Histopathologic impact of TT virus infection on the liver of type C chronic hepatitis and liver cirrhosis in Japan

The present investigation compared the histological findings in the liver of chronic hepatitis C patients who were or were not co-infected with TT virus (TTV) to determine the histological and clinical characteristics of TTV infection. One hundred eighty patients with chronic hepatitis or liver cirrhosis type C were included in this study. Serum samples were tested for the presence of TTV DNA by a nested polymerase chain reaction. The liver biopsy specimen of each patient was examined, and scores were assigned to indicate the severity of each of the following features: inflammatory cell infiltration in the periportal, parenchymal, and portal areas; fibrous stage; lymphoid reaction in the portal area; portal sclerotic change; perivenular fibrosis; pericellular fibrosis; damage of bile duct; and irregular regeneration of hepatocytes. Sixty-four (34.4%) of the 180 patients were positive for TTV DNA. The histological features of the liver and the blood biochemical parameters of the TTV DNA-positive and TTV DNA-negative patients, did not differ significantly except for the score of irregular regeneration (IR) of hepatocytes. Among those in the F4 stage of fibrosis, the score of IR of the TTV DNA-positive patients was significantly higher than that of the TTV DNA-negative patients. In conclusion, chronic TTV infection does not modify the biochemical features of chronic hepatitis type C patients. TTV may be a risk factor, however, for the development of hepatocellular carcinoma in patients with type C liver disease in the F4 stage.

Milrinone for the treatment of cerebral vasospasm after subarachnoid hemorrhage: report of seven cases

OBJECTIVE

The intra-arterial infusion of papaverine has been used for dilation of spastic cerebral vessels after aneurysmal subarachnoid hemorrhage, although its efficacy is controversial. Milrinone is an inotropic drug that dilates vessels by phosphodiesterase inhibition in a mechanism similar to that of papaverine. We examined the effects of intra-arterial and subsequent intravenous administration of milrinone on patients with symptomatic cerebral vasospasm.

METHODS

Seven patients with cerebral vasospasm were enrolled in this study. Milrinone was delivered intra-arterially via catheter at a rate of 0.25 mg/min. The total delivered dose was between 2.5 and 15 mg. Radiological measurement of the middle cerebral artery diameter and cerebral blood flow was carried out before and after arterial infusion. Intravenous treatment followed at 0.50 or 0.75 microg/kg/min for up to 2 weeks from the onset of subarachnoid hemorrhage.

RESULTS

Dilation of the vasospastic vessels occurred in all patients. The rate of cerebral blood flow was calculated in six patients and was increased in all. Subsequent intravenous infusion was effective in preventing a recurrence of symptomatic vasospasm in four of the seven patients.

CONCLUSION

It is suggested that milrinone was effective and safe for the treatment of cerebral vasospasm after subarachnoid hemorrhage in the patients in this series. Intra-arterial infusion with adjunctive intravenous infusion holds promise as a clinically advantageous treatment regimen.

Molecular characteristic-based epidemiology of hepatitis B, C, and E viruses and GB virus C/hepatitis G virus in Myanmar

