Search PubMed⌕ Search

Biomedical subjects

T Iwaki

Publications and source records attributed to T Iwaki.

At least 37 records · Page 2Linked to original sources
PubMed2001

Spinal cord lesions of myelitis with hyperIgEemia and mite antigen specific IgE (atopic myelitis) manifest eosinophilic inflammation.

We report the neuropathological findings of spinal cord specimens obtained from two patients who had localized myelitis with hyperIgEemia and mite antigen specific IgE (atopic myelitis). Both cases showed mild spinal cord dysfunction, and the gadolinium-enhanced area of the isolated spinal cord lesion observed on MRI was biopsied, respectively. Neuropathologically, both cases showed many perivascular lymphocyte cuffings associated with disrupted vessels, and the infiltration of eosinophils in the spinal cord lesions. Both myelin and axons were lost in the lesions, which were associated with astrogliosis. These findings suggest that an allergic mechanism may play a role in this condition.

Adult↗
PubMed2001

Cloning of glycerol-3-phosphate dehydrogenase genes (ZrGPD1 and ZrGPD2) and glycerol dehydrogenase genes (ZrGCY1 and ZrGCY2) from the salt-tolerant yeast Zygosaccharomyces rouxii.

The ZrGPD1 and ZrGPD2 genes encoding putative glycerol-3-phosphate dehydrogenases were isolated from the salt-tolerant yeast, Zygosaccharomyces rouxii. Both genes are homologous to GPD1 of Saccharomyces cerevisiae and are constitutively expressed in Z. rouxii cells. Putative glycerol dehydrogenase genes, ZrGCY1 and ZrGCY2, which are highly homologous to GCY1 of S. cerevisiae, were also isolated. Since the level of transcripts of ZrGCY1 and ZrGCY2 increased in Z. rouxii cells subjected to salt stress, it is suggested that the pathway of the signal transduction of salt stress controls the expression of these genes. The Accession Nos of these sequences in GenBank are as follows: ZrGPD1, AB047394; ZrGPD2, AB047395; ZrGCY1, AB047396; ZrGCY2, AB047397.

Amino Acid Sequence↗
PubMed2001

Different responses of benign and atypical meningiomas to gamma-knife radiosurgery: report of two cases with immunohistochemical analysis.

Recent reports have shown that gamma-knife radiosurgery provides a safe and effective strategy for the management of brain tumors. To evaluate the role of stereotactic radiosurgery in the management of meningiomas, we investigated the histopathology of two patients. The patients, a 37-year-old man and a 54-year-old woman, presented with visual field disturbance or headache. Imaging studies demonstrated intracranial meningiomas--tentorial and sphenoid ridge, respectively. Each patient undewent subtotal surgical resection (more than 90% in both patients), followed by gamma-knife radiosurgery of the remnant tumor marginal doses of 15 Gy. Pathological examination of the original tumors revealed a meningothelial meningioma and an atypical meningioma, respectively. Enlargement of the remnant tumors 4 months after radiosurgery resulted in total surgical resection in both patients. Thirteen months later, the patient with the atypical meningioma underwent a third operation for early recurrence of the tumor. Histopathology was investigated, and MIB-1, p53, and bcl-2 labeling indexes (LI) were analyzed immunohistochemically. Histopathologically, the specimens showed necrosis and intratumoral vessel obliteration after radiosurgery in both cases. However, more remnant tumor cells survived in the atypical meningioma. Immunohistochemically, increased wild-type p53, decreased bcl-2 expression, and decreased MIB-1 LI were observed in the benign meningioma. In the atypical meningioma, on the contrary, MIB-1 LI was decreased and mutant-type p53 and bcl-2 expression were unchanged. The specimen from the third operation revealed an anaplastic meningioma, and MIB-1 LI was markedly increased. These findings suggest that the efficacy of radiosurgery may differ between benign and atypical meningiomas.

Adult↗
PubMed2001

Different forms of dizziness occurring after cochlear implant.

