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Biomedical subjects

T Iwaki

Publications and source records attributed to T Iwaki.

At least 91 records · Page 5Linked to original sources

Non-isotopic in situ hybridization of CD44 transcript in formalin-fixed paraffin-embedded sections.

We established a protocol for the non-isotopic in situ detection of adhesion molecule CD44 messenger RNA (mRNA) in archival formalin-fixed paraffin-embedded sections of human surgical materials. Four brain tumor samples with different histopathologies (a metastatic adenocarcinoma, a metastatic squamous carcinoma, a glioblastoma and a craniopharyngioma) were thus studied using a 157 nt digoxigenin-labeled RNA probe complementary to the common mRNA region to all the CD44 isoforms. The CD44 transcript was detected in the cytoplasm of glioma and such epithelial tumor cells as metastatic carcinoma and craniopharyngioma. A competitive hybridization study confirmed the specificity of the CD44 probe. The optimization of critical conditions are also discussed. This protocol should therefore be useful in making an accurate evaluation of mRNA localization and may also facilitate the successful completion of extensive retrospective studies on a large number of archival samples.

Brain Neoplasms↗

Characterization of the Na+-ATPase gene (ZENA1) from the salt-tolerant yeast Zygosaccharomyces rouxii.

In order to clarify the relationship between the salt tolerance of Zygosaccharomyces rouxii and the function of Na+-ATPase, a gene which exhibited homology to the Na+-ATPase gene (ZENA1) of Saccharomyces cerevisiae was isolated from Z. rouxii. This newly isolated gene (ZENA1) encoded a product of 1048 amino acids. The predicted amino-acid sequence of Zena1p was highly homologous to that of S. cerevisiae Ena1p and Ena2p, and Schwanniomyces occidentalis Ena1p and Ena2p, but showed low homology to that of Zpma1p, which is the product of the Z. rouxii plasma membrane H+.ATPase gene (ZENA1). Zena1p shares the peptide motifs which have been suggested to participate in the function of ATPase. Expression of ZENA1 was observed, but was independent of NaCl shock. When ZENA1 was expressed in salt-sensitive S. cerevisiae under the regulation of a GAL1 promoter by using the expression vector pYES2, salt tolerance of the transformants was observed. The growth characteristics of Zena1Delta-disruptants of Z. rouxii and the pH profiles of their plasma membrane ATPase activity were almost the same as those of the wild-type strain, indicating that the function of Zena1p is of little relevance to the salt tolerance property of Z. rouxii. By considering the close relationship between the salt tolerance of Z. rouxii and the function of its Na+/H+-antiporter, we concluded that the extrusion of Na+ across the plasma membrane in Z. rouxii cells might be carried out mainly via the function of the Na+/H+-antiporter in a high salinity environment.

Journal Article↗

Argyrophilic grains in late-onset Creutzfeldt-Jakob diseased brain.

Braak's argyrophilic grains (ArG) are spindle-shaped structures originally described in patients with dementia. Herein, a unique case of sporadic Creutzfeldt-Jakob disease (CJD) accompanied by numerous ArG is presented. The pathological picture was typical of CJD based on the findings of routine hematoxylin-eosin staining. The highest density of ArG was observed throughout the parahippocampal gyrus and the temporal gyri; however, the sector CA1 of the hippocampus showed less ArG. An immunohistochemical analysis for prion protein (PrP) revealed diffuse fine neuropil staining in the cerebral cortex, while the ArG themselves did not demonstrate any immunoreaction for PrP. No correlation was observed between the densities of ArG and either the presence of senile plaques, neurofibrillary tangles or neuropil threads in the present case. To our knowledge, this is the first report of CJD demonstrating numerous ArG.

Aged↗

Brain injury does not modify transmissible spongiform encephalopathy caused by intraperitoneal inoculation with Fukuoka-1 strain.

The pathogenesis of neuroinvasion in Creutzfeldt-Jakob disease and other transmissible spongiform encephalopathies following the peripheral uptake of a disease agent is still not fully understood. The possibility of neuroinvasion either being established or being accelerated by an insult to the brain has not previously been tested. The experiment described herein was designed to examine this possibility by wounding the brain following an intraperitoneal challenge with a mouse-adapted strain of human transmissible spongiform encephalopathy, Fukuoka-1 strain. The results showed that brain injury introduced in any period before the appearance of cerebral abnormal prion protein deposition modified neither the clinical features, including the incubation period, nor the histopathology of the mice. Our findings suggest that neurovirulence of the agent may not be sufficiently promoted by brain injury.