We carried out a molecular characteristic-based epidemiological survey of various hepatitis viruses, including hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis E virus (HEV), and GB virus C (GBV-C)/hepatitis G virus (HGV), in Myanmar. The study population of 403 subjects consisted of 213 healthy individuals residing in the city of Yangon, Myanmar, and the surrounding suburbs and 190 liver disease patients (155 virus-related liver disease patients and 35 nonviral disease patients). The infection rates of the viruses among the 213 healthy subjects were as follows: 8% for HBV (16 patients), 2% for HCV (4 patients), and 8% for GBV-C/HGV (17 patients). In contrast, for 155 patients with acute hepatitis, chronic hepatitis, liver cirrhosis, or hepatocellular carcinoma, the infection rates were 30% for HBV (46 patients), 27% for HCV (41 patients), and 11% for GBV-C/HGV (17 patients). In the nonviral liver disease group of 35 patients with alcoholic liver disease, fatty liver, liver abscess, and biliary disease, the infection rates were 6% for HBV (2 patients), 20% for HCV (7 patients), and 26% for GBV-C/HGV (9 patients). The most common viral genotypes were type C of HBV (77%), type 3b of HCV (67%), and type 2 of GBV-C/HGV (67%). Moreover, testing for HEV among 371 subjects resulted in the detection of anti-HEV immunoglobulin G (IgG) in 117 patients (32%). The age prevalence of anti-HEV IgG was 3% for patients younger than 20 years and 30% or more for patients 20 years of age or older. Furthermore, a high prevalence of anti-HEV IgG (24%) was also found in swine living together with humans in Yangon. These results suggest that these hepatitis virus infections are widespread in Myanmar and have led to a high incidence of acute and chronic liver disease patients in the region.

Frequent presence of Helicobacter pylori genome in the saliva of patients with hyperemesis gravidarum

Recently, possible involvement of Helicobacter pylori (H. pylori) in hyperemesis gravidarum have been reported based on serological studies and the therapeutic effects of antibiotics. In this study, we examined for the presence of H. pylori genome [by (PCR) of saliva] in combination with serological techniques. Thirty-four patients with hyperemesis and 29 normal pregnant subjects were examined for serum anti-H. pylori IgG antibodies and PCR of saliva. By serum antibody test, 16 of 34 hyperemesis patients (47.5%) were positive for anti-H. pylori IgG antibody, while 6 of 29 control subjects (20.6%) were positive (chi2 p < 0.0005). PCR revealed positive H. pylori genome in 21 cases out of 34 hyperemesis (61.8%, 14 of 16 patients positive for H. pylori antibody and 7 of H. pylori-antibody-negative 18 patients) and 8 of 29 control subjects (27.6%) (chi2 p < 0.000001). We suggest chronic infection of H. pylori as one of the important factors on the pathogenesis of hyperemesis gravidarum even though it may not be the single cause of the disorder.

Immunoglobulin G and M hepatitis C virus core antibody (JCC.2) response in chimpanzees infected experimentally with hepatitis C virus

OBJECTIVE

To evaluate changes in serum immunoglobulin M (IgM) and G (IgG) hepatitis C virus (HCV) core antibodies after HCV infection in acute hepatitis C.

METHODS

Serum HCV RNA and IgM and IgG HCV core antibodies were investigated using sera sequentially sampled from three chimpanzees experimentally infected with HCV. Serum IgG HCV core antibody titer was measured using a JCC.2 enzyme-linked immunosorbent assay (ELISA) kit (Chemo-Sera-Therapeutic Research Center, Kumamoto, Japan). IgM core antibody titer was measured using horseradish peroxidase-labeled monoclonal anti-human IgM as the secondary antibody for the JCC.2 ELISA kit. Serum HCV RNA was detected using the 5' noncoding region as the primer according to the reverse transcriptase (RT) nested polymerase chain reaction (PCR) and competitive RT-PCR method.

RESULTS

IgM JCC.2 antibody was detected when alanine aminotransferase (ALT) peaked, showing the closest correlation with the changes in ALT. A period during which IgM JCC.2 antibody was positive but HCV RNA as determined by RT-nested PCR was negative was observed after the elevation of ALT level.

CONCLUSION

These results indicate the usefulness of detection of serum IgM JCC.2 antibody in making a definitive diagnosis of acute hepatitis C and the follow-up observation of hepatitis C.

