Effects of Z-100, a Mycobacterium-tuberculosis-derived arabinomannan, on the LP-BM5 murine leukemia virus infection in mice

OBJECTIVE

To investigate the effects of Z-100, an arabinomannan extracted from Mycobacterium tuberculosis, on the LP-BM5 murine leukemia virus (LP-BM5 MuLV) infection in mice.

METHODS

C57BL/6 mice infected intraperitoneally with 4.5 x 10(2) PFU/mouse of LP-BM5 MuLV (MAIDS mice) were treated intraperitoneally with a 10-mg/kg dose of Z-100 every other day beginning 1 day after the viral infection. MAIDS mice treated with Z-100 were compared with control mice (MAIDS mice treated with saline) for their survival and splenomegaly after LP-BM5 infection. Cytokine-producing profiles of splenic T cells from these two groups of mice were also compared.

RESULTS

When MAIDS mice treated with Z-100 were compared with those of control mice, a decrease in splenomegaly and lymphadenopathy was observed. Splenomegaly was markedly enhanced in MAIDS mice treated intraperitoneally with IL-4 or IL-10. When MAIDS mice were treated with Z-100, their survival rates were significantly increased compared to those of controls. Splenic T cells from control mice produced type-2 cytokines (IL-4 and IL-10). However, a decreased production of type-2 cytokines by splenic T cells from MAIDS mice treated with Z-100 was demonstrated.

CONCLUSION

Z-100 could decrease the severity of the LP-BM5 MuLV infection through the regulation of MAIDS-associated type-2 T-cell responses.

Pathogenic significance and organic virus levels in patients infected with TT virus

Previous reports documented the recovery of a DNA virus from a patient with posttransfusion non-A-G hepatitis and named TT virus (TTV). Although the virus was initially detected as a causative agent of hepatitis, there is doubt about its pathogenicity. The aim of this study was to clarify the relationship between TTV and liver diseases. Histopathological examination of liver biopsies from 14 patients with TTV genotype 1 positive non-B, non-C and non-G chronic hepatitis showed mild fibrosis and periportal/piecemeal necrosis. Using the real-time detection (RTD)-PCR method, we found that TTV DNA levels of genotype 1 in liver samples from 3 such patients were 100- to 1,000-fold higher than those in the paired serum samples. Further investigation using various tissues from 2 autopsies of patients with hepatitis C with hepatocellular carcinoma revealed that the concentrations of TTV DNA in the liver were also higher than in serum samples. However, the highest TTV DNA concentrations in these 2 autopsies were found in the lung and bone marrow, respectively. Our results suggest that TTV may replicate in various tissues including the liver and may cause only mild liver damage.

Strong association of a tumor necrosis factor-alpha promoter allele with cerebral malaria in Myanmar

To investigate the host genetic factors affecting the clinical course of falciparum malaria, polymorphism of the tumor necrosis factor-alpha (TNF-alpha) promoter region was analyzed in patients with cerebral malaria. Two hundred and forty-three Myanmar patients with falciparum malaria at Mae Sot Malaria clinic and Mae Sot General Hospital located at the border between Thailand and Myanmar, were included in this study. Among the patients (128 from Karen, 115 from Burma), 200 were uncomplicated and 43 had cerebral malaria. The TNF-alpha 5'- flanking region showed biallelic polymorphic sites at -238, -308, -857, -863, -1031, and there were 7 alleles (TNFP-A, B, C, D, M1, M4, M7) found in the patients from Myanmar. We found that the TNFP-D allele was significantly associated with cerebral malaria in the populations from Karen (Pc<0.0001, OR=124.86) and Burma (Pc<0.0001, OR=34.50). TNFP-D showed no significant linkage disequilibrium with any alleles of HLA-B or HLA-DRB1, suggesting that TNFP-D was primarily associated with cerebral malaria in Myanmar.

Late dissemination of fourth ventricle ependymoma: a case report

Dissemination of benign ependymoma is relatively rare, especially when a local tumor is under control. The majority of the failures take place within a few years after surgery. However, we experienced a case in which multiple spinal cord dissemination was found 13 years after resection of the fourth ventricle ependymoma without a local failure. A 38-year-old man had undergone a subtotal resection of the fourth ventricle ependymoma and radiation therapy to the posterior fossa when he was 25 years old. Follow-up MR imaging repeated once every one or two years detected no recurrence until he began to complain of lumbago and numbness of the right foot 13 years after the surgery. MR imaging revealed multiple nodules along the whole spinal cord. Examination of the cerebrospinal fluid detected tumor cells with ependymal cell features. He underwent radiation therapy to the whole spine, and remained stable at 18 months after the therapy. This case alerts us to the necessity for long-term radiological follow-up including the spinal cord even in benign ependymomas, although it is still not certain for how long and how often we should do it.

