Analysis of the regional anatomy of the retro-oesophageal right subclavian artery and surrounding structures.

BACKGROUND: The retro-oesophageal right subclavian artery (RRSA) is a congenital anomalous branching of the arch of the aorta. Because its incidence is very low, it has not been fully understood how the RRSA develops during embryogenesis, and thus accumulation of observed findings in newly found cases is important to elucidate the aetiology of the RRSA. MATERIALS AND METHODS: We encountered a case of the RRSA during the course of gross anatomy dissection for medical students. RESULTS: The main findings in the present observations are that (a) the RRSA arose from the right side wall of the arch of the aorta as its last branch; (b) the detected RRSA was directed to the right and upward between the oesophagus and vertebral column; (c) the right vertebral artery branched from the RRSA and entered the sixth cervical foramen transversarium; (d) the suprema intercostal artery branched from the costocervical trunk on both sides and its distal branches were distributed to the first and second intercostal spaces; and (e) both sides of bronchial arteries originated from the thoracic aorta. CONCLUSIONS: The present study gives further information about the morphological details of the RRSA leading to better understanding of its developmental process.

Erythroblastic sarcoma in the thoracic cavity of a cow.

Erythroblastic sarcoma in a 10-year-old Japanese Black cow with anemia is described. Tumor masses or nodules were located mainly in the thoracic cavity, and some lymph nodes were slightly enlarged. Although neoplastic involvement of the bone marrow was detected, the cow was not leukemic. The diagnosis was made based on the localized distribution of neoplastic lesions, no increase of intravascular nucleated cell number, deeply eosinophilic cytoplasm in some tumor cells, and frequent immunoreactivity of the tumor cells for hemoglobin. The tumor cells were characterized by marked pleomorphism and atypia; such morphological deviation from their normal counterparts may be connected with functional deviation resulting in the sarcomatous growth of these erythroid cells.

Detection of avian encephalomyelitis virus in chickens in Japan using RT-PCR.

A reverse transcription-polymerase chain reaction (RT-PCR) method was developed for broadly detecting the avian encephalomyelitis virus (AEV). The new primers were based on conserved sequences of the 5'-untranslated region of AEV, because the virus was not detected using previous reported RT-PCR. By applying this method to the chicken samples with suspected AEV infection in Japan, we successfully obtained PCR products of the predicted size from all samples, and we confirmed the presence of AEV via sequence analysis.

Heavy metal contamination status of Japanese cranes (Grus japonensis) in east Hokkaido, Japan--extensive mercury pollution.

Japanese cranes (Grus japonensis) of eastern Hokkaido, Japan, and migrants between the Amur River basin and the eastern China-Korea Peninsula, live around fresh and brackish wetlands. Only a few thousand cranes are confirmed to exist in the world, so they are under threat of extinction. To understand the adverse effects of metal accumulation, we measured concentrations of three heavy metals in the liver, kidney, and muscle of 93 Japanese cranes from Hokkaido. The cranes were classified into six categories according to their sex and three life stages. Cadmium and mercury (Hg: total mercury) showed age-dependent but not sex-dependent accumulation in the liver and kidney. Twenty cranes showed 30 microg/g or higher levels of Hg in dry tissue and five adult cranes had more than 100 microg/g in their livers or kidneys. Cadmium concentrations were generally lower in all samples. Two adult cranes showed extremely high lead levels of more than 30 microg/g in their livers, suggesting lead poisoning. These results have highlighted the widespread and high levels of Hg pollution in Japanese cranes in Hokkaido, Japan.

Augmentation of Helicobacter pylori urease activity by its specific IgG antibody: implications for bacterial colonization enhancement.

Gastric colonization of Helicobacter pylori (H. pylori) occurs in a very early age via infected mothers having H. pylori-specific IgG antibodies that would be transplacentally transferred to infants. In addition, H. pylori urease-specific IgG was associated with chronic gastric atrophy and post-immunization gastritis is usually correlated with a strong local IgG response. These findings indicate that H. pylori-specific IgG antibodies, in particular its urease-specific IgG, may induce unfavorable influence on host resistance against H. pylori. Here, we show that we have found a unique H. pylori urease-specific IgG monoclonal antibody (MAb), termed S3, recognizing the conformational structure of the small subunit Ure-A, which enhanced the urease enzymatic activity. Such enhancement of the H. pylori urease activity induced by 1 microg of S3 was almost completely cancelled by simultaneously added the same amount of L2 MAb, which has a strong and specific inhibitory activity against H. pylori urease and recognizes a liner epitope of 8-mer peptide (F8: SIKEDVQF) within its large subunit Ure-B (Infect. Immun. 69: 6597, 2001). Intravenous pre-administration of purified S3 into BALB/c mice showed significant augmentation for gastric colonization with the susceptible strain Sydney Strain-1 (SS-1). To our knowledge, this is the first demonstration that a H. pylori urease-specific IgG MAb induced an augmentation of their gastric colonization in vivo.