Serum concentration of interferon-alpha: a comparison between once-a-day and twice-a-day administration

The aim of this study was to determine the possible mechanism of the antiviral activity of twice daily administration of interferon (IFN)-alpha for active hepatitis C and to evaluate serum concentrations of IFN-alpha with enzyme-linked immunosorbent assay (ELISA). Forty-seven patients with active hepatitis C received IFN-alpha intramuscularly for 24 weeks. They were divided into once-a-day and twice-a-day groups. Changes in serum IFN-alpha levels were assessed during the treatment period. Compared with twice-a-day treatment, the once-a-day group showed no increase in serum IFN-alpha at the end of daily treatment (p < 0.03). In contrast, one-third of the twice-a-day group showed increased IFN-alpha at the end of daily treatment (p < 0.02). In conclusion, measured with ELISA, twice-daily administration of IFN-alpha manifested prolonged elevation in serum levels when compared with once daily administration.

Roles of nocturnal melatonin and the pineal gland in modulation of water-immersion restraint stress-induced gastric mucosal lesions in rats

The roles of melatonin and the pineal gland in the circadian variation of water-immersion restraint stress-induced gastric mucosal lesions in rats were investigated. Fasted rats were subjected to water-immersion restraint stress during both the diurnal and nocturnal phases of a light:dark cycle. Pinealectomized and sham-operated rats were also subjected to water-immersion restraint stress at night. The lesion area after 4 hr of stress during the dark phase was significantly lower than in light-phase controls. Pinealectomy increased the lesion area in the dark phase, compared to the sham operation, but this effect was counteracted by intracisternal melatonin preadministration at a dose of 100 ng/rat. Melatonin concentrations in control rats during the light phase were significantly increased 4 hr after water-immersion restraint stress. In contrast, melatonin concentrations 4 hr after water-immersion restraint stress in the dark phase were significantly depressed compared with the control levels at the corresponding time. Melatonin levels after stress exposure were markedly decreased in pinealectomized rats as compared with sham-operated rats. These results suggest that circadian rhythm has an important role in the formation of stress-induced gastric mucosal lesions in rats and that melatonin responses to water-immersion restraint stress differ between day and night. The pineal gland modulates the stress response and melatonin contributes to gastric protection via a mechanism involving the central nervous system.

Direct screening of the IMP-1 metallo-beta-lactamase gene (blaIMP) from urine samples by polymerase chain reaction

BACKGROUND

As Gram-negative bacterial isolates producing plasmid-mediated IMP-1 metallo-beta-lactamase usually demonstrate resistance to various broad-spectrum beta-lactams, including cephamycins and carbapenems, transmission and proliferation of these microorganisms in clinical settings could become a clinical threat in the near future. According to previous studies by the same authors, IMP-1-producing strains are usually isolated from urine samples. Therefore, in this study, a polymerase chain reaction (PCR) was applied for direct screening of the IMP-1 metallo-beta-lactamase gene in urine samples.

METHOD

Urine samples were collected from 273 inpatients to whom various broad-spectrum beta-lactams, including carbapenems, had been administered in 57 hospitals in 1997. DNA templates for PCR analyses were prepared directly from 19 urine samples from which Serratia marcescens strains demonstrating high-level resistance (minimal inhibitory concentration > 128 microg/mL) to both ceftazidime and cefoperazone-sulbactam were later isolated.

RESULTS

The IMP-1 metallo-beta-lactamase gene (blaIMP)-specific 578 bp fragments were able to be amplified successfully in eight of the 19 samples. In the seven strains isolated from the eight samples, the presence of blaIMP was also detected by a DNA hybridization analysis. The lower limit of the PCR method was determined as 1 x 10(2) CFU of blaIMP-bearing bacterial cells per 1 mL of urine sample. No false positive result was found.

CONCLUSION

The PCR-aided direct screening of blaIMP is applicable to early recognition of IMP-1-producing bacteria in urine samples. This method would help to prevent nosocomial and interhospital transmission of this kind of hazardous bacteria, as well as the advancement of rigorous infection control.

