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Biomedical subjects

M Lu

Publications and source records attributed to M Lu.

At least 145 records · Page 8Linked to original sources

The Next Step Trial: impact of a worksite colorectal cancer screening promotion program.

BACKGROUND: The Next Step Trial was a randomized trial of worksite colorectal cancer screening promotion and nutrition interventions for automobile industry employees at increased risk of colorectal cancer. Interventions were tested at 28 worksites with 5,042 employees. This report describes results of the screening promotion intervention. METHODS: Worksites randomized to the control group received a standard program including rectal examination, fecal occult blood testing, and flexible sigmoidoscopy. Intervention worksites received an enhanced program (i.e., standard program plus an educational booklet/telephone call). Compliance (i.e., completion of all recommended screening examinations) and coverage (i.e., completion of at least one screening examination), the primary and secondary outcomes, were measured over 2 years. RESULTS: In the 2 years prior to baseline, 61% of employees had been screened. After random assignment, baseline differences in several employee characteristics and worksite screening procedures were detected, including more past history of screening in control worksites. After adjusting for differences, we found modest, but higher, compliance and coverage in intervention compared with control worksites (odds ratio [95% confidence limits] = 1.46 [1.1-2.0] and 1.33 [1.1, 1.6], respectively). CONCLUSIONS: Adding a personally tailored behavioral intervention to a standard colorectal cancer screening program can promote continued employee participation in screening as measured by compliance. Further research is needed to assess intervention effects in other populations.

Automobiles↗

Color Doppler energy and related quantitative analysis of gestational trophoblastic tumors.

OBJECTIVE: To assess the reliability of color Doppler energy (CDE) and a related quantitative analysis for detection and follow-up of uterine involvement in gestational trophoblastic tumor. METHOD: CDE was performed in 19 patients with trophoblastic tumor, in 25 women in early pregnancy and 25 non-pregnant women. The blood flow area ratio (BFAR) in CDE was used as an index representing uterine involvement. In nine of the 19 patients, BFAR was measured before, during and at termination of chemotherapy. RESULT: The BFAR (mean +/- S.D.) of uterine profiles in 19 patients (39.9 +/- 1.3%) was significantly higher than that in 25 pregnant women (24.6 +/- 10.1%, P = 0.002) and in 25 non-pregnant women (14.8 +/- 5.7%, P = 0.001). In the follow-up of nine patients, when beta-hCG was less than 3.1 ng/ml during the treatment, the BFAR (38.7 +/- 11.9%) decreased below that (44.2 +/- 14.6%) seen prior to treatment (P = 0.009) and was much lower at termination of treatment (27.5 +/- 12.3%, P = 0.048). CONCLUSION: These data support the use of CDE and the related quantitative analysis as a new method for detecting and follow-up of uterine involvement in patients with trophoblastic tumors.

Adult↗

Effect of arsenic trioxide on viability, proliferation, and apoptosis in human megakaryocytic leukemia cell lines.

Arsenic trioxide (As2O3) has been demonstrated to be effective for the treatment of acute promyelocytic leukemia (APL) and to inhibit proliferation and produce apoptosis in the APL cell line NB4. To determine if As2O3 might be useful for the treatment of other lineages, we investigated the effects of As2O3 on viability, proliferation, and induction of apoptosis in the megakaryocytic leukemia cell lines HEL, Meg-01, UT7, and M07e. Our results showed that As2O3, at concentrations of 0.1-2.0 microM, causes a dose- and time-dependent inhibition of survival and growth in all four megakaryocytic leukemia cell lines studied. In contrast, As2O3 at similar concentrations had no effects on either viability or growth of the nonmegakaryocytic leukemia cell line HL60 and two human breast cancer cell lines, ZR75 and MCF7. In situ end-labeling of DNA fragments (TUNEL assay) indicated that As2O3, at concentrations of 0.5-2 microM, could significantly induce apoptosis in the aforementioned four megakaryocytic leukemia cell lines, but not in the nonmegakaryocytic HL60, ZR75, and MCF7 cell lines. These results were confirmed using conventional morphologic assessment and the DNA ladder assay. Induction of apoptosis in arsenic-treated Meg-01 and UT7 cells was accompanied by a dose-response decrease of Bcl-2 protein, whereas As2O3 had no effect on this measurement in HL60, ZR75, and MCF7 cell lines. Pertinently, these concentrations of As2O3 produced identical changes in the characteristics of the APL cell line NB4. Collectively, these data demonstrate that As2O3 can selectively inhibit growth and induce apoptosis in megakaryocytic leukemia cell lines. The use of As2O3 for the treatment of malignant megakaryocytic disorders should be considered.

