Effects of hepatitis B virus antigens on interferon-gamma production of peripheral blood mononuclear cells from hepatitis B virus carriers and healthy individuals

BACKGROUND

Although the precise mechanisms of persistent infection by hepatitis B virus are not yet known, several lines of studies suggest that hepatitis B e antigen in sera might modulate the immune response of the host. The aim of this study was to clarify the effects of hepatitis B virus antigen on cytokine production of lymphocytes.

METHODS

We studied the effects of recombinant hepatitis B core antigen and surface antigen on interferon-gamma production of phytohemagglutinin-stimulated peripheral blood mononuclear cells from hepatitis B virus carriers and healthy individuals. Hepatitis B core antigen used in this study shared the antigenic site responsible for hepatitis B core and e antigen.

RESULTS

Although pre-incubation of peripheral blood mononuclear cells with hepatitis B core/e antigen followed by stimulation with phytohemagglutinin significantly reduced the production of interferon-gamma, pre-incubation with hepatitis B surface antigen did not affect them.

CONCLUSIONS

These results indicate that hepatitis B core/e antigen has the ability to inhibit interferon-gamma production of lectin-stimulated peripheral blood mononuclear cells in vitro, suggesting that secretion of hepatitis B e antigen into sera might be how hepatitis B virus escapes the immuno-surveillance system of the host.

Transthoracic Doppler assessment of pattern of left ventricular dysfunction in hypertensive heart disease: combined analysis of mitral and pulmonary venous flow velocity patterns

Although mitral flow velocity pattern changes with the progression of left ventricular (LV) diastolic dysfunction, it lacks predictive value in individual patients because of pseudonormalization in the presence of congestive heart failure and many physiologic and pathologic contributors to the mitral flow velocity pattern. To determine whether analysis of pulmonary venous flow velocity patterns complements the information obtainable from the mitral flow velocity patterns in the evaluation of patterns of LV dysfunction of hypertensive heart disease in individual patients, the ratio of the peak early diastolic filling velocity/peak filling velocity at atrial contraction (E/A ratio) in the mitral flow velocity pattern and the ratio of the peak systolic forward flow velocity (S)/peak diastolic forward flow velocity (D) (S/D ratio) in the pulmonary venous flow velocity pattern by the transthoracic approach were determined in 107 hypertensive patients with and without congestive heart failure. Age-related normal values of the E/A and S/D ratios were determined in 61 normal subjects and used to judge the normality or abnormality of the patterns. Results of the study indicate that (1) although an increased mitral E/A ratio is strongly indicative of heart failure with normal LV systolic function, the mitral E/A ratio is frequently within the normal range in hypertensive patients with heart failure; (2) association of decreased pulmonary venous S/D ratios with a normal mitral flow velocity pattern indicates the presence of heart failure as a result of LV systolic dysfunction that is usually observed at the most advanced pattern of LV dysfunction; (3) mild LV diastolic dysfunction is likely to exist in patients with normal E/A ratios if the pulmonary venous S/D ratio is higher than normal value; (4) predictive accuracy in the detection of LV systolic and diastolic dysfunction would be improved if both mitral and pulmonary venous flow velocity patterns rather than the mitral flow velocity pattern alone were analyzed. In conclusion, analysis of pulmonary venous flow velocity recordings improves accuracy and reliability of the Doppler assessment of LV systolic and diastolic dysfunction, particularly in individual hypertensive patients with normal mitral flow velocity patterns.

Hepatitis C virus genotype and RNA titer in the progression of type C chronic liver disease

