Perforation and postoperative bleeding of endoscopic submucosal dissection in gastric tumors: analysis of 1190 lesions in low- and high-volume centers in Saga, Japan

BACKGROUND

This retrospective study aimed to determine risk factors associated with serious complications of endoscopic submucosal dissection of gastric tumors in multicenters compared between high- and low-volume centers.

METHODS

Between 2001 and 2010, gastric endoscopic submucosal dissection was performed in 1190 lesions of 1082 patients in five hospitals in Saga, three high-volume and two low-volume centers. Risk factors for serious complications were evaluated. Patients' background characteristics were evaluated, including anticoagulants use and underlying diseases.

RESULTS

Postoperative bleeding was detected in 75 patients (6.9%), and perforation was detected in 40 patients (3.7%). Most postoperative bleeding and perforation cases were recovered with endoscopic procedures, although one case of each complication was treated by emergency surgery. Multivariate analysis indicated that risk factors for perforation were tumor location, massive submucusal invasion, endoscopists' experience of 100-149 cases and hypertension, and that risk factors for postoperative bleeding were tumor location, resected tumor size, and scar lesion. The serious complications were not different between high- and low-volume centers.

CONCLUSIONS

The present study indicated that risk factors for perforation during endoscopic submucosal dissection were tumor, endoscopist and patient related, although risk factors for postoperative bleeding were tumor related. There was no difference in complications between high- and low-volume centers.

Effects of unilateral castration on morphologic characteristics of the testis in one-, two-, and three-year-old stallions

The effects of unilateral castration on testicular compensatory hypertrophy were measured in 12 Morgan stallions, four each at one, two, and three years of age. They were randomized within age to intact (IN) or unilaterally castrated (UC) groups. Allotment and surgery were in January 1983 and total castration was in June 1983, 150 d after unilateral castration. Testis weight increased linearly with age (P < 0.01) and was increased by unilateral castration (P < 0.07). Epididymal weight also increased linearly with age (P < 0.05) and was heavier in UC animals (P = 0.15). Tubule diameter (P < 0.10) and epithelial height (P < 0.03) were greater in UC than in IN stallions. In conclusion, testes of stallions underwent compensatory hypertrophy after unilateral castration.

Predicting the efficacy of proton pump inhibitors in patients with non-erosive reflux disease before therapy using dual-channel 24-h esophageal pH monitoring

BACKGROUND AND AIM

We aimed to determine whether reflux- and symptom-related parameters can predict the efficacy of proton pump inhibitors (PPI) in non-erosive reflux disease (NERD).

METHODS

Twenty-seven NERD patients who had experienced heartburn more than once a week within the previous month were enrolled. Intraesophageal pH before therapy was measured simultaneously at 5 and 15 cm above the esophagogastric junction (EGJ) for 24 h. The PPI rabeprazole was administered at a dose of 10 mg once daily for 4 weeks. In the event that heartburn was not relieved, the dose was increased to 10 mg twice daily for an additional 2 weeks, and again to 20 mg twice daily for another 2 weeks.

RESULTS

Univariate analysis demonstrated no significant associations between any reflux- or symptom-related parameters at either site and complete heartburn relief after 4 weeks, or cumulative complete heartburn relief after 8 weeks. However, post-hoc analysis demonstrated more satisfactory heartburn relief after 4 weeks in patients with a high symptom index compared with those with a low symptom index, at 5 cm above the EGJ (P = 0.009). Cumulative satisfactory heartburn relief after 8 weeks was also greater in patients with a high total number of acid reflux episodes compared with those with a low total number of episodes, at 15 cm above the EGJ (P = 0.037).

CONCLUSIONS

Pre-therapeutic pH monitoring in the lower and mid-esophagus is useful for predicting the efficacy of PPI in NERD patients.

Two years' intensive training in endoscopic diagnosis facilitates detection of early gastric cancer

OBJECTIVE

Early detection of gastric cancer by screening endoscopy facilitates endoscopic treatment in place of open surgery. The aim of this study was to evaluate whether 2 years intensive training improved the detection of gastric cancer by screening endoscopy.

METHODS

An endoscopist who had trained for 6 years as a general physician, performed screening endoscopy at Imari Arita Kyoritsu Hospital before (group I) and after (group II) intensive training in the diagnosis of early gastric cancer in consecutive patients.

RESULTS

Background characteristics, including age (61.6 vs. 62.2 years) and sex, did not differ between the groups. Before training, 10 gastric neoplasms were detected in 937 patients in group I: four early gastric cancers, one gastric adenoma, and five advanced gastric cancer. After training, 36 gastric neoplasms were detected in 937 patients in group II: 18 early gastric cancers, 11 gastric adenoma, five advanced gastric cancer, and one each of gastric carcinoid and malignant lymphoma. The detection rate for early gastric cancer was significantly improved by training [group I: 4/937 (0.4%) vs. group II: 18/937 (1.9%)], although the detection rate for advanced gastric cancer did not differ before and after training. The proportion of early gastric cancer + adenoma to advanced cancer was higher in group II (5/5 vs. 29/5 in group I).