Apoptosis↗

Blockade of NAALADase: a novel neuroprotective strategy based on limiting glutamate and elevating NAAG.

Excessive glutamate receptor activation is thought to be involved in the neuronal injury caused by stroke. Based on the hypothesis that N-acetyl-aspartyl-glutamate (NAAG) is a modulatory neurotransmitter or storage form of glutamate, we have pursued a novel strategy of therapeutic intervention, blockade of N-acetylated alpha-linked acidic dipeptidase (NAALADase), the enzyme that hydrolyzes NAAG to liberate glutamate. Using the suture model of transient middle cerebral artery occlusion (MCAO) in rats, the prototype NAALADase inhibitor 2-(phosphonomethyl)pentanedioic acid (2-PMPA) dramatically reduced extracellular glutamate accumulation measured by microdialysis both during a 2-hour occlusion and during reperfusion, consistent with an effect on glutamate supply. During reperfusion, the decrease in glutamate was accompanied by an equimolar, reciprocal rise in extracellular NAAG. NAALADase inhibition may prove to be a well tolerated therapy for cerebral ischemia. In addition, NAALADase inhibitors should prove to be important tools in understanding the physiological role of NAAG in the brain.

Animals↗

Immunization of woodchucks with plasmids expressing woodchuck hepatitis virus (WHV) core antigen and surface antigen suppresses WHV infection.

DNA vaccination can induce humoral and cellular immune response to viral antigens and confer protection to virus infection. In woodchucks, we tested the protective efficacy of immune response to woodchuck hepatitis core antigen (WHcAg) and surface antigen (WHsAg) of woodchuck hepatitis virus (WHV) elicited by DNA-based vaccination. Plasmids pWHcIm and pWHsIm containing WHV c- or pre-s2/s genes expressed WHcAg and WHsAg in transient transfection assays. Pilot experiments in mice revealed that a single intramuscular injection of 100 microgram of plasmid pWHcIm DNA induced an anti-WHcAg titer over 1:300 that was enhanced by boost injections. However, two injections of 100 microgram of pWHcIm did not induce detectable anti-WHcAg in woodchucks. With an increase in the dose to 1 mg of pWHcIm per injection, transient anti-WHcAg response and WHcAg-specific proliferation of peripheral mononuclear blood cells (PMBCs) appeared in woodchucks after repeated immunizations. Four woodchucks vaccinated with pWHcIm were challenged with 10(4) or 10(5) of the WHV 50% infective dose. They remained negative for markers of WHV replication (WHV DNA and WHsAg) in peripheral blood and developed anti-WHs in week 5 after challenge. In contrast, woodchucks not immunized or immunized with the control vector pcDNA3 developed acute WHV infection. Two woodchucks immunized with 1 mg of pWHsIm developed WHsAg-specific proliferative response of PBMCs but no measurable anti-WHsAg response. A rapid anti-WHsAg response developed during week 2 after virus challenge. Neither woodchuck developed any signs of WHV infection. These data indicate that DNA-based vaccination with WHcAg and WHsAg can elicit immunity to WHV infection.

Amino Acid Sequence↗

Human cytomegalovirus UL69 protein induces cells to accumulate in G1 phase of the cell cycle.