Susceptibility of thermally injured mice to cytomegalovirus infection

Thermally injured patients are very susceptible to infection with cytomegaloviruses. In this study a role of burn-associated type 2 T cell responses on the cytomegalovirus infection was examined in a mouse model of thermal injury. A predominance of type 2 T cell responses in splenic lymphocytes of thermally injured mice has been previously demonstrated. SCID mice inoculated with splenic T cells from thermally injured mice were susceptible to infection with a small amount (5 PFU/mouse) of murine cytomegalovirus (MCMV). Conversely, SCID mice inoculated with splenic T cells from normal mice were resistant to the same infection. High levels of IL-4 and IL-10, but not IFN-gamma and IL-2, were detected in sera of thermally injured mice (TI-mice) infected with MCMV when those were compared with sera of normal mice infected with MCMV. IL-4 and IL-10 (type 2 cytokines) were produced by splenic T cells from MCMV-infected TI-mice, when they were stimulated in vitro with anti-CD3 mAb. Type 1 cytokines (IFN-gamma and IL-2), however, were not produced by these T cells after the same stimulation. In contrast, splenic T cells from MCMV-infected normal mice produced type 1 cytokines by the stimulation with anti-CD3 mAb. These results suggest that the susceptibility of mice to MCMV infection is markedly influenced by burn-associated type 2 T cell responses.

Association of adhesion molecule PECAM-1/CD31 polymorphism with susceptibility to cerebral malaria in Thais

Adhesion molecules on endothelial cells are known to be important ligands for malaria infected red blood cells (PRBC) [Mol Biochem Parasitol, 76, (1996) 1], and may be involved in the pathogenic process of cerebral malaria (CM) which is the most serious complication of falciparum malaria, through enhancing micro embolism or sequestration in the capillaries of the brain. PECAM-1/CD31 is one of these candidate ligands and is coded by a polymorphic gene. Two hundred and ten Thai malaria patients (43 cerebral, 89 severe and 78 uncomplicated) were analyzed for their genetic polymorphism of CD31 to examine the clinical relationship between the disease and specific genotypes. Four alleles were defined 125 valine (V)-563 asparagine (N); 125V-563 serine (S); 125 leucine (L)-563N; and 125L-563S. We found that the frequency of the 125 V/V 563 N/N genotype was significantly high in CM patients as compared with severe cases without CM (P<0.01, OR=2.92), suggesting that this genotype is one of the risk factors for CM.

Ventricular echo beats and retrograde atrioventricular nodal exits in the dog heart: multiplicity in their electrophysiologic and anatomic characteristics

INTRODUCTION

A single ventricular echo beat frequently is induced in the dog heart by ventricular pacing, but it has not been investigated using a concomitant ablative technique. We studied the effects of ablating the anterior atrial input to the AV node on ventricular echo beats induced in the dog heart to evaluate their electrophysiologic characteristics, the anatomic reentrant circuit, and the retrograde AV nodal exits.

METHODS AND RESULTS

In 20 dogs, an epicardial radiofrequency current was applied to the right anterior septum in an attempt to ablate the anterior input to the AV node. Ventricular programmed stimulation was performed to evaluate the ventricular echo beat and the retrograde AV nodal exit before and after ablation. The AV junction was examined with light microscopy. Seventeen dogs in which the PR interval was prolonged significantly from 108+/-17 msec to 153+/-19 msec (P < 0.001) were selected for ventricular echo evaluation; 3 dogs in which persistent second- or third-degree AV block was induced by ablation were excluded. Ventricular echo beats, which were induced in 13 of 17 dogs, were classified into the anterior type (n = 6) or posterior type (n = 7) according to the earliest atrial activation site during the echo beat. The retrograde AV nodal exit site showed anterior-exit only (n = 10), posterior-exit only (n = 2), and dual-exit (n = 5) patterns. After ablation, the anterior-type ventricular echo beat was noninducible in all 6 dogs, whereas the posterior-type ventricular echo beat was noninducible in only 3 of 7 dogs. In 17 dogs, VA conduction was not demonstrated after ablation in 3 dogs, all of which showed the anterior-exit only pattern.

CONCLUSION

The effect of ablation on the ventricular echo beats and retrograde AV nodal exit site suggests multiplicity in their electrophysiologic and anatomic characteristics in the dog heart.

