Recognition and binding of the human selenocysteine insertion sequence by nucleolin

Prokaryotic and eukaryotic cells cotranslationally incorporate the unusual amino acid selenocysteine at a UGA codon, which conventionally serves as a termination signal. Translation of selenoprotein gene transcripts in eukaryotes depends upon a "selenocysteine insertion sequence" in the 3'-untranslated region. We have previously shown that DNA-binding protein B specifically binds this sequence element. We now report the identification of nucleolin as a partner in the selenoprotein translation complex. In RNA electromobility shift assays, nucleolin binds the selenocysteine insertion sequence from the human cellular glutathione peroxidase gene, competes with binding activity from COS cells, and shows diminished affinity for probes with mutations in functionally important, conserved sequence elements. Antibody to nucleolin interferes with the gel shift activity of COS cell extract. Antibody to DNA-binding protein B co-extracts nucleolin from HeLa cell cytosol, and the two proteins co-sediment in glycerol gradient fractions of ribosomal high salt extracts. Thus, nucleolin appears to join DNA-binding protein B and possibly other partners to form a large complex that links the selenocysteine insertion sequence in the 3'-untranslated region to other elements in the coding region and ribosome to translate the UGA "stop" codon as selenocysteine.

Oxidative stress disrupts glucocorticoid hormone-dependent transcription of the amiloride-sensitive epithelial sodium channel alpha-subunit in lung epithelial cells through ERK-dependent and thioredoxin-sensitive pathways

The amiloride-sensitive epithelial Na(+) channel (ENaC) plays a critical role in the maintenance of alveolar fluid balance. It is generally accepted that reactive oxygen and nitrogen species can inhibit ENaC activity and aggravate acute lung injury; however, the molecular mechanism for free radical-mediated ENaC inhibition is unclear. Previously, we showed that the expression of the alpha-subunit of ENaC, alpha-ENaC, which is indispensable for ENaC activity, is repressed by Ras activation in salivary epithelial cells. Here, we investigated whether exogenous H(2)O(2) modulates alpha-ENaC gene expression in lung epithelial cells through a similar molecular mechanism. Utilizing transient transfection reporter assays and site-directed mutagenesis analyses, we found that the glucocorticoid response element (GRE), located at -1334 to -1306 base pairs of the alpha-ENaC 5'-flanking region, is the major enhancer for the stimulated alpha-ENaC expression in A549 lung epithelial cells. We further demonstrate that the presence of an intact GRE is necessary and sufficient for oxidants to repress alpha-ENaC expression. Consistent with our hypothesis, exogenous H(2)O(2)-mediated repression of alpha-ENaC GRE activity is partially blocked by either a specific inhibitor for extracellular signal-regulated kinase (ERK) pathway activation, U0126, or dominant negative ERK, suggesting that, in part, activated ERK may mediate the repressive effects of H(2)O(2) on alpha-ENaC expression. In addition, overexpression of thioredoxin restored glucocorticoid receptor action on the alpha-ENaC GRE in the presence of exogenous H(2)O(2). Taken together, we hypothesize that oxidative stress impairs Na(+) transport activity by inhibiting dexamethasone-dependent alpha-ENaC GRE activation via both ERK-dependent and thioredoxin-sensitive pathways. These results suggest a putative mechanism whereby cellular redox potentials modulate the glucocorticoid receptor/dexamethasone effect on alpha-ENaC expression in lung and other tight epithelia.

Multiwatt High-Repetition-Rate 2-microm Output from an Intracavity KTiOPO(4) Optical Parametric Oscillator

We have obtained 6.5 W of 2-mum output from a near-degenerate, type II KTiOPO(4) (KTP) optical parametric oscillator (OPO) pumped within the cavity of a Q-switched diode-pumped Nd:YAG laser that operates at 3 kHz. We adopted the simplest configuration with a compact diode-pumped Nd:YAG module pumping the doubly resonant KTP OPO in its randomly polarized resonator with an acousto-optic Q switch. Attempts to increase the 2-mum output power by pumping this intracavity KTP OPO with a polarized laser beam by use of thermal birefringence compensation configurations are discussed.