Earlier studies have revealed that human cytomegalovirus rapidly inhibits the growth of fibroblasts, blocking cell cycle progression at multiple points, including the G1-to-S-phase transition. The present study demonstrates that the UL69 protein, a virus-encoded constituent of the virion, is able to arrest cell cycle progression when introduced into uninfected cells. Expression of the UL69 protein causes U2 OS cells and primary human fibroblasts to accumulate within the G1 compartment of the cell cycle, and serum fails to induce the progression of quiescent human fibroblasts into the S phase when the protein is present. Therefore, the UL69 protein is at least partially responsible for the cell cycle block that is instituted after infection of permissive cells with human cytomegalovirus.

Cytomegalovirus↗

Inhibition of human immunodeficiency virus type 1 infectivity by the gp41 core: role of a conserved hydrophobic cavity in membrane fusion.

The gp41 envelope protein of human immunodeficiency virus type 1 (HIV-1) contains an alpha-helical core structure responsible for mediating membrane fusion during viral entry. Recent studies suggest that a conserved hydrophobic cavity in the coiled coil of this core plays a distinctive structural role in maintaining the fusogenic conformation of the gp41 molecule. Here we investigated the importance of this cavity in determining the structure and biological activity of the gp41 core by using the N34(L6)C28 model. The high-resolution crystal structures of N34(L6)C28 of two HIV-1 gp41 fusion-defective mutants reveal that each mutant sequence is accommodated in the six-helix bundle structure by forming the cavity with different sets of atoms. Remarkably, the mutant N34(L6)C28 cores are highly effective inhibitors of HIV-1 infection, with 5- to 16-fold greater activity than the wild-type molecule. The enhanced inhibitory activity by fusion-defective mutations correlates with local structural perturbations close to the cavity that destabilize the six-helix bundle. Taken together, these results indicate that the conserved hydrophobic coiled-coil cavity in the gp41 core is critical for HIV-1 entry and its inhibition and provides a potential antiviral drug target.

Amino Acid Sequence↗

Subdomain folding and biological activity of the core structure from human immunodeficiency virus type 1 gp41: implications for viral membrane fusion.

The envelope glycoprotein of human immunodeficiency virus type 1 (HIV-1) consists of two subunits, gp120 and gp41. The extraviral portion (ectodomain) of gp41 contains an alpha-helical domain that likely represents the core of the fusion-active conformation of the molecule. Here we report the identification and characterization of a minimal, autonomous folding subdomain that retains key determinants in specifying the overall fold of the gp41 ectodomain core. This subdomain, designated N34(L6)C28, is formed by covalent attachment of peptides N-34 and C-28 by a short flexible linker in place of the normal disulfide-bonded loop sequence. N34(L6)C28 forms a highly thermostable, alpha-helical trimer. Point mutations within the envelope protein complex that abolish membrane fusion and HIV-1 infectivity also impede the formation of the N34(L6)C28 core. Moreover, N34(L6)C28 is capable of inhibiting HIV-1 envelope-mediated membrane fusion. Taken together, these results indicate that the N34(L6)C28 core plays a direct role in the membrane fusion step of HIV-1 infection and thus provides a molecular target for the development of antiviral pharmaceutical agents.

Amino Acid Sequence↗

Underlying structure of the National Institutes of Health Stroke Scale: results of a factor analysis. NINDS tPA Stroke Trial Investigators.