Randomized controlled clinical trial of lymphoblastoid interferon-alpha for chronic hepatitis C

Objective: Most of chronic hepatitis C patients with HCV-genotype 1 and a high virus load fail to eradicate the HCV-RNA by the interferon (IFN) or IFN/ribavirin therapy. But in these patients, IFN is often effective with regard to normalization of alanine aminotransferase (ALT). We had therefore the following two randomized controlled clinical trials to evaluate the effect of IFN which reduce ALT and maintain normalization of ALT. One approach (study 1) was to compare the efficacy of a 6 month course of three different dosages of recombinant IFN-alpha-2a in patients with chronic hepatitis C associated with HCV-genotype 1b and a high serum HCV-RNA level of more than 1 Meq/ml. Another approach (study 2) was to make clear the significance of an additional 6 month course of IFN in patients who had biochemical response during the first 6 month course of IFN (study 1). Methods: (1) Study 1; 45 patients with HCV-genotype 1b and a high serum HCV-RNA level of more than 1 Meq/ml were randomly assigned into three equal groups; group 1 was treated with 3 million units (MU), group 2 with 6 MU and group 3 with 9 MU. They were treated with IFN 3 times weekly for 6 months. Biochemical response was defined as normalization of ALT at the 6 month after initiation of IFN; (2) Study 2; Subsequently, of 23 patients with biochemical response by the first study, 22 were randomly assigned to two groups; patients in group A were continued to receive 3 MU of IFN-alpha-2a three times a week for an additional 6 months and patients in group B were discontinued IFN therapy. Results: (1) Study 1; One patient in group 1, three in group 2 and five in group 3 withdrew from IFN therapy because of IFN-related side-effects. Biochemical response was 10 (66.7%) patients of group 1,8 (53.3%) of group 2 and 5 (33%) of group 3 by the intention-to-treat (ITT) analysis. The biochemical response rate in group 1 was slightly higher than that in other two groups by the Cochran Armitage two-tailed test (P=0.066). With respect to serum HCV-RNA level, one patient in group 1, six patients in group 2 and four patients in group 3 became negative for HCV-RNA by reversed transcription nested-polymerase chain reaction (RT nested-PCR) at the end point of first 6 month course of IFN; (2) Study 2; The maintenance rate of ALT normalization was 88.9% (9/11) in group A and 11.1% (2/11) in group B. The maintenance rate of ALT normalization in group A was significantly higher than that in group B by the Fisher exact's test (P=0.0089). With respect to serum HCV-RNA level by RT nested-PCR, four patients in group A had negative HCV-RNA at the end of an additional IFN therapy. On the other hand, all the patients in group B had positive HCV-RNA at the same time. Conclusion: Our data suggested that a prolonged IFN therapy using a dose of 3 MU of IFN-alpha-2a is safe strategy to reduce ALT and to maintain ALT normalization in patients with HCV-genotype 1b and a high serum HCV-RNA level of more than 1 Meq/ml.

Genetic changes induced in human cells in Space Shuttle experiment (STS-95)

BACKGROUND

Results of past space experiments suggest that the biological effect of space radiation could be enhanced under microgravity. To assess the radiation risk for humans during long-term spaceflight, it is very important to clarify whether human cells exhibit a synergistic effect of radiation and microgravity.

HYPOTHESIS

If significant synergism occurs in human cells, genetic changes induced during spaceflight may be detected by using human tumor HCT-116 cells which are hypermutable due to a defect in the DNA mismatch repair system.

METHODS

Cultured HCT-116 cells were loaded on the Space Shuttle Discovery (STS-95) and grown during the 9-d mission. After landing, many single-cell clones were isolated, microsatellite repetitive sequences in each clone were amplified by PCR, and mutations in the microsatellite loci were detected as changes in the length of PCR fragments. Mutation frequencies of ouabain-resistant phenotype were also analyzed.

RESULTS

The frequencies of microsatellite mutations as well as ouabain-resistant mutations in the flight sample were similar to those of the ground control samples. Some cells were treated in space with bleomycin which mimics the action of radiation, but the frequencies of microsatellite mutations were not significantly different between the flight and the ground control samples.

CONCLUSION

Under the present flight conditions, neither space radiation (about 20 mSv during this mission) nor microgravity caused excess mutations in human cells.