Animals↗

Hakata antigen, a new member of the ficolin/opsonin p35 family, is a novel human lectin secreted into bronchus/alveolus and bile.

Hakata antigen was first reported as a serum protein that reacted with an autoantibody from patients with systemic lupus erythematosus. Recently, it has been found that Hakata antigen is a new member of the ficolin/opsonin p35 family, which is a distinct lectin family, on the basis of homology of structures and the common characteristic of possessing lectin activity. In this study we analyzed the tissue distribution of Hakata antigen. Hakata antigen mRNA and protein were generated in the lung and liver. In the lung, Hakata antigen was produced by both ciliated bronchial epithelial cells and Type II alveolar epithelial cells and was secreted into the bronchus and alveolus. In the liver, Hakata antigen was produced by bile duct epithelial cells and hepatocytes and was also secreted into the bile duct. These results demonstrate that Hakata antigen is a unique lectin protein that exists not only in serum but also in bronchus/alveolus and bile, and indicate that Hakata antigen plays a role in bronchus/alveolus and bile under physiological conditions.

Antibodies, Monoclonal↗

[The prognostic value preoperative promontory testing in Japanese cochlear implant patients].

The prognostic value of preoperative promontory testing was evaluated in Japanese cochlear implant patients. Promontory testing consisted of measurement of electrical thresholds (T), uncomfortable level (UCL), dynamic range (DR), gap detection (GAP), and temporal difference limen (TDL). Patients' performances were measured at 3 months (n = 46) and 1 year (n = 20) postoperatively, using a standard Japanese audiologic test battery without lip-reading. This study included only postlingual deaf patients who received the Nucleus multichannel cochlear implant. Wide DRs at low frequencies (50,100,200 Hz) and good GAP detection (< 20 ms) emerged as excellent preoperative predictors of the 3-month postoperative performances (P < 0.05). In contrast, any measurements could not serve as a good predictor of the 1-year performances. These results suggest that the preoperative promontory testing provides useful information only for early postoperative performances but that it could not predict the final language performances.

Adolescent↗

Macrophage infiltration and heme oxygenase-1 expression correlate with angiogenesis in human gliomas.

Macrophages are key participants in angiogenesis. In this study on human brain tumors, we first investigated whether macrophage infiltration is associated with angiogenesis and malignant histological appearance. Immunostaining of macrophages and small vessels in resected glioma specimens indicated that numbers of infiltrating macrophages and small vessel density were higher in glioblastomas than in astrocytomas or anaplastic astrocytomas. Macrophage infiltration was closely correlated with vascular density in human gliomas. Heme oxygenase-1 (HO-1), which is the rate-limiting enzyme in heme catabolism, was also associated with activated macrophages. Expression of mRNA encoding HO-1 was correlated with macrophage infiltration and vascular density in human glioma samples. Infiltrating macrophages were positively stained with anti-HO-1 antibody by immunohistochemical analysis, and in situ hybridization for HO-1 indicated that HO-1 was expressed in infiltrating macrophages in gliomas. HO-1 gene may be a useful marker for macrophage infiltration as well as neovascularization in human gliomas.

Adolescent↗

[An autopsy case with lower motor neuron disease showing a transient-appearance of anti-GM1 antibody and an improvement of conduction block after gamma-globulin administration].