CONCLUSION

Intensive training in upper gastrointestinal endoscopy screening dramatically improved the detection rate for early gastric cancer, although the detection rate for advanced gastric cancer was not affected.

Evaluation of hemostasis with soft coagulation using endoscopic hemostatic forceps in comparison with metallic hemoclips for bleeding gastric ulcers: a prospective, randomized trial

BACKGROUND

Endoscopic high-frequency soft coagulation, recently developed in Japan, is available for the management of gastric bleeding in cases of bleeding gastric ulcers and bleeding during endoscopic submucosal dissection. The aim of this study was to evaluate the efficacy of hemostasis with soft coagulation for bleeding gastric ulcers by comparing it with hemoclips in a prospective, randomized trial.

METHODS

During the period of April 2006 to March 2008, 96 patients that had gastric ulcers with bleeding or nonbleeding visible vessels were enrolled in this study. All of the 96 patients were randomly divided into two groups: endoscopic hemostasis with soft coagulation (Group I) or endoscopic hemoclipping (Group II).

RESULTS

A total of 41 (85%) out of 48 patients in Group I and 38 (79%) out of 48 patients in Group II were successfully treated with soft coagulation or clipping alone, respectively. The endoscopic hemostasis rate for the initial modality in combination with another endoscopic procedure performed after the initial method was 98% in both groups. One patient in Group I (2%) and five patients in Group II (10%) experienced recurrent bleeding. The time required to achieve hemostasis was shorter in Group I compared with Group II (9.2 +/- 11.1 vs. 13.6 +/- 9.4 min; P < 0.05).

CONCLUSIONS

This study revealed that soft coagulation is as effective as hemoclipping for treating bleeding gastric ulcers. The time required to achieve hemostasis was shorter with the soft coagulation procedure.

[Two cases of esophageal achalasia, in which localized botulinum toxin injections were effective to improve symptoms]

The cases were a 64-year-old man and a 57-year-old woman both with discomfort and dysphasia. They were given a diagnosis of esophageal achalasia after gastrointestinal endoscopy, barium esophagography and esophageal internal pressure tests. Their symptoms were dramatically improved by localized botulinum toxin injections, which were commonly available in the US. The localized botulinum toxin injection treatment is safe and minimally invasive with few complications. It is effective to reduce symptoms in esophageal achalasia.

Endoscopic hemostasis with metallic hemoclips for iatrogenic Mallory-Weiss tear caused by endoscopic examination

AIM

Applied endoscopic techniques including mucosal resection, sclerotherapy and endoscopic retrograde cholangiopancreatography (ERCP) have been advanced and iatrogenic complications including Mallory-Weiss tear (MWT) occasionally occur in daily endoscopic procedures. The present study aimed to examine the advantages of clipping for MWT complications that occur during endoscopic examination.

METHODS

Over 10 years, we experienced 47 patients with bleeding caused by MWT. Metallic hemoclips were applied for 38 patients for hemostasis. These patients were categorized into two groups: 18 patients in group A whose bleeding tear occurred during endoscopic examination in an iatrogenic condition, and 20 patients in group B visited the emergency unit due to other etiology of MWT.

RESULTS

The background characteristics, including length of tears, were not different between the two groups. Initial hemostasis was 100% in groups A and B. Rebleeding was 0/18 (0%) in group A and 1/20 (5 %) in group B. Number of patients who received blood transfusion was significantly higher in group B (group A: 0/18, group B: 4/20). Hemoglobin level before hemostasis was 12.5 g/dL in group A which was not different to that in group B, 10.9 g/dL.

CONCLUSION

Application of hemoclips was effective for bleeding MWT during endoscopic procedures, which warranted prophylactic application of hemoclips on MWT during endoscopic examination.

A case of advanced colonic cancer that developed from residual laterally spreading tumor treated by piecemeal endoscopic mucosal resection

This case report showed a laterally spreading tumor treated by endoscopic mucosal resection that developed as an advanced colon cancer. A 74-year-old female was visited to treat a colon tumor that was pointed out at another hospital. Total colonoscopy revealed a laterally spreading tumor (LST) 25 mm in diameter in the cecum. The lesion was diagnosed as homogenous granular type LST (G-type LST) and treated by endoscopic piecemeal mucosal resection in January 2004. A tumor was recognized by follow-up endoscopic examination in April 2006. The scar of endoscopic piecemeal mucosal resection had developed to advanced colon cancer and was treated by laparoscopy-associated ileocecal resection with D3 lymph node resection. Previous reports indicated that G-type LST in the colon could be treated by piecemeal resection, but this report suggests that G-type LST resected by piecemeal endoscopic mucosal resection might develop to advanced colon cancer.

Dysphagia in adult Japanese is not equivalent to the grade of endoscopic reflux esophagitis

OBJECTIVE

This study was aimed to evaluate the correlation between dysphagia, detected by nursing staff in a brief interview and endoscopic findings in reflux esophagitis.