Monocyte chemoattractant protein-1 enhances HSV-induced encephalomyelitis by stimulating Th2 responses

Monocyte chemoattractant protein (MCP)-1 has a pathogenic role in herpesvirus-induced encephalomyelitis (HSM). Anti-MCP-1 antibody greatly decreased HSM severity in mice infected with herpes simplex virus type 2 (HSM mice), compared with its effect in control HSM mice treated with rabbit immunoglobulin. HSM severity was markedly enhanced in mice previously treated with a mixture of interleukin (IL) 4 and -10. In response to stimulation with antigen, HSM mouse cells isolated from cerebrospinal fluids (CSF cells) produced IL-4 in culture fluids; however, IL-4 production decreased in CSF cells derived from HSM mice previously treated with anti-MCP-1 antibody. A macrophage population isolated in CSF cells from HSM mice (CSF-Mphi) produced MCP-1 in culture fluids. In response to stimulation with herpesvirus antigen, a population of T cells isolated from CSF cells from HSM mice (CSF-T cells) produced IL-4 into their culture fluids, although MCP-1 was not produced by CSF-T cells stimulated by this antigen. IL-4 production by CSF-T cells was markedly enhanced when they were stimulated with viral antigen in the presence of murine recombinant MCP-1 (rMCP-1). Furthermore, IL-4 was produced in naive splenic T cells cocultured with CSF-Mphi. These results indicate that the severity of HSM is influenced by MCP-1, which stimulates Th2 responses.

Rapid acid extrusion response triggered by alpha(1) adrenoceptor in CHO cells

1. Using a microphysiometer with synchronized valve switching, we investigated real-time acid extrusion from Chinese hamster ovary (CHO) cells in which human alpha(1) adrenoceptor (AR) is stably expressed, in response to noradrenaline (NA). 2. In the cells expressing alpha(1a) AR, the time course of extracellular acidification after stimulation had two phases; in the first phase it transiently reached a rate several times greater than the base rate with a peak at around 10 s, and in the second it increased to 2 times the base rate and reached a plateau in 2 min. Both phases showed a concentration-dependent increase of acidification rate in response to NA, but had distinct pEC(50) values; 5.6 for the transient phase and 7.2 for the steady phase. 3. In the cells expressing alpha(1b) AR, the transient phase was not detected but the steady phase was observed. The pEC(50) value was 7.1, although the magnitude of the response was much smaller than that with alpha(1a) AR. 4. Both 5-(N-ethyl-N-isopropyl)amiloride (EIPA) and HOE642 inhibited the acid extrusion response by either AR in a concentration-dependent manner. EIPA and HOE642 had high pIC(50) values (7.4 and 7.3, respectively) for inhibition of the transient phase response via alpha(1a) AR. In the inhibition of the steady phase response via alpha(1a) AR, both drugs revealed the presence of two components in the response; one had high pIC(50) values (8.1 and 8.2 for EIPA and HOE642, respectively) and the other had low pIC(50) values (5.6 and 6.0, respectively). In contrast, the steady phase response via alpha(1b) AR was inhibited by EIPA and HOE642 with low pIC(50) values (5.3 and 5.9, respectively). 5. As Ca2+ was depleted, the alpha(1a) AR-induced transient phase disappeared, while the steady phase was not affected. 6. These results suggest that alpha(1a) AR drives two acid extrusion systems in CHO cells upon stimulation; one elicits the transient response, which is largely mediated by an EIPA/HOE642-sensitive and Ca(2+)-dependent Na(+)-H(+) exchanger (NHE), presumably NHE1, and the other induces the steady acid extrusion that is mediated by NHE1 and another NHE which has low sensitivity to both EIPA and HOE642. alpha(1b) AR drives only the steady phase acid extrusion response, which is mainly mediated by NHEs other than NHE1.

Risk factors of hepatitis C virus-related liver cirrhosis in young adults: positive family history of liver disease and transporter associated with antigen processing 2(TAP2)*0201 Allele

The aim of this study was to clinically characterize young patients with hepatitis-C-related cirrhosis. We compared 27 patients with liver cirrhosis (Group LC) who were anti-HCV positive, aged 40 years or less at the time of diagnosis, with 323 consecutive patients with HCV-related chronic hepatitis (Group CH) matched for age and gender. Furthermore, Group LC was divided into two arbitrary groups (29-35 years, n = 8 /36-40 years, n = 19), based on the age of patients at the time of diagnosis of liver cirrhosis. Patients' characteristics and family history were investigated, and the frequency of transporter associated with antigen processing 2 (TAP2) was determined. A family history of liver disease was present in 40.7% of Group LC but in 18.0% of Group CH (P < 0.05). The younger the age of diagnosis of cirrhosis in Group LC, the higher the frequency of a positive family history (29-35 years, 87.5%; 36-40 years, 21.1%, P < 0.05). The frequency of TAP2*0201 was significantly higher in young adult patients with HCV-related liver cirrhosis than in HCV carriers with normal ALT (P < 0.05), and tended to be higher than in uninfected normal subjects (P = 0.05). The cumulative survival rate of cirrhosis patients with family history of liver diseases was significantly lower than that of cirrhosis patients without such history (P < 0.05). Our findings suggest that a positive family history of liver disease and TAP2*0201 polymorphism may be risk factors for HCV-related liver cirrhosis in young adults.