Molecular characterization of Cryptosporidium parvum detected in Japanese black and Holstein calves in Iwate Prefecture and Tanegashima Island, Kagoshima Prefecture, Japan.

Cryptosporidium oocysts were found in 43 out of 77 calves from two farms in Iwate Prefecture and nine farms on Tanegashima Island, Kagoshima Prefecture, Japan. The DNA fragments of 18S ribosomal RNA (18S rRNA) gene were amplified by a nested PCR from 43 oocyst-positive as well as one oocyst-negative samples. All of them were precisely identified as C. parvum by analyzing the nucleotide sequences of the 18S rRNA gene. C. parvum oocyst-positive calves ranged in age from 6 to 13 days old and significantly have watery diarrhea (P<0.05). Sequences of the gene encoding the 60-kDa glycoprotein (GP60) in 43 Cryptosporidium oocyst-positive samples were identical to that of the zoonotic IIaA15G2R1 subtype. We therefore suggest that calves could be potential sources of C. parvum infections in humans.

Disruption of maternal immune balance maintained by innate DC subsets results in spontaneous pregnancy loss in mice.

Dendritic cells (DCs) play an important role in providing an appropriate fetal/maternal balance between Th1 and Th2 during pregnancy. The Th1/Th2 balance seems to be regulated mainly by two distinct DC subsets, DEC-205(+) DCs having the capacity to establish Th1 polarization and 33D1(+) DCs to induce Th2 dominance. Pregnancy is established and maintained by maternal hormones, such as progesterone and estrogen, and the balance of DC subtypes was affected mainly by progesterone, which induced a dose-dependent reduction of the DEC-205/33D1 ratio together with/without a stable amount of estrogen. The DEC-205/33D1 ratio decreased gradually with the progress of pregnancy and rapid augmentation of the ratio was seen around delivery in vivo. Here, we demonstrate that depletion of 33D1(+) DCs during the perinatal period caused substantial fetal loss probably mediated through Th1 up-regulation via transient IL-12 secretion, and pre-administration of progesterone could rescue the fetal loss. Similar miscarriages were also observed when pregnant mice were intraperitoneally (i.p.) injected twice with IL-12 on Gd 9.5 and 10.5. Moreover, prior inoculation of progesterone suppressed the enhanced serum IL-12 production in mice treated with 33D1 antibody, indicating that progesterone might inhibit temporal IL-12 secretion around Gd 10.5 and miscarriage was avoided. These findings suggest the importance of balancing DC subsets during pregnancy and reveal that we can avoid miscarriage by manipulating the activity of the DC subpopulation of pregnant individuals with maternal hormones.

A schematic diagram showing the various components of the embryonic aortic arch complex in the retroesophageal right subclavian artery.

A retroesophageal right subclavian artery, arising from the arch of the aorta as the terminal branch and passing dorsal to the esophagus, was found in five (1.2%) of 428 bodies donated for student dissection at Kumamoto University between 1993 and 2008. The presence of a retroesophageal right subclavian artery has been generally explained to be caused by the persistence of the normally eliminated part of the right dorsal aorta caudal to the seventh intersegmental artery and the disappearance of the normally patent right fourth aortic arch and the part of the right dorsal aorta cranial to the seventh intersegmental artery during the developmental process. However, the parts which remain or disappear are different in each case. With the aim of determining the portions eliminated or persisting and thereby gaining an understanding of the developmental process of the retroesophageal right subclavian artery in each instance, we made schematic diagrams showing the various components of the embryonic aortic arch complex as the prototype just before the anomaly occurred. Based on these diagrams, we conclude that immediately preceding the disappearance of the distal part of the right dorsal aorta and the dorsal part of the right sixth aortic arch, the third intersegmental artery was situated opposite to the fourth aortic arch and the seventh intersegmental artery was situated cranial to the point of junction of the right and left dorsal aortae.

Naïve CD4+ T cells of Peyer's patches produce more IL-6 than those of spleen in response to antigenic stimulation.