PATIENTS AND METHODS

A total of 8,031 Japanese subjects without medication for gastrointestinal disease were briefly asked about the presence of heartburn, dysphagia, odynophagia, and acid regurgitation by nursing staff before endoscopy for assessment of esophagitis utilizing the Los Angeles Classification.

RESULTS

The grade of endoscopic esophagitis was not equivalent to symptoms of dysphagia in 8,031 subjects. We evaluated the characteristics of subjects who complained of only dysphagia. Univariate analysis indicated that non-smoking, and non-drinking females were associated with a higher risk for dysphagia, and multivariate analysis indicated the gender was associated with dysphagia. There was no association of dysphagia with herniation and distribution of age.

CONCLUSION

This study indicated that dysphagia was not equivalent to the endoscopic findings according to a brief interview by nursing staff and that dysphagia might be more common in females and those who do not smoke or drink.

A pilot randomized control study to evaluate endoscopic resection using a ligation device for rectal carcinoid tumors

AIM: Rectal carcinoid tumors smaller than 10 mm can be resected with local excision using endoscopy. In order to remove rectal carcinoid tumors completely, we evaluated endoscopic mucosal resection with a ligation device in this pilot control randomized study.

METHODS: Fifteen patients were diagnosed with rectal carcinoid tumor (less than 10 mm) in our hospital from 1993 to 2002. There were 9 males and 6 females, with a mean age 61.5 years (range, 34-77 years). The patients had no complaints of carcinoid syndrome symptoms. Fifteen patients were randomly divided into 2 groups: 7 carcinoid tumors were treated by conventional endoscopic resection, and 8 carcinoid tumors were treated by endoscopic resection using a ligation device.

RESULTS: All rectal carcinoid tumors were located at the middle to distal rectum. The size of the tumors varied from 3 mm to 10 mm and background characteristics of the patients were not different in the two groups. The rate of complete removal of carcinoid tumors using a ligation device (100%, 8/8) was significantly higher than that of conventional endoscopic resection (57.1%, 4/7). The three patients had tumor involvement of deep margin, for which additional treatment was performed. No complications occurred during or after endoscopic resection using a ligation device. All patients in the both groups were alive during the 3-year observation period.

CONCLUSION: Endoscopic resection using a ligation device is a useful and safe method for resection of small rectal carcinoid tumors.

Disseminated Ochroconis gallopavum infection in a chronic lymphocytic leukemia: a case report and review of the literature on hematological malignancies

Disseminated fungal infection is an important cause of morbidity and mortality among patients with hematological malignancies. Ochroconis gallopavum is a dematiaceous and thermotolerant fungus that causes opportunistic infections in immunocompromised hosts. About only 30 cases of this organism infection have been reported worldwide. We report a disseminated Ochroconis gallopavum infection in a B-cell chronic lymphocytic leukemia patient. In spite of intensive anti-fungal treatment, no improvement in the clinical condition was observed and the patient died 4 months after diagnosis of the infection. Ochroconis gallopavum infection is a potentially fatal disease in hematological malignancies.

Changes of oligosaccharides and fatty acids in monkey hippocampus by synaptic potentiation

We measured the release of free fatty acids and structural changes of glycoprotein glycans induced by tetraethylammonium (TEA) salt in hippocampal slices of cynomolgus monkey brain. The release of free fatty acids in the hippocampal slices occurred after synaptic potentiation by TEA in a different manner from rat hippocampus. Arachidonic acid release in monkey hippocampus occurred much faster than that in rat. Several types of glycans of monkey hippocampal glycoproteins were determined depending on the duration time after TEA treatment. 5-Mannose was increased within 2 min, while polysialoglycans were increased after 5 min or later. Comparative study of glycans of monkey and rat hippocampal slices revealed the presence of relatively larger amount of sialo- and multi-anntenary glycans in rat than in monkey. These results indicate that the depolarizing stimulation of monkey hippocampal slices induced the change of glycoprotein glycan structures and release of free fatty acids in a different manner from rat hippocampus.

Microbiological contamination in genetically modified animals and proposals for a microbiological test standard for national universities in Japan

The Biosafety Committee of the Japanese Association of Laboratory Animal Facilities of National Universities (JALAN) investigated recent episodes of microbiological contamination in genetically modified mice (GMM), and the countermeasures taken when the contaminated GMM were introduced into animal facilities, by questionnaires addressed to 53 animal facilities belonging to JALAN and serological tests. Although almost all of the contaminated GMM were accepted with conditions such as rederivation after or before reception and housing in designated rooms, contamination with a spectrum of microorganisms was demonstrated in GMM transferred domestically and from abroad. In serological tests, Mycoplasma pulmonis, mouse parvovirus, and mouse encephalomylitis virus were detected in GMM transferred from domestic facilities and from abroad. The present results of the questionnaires and serological tests suggest that GMM are highly and widely contaminated with microorganisms compared with mice from commercial breeders. Thus, we propose a microbiological requirement, including microbiological status--excellent, common, and minimum--as a guide for the transfer and procurement of mice and rats in Japan.