Herpes virus reactivation and gadolinium-enhanced magnetic resonance imaging in patients with facial palsy

OBJECTIVE

This study investigated whether magnetic resonance imaging (MRI) patterns were different between patients with Bell's palsy and those with herpetic facial palsy in whom varicella-zoster virus (VZV) or herpes simplex virus type 1 (HSV-1) reactivation had been confirmed by polymerase chain reaction (PCR) or serologic assay.

STUDY DESIGN

A retrospective study of 15 patients with acute peripheral facial palsy was performed to compare virologic tests and gadolinium (Gd)-enhanced MRI findings.

RESULTS

Ramsay Hunt syndrome was diagnosed in one patient. By use of virologic tests, zoster sine herpete (VZV reactivation without zoster) was diagnosed in four patients and HSV-1 reactivation in three. Bell's palsy was diagnosed in the remaining seven patients. No significant difference in the frequency of Gd-enhanced MRI was observed between herpetic facial palsy and Bell's palsy. However, in those patients who underwent MRI on the day viral reactivation was confirmed by PCR, Gd enhancement of the meatal fundus was observed infrequently. In addition, when MRI was performed within 10 days of the onset of palsy, Gd enhancement was not detected at the geniculate ganglion in any patients with herpetic facial palsy. By contrast, both the meatal fundus and the geniculate ganglion were enhanced in all patients with Bell's palsy, regardless of when MRI was performed with respect to the onset of palsy.

CONCLUSION

This study shows a difference in the pattern of Gd enhancement at the meatal fundus and the geniculate ganglion between patients with Bell's palsy and those with herpetic facial palsy. The results suggest that the meatal fundus or the geniculate ganglion may be affected first by virus reactivation in patients with herpetic facial palsy.

Evaluation of quantitative measurements of hepatitis C virus RNA to predict sustained response to interferon by genotype

Hepatitis C virus (HCV) virus load is one of the most important predictive factors for the outcome of interferon (IFN) therapy. Recent technological advances have allowed a more precise measurement of HCV load. However, the exact cutoff values that could be used to predict the outcome of IFN have not been established for each assay. Five recent quantitative assays were evaluated for the measurement of HCV (Amplicor monitor ver 1.0, Amplicor monitor ver 2.0 (GT), Amplicor monitor ver 2.0 (Cobas), Quantiplex branched DNA amplification (bDNA) ver 2.0 and HCV core protein level by enzyme immunosorbent assay) in 209 consecutive patients with chronic hepatitis C, who received IFN therapy. The results of the two second generation Amplicor monitor tests (GT and Cobas) showed the best correlation (r = 0.930), but the other tests also showed relatively good correlations (r = 0.646-0.925). Each method predicted the effect of IFN with comparable predictive efficacy, ranging from 77.0 to 80.8%. Receiver operating characteristic (ROC) curve analysis showed that Amplicor monitor ver 2.0 and bDNA ver 2.0 are superior in predicting the response in genotype 2a. The best cutoff value for predicting the response to IFN was different by genotype, which should be considered in selecting candidates for IFN treatment.

Neuroreceptor Bindings and Synaptic Activity in Visual System of Monocularly Enucleated Rat

PURPOSE

To study the changes in the distribution of postsynaptic benzodiazepine (BDZ) and presynaptic adenosine A(1) (AA(1)) receptors in the superior colliculus (SC) and visual cortex (VC) of rats following monocular enucleation.

METHODS

The right eyes of 6-week-old Long-Evans rats were enucleated and ex vivo autoradiography was performed on the SC and VC obtained at different times up to 8 weeks after the enucleation. [14C]deoxyglucose was used to detect glucose metabolism, and [11C]flumazenil and [1-methyl-(11)C]8-dicyclopropylmethyl-1-methyl-3-propylxanthine ([11C]MPDX) were used to map BDZ and AA(1) receptors, respectively. The receptor-specific binding for 11C was determined, and 11C and 14C activities were evaluated separately in the same tissue by a double tracing method.