Peyer's patches (PPs) are potential sites where specific mucosal immune responses and oral tolerance are induced. The unique features of these immune responses are thought to occur in micromilieu and are largely affected by antigen-presenting cells (APCs) such as dendritic cells. In this study, we investigated the cytokine profiles induced by the activation of CD4(+) T cells of PPs. PP cells from TCR transgenic mice secreted greater amounts of IL-5 and IL-6 than spleen cells after antigenic stimulation. IL-5 was mainly produced by PP non-T cells, whereas IL-6 was secreted by PP CD4(+) cells. PPs contained two major populations including naïve and memory/activated CD4(+) cells; both populations secreted IL-6 upon activation. We also found that CD4(+)/CD62L(hi) naïve cells from PPs secreted a greater amount of IL-6 after stimulation than those from the spleen. Furthermore, subtraction and qPCR analyses revealed that PP CD4(+)/CD62L(hi) cells express a greater amount of transcripts of GA-binding protein ß subunit 1 than those of the spleen. These results suggest that naïve T cells as well as non-T cells and activated/memory T cells from PPs are distinct from their splenic counterparts and thus cause unique immune responses the in intestine.

Importance of gastrointestinal ingestion and macromolecular antigens in the vein for oral tolerance induction.

Oral administration of a certain dose of antigen can generally induce immunological tolerance against the same antigen. In this study, we showed the temporal appearance of ovalbumin (OVA) antigens in both portal and peripheral blood of mice after the oral administration of OVA. Furthermore, we detected 45,000 MW OVA in mouse serum 30 min after the oral administration of OVA. Based on this observation, we examined whether the injection of intact OVA into the portal or peripheral vein induces immunological tolerance against OVA. We found that the intravenous injection of intact OVA did not induce immunological tolerance but rather enhanced OVA-specific antibody production in some subclasses, suggesting that OVA antigens via the gastrointestinal tract but not intact OVA may contribute to establish immunological tolerance against OVA. Therefore, we examined the effects of digesting intact OVA in the gastrointestinal tract on the induction of oral tolerance. When mice were orally administered or injected into various gastrointestinal organs, such as the stomach, duodenum, ileum, or colon and boosted with intact OVA, OVA-specific antibody production and delayed-type hypersensitivity (DTH) response were significantly enhanced in mice injected into the ileum or colon, compared with orally administered mice. These results suggest that although macromolecular OVA antigens are detected after oral administration of OVA in tolerant-mouse serum, injection of intact OVA cannot contribute to tolerance induction. Therefore, some modification of macromolecular OVA in the gastrointestinal tract and ingestion may be essential for oral tolerance induction.

Implications for induction of autoimmunity via activation of B-1 cells by Helicobacter pylori urease.

Besides various gastroduodenal diseases, Helicobacter pylori infection may be involved in autoimmune disorders like rheumatoid arthritis (RA) or idiopathic thrombocytopenic purpura. Such autoimmune disorders are often associated with autoreactive antibodies produced by B-1 cells, a subpopulation of B lymphocytes. These B-1 cells are mainly located in the pleural cavity or mucosal compartment. The existence of H. pylori urease-specific immunoglobulin A (IgA)-producing B cells in the mucosal compartment and of their specific IgM in the sera of acutely infected volunteers suggests the possibility that urease stimulates mucosal innate immune responses. Here, we show for the first time that purified H. pylori urease predominantly stimulates the B-1-cell population rather than B-2 cells, which produce antigen-specific conventional antibodies among splenic B220(+) B cells. The fact that such stimulation of B-1 cells was not affected by the addition of polymyxin B indicates that the effect of purified H. pylori urease was not due to the contamination with bacterial lipopolysaccharide. Furthermore, the production of various B-1-cell-related autoreactive antibodies such as IgM-type rheumatoid factor, anti-single-stranded DNA antibody, and anti-phosphatidyl choline antibody was observed when the splenic B cells were stimulated with purified H. pylori urease in vitro. These findings suggest that H. pylori components, urease in particular, may be among the environmental triggers that initiate various autoimmune diseases via producing autoreactive antibodies through the activation of B-1 cells. The findings shown here offer important new insights into the pathogenesis of autoimmune disorders related to H. pylori infection.

Age-dependent decrease of polymeric Ig receptor expression and IgA elevation in ddY mice: a possible cause of IgA nephropathy.

