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Biomedical subjects

K Hirayama

Publications and source records attributed to K Hirayama.

At least 19 recordsLinked to original sources

Pleomorphic adenoma of the salivary gland in two dogs.

Pleomorphic adenomas of the salivary gland were diagnosed in two dogs. The tumours were single, firm and well circumscribed, with a smooth cut surface. Metastatic tumours were not detected. Histopathological examination revealed that the tumours contained multiple cysts lined with luminal epithelial cells and myoepithelial cells, and mucinous, myxochondroid and cartilaginous tissues. Immunohistochemical examination demonstrated labelling of luminal epithelial cells and myoepithelial cells, and mucinous, myxochondroid and cartilaginous tissues with antibodies to cytokeratin LU-5, AE1/AE3, CK-14, CALP, a-SMA, vimentin, GFAP, and S-100. Labelling for GFAP indicated stromal transformation into myxoid and chondroid tissues.

Adenoma, Pleomorphic↗

Monocarboxylate transporter 1 gene expression in the ovine gastrointestinal tract.

In this study, we investigated the tissue distribution and expression of monocarboxylate transporter 1 (MCT1) along the gastrointestinal tract of sheep. Western blot analysis suggested the presence of MCT1 as a 43-kDa protein in immunoblots of membranes from the various tissues examined. The results of Western blotting were further confirmed by immunohistochemical studies, which revealed intense immunoreactivity for the MCT1 protein in the forestomach (rumen, reticulum and omasum) and large intestine (caecum, proximal and distal colon). Moderate reactivity, however, was detected in the abomasum, while no immunoreactivity could be seen in any regions of the small intestine examined. Furthermore, MCT1 was expressed at the mRNA level as determined by reverse transcriptase polymerase chain reaction (RT-PCR), which showed a band of the expected size (300 bp) in all tissues examined. From these results we concluded that MCT1 protein is highly expressed and distributed in the stomach and large intestine of sheep suggesting that MCT1 may play a significant role in the transport of short chain fatty acids and their metabolites in the gastrointestinal tract of ruminants.

Animals↗

Medullary sponge kidney in a 10-year-old Shih Tzu dog.

Medullary sponge kidney was diagnosed in a 10-year-old male Shih Tzu dog with a long history of hyposthenuria, but with no other findings indicating renal failure or hormonal aberration. At the dog's death from heart failure, an autopsy was performed. On gross morphology, bilateral kidneys were normal size and had many cysts ranging from the corticomedullary junction to renal papillae. Histopathologic findings showed that almost all of the cysts were lined by monolayered or multilayered and columnar or cuboidal epithelium with chilium similar to epididymis. Immunohistochemically, all of these cells were strongly positive for AE1/AE3 and negative for vimentin. Many of these cells were positive for cytokeratin 7 (CK7), and only a few cells were positive for desmin. The results of staining are the same as those for epithelium of the collecting duct of normal canine kidney. This is the first report of this pathologic entity in the canine kidney.

Animals↗

Subcortical calcification on CT in dural arteriovenous fistula with cortical venous reflux.

We report 3 cases of dural arteriovenous fistula (dAVF) with cortical venous reflux (CVR) presenting calcification in the cortico-medullary junction at the bottom of cerebral sulci on unenhanced CT. This likely results from chronic venous congestion with resulting impaired perfusion of the involved parenchyma. dAVF with CVR, which is known to have poor prognosis without treatment, should be included in the differential diagnosis of subcortical calcification on CT.

Aged↗

Expression and distribution of monocarboxylate transporter 1 (MCT1) in the gastrointestinal tract of calves.

In the present study the expression and distribution of monocarboxylate transporter 1 (MCT1) along the gastrointestinal tract (rumen, reticulum, omasum, abomasum, duodenum, jejunum, ileum, cecum and colon) of calves were investigated on both mRNA and protein levels. The expression of MCT1 protein and its distribution were determined by Western blotting and immunohistochemical staining, respectively by using antibody for MCT1. MCT1 protein was visualized as a 43-kDa band on immunoblots of the membrane proteins prepared from the various regions examined, and it was more highly expressed in forestomach and large intestine than in abomasum and small intestine. With the use of reverse transcriptase-polymerase chain reaction, mRNA encoding for MCT1 was demonstrated in the different tissues examined. The immunohistochemical study confirmed the Western blot findings and showed strong MCT1 immunopositive staining in the stratified squamous epithelia of the forestomach as well as the epithelial cells lining the digestive tract in the cecum, proximal colon, and distal colon. The results suggest that MCT1 may play a role in the transport of SCFA and their metabolites in the gastrointestinal tract of bovines.