RESULTS

The uptake of [14C]deoxyglucose in the SC was depressed immediately after enucleation and gradually recovered. The binding of [11C]flumazenil to BDZ receptors in the contralateral SC was increased at week 2, and then returned to the pre-enucleation levels. The uptake of [11C]MPDX by the AA(1) receptors in the contralateral SC decreased by about 67% on day 5 after enucleation and remained low thereafter. In the contralateral VC, the uptake of [14C]deoxyglucose decreased immediately after the enucleation followed by a gradual recovery, whereas the uptake of [11C]flumazenil and [11C]MPDX was not altered.

CONCLUSIONS

The axon degeneration related decrease of the AA(1) receptor density resulted in a transient up-regulation of postsynaptic BDZ receptor density in monocularly enucleated adult rats. These results suggest that these radioligands can be used to study the distribution of the postsynaptic BDZ and presynaptic AA(1) receptors in the visual system and can probably be applied to the human visual system for positron emission tomography.

Incidence of the appearance of the red color sign on esophageal varices and its predictive factors: long-term observations of 359 patients with cirrhosis

PURPOSE

The red color sign observed by endoscopic examination is a reliable predictive factor for variceal bleeding. The aim of this study was to calculate the incidence of the appearance of the red color sign and to evaluate its predictive factors.

METHODS

Endoscopic examination was repeatedly performed in 359 consecutive patients diagnosed as having liver cirrhosis with or without esophageal varices, during a median follow-up period of 2651 days.

RESULTS

The incidence of the appearance of the red color sign on esophageal varices at the end of the tenth year was compared among patients without varices (11.4%), those with small varices (45.4%), and those with mid-size varices (65.0%). The difference was significant (P < 0.0001). The number of varices (P = 0.0010), size of varices (P = 0.0064), platelet count (P = 0.0168), and alpha-fetoprotein level (P = 0.0207) were significantly correlated with the appearance of the red color sign, as estimated by the multivariate Cox hazard model. To exclude the influence of carcinogenesis, observation was stopped when hepatocellular carcinoma was discovered. Additive predictive factors with significance were: number of varices (P = 0.001), size of varices (P = 0.027), and platelet count (P = 0.0315).

CONCLUSIONS

Endoscopic signs of esophageal varices and platelet count were significant predictors for the appearance of the red color sign.

A rare aneurysmal bone cyst of the maxillary sinus: a case report

Aneurysmal bone cyst (ABC) is a non-neoplastic expansile bone lesion that is common in the long bones; only 2% occurs in the head and neck. We present a case of ABC in a 23-year-old male and describe the clinical and radiological features, histopathology and treatment. Magnetic resonance imaging (MRI) demonstrated multiple internal septations, cysts with fluid-fluid levels of varying intensity, and an intact rim of low-intensity signal completely surrounding the lesion. The tumor was removed by enucleation with resection of the lateral nasal cavity. Histopathologic diagnosis was ABC and fibrous dysplasia. We suggest that MRI is very useful for the diagnosis of ABC. ABC is thought to follow other lesions, and thus when treating ABC, it is important to determine whether any pre-existing lesion has preceded or not; in particular, if the lesion site is in the head and neck region.

Glycyrrhizin restores the impaired IL-12 production in thermally injured mice

Mice 6 days after thermal injury (TI-mice) did not respond to lipopolysaccharide (LPS) stimulation for production of serum interleukin 12 (IL-12; 2 h after LPS stimulation, <20 pg/ml in TI-mice; 1091+/-162 pg/ml in normal mice). However, 2 h after LPS stimulation, 1456+/-118 pg/ml of IL-12 were demonstrated in sera of TI-mice previously treated with a 10 mg/kg i.p. dose of glycyrrhizin (GR). IL-12 was not induced by LPS in sera of normal mice inoculated with burn-associated type 2 T cells (IL-4/IL-10-producing CD8+CD11b+TCRgamma/delta+T cells isolated from spleens of TI-mice). However, IL-12 production was induced by LPS in sera of these mice previously treated with GR or a mixture of monoclonal antibodies (mAbs) for type 2 cytokines. Also, IL-12 production was induced by LPS in TI-mice inoculated with CD4+T cells from spleens of GR-treated normal mice (GR-CD4+T cells, 5x10(6)cells/mouse). Since GR-CD4+T cells have been shown to be antagonistic cells against production of type 2 cytokines by burn-associated type 2 T cells, these results indicate that IL-12 unresponsiveness shown in TI-mice is recovered by GR through the regulation of burn-associated type 2 T cell responses.

