomal material involved 16q (35/50 cases, 70%), 17p (26/50 cases, 52%), 19p (21/50 cases, 42%), 4q (20/50 cases, 40%), 1p (18/50 cases, 36%), 8p (16/50 cases, 32%), and 22q (14/50 cases, 28%). The associations between genomic alterations detected in the present study and clinical features including clinical stage, tumor size, HBV infection, chronic liver disease, and liver cirrhosis were explored. Our CGH results suggest that the gain of 20q and deletion of 8p are late genetic alterations in HCC, because the incidence of these alterations was obviously increased in the advanced clinical stages. Another finding showed that loss of 8p and gain of 8q and 20q are associated with tumor size. The recurrent gain and loss of chromosomal regions identified in this study provide candidate regions that may contain oncogenes or tumor suppressor genes respectively involved in HCC development and progression.

[Alteration of interferon-gamma and interleukin-12 released by bronchoalveolar lavage cells from pulmonary tuberculosis]

OBJECTIVE

To explore the change of cytokine released in bronchoalveolar lavage fluid (BALF) cells from pulmonary tuberculosis (TB) patients.

METHODS

BALF cells were obtained from group A: 10 normal control volunteers (normal control group); group B: 10 radiographically uninvolved sites of pulmonary TB patients (uninvolved sites group); group C: radiographically involved two lobes of lung and smear-positive of 10 pulmonary TB patients with an onset less than one year; and group D: radiographically involved more than three lobes and smear-positive of 10 pulmonary TB patients with an onset longer than two years. The IFN-gamma and IL-4 production in the culture supermate of BALF lymphocytes stimulated with PHA and IL-12 production in the culture supermate of BALF macrophage (AM) stimulated with lipopolysaccharide were determined using sandwich ELISA.

RESULTS

In group C, the IFN-gamma and IL-12 levels [(834 +/- 101) and (294 +/- 73) ng/L, respectively] were not only significantly higher than those of the group B[(197 +/- 59) and (67 +/- 23) ng/L, respectively, all P < 0.01] and normal control group[(179 +/- 51) and (57 +/- 24) ng/L, respectively, all P < 0.01], but also significantly higher than those of group D[(431 +/- 169) and (121 +/- 63) ng/L, respectively, all P < 0.01]; in group D, the IFN-gamma and IL-12 levels were significantly higher than those of the group B and normal control group (all P < 0.01); there were no significant differences between the group C and normal control group (P > 0.05); no differences were seen in IL-4 level among the 4 study groups.

CONCLUSIONS

A TH1 type response occurs in involved sites of pulmonary TB patients and that may result from AM which as a regulator through production of IL-12, and the TH1 type response may affect presentation and outcome in pulmonary TB.

[Effects of nao yi-an granule on hemorheological indexes and RCD (erythrocyte deformability) in patients with hemorrhagic stroke]

The effects of Nao Yi-an granule(Chinese medicine group, CMG) and western medicine (western medicine group, WMG) on hemorheological indexes and red cell deformability(RCD) were investigated in 40 patients with hemorrhagic stroke. The results showed that whole blood relative viscosity(high and low shear), whole blood reduced viscosity(high shear), plasma relative viscosity and RCD were significantly elevated before the treatment in both group than those of the control group(P < 0.01). After the treatment, the above indexes were lower in CMG than before the treatment and also lower in CMG than in WMG(P < 0.01). It is indicated that the Nao Yi-an granule is obviously superior to western medicine on the decrease of blood viscosity, increase of RCD, improvement of blood perfusion of brain tissue, protection of brain tissue and improved clinical in patients with hemorrhagic stroke.

