Seroepidemiology of hepatitis C virus infection in Japan and HCV infection in haemodialysis patients

Since January 1990, Japanese Red Cross Blood Centres have introduced hepatitis C virus screening with a first-generation ELISA. From April to December 1992, approximately 0.98% among 10,905,489 blood donations screened by a second-generation assay were anti-HCV-positive in all Japan. Seropositivity of anti-HCV increased with the age and serum transaminase value in both sexes. In blood donors having a history of transfusion, the anti-HCV reactive rate was 7.4%. The results of the study made by the Japanese Red Cross Non-A, Non-B Hepatitis Research Group show the effectiveness of implementation of HCV screening to prevent posttransfusion hepatitis. Consecutive haemodialysis patients with chronic renal failure are at risk for infection by a variety of blood-borne agents transmitted within dialysis units. Because of their immunocompromised state, they frequently also have an unusual susceptibility to a variety of nosocomial infections, such as HBV, HCV, and HTLV-I. We tested the prevalence of anti-HCV in 1423 (848 males and 575 females) haemodialysis patients from 18 hospitals in Kumamoto Prefecture, Japan, using the Ortho first generation anti-HCV screening assay. There were 316 patients (22.2%) positive for HCV antibodies. The second-generation test was positive in most haemodialysis patients who were reactive to the first-generation assay. The prevalence of HCV infection increased with the duration of haemodialysis, yet there was a high frequency of HCV seropositivity even without blood transfusion. Acquisition of HCV in dialysis patients could be explained by HCV infection within the unit other than by blood (all haemodialysis are done with disposable kits, syringes, and needles), by secondary HCV infection after the immunodeficiency of haemodialysis, or by HCV infection of the kidney or glomerular deposition of immune HCV/anti-HCV complexes leading to chronic renal failure (as with HBV infection of the liver and kidney.

Establishment of a human small cell lung cancer cell line producing a large amount of anti-diuretic hormone

A new cancer cell line (Lu-165) producing a large amount of anti-diuretic hormone (ADH, 2.8 micrograms/g protein) was established from a 50-year-old small cell lung cancer patient presenting with a syndrome of inappropriate anti-diuretic hormone secretion. These cells grew well in serum-supplemented medium and during more than 100 passages they continued producing a large amount of this hormone. This cell line will be a useful tool for studies of the biochemistry and pathology of ADH-producing cancer.

Hepatitis C virus particle detected by immunoelectron microscopic study

To clarify the morphology of hepatitis C virus (HCV), an indirect immunogold electron microscopic study was carried out on two plasma samples with high HCV RNA titres using polyclonal and monoclonal antibodies specific to the putative HCV envelope protein. Spherical virus-like particles, 55 to 65 nm in diameter with spike-like projections, were found in 1.14 to 1.16 g/ml fractions after sucrose density gradient centrifugation. These particles were found only in HCV-infected blood donors and had morphological features similar to those of flaviviruses. Moreover, these particles specifically reacted with the polyclonal and monoclonal antibodies to the putative HCV envelope protein. This is the first known report in which the morphology of the HCV particle is clearly shown.

[Experimental study of differentiation between tumor and inflammation using MR imaging: correlation between VX2 tumors and croton oil induced inflammation in the rabbit's femoral muscle]

We evaluated the various Magnetic Resonance (MR) sequences for differentiation between tumors and inflammation. Experimental models of rabbit's tumors (VX2) and inflammation induced by croton oil in the femoral muscle were used for this evaluation. Both types of lesions presented a high intensity area on T2-weighted and heavy T2-weighted images. An inflammatory lesion was revealed with iso-/low intensity area and tumors were defined as high signal lesions on Sinc saturation fat suppression T1-weighted, standard T1-weighted and fat suppression T1-weighted images by the 3 Point dixon method. T1, T2 values of tumor and inflammatory lesions were also measured. The T1 value of the tumors was 1186 +/- 58 msec (n = 5) and that of the inflammatory lesion was 1097 +/- 40 msec (n = 3). The T2 value of the tumors was 71 +/- 13 msec (n = 5) and that of the inflammatory lesions was 70 +/- 5.5 msec (n = 3). There were no significant differences between both the T1 and T2 values. Calculated relative proton density was 0.69 +/- 0.14 (n = 4) in the tumors, and 0.42 +/- 0.12 (n = 3) in the inflammatory lesions. A statistical difference (p < 0.05) was found in both value. These results suggest that a T2-weighted image is not useful for differentiation between tumors and inflammation, and a T1-weighted image might be useful for such differentiation. This phenomenon is related to the difference of the proton density.