[Reconstruction of anus in low rectum cancer operation]

OBJECTIVE

While low rectum cancer being resected with Mile's operation, the anus was reconstructed in situ simultaneously.

METHODS

Thirty cases of artificial anus were perfectly reconstructed in situ with transferring of the gracilis and invaginating of the end of the sigmoid for the outer and inner sphincter of the anus. The artificial rectum valve was used for the rectum angle.

RESULTS

The rate of excellent and good operative results reached 90.63%.

CONCLUSION

The results show that this method is suitable for radical operation of low rectum cancer and functional incapacitation of the anus from other diseases as well.

Distinct roles for amino- and carboxyl-terminal sequences of SPRR1 protein in the formation of cross-linked envelopes of conducting airway epithelial cells

The small proline-rich protein, SPRR1, is a marker gene whose expression in conducting airway epithelium is elevated under a variety of conditions that enhance squamous differentiation. The purpose of this study is to elucidate the nature of the SPRR1 sequence involved in cross-linked envelope formation in a tissue/cell type, such as conducting airway epithelium, that normally does not express squamous function except after injury or maintenance in culture. For this, a Flag-SPRR1 fusion protein expression system has been developed. Using the liposome-mediated gene transfer technique on passage 1 culture of human tracheobronchial epithelial (TBE) cells, the Flag-SPRR1 fusion protein can be expressed and detected immunologically by both anti-Flag and anti-SPRR1 antibodies. The incorporation of Flag-SPRR1 fusion protein into cross-linked envelopes can be demonstrated when transfected human passage 1 TBE cultures are treated with phorbol 12-myristate 13-acetate and high calcium (1.5 mM). By deletion and site-directed mutagenesis, two distinct roles of the amino- and carboxyl-terminal sequences of SPRR1 have been demonstrated. First, we demonstrated that the amino-terminal sequence of SPRR1 protein is required for the incorporation of the fusion protein into cross-linked envelopes, whereas a deletion on the carboxyl-terminal region or on the middle repetitive unit has no effect. Interestingly, insertion of a 24-amino acid peptide of monkey MUC2 repetitive sequence in the amino-terminus of SPRR1 protein had a stimulatory effect. Site-directed mutagenesis on the following amino acid residues, Lys(7), Gln(88), and Lys(89), which were found previously to participate in the cross-linked envelope formation of keratinocytes, had no detrimental effect on the incorporation. However, mutations on Gln clusters, such as Gln(4)-Gln(6) and Gln(22)-Gln(25), had detrimental effects on the incorporation. These results suggest an amino-terminal sequence-dependent and multiple cross-linked sites for the incorporation of Flag-SPRR1 fusion protein into cross-linked envelopes of cultured human TBE cells. Second, we demonstrated that the carboxyl terminus of SPRR1 protein is required for a high level of Flag-fusion protein expression. A deletion in the carboxyl region or a mutation on the last lysine residue of the carboxyl end had a detrimental effect on the level of Flag-SPRR1 fusion protein expressed in transfected cells. In contrast, there was only a slight decrease in the level of expression if the amino-terminus was deleted. Interestingly, the efficiency for fusion protein to incorporate into cross-linked envelopes was elevated by the mutation at the carboxyl end. These results suggest distinct roles, perhaps coordinately, for both amino- and carboxyl-terminal sequences in the regulation of the life cycle of SPRR1 protein in cultured TBE cells.

Restored expression of fragile histidine triad protein and tumorigenicity of cervical carcinoma cells

BACKGROUND

Allelic losses in the short arm of chromosome 3 are common in cervical carcinomas. The fragile histidine triad (FHIT) gene at chromosome region 3p14.2 is a candidate tumor suppressor gene that may play a role in cervical tumorigenesis. We and others have identified aberrant FHIT transcripts and frequent loss of Fhit protein expression in primary cervical cancers and high-grade noninvasive lesions but not in normal cervical tissues. The altered expression of FHIT may be due to somatic mutations or integration of human papillomavirus DNA at the FHIT locus. The purpose of this study was to determine whether ectopic expression of Fhit can suppress the tumorigenic properties of cervical cancer cells.