Detection of hemochromatosis through the analysis of single- nucleotide extension products by capillary electrophoresis

Hereditary hemochromatosis is one of the most common hereditary disorders in Caucasians.The disease is linked to two single-nucleotide polymorphisms (SNPs) in the HFE gene.The two point mutations result in a change of Cys to Tyr at position 282 and His to Asp at position 63 in the resultant protein.We have developed a single-nucleotide extension (SNE) assay for hereditary hemochromatosis genetic testing, which employs capillary electrophoresis to simultaneously detect the SNE products generated from the two SNP sites. An upstream or a downstream primer adjacent to the possible mutation site is designed and extended one nucleotide further at the 3' end, complementary to the nucleotide at the possible mutation site.The extended nucleotide is one of four fluorescently labeled dideoxynucleotide triphosphates that also act as terminators. Analysis of the extended products by laser-induced fluorescence capillary electrophoresis (LIF-CE) directly reflects the identity of the possible mutation site. Using one primer upstream or downstream from the possible mutation site, three genotypes at one mutation site can be distinguished. Using both upstream and downstream primers provides a second level of specificity and increases the accuracy of the genetic test. The protocol can also be applied to the study of other SNP analyses and to simultaneous detection of multiple mutation sites.

A mutant herpes simplex virus type 1 thymidine kinase reporter gene shows improved sensitivity for imaging reporter gene expression with positron emission tomography

We are developing assays for noninvasive, quantitative imaging of reporter genes with positron emission tomography (PET), for application both in animal models and in human gene therapy. We report here a method to improve the detection of lower levels of PET reporter gene expression by utilizing a mutant herpes simplex virus type 1 thymidine kinase (HSV1-sr39tk) as a PET reporter gene. The HSV1-sr39tk mutant was identified from a library of site-directed mutants. Accumulation (net uptake) of the radioactively labeled substrates [8-(3)H]penciclovir ([8-(3)H]PCV), and 8-[(18)F]fluoropenciclovir (FPCV) in C6 rat glioma cells expressing HSV1-sr39tk is increased by a factor of approximately 2.0 when compared with C6 cells expressing wild-type HSV1-tk. The increased imaging sensitivity of HSV1-sr39tk when FPCV is used is also demonstrated in vivo both with tumor cells stably transfected with either HSV1-tk or HSV1-sr39tk, and after hepatic delivery of HSV1-tk or HSV1-sr39tk by using adenoviral vectors. The use of HSV1-sr39tk as a PET reporter gene and FPCV as a PET reporter probe results in significantly enhanced sensitivity for imaging reporter gene expression in vivo.

A multiscale dynamic programming procedure for boundary detection in ultrasonic artery images

Ultrasonic measurements of human carotid and femoral artery walls are conventionally obtained by manually tracing interfaces between tissue layers. The drawbacks of this method are the interobserver variability and inefficiency. In this paper, we present a new automated method which reduces these problems. By applying a multiscale dynamic programming (DP) algorithm, approximate vessel wall positions are first estimated in a coarse-scale image, which then guide the detection of the boundaries in a fine-scale image. In both cases, DP is used for finding a global optimum for a cost function. The cost function is a weighted sum of terms, in fuzzy expression forms, representing image features and geometrical characteristics of the vessel interfaces. The weights are adjusted by a training procedure using human expert tracings. Operator interventions, if needed, also take effect under the framework of global optimality. This reduces the amount of human intervention and, hence, variability due to subjectiveness. By incorporating human knowledge and experience, the algorithm becomes more robust. A thorough evaluation of the method in the clinical environment shows that interobserver variability is evidently decreased and so is the overall analysis time. We conclude that the automated procedure can replace the manual procedure and leads to an improved performance.