Amino Acid Sequence↗

Associations between frequencies of a susceptible TNF-alpha promoter allele and protective alpha-thalassaemias and malaria parasite incidence in Vanuatu.

Tumour necrosis factor-alpha (TNF-alpha) is one of the key cytokines that influence the pathology of microbial infections. The genetic susceptibility to severe forms of falciparum malaria is differentially associated with TNF-alpha promoter gene polymorphisms (TNFP alleles). In a previous study, we identified a TNFP-allele characterized by a C to T transition at position -857 (TNFP-D allele) as a marker for susceptibility to cerebral malaria in Myanmar. The frequencies of TNFP alleles on six islands of Vanuatu, Melanesia (South-west Pacific) were estimated to investigate whether malaria selection pressure on this susceptibility marker has influenced its prevalence. Within the archipelago of Vanuatu there is a decreasing cline of parasite incidence from North to South. Of the four alleles of the TNFP gene detected in Vanuatu, the TNFP-D allele frequencies were inversely correlated with the parasite incidence of islands; TNFP-D varied from 0.55 on the island with the lowest parasite incidence to 0.26 on the island with the highest parasite incidence (r = -0.855, P = 0.03). We also observed a significant correlation between the frequencies of alpha-thalassaemia alleles, thought to protect against malaria and parasite incidence in the same populations. These data are consistent with a previously reported correspondence between the frequencies of glucose 6-phosphate dehydrogenase (G6PD) deficiency and parasite incidences on the islands of Vanuatu (Kaneko et al. 1998) and indicate that the degree of malaria endemicity has influenced the allele frequencies of at least three loci that confer both susceptibility (TNFP-D) and protection (alpha-thalassaemias and G6PD deficiency).

Alleles↗

Nutcracker syndrome associated with severe anemia and mild proteinuria.

A 70-year-old man was referred to our hospital with the chief complaint of gross hematuria. Urinalysis revealed gross hematuria (3+, RBC 100/HPF or more) and mild proteinuria (3+, 1.8 g/day) with no urinary casts. Computed tomography of the abdomen showed compression of the left renal vein between the superior mesenteric artery and the aorta. Ultrasonography showed an increased flow velocity at the stenotic portion of the left renal vein. An aortography and selective left renal arteriography showed that there was no evidence of tumor vessels or arterial abnormalities in the arterial phase. However, the venous phase revealed a stenosis of the left renal vein just lateral to the aorta as well as a reflux of contrast material toward the left gonadal vein which was dilated. In addition, cystoscopy revealed left ureteral bleeding. Based on these findings, we made the diagnosis of gross hematuria caused by nutcracker syndrome (NCS). We concluded that the main cause of the anemia and proteinuria in our patient was leakage of blood and this is confirmed by the relationship of red blood cells to protein in the urine because we proved whole blood and plasma protein loss in the urine by calculation. Fourteen months after discharge, both the gross hematuria and proteinuria spontaneously disappeared. This case strongly suggested that the first therapy for hematuria and proteinuria with NCS should be observation.

Aged↗

Experimental vertical transmission of Borna disease virus in the mouse.

We demonstrated the experimental vertical transmission of Borna disease virus (BDV) in pregnant BALB/c mice. Giessen strain He/80 of BDV was used in the present study. Six six-week-old mice were inoculated intraperitoneally with 10(5) 50% tissue culture infective doses (TCID50), and were bred immediately. Four pregnant mice were sacrificed under anaesthesia on the 10th and 14th days after vaginal plug formation. Nine newborns from two maternal mice were sacrificed under anaesthesia on the 7th day after birth. Positive signals with RT-nested PCR techniques for BDV p24-RNAs were seen in the fetuses, placentas and brains of all newborn mice. No immunopositivities for BDV p40 were found in the fetuses or placentas at 10 days' gestation. BDV p40 immunopositivities were found in neurons of the fetal brains and in decidual cells of the placentas at 14 days' gestation. They were also found in neurons of the brains of newborn mice. At 10 days' gestation, no positive signals for BDV p40 sense or antisense riboprobes were seen in the fetal brains or placentas. Positive signals were found in neurons of the fetal brains and decidual cells of the placentas at 14 days' gestation. Positive signals for BDV p40 sense and antisense riboprobes were found in almost all neurons throughout the brains of nine newborn mice. These results suggest that persistent infection with BDV in newborn mice may be induced by vertical transmission during gestation.

Animals↗

Glomerular crescents predominantly express cadherin-catenin complex in pauci-immune-type crescentic glomerulonephritis.