A mechanism of interleukin-12 unresponsiveness associated with thermal injury

An unresponsive state for the production of interleukin-12 (IL-12) is commonly observed in animals and patients with severe thermal injuries. In the present study, the participation of corticosteroids, prostaglandin E(2) (PGE(2)), and type 2 cytokines, which appeared in association with thermal injury, on the burn-associated IL-12 unresponsiveness was studied. These substances have been described as inhibitors of IL-12 production. Less than 20 pg/ml serum IL-12 was produced in thermally injured mice (TI-mice) after stimulation with lipopolysaccharide (LPS), while 1037 pg/ml IL-12 was detected in sera of unburned mice equally stimulated with LPS. Almost complete restoration of the impaired IL-12 production was witnessed in TI-mice after treatment with soluble IL-4 receptor (50 ng/mouse, 2 h and 2 days after thermal injury). However, IL-12 was not induced by LPS stimulation in TI-mice treated with an inhibitor of PGE(2) (indomethacin, 0.1-5 mg/kg) or an inhibitor of corticosteroid production (ketoconazole, 10 mg/kg). LPS-stimulated IL-12 production was also impaired in normal mice inoculated with burn-associated type 2 T cells. In addition, in the presence of 1 microg/ml LPS, naive macrophages cocultured with burn-associated type 2 T cells did not produce IL-12 in their culture fluids, while IL-12 was produced by LPS-stimulated naive macrophages that were cocultured with naive splenic CD8(+) T cells. These results suggest that the IL-12-unresponsive state demonstrated in TI-mice is associated mainly with type 2 cytokines released from burn-associated type 2 T cells.

Long-term interferon therapy for 1 year or longer reduces the hepatocellular carcinogenesis rate in patients with liver cirrhosis caused by hepatitis C virus: a pilot study

BACKGROUND AND METHODS

In order to elucidate the influence of a long-term administration of interferon on the appearance rates of hepatocellular carcinoma (HCC) in hepatitis C virus (HCV)-related cirrhosis, we retrospectively analyzed 694 patients with cirrhosis. A total of 113 patients underwent interferon therapy, including 25 patients with a long-term administration of interferon for 1 year or more, and the other 581 patients received no antiviral drugs.

RESULTS

Crude cumulative appearance rates of HCC in the interferon and the untreated groups were 14.1, and 28.4% at the end of the 5th year, and 36.7 and 52.5% at the end of the 10th year, respectively (P = 0.0028). As there was a waiting time between diagnosis and treatment (median 2.0 months, average 21.3 months) in the treated group, Cox proportional hazard analysis using a time-dependent covariate was introduced to evaluate the anticarcinogenic effect of interferon. Although male sex, higher alpha-fetoprotein, older age, lower albumin concentration, and lower platelet count significantly increased the carcinogenesis rate, interferon was not a significant contributing factor to the carcinogenesis rate as a whole (hazard ratio = 0.83, P= 0.32). When the patients with interferon were divided into two groups according to therapy duration, long-term interferon therapy significantly decreased the hepatocellular carcinogenesis rate after an adjustment by significant covariates (hazard ratio = 0.28, P= 0.0048).

CONCLUSION

When interferon is administered for 12 months or longer, effective cancer prevention will be achieved, even in patients with HCV-related cirrhosis.

Twice-daily administration of interferon-beta for chronic hepatitis C is not superior to a once-daily regimen

PURPOSE

Although interferon (IFN) is commonly used for the treatment of chronic hepatitis C virus (HCV) infection, eradication of the virus occurs in only a small proportion of patients with genotype 1b and a high virus titer. Modified IFN therapies have been tried, with only limited benefit. Recently, the administration of IFN-beta twice per day has been reported to be more effective than the usual once-daily administration regimen. The aim of this study was to evaluate whether twice-daily IFN results in a sustained response in patients with chronic HCV infection with genotype 1b, and a high virus titer.

METHODS

Twenty patients with genotype 1b and high HCV RNA level (more than 1 MEq/ml by branched DNA probe assay) were randomly assigned to receive either twice-daily 3 MU of IFN beta (group A) or once-daily 6 MU of IFN-beta (group B) for 4 weeks. All patients received a further daily dose of 6 MU IFN-beta for 12 weeks, followed by IFN-alfa three times a week for 16 weeks.

RESULTS

Although a rapid fall in HCV RNA levels was noted in group A, a sustained response was observed in only one of nine patients in this group, and none of group B. Adverse effects of IFN were more frequent and pronounced in group A than in group B.

CONCLUSIONS

We conclude that further modification, which combines the early strong anti-viral effects of the twice-daily regimen with long-term sustained response, is necessary for effective therapy of HCV patients with genotype 1b and high HCV RNA levels.