A transgenic model of acetaldehyde overproduction accelerates alcohol cardiomyopathy

Chronic alcohol consumption produces alcoholic heart muscle disease (AHMD), a prevalent form of congestive heart failure. Several hypotheses have been proposed to explain the damaging effects of alcohol on the heart, but neither the mechanism nor the ultimate toxin has been established. In this study, we use transgenic overexpression of alcohol dehydrogenase to elevate cardiac exposure to acetaldehyde, the major and most reactive metabolite of alcohol. Overexpression of alcohol dehydrogenase by 40-fold produced no detectable deleterious effects to the heart in the absence of alcohol. In the presence of alcohol, transgenic hearts contained 4-fold higher acetaldehyde than control hearts. Chronic alcohol exposure produced many changes similar to AHMD in transgenic hearts. Compared with control hearts, these pathological changes occurred more rapidly and to a greater extent: alcohol-exposed transgenic hearts were almost twice as large as control hearts. They demonstrated ultrastructural damage consistent with AHMD and had much lower contractility than alcohol-exposed control hearts. In addition, the transgenic hearts showed greater changes in mRNA expression for alpha-skeletal actin and atrial natriuretic factor than alcohol-exposed control hearts. Alterations in NAD(+)/NADH levels were insufficient to account for such severe damage in cardiomyopathic hearts. The increased damage produced in transgenic hearts suggests an important role for acetaldehyde in AHMD.

Lacrimal gland HGF, KGF, and EGF mRNA levels increase after corneal epithelial wounding

PURPOSE

To evaluate the effect of corneal epithelial wounding on lacrimal gland expression of hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), and epidermal growth factor (EGF) in the rabbit model.

METHODS

Rabbits had corneal epithelial scrape injuries, and the lacrimal gland was removed at different times after wounding. HGF, KGF, and EGF mRNA expression was examined by quantitative RNase protection assay. HGF, KGF, and EGF proteins were detected in rabbit lacrimal tissue using immunoprecipitation and western blot analysis.

RESULTS

HGF mRNA and EGF mRNA were significantly increased in rabbit lacrimal gland tissue within 8 hours after corneal epithelial injury. The increase in KGF mRNA expression was small and reached significance I clay after corneal injury. Lacrimal gland expression peaked at 3 days after wounding for each growth factor mRNA, the same day, on average, that the epithelial defect healed. After the peak increase in expression, there was a progressive decline in expression of each growth factor mRNA, but production was still increased compared with prewound levels. HGF protein, KGF protein, and EGF proteins were detected in rabbit lacrimal gland tissue.

CONCLUSIONS

Levels of HGF, KGF, and EGF mRNAs increase in rabbit lacrimal gland tissue in response to corneal epithelial wounding. The results of this study are consistent with the existence of a cornea-nervous system-lacrimal gland regulatory loop modulating expression of these growth factor mRNAs. The lacrimal gland is a likely source of increased HGF and EGF proteins detected in tears in previous studies.

Expression of HGF, KGF, EGF and receptor messenger RNAs following corneal epithelial wounding

Hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), epidermal growth factor (EGF), and their receptors have been associated with homeostasis and wound healing in the cornea. The purpose of this study was to examine the expression of the messenger RNAs for these growth factors and receptors in a wounded series of mouse corneas using in situ hybridization. In situ hybridization was performed with 3H-labeled riboprobes on unwounded corneas and corneas at 30 minutes, 4, 12, 24, 48 and 72 hr, and 7 days after epithelial scrape wounds in Balb/C mice. Qualitative and semi-quantitative analyses were performed. Expression of HGF, KGF and EGF mRNAs in keratocytes in the unwounded cornea was low. EGF mRNA was also expressed in unwounded corneal epithelium. Following wounding, however, these growth factor mRNAs were markedly upregulated in keratocytes. EGF mRNA expression in the epithelium appeared unaffected by wounding. At seven days after wounding and several days following closure of the epithelial defect, HGF mRNA and KGF mRNA were still expressed at higher levels in keratocytes compared with unwounded corneas. No difference in expression of HGF or KGF mRNAs between limbal, peripheral corneal, or central corneal keratocytes was noted in the unwounded cornea, KGF receptor mRNA was prominently expressed throughout the unwounded corneal epithelium. HGF receptor mRNA and EGF receptor mRNAs were expressed at low levels in unwounded cornea epithelium. Following scrape injury, expression of HGF receptor mRNA and KGF receptor mRNA were markedly upregulated in the corneal epithelium, while no significant increase in EGF receptor mRNA expression was noted. These studies suggest a prominent role for HGF and KGF in modulating corneal epithelial wound healing following injury. Less prominent changes in EGF mRNA and EGF receptor mRNA in the corneal epithelium following wounding may suggest that EGF has more of a role in homeostasis in the mouse corneal epithelium.

