Characterization of protective immune responses induced by nasal influenza vaccine containing mutant cholera toxin as a safe adjuvant (CT112K)

Immune responses induced by a nasal influenza vaccine with a mutant cholera toxin (CT112K), known to be a safe adjuvant, were characterized in BALB/c mice to confirm the most suitable regimen of this vaccine for humans. Mice received a primary intranasal administration of the adjuvant (0.1 micro g)-combined PR8 vaccine (0.1 micro g) and a secondary administration of the PR8 vaccine alone (0.1 micro g) 4 weeks later. Two weeks after the secondary immunization, the mice were infected with a nonlethal or a lethal dose of PR8 viruses. Nasal and lung wash virus titers 1 or 3 days after infection indicated that complete protection could be provided by secondary immune responses, which had an immediate effect of preventing infection 2 weeks after the secondary immunization. In this two-dose regimen, high levels of secondary IgA, IgG and IgM antibody-forming cell (AFC) responses were induced in the nasal-associated lymphoid tissue and the spleen. In parallel with the AFC responses, high levels of nasal wash anti-PR8 HA IgA, and lung and serum IgG antibody (Ab) responses were induced 2 weeks after the secondary immunization. The two-dose regimen also induced accelerated delayed-type hypersensitivity responses, which exhibited almost the same peak height as that in the case of the primary response. In addition, the two-dose regimen induced a low memory cell activity of cytotoxic T lymphocytes, detected by in vitro culture of spleen cells. Thus, the immediate effect of preventing infection was mainly provided by the secondary Ab responses. Moreover, the levels of nasal wash IgA Abs correlated well with cross-protection against infection with variant viruses in the upper respiratory tract (RT). These results suggest that the major protective factors among Ab and T cell-mediated immune responses, which are induced by the two-dose regimen using CT112K-combined vaccines, are the cross-reactive IgA Abs in the upper RT and the less cross-reactive IgG Abs in the lower RT, and that the two-dose regimen is a suitable vaccination condition for humans.     

Effects of protocatechuic acid, S-methylmethanethiosulfonate or 5-hydroxy-4-(2-phenyl-(E)ethenyl)-2(5H)-furanone(KYN-54) on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced pulmonary carcinogenesis in mice

Modifying effects of dietary exposure of protocatechuic acid (PCA), a natural monophenolic compound, S-methylmethanethiosulfonate (MMTS), an organosulfur compound newly isolated from cauliflower, and 5-hydroxy-4-(2-phenyl-(E)ethenyl)-2(5H)-furanone (KYN-54), a novel retinoidal butenolide compound, on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (10 micromol, [corrected] single i.p. injection)-induced pulmonary carcinogenesis were examined in female A/J mice. Each of the test chemicals was given in diets during initiation or post-initiation phases (PCA, 1000 ppm; MMTS, 100 ppm; KYN-54, 200 ppm). All of these which had been proved to be chemopreventive mainly in digestive-organs carcinogenesis did not exert any preventive effect in this model when the incidence or multiplicity of pulmonary tumors (adenomas) of mice given NNK and the test chemical at the termination of the experiment (4 months) was compared to that of mice exposed to the carcinogen alone. In contrast, the multiplicity of lung tumors of mice receiving KYN-54 during the post-initiation phase was significantly larger than of the animals with NNK alone (P < 0.05), showing that KYN-54 has a promoting effect on pulmonary carcinogenesis in mice. These data indicate an organotropic activity of these compounds and suggest that candidate compounds for cancer chemoprevention need to be carefully examined for effectiveness in multiple organs by different models.     

Beta-catenin (Ctnnb1) gene mutations in diethylnitrosamine (DEN)-induced liver tumors in male F344 rats.

Alterations in multiple phosphorylation sites on exon 3 of the beta-catenin gene have recently been implicated in hepatocarcinogenesis in humans as well as mice. To identify genetic alterations which could be involved in the chemical-induced hepatocarcinogenesis of rats, we analyzed the status of the sites in the beta-catenin gene (Ctnnb1) of liver neoplasms induced by diethylnitrosamine (DEN) in male F344 rats, using the polymerase chain reaction-single strand conformation polymorphism method. In the present investigation, we examined 35 hepatocellular neoplasms (28 adenomas and 7 carcinomas) for the expression of mutations in the region of the beta-catenin gene. Point mutation at codon 32, 35, 37 or 41, which has been reported in human and mouse liver cell carcinomas and/or other cancers, was recognized in eleven (31%) out of 35 lesions (8 adenomas and 3 carcinomas). Our results indicate that Ctnnb1 mutations may contribute to hepatocarcinogenesis in rats. Our finding that Ctnnb1 mutation was present in adenomas as well as carcinomas also suggests that the mutation is a relatively early event in DEN-induced hepatocarcinogenesis in rats.     