We report a 63-year-old man who died of respiratory failure. He was well until 1992 (57 years of his age), when he had an onset of progressive weakness of the bilateral upper limbs. He showed no improvement with TRH administration in other hospital. On January 12, 1994, he admitted to our department because of the progressive muscle weakness. Neurologic examination revealed a muscular atrophy associated with severe weakness and hyporeflexia in both upper limbs, and fasciculation were seen in his tongue. Electrophysiological studies revealed mild conduction block in the left medial nerve, and F-waves were not evoked in the left ulnar nerve and bilateral median nerves. After an administration of 25 g/day of human gamma-immunoglobulin for 5 days, conduction block as well as F-wave abnormalities in the left median and left ulnar nerve were improved, yet no improvement of muscle weakness was seen. The anti-GM1 IgG titer was transiently elevated in the patient's serum after gamma-immunoglobulin therapy. On September 8, 1994, subtotal gastrectomy was performed because of the early stage gastric cancer. Histological examination showed poorly differentiated adenocarcinoma (signet-ring cell carcinoma). His muscle weakness had been gradually extended to the lower limbs and he couldn't walk himself on January, 1998. On March, 1998, he developed tetraplegia, mild dysphagia, dysuria and the respiratory disturbance. On April 12, 1998, he admitted to our department for the second time. Neurologic examination revealed a muscular atrophy and fasciculation associated with severe weakness in all of his limbs, tongue and musclus masseter. Neither deep tendon reflex nor pathologic reflex was evoked in his upper and lower extremities. His ocular movements and sensations were well preserved. He died of respiratory failure on May 1, 1998. The patient was presented in a neurological CPC. Neurological and laboratory findings suggested a spinal progressive muscular atrophy (SPMA). However, there were several unusual points as a typical SPMA in this case, that is, an improvement of the electrophysiological abnormalities by gamma-globulin treatment, as well as transient elevation of anti-GM1 antibody. The clinical neurologists have arrived at the conclusion that the patient had lower motor neuron syndrome associated with anti-ganglioside antibody and cause of death was ascribed to the respiratory failure. We discussed whether this case was SPMA or multifocal motor neuropathy. Postmortem examination revealed numerous diverticulums in the ascending colon and lymphothyroiditis. No recurrent carcinoma was detected. Neuropathologically, both severe atrophy of the anterior spinal roots, and severe gliosis and neuronal loss in the anterior horn of the spinal cord were observed. Onuf nuclei were not affected. Neurogenic muscular atrophy was detected in the tongue, diaphragm, and limb muscles. Motor neurons of the brainstem were relatively preserved, but skein-like inclusions as detected by anti-ubiquitin antibody, were present in the facial and hypoglossal nuclei. Neither motor cortex nor cortico-spinal tracts were affected. Demyelination, remyelination or cellular infiltrations were not apparent in the right median nerve and sciatic nerves. The neuropathologic features were compatible with SPMA.

Autoantibodies↗

[Temporal lobe epilepsy associated with old intracerebral hemorrhage due to capillary telangiectasis in the temporal lobe: case report].

A case of 45-year-old female, who presented with temporal lobe epilepsy was reported. The patient was found to have old intracerebral hemorrhage due to capillary telangiectasis in the temporal lobe. On the intraoperative electrocorticography, frequent paroxysmal activities were recorded independently both on the medial and lateral aspects of the temporal lobe. Even after resection of the lateral temporal lobe, frequent paroxysmal discharges were noted on the hippocampus. Histologically, there are astrogliosis and hemosiderin deposits in the white matter around the telangiectasis and the old hematoma. It is postulated that the hippocampus gained secondary epileptogenicity.

Adult↗

[A case of congenital non-progressive cerebellar ataxia with pigmentary retinal degeneration, fiber type disproportion and hypercreatine kinasemia].

We report a 20-year-old female who presented with congenital non-progressive cerebellar ataxia, pigmentary retinal degeneration, fiber type disproportion, hypercreatine kinasemia and mental retardation. No family history of neuromuscular disorders was found. There was consanguinity between the grandfather and grandmother. Pregnancy and delivery were uneventful. Although neck control was obtained at three months old, she could walk at 23 months old. She had a tendency to tumble. Her mentality was retarded. At 12-years-old, she was diagnosed as having pigmentary retinal degeneration. When she visited to our hospital at 20-year-old, she had slight scoliosis. Neurological examination disclosed mental retardation, pigmentary retinal degeneration, gaze evoked nystagmus on horizontal gaze and proximal dominant muscle weakness. Tandem gait was unsteady. Deep tendon reflexes were slightly hyperactive in all four extremities. The serum creatine kinase was elevated to 2346U/l. Muscle biopsy revealed type I. fiber atrophy and predominance. This case is therefore considered to be cogenital non-progressive cerebellar ataxia presenting with fiber type disproportion, pigmentary retinal degeneration and hypercreatine kinasemia.

Adult↗

The choleretic effects of N-acetylglucosaminides, major urinary metabolites of ursodeoxycholic acid, in bile fistula rats.