Persistent TT virus infection does not contribute to the development of non-A to -G hepatocellular carcinoma. A case-control study of 19 patients in Japan

We tested the sera of patients with non-A, non-B, non-C, non-G (non-A to -G) hepatocellular carcinoma (HCC) for the presence of TT virus (TTV) DNA and clinicopathologically elucidated the relationship between TTV infection and hepatocarcinogenesis. The study cohort consisted of 19 patients with non-A to -G HCC. Detection of TTV DNA was performed by the nested polymerase chain reaction according to a previously published method. TTV DNA was detected in the sera of 9 (47.4%) of the 19 patients with non-A to -G HCC. The clinical background factors and blood biochemical parameters of the TTV-DNA-positive and -negative HCC patients did not significantly differ. Three TTV-DNA-positive and 2 TTV-DNA-negative patients underwent surgical resection of the HCC. The histological findings in the non-cancerous liver tissue of the TTV-DNA-positive and -negative patients did not significantly differ. In conclusion, TTV infection does not affect the features of non-A to -G HCC.

The clinical features of chronic hepatitis C are not affected by the coexistence of hepatitis B virus DNA in patients negative for hepatitis B surface antigen

Hepatitis B virus (HBV) DNA has been detected in the sera of hepatitis patients who are negative for hepatitis B surface antigen (HBsAg) by polymerase chain reaction (PCR). The purpose of the present study was to clarify the clinical characteristics of patients with chronic hepatitis C who are negative for serum HBsAg and positive for HBV DNA. The subjects included 49 patients with chronic hepatitis C who were negative for serum HBsAg and 119 blood donors who served as healthy controls. Serum samples were tested for the presence of HBV DNA by the nested PCR method. Serum HBV DNA was detected in 18 (37.7%) of the 49 chronic hepatitis C patients and in none (0%) of the 119 blood donors. Among the hepatitis C patients, HBV DNA was detected in 20.7% of those who were negative for all HBV-associated markers and in 57.1% of those who were positive for one or more HBV-associated marker. The HBV DNA-positive rate among those in each F stage did not significantly differ. The liver function parameters of the HBV DNA-positive and the HBV DNA-negative chronic hepatitis C patients did not significantly differ. These results suggest that hepatitis C virus is frequently coinfected with serum HBsAg-negative HBV, and that the incidence of HBV infection in blood donors is low. However, it is considered that HBsAg-negative HBV infection does not modify the blood biochemical features of chronic hepatitis C.

Irregular regeneration of hepatocytes is an important factor in the hepatocarcinogenesis of liver disease

The goal of this study was to assess the relationship between the degree of irregular regeneration of hepatocytes (IR) and the development of hepatocellular carcinoma (HCC). We examined the liver biopsy specimens from patients with chronic liver disease (CLD), and the noncancerous liver tissue in the surgically resected specimens from patients with HCC. Liver tissues were obtained from 18 patients with B-viral CLD, 38 with C-viral CLD, and 5 with nonB-nonC (NBNC)-CLD who underwent liver biopsy, and 24 patients with B-viral HCC, 67 with C-viral HCC, and 17 with NBNC-HCC who underwent surgical resection. The IR score of the noncancerous region of the liver of the HCC patients and that of the liver biopsy specimens of the CLD patients, were compared. Of the 108 samples of noncancerous liver tissue from the HCC patients, 70% showed an IR score of moderate or higher (IR = 3 or 4), and only 1.9% showed an IR score of none or minimal (IR = 0 or 1). The degree of IR of hepatocytes in the HCC patients was significantly more severe than that in the CLD patients in each etiological type of CLD. High IR may reflect the histologic expression of genetic instability, namely a carcinogenic state, although prospective studies are needed to determine its relationship to the risk for developing HCC.