Prevalence of herpes B virus antibody in nonhuman primates reared at the National University of Japan

A serological investigation by means of an enzyme immuno assay test for herpes B virus (cercopithecine herpesvirus 1) was performed on 961 sera of healthy nonhuman primates reared in laboratory animal facilities which belong to the Association of Laboratory Animal Facilities of the National University of Japan. An antibody prevalence of 40% (384/ 961) was demonstrated. The antibody titer was shown to be higher among macaques (60% of cynomolgus monkeys, 53% of rhesus monkeys, and 34% of Japanese monkeys) than among non-macaque species (21%). These data indicate that nonhuman primates reared in animal facilities may present an occupational health problem and a potential zoonotic biohazard as demonstrated in limited cases in the United States.

Alpha-galactosidase transgenic mouse: heterogeneous gene expression and posttranslational glycosylation in tissues

We produced six transgenic mouse lines expressing human alpha-galactosidase (alpha-Gal) in order to evaluate its posttranslational modification. Among them, serum alpha-Gal activity increased 3000-fold in two transgenic mouse lines (TgN2 and TgN51), as compared to that in non-transgenic lines. The heart and liver of the TgN2 mouse expressed a high amount of transcript as well as high alpha-Gal activity. Its gene products in the heart and kidney were sensitive to endoglycosidase H digestion, but those in the spleen and liver were largely resistant. Glycopeptidase F treatment confirmed an identical molecular mass for the peptide moiety of the enzyme. We concluded that heterogeneous molecular mass of the gene products was caused by different degrees of posttranslational glycosylation in murine tissues.

Four conductance levels of cloned cardiac L-type Ca2+ channel alpha1 and alpha1/beta subunits

Formation of single channel subconductance is one of the unique characteristics of the L-type Ca2+ channel. Although alpha1 subunit exhibits a primary function of the channel, it remains uncertain whether alpha1 subunit alone is able to produce subconductance. We tested this by studying single channel currents of cloned cardiac alpha1 subunit expressed in Chinese hamster fibroblast cells, with/without coexpression of cardiac beta subunit. The alpha1 subunit exhibited four distinct levels of conductance (22.7, 14.3, 6.2 and 3.2 pS). Coexpression of beta subunit significantly increased the number of openings in all four levels of conductance without changing the conductance values.

Acetylcholine reactivates latent pseudorabies virus in mice

The latency model of pseudorabies virus (PrV) wild strain, YS-81, in mice was established and latent PrV reactivated with acetylcholine. The latent PrV was reactivated from the trigeminal ganglia with acetylcholine. It was found that this model is useful in investigating the mechanism of latent PrV reactivation by acetylcholine.

Perceptions of sexual harassment: the effects of gender, legal standard, and ambivalent sexism

This research tests the possibility that the reasonable woman as compared to the reasonable person test of hostile work environment sexual harassment interacts with hostile and benevolent sexist beliefs and under some conditions triggers protectionist attitudes toward women who complain of sexual harassment. We administered to a sample of undergraduates the ambivalent sexism inventory along with the fact patterns in two harassment cases and asked them to make legally relevant decisions under either the reasonable woman or person standard. We found that those high in hostile sexism, and women, found more evidence of harassment. However, those high in benevolent sexism did not exhibit the hostile sexism effects. Although men were less sensitive to the reasonable woman standard than women, under some conditions the reasonable woman standard enabled both genders to find greater evidence of harassment. The results are discussed from the perspectives of law and psychology.

Rabies virus M protein expressed in Escherichia coli and its regulatory role in virion-associated transcriptase activity

Rabies virus M protein was expressed in Escherichia coli in the form of a fusion protein with maltose binding protein (MBP) and purified by amylose affinity column chromatography after extraction. In order to investigate the possible regulatory role of M protein in viral transcription, an assay system for rabies virion-associated transcriptase activity was established by using the ribonucleoprotein (RNP) cores prepared from purified virions. Analysis of the products of the transcription assay system showed that the products are sensitive to RNase and are positive-strand RNA. Addition of the fusion protein to the system after cleavage with a proteinase Factor Xa (FXa), which cleaves the fusion protein into the M protein and MBP, resulted in an efficient and dose-dependent inhibition of the transcription. Furthermore, addition to the system of anti-M protein monoclonal antibody significantly restored the transcription. Control experiments with the same transcription assaying system using rabies virus nucleoprotein expressed as a fusion protein with MBP and cleaved with FXa did not result in an inhibition of the transcription. These results suggest that the M protein of rabies virus has the property to down-regulate virion-associated transcription.

Acetylcholine activates latent pseudorabies virus in pigs

Pseudorabies virus (PrV) was isolated from the nasal swabs and the cultured trigeminal ganglia of latently infected pigs after they were treated with acetylcholine (ACH). These results indicate that ACH activates latent infections of PrV.