METHODS

We employed infection with recombinant retroviruses as well as transfection of plasmid DNA to restore Fhit protein expression in cervical cancer cell lines lacking full-length FHIT transcripts and endogenous Fhit protein. The effects of Fhit expression on tumor cell morphology, anchorage-independent growth, and tumorigenicity in nude mice were examined.

RESULTS

Stable overexpression of Fhit had no discernible effect on the tumorigenic properties of two cervical carcinoma cell lines or on a lung carcinoma cell line previously reported by others to be suppressed for tumorigenicity by Fhit.

CONCLUSIONS

Restoration of Fhit expression does not suppress anchorage-independent growth or tumorigenicity of cervical carcinoma cell lines. However, it remains possible that FHIT inactivation may be important early in cervical tumor progression or that FHIT may suppress tumorigenesis in ways distinct from those measured by the assays employed in this study.

Vibrational coupling in oxo-centred trinuclear clusters: oxygen-16/18 isotopic substitution studies of [Fe3III(O)(O2CC(CH3)3)6(py)3][FeCl4] and [Fe2(III)FeII(O)(O2CC(CH3)3)6(py)3]

IR spectra are reported for the compounds [Fe3O(O2CC(CH3)3)6(py)3][FeCl4] and [Fe3O(O2CC(CH3)3)6(py)3]. Using isotopic substitution at the central oxygen atom, the assignments of the in-plane and out-of-plane vibrations of this atom are confirmed, and coupling is demonstrated between the in-plane modes v(as)(Fe3O) and carboxylate deformation modes rho(r)(C-CO2).

Cochlear findings in the white spotting (Ws) rat

White spotting (Ws) rats possess a c-kit gene mutation at the W locus, resulting in a variety of characteristics including a lack of intermediate cells of the stria vascularis. The present study employs a light microscope (LM), scanning (SEM) and transmission electron microscopes (TEM), diaminobenzidine (DAB) staining techniques and auditory brainstem response (ABR) to investigate the structure and function of the cochlea in 26 homozygous Ws/Ws rats aged 1-6 months. A slight thinning of the stria vascularis and moderate elevation of ABR threshold were about the only defects noted in 1 month animals, while older animals displayed various defects that tended to worsen with age. At 3 months LM revealed pigment granules in the basal turn of most animals, with a loss of pigmentation in the upper turns. The stria vascularis and organ of Corti tended to be well preserved in the lower, pigmented portion, while the upper, unpigmented portion showed severe strial degeneration and some outer hair cell loss. DAB staining revealed a well developed strial capillary net throughout the pigmented portion of the cochlea, with severe degradation in the unpigmented apical portion. ABR thresholds were slightly elevated over 1 month values. At 6 months great differences in degeneration were noted between right and left ears of the same animal.

[Study on the physicochemical properties of Campylobacter jejuni enterotoxin]

Precipitate of Campylobacter jejuni cytotonic enterotoxin(CE) performed in an 80% saturated solution of ammonium sulfateit indicated that there were some little molecular proteins except the 68 kD main band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE), whereas the eluate from GM1 ganglioside affinity column chromatography exhibited only one 68 kD band on SDS-PAGE. The results suggest that CE mainly be consisted of 68 kD protein. The toxin is heat-labile, pH dependent and resistant to trypsin, It could be completely inactivated by heating at either 56 degrees C and 60 degrees C for 30 min or 100 degrees C for 15 min. The activity was maximum at pH 6.0 and was completely inactivate at pH 3.0 and pH 9.0, and rapidly reduced after storage over 3 d at 4 degrees C. The anti-LT serum could completely inhibited the activity of CE.

Linearly polarized 100-W output from a diode-pumped Nd:YAlO laser

We demonstrate a compact cw diode-pumped Nd:YAlO laser that can produce 100 W of power at 1079 nm and 18.3 W at 1341 nm. Lasing and nonlasing thermal lensing data are presented.