Synthesis of variously oxidized abietane diterpenes and their antibacterial activities against MRSA and VRE

Variously oxidized 12 natural abietanes, 6,7-dehydroferruginol methyl ether (3), ferruginol (5), 11-hydroxy-12-oxo-7,9(11),13-abietatriene (7), royleanone (9), demethyl cryptojaponol (12), salvinolone (14), sugiol methyl ether (16), sugiol (17), 5,6-dehydrosugiol methyl ether (19), 5,6-dehydrosugiol (20), 6beta-hydroxyferruginol (23), and taxodione (25) were synthesized. Antimicrobial activities of synthesized phenolic diterpenes and their related compounds against MRSA and VRE were evaluated. Phenols (12-hydroxyabieta-8,11,13-trien-6-one 22 and 23), catechols (12 and 14) and taxodione 25 showed potent activity with 4-10 microg/mL of MIC against MRSA and 4-16 microg/mL of MIC against VRE. (-)-Ferruginol showed more potent activity than natural type (+)-ferruginol. Quinone methide 7 showed the most potent activity with 0.5-1 microg/mL of MIC against both MRSA and VRE.

Melatonin's gastroprotective and antistress roles involve both central and peripheral effects

Systemic administration of melatonin (5 to 20 mg/kg) has been reported to inhibit the induction of acute gastric mucosal lesions by stress or ischemia-reperfusion in rats. We recently demonstrated that intracisternal (i.c.) melatonin at low doses (1 to 100 ng) dose-dependently decreased acid and pepsin outputs in rats. The aim of the present study was to further investigate the peripheral and central roles of melatonin in gastric mucosal defense. Using a radioimmunoassay, we measured melatonin concentrations in the plasma and cerebrospinal fluid (CSF) of the cisterna magna in rats subjected to water immersion restraint stress and given intraperitoneal (i.p.) or i.c. injection of melatonin. Water immersion restraint stress was followed by a significant duration-related increase in peripheral plasma melatonin levels; the stress similarly produced a time-dependent increase in the extent of gastric mucosal lesions. Administration of melatonin (1 or 10 mg/kg, i.p., or 100 ng/10 microl, i.c.) significantly reduced the extent of stress-induced gastric damage, by 46%, 67%, and 54%, respectively. The effective i.c. dose of melatonin was at least 10,000-fold smaller than the effective i.p. dose. Melatonin levels in plasma and CSF after the i.p. injection of melatonin at 10 mg/kg were dramatically higher than those after the i.c. injection of vehicle or 100 ng of melatonin. Our results suggest that the peripheral gastroprotective action of melatonin should be investigated with due regard to these central effects.

Photorefractive multiple quantum wells at 1064 nm

We have fabricated photorefractive InGaAs/GaAs multiple quantum wells that are sensitive at wavelengths near 1.06 mum for what is believed to be the first time. We have measured four-wave-mixing diffraction efficiency, using a Nd:YAG laser. A maximum diffraction efficiency of 7 x 10(-4) and a cutoff grating period of ~2 mum are obtained.

Survival activity of troglitazone in rat motoneurones

Troglitazone (TGZ), an antidiabetic drug that improves insulin-resistance in the peripheral tissues, was tested for neurotrophic activity in motoneurones and other neurones in culture. In rat motoneurones, TGZ had a remarkable effect on survival, which was comparable or superior to that of brain-derived neurotrophic factor, a known potent neurotrophic factor for rat motoneurones. However, TGZ did not promote the survival of sensory, sympathetic, septal or hippocampal neurones. The effect of TGZ on motoneurones was additive to that of insulin-like growth factor-I and both activities were inhibited by phosphatidylinositol 3-kinase (PI3-kinase) inhibitors, wortmannin and LY294002, suggesting the involvement of the activation of PI3-kinase in the activity of TGZ. Pioglitazone, another antidiabetic drug structurally similar to TGZ, did not show any activity, indicating that the agonistic activity of TGZ for peroxisome proliferator-activated receptor-gamma is not involved in the survival activity. Chromanol, an antioxidant moiety of TGZ, showed little or no survival activity. These results indicate specific neurotrophic activity of TGZ for motoneurones through the activation of PI3-kinase and support the applicability of TGZ for the treatment of motor neurone diseases such as amyotrophic lateral sclerosis.