Target cells of cytotoxic T lymphocytes directed to the individual structural proteins of rabies virus

Target cells of cytotoxic T lymphocytes (CTL) directed to the individual structural proteins (except for the large polymerase (L) protein) of rabies virus were established by expressing only the respective protein in murine neuroblastoma (NA) and murine macrophage (J774-1) cell lines. Mice infected with the ERA strain of rabies virus developed CTL responses to all of these rabies virus proteins. The cytotoxic activity was abrogated by pretreatment of the effector cells with anti-CD8 monoclonal antibody (MAb) and complement but not with anti-CD4 MAb. Cell lysis by CTL was blocked in the presence of anti-major histocompatibility complex (MHC) class 1 antibodies in J774-1 cell lines. Rabies virus-infected cells express these proteins at the surface, which can be recognized and lysed by the respective CTL. Mice immunized with beta-propiolactone-inactivated virus induced a CTL response against glycoprotein but not against internal viral components. This assay system might be useful for further analysis of the possible contribution of these proteins in the cell-mediated immune protection against rabies.

Protective efficacy in mice of post-exposure vaccination with vaccinia virus recombinant expressing either rabies virus glycoprotein or nucleoprotein

Mice vaccinated intraperitoneally (i.p.) with 10(7) p.f.u. of a vaccinia virus recombinant expressing either the glycoprotein (rVac-G) or nucleoprotein (rVac-N) of rabies virus 3 weeks before challenge were protected against peripheral lethal infection. Similarly, by post-exposure vaccination in which mice were first infected with rabies virus and subsequently vaccinated i.p. with the recombinant, rVac-G conferred protection when given immediately following infection and up to 24 h after infection. Prior treatment of those mice with anti-CD8 monoclonal antibodies (MAb) did not significantly affect the outcome of the infection. In contrast, rVac-N failed to confer protection even with higher doses (10(8) p.f.u.) of the virus or even when administered by the intradermal route. Anti-nucleoprotein antibody production by these mice was not suppressed by prior rabies virus infection and the levels and the time of antibody production were similar to those of anti-glycoprotein antibody production in mice vaccinated with rVac-G after rabies virus infection. The cytotoxic T lymphocyte response was also not down-regulated by rabies virus in the mice that were given rVac-N. Possible mechanism(s) for the ineffectiveness of rVac-N by post-exposure vaccination in contrast to pre-exposure vaccination was discussed.

A unique mutation of glycoprotein gene of the attenuated RC-HL strain of rabies virus, a seed virus used for production of animal vaccine in Japan

Although the RC-HL strain of rabies virus is avirulent in adult mice, the amino acid at position 333 of its G protein is arginine, which is thought to be necessary for virulence in adult mice upon intracerebral inoculation of the virus. This result suggests that besides arginine at position 333, some other positions of G protein might also be involved in determining the virulence of rabies virus.

Linear and conformation-dependent antigenic sites on the nucleoprotein of rabies virus

A set of 29 monoclonal antibodies (MAbs) specific for the rabies virus nucleoprotein (N protein) was prepared and used to analyze the topography of antigenic sites. At least four partially overlapping antigenic sites were delineated on the N protein of rabies virus by competitive binding assays. Indirect immunofluorescent antibody tests using MAbs with a series of rabies and rabies-related viruses showed that epitopes shared by various fixed and street strains of rabies virus were mainly localized at antigenic sites II and III, while epitopes representing the genus-specific antigen of Lyssavirus were widely presented at sites I, III and IV. All but one of seven MAbs specific for antigenic sites I, IV and bridge site (I and II) reacted with the antigen that had been denatured by sodium dodecyl sulfate or 2-mercaptoethanol, as well as with the denatured N protein in Western blotting assays. However, none of the MAbs against antigenic sites II and III reacted with the denatured antigen. These data indicate that antigenic sites I and IV, and sites II and III on the N protein of rabies virus are composed of linear and conformation-dependent epitopes, respectively.

Nucleotide sequence of the nucleoprotein gene of the RC.HL strain of rabies virus, a seed strain used for animal vaccine production in Japan

By using a phage vector (lambda ZAP II) and the mRNA extracted from IMR-32 cells infected with the RC.HL strain of rabies virus, we constructed a cDNA library from which four nucleoprotein (N)-specific cDNA clones were obtained by Southern blot hybridization. These clones contained a cDNA insert of about 1.4 kb, in which the longest open reading frame was the same length as that reported for the N cDNA of three fixed strains, CVS, PV, and SAD B19. When the nucleotide and deduced amino acid sequences were compared between the RC.HL and the three strains, homology was within the range of 91.5-91.8% and 95.1-96.0%, respectively. Of 183 nucleotides of the RC.HL N-cDNA that were not identical to that of the corresponding site of at least one of the three strains, 41 were shared with the CVS strain, whereas only three were shared with either of the other two strains. In the amino acid sequence, we found 29 residues that were not shared in common with all of the four strains, 11 of which were the substitutions with radically different amino acids that might cause conformational changes of the protein, and, in addition, five of which were located in the region close to the C terminus. The number of such amino acid substitutions between the RC,HL and CVS strains was smaller than that of the other three strains. These results are not inconsistent with the presumption that the RC.HL and CVS strains originated from the same laboratory strain of the Pasteur viruses.