BACKGROUND AND PURPOSE: No stroke scale has been validated as an outcome measure using data from a clinical trial demonstrating a positive therapeutic effect. Therefore, we proposed to use data from the National Institute of Neurological Disorders and Stroke (NINDS) tPA Stroke Trial to determine whether the National Institutes of Health Stroke Scale (NIHSS) was valid in patients treated with tissue plasminogen activator (tPA) and to explore the underlying clinimetric structure of the NIHSS. METHODS: We performed an exploratory factor analysis of NIHSS data from Part 1 (n=291) of the NINDS tPA Stroke Trial to derive a hypothesized underlying factor structure. We then performed a confirmatory factor analysis of this structure using NIHSS data from Part 2 of the same trial (n=333). We then tested whether this final factor structure could be found in tPA- and placebo-treated patients serially over time after stroke treatment. Using 3-month outcome data, we tested for an association between the NIHSS and other measures of stroke outcome. RESULTS: The exploratory analysis suggested that there were 2 factors underlying the NIHSS, representing left and right brain function, confirming the content validity of the scale. An alternative structure composed of 4 factors could be derived, with a better goodness of fit: the first 2 factors could represent left brain cortical and motor function, respectively, and the second 2 factors could represent right brain cortical and motor function, respectively. The same factor structures were then found in tPA and placebo patient groups studied serially over time, confirming the exploratory analysis. All 3-month clinical outcomes were associated with each other at subsequent time points, confirming predictive validity. CONCLUSIONS: This is the first study of the validity of a stroke scale in patients treated with effective stroke therapy. The NIHSS appeared to be valid in patients with acute stroke and for finding treatment-related differences. The scale was valid when used serially over time after stroke, up to 3 months, and showed good agreement with other measures of outcome.

Brain↗

Does the National Institutes of Health Stroke Scale favor left hemisphere strokes? NINDS t-PA Stroke Study Group.

BACKGROUND AND PURPOSE: The National Institutes of Health Stroke Scale (NIHSS) is a valid, reproducible scale that measures neurological deficit. Of 42 possible points, 7 points are directly related to measurement of language compared with only 2 points related to neglect. METHODS: We examined the placebo arm of the NINDS t-PA stroke trial to test the hypothesis that the total volume of cerebral infarction in patients with right hemisphere strokes would be greater than the volume of cerebral infarction in patients with left hemisphere strokes who have similar NIHSS scores. The volume of stroke was determined by computerized image analysis of CT films and CT images stored on computer tape and optical disks. Cube-root transformation of lesion volume was performed for each CT. Transformed lesion volume was analyzed in a logistic regression model to predict volume of stroke by NIHSS score for each hemisphere. Spearman rank correlation was used to determine the relation between the NIHSS score and lesion volume. RESULTS: The volume for right hemisphere stroke was statistically greater than the volume for left hemisphere strokes, adjusting for the baseline NIHSS (P<0. 001). For each 5-point category of the NIHSS score <20, the median volume of right hemisphere strokes was approximately double the median volume of left hemisphere strokes. For example, for patients with a left hemisphere stroke and a 24-hour NIHSS score of 16 to 20, the median volume of cerebral infarction was 48 mL (interquartile range 14 to 111 mL) as compared with 133 mL (interquartile range 81 to 208 mL) for patients with a right hemisphere stroke (P<0.001). The median volume of a right hemisphere stroke was roughly equal to the median volume of a left hemisphere stroke in the next highest 5-point category of the NIHSS. The Spearman rank correlation between the 24-hour NIHSS score and 3-month lesion volume was 0.72 for patients with left hemisphere stroke and 0.71 for patients with right hemisphere stroke. CONCLUSIONS: For a given NIHSS score, the median volume of right hemisphere strokes is consistently larger than the median volume of left hemisphere strokes. The clinical implications of our finding need further exploration.

Brain↗

Agreement and variability in the interpretation of early CT changes in stroke patients qualifying for intravenous rtPA therapy.