Carotid stenting with the use of wallstent

SUMMARY

We performed carotid stenting with Wallstent for 22 cases. The mean stenosis was 74.3 +/- 11.2% before stenting and 14.2 +/- 8.8% after stenting. The technical success (< 40% residual stenosis) was 100%. We experienced 2 embolic complications (one TIA and one minor stroke). Permanent neurological deficits were not encountered in all the patients (0%). Restenosis was observed in 2 cases (12.5%). The both lesions revealed intimal hyperplasia on intravascular ultrasound (IVUS). MRI diffusion weighted study showed that distal embolism happened more often (46.2%) than we expected although most of them were asymptomatic.We must wait for the long term result to conclude that carotid stenting has become one of the treatment modalities.

Full-length nucleotide sequence of a simian TT virus isolate obtained from a chimpanzee: evidence for a new TT virus-like species

Recently, we identified TT virus (TTV) isolates from nonhuman primates and named them simian TTV (s-TTV). To characterize the genomic structure of these isolates in more detail, the full-length nucleotide sequence of the s-TTV isolate (designated s-TTV CH65-1), recovered from a chimpanzee born in West Africa, was amplified by nested PCR with inverted primers deduced from the untranslated region of s-TTV DNA. CH65-1 was composed of 3899 nucleotides (nt) and had two open reading frames (ORF) spanning 2295 nt (ORF1) and 402 nt (ORF2). The sequence had only 52.3% similarity to the prototype TA278 human isolate. Phylogenetic analysis demonstrated that CH65-1 was distinct from the human TTV isolates. These results suggested that s-TTV may represent a new TTV-like viral species or genus.

Hepatitis C virus core protein activates the MAPK/ERK cascade synergistically with tumor promoter TPA, but not with epidermal growth factor or transforming growth factor alpha

Persistent hepatitis C virus (HCV) infection is associated with the development of human hepatocellular carcinoma (HCC), although the mechanism of HCV-related hepatocarcinogenesis remains unclear. Recently, however, the close relationships between the development of HCC and the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated protein kinase (ERK) cascade have been described. In the present study, we investigated the effects of HCV core protein on this MAPK/ERK cascade. HCV core protein significantly activated the MAPK/ERK cascade, including Elk1. We also examined whether HCV core protein acted synergistically along with hepatocyte mitogen-mediated MAPK/ERK activation. Interestingly, Elk-1 activities were further enhanced by the tumor promoter, 12-O-tetradecanoyl phorbol 13-acetate (TPA), but not by hepatocyte mitogens (epidermal growth factor [EGF] and transforming growth factor alpha [TGF-alpha]) in NIH3T3 cells and HepG2 cells expressing HCV core protein. Moreover, the MAPK/ERK activation by HCV core protein was blocked in the presence of the specific MEK1 inhibitor, PD98059. These results indicate that ERK activation by HCV core protein may be independent of hepatocyte mitogen-mediated signaling but synergistic with TPA, and HCV core protein may function at MEK1 or farther upstream of that component.

Hepatitis G virus coinfection influences the liver histology of patients with chronic hepatitis C

AIMS/BACKGROUND

The present investigation compared the histological features of the liver of chronic hepatitis C patients who are or are not coinfected with hepatitis G virus (HGV) to determine the histological and clinical characteristics of HGV infection.

SUBJECTS AND METHODS

This study included 194 patients with chronic hepatitis C who visited our institution between 1993 and 1995. Detection of serum HGV RNA was performed by nested reverse transcription-polymerase chain reaction. Scores were assigned to indicate the severity of each of the following features on the liver biopsy of a patient: inflammatory cell infiltration in the periportal, parenchymal, and portal area; fibrous stage; lymphoid aggregates in the portal area; portal sclerotic change; perivenular fibrosis; pericellular fibrosis; bile duct damage; bridging necrosis; and irregular regeneration of hepatocytes (IR).