Dizziness after cochlear implant (CI) was studied in a series of 94 consecutive adult patients receiving a cochlear implant, 46 (49.0%) of whom experienced dizziness post-operatively. In 29 patients, post-operative dizziness occurred soon after surgery and subsided within one month. Dizziness of the continuous type, lasting more than 6 months, was a complaint in only two patients. In addition to these already known forms of dizziness, spells of vertigo occurring later than one month after cochlear implant were experienced by 15 patients (delayed-V). The spells of delayed-V occurred suddenly and persisted for several hours. Moreover, 85.7% of delayed-V patients complained of hearing and tinnitus abnormalities during these spells. The clinical features of delayed-V were similar to those in patients with Meniere's disease. The preoperative bithermal caloric test showed a significantly higher response for the delayed-V group than the other groups (ANOVA: P < 0.05) in terms of slow phase eye velocity of caloric nystagmus. These findings suggest that inner ear lesions due to cochlear implant surgery develop gradually. Similarities in clinical features between delayed-V and Ménière's disease indicate the presence of labyrinthine hydrops.

Adolescent↗
PubMed2001

Expression of the lysosome-associated membrane proteins in myopathies with rimmed vacuoles.

Lysosome-associated membrane proteins (LAMPs) are structural glycoproteins located on the lysosomal membrane and are thought to have an important role in protein degradation. Increased lysosomal activity is associated with the formation of rimmed vacuoles, which are observed in various muscle disorders such as inclusion body myositis (IBM) and distal myopathy with rimmed vacuole (DMRV). In the present study, we examined LAMP-1 and LAMP-2 in biopsied muscle specimens from four cases of sporadic IBM and two of DMRV, as well as six of myopathies without rimmed vacuoles. In all cases of IBM and DMRV, immunohistochemistry showed accumulation of LAMPs in the rimmed vacuoles and the subsarcolemmal portion of the vacuolated fibers. Immunoreactivities of LAMPs in the vacuolated fibers were often associated with those of cathepsin D; however, cathepsin D was not expressed on some LAMP-positive fibers. Further, atrophic muscle fibers were sometimes positive for LAMPs expression. These findings were more prominent in LAMP-2 than in LAMP-1. Thus, LAMP-2 may play an important role in the increased protein degradation in diseased muscle fibers. The increased expression of LAMPs in the vacuolated muscle fibers may be associated with the formation of rimmed vacuoles in IBM and DMRV.

Adult↗
PubMed2001

Cognitive dysfunction in patients with amyotrophic lateral sclerosis is associated with spherical or crescent-shaped ubiquitinated intraneuronal inclusions in the parahippocampal gyrus and amygdala, but not in the neostriatum.

Skeins or skein-like inclusions, one of the two types of ubiquitinated intraneuronal inclusions in amyotrophic lateral sclerosis (ALS), in the neostriatum are not specific to the disease, but it has not yet been determined whether the other, spherical or crescent-shaped inclusions (SCI) are pathognomonic. To clarify this and also to investigate whether the distribution of SCI in particular brain regions is associated with clinical parameters, we examined the occurrence of SCI in the brains of 24 patients with ALS and 94 controls. SCI in the neostriatum were specifically detected in 54% of the ALS cases, but not in any of the controls. No apparent phenotypic denominator, such as disease duration or the occurrence of dementia, correlated to the distribution of SCI in the neostriatum in ALS cases. On the other hand, the occurrence of SCI in both the second and third layers of the parahippocampal gyrus and amygdala was significantly correlated to the presence of dementia in ALS cases. SCI were distributed in association with each other among the parahippocampal gyrus, dentate gyrus of the hippocampus and amygdala, but not between the spinal anterior horn and any non-motor-associated brain regions. These findings suggest that these particular brain regions might be significantly involved in the neurodegenerative process associated with ALS. The relationship of SCI to either ALS pathogenesis or cognitive dysfunction depends on the brain regions in which they are distributed, and this indicates that the neurodegenerative processes in ALS proceed differentially in particular motor-associated and nonmotor-associated brain regions.