BACKGROUND AND PURPOSE: Ischemic changes identified on CT scans performed in the first few hours after stroke onset, which are thought to possibly represent early cytotoxic edema and development of irreversible injury, may have important implications for subsequent treatment. However, insecurity and conflicting data exist over the ability of clinicians to correctly recognize and interpret these changes. We performed a detailed review of selected baseline CT scans from the NINDS rt-PA Stroke Trial to test agreement among experienced stroke specialists and other physicians on the presence of early CT ischemic changes. METHODS: Seventy baseline CT scans from the NINDS Stroke Trial were read and classified for the presence or absence of various early findings of ischemia by 16 individuals, including NINDS trial investigators, other neurologists, other emergency medicine physicians, and radiology or stroke fellows. CT scans included normal scans and scans from patients who later developed symptomatic intracranial hemorrhage, as well as scans on which the NINDS rt-PA Stroke Trial neuroradiologist identified clear-cut early CT changes. For each CT finding, kappa-statistics were used to assess the proportion of agreement beyond chance. RESULTS: kappa-Values (95% confidence interval [CI]) ranged from 0.20 (-0.20, 0.61) (fair agreement) to 0.41 (0.37, 0.45) (moderate agreement) among the 16 viewers, and the kappa-value was only 0.39 (0.29, 0.49) (fair) in answer to the question "do early CT changes involve more than one third of the MCA [middle cerebral artery] territory?" There was substantial variability within each specialty group and between groups. kappa-Values were only fair to moderate even among physicians experienced in selecting and treating acute stroke patients with rtPA. Observed agreement ranged from 68% to 85%. Physicians agreed on the finding of early CT changes involving >33% of the MCA territory 77% of the time, although the kappa-value of 0.39 suggested only moderate agreement beyond chance. CONCLUSIONS: There is considerable lack of agreement, even among experienced clinicians, in recognizing and quantifying early CT changes. Improved methods of recognizing and quantifying early ischemic brain damage are needed.

Cerebrovascular Disorders↗

The effect of pregnenolone 16alpha-carbonitrile on the pharmacokinetics and metabolism of dapsone in rats.

The purpose of this study was to evaluate the effect of pregnenolone 16 alpha-carbonitrile (PCN) on the interconversion pharmacokinetics and metabolism of dapsone. To determine microsomal CYP3A activity and protein, eight rats (4 PCN, 4 corn oil) received a 1 mg kg(-1) intravenous bolus dose of dapsone, followed by blood and urine sampling. The formation clearance of dapsone hydroxylamine (CLf DDS-NOH) was calculated from the obtained samples. Interconversion pharmacokinetics estimates were obtained after 10 rats (5 PCN, 5 control) received 1 mg kg(-1) dapsone or 1.17 mg kg(-1) monoacetyldapsone, with a 24-h wash-out. Results from the interconversion analysis demonstrated that PCN significantly increased systemic clearance (CLs) of dapsone, but not its interconversion. The in-vivo/in-vitro correlation study demonstrated that PCN significantly increased CLs of dapsone (8.55 to 16.39mLmin(-1); P<0.01) and CLf DDS-NOH (0.13 to 0.18mLmin(-1); P<0.01). PCN treatment produced a 69% increase in CYP3A protein, and increased 6beta- and 2beta-hydroxytestosterone formation rates. Significant correlations were found between CLf DDS-NOH and either 6beta- (r2 = 0.925), 2beta-hydroxytestosterone (r2 = 0.92), or CYP3A1/2 protein (r2= 0.60). We conclude that PCN treatment produces significant increases in CLs (dapsone) and CLf (DDS-NOH) in rats. These changes were not due to changes in the reversible metabolism of dapsone. These results suggest that the formation clearance of dapsone hydroxylamine reflects alterations in CYP3A activity, despite the fact that it accounted for a small part of the systemic clearance of dapsone.

Animals↗

[The relation between mitochondrial DNA mutation and aminogly- coside antibiotics-induced deafness].

OBJECTIVE: To nvestigate the relation between mitochondrial DNA mutation and aminoglycoside antibiotics-induced deafness. METHODS: Mitochondrial DNA (mtDNA) of peripheral blood from 48 sporadic cases was analysed using PCR-BsmAI digestion and PCR-direct DNA silver sequencing. RESULTS: Six of 48 sporadic patients had A to G mutation in 12S rRNA gene of mtDNA at nucleotide 1555. CONCLUSION: The results suggest that mtDNA 1555(G) mutation is related to the occurring of aminoglycoside antibiotics-induced deafness which can cause genetic susceptibility to aminoglycoside antibotics ototoxicity.

Adolescent↗

VEGF increases retinal vascular ICAM-1 expression in vivo.