We investigated the effects of three bile acids conjugated with N-acetylglucosamine, ursodeoxycholate N-acetylglucosaminide, tauroursodeoxycholate N-acetylglucosaminide and glycoursodeoxycholate N-acetylglucosaminide, on bile flow and biliary excretion of various markers in comparison with ursodeoxycholic acid, tauroursodeoxycholic acid and glycoursodeoxycholic acid in bile fistula rats. These bile acids were infused intravenously at a constant rate of 0.3 or 0.6 micromol/min/100 g b.w. for 2 h. All bile acids examined increased bile flow in a dose-dependent manner. In particular, ursodeoxycholate N-acetylglucosaminide has a longer-lasting effect after its infusion on bile flow than the other bile acids. Furthermore, these bile acids markedly increased biliary total bile acid excretion. At a higher dose level, the coefficient of determination (r2) between the biliary total bile acid excretion and bile flow for ursodeoxycholate N-acetylglucosaminide (r2 = 0.39) was lower than that for the other bile acids (r2 = 0.75-0.92). The ursodeoxycholate N-acetylglucosaminide, as well as tauroursodeoxycholic acid, glycoursodeoxycholic acid, tauroursodeoxycholate N-acetylglucosaminide and glycoursodeoxycholate N-acetylglucosaminide, was mostly excreted in an unchanged form in bile, whereas ursodeoxycholic acid was excreted as a conjugate with taurine. The three N-acetylglucosaminides as well as ursodeoxycholic acid, tauroursodeoxycholic acid and glycoursodeoxycholic acid significantly increased the biliary excretion of cholesterol, phospholipid, bilirubin and total Ca2+. In contrast, the N-acetylglucosaminides significantly decreased in biliary bicarbonate concentration, whereas ursodeoxycholic acid significantly increased biliary bicarbonate concentration. However, tauroursodeoxycholic acid and glycoursodeoxycholic acid did not significantly change the biliary bicarbonate concentration. The results indicate that N-acetylglucosaminides have a choleretic effect in bile fistula rats. Our present study also demonstrates that N-acetylglucosaminides, but not ursodeoxycholic acid, tauroursodeoxycholic acid or glycoursodeoxycholic acid, can significantly reduce the biliary bicarbonate concentration. Furthermore, our findings suggest that ursodeoxycholate N-acetylglucosaminide may partly exert a choleretic effect via mechanisms different from those of the other bile acids.

Animals↗

Characterization of a second gene (ZSOD22) of Na+/H+ antiporter from salt-tolerant yeast Zygosaccharomyces rouxii and functional expression of ZSOD2 and ZSOD22 in Saccharomyces cerevisiae.

We reported in our previous paper on the characterization of the Na+/H(+)-antiporter gene (ZSOD2) closely related to the salt-tolerance of yeast Zygosaccharomyces rouxii. In the present paper, we have cloned a second gene (ZSOD22) of Na+/H+ antiporter from Z. rouxii. The deduced amino acid sequence of Zsod22p was highly homologous to that of Zsod2p, Sod2p from Schizosaccharomyces pombe, and Nhalp from Saccharomyces cerevisiae. The open reading frames (ORFs) from ZSOD2 or ZSOD22 were inserted into a yeast expression vector pYES2, and their constructs (pZSOD2 and pZSOD22) were used to transform the salt-sensitive S. cerevisiae. pZSOD2- or pZSOD22-harboring-recombinant S. cerevisiae cells showed increases in salt tolerance. However, the Z. rouxii disruptant of ZSOD22 did not show any phenotypes related to salt tolerance or osmotolerance, unlike that of ZSOD2. The transcriptional expression of ZSOD22 was not observed by Northern blot analysis even in Z. rouxii cells subjected to NaCl-shock. From these results we conclude that although Z. rouxii includes at least two copies of the Na+/H(+)-antiporter gene (ZSOD2 and ZSOD22), ZSOD2 encodes a functional product as an antiporter and ZSOD22 is poorly transcribed, if at all.

Amino Acid Sequence↗

A comparative study of abnormal prion protein isoforms between Gerstmann-Sträussler-Scheinker syndrome and Creutzfeldt-Jakob disease.

Proteinase K (PK)-resistant prion protein (PrPres) isoforms were examined in three patients with Gerstmann-Sträussler-Scheinker syndrome (GSS) carrying proline-to-leucine mutation at codon 102 in prion protein gene (PRNP), and in nine patients with sporadic Creutzfeldt-Jakob disease (CJD). PrPres isoform termed 'type A', which showed a more prominent band of highly glycosylated form than both a lower glycosylated band and an unglycosylated band in immunoblotting, was exclusively found in the GSS patients examined. In eight of nine CJD patients, electrophoretic mobilities of three PrPres glycoforms were similar to type A, but the ratio of these glycoforms termed 'type B' was distinct from that of type A. On the other hand, one sporadic CJD case with wild-type PRNP had a different PrPres isoform termed type C, which showed higher molecular shift of each of the PrPres glycoforms. There was no significant relationships among genotypes, clinical features and PrPres isoforms in sporadic CJD cases. Our finding suggests that type A PrPres isoform is specifically found in the patients with GSS carrying codon 102 mutation, and there are at least two different PrPres isoforms in the patients with sporadic CJD.

Amyloid↗

New rubber-band loader to facilitate use of hemorrhoid ligator.