Hepatitis C virus genotype and the amounts of circulating HCV RNA are the most important factors in determining the efficacy of interferon therapy for chronic hepatitis C. To clarify the correlation of these two factors to the progression of liver disease, we classified 148 Japanese patients with type C chronic liver disease into genotypes and also measured their HCV RNA titers (logarithmic transformed copy number/ml serum) by competitive reverse transcription-polymerase chain reaction. We found type II in 23 (76.7%) of 30 patients with chronic persistent hepatitis, 34 (79.1%) of 43 with chronic active hepatitis, 29 (72.5%) of 40 with cirrhosis and 30 (85.7%) of 35 with hepatocellular carcinoma. Thus, there was no significant difference in the prevalence of type II among the various stages of chronic liver disease. We also found the RNA titer to be significantly higher in patients with chronic active hepatitis (8.0 +/- 0.8) than in those with chronic persistent hepatitis (7.0 +/- 1.0, p < 0.001), and also those with cirrhosis (7.6 +/- 0.8, p < 0.05) or hepatocellular carcinoma (7.7 +/- 0.8, p < 0.05). When the titers were compared among genotypes, there was no significant difference between type II and III at any stage (type II vs. type III: chronic persistent hepatitis, 7.2 +/- 1.0 vs. 6.7 +/- 0.8; chronic active hepatitis, 8.1 +/- 0.7 vs. 7.8 +/- 1.0; cirrhosis, 7.7 +/- 0.8 vs. 7.8 +/- 0.7; hepatocellular carcinoma, 7.7 +/- 0.8 vs. 7.8 +/- 0.5). In conclusion, although genotype affects interferon therapy efficacy, it seems to have little influence on serum RNA levels and the progression of type C chronic liver disease.

Beta-adrenergic stimulation disassembles microtubules in neonatal rat cultured cardiomyocytes through intracellular Ca2+ overload

Catecholamine cardiotoxicity is attributable in part to Ca2+ overload. To test whether the cytoskeletal structures of microtubules in cardiomyocytes are reversibly injured by catecholamine through excessive Ca2+ influx, morphological changes in the microtubules of neonatal rat myocytes were studied by immunohistochemical technique during exposure to norepinephrine (NE). In intact myocytes, microtubules appeared as a filamentous network throughout the cytoplasm and around the nucleus. NE exposure (10 mumol/L) for > 30 minutes elicited microtubular disassembly in a duration-dependent fashion without any irreversible change in sarcomere structure, and this abnormality recovered within 24 hours after cessation of stimulation. Microtubular disruption scores obtained by semiquantitative assessment were significantly increased in a dose-dependent manner (10.8 +/- 4.0 in the control condition, 23.4 +/- 4.7 at 60 minutes with 10 mumol/L NE), whereas they were significantly attenuated by pretreatment with propranolol (100 mumol/L; score, 11.8 +/- 3.3) but not with phentolamine (100 mumol/L; score, 26.4 +/- 4.8). Isoproterenol (1 mumol/L) and denopamine (10 mumol/L) mimicked the effects of NE, but phenylephrine did not, indicating that NE-induced microtubular disassembly is mediated by beta 1-adrenergic receptor stimulation. This beta-adrenergic receptor-mediated insult was significantly attenuated by a decrease in Ca2+ concentration in the medium from 2 to 0.5 mmol/L and by pretreatment with diltiazem (1 mumol/L). In contrast, microtubular disassembly was induced by an increase in Ca2+ concentration in the medium and an administration of the Ca2+ ionophore A23187, even without beta-adrenergic receptor stimulation. Involvement of intracellular hypoxia and activation of Ca(2+)-calmodulin-dependent kinase or Ca(2+)-dependent neutral protease were excluded from possible mechanisms; however, inhibition of tubulin polymerization by excessive Ca2+ influx during beta-adrenergic receptor stimulation may be primarily involved. We conclude that microtubular structures that support cellular integrity are reversibly injured by beta-adrenergic receptor stimulation through excessive Ca2+ influx.

Precise positioning of intracranial small tumors to the linear accelerator's isocenter, using a stereotactic radiotherapy computed tomography system (SRT-CT)

RT-CT was developed as a simulator using CT scan for radiotherapy. Following three-dimensional treatment planning using CT images, the treatment center and treatment fields are projected to the patients' surface by laser beam on the C arm. The prototype had an accuracy of 3 mm which was equivalent to conventional X-ray simulators but was not adequate for use in stereotactic radiotherapy. A new RT-CT system was developed to have a precise localization capability for stereotactic radiotherapy. Using this stereotactic RT-CT (SRT-CT) after three-dimensional planning, the treatment center is projected to the stereotactic frame automatically. In this study, the values of the x, y and z coordinates of the target center determined by SRT-CT are compared with those determined by the traditional method using CT localizing plates. The discrepancies were within 1.0 mm in 90% and 1.5 mm in 100% of 30 measurements in 16 patients. The disadvantages of SRT-CT may be that the accuracy of localization depends on the quality of calibration of laser beams. The traditional CT localizing method has superiority over SRT-CT because of its solid coordinates but its accuracy is vulnerable to alignment of CT fiducial marker plates. Therefore, the SRT-CT and traditional CT localizing methods would be complementary to each other for precise localization.