Expression and regulation of a molecular marker, SPR1, in multistep bronchial carcinogenesis

A small proline-rich protein, SPR1, is overexpressed in squamous metaplasia of bronchial epithelium. We studied the expression and regulation of SPR1 in a series of human bronchial epithelial cell lines representing a model of multistep bronchial carcinogenesis. These cell lines included a primary culture of tracheobronchial epithelial cells (HTBE), a papilloma virus-transformed tracheobronchial epithelial cell line (HBE1), a cell line selected from HBE1 by a tobacco carcinogen and a phorbol ester (HBE1-C), a simian virus-transformed bronchial epithelial cell line (BEAS-2B), and a lung carcinoma cell line (H460). Different tumorigenic potentials of these cell lines were indicated by graded levels of telomerase activity. Concomitant with squamous transformation, there was an increase in SPR1 expression in HTBE, HBE1, and HBE1-C that was reversible by vitamin A. With progression of tumorigenicity, there was a marked reduction in SPR1 expression in BEAS-2B and a total loss of expression in H460. In these latter cell lines representing advanced malignant transformation, there was a loss of up- and downregulation, respectively, by the phorbol ester and vitamin A. Transfection study with chimeric constructs of the SPR1 promoter and a reporter gene showed that the dysregulation of SPR1 expression in malignant transformation was a result of perturbation of the basal and enhancer elements of the first 162 nucleotides in the 5'-flanking promoter region of the SPR1 gene. These findings suggest an association of transcriptional dysregulation of the SPR1 gene with multistep bronchial carcinogenesis.

Effects of cigarette smoke extract on E-cadherin expression in cultured airway epithelial cells

To investigate whether the change of E-cadherin (ECD) expression plays a role in the injury and repair of airway epithelial cells (AEC) caused by smoking, porcine AECs were cultured by using an enzyme-dispersed method. After exposure of the AECs to cigarette smoke extract (CSE), the ECD expression in the cells was detected by using immunocytochemistry and in situ hybridization. The results showed that ECD was distributed on the plasma membrane at the cell junctions of AECs. After exposure to 20% CSE, the membranous ECD expression was decreased, the cytoplasmic ECD expression was increased (P < 0.01) as the exposure time went on. But the content of ECD mRNA in the AECs did not chang. It suggests that the change of ECD expression is regulated at the posttranslational level and plays a role in the injury and repair of AEC caused by smoking.

[Lutembacher's syndrome]

OBJECTIVE

To compare classical and acquired Lutembacher's syndrome (mitral restenosis after percutaneous balloon mitral valvuloplasty) in attempt to know their different in pathophysiology, diagnosis, and surgical treatment.

METHODS

The data from 22 cases of classical and acquired Lutembacher's syndrome who underwent surgical treatment in the same period were analyzed.

RESULTS

No death occurred in the classical group. In the acquired group the mortality however was 42.8% for those highly complicated with pulmonary hypertension and right heart failure.

CONCLUSIONS

Classical Lutembacher's syndrome can be corrected satisfactorily. The acquired one deteriorates rapidly with severe pulmonary hypertension and right heart failure, and needs early surgical intervention reduce the operation mortality.

Germline mutations in NF1 patients with malignancies

We have analyzed 98.5% of the coding region of the NF1 gene at the cDNA level in seven NF1 patients who developed malignant peripheral nerve sheath tumors. Seven germline mutations were detected in six individuals: a 6-bp in-frame deletion in exon 28, a splice acceptor mutation in intron 31 resulting in a premature stop of translation, a missense mutation in exon 38, and three total NF1 gene deletions. In one of the patients with a total NF1 gene deletion, a missense mutation in exon 16 on the other NF1 allele was detected. These data indicate that NF1 patients developing malignant neoplasms can have any type of NF1 germline mutation such as a total gene deletion, a frameshift mutation, an in-frame deletion, or a missense mutation. We conclude that in our series no specific type of NF1 germline mutation was found in NF1 individuals with malignancies, but that large NF1 gene deletions were more frequently found in this group than reported for the general population of NF1 individuals. Genes Chromosomes Cancer 26:376-380, 1999.