Aged↗
PubMed2001

The wound-healing effect of fibrin glue for tracheal anastomosis in experimental pulmonary surgery.

The leakage of tracheal anastomoses is one of the major complications that occurs after tracheal reconstruction. Improved reinforcing methods for anastomoses would thus be clinically useful. To find a better technique, we examined the postoperative would-healing effect of fibrin glue on tracheal anastomosis in the rat. Experimental rats were divided into two groups. In the control group (n = 21), the trachea was anastomosed by interrupted absorbable sutures. In the fibrin glue group (n = 21), the trachea was anastomosed in the same manner as the control group, with the addition of fibrin glue around the area of anastomosis. In the two groups, we studied the amount of hydroxyproline and histological findings on the seventh, 14th, and 21st postoperative day. The amount of hydroxyproline and collagen fibers in the fibrin glue group was more than in the control group on the seventh postoperative day. These results suggest that fibrin glue has a promotive effect in the healing of tracheal anastomosis.

Anastomosis, Surgical↗
PubMed2001

Multiple palisading granulomas in the scalp of an infant: a case report.

BACKGROUND: We describe an unusual lesion that represents an uncommon but important element in the differential diagnosis of subcutaneous scalp nodules in a child. CASE DESCRIPTION: A 1-year-old boy presented with two clusters of subcutaneous scalp nodules. The lesions increased in size and number. Computed tomography showed no changes in underlying bone. Findings on magnetic resonance imaging were nonspecific. Serologic and clinical evaluation showed no evidence of rheumatic disease. Complete excision of the nodules, together with adjacent fascia and galea, was performed. Histopathologic examination showed the lesions to be palisading granulomas; given the absence of rheumatic disease, these represented deep granuloma annulare, a benign condition. No recurrence has been observed in our patient. CONCLUSION: While we chose total excision because of preoperative concerns about a possible malignant tumor, some other authors have suggested that surgery be limited to confirmatory biopsy when a benign lesion such as palisading granuloma is strongly suspected.

Diagnosis, Differential↗
PubMed2001

Prostaglandin D synthase (beta-trace) in meningeal hemangiopericytoma.

The level of prostaglandin D synthase (PGDS), a major protein constituent of cerebrospinal fluid (CSF), is altered in various brain diseases, including meningitis. However, its role in the brain remains unclear. PGDS is mainly synthesized in the arachnoid cells, the choroid plexus and oligodendrocytes in the central nervous system. Among brain tumors, meningiomas showed intense immunoreactivity to PGDS in the perinuclear region. Thus, PGDS has been considered a specific cell marker of meningioma. In this study, we examined 25 meningeal hemangiopericytomas (HPCs) and found that 16 of the tumors (64%) showed immunoreactivity for PGDS in the perinuclear region. For comparison, 15 meningiomas, 14 soft-tissue HPCs, 1 mesenchymal chondrosarcoma, 3 choroid plexus papillomas, and 7 oligodendrogliomas were also examined. Meningiomas showed positive immunoreactivity for PGDS in 13 cases (80%). Except for one case located at the sacrum, none of the other soft-tissue HPCs showed immunostaining for PGDS. Mesenchymal chondrosarcoma arises in the bones of the skull, and its histological pattern resembles that of HPC; however, it showed no immunoreactivity for PGDS. Neither choroid plexus papillomas nor oligodendrogliomas were immunopositive for PGDS. These findings suggest that meningeal HPCs may have a unique molecular phenotype that is distinct from that of the soft-tissue HPCs. The origin of meningeal HPCs may be more closely related to the arachnoid cells.

Adolescent↗
PubMed2001

Autopsy case of autosomal recessive hereditary spastic paraplegia with reference to the muscular pathology.