The relationship between caries activity and the status of dental caries--application of the Dentocult SM method

OBJECTIVE

To study the relationship between caries activity and the status of dental caries in preschool children using a caries activity test (CAT).

MATERIALS AND METHODS

The status of primary tooth caries in 229 children ages 3 to 5 was examined. Caries incidence, DFT, and caries severity index (CSI) were calculated. Based on the quantity of Streptococcus mutans in the oral cavity detected with Dentocult SM, a caries activity test, four grades of caries activity were classified: Grade 0 (< 10(4) colony-forming units/mL), Grade I (10(4)-10(5) CFU/mL), Grade II (10(5)-10(6) CFU/mL), and Grade III (> 10(6) CFU/mL).

RESULTS

The results showed that 79.48% children had Grade I or higher caries severity. Significant differences of caries activity were found among different grades, which were highly correlated with caries incidence, DFT, and CSI (r = 0.22216, 0.31212, and 0.32276, respectively).

CONCLUSIONS

As a CAT, Dentocult SM is a reliable method for measuring the status of dental caries in preschool children. It is also a valuable tool in the prevention and treatment of dental caries.

Signaling by HGF and KGF in corneal epithelial cells: Ras/MAP kinase and Jak-STAT pathways

PURPOSE

To characterize the signaling pathways used by hepatocyte growth factor (HGF) and keratinocyte growth factor (KGF) in human corneal epithelial cells.

METHODS

Cultures of SV40 large T antigen-transfected human corneal epithelial cells were treated with recombinant human HGF or KGF at 50 ng/ml to 100 ng/ml for 5 to 30 minutes and harvested for protein isolation. Immunoprecipitation was performed with antisera to signal transducers and activators of transcription 1 (STAT1), STAT3, Janus kinase 1 (Jak1), Shc, Grb2, Sos1, and HGF receptor (met). Immunoprecipitated proteins were analyzed by western blot analysis. Gel retardation experiments were carried out with first-passage human corneal epithelial cells to detect binding of STATs to the high affinity c-sis (platelet-derived growth factor) inducible DNA element (hSIE). Effects of HGF, KGF, and kinase inhibitors on mitogen-activated protein kinase (MAPK) activation were evaluated by western blot analysis and enzymatic assays.

RESULTS

In human corneal epithelial cells, the phosphorylation of adapter protein Shc (52- and 66-kDa isoforms) was enhanced by HGF, but not by KGF. Phosphorylated HGF receptor coimmunoprecipitated with Shc, Grb2, and Sos1. Hepatocyte growth factor or KGF rapidly activated MAPK in corneal epithelial cells. The activation of MAPK (p42 and p44) by HGF or KGF was transient and decreased gradually within 1 hour. MAPK kinase 1 (MEK1) inhibitor PD098059 or the protein tyrosine kinase inhibitor genistein blocked MAPK activation. Activation of MAPK induced by HGF was partially inhibited by protein kinase C inhibitor calphostin C. Hepatocyte growth factor and KGF had no effect on the activation of Jak-STAT cascade components that are activated by epidermal growth factor.

CONCLUSIONS

Hepatocyte growth factor and KGF activate Ras-MAPK pathways in human corneal epithelial cells. There may be at least two routes used by HGF in transmitting signals from its receptor to the MAPK cascade. One is the receptor-Grb2/Sos complex to the Ras pathway, and the other is through protein kinase C. Hepatocyte growth factor and KGF did not activate the Jak-STAT cascade components STAT1, STAT3, or Jak1 in corneal epithelial cells.