The placement of rubber bands on a ligator is often difficult and frustrating, especially when the operator is wearing gloves. A newly designed rubber-band loader with grooves and a pusher places the bands on the ligator easily, simultaneously, and quickly even under these conditions.

Hemorrhoids↗

Accumulation of class I mutant p53 and apoptosis induced by carboplatin in a human glioma cell line.

Following DNA damage, wild-type p53 increases and mediates the multiple cellular responses for the repair of DNA damage or apoptosis. Inactivation of p53 by single-amino-acid substitutions contributes to the malignant phenotype and confers resistance to therapy. Among tumor-derived p53 mutants, class I mutants still retain a native-like three-dimensional structure, whereas class II mutants have unfolded DNA-binding domains. Sequencing analysis demonstrated that a human glioma cell line (U-373MG) had only a class I mutant form of p53 of His273, which targets an Arg273 that contacts DNA but retains the native structure. In this study, we investigated the metabolic alteration of the class I mutant p53 in apoptosis of U-373MG. The cell cycle progression of U-373MG cells was affected by the addition of carboplatin, while the amount of mutant p53 also increased in their nuclei. The treated cells underwent apoptosis 48h after exposure to 50 microg/ml carboplatin. Although the exact mechanism of the class I mutant p53 in the process of apoptosis has not yet been clarified, the fact that accumulation of the activated mutant p53 in the nucleus of U-373MG is concomitant with apoptosis, just as wild-type p53 does, implies that the class I mutant p53 might retain the ability to participate in apoptosis.

Antigens, Nuclear↗

Skein-like inclusions in the neostriatum from a case of amyotrophic lateral sclerosis with dementia.

Skeins or skein-like inclusions (SLIs) in motor neurons detected by ubiquitin immunohistochemistry are a characteristic finding of amyotrophic lateral sclerosis (ALS). Here we report ubiquitinated SLIs in the putamen and caudate nucleus from a case of ALS with dementia. A 48-year-old Japanese man developed apathy and amimia. Mental and neurological examinations revealed severe character change, muscle atrophy and fasciculation of the distal upper extremities and the tongue, and an exaggeration of the deep tendon reflex. He subsequently showed dysphagia and dysarthria. He died at the age of 51 years, after a total clinical course of about 2.5 years. By immunohistochemistry, ubiquitin-immunoreactive intraneuronal inclusions were observed in the spinal anterior horn cells, the frontal, temporal and entorhinal cortices, dentate fascia of the hippocampus and the amygdala. In addition, ubiquitinated inclusions were also seen in the putamen and caudate nucleus, which appeared as aggregates of thread-like structures similar to SLIs in the spinal anterior horn neurons. They were not seen on hematoxylin-eosin staining, and they also did not show any argentophilia nor did they react with other antibodies, including antibody against tau protein. To our knowledge, this is the first report of the presence of SLIs in non-motor neurons. Our results thus support the notion that ALS is a multisystem disease, and not simply a disease of the motor neurons.

Amyotrophic Lateral Sclerosis↗

Differential expression of transforming growth factor-beta isoforms in human prion diseases.

To examine the involvement of transforming growth factor-beta (TGF-beta) in the pathogenesis of prion diseases, immunohistochemical studies on both TGF-beta isoforms (beta 1, beta 2 and beta 3) and TGF-beta receptor type II (TGF-beta RII) were performed on the cerebral neocortices of 20 cases with human prion diseases, three cases with Alzheimer's disease, and five control cases. TGF-beta 2 immunoreactivity was thus detected in most neurons and astrocytes in all observed cases of prion disease. TGF-beta 3 immunoreactivity in the astrocytes and TGF-beta RII in the neurons were also detected in 17 of 20 cases with prion diseases. These immunoreactivities had increased markedly regarding the intensity and the number of positive cells in comparison to the control cases, but they were indistinguishable from those observed in Alzheimer's disease cases. In contrast, the TGF-beta 1 immunostaining did not show any apparent difference. Among the cases with prion diseases, however, no significant correlation was revealed between the immunohistochemical results and the clinical and pathological features. The results showed that TGF-beta isoforms thus appear to be differentially involved in the pathogenesis of prion diseases in a similar manner to that of Alzheimer's disease. Furthermore, two cases of prion disease in which pathological findings were free from astrogliosis and neuronal cell degeneration in the cerebral cortices also showed an increased immunoreactivity for TGF-beta 2. Thus, this result suggests that TGF-beta 2 may be involved in the early stages of neuronal cell degeneration in prion diseases.

Adult↗