An autopsied case of autosomal recessive hereditary spastic paraplegia with severe neurogenic muscular atrophy is described herein. This patient, a 16-year-old woman, presented with gait disturbance. She developed progressive spastic paralysis of the upper and lower limbs and mental deterioration. She became bedridden at approximately 40years of age. Dysarthria worsened at 45 years of age. She died of pneumonia at 50 years of age. Her younger sister has shown similar clinical symptoms and became bedridden at 37 years of age. Their parents were second cousins. Autopsy revealed a severely atrophic brain, weighing 720 g. The cerebral cortex was thin, and the white matter was extremely reduced in volume. Microscopically, neuronal loss and variable astrogliosis with diffuse spongy changes were evident at the cerebral cortex, thalamic nuclei, basal ganglia and hippocampus. The remaining neurons were atrophied with heavy deposition of lipofuscin. In the spinal cord, the pyramidal tracts as well as the dorsal spinocerebellar tracts were degenerated. In addition, marked loss of the anterior horn cells was seen. Severe neuronal loss of the nucleus gracilis was also detected. In contrast, only mild degeneration of the ventral spinocerebellar tracts and fasciulus cuneatus in the spinal cord were observed. In the frozen sections of skeletal muscle, severe neurogenic atrophy and fatty infiltration were evident. In addition, several rimmed vacuoles were observed in the atrophic fibers, and cytochrome coxidase-deficient fibers were present in part. Reduced nicotinamide adenine dinucleotide (NADH)-tetrazolium reductase reaction revealed abnormal accumulation of mitochondria around the center of the non-atrophic muscle fibers. It is suggested that an analysis of mitochondrial function of Japanese autosomal recessive hereditary spastic hemiplegia may provide additional information to clarify the pathogenesis.

ATPases Associated with Diverse Cellular Activitie↗
PubMed2001

An atypical case of sporadic Creutzfeldt-Jakob disease with Parkinson's disease.

We report here an autopsy case of a 64-year-old female with slowly progressive dementia and parkinsonism in a 4-year-long clinical course. Post-mortem examination revealed a severely atrophic brain with spongiform degeneration, neuronal loss and gliosis in the gray matter. Many prion protein plaque deposits were present in the occipital lobe, amygdala and cerebellum. Additionally, Lewy bodies were observed in the brainstem. Prion protein gene analysis of the patient revealed polymorphism at the codon-129 valine heterozygote. This genotype is known to sometimes accompany a missense mutation of the gene in uncommon hereditary prion diseases, but no mutation was found in the open reading frame. Thus, it might be suggested that this case showed simultaneously the features of both sporadic Creutzfeldt-Jakob disease (CJD) with codon-129 valine and Parkinson's disease. However, the predisposing factors for contracting both diseases simultaneously remain to be determined, because the incidence of Parkinson's disease accompanied by CJD is very low.

Aged↗
PubMed2001

Apoptotic bodies in the cerebellum of Japanese patients with Creutzfeldt-Jakob disease.

The aim of this study was to provide morphological evidence for neuronal apoptosis in Creutzfeldt-Jakob disease (CJD) using hematoxylin-eosin (HE)-stained specimens. A microscopic examination showed typical apoptotic bodies were found in the granular layer of the cerebellum in 13 of 14 Japanese patients with CJD, while no apoptotic bodies were observed in any other areas of the examined CJD brains. Most of the fragmented nuclei of the apoptotic cells were labeled by in situ end-labeling of fragmented DNA, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling. To the authors' knowledge, this is the first report demonstrating neuronal apoptotic bodies in the human neurodegenerative disorders on HE-stained sections. The present findings indicate that apoptosis plays a major role in the neuronal loss of the cerebellar granule cells in CJD.

Adult↗
PubMed2001

Pituitary tumours in adolescence: clinical behaviour and neuroimaging features of seven cases.