Resistance of mice vaccinated with rabies virus internal structural proteins to lethal infection

Mice were vaccinated with recombinant vaccinia virus (rVac) expressing the glycoprotein (G), nucleoprotein (N), phosphoprotein (NS) or matrix protein (M) of rabies virus and their resistance to peripheral lethal infection with street rabies virus was examined. Mice vaccinated with rVac-G or rVac-N developed strong antibody responses to the corresponding proteins and essentially all mice survived challenge infection. Mice vaccinated with rVac-NS or rVac-M developed only a slight antibody response, however, a significant protection (59%) was observed in the rVac-NS-vaccinated mice, whereas rVac-M-vaccinated mice were not protected. No anti-G antibodies were detected in the sera of mice which has been vaccinated with rVac-N or rVac-NS and survived challenge infection. Passive transfer of anti-N monoclonal antibodies (MAbs) recognizing an epitope located on amino acids 1-224 of the protein prior to challenge resulted in significant protection, although the protection was not complete even with a high amount of antibodies. In contrast, none of the mice given MAbs recognizing an epitope of amino acids 247-415 or F(ab')2 fragments from a protective MAb IgG were protected. Administration of anti-CD 8 MAb to rVac-N-vaccinated mice showed no significant effect on protection. Our observations suggest that a considerable part of the protection achieved by the vaccination with rVac-N can be ascribed to the intact anti-N antibodies recognizing an epitope located on amino acids 1-224 of the protein.

Comparative sequence analysis of the M gene among rabies virus strains and its expression by recombinant vaccinia virus

Nucleotide sequences and the deduced amino acid sequences of the gene encoding the matrix (M) protein of the Nishigahara and the CVS strains of rabies virus have been determined. The M gene is 609 nucleotides long and is capable of coding for a peptide composed of 202 amino acids. Sequence comparison of these M genes with those of other stains [Pasteur (PV), ERA, Avol] revealed that there is 89.7-91.5% homology at the nucleotide level, and 90.1-92.1% homology at amino acid level, between almost all combinations of these strains. However, in the combinations of the PV and ERA strains, and the virulent CVS and the avirulent CVS-derived Avol strains, much higher homology was observed both at the nucleotide and amino acid levels. The predicted secondary structure and hydropathy profiles also exhibited similar features. Recombinant vaccinia virus containing the M gene was constructed. Sodium dodecyl sulfate (NaDodSO4)-polyacrylamide gel electrophoresis of the precipitates obtained by immune reaction of the recombinant virus-infected cell lysate with a monoclonal antibody against the M protein revealed that electrophoretic mobility of the expressed protein is indistinguishable from that of the authentic M protein from rabies virions.

Suppression of cell-mediated immunity by street rabies virus infection

An attempt to define a severe suppression of cell-mediated immunity by street rabies virus infection was undertaken by using the mice lethally and peripherally infected with a street rabies virus (1088 strain). The cell-mediated cytotoxic (CMC) activity of the spleen cells from those mice once slightly increased until day 4 after infection but declined rapidly thereafter until their death on days 10 to 12 after infection. In parallel with a decrease of CMC response of the spleen cells from 1088-infected mice, proliferative response to Con A, IL-2 activity in the culture supernatants of Con A-induced proliferation, responsiveness to exogenously added IL-2 and to Con A to express IL-2R, of those cells became suppressed, and the marked decrease of the total number of spleen cells was observed. Selective depletion of CD4+ and CD8+ cells in the spleens, abnormalities of IL-1 and E-type prostaglandins (PGE2) production or production of inhibitory component able to block IL-2 activity by spleen cells were not observed and these factors did not appear to be associated with the suppression of proliferative response to Con A. However, an apparent association of CD8+ cells in the suppression of differentiation of pre-cytotoxic lymphocytes (CTL) into CTL was demonstrated in the co-culture experiments of the spleen cells from 1088-infected mice with spleen cells of mice infected with an attenuated rabies virus (ERA strain) which can induce higher levels of CMC response. There was no evidence of the productive replication of rabies virus in thymus and spleen of 1088-infected mice. The relationship of these observations to current theories on virus-induced immunosuppression was discussed.