AIMS: To investigate the expression of the cadherin complex in human crescentic glomerulonephritis to elucidate the role of intercellular adherens junction molecules in crescent formation. METHODS AND RESULTS: Immunostaining revealed cadherin complexes localized in Bowman's epithelial cells, but not in podocytes, of normal human glomeruli. Eight adult cases with myeloperoxidase anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA)-related (pauci-immune type) crescentic glomerulonephritis were examined on immunofluorescence microscopy with anti-pan cadherin, p120 catenin, and beta-catenin antibodies. The specimens provided six cellular crescents, 12 fibrocellular crescents, and four fibrotic crescents. Immunofluorescence was semiquantitatively estimated by the rate of the field of localization within the whole area of the crescent, according to the four-grade system [(-) - (++)]. All the tested molecules consisting of the cadherin complex were abundantly observed in cytokeratin-positive epithelial components in crescents, each with an equivalent area of localization. The expression of the cadherin complex was closely associated with that of cytokeratin and both diminished as the crescents developed from cellular to fibrotic. CONCLUSIONS: The cadherin-catenin complex is a specific marker of Bowman's epithelial cells in human glomeruli. The cellular crescents in pauci-immune-type crescentic glomerulonephritis possess adherens junction molecules, indicating a principle parietal epithelial cell phenotype.

Adherens Junctions↗

Formant interaction as a cue to vowel perception: a case report.

Accumulating evidence indicates that cerebral processing of consonants and vowels is separable. It has been shown that disordered temporal acuity leads to disturbed consonant perception in cases with pure word deafness. In contrast, there has been no clear explanation of how vowel perception is impaired. We examined a patient with auditory agnosia, who showed a differential ability to identify the five Japanese vowels after bilateral cerebral lesions. He correctly identified the vowel [a] in more than 70% of auditory presentations, whereas he identified [i] in only about 30% of presentations. The difference between the first and second formant frequencies "F2-F1" and an artificially defined value "F1-(F2-F1)" for each vowel correlated significantly with the percentage of correct identifications. These findings support the hypothesis that vowel perception is based on formant interactions.

Adult↗

Probiotic mixture decreases DNA adduct formation in colonic epithelium induced by the food mutagen 2-amino-9H-pyrido[2,3-b]indole in a human-flora associated mouse model.

Consumption of probiotic bacteria such as bifidobacteria has been shown to reduce the risk of colon cancer in animal models. However, the composition and metabolic activities of the intestinal flora of experimental animals are significantly different from those of humans. The aim of the study was to examine whether the probiotic mixture, which consisted of Streptococcus faecalis, Clostridium butyricum and Bacillus mesentericus, could decrease DNA adduct formation induced by 2-amino-9H-pyrido[2,3-b]indole (2-amino-alpha-carboline; AAC) in the colonic epithelium of a human-flora-associated (HFA) mouse model. Ten HFA mice were divided into a control group (n=4) and a probiotic group (n=6). The control group was administered AAC for 3 days and sacrificed 24 h after the last dose. The probiotic group was administered the probiotic mixture for 2 weeks prior to the administration of AAC. Analysis of DNA adducts with the 32P-high-performance liquid chromatography method was performed on stomach, jejunum and colonic epithelium, representing direct exposure sites of AAC, and colon wall, liver and kidney, representing indirect exposure sites. The mean level of the DNA adducts in the colonic epithelium of the probiotic group was significantly lower than that of control group, while the mean levels at the other sites did not differ significantly between the groups. The results indicated that the probiotic mixture could decrease the DNA adduct formation in the colonic epithelium induced by AAC.

Animals↗

Limbic encephalitis presenting with topographical disorientation and amnesia.

A case of paraneoplastic limbic encephalitis presenting with topographical disorientation is reported. A 70 year old woman became unable to identify familiar buildings and landscapes and could not recall the way to destinations she had known very well for years. She also showed attentional disturbance and severe anterograde amnesia. Her retrograde amnesia extended for one year at most. No other neuropsychological deficits were noted. Thus her topographical disorientation was of the primary form. Specific tests related to topographical disorientation showed that her two main symptoms seem to fall into the categories of landscape agnosia and heading disorientation. T2 weighted magnetic resonance imaging revealed high intensity signals in the anteromedial temporal lobes bilaterally, in the right posterior parahippocampal gyrus, in the right retrosplenial region, and in the right inferior precuneus. Anti-Hu antibody was found in the serum. This case shows that topographical disorientation can be a primary symptom of limbic encephalitis.

Aged↗

Invasive ductal carcinoma of the mammary gland in a mare.