In vivo roles of Bm3R1 repressor in the barbiturate-mediated induction of the cytochrome P450 genes (P450(BM-3) and P450(BM-)1) of Bacillus megaterium

We previously showed [Q. Liang, A.J. Fulco, J. Biol. Chem., 270 (1995) 18606-18614) that the binding of Bm3R1 repressor to Barbie box elements and operator sites in the 5'-flanking regions of the P450BM-3 and P450BM-1 (CYP102 and CYP106) genes in Bacillus megaterium was a critical factor in their regulation at the level of transcription. We now describe experiments that delineate specific roles for Bm3R1 in the barbiturate-mediated induction of these genes. We directly demonstrate the interaction of Bm3R1 with Barbie box and operator sequences and show that high in vivo levels of Bm3R1 prevent putative positive factors from binding to Barbie box elements, strongly inhibit the expression of the P450 genes, prolong the lag phase of growth in Bacillus megaterium cultures and increase the sensitivity of the cells to the growth-inhibitory effects of barbiturates. Finally, our data suggest that there may be two forms of Bm3R1, either of which can interact with OIII, the bicistronic operator sequence.

Effects of perindopril on vascular wall and left ventricular hypertrophy in rats with experimental hypertension

The model of hypertensive rat was established by using the method of abdominal aortic constriction, 33 male SD rats were randomly divided into 4 groups: group A (sham-operated rats serving as controls), group B (hypertensive rats serving as controls), group C (hypertensive rats subjected to low-dose perindopril treatment, 0.1 mg.kg-1/d) and group D (hypertensive rats receiving high-dose perindopril treatment, 1.5 mg.kg-1/d). The drug was administered by gavage for 4 weeks. At the end of the treatment, mean arterious pressure (MAP) was measured via catheter in the carotid artery. The heart was taken and weighed to calculate the ratio of left ventricular weight to body weight (LVW/BW). The ratio of medial mean thickness to mean diameter of lumen of aorta and superior mesenteric artery was calculated by morphometry. Concentration of angiotensin II (A II) in plasma and in aortic wall were determined by radioimmunoassay (PA II, AA II). Our results showed that both high-dose and low-dose perindopril may prevent hypertrophy of left ventricle and hypertrophy of the tunica media of superior mesenteric artery. In addition, high-dose perindopril may significantly inhibit hypertrophy of aortic media. The above effects of perindopril may be explained by inhibition on tissue renin-angiotensin system of both vascular wall and heart, but is not related to circulating A II (PA II).

A new automated computerized analyzing system simplifies readings and reduces the variability in ultrasound measurement of intima-media thickness

BACKGROUND AND PURPOSE

A computerized analyzing system with manual tracing of echo interfaces for measurement of intima-media thickness and lumen diameter in carotid and femoral arteries was previously developed by our research group and has been used for many years in several laboratories. However, manual measurements are not only time consuming, but the results from these readings are also dependent on training and subjective judgement. A further problem is the observed drift in measurements over time. A new computerized technique for automatic detection of echo interfaces was therefore developed. The aim of this study was to evaluate the new automated computerized analyzing system.

METHODS

The new system is based on dynamic programming and includes optional interactive modification by the human operator. Local measurements of vessel echo intensity, intensity gradient, and boundary continuity are extracted by image analysis techniques and included as weighed terms in a cost function. The dynamic programming procedure is used for determining the optimal location of the vessel interfaces in a way that the cost function is minimized.

RESULTS

With the new automated computerized analyzing system the measurement results were less dependent on the reader's experience, and the variability between readers was less compared with the old manual analyzing system. The measurements were also less time consuming.

CONCLUSIONS

The new automated analyzing system will not only greatly increase the speed of measurements but also reduce the variability between readers. It should also reduce the variability between different laboratories if the same analyzing program is used. Furthermore, the new system will probably prevent the problem with drift in measurements over time.