[In vitro adherence of bacteria to intraocular lenses of different materials]

OBJECTIVE

To compare the in vitro adherence of different bacteria onto the surface of various intraocular lenses (IOLs).

METHOD

Electron microscopic and bacterial culture quantitative methods were used to study the adherence of Staphylococcus (S) epidermidis, Staphylococcus aureus and Pseudomonas (P) aeruginosa onto the surface of PMMA and other three foldable IOL materials (HEMA, ACRY, SI).

RESULTS

S. Epidermidis: HEMA < ACRY < SI < PMMA; S. aureus: HEMA was the least and PMMA was the most, no significant difference between ACRY and SI IOLs; P. aeruginosa: HEMA was the least while no significant difference among PMMA, SI and ACRY IOLs (P > 0.05).

CONCLUSION

The foldable IOLs have the potent ability to reduce the infectious endophthalmitis after surgery of extraction of cataract with IOL implantation.

[Effect of bFGF, IGF-I and their synergy on the mitogenesis of bovine lens epithelial cells]

OBJECTIVE

To assess the effect of basic fibroblast growth factor (bFGF), insulin like growth factor-I (IGF-I) and their synergy on the mitosis of bovine lens epithelial cells (BLECs).

METHODS

BLECs were cultured in vitro. The fourth passage cells were inoculated into 24 well tissue culture plates, treated with different concentrations of bFGF, IGF-I, and bFGF + 20 microg/L IGF-I for 20 hours, (3)H-thymidine was added for 16 hours, then the radioactivity was determined by liquid scintillation counting.

RESULTS

Either bFGF (1 - 100 microg/L) or IGF-I (20 - 100 microg/L) increases mitosis of BLEC significantly, and 20 microg/L IGF-I may increase bFGF induced mitogenesis.

CONCLUSION

Growth factor and their synergic effect may play an important role in lens epithelial cell proliferation.

[Effects of high fluoride intake on the fluoride of femora, teeth and some biochemical indexes in rats]

In order to approach practicable indexes for assessing the effects of the products which are intended to be used to prevent endemic fluorosis, Wistar rats were fed with fluoridated water(50 mg/L) for four weeks. After only one week treated with fluoride, a higher activity of NAG(N-acetyl-beta-D-glucosaminidase) in urine, ChE(cholinesterase) in blood and increased urinary excretion of fluoride (compared with the control, P < 0.01) were observed, and these changes were lasted to the end of the fourth week of the study, but hydroxyproline in serum and urine had not been changed in both groups. After four weeks, the fluoride levels in the femora and teeth of fluoride treated group were ten times higher than that of the control group. According to the results, fluoride in bones and teeth must be taken as key indexes, the activities of NAG in urine and ChE in blood should be taken into consideration for assessing the effects of fluoride protagonist.

Antibodies to platelet-activating factor are associated with borderline hypertension, early atherosclerosis and the metabolic syndrome

OBJECTIVE

Platelet-activating factor (PAF) is a phospholipid inflammatory mediator which is synthesized by a variety of cells, including monocytes and endothelial cells, and PAF can be retained in activated endothelial cell membranes. Furthermore, PAF-like lipids are produced in other phospholipid membranes as in oxidized LDL. Atherosclerosis is a chronic inflammation in the artery wall, but little is known about the role of immune reactions in the early stages of development of cardiovascular disease. In the present study we investigated if there are antibodies to PAF (aPAF) that may play a role in borderline hypertension and early atherosclerosis.

DESIGN

Seventy-three men with borderline hypertension (BHT) and 73 age-matched normotensive (NT) men (diastolic blood pressure 85-94 and <80 mmHg, respectively) were recruited from a population screening programme. Antibody levels were determined by use of ELISA. Carotid intima-media (IM)-thickness and atherosclerosis was determined by B-mode ultrasonography.