A 21-year-old thoroughbred mare had a 35 x 14 x 10 cm mass involving the mammary gland. Metastases were found in the kidneys, lungs, skeletal muscles, and regional lymph nodes. Histopathologic examination of the tumor revealed a ductal solid carcinoma with extensive intraductal and intralobular involvement and focal infiltration of the adjacent stroma. The intralobular neoplasms were divided into irregularly shaped islands and sheets of polygonal and spindle-shaped epithelial cells by thick or thin fibrous connective tissue bundles. The neoplastic cells had a small or moderate amount of cytoplasm that stained faintly with eosin and round or oval hyperchromatic nuclei. Immunohistochemically, the neoplastic cells were strongly positive for Lu-5, weakly positive for AE1/AE3, vimentin, and glial fibrillary acidic protein, and negative for cytokeratin 8, cytokeratin 14, alpha-smooth muscle actin, calponin, and S100. The neoplasm was diagnosed as an invasive ductal carcinoma of the mammary gland with multiple metastases.

Animals↗

Immunohistochemical evaluation of a malignant intestinal carcinoid in a dog.

An intestinal carcinoid with multiple metastases was identified in a 5-year-old male Shih Tzu with a clinical history of anemia, fatigue, anorexia, vomiting, intermittent diarrhea, intestinal bleeding, and progressive emaciation. There was a yellowish-white mass 15 mm in diameter in the anterior jejunum and white nodules consistent with metastases in many organs. Histopathologically, the mass consisted of neoplastic cells arranged in lobules, trabeculae, or closely interdigitating islands of cells. Neoplastic cells were generally polygonal with round hyperchromatic nuclei, modest amounts of eosinophilic cytoplasm, and eosinophilic cytoplasmic granules. Mitoses were common. Rosette formations of tumor cells were apparent in metastatic tumors. Immunohistochemically, tumor cells stained positive for cytokeratin 13, synaptophysin, protein gene product 9.5, neuron-specific enolase, chromogranin A, calcitonin gene-related peptide, serotonin (5-HT), and Leu-7. Serum 5-HT concentrations for this dog were increased 10-fold compared with those of normal dogs. All findings were consistent with a diagnosis of a malignant intestinal carcinoid.

Animals↗

Immunohistochemical detection of apolipoprotein A-I and B-100 in canine atherosclerotic lesions.

We attempt to determine and compare the localization of apolipoproteins (apo) apoA-I and B-100 in atherosclerotic lesions of canine aortas, coronary arteries, and the peripheral arteries, using immunohistochemical techniques. Histopathologically, atherosclerotic lesions were characterized by deposition of lipids and infiltration of lipid-laden foamy cells in the tunica intima and tunica media, sometimes forming fibrofatty plaques containing abundant sudanophilic and mineralized material. Canine apoA (CapoA)-I and canine apoB (CapoB)-100 immunopositive signals were simultaneously observed in mild and severe atherosclerotic lesions of the aorta, coronary arteries, splenic arteries, and renal arteries in the double-immunolabeled sections. Both CapoA-I and CapoB-100 positive signals were seen in the cytoplasm of endothelial cells, smooth muscle cells, and macrophages. The subendothelial space and extracellular matrix in the tunica intima and media were also positive. Neither CapoA-I nor CapoB-100 positive signals were seen in normal arteries. These findings closely resemble those of the localization of apoA-I and apoB-100 in human atherosclerotic lesions.

Animals↗

[The optimal procedure for chylothorax after operation for thoracic esophageal cancer; reasonable approaches to the thoracic duct from the point of view of routes for esophageal replacement].

In general, chylothorax after esophagectomy with lymph node dissection under thoracotomy is a rare postoperative complication. We report a 71-year-old man who developed chylothorax following esophagectomy and 3-field lymph node dissection together with reconstruction using stomach through the posterior mediastinum, and discuss ideal approaches that are less invasive and make it possible to provide better exposure of the thoracic duct. In selecting the ideal approach, the most important thing is differences in routes for esophageal replacement. The anatomical relation between the location of a conduit adopted for reconstruction of the resected esophagus and the thoracic duct should be considered in each case. In the case of the retrosternal or antesternal route, a video-assisted thoracoscopic approach allows for easy detection of the thoracic duct while reducing surgical invasiveness, because there is no conduit in the posterior mediastinum. On the other hand, a conduit interrupts the visual field of thoracoscopy in the case of the posterior mediastinal or intrathoracic route. Drawing up of a conduit to gain a good operative field involves some risks in protection of the vascular pedicle. Therefore, a transabdominomediastinal approach is an optimal option. With this approach, we could easily find the thoracic duct and directly ligate it just cranial to the hiatus, resulting in a remarkable decrease in discharge through the thoracic drainage tube. In addition, we present an intelligible intraoperative photograph.

Aged↗