Individual animals in the closed colony population of ddY mice were analyzed to clarify the major cause of age-dependent elevation of serum IgA and the appearance of human IgA nephropathy (IgAN)-like symptoms. Based on the serum IgA levels, the mice were classified into two subgroups. One was a high serum IgA group with some manifestations of IgAN through aging (ddY(High)), and the other was a normal serum IgA group without IgAN (ddY(Norm)). The ratio of urinary IgA to serum IgA was significantly reduced in ddY(High) mice, suggesting an impaired IgA clearance via secretion through the epithelial barrier. The actual clearance rate of the intravenously injected dimeric IgA in ddY(High) mice was found to be slower than that in ddY(Norm) mice. Furthermore, we found that the polymeric Ig receptors (pIgRs) that mediate transcytosis of IgA were poorly expressed in the glomeruli as well as in the intestine of ddY(High) mice, whereas the pIgRs were more abundantly expressed in ddY(Norm) mice. In addition, the comparative study using polymerase chain reaction showed that decreased pIgR expression occurred at the transcriptional level in the ddY(High) population. Taken together, these results suggest that a systemic defect in pIgR expression may result in impaired IgA secretion and accumulation of IgA in the serum of ddY(High) mice. The age-dependent changes of pIgR expression in the dimeric IgA secretion sites of ddY(High) mice suggest a possible cause for the elevation of serum IgA level and the pathogenesis of IgAN-like disease.

Antigen feeding increases frequency and antigen-specific proliferation ability of intraepithelial CD4+ T cells in alphabeta T cell receptor transgenic mice.

To study how intestinal intraepithelial lymphocytes (IEL) are affected by orally ingested antigen, the phenotypes and responses of the IEL in mice expressing a transgenic T cell receptor alphabeta (TCR alphabeta) specific for ovalbumin (OVA) were analyzed after feeding OVA. In the OVA-fed mice, the abundance of alphabeta-IEL as a proportion of the total IEL population increased and the frequency of CD4+ cells increased within the TCR alphabeta+ IEL population. CD4(+) IEL from OVA-fed transgenic mice proliferated in vitro more markedly in response to antigen stimulation than IEL from mice fed the control diet. These results indicate that antigen-specific proliferation of CD4+ IEL was amplified as a result of oral administration of antigen.

Naive CD4+ T cells exhibit distinct expression patterns of cytokines and cell surface molecules on their primary responses to varying doses of antigen.

The amount of an Ag used for stimulation affects the type and magnitude of T cell responses. In this study we have investigated the primary response of naive CD4(+) T cells derived from OVA-specific TCR-transgenic mice (OVA23-3) upon stimulation with varying doses of the antigenic peptide, OVA(323-339). IL-4 expression was maximal with 50 nM Ag and decreased significantly with increasing doses. In contrast, IFN-gamma expression, which was also detected at 50 nM Ag, increased with increasing doses. The expression patterns of mRNA for the Th2-specific transcription factors GATA-3 and c-Maf were parallel to that of IL-4. These expression profiles were not altered by the addition of anti-IL-4 plus anti-IL-12 mAbs, suggesting that cytokine receptor signaling is not essential. Naive CD4(+) T cells stimulated with 5 nM Ag elicited IgM secretion from cocultured B cells, whereas those stimulated with 50 nM Ag or more elicited apoptosis of B cells. This may be because at lower doses of Ag (5 nM), naive CD4(+) T cells express CD40 ligand and OX40, whereas at higher doses (50 nM), they express Fas ligand. Clearly, the expression of each type of molecule depends on the Ag dose, and different molecules had different expression patterns. Thus, in the primary response, naive CD4(+) T cells can exhibit different functions depending on the dose of Ag.

Resistance to viral infection by intraepithelial lymphocytes in HIV-1 P18-I10-specific T-cell receptor transgenic mice.

For the analysis of mucosal immunity to HIV-1, we have recently established a line of transgenic (Tg) mice expressing the TCRalpha and TCRbeta genes of the murine CTL clone RT1 specific for P18-I10 (RGPGRAFVTI), an immunodominant gp160 envelope-derived epitope of IIIB isolate, restricted by the H-2D(d) MHC-I molecule. Here we examine those cells bearing specific TCR among the intraepithelial lymphocytes (IELs), with flow cytometric analysis using H-2D(d)/P18-I10 tetramers. We observed three distinct CD3(+), tetramer positive populations among the IELs: extra-thymic CD8alphabeta(+), alphabetaTCR T-cells; CD8 alphaalpha+, gammadeltaTCR T-cells; and thymus-derived CD8alphabeta+, alphabetaTCR T-cells. Challenge of these Tg mice with P18-I10 encoded by a vaccinia virus vector, either intrarectally (i.r.) or intraperitoneally (i.p.), revealed that the intraepithelial compartment seems to be a major site for prevention of the spread of viral infection. Such immunity appears due to the thymus-derived, CD8alphabeta+ antigen-specific CTLs together with CD8alphaalpha+ gammadelta cells, which regulate virus spread. This model system for studying CTL based immunity at mucosal sites should prove helpful in developing rational approaches for HIV control.