Mapping of the antigenic determinants recognized by monoclonal antibodies against the M2 protein of rabies virus

Twenty-one hybridomas producing monoclonal antibodies (moAbs) against the M2 protein of the Nishigahara (RECH) strain of rabies virus were prepared using the SDS-polyacrylamide gel-purified M2 protein as the immunogen. All moAbs reacted with the protein after Western blotting of rabies virus. By combinations of competitive binding assays, examination of the reactivity of moAbs to the cells infected with parent RCEH and two other strains, CVS and HEP-Flury, and immunoprecipitation with in vitro translation products derived from full-length and truncated cDNAs of the M2 gene, these moAbs could be classified into seven epitope groups. Of these, 20 moAbs belonging to six epitope groups were suggested to recognize an antigenic determinant in the amino-terminal region, from the 1st to the 72nd amino acid of the protein (8 moAbs from two groups directed to amino acids 1 to 72; 2 moAbs from a group directed to amino acids 9 to 72; 5 moAbs from a group directed to amino acids 17-72; 5 moAbs from two groups directed to amino acids 32 to 72). The antigenic determinant recognized by the remaining 1 moAb was shown to be located in the amino acid region from 50 to 171. These moAbs should be useful for further studies on the biological functions of the M2 protein of rabies virus.

Conserved nucleotide sequence of rabies virus cDNA encoding the nucleoprotein

The cDNAs of rabies virus (the CVS strain) encoding the structural proteins (G, N, NS, and M) were cloned. Of these clones, the nucleotide sequence of the cDNA encoding the nucleoprotein was determined to compare with those of other strains of rabies virus. The comparison confirmed that the nucleotide sequences and deduced amino acid sequences are highly conserved among strains including an avirulent strain.

Effects of monensin on subcellular structure, thyroglobulin secretion and peroxidase activity of cultured thyroid cells obtained from patients with hyperthyroidism

The effects of monensin on subcellular structure, release of thyroglobulin (TG) and peroxidase (PO) activity were investigated using primary cultures of thyroid cells obtained from patients with Basedow's disease (Basedow's cells). TG concentration in the culture medium was measured by a sandwich enzyme immunoassay and the amount of TG in cultured cells was measured with an identical sandwich enzyme immunoassay after lysis of the cells with Triton X-100. PO activity of cultured cells was measured by a biochemical method. Addition of TSH (10 mU/ml/day) to the culture medium increased the synthesis and release of TG. When monensin (1 micron/l) was added to the medium on the last day of a 3-day incubation with TSH, the Golgi complex showed vacuolative change ultrastructurally, and the amount of intracellular TG was increased, whereas the amount of TG in the culture medium and PO activity became lower than those in the control group. These results suggest that in cultured Basedow's cells, TG is secreted through the Golgi complex, and that the activity of PO is elevated after processing in the Golgi complex.

Protection against rabies in mice by a cytotoxic T cell clone recognizing the glycoprotein of rabies virus

By the use of liposomes containing the purified surface glycoprotein (G) of rabies virus and the haemagglutinin-neuraminidase (HN) and fusion (F) glycoproteins of Sendai virus, the target antigen of anti-rabies virus cytotoxic T lymphocyte (CTL) clones isolated in a previous study was identified as the G protein. Recognition of the H-2K determinant of the class I major histocompatibility complex (MHC) was necessary for target lysis by the CTL clones. One of the CTL clones was examined for the ability to protect mice against a lethal rabies virus infection. CTL were transferred into syngeneic mice which had been infected in the hind footpad with the ERA strain of rabies virus. The infection was converted into a lethal infection by cyclophosphamide treatment 1 day after virus infection. Transfer of CTL 2 to 3 days after virus infection protected approximately 50% of mice during the observation period of 4 weeks. Greater protection was obtained in mice receiving both anti-rabies virus antibodies and CTL cells.

Induction of peroxidase and thyroglobulin by TSH in cultured thyroid cells from patients with Basedow's disease and its inhibition by actinomycin D

The effects of TSH on peroxidase activity (PO) and thyroglobulin (TG) production were investigated using primary cultures of thyroid cells obtained from patients with Basedow's disease (Basedow's cells). PO activity of cultured cells and TG concentration in the culture medium were measured by biochemical and sandwich enzyme immunoassays, respectively. The addition of TSH (10 mU/ml/day) to the medium did not increase the cell number but did increase the PO activity and TG concentration. It took more than 3 days for the PO activity of cells cultured with TSH (stimulated group) to reach a level twice that of cells cultured without TSH (control group), whereas 2 days of incubation with TSH was sufficient for increasing the TG concentration. When actinomycin D (AD) was added to the medium on the first day of 3-day incubation with TSH, the stimulatory effect of TSH on PO was completely blocked and the TG concentration was reduced to half that of the control group. AD given to the stimulated group on the last day of induction produced no inhibitory effect on the induction of PO activity by TSH, but reduced the TG concentration to almost half that in the stimulated group. An electron microscopic study of Basedow's cells cultured with AD and TSH failed to reveal any cytopathic change. The findings of the present study suggested that in cultured Basedow's cells TSH induces PO activity and TG production through the synthesis of new messenger RNA.