Significance of specific antibody assay for genotyping of hepatitis C virus

Group I and II hepatitis C virus genotypes were determined by a newly developed serological genotyping assay. This assay detected antibodies against group-specific recombinant proteins in the putative NS4 protein region (amino acid no. 1676-1760) by an enzyme-linked immunosorbent assay. This region of the hepatitis C virus peptide has many group-specific amino acids; fewer than 50% of these amino acids are identical between groups I and II. Genotypes determined by the serological genotyping assay were compared with those determined by a method in which the polymerase chain reaction was used in 91 chronic hepatitis patients. The group-specific polymerase chain reaction was performed within the genome region corresponding to the putative NS5 protein, where the group II hepatitis C virus genome is 57 nucleotides longer than that of group I. Among 91 chronic hepatitis C patients who had positive results in the second-generation hepatitis C virus antibody (core and NS3 region) assay, hepatitis C virus RNA was detected in 80 patients by polymerase chain reaction in the 5' untranslated region and in 78 patients by this group-specific polymerase chain reaction. As a result, in 76 of 91 patients (84%) genotypes determined by the serological genotyping assay showed complete agreement with those determined by the group-specific polymerase chain reaction, and none of the patients revealed a group opposite to that of hepatitis C virus genotype. The detection rate of the serological genotyping assay (89 of 91; 98%) was even higher than that of the polymerase chain reaction assay (78 of 91; 86%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Stereochemistry of benzanilides and N-methylbenzanilides]

Conformations of benzanilide , N-methylbenzanilide and those with a methyl group(s) ortho to the amide bond in solution and in the crystal have been studied. N-Methylbenzanilide exists in cis-amide (E) form in the crystal. In CDCl3 solution, cis-amide form is also predominant (99%), while benzanilide exists in trans-amide (Z) form in the crystal and in solution. In the crystal, all the methyl-substituted benzanilides exist in trans-amide conformation and the introduction of an ortho-methyl group(s) makes the interplanar angles of the aromatic rings and the amide group (Aramide) larger. N-Methylbenzanilides exist in cis form in the crystal except the compound which has four methyl groups ortho to the amide bond. For the N-methylbenzanilides, the effects of introduction of one or two ortho-methyl groups on the dihedral angles of Ar-amide are smaller than that for the secondary benzanilides. In solution, benzanilides exist exclusively in trans conformation except for the compound 12 which has a minor cis conformer (3%) in CDCl3, whereas N-methylbenzanilides exist in equilibrium between the major cis-form and the minor trans-form. The tetramethyl derivative exists in trans conformation in solution as observed in the crystal. For N-methylbenzanilides, an introduction of a methyl group(s) ortho to the amide bond seems to destabilize the cis-amide conformation in solution, resulting in an increased ratio of the trans-amide conformation.