PURPOSE: Intraocular injections of vascular endothelial growth factor (VEGF), a peptide implicated in the pathogenesis of diabetic retinopathy, can induce retinal ischemia. Diabetic retinal ischemia may be caused, in part, by the adhesion of leukocytes to the retinal vasculature. In this study, the ability of VEGF to increase the expression of intercellular adhesion molecule-1 (ICAM-1) and other adhesion molecules in capillary endothelium and the retinal vasculature was examined. METHODS: The expression of ICAM-1, vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and P-selectin on human brain capillary endothelial cell monolayers exposed to VEGF was quantitated by immunoassay. The effect of VEGF on retinal vascular ICAM-1 expression was determined in ICAM-1 immunofluorescence studies of retinal flat-mounts and in RNase protection assays. RESULTS: VEGF increased capillary endothelial cell ICAM-1 levels in a dose- and time-dependent manner (6-24 hours, plateau after 6 hours; EC50, 25 ng/ml). VEGF failed to alter E-selectin, P-selectin, or VCAM-1 levels under the conditions tested. Intravitreal injections of pathophysiologically relevant concentrations of VEGF increased ICAM-1 protein and mRNA levels in the retinal vasculature. CONCLUSIONS: VEGF increases retinal vascular ICAM-1 expression. VEGF-induced increases in ICAM-1 may promote retinal leukostasis in diabetic eyes.

Animals↗

Pharmacokinetics and therapeutic efficacy of rimantadine in horses experimentally infected with influenza virus A2.

OBJECTIVE: To determine pharmacokinetics of single and multiple doses of rimantadine hydrochloride in horses and to evaluate prophylactic efficacy of rimantadine in influenza virus-infected horses. ANIMALS: 5 clinically normal horses and 8 horses seronegative to influenza A. PROCEDURE: Horses were given rimantadine (7 mg/kg of body weight, i.v., once; 15 mg/kg, p.o., once; 30 mg/kg, p.o., once; and 30 mg/kg, p.o., q 12 h for 4 days) to determine disposition kinetics. Efficacy in induced infections was determined in horses seronegative to influenza virus A2. Rimantadine was administered (30 mg/kg, p.o., q 12 h for 7 days) beginning 12 hours before challenge-exposure to the virus. RESULTS: Estimated mean peak plasma concentration of rimantadine after i.v. administration was 2.0 micrograms/ml, volume of distribution (mean +/- SD) at steady-state (Vdss) was 7.1 +/- 1.7 L/kg, plasma clearance after i.v. administration was 51 +/- 7 ml/min/kg, and beta-phase half-life was 2.0 +/- 0.4 hours. Oral administration of 15 mg of rimantadine/kg yielded peak plasma concentrations of < 50 ng/ml after 3 hours; a single oral administration of 30 mg/kg yielded mean peak plasma concentrations of 500 ng/ml with mean bioavailability (F) of 25%, beta-phase half-life of 2.2 +/- 0.3 hours, and clearance of 340 +/- 255 ml/min/kg. Multiple doses of rimantadine provided steady-state concentrations in plasma with peak and trough concentrations (mean +/- SEM) of 811 +/- 97 and 161 +/- 12 ng/ml, respectively. Rimantadine used prophylactically for induced influenza virus A2 infection was associated with significant decreases in rectal temperature and lung sounds. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of rimantadine to horses can safely ameliorate clinical signs of influenza virus infection.

Administration, Oral↗

Insulin-induced vascular endothelial growth factor expression in retina.