Selective alpha 1-adrenergic inhibition improves decrease glucose disposal in patients with essential hypertension

This study evaluated insulin secretion and insulin sensitivity before and after short-term oral administration of doxazosin in patients with essential hypertension. The hypertensive group consisted of 11 nonobese subjects (aged 41.0 +/- 2.5 years (mean +/- SEM), body mass index 24.0 +/- 0.53 kg/m2). The normotensive group consisted of 12 subjects matched to the hypertensive group for age and body mass index. The hypertensive group showed significantly higher concentrations of prestimulated and stimulated plasma insulin and plasma C peptide than normal groups. The insulin-mediated glucose disposal rate during euglycaemic clamp (M-value) was significantly lower in the hypertensive group than in normal controls (7.32 +/- 0.56 vs 8.88 +/- 0.34 mg/kg/min, P < 0.05). After one month of doxazosin treatment blood pressure was significantly reduced (P < 0.05). The short-term administration of doxazosin improved the M-value significantly to 8.60 +/- 0.62 mg/kg/min without a significant change in stimulated plasma C-peptide level. These data show that hypertension is associated with increased insulin secretion and impaired insulin sensitivity. Selective alpha 1-adrenergic inhibition with doxazosin improves the decreased glucose disposal rate associated with hypertension.

Analysis of transmural trend of myocardial integrated ultrasound backscatter for differentiation of hypertrophic cardiomyopathy and ventricular hypertrophy due to hypertension

OBJECTIVES

This study was undertaken to differentiate hypertrophic cardiomyopathy from hypertensive hypertrophy using a newly developed M-mode format integrated backscatter imaging system capable of calibrating myocardial integrated backscatter with the power of Doppler signals from the blood.

BACKGROUND

Myocardial integrated ultrasound backscatter changes in patients with hypertrophic cardiomyopathy; however, it is unknown whether ultrasound myocardial tissue characterization may be useful in differentiating hypertrophic cardiomyopathy from hypertensive hypertrophy.

METHODS

Calibrated myocardial integrated backscatter and its transmural gradient were measured in the septum and posterior wall in 31 normal subjects, 13 patients with hypertensive hypertrophy and 22 patients with hypertrophic cardiomyopathy. The gradient in integrated backscatter was determined as the ratio of calibrated integrated backscatter in the endocardial half to that in the epicardial half of the myocardium.

RESULTS

Cyclic variation of integrated backscatter was smaller and calibrated myocardial integrated backscatter higher in patients with hypertrophied hearts than in normal subjects, but there were no significant differences in either integrated backscatter measure between patients with hypertensive hypertrophy and those with hypertrophic cardiomyopathy. Transmural gradient in myocardial integrated backscatter was present only in patients with hypertrophic cardiomyopathy (5.0 +/- 1.8 dB [mean +/- SD] for the septum; 1.2 +/- 1.6 dB for the posterior wall).

CONCLUSIONS

Hypertrophic cardiomyopathy and ventricular hypertrophy due to hypertension can be differentiated on the basis of quantitative analysis of the transmural gradient in integrated backscatter.

Adenosine blockade during reperfusion reverses the infarct limiting effect in preconditioned canine hearts

OBJECTIVES

The aim was to investigate whether adenosine release after reperfusion contributes to infarct limitation by ischaemic preconditioning.

METHODS

Dogs underwent preconditioning with four 5 min cycles of left anterior descending coronary artery (LAD) occlusion and reperfusion, followed by 90 min LAD occlusion and 5 h reperfusion with or without the non-specific adenosine receptor blocker, 8-phenyltheophylline (8-PT). Infarct size was assessed by a dual staining method with triphenyltetrazolium chloride and Evans blue. Blood flow measurements in the subendocardial region were made by infusion of coloured microspheres before occlusion and midway through the sustained occlusion. Transcardiac alteration of neutrophillic function was assessed by luminol-enhanced whole blood chemiluminescence induced by zymosan.