Production of endothelin-1 and thrombomodulin by human pancreatic cancer cells

Analysis of bioactive substances produced by cancer cells is one approach to understanding the biological features of human cancer. One of these bioactive substances is endothelin (ET)-1, a peptide with potent vasoconstrictive activity produced by vascular endothelial cells. We have previously reported the production of ET-1 by several types of human cancer, especially pancreatic cancer cells. To elucidate whether these cancer cells might share biological characteristics with vascular endothelial cells, we investigated the production of three ET isoforms in pancreatic cancer cells, using a specific radioimmunoassay. Further, we also investigated whether these cells produce thrombomodulin (TM), another product of endothelial cells functioning as a modulator of procoagulant activity. ET-1 was detected in 11 of 12 pancreatic cancer cell lines (92%) while ET-2 and ET-3 were detectable in only one cell line. Gel filtration analysis confirmed the presence of ET-1. Moreover, TM was detected in the cell lysates of 11 of the 12 cell lines (92%) and it was released into the culture medium in the majority (58%) of these cell lines. TM mRNA was also detected in these cells. In addition, TM was demonstrated immunocytochemically along the cell surface. These results suggest that pancreatic cancer cells share two characteristics with endothelial cells: the production of ET-1 and TM.

[Xenon-133 rCBF SPECT by newly designed bolus inhalation method]

Single photon emission computed tomography (SPECT) with 133Xe gas inhalation method enables measurement of regional cerebral blood flow (rCBF) quantitatively. But this method is inferior to the method with 99mTc-HMPAO or 123I-IMP in the quality of images. Efficient administration of 133Xe gas more than usual is supposed to improve quality of SPECT images. In this study we designed bolus inhalation method, a new method to efficiently administer 133Xe gas of usual dose (1,850 MBq), and examined its fundamental aspects and clinical feasibility. The method was initiated by bolus administration of 133Xe gas synchronously in inspiration phase via a small tube connected to a mouthpiece and was followed by steady breathing of the gas in a closed circuit with a spiro-bag. Introduction of this method provided almost twofold increase in count ratio at the head in comparison with a conventional inhalation method. Consequently, considerable improvement in the quality of rCBF images was achieved by optimization of a reconstruction filter of SPECT.

Intracranial vertebral artery dissection in Wallenberg syndrome

PURPOSE

To assess the prevalence of vertebral artery dissection in Wallenberg syndrome.

METHODS

Sixteen patients (12 men, 4 women; mean age at ictus, 51.6 years) with symptoms of Wallenberg syndrome and an infarction demonstrated in the lateral medulla on MR were reviewed retrospectively. The study items were as follows: (a) headache as clinical signs, in particular, occipitalgia and/or posterior neck pain at ictus; (b) MR findings, such as intramural hematoma on T1-weighted images, intimal flap on T2-weighted images, and double lumen on three-dimensional spoiled gradient-recalled acquisition in a steady state with gadopentetate dimeglumine; (c) direct angiographic findings of dissection, such as double lumen, intimal flap, and resolution of stenosis on follow-up angiography; and (d) indirect angiographic findings of dissection (such as string sign, pearl and string sign, tapered narrowing, etc). Patients were classified as definite dissection if they had reliable MR findings (ie, intramural hematoma, intimal flap, and enhancement of wall and septum) and/or direct angiographic findings; as probable dissection if they showed both headache and suspected findings (ie, double lumen on 3-D spoiled gradient-recalled acquisition in a steady state or indirect angiographic findings); and as suspected dissection in those with only headache or suspected findings.

RESULTS

Seven of 16 patients were classified as definite dissection, 3 as probable dissection, and 3 as suspected dissection. Four patients were considered to have bilateral vertebral artery dissection on the basis of MR findings.

CONCLUSIONS

Vertebral artery dissection is an important cause of Wallenberg syndrome.

[S antigen in retinas of royal college of surgeons rats: time course and retinal pigment epithelium transplant study]

Retinas of Royal College of Surgeons (RCS) rats were investigated immunocytochemically for the distribution of S antigen prior to and during the retinal disease process. RCS retinas onto which retinal pigment epithelium (RPE) had been transplanted were also immunostained with antibody for S antigen. At P2, weak immunostaining for S antigen was seen in neuroepithelium. At P22, the staining pattern outlined the entire photoreceptor layer. At P30, at the beginning of retinal degeneration, immunostaining for S antigen was considerably reduced in the degenerating photoreceptor outer segment. In the RCS retina at P90, immunostaining for S antigen was completely lost. However, retinas with transplanted RPE showed preserved immunocytochemical staining for S antigen at this late stage. These results suggest a loss of production of S antigen in degenerated retinal tissue, and that RPE transplantation helps to preserve S antigen in the RCS rat retina.