Surgical treatment for pulmonary metastases of squamous cell carcinoma of the head and neck

Purpose: As locoregional control of head and neck cancer has improved, distant metastases have become increasingly common problems.Patients and Methods: To determine the role of surgical treatment, we reviewed 32 patients with squamous cell carcinoma (SCC) of the head and neck who underwent thoracotomy for pulmonary metastases.Results: The overall 5-year survival rate was 32%. The 5-year survival rate of the patients with SCC of the oral cavity was significantly poorer than that of the patients with other primary site (15.4% v 45.2%; P = .01). In the patients with single nodule, extent of the tumor was a significant prognostic factor (P = .007). Mediastinal lymph node involvement (P = .004) and pleural invasion (P = .04) also correlated with survival.Conclusion: TNM classification of the primary tumor did not have an impact on survival in this study. Further studies of a large series should be performed to determine the indications and modalities of the surgical treatment for pulmonary metastases of the SCC of head and neck.     

Iron-induced apoptosis in mouse renal proximal tubules after an injection of a renal carcinogen, iron-nitrilotriacetate

Redox-active iron was demonstrated in mouse kidney by Timm's sulphide- silver staining after an injection of a renal carcinogen, iron- nitrilotriacetate (Fe-NTA). The iron was on the apical site of tubular epithelia of the renal proximal convoluted portion and in the tubules of the straight portion 30 min after the Fe-NTA injection. As the epithelial cells of the proximal tubules died, the iron disappeared in the dead cells and was stored in the cytoplasm of the more distal tubular epithelia. Biochemically, redox-active iron in the kidney rapidly increased to four times higher than the control 30 min after the Fe-NTA injection, then decreased to a plateau which was still higher than the control. Iron tightly stored in iron-storage proteins increased gradually by 3 h after the injection and then decreased at 5 h. The iron-induced free radical injuries, such as lipid peroxidation and protein oxidation, were demonstrated in the renal proximal tubules by histochemistry. The nuclei of the proximal tubular epithelia shrank and fragmented with the free radical injuries, and were positive for terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling. DNA ladder was demonstrated in the mice renal cortexes by agarose gel electrophoresis. It was elucidated that redox-active iron caused free radical injuries in the proximal tubules of mice kidneys after the injection of a renal carcinogenic iron (Fe-NTA) and induced the apoptosis of the proximal tubular epithelial cells.      

Chemoprevention of Azoxymethane-induced Rat Colon Carcinogenesis by a Xanthine Oxidase Inhibitor, 1'-Acetoxychavicol Acetate

In our studies to find natural compounds with chemopreventive efficacy in foods, using azoxymethane (AOM)-induced colonic aberrant crypt foci and colonic mucosal cell proliferation as biomarkers, a x an thine oxidase inhibitor, 1′-acetoxychavicol acetate (ACA), present in the edible plant Languas galanga from Thailand was found to be effective. This study was conducted to test the ability of ACA to inhibit AOM-induced colon tumorigenesis when it was fed to rats during the initiation or post-initiation phase. Male F344 rats were given three weekly s.c. injections of AOM (15mg/kg body weight) to induce colonic neoplasms. They were fed diet containing 100 or 500 ppm ACA for 4 weeks, starting one week before the first dosing of AOM (the initiation feeding). The other groups were fed the ACA diet for 34 weeks, starting one week after the last AOM injection (the post-initiation feeding). At the termination of the study (week 38), AOM had induced 71% incidence of colonic adenocarcinoma (12/17 rats). The initiation feeding with ACA caused significant reduction in the incidence of colon carcinoma (54% inhibition by 100 ppm ACA feeding and 77% inhibition by 500 ppm ACA feeding, P=0.03 and P=0.001, respectively). The post-initiation feeding with ACA also suppressed the incidence of colonic carcinoma (45% inhibition by 100 ppm ACA feeding and 93% inhibition by 500 ppm ACA feeding, P=0.06 and P=0.00003, respectively). Such inhibition was dose-dependent and was associated with suppression of proliferation biomarkers, such as ornithine decarboxylase activity in the colonic mucosa, and blood and colonic mucosal polyamine contents. ACA also elevated the activities of phase II enzymes, glutathione S-transferase (GST) and quinone reductase (QR), in the liver and colon. These results indicate that ACA could inhibit the development of AOM-induced colon tumorigenesis through its suppression of cell proliferation in the colonic mucosa and its induction of GST and QR. The results confirm our previous finding that ACA feeding effectively suppressed the development of colonic aberrant crypt foci. These findings suggest possible chemopreventive ability of ACA against colon tumorigenesis.     