RESULTS

Infarct size was significantly reduced in the preconditioned dogs [12.5(SEM 4.0)%, n = 10, p < 0.01] compared with the control dogs [40.5(6.1)%, n = 10], an effect significantly reduced by the 8-PT treatment [23.4(4.9)%, n = 8]. Treatment with 8-PT without ischaemic preconditioning had no effect on infarct size [42.8(6.3)%, n = 7]. There was no difference in myocardial blood flow in the ischaemic or non-ischaemic subendocardial tissue between any pair of the four groups. The ratio of whole blood chemiluminescence in the cardiac vein to that in the carotid artery was considerably reduced in preconditioned dogs compared with that in control dogs after reperfusion. Myeloperoxidase activity in the ischaemic myocardium and the peripheral neutrophil count at the end of the experiment were both also decreased compared with control dogs. In preconditioned dogs treated with 8-PT, neutrophillic function in the coronary circulation after reperfusion was increased compared with that in both controls and preconditioned dogs with no 8-PT treatment. There was no difference in neutrophillic function between the 8-PT-treated dogs with or without ischaemic preconditioning. Treatment with 8-PT increased myeloperoxidase activity in the ischaemic myocardium of the preconditioned dogs, and no difference was seen in activity between dogs treated with 8-PT with or without ischaemic preconditioning.

CONCLUSIONS

An adenosine receptor blocker caused a moderate but significant reversal of infarct limitation by ischaemic preconditioning associated with a significant increase of neutrophillic function in the coronary circulation during early reperfusion.

IgG and IgM core antibodies and viral replication in hepatitis C virus carriers

We studied IgG and IgM antibodies to hepatitis C virus core protein (anti-HCVcore) in relation to serum virus RNA levels in 71 hepatitis C virus carriers. Viremic levels ranged from 10(4)-10(9) copies/ml and were high in 34 chronic active hepatitis patients compared with 17 asymptomatic carriers and 20 cases of chronic persistent hepatitis (p < 0.01). IgG anti-HCVcore was found in 67/71 (94%), but four asymptomatic carriers with low levels of viremia (10(4)-10(5.5) copies/ml) tested negative. IgM anti-HCVcore was found in patients with high levels of viremia (10(8)-10(9) copies/ml), and one (6%) asymptomatic carrier and nine (26%) chronic active hepatitis patients tested positive. In chronic hepatitis patients, viremic levels were significantly higher in cases positive for IgM anti-HCVcore than in negative ones (p < 0.01). However, no correlation was found between the occurrence of IgM anti-HCVcore and serum aminotransferase levels or the histologic activity index. These findings suggest that although IgG anti-HCVcore is sensitive, low viremic patients can escape this screening, and that the IgM anti-HCVcore is induced in association with high levels of virus replication.

Split dose iodine-123-IMP SPECT: sequential quantitative regional cerebral blood flow change with pharmacological intervention

At least two quantitative rCBF measurements are needed to evaluate rCBF changes with pharmacological intervention. We have developed the split dose 123I-IMP SPECT method, which enables measurement of rCBF to be repeated in a short time.

METHODS

Thirty-one cerebrovascular disease patients were investigated to assess reproducibility and vasoreactivity to acetazolamide. During 44-min dynamic SPECT imaging, 123I-IMP injection and respective arterial sampling were performed twice at an interval of about 25 min. The rCBF values were calculated using a microsphere model in which the washout of 123I-IMP from the brain can be negligible in the first several minutes after injection. For the second rCBF measurement, the remaining activity due to the first 123I-IMP injection was estimated and subtracted from the total brain activity.

RESULTS

In ten patients, two consecutive resting mean rCBF values in the MCA territory (CBF1 and CBF2) had good correlation (CBF1 = 47.4 +/- 4.0 (ml/min/100 ml: mean +/- s.d.), CBF2 = 45.2 +/- 8.2, CBF2 = 0.900*CBF1 + 2.9, r = 0.915). In 11 patients with occlusive lesions in the unilateral ICA system, mean rCBF in the MCA territory was increased by only 27.7% +/- 14.0% in the affected side by a 1-g intravenous acetazolamide injection, while 44.5% +/- 12.3% increase was found in the nonaffected side. In 10 patients without a major arterial lesion, a 49.7% +/- 17.0% increase of rCBF was demonstrated.

CONCLUSIONS

This split dose method 123I-IMP SPECT can be useful to estimate vascular reserve.