[Evaluation of bactericidal activity of arbekacin in mixed culture with MRSA and Pseudomonas aeruginosa using an in vitro pharmacokinetic simulation system]

The bactericidal activities of arbekacin (ABK), vancomycin (VCM), gentamicin (GM) and netilmicin (NTL) in mixed culture with Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa were examined using an in vitro computer programmed pharmacokinetic simulation system and also the protective effect of these agents on systemic infection in neutropenic mice was examined. In a mixed culture of S. aureus No. 235 (MRSA) and P. aeruginosa E7, ABK showed a strong bactericidal activity and an inhibition of regrowth against both bacteria, and GM and NTL showed similar effects. On the other hand, VCM showed a bactericidal activity against S. aureus No. 235, but not against P. aeruginosa. In the protective study, ABK was evidently more effective than GM, NTL or VCM against a systemic mixed infection of mice with S. aureus No. 235 and P. aeruginosa E7. In brief, the ED50 values of ABK, VCM, GM and NTL were 19.5, > 100, 40.5 and 45.2 mg/kg, respectively.

Neurotrophin-3 gene polymorphism associated with schizophrenia

The recent possible neurodevelopmental etiology of schizophrenia makes the neurotrophin-3 (NT-3) gene an interesting candidate locus. We studied the allelic distributions of dinucleotide repeat polymorphism at the NT-3 gene locus in 70 patients with schizophrenia and in 70 controls. A highly significant difference between the two groups was observed at the allele A3. Even Bonferroni's correction was used, the difference was still significant. Individuals with homozygous or heterozygous for the allele A3 had a 2.4-fold increased risk of schizophrenia. Determination of NT-3 genotype may help to identify those at greater risk of schizophrenia. Furthermore, this finding supports evidence implicating neurodevelopmental deficit in the pathogenesis of this disorder.

KF17837 ((E)-8-(3,4-dimethoxystyryl)-1,3-dipropyl-7-methylxanthine), a potent and selective adenosine A2 receptor antagonist

8-(3,4-Dimethoxystryryl)-1,3-dipropyl-7-methylxanthine exhibited high affinity and selectivity for adenosine A2A receptors in binding assay using rat striatal A2A receptors labeled with [3H]2-[p-(2-carboxyethyl)-phenethylamino]-5'-N-ethylcarboxamido adenosin e (CGS21680). The affinity was stereo selective: the E isomer, KF17837, showed a Ki value of 1.0 +/- 0.057 nM for the A2A receptors, whereas the Z isomer showed much lower affinity. KF17837 had 62-fold selectivity for the A2A receptors versus rat forebrain A1 receptors labeled with [3H]N6-cyclohexyladenosine (CHA). KF17837 was rapidly photoisomerized to form a stable equilibrium mixture (18% E - 82% Z), KF17837S, which showed Ki values of 7.9 +/- 0.055 nM and 390 +/- 68 nM for the A2A and A1 receptors, respectively. The inhibition type was competitive for [3H]CGS21680 binding. In rat pheochromocytoma PC12 cells KF17837S antagonized cAMP accumulation induced by 1 microM CGS21680 via the A2A receptors, with an IC50 value of 53 +/- 10 nM. cAMP accumulation induced by 10 microM 5'-N-ethylcarboxamidoadenosine via the A2B receptors in Jurkat cells (human T-cell line) was inhibited by KF17837S with an IC50 value of 1500 +/- 290 nM. These results indicate that KF17837S (and hence KF17837) is a highly potent and selective adenosine A2A receptor antagonist.