A case of duodenal papillary carcinoma complicated by repeated acute pancreatitis

We present a patient with duodenal papillary carcinoma who repeatedly developed acute pancreatitis preoperatively. The patient was a 65-year-old male. In February 1997, the patient consulted a local hospital due to vomiting, high fever, and jaundice. With the diagnosis of obstructive jaundice, percutaneous transhepatic biliary drainage (PTBD) was performed, revealing a distal bile duct obstruction. Because duodenal papillary carcinoma was diagnosed based on endoscopic findings, the patient was admitted to Kurume University Hospital. Hypotonic duodenography (HDG) disclosed a protruding lesion with an irregular surface in the descending part of the duodenum, resulting in a diagnosis of positive duodenal invasion (du1). Because computed tomography (CT) demonstrated a protruding lesion on the medial side of the second portion of the duodenum, positive pancreatic invasion (panc2) was diagnosed. On March 18 and April 22, sudden abdominal pain, leukocytosis, and an increase in serum amylase were noted. CT revealed that the pancreas was diffusely enlarged, showing an ill-defined boundary between the pancreas and adipose tissue and fluid collection. On CT, the lesion was evaluated as Grade 3 and moderate. For treatment, pancreatic enzyme inhibitors and antibiotics were intravenously injected. Peritoneal perfusion was concomitantly performed during the second treatment. Because symptoms remitted thereafter, a pylorus preserving pancreatoduodenectomy (PpPD) was carried out. The postoperative histologic examination revealed negative pancreatic invasion. Concerning the etiology of acute pancreatitis, not pancreatic invasion, but impaction of the liberated tumor mass in the common canal was considered responsible for the repeated pancreatitis because the tumor showed a cauliflower-like shape.     

Mushroom worker's lung resulting from indoor cultivation of Pleurotus osteatus

Indoor cultivation of oyster mushroom Pleurotus osteatus lead to an outbreak of extrinsic allergic alveolitis in two workers. High titer of indirect fluorescent antibody and positive precipitins against basidiospores of P. osteatus were demonstrated in sera of the patients. Mushroom workers should protect themselves from the basidiospores, being aware of their pathogenicity.     

Lack of oral tolerance in aging is due to sequential loss of Peyer's patch cell interactions

Our past studies showed that Peyer's patches were required for the induction of oral tolerance to the protein antigen ovalbumin (OVA), but not to the hapten 2,4,6-trinitrobenzene sulfonic acid (TNBS). In the present study, the effects of immunosenescence on oral tolerance induction were assessed with these two toleragens. Significant reductions in OVA-specific serum IgG antibody and CD4(+) T cell responses to subsequent challenge were observed in OVA-fed, young adult mice. Importantly, these reduced anti-OVA antibody responses were associated with delayed-type hypersensitivity, and antigen-induced CD4(+) T(h)1- and T(h)2-type cytokine responses. On the other hand, aged mice fed OVA failed to develop oral tolerance. Thus, CD4(+) T cells from Peyer's patches produced selected T(h)2- but no T(h)1-type cytokines. The TNP-specific serum IgG antibody and T cell responses were significantly diminished by prior TNBS feeding in young adult, 6- to 8-month-old and 12- to 14-month-old, but not in senescent, 2-year-old mice. Finally, we have directly assessed dendritic cell subsets and T cell responses in Peyer's patches, and their function in tolerance induction was impaired at an earlier stage of life. These results suggest that lack of oral tolerance to the protein OVA during aging is the result of dysfunctional Peyer's patches.