In vivo osmoregulation of Na/myo-inositol cotransporter mRNA in rat kidney medulla

myo-Inositol, a major compatible osmolyte in renal medulla, is accumulated in kidney-derived epithelial cells cultured in hypertonic media via Na/myoinositol cotransporter (SMIT). The altered medium osmolality of Madin-Darby canine kidney cells leads to changes in the transcription of the SMIT gene and mRNA abundance. To investigate whether SMIT is regulated by tonicity in vivo, renal medullary myoinositol and SMIT mRNA was measured in rats in hydrated and dehydrated states. Rats were divided into two groups: (1) hydrated rats, free access to 3% sucrose water; (2) dehydrated rats, 3 days of water deprivation. Urine sodium, potassium, urea, and osmolality in dehydrated rats were significantly higher than in hydrated rats. Renal medullary sodium, urea, and myo-inositol in dehydrated rats were significantly higher than in hydrated rats. Northern analysis revealed that there was a message hybridized to SMIT cDNA in the cortex and outer and inner medulla of the kidney. Compared with hydrated rats, SMIT mRNA in dehydrated rats was 2.6-fold higher in the outer medulla and 2.5-fold higher in the inner medulla. These results indicate that there is osmoregulatory SMIT in the outer and inner medulla of the kidney and that myo-inositol accumulation in this region is probably due to the increased expression of the SMIT gene.

Estrogen regulation of the insulin-like growth factor I gene transcription involves an AP-1 enhancer

As a step toward elucidating the physiological role of insulin-like growth factor-I (IGF-I) in mediating estrogen action, we sought to determine the molecular basis of the phenomenon. In HepG2 cells expressing exogenous estrogen receptors (ER), a reporter gene plasmid containing 600 base pairs of the chicken IGF-I promoter enhanced expression of luciferase 8.6-fold in response to 10(-6) M 17 beta-estradiol, indicating that the IGF-I promoter is a target of estrogen regulation. Although no conventional estrogen-responsive element was identified within the promoter fragment, the AP-1 motif located therein was shown to be essential; the estrogen-responsive enhancement of the Fos-Jun binding to the AP-1 motif, which takes place by means of post-translational modification, mediates the estrogen action. A direct or indirect interaction between the estrogen-ER complex and the Fos-Jun complex seems to facilitate the Fos-Jun binding to the target DNA. Although ER binding to the target DNA was not considered to be involved in the signaling pathway, the DNA binding domain-deficient ER did not mediate the phenomenon, providing support for the existence of a unique function of the DNA binding domain of ER in facilitating some protein-protein interaction. In conclusion, our present observations demonstrate that the chicken IGF-I gene promoter is controlled by estrogen through a unique pathway involving Fos, Jun, and the DNA binding domain of ER.

Immunohistochemical detection of Fas antigen in liver tissue of patients with chronic hepatitis C

Apoptosis is a type of cell death that occurs in acute or chronic hepatitis. It has been suggested to be mediated through Fas antigen. To evaluate the role of apoptosis on liver injury of chronic hepatitis C, we studied the expressions of Fas antigen and hepatitis C virus antigen (core antigen) immunohistochemically. Forty liver biopsy samples from patients with type C chronic liver disease were immunostained for Fas antigen and hepatitis C virus antigen. Expression of Fas antigen was found mainly in the cytoplasm of hepatocytes, and these positive cells were found particularly among infiltrating lymphocytes at the advancing edges of "piecemeal necrosis." The histological activity index showed inflammation of both portal and periportal areas to be more severe in the Fas antigen-positive samples than in the Fas antigen-negative ones (p < 0.05 and p < 0.001, respectively). Furthermore, semiquantitative analysis revealed more expression of Fas antigen in the liver tissues with active inflammation than in those without it (p < 0.01). The prevalence of Fas antigen expression in the hepatitis C virus antigen-positive group was higher than that in the hepatitis C virus antigen-negative group (p < 0.05). Our findings suggest that Fas antigen expression (apoptosis) plays an important role in inflammation in the hepatitis C virus-infected liver, particularly in the active inflammation of chronic hepatitis C.

[The diagnosis of a mutation of the insulin receptor by non-radioisotropical RT-PCR-SSCP analysis]

We evaluated a 24 years old diabetes woman with type A insulin resistant (patient "Yakushima") who had some typical symptoms as acanthosis nigricans, hirsutism and virilization. Insulin binding to the patient's erythrocytes was significantly decreased to about 30% of the normal control. In order to determine the mutation of the insulin receptor, we used for reverse transcript-polymerase chain reaction-single strand conformation polymorphism (RT-PCR-SSCP) analysis without using radiolabeled materials. We also analysed the nucleotide sequence with non-isotropical probe. Our results suggested that the mutation was heterozygous, and the patient had a new missense mutation substituted Asn461 for Thr461 in the alpha-subunit.