In vitro and in vivo antibacterial activities of KRM-1648 and KRM-1657, new rifamycin derivatives

The in vitro and in vivo antibacterial activities of the new rifamycin derivatives KRM-1648 and KRM-1657 were compared with those of rifampin. Rifabutin, ciprofloxacin, and clarithromycin were also tested for reference. The respective MICs of KRM-1648 and KRM-1657 for 90% of the strains tested (MIC90S) were 0.016 and 0.0078 microgram/ml, respectively, for methicillin-susceptible Staphylococcus aureus, 0.016 and 0.0039 microgram/ml, respectively, for methicillin-resistant S. aureus, and 0.0625 and 0.016 microgram/ml, respectively, for methicillin- and quinolone-resistant S. aureus. These MIC90S of KRM-1657 were equal to or 2- to 64-fold lower than those of rifampin. KRM-1648 and KRM-1657 with MIC90S of between 0.002 and 0.078 microgram/ml were 2- to 128-fold more active than rifampin against Staphylococcus epidermidis and Streptococcus species, including Streptococcus pneumoniae and Streptococcus pyogenes. The MIC90S of KRM-1657 for Haemophilus influenzae and Neisseria gonorrhoeae were 0.25 and 0.1 microgram/ml, respectively; KRM-1657 was almost as active as rifampin and was 8- to 16-fold more active than KRM-1648 against these strains. The frequency of occurrence of spontaneous mutations to resistance to KRM-1648 and KRM-1657 was equal to that to rifampin. Against systemic infection with S. aureus in mice, the efficacies of KRM-1648 and KRM-1657 were comparable to that of rifampin.

A modified nonradioactive method for northern blot analysis

In this report we use several previously described methods, in novel combination, to establish a sensitive and flexible nonradioactive method. First, we prepared single-stranded digoxigenin-labeled probes using a high-efficiency polymerase chain reaction (PCR) method (4). For detection of RNA, blots were hybridized with probes containing digoxigenin and then incubated with alkaline phosphatase-conjugated anti-digoxigenin antibody. Bound probe was rapidly detected with X-ray film using localized light emission from the reaction of alkaline phosphatase with lumigen-paraphenylenediamine substrate (5). This method allows flexibility in probe sequence selection, independent of restriction enzyme site location, and it works well with small probes. This approach allows sensitive differential analysis of closely related members of a gene family.

Conformational stability of alpha-lactalbumin missing a peptide bond between Asp66 and Pro67

The peptide bond between Asp66-Pro67 of alpha-lactalbumin was cleaved with formic acid (cleaved alpha-lactalbumin). Secondary structural changes of the cleaved alpha-lactalbumin, in which the two separated polypeptides were joined by disulfide bridges, were examined in solutions of sodium dodecyl sulfate (SDS), urea, and guanidine hydrochloride. The structural changes of the cleaved alpha-lactalbumin were compared with those of the intact protein. The relative proportions of secondary structures were determined by curve fitting of the circular dichroism. The cleaved alpha-lactalbumin contained 29% alpha-helical structure as against 34% for the intact protein. Some helices of the cleaved alpha-lactalbumin which had been disrupted by the cleavage appeared to be reformed upon the addition of SDS of very low concentration (0.5 mM). In the SDS solution, the helicities of both the intact and cleaved proteins increased, attaining 44% at 4 mM SDS. On the other hand, the helical structures of the cleaved alpha-lactalbumin began to be disrupted at low concentrations of guanidine hydrochloride and urea compared with that of the intact protein. However, no difference was observed in the thermal denaturations of the intact and cleaved proteins, except for the difference in the original helicities. The helicities of both proteins decreased with an increase of temperature up to 65 degrees C and recovered upon cooling.

Adaptation of hepatitis C virus for persistent infection in patients with acute hepatitis

Nucleotide sequencing was used to analyze amino acid substitutions in the putative envelope 1 (E1) and envelope 2/nonstructural 1 (E2/NS1) regions of hepatitis C virus (HCV) to clarify a viral mechanism of persistent infection in three patients with acute hepatitis C who developed chronic hepatitis and two patients with chronic hepatitis. The HCV RNA titer in serum decreased markedly after the onset of acute hepatitis and then re-elevated. During this period, the substitution rate in the E2/NS1 region (especially in the hypervariable region located in the N-terminus) was significantly higher in patients with acute hepatitis than in patients with chronic hepatitis (P < 0.05). When patients with acute hepatitis C became persistent HCV carriers, the substitution rate decreased to the level seen in patients with chronic hepatitis. The amino acid substitution rate in the E1 region in the acute phase was similar to that found in the chronic HCV carrier state. These observations suggest that rapid substitution of the amino acid sequence in the hypervariable region of the E2/NS1 region may be one of the mechanisms of persistent HCV infection.