The clinicopathologic features of seven paediatric patients with pituitary adenomas (2 male, 5 female; mean age 14.3 years) were reviewed. There were three non-functioning adenomas, three prolactinomas, and one growth hormone producing adenoma. Five patients presented with visual field deficits, and six patients had endocrine symptoms, which included menstrual irregularities in all female patients, pubertal delay in two females, and growth delay and gigantism in one case each. On neuroimaging studies, five adenomas showed parasellar extension, while the remaining two prolactinomas were intrasellar microadenomas. While two patients with prolactinomas received good results with bromocriptine treatment alone, the remaining five patients underwent either craniotomy or transsphenoidal surgery. Postoperatively, visual disturbances improved markedly in all patients. Two patients also received replacement hormonal therapy. While six patients have been stable for 3.6 years on average, one non-functioning tumour recurred 2 years after the initial transcranial subtotal resection of the tumour. Although there are still many unknowns concerning the biology and optimal treatments for paediatric pituitary adenomas, many of them are assumed to be relatively rapidly growing tumours, while others merely have an earlier tumour genesis than in adults.

Adolescent↗
PubMed2001

Vascular endothelial growth factor in chronic subdural haematomas.

OBJECTIVE: To elucidate molecular aspects of the mechanisms of expansion of chronic subdural haematomas (CSH), we examined the expression of two representative angiogenic factors, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in CSH. METHODS: We quantified VEGF and bFGF in haematoma fluid and serum of 20 patients with CSH using an enzyme-linked immunosorbent assay. Mean concentrations of VEGF in the haematoma fluid (10277 pg/ml) and in serum, (355 pg/ml) were much greater than those of bFGF (haematoma, 3.04 pg/ml; serum, 4.74 pg/ml). Surgical specimens, including dura and the outer membrane of the CSH were analysed by in situ hybridisation to detect VEGF mRNA. Macrophages and vascular endothelial cells in the outer membrane over expressed VEGF mRNA. CONCLUSIONS: Enhanced production of VEGF by macrophages and vascular endothelial cells in the outer membrane is thought to be pathogenetically important in CSH.

Adult↗
PubMed2001

DNA sequence analysis of protein S deficiency--identification of four point mutations in twelve Japanese subjects.

The molecular basis for the hereditary type I protein S (PS) deficiency was investigated. DNA sequence analysis of 12 patients with PS deficiency in Japan identified four point mutations and three of them were novel. Nonsense mutations found in two unrelated patients resulted in termination of the PS polypeptide chains at Gln 238 and Lys 392, respectively. Two novel missense mutations were also found in two other patients substituting Asp 202 for Asn and Leu 298 for Pro, respectively. Comparison of the PS amino acid sequences from several mammalians indicated that Asp 202 and Leu 298 were preserved and thus appeared to be responsible for the pathogenesis of PS deficiency.

Humans↗
PubMed2001

Local cold stress to the soles induces retroplacental hemorrhage in rats.

The aim of this study was to investigate the effect of local cold stress to the soles on placental histology in rats. Pregnant rats were subjected to a cold provocation (0 degrees C, 12 degrees C) and room temperature (23 degrees C) for 15 and 30 minutes. During cold stimulation and at the control temperature, uterine blood flow and uterine contraction were measured simultaneously. Histological studies of the placentas of these rats were also performed. Cold stress at 0 degrees C and 12 degrees C significantly decreased uterine blood flow (P < .005, P < .02) compared with controls (23 degrees C). The decrease in uterine blood flow was greater at 0 degrees C than at 12 degrees C stress. Cold-induced stress (0 degrees C) also evoked an isometric tension with increased frequency and amplitude in the rat uterus (P < .003, P < .0002) compared with controls (23 degrees C). Stimulation at 12 degrees C did not induce any uterine contractions. Placental histology of rats stressed at 0 degreesC revealed hemorrhages into the decidua basalis. These findings suggest that local cold stress decreases uterine blood flow and increases uterine contraction, resulting in retroplacental hemorrhage in rats. This model may account for human abruptio placentae.

Animals↗