Expression of hepatitis C virus in hepatocellular carcinoma

BACKGROUND

Epidemiologic studies have suggested a strong association between chronic hepatitis C virus (HCV) infection and the development of hepatocellular carcinoma (HCC). To investigate the possible role of HCV in the pathobiology of HCC, the authors studied the expression of HCV in 10 cases of HCC with chronic HCV infection.

METHODS

The core, envelope, and nonstructural (NS) 3 and 5 proteins were localized in liver and tumor tissues by the immunoperoxidase technique using mouse monoclonal antibodies to recombinant proteins or synthetic peptide of HCV. In addition, the positive and negative strands of HCV RNA were detected in the tissues by strand-specific reverse transcription/double polymerase chain reaction using primers for the 5'-nontranslated region.

RESULTS

The HCV proteins were expressed in three of nine HCC specimens tested (the core protein in three HCC, the envelope, NS3 and NS5 proteins in one HCC) and in two of nine nontumorous liver specimens adjacent to the HCC (the core protein in two specimens, envelope, NS3 and NS5 proteins in one specimen). Positive-stranded HCV RNA was detected in all tumorous and nontumorous specimens except in one tumor. Negative-stranded HCV RNA was found in six of nine HCC tested and in all nontumorous livers.

CONCLUSIONS

These findings suggest that HCV persists in hepatocytes during malignant transformation, although secondary infection of tumor cells by HCV cannot be excluded. Some HCC appear to support replication and expression of HCV.

Serial quantitative analysis of serum hepatitis C virus RNA level in patients with acute and chronic hepatitis C

To examine changes in the serum level of hepatitis C virus RNA in acute and chronic phases of hepatitis C virus infection, we tested serial serum samples of six patients with acute hepatitis C (posttransfusion: three; sporadic: three) and 11 patients with chronic hepatitis C using a competitive reverse transcription and polymerase chain reaction assay. The internal standard consisted of known amounts of synthetic mutated RNA. No patient with acute hepatitis showed resolution during the follow-up period (24-57 weeks). In posttransfusion cases, titers of hepatitis C virus RNA (log10[hepatitis C virus RNA copies/ml serum]) rose to a high level (7.5-9.5) in the early phase of infection (4-12 weeks after the transfusions) in association with the first serum alanine aminotransferase peaks. Titers of hepatitis C virus RNA then decreased, while serum alanine aminotransferase levels fluctuated with multiple peaks. In sporadic cases, titers of hepatitis C virus RNA had already reached a high level (7.0-7.5) at the first alanine aminotransferase peaks 2-3 weeks after the clinical onset. In chronic hepatitis C virus infection, titers of hepatitis C virus RNA remained high for follow-up periods of 6-12 years in patients with chronic active hepatitis. These results indicate that the replication of hepatitis C virus rose to a high level in the early phase of infection and that a high replicative level of hepatitis C virus might be related with progression of liver disease in the chronic phase of infection.

Platelet activation in diabetic patients with asymptomatic atherosclerosis

We studied 27 non-insulin-dependent diabetics without apparent atherosclerosis (AS) to investigate whether abnormal platelet function is related to asymptomatic atherosclerosis in diabetes mellitus. The degree of AS was quantitatively evaluated by determining the intimal plus medial thickness (IMT) of the carotid artery wall with ultrasound high-resolution B-mode imaging. Based on our previous finding that the upper threshold of the IMT was 1.1 mm in healthy subjects, the patients were divided into the AS-positive group with the IMT > 1.1 mm, (n = 17) and the AS-negative group with the IMT < 1.1 mm (n = 10). Among five variables measured as the factors concerned with thrombogenesis, only plasma levels of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) were significantly higher in the AS-positive group than in the AS-negative group. Chronic administration of pentoxifylline (300 mg/day) significantly reduced the abnormally high plasma levels of beta-TG and PF4 in 7 patients of the AS-positive group to normal levels, without lowering the normal plasma beta-TG and PF4 levels in the remaining 10 patients. Pentoxifylline treatment did not affect the plasma levels of the 3 other variables, von Willebrand factor, 6-keto prostaglandin F1 alpha and thromboxane B2. This study suggests that the progress of atherosclerosis in diabetes mellitus is associated with in vivo platelet activation and platelet activation does not occur in diabetics without carotid atherosclerosis. Pentoxifylline may impede the vicious cycle in which atherosclerosis is accelerated by platelet activation.