Molecular and functional identification of large neutral amino acid transporters LAT1 and LAT2 and their pharmacological relevance at the blood-brain barrier

We present here the evidence of molecular and functional expression of LAT1 and LAT2, subunits of the large neutral amino acid transporter system L, in cultured brain capillary endothelial cells of the rat. By means of the RT-PCR method, transcripts of LAT1, LAT2 and heavy chain of 4F2 antigen (4F2hc) were detected in rat primary cultured brain capillary endothelial cells (BCECs) and immortalized subline, RBEC1. The uptake properties of RBEC1, such as [3H]leucine and L-[3H]DOPA uptake, were similar to those of primary cultured BCECs. So, RBEC1 may retain almost native properties of the large neutral amino acid uptake activities. [3H]Leucine uptake by RBEC1 showed two saturable components and the Km values of the high- and low-affinity components were 8.92+/-3.18 and 119+/-45 microM, respectively. The Km value of the high-affinity component agreed well with that of LAT1 and the amino acid transport selectivity of RBEC1 was similar to that of LAT1. Therefore, it is suggested that LAT1 is important at the blood-brain barrier of rats. Additionally, the Km value of the low-affinity component was similar to that of LAT2. These observations indicate that LAT1 and LAT2 are involved as transporters for large neutral amino acids at the blood-brain barrier. Additionally, we concluded that RBEC1 is useful as an in-vitro model for evaluation of the pharmacological relevance of system L at the blood-brain barrier.

Relationship between five-year histological outcome and serial changes in serum alanine aminotransferase in patients with biochemical and virological relapse after interferon treatment for chronic hepatitis C

OBJECTIVE

The aim of this study was to assess the correlation between serial changes in serum alanine aminotransferase (ALT) levels and histological outcome 5 years after treatment of patients with chronic hepatitis C with interferon (IFN).

METHODS

We retrospectively evaluated 61 consecutive patients who underwent two liver biopsies, just before and 5 years after a 6-month course of IFN therapy, and who showed a relapse after therapy. The extent of liver fibrosis was estimated using a scale with seven grades.

RESULTS

At the end of 6-month IFN therapy, 40 (65.6%) patients had normal serum ALT concentrations. However, 13 of the 40 patients relapsed within 6 months after IFN therapy. The average ALT during 5 years in 40 patients was less than or equal to 75 IU/l, while in the other 21 patients it was more than 75 IU/l. Among the 40 patients with a mean ALT less than 75 IU/l, 13 (33%) patients showed histological improvement, 26 (65%) showed no changes and only 1 patient (2%) showed worsening of liver fibrosis. On the other hand, among the 21 patients with a mean ALT of more than 75 IU/l, only 1 (5%) patient showed improvement, 8 (38%) showed no changes and 12 patients (57%) showed worsening of liver fibrosis.

CONCLUSION

There is a significant relationship between 5-year histological outcome and serial changes in serum ALT in patients with biochemical and virological relapse after IFN treatment for chronic hepatitis C.

Long-term increase of GluR2 alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor subunit in the dispersed dentate gyrus after intrahippocampal kainate injection in the mouse

Intrahippocampal injection of a subtoxic dose of kainate in mice has been shown to induce a dispersion of granule cells of the dentate gyrus, which is a characteristic morphological change often seen in human hippocampal sclerosis. In addition, it has been shown recently that such injections lead to recurrent hippocampal seizures and changes in glucose metabolism, which are reminiscent of temporal lobe epilepsy. Previous reports on human hippocampal sclerosis have shown an increase of the expression of the GluR2 alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate subunits in the dispersed granule cell somata. However, no such changes have been observed so far in animal models of epilepsy with hippocampal sclerosis. In this study, the expression of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor subunits was examined by immunohistochemistry following intrahippocampal injection of kainate in mice and rats. In mice, such injection induced a persistent increase of GluR2 immunoreactivity in the granule cells for up to 180 days. By contrast, GluR1 immunoreactivity was transiently increased during the first four days after the injection and progressively decreased thereafter. By contrast, intrahippocampal injection of kainate in rats did not result in granule cell dispersion and no changes in GluR1 immunoreactivity or GluR2 immunoreactivity were observed. These results show that, in addition to morphological, clinical and metabolical similarities, intrahippocampal injection of kainate results in a persistent increase of GluR2 associated with granule cell dispersion, as in human hippocampal sclerosis. These data suggest the existence of common mechanisms between granule cell dispersion and regulation of GluR2 subunits associated with hippocampal sclerosis.