Microneutralization test for rabies virus based on an enzyme immunoassay

We have developed an enzyme immunoassay for rabies virus by using acetone-fixed infected cell cultures as the antigen. This test was used to demonstrate virus-neutralizing antibodies in human and animal sera and was as sensitive as and easier to perform than the rapid fluorescent-focus inhibition technique.

Enhanced antibody responses in mice by combined administration of interferon with rabies vaccine

Exogenous interferon administered to mice at the time of, and 6 hours after the first dose of 3 daily vaccinations accelerated and enhanced the IgM and IgG antibody responses to rabies virus. The effect of interferon was not evident when the interferon was administered later in the vaccination schedules and was abrogated by prior administration of anti-interferon antibody to the mice. The number of IgM antibody secreting cells in the spleen was significantly greater in mice treated with interferon than in controls.

Further studies on an improved haemagglutination inhibition test with higher sensitivity for rabies virus antibody

The efficiency of the removal of non-specific inhibitors of rabies virus haemagglutinin by treatment with colloidal silicic acid, which was proposed in an earlier study, was examined in a number of test samples. The non-specific inhibitors were removed in 289 out of 296 normal human sera (97.6%) by this treatment to a level that was undetectable at the 1:4 starting dilution in the haemagglutination inhibition test. Antigenic differences among three strains of rabies virus were detected in the haemagglutination inhibition test and the antibody titres to the homologous antigens were apparently higher than those to heterologous antigens.

Effect of monensin on the synthesis, maturation and secretion of vesicular stomatitis virus proteins in a monensin-resistant Chinese hamster ovary cell line

We compared the effects of the cationic ionophore, monensin, on the synthesis, maturation and release of vesicular stomatitis virus (VSV) in cultures of Chinese hamster ovary (CHO) cells and the monensin-resistant clone, MonR-31. Our results depended on the dose and time of the addition of monensin to the infected cells, from 1 h prior to VSV infection to 1 h after infection. VSV production was more resistant in MonR-31 than in CHO cells when the ionophore was added 1 h prior to VSV infection. Monensin added 1 h after VSV infection showed the opposite phenomenon; release of virus particles into the medium was 10- to 10(5)-fold less in MonR-31 cells than in CHO cells, and the intracellular virus number in the resistant cells was one-third to one-fourth of that in the parental CHO cells. Syntheses of all virus-associated G, N and M proteins were inhibited in both cell lines by monensin, but especially so in the MonR-31 cells. There were no marked qualitative changes in the biochemical properties of viral glycoprotein G in virus-infected CHO and MonR-31 cells treated with monensin after virus infection. An endoglycosidase H-resistant G with a molecular weight smaller than that of normal G and attachments of palmitate or fucose on the truncated G protein appeared. Alteration of the secretion of as well as the synthesis of the enveloped virus is discussed in relation to the monensin susceptibility of the resistant MonR-31 clone.

Methods of increasing the sensitivity of the haemagglutination inhibition test for rabies virus antibody

A new method for the removal of non-specific inhibitors of rabies virus haemagglutinin has been developed. Treatment with colloidal silicic acid (Aerosil) or with acetone plus Aerosil reduced the non-specific inhibitors in human, mouse, and dog sera to a level that was undetectable at the 1:4 starting dilution in the haemagglutination inhibition test.Bromelain-treated goose erythrocytes were much more susceptible to haemagglutination by rabies virus than were untreated erythrocytes, and the sensitivity of the haemagglutination inhibition test was considerably increased by using bromelain-treated erythrocytes. Low levels of antibodies in sera from immunized human subjects were detected with higher sensitivity by combining Aerosil treatment of the sera with the use of bromelain-treated goose erythrocytes in the haemagglutination inhibition test.

pH-dependent hemolysis and cell fusion of rhabdoviruses

Human erythrocytes pretreated with fungal semialkali protease or trypsin became susceptible to hemagglutination by vesicular stomatitis virus (VSV) and rabies virus. Both viruses exhibited extensive hemolytic and fusion activities against erythrocytes pretreated with these enzymes. The hemolysis and fusion were pH dependent and the activities were most apparent at pH 5.0 and decreased with increase in pH. However, VSV still exhibited slight hemolytic activity at neutral pH. Hemolysis was also dependent on the dose of virus and was inhibited by treatment of the viruses with antiviral antibody. Results of sodium dodecyl sulfate polyacrylamide gel electrophoresis of erythrocyte membranes suggested that most of the carbohydrates were removed from the membrane proteins by the treatment with proteolytic enzymes.

[Antigenic variants of rabies virus in France. Monoclonal antibodies]

One hundred and sixteen rabies field isolates from France were studied with monoclonal antibodies for analysis of their nucleocapside antigenic characteristics (by direct or indirect immunofluorescence) or glycoprotein determinants (by neutralization in mice). These studies verified that nucleocapside antigens had only two variants, apparently uncorrelated to animal species or geographic areas. Glycoprotein antigens had also variants which could explain partial defection in cross protection observed in mice having received rabies vaccine prepared from heterologous strains.