Impaired gastric mucosal energy metabolism in congestive gastropathy in cirrhotic patients

To clarify the characteristics of congestive gastropathy, we investigated gastric mucosal hemodynamics and energy metabolism in cirrhotic patients, using a reflectance spectrophotometry system and high performance liquid chromatography. The index of the gastric mucosal blood volume of cirrhotic patients with esophageal varices was significantly higher, and the index of gastric mucosal blood oxygenation significantly lower, than those in controls, thus indicating congestion and hypoxia in the gastric mucosa. Energy charge levels in the gastric mucosa of cirrhotic patients with esophageal varices were also significantly decreased. The energy charge level showed a strong linear correlation with the index of mucosal blood oxygenation in the antral (r = 0.996, P < 0.01) and body (r = 0.994, P < 0.01) mucosa of the stomach. These findings suggest that congestive gastropathy in a portal hypertensive state causes hypoxia in the gastric mucosa, leading to a mucosal energy deficit that may increase mucosal susceptibility to aggressive factors.

Hepatitis C virus replication and antibody responses toward specific hepatitis C virus proteins

We assessed the correlation between hepatitis C virus replication and antibody responses toward hepatitis C virus core (C22-3), NS3 (C33C), NS4 (5-1-1 and C100-3) and NS5 proteins in 59 virus carriers. The concentration of serum hepatitis C virus RNA was determined by a competitive reverse transcription-polymerase chain reaction assay. All 50 patients with high viremic levels of > or = 10(6) copies/mL had antibodies to C22-3 and C33C. Antibodies to 5-1-1, C100-3 and NS5 proteins were detected less frequently (p < 0.01) in 72% (36 of 50), 78% (39 of 50) and 84% (32 of 38) of such patients, respectively. As for the nine patients with low viremic levels of < 10(6) copies/mL, antibodies to C22-3, C33C, 5-1-1 and NS5 proteins were detected in only one patient (11%), which was significantly less than the frequency for highly viremic patients (p < 0.01). Antibody to C100-3 was also found less frequently in only four patients (44%) (p < 0.05). Thus, only four (44%) of the nine low viremic patients tested positive for any antibody compared with all 50 highly viremic patients (p < 0.01). These results indicate that highly viremic carriers can be detected by the presence of hepatitis C virus antibodies, but a considerable proportion of low viremic carriers may not show any serological evidence of hepatitis C virus infection.

Mitogen-activated protein kinase and its activator are regulated by hypertonic stress in Madin-Darby canine kidney cells

Madin-Darby canine kidney cells behave like the renal medulla and accumulate small organic solutes (osmolytes) in a hypertonic environment. The accumulation of osmolytes is primarily dependent on changes in gene expression of enzymes that synthesize osmolytes (sorbitol) or transporters that uptake them (myo-inositol, betaine, and taurine). The mechanism by which hypertonicity increases the transcription of these genes, however, remains unclear. Recently, it has been reported that yeast mitogen-activated protein (MAP) kinase and its activator, MAP kinase-kinase, are involved in osmosensing signal transduction and that mutants in these kinases fail to accumulate glycerol, a yeast osmolyte. No information is available in mammals regarding the role of MAP kinase in the cellular response to hypertonicity. We have examined whether MAP kinase and MAP kinase-kinase are regulated by extracellular osmolarity in Madin-Darby canine kidney cells. Both kinases were activated by hypertonic stress in a time- and osmolarity-dependent manner and reached their maximal activity within 10 min. Additionally, it was suggested that MAP kinase was activated in a protein kinase C-dependent manner. These results indicate that MAP kinase and MAP kinase-kinase(s) are regulated by extracellular osmolarity.