RESULTS

HGV RNA was detected in the sera of 18 (9.3%) of the 194 patients. The histological features of the HGV RNA-positive patients show significantly more severe bile duct damage, perivenular fibrosis, pericellular fibrosis and IR than the liver of the HGV RNA-negative patients. The biochemical results in the two groups did not significantly differ.

CONCLUSION

Our data suggest that chronic HGV coinfection worsens the histological features of liver disease.

[Stenting for intracranial internal carotid artery stenosis with the use of a coronary stent: a case report]

A 61-year-old man was admitted to our hospital for mild left hemiparesis and speech disturbance. An initial angiogram revealed occlusion of the right internal carotid artery (ICA) but with sufficient collateral flow by compensated the contralateral carotid artery. Severe stenosis (70%) in the intracavernous (C4-5) portion was identified in the left ICA. Cerebral blood flow was remarkably decreased in both hemispheres. The patient's hemiparesis fluctuated according to the systemic blood pressure in such a manner that induced hypertension therapy was mandatory. On the 19th hospital day, we performed stenting of the left ICA stenosis using a coronary stent. A flexible coronary stent, NIR PRIMO stent 3.0 mm/16 mm (SCIMED, Boston Scientific) was deployed after the predilatation (2.5 mm/10 atm). The initial 70% stenosis was reduced to 6% after the postdilatation (3.75 mm/8 atm). The neurological status was stable after the procedure and we stopped the induced hypertension therapy the next day. We consider that intracranial artery stenting will be a common therapeutic modality in the near future.

Molecular analysis of hepatitis D virus infection in Miyako Island, a small Japanese island

The present investigation attempted to determine the exact prevalence of hepatitis D virus (HDV) infection among inhabitants of Miyako Island (a remote island in the Okinawa Prefecture) and the molecular characteristics of the HDV genome that was isolated. Among the 4728 inhabitants, 375 (7.9%) were hepatitis B surface antigen (HBsAg) positive. Antibody to HDV (anti-HDV) was present in 32 (8. 5%) of these 375 subjects, and liver function tests were normal in most subjects. The presence of HDV RNA was analysed by nested polymerase chain reaction (PCR). Thirteen out of the 32 anti-HDV antibody-positive subjects were HDV RNA positive. Thus, 3.5% of HBsAg-positive subjects on Miyako Island were HDV RNA positive. Among the HDV RNA-positive subjects, liver function tests were within normal limits or were mildly abnormal. Nucleotide sequence analysis revealed that the HDV genomes on Miyako Island were similar to the Japanese and Taiwan isolates of HDV genotype II. Taiwan is geographically close to Miyako Island. Even though the races are different, a geographical factor was revealed to be significant with regard to HDV infection, which was spread in a closed environment.

Molecular evidence of natural hybridization between Fasciola hepatica and F. gigantica

Nucleotide sequences of two regions, cytochrome c-oxidase subunit 1 (CO1) and NADH dehydrogenase subunit 1 (ND1) of the mitochondrial DNA and two regions, internal-transcribed spacer 2 (ITS2) and the D2 region in the 28S rDNA (28S) of the nuclear DNA were obtained from five Korean worms of the genus Fasciola in order to elucidate their taxonomic status. The CO1 and ND1 regions are all monomorphic in the Korean worms and similar to those of F. gigantica. On the other hand, the ITS2 and D2 regions were found to be polymorphic; that is, out of five worms, two possessed a F. gigantica-type sequence, one, a F. hepatica-type sequence and two possessed sequences of both types indicating an existence of different alleles at the loci. It should be noted that these variations of the ITS2 and D2 regions co-occur at the same individual worms. This was confirmed by sequencing five to six cloned PCR products for each worm. The present study strongly suggests interspecific cross-hybridization between the two species coexisting in Korea.