RESULTS

BHT men had 49.3% higher aPAF levels of IgG class than NT controls (P = 0.0007). Antibodies to the biologically inactive lysoPAF did not differ between BHT and NT group. aPAF levels were associated with IM-thickness in the left (P = 0.02) and right (P = 0.009) carotid artery. Furthermore, aPAF levels were enhanced in individuals with the metabolic syndrome (n = 44) as compared to those without (n = 102; P = 0.009), and also significantly associated with insulin levels (P = 0.02) and insulin resistance (P = 0.02).

CONCLUSIONS

aPAF antibodies may reflect early vascular changes and thus serve as novel markers for disease, and they may also be pathogenic, by eliciting an inflammatory reaction in the vascular wall.

Somatic mutations of the PPP2R1B candidate tumor suppressor gene at chromosome 11q23 are infrequent in ovarian carcinomas

Previous studies have demonstrated frequent allelic losses of distal chromosome 11q in ovarian carcinomas. The tumor suppressor gene(s) presumably targeted by these losses have not yet been identified. PPP2R1B is a candidate tumor suppressor gene at 11q23 that has recently been shown to be mutated in a subset of colorectal and lung cancers. We evaluated 5 ovarian carcinoma cell lines and 27 primary ovarian carcinomas for allelic losses of 11q23 and for mutations in the open reading frame of PPP2R1B. We also evaluated the primary tumors for allelic losses at 17p13, another chromosomal region frequently affected by losses of heterozygosity (LOH) in ovarian cancers. 11q23 and 17p13 allelic losses were identified in 25% and 74% of the carcinomas, respectively. No mutations within PPP2R1B coding sequences were found. These findings indicate that mutations of the PPP2R1B gene are infrequent in ovarian cancer and that deletions affecting the distal portion of chromosome 11q in ovarian cancer likely target inactivation of other genes.

Changes in off-lesion endocochlear potential following localized lesion in the lateral wall

Endocochlear potential (EP) was measured at various off-lesion sites after a small focal lesion was made in the lateral wall of the guinea pig cochlea. Lesions were produced by a photochemical reaction between systemically administered rose bengal and focused green light illumination. In 21 ears, continuous measurement for 30 min after onset of the reaction at turns apical or basal to the site of illumination revealed no significant changes in EP compared with the control value (p < 0.01). In another group of 43 ears, EP was measured at 3 days post-illumination. A significant decline was seen at every site located apical to the lesion (p < 0.001). Conversely, no significant change was measured at any site located basal to the lesion. These findings suggest that the decrease in EP assumes the form of a gradient from the lower to upper turns in the guinea pig cochlea.

Differential expression of stress proteins in nonhuman primate lung and conducting airway after ozone exposure

The presence of seven stress proteins including various heat shock proteins [27-kDa (HSP27), 60-kDa (HSP60), 70-kDa (HSP70) and its constitutive form HSC70, and 90-kDa (HSP90) HSPs] and two glucose-regulated proteins [75-kDa (GRP75) and 78-kDa (GRP78) GRPs] in ozone-exposed lungs of nonhuman primates and in cultured tracheobronchial epithelial cells was examined immunohistochemically by various monoclonal antibodies. Heat treatment (42 degrees C) resulted in increased HSP70, HSP60, and HSP27 and slightly increased HSC70 and GRP75 but no increase in GRP78 in primary cultures of monkey tracheobronchial epithelial cells. Ozone exposure did not elevate the expression of these HSPs and GRPs. All of these HSPs including HSP90, which was undetectable in vitro, were suppressed in vivo in monkey respiratory epithelial cells after ozone exposure. Both GRP75 and GRP78 were very low in control cells, and ozone exposure in vivo significantly elevated these proteins. These results suggest that the stress mechanism exerted on pulmonary epithelial cells by ozone is quite different from that induced by heat. Furthermore, differences between in vitro and in vivo with regard to activation of HSPs and GRPs suggest a secondary mechanism in vivo, perhaps related to inflammatory response after ozone exposure.