PURPOSE: Clinical studies have demonstrated that intensive insulin therapy causes a transient worsening of retinopathy. The mechanisms underlying the initial insulin-induced deterioration of retinal status in patients with diabetes remain unknown. Vascular endothelial growth factor (VEGF) is known to be operative in the pathogenesis of diabetic retinopathy. The current study was conducted to characterize the effect of insulin on retinal VEGF gene expression in vitro and in vivo. METHODS: The effect of insulin on VEGF expression in vivo was examined by in situ hybridization studies of rat retinal VEGF transcripts. To examine the mechanisms by which insulin regulates VEGF expression, human retinal pigment epithelial (RPE) cells were exposed to insulin, and VEGF mRNA levels were quantified with RNase protection assays (RPAs). Conditioned media from insulin-treated RPE cells were assayed for VEGF protein and capillary endothelial cell proliferation. The capacity of insulin to stimulate the VEGF promoter linked to a luciferase reporter gene was characterized in transient transfection assays. RESULTS: Insulin increased VEGF mRNA levels in the ganglion, inner nuclear, and RPE cell layers. In vitro, insulin increased VEGF mRNA levels in human RPE cells and enhanced VEGF promoter activity without affecting transcript stability. Insulin treatment also increased VEGF protein levels in conditioned RPE cell media in a dose-dependent manner with a median effective concentration of 5 nM. The insulin-conditioned RPE cell media stimulated capillary endothelial cell proliferation, an effect that was completely blocked by anti-VEGF neutralizing antibody. CONCLUSIONS: Insulin increases VEGF mRNA and secreted protein levels in RPE cells through enhanced transcription of the VEGF gene. Intensive insulin therapy may cause a transient worsening of retinopathy in patients with diabetes through increased retinal VEGF gene expression.

Animals↗

Portal hemodynamics in cirrhotics with portal hypertension using color Doppler velocity profile.

OBJECTIVE: To investigate portal hemodynamics and its correlation with esophageal variceal bleeding (EVB) in cirrhotics with portal hypertension by using a newly-developed technique, color Doppler velocity profile (CDVP). METHODS: Hemodynamics of portal trunk (PT), right anterior branch (RAB) and splenic vein (SV) were evaluated in 48 cirrhotics with portal hypertension and 35 normal volunteers by CDVP. The parameters included maximum cross-sectional velocity (CS-Vmax), flow volume, congestion index (CI), profile parameter N and pattern of flow curve. Stepwise logistic regression model was employed to determine EVB-relating factors in cirrhotics. RESULTS: CS-Vmax in PT and RAB was significantly lower in cirrhotic group than that of normal group, being 14.91 +/- 3.08 cm/s, 9.44 +/- 2.70 cm/s vs 30.52 +/- 6.75 cm/s, 12.82 +/- 2.69 cm/s, respectively (P < 0.01 for both). Flow volume of PT and SV was significantly higher in cirrhotic group compared with that of normal group, being 25.16 +/- 10.48 ml.min-1.kg-1, 15.83 +/- 9.18 ml.min-1.kg-1 vs 20.43 +/- 5.57 ml.min-1.kg-1, 5.81 +/- 2.04 ml.min-1.kg-1, respectively (P < 0.01 for both). CI of PT, RAB and SV was significantly higher in cirrhotic group than in normal group, being 0.142 +/- 0.0654, 0.105 +/- 0.0496, 0.0884 +/- 0.0431 vs 0.0326 +/- 0.0142, 0.0757 +/- 0.0342, 0.0483 +/- 0.0230, respectively (P < 0.01 for all). In dynamic variation of flow volume over time, RAB and SV in cirrhotic group increasingly presented flat pattern and periodically changed pattern, respectively (P < 0.01 for both). Between cirrhotic subgroups without and with EVB history, there were significant differences in flow volume, CI and N value of SV, splenic size, degree of esophageal varices (EV) and portal hypertensive gastropathy (PHG), and stepwise logistic regression revealed that N value of SV, splenic size, degree of EV and PHG were four independent factors in relation to EVB. EVB scores calculated from the regression equation had a close correlation with EVB. In patients with EVB score > 0, 88.9% of them had EVB, and in those with EVB < 0, 76.9% of them had no history of EVB. CONCLUSION: In cirrhotics with portal hypertension, portal venous system has the features of elevated vascular resistance and hyperdynamics, and the latter mainly results from increased blood flow in SV. EVB score may become a valuable parameter in predicting occurrence of EVB.

Adolescent↗