[Diagnostic value of glass microfibre-based basophil histamine release test in food allergic children. Comparison with specific IgE antibody and skin scratch test]

We evaluated the diagnostic value of the glass microfibre-based histamine release test (HRT), which allows measurements to be performed using small amounts of whole blood, in 50 children with food allergy case histories. The patients were evaluated by radioallergosorbent tests (RAST), skin scratch tests (ST) and food challenge tests. Of the 50 patients, 39 had a confirmed clinical diagnosis of food allergy from food challenge tests and case histories, and were affected by a total of 60 positive allergens (egg 37, milk 11, soy beans 4, wheat 5, rice 3). The concordance, sensitivity, and specificity of HRT with the clinical diagnosis were 85.3%, 66.7% and 92.1%, those of RAST were 59.4%, 90.0% and 48.2%, and those of ST were 84.7%, 71.8% and 88.7%, respectively. The positive predictive values of HRT, RAST and ST were 75.5%, 38.8% and 66.7%. The false positive ratio of HRT (24.5%) was the lowest among all the tests. There was a significant correlation between HRT and RAST (r = 0.513, p < 0.001). However, the concordance of HRT with respect to RAST was 56.0%. The concordance and specificity of HRT in relation to the clinical diagnosis were higher than RAST and the same as ST. The sensitivity of RAST was higher than that of HRT. From these results, we concluded that RAST is good for the screening of allergens and that HRT is a useful diagnostic method for the confirmation of a clinical allergy.

The yeast MOT2 gene encodes a putative zinc finger protein that serves as a global negative regulator affecting expression of several categories of genes, including mating-pheromone-responsive genes

The STE4 gene encodes the beta subunit of a heterotrimeric G protein that is an essential component of the pheromone signal transduction pathway. To identify downstream component(s) of Ste4, we sought pseudo-revertants that restored mating competence to ste4 mutants. The suppressor mot2 was isolated as a recessive mutation that restored conjugational competence to a temperature-sensitive ste4 mutant and simultaneously conferred a temperature-sensitive growth phenotype. The MOT2 gene encodes a putative zinc finger protein, the deletion of which resulted in temperature-sensitive growth, increased expression of FUS1 in the absence of pheromones, and suppression of a deletion of the alpha-factor receptor. On the other hand, sterility resulting from deletion of STE4 was not suppressed by the mot2 deletion. These phenotypes are similar to those associated with temperature-sensitive mutations in CDC36 and CDC39, which are proposed to encode general negative regulators of transcription rather than factors involved in the pheromone response pathway. Deletion of MOT2 also caused increased transcription of unrelated genes such as GAL7 and PHO84. Overexpression of MOT2 suppresses the growth defect of temperature-sensitive mutations in CDC36 and CDC39. These observations suggest that Mot2 functions as a general negative regulator of transcription in the same processes as Cdc36 and Cdc39.

Simultaneous multielemental analysis of daily food samples by inductively coupled plasma mass spectrometry

Several toxic elements in total composite food samples of hospital diets were determined simultaneously by inductively coupled plasma mass spectrometry (ICP-MS). Trace element concentrations of Be, Cr, As, Cd, Sn, Sb, Ce, Hg and Pb changed widely ranging from a few ng.g-1 to less than 3 micrograms.g-1 in all 24 samples collected through a year. Be, Sn, and Hg were not detected in rice sample alone, and other trace elements, with the exception of Cr and As, were less than approximately 50% levels, as compared with mixed diet samples. The daily intakes of these toxic elements were in the ranges of a few to several hundreds of micrograms.