[Cardic death and apoptosis of myocardium]

TdT-mediated Dutp nick end labeling (TUNEL) method was applied to detect apoptosis of myocardium of corpses dying from cardiac death. For arteriosclerotic coronary heart death, diffused apoptosis was observed around the border zones of histologically infarcted myocardium, and in the epithelial and smooth muscle of arteries. Few apoptosis cells were present for hypertensive heart death, and none for corpses dying from falling and hanging. Myocardium apoptosis may provide a new target for heart failure.

Carotid bifurcation CT angiography: assessment of interactive volume rendering

PURPOSE

The purpose of this study was to compare the accuracy of CT angiography (CTA) for the assessment of carotid bifurcation stenosis, using interactive volume rendering (VR), maximum intensity projection (MIP), and 2D transverse CT technique (t-CT).

METHOD

Nineteen consecutive patients were prospectively studied with CTA and selective digital subtraction angiography (DSA). There were 13 men and 6 women from 51 to 84 years old (mean 70 years). Results of DSA were compared with those of interactive VR, MIP, and conventional t-CT results, using North American Symptomatic Carotid Endarterectomy Trial criteria for stenosis grading.

RESULTS

There were a total of 38 carotid bifurcations studied, with 9 mild, 10 moderate, and 15 severe stenoses and 4 occlusions. Overall agreement with DSA for VR was achieved in 76%. Eighty percent of the severe stenoses were correctly predicted by VR. The overall agreement between t-CT and DSA was 89%. MIP images, when analyzed independently, showed an overall agreement with angiography of only 71%. VR was not significantly different from MIP (p = 0.60). The difference between VR and t-CT had borderline significance (p = 0.09). MIP had significantly poorer agreement with angiography than t-CT (p = 0.02).

CONCLUSION

CTA has a high degree of accuracy for the assessment of carotid artery disease compared with catheter angiography. Interactive VR increases the accuracy of diagnosing carotid stenosis and decreases the number of unsatisfactory studies as compared with MIP. Further advances in computation speeds and improvements in software may dramatically alter the future use of VR for the communication of results to clinicians; however, careful analysis of transverse sections is essential to accurate CT interpretation.

[Effect of cigarette smoke extract on E-cadherin expression of airway epithelial cells]

OBJECTIVE

To explore the possible mechanism of injury by smoking, and the effect of cigarette smoke extract (CSE) on E-cadherin (ECD) expression in airway epithelial cells (AEC) was observed.

METHODS

Mouse trachea and pig AEC were cultured in vitro. After CSE exposure, the expression of ECD in AECs was evaluated using immunohistochemical stain and image analysis.

RESULTS

ECD was distributed on the plasma membrane at the cell junctions of AECs. At 12th and 24th hour after CSE exposure, the ECD expression on membrane decreased, whereas the cytoplasmic expression increased (P < 0.01) as compared with the normal controls. The expression at 24th hour was higher than that at 12th hour (P < 0.01).

CONCLUSIONS

CSE decreases the membranous expression of ECD in AECs, but increases the cytoplasmic expression. The change of ECD expression may mediate the airway epithelial injuries by smoking.

[The study of E-cadherin expression on injury and repair of epithelium of respiratory tract in smoking mice]

OBJECTIVE

To investigate effects of smoking on E-cadherin (E-cd) expression of injury and repair of respiratory tract epithelium by observation of dynamic expression of E-cd on epithelial cells of respiratory tract in smoking mice.

METHODS

Immunohistochemistry SP technique was used to examine E-cd expression on epithelial cells of respiratory tract in smoking mice of different stages and dosages and the morphological changes observed by light and electron microscopy respectively.

RESULTS

Four and twelve weeks after smoking, the E-cd expression in the epithelial cells was significantly down-regulated compared with the control group (P < 0.01). Morphologically, the intercellular junction was loose, and the epithelial cells were injured and proliferated on the same time. Eight weeks after smoking, however, the E-cd expression was not different from that of the control group (P > 0.05).

CONCLUSIONS

Smoking is able to cause wavy change of the E-cd expression on the epithelial cells which may play an important role in the injury and repair of the epithelial cell of the respiratory tract.