Coronary atherosclerosis reduced in patients with familial hypercholesterolemia after intensive cholesterol lowering with low-density lipoprotein-apheresis: 1-year follow-up study. The Osaka LDL-Apheresis Multicenter Trial Group

To test the hypothesis that aggressive cholesterol lowering results in a rapid regression of coronary atherosclerosis, the effect of low-density lipoprotein (LDL)-apheresis for 1 year on coronary artery diameters was studied in patients with heterozygous familial hypercholesterolemia. LDL-apheresis was performed every 2 weeks in 13 patients with LDL-cholesterol levels > or = 200 mg/dL despite treatment with conventional dietary and drug therapies. Coronary arteriography was performed before and 1 year after the initiation of treatment. The LDL-cholesterol level was decreased by an average of 71% immediately after the initial LDL-apheresis and by 30% before the second apheresis. Such phasic changes were observed throughout the trial. Computer-assisted automated quantitative arteriograms analyzed 101 proximal coronary segments. The mean lumen diameter of angiographically normal sections of each segment was slightly but significantly increased from 2.93 +/- 0.89 mm at baseline to 3.05 +/- 0.93 mm at the follow-up arteriogram (P < 0.05); 54 of the 101 segments showed a lesion stenosed by 20% or more in diameter. The minimal diameter of individual lesions was also significantly increased from 2.17 +/- 0.67 mm to 2.36 +/- 0.76 mm (P < 0.05), and thus the diameter stenosis was significantly reduced from 32.3 +/- 10.5% to 28.2 +/- 12.1% (P < 0.05). It is concluded that 1 year of aggressive cholesterol lowering, using LDL-apheresis, can significantly reduce coronary atherosclerosis in patients with familial hypercholesterolemia.

Atherosclerosis in carotid artery of young IDDM patients monitored by ultrasound high-resolution B-mode imaging

Ultrasound high-resolution B-mode imaging was used to assess the carotid arteries in 105 patients with insulin-dependent diabetes mellitus (IDDM), 4-25 years of age, with duration of diabetes ranging from 0.5-17 years, 529 patients with non-insulin-dependent diabetes (NIDDM), 31-86 years of age, with duration of diabetes ranging from 0.5-49 years, and 104 nondiabetic healthy subjects, 7-76 years of age, to determine the intimal plus medial thickness (IMT) of the arterial wall. The IMT values for IDDM patients 10-19 years of age (0.525 +/- 0.123 mm, n = 68) or 20-25 years of age (0.696 +/- 0.124 mm, n = 14) were significantly greater than those in age-matched nondiabetic subjects (0.444 +/- 0.057 mm, n = 12, P = 0.01169; 0.538 +/- 0.098 mm, n = 34, P < 0.00006). NIDDM patients showed IMT values equivalent to those in normal adults > or = 20 years of age. Multiple regression analysis showed that IMT in IDDM patients was positively related to the duration of diabetes (P = 0.00061) as well as to age (P = 0.00046). No other possible risk factors, such as serum total cholesterol level, serum high-density lipoprotein (HDL)-cholesterol level, serum low-density lipoprotein-cholesterol level, serum triglycerides, serum lipoprotein(a) level, or systolic or diastolic blood pressure, have shown significant correlations with IMT in IDDM patients. However, non-HDL-cholesterol, smoking, and systolic hypertension were independently responsible for increases in IMT values of NIDDM patients as well as age and duration of diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of hepatitis C virus in hepatocellular carcinoma

BACKGROUND

Epidemiologic studies have suggested a strong association between chronic hepatitis C virus (HCV) infection and the development of hepatocellular carcinoma (HCC). To investigate the possible role of HCV in the pathobiology of HCC, the authors studied the expression of HCV in 10 cases of HCC with chronic HCV infection.

METHODS

The core, envelope, and nonstructural (NS) 3 and 5 proteins were localized in liver and tumor tissues by the immunoperoxidase technique using mouse monoclonal antibodies to recombinant proteins or synthetic peptide of HCV. In addition, the positive and negative strands of HCV RNA were detected in the tissues by strand-specific reverse transcription/double polymerase chain reaction using primers for the 5'-nontranslated region.

RESULTS

The HCV proteins were expressed in three of nine HCC specimens tested (the core protein in three HCC, the envelope, NS3 and NS5 proteins in one HCC) and in two of nine nontumorous liver specimens adjacent to the HCC (the core protein in two specimens, envelope, NS3 and NS5 proteins in one specimen). Positive-stranded HCV RNA was detected in all tumorous and nontumorous specimens except in one tumor. Negative-stranded HCV RNA was found in six of nine HCC tested and in all nontumorous livers.

CONCLUSIONS

These findings suggest that HCV persists in hepatocytes during malignant transformation, although secondary infection of tumor cells by HCV cannot be excluded. Some HCC appear to support replication and expression of HCV.