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Biomedical subjects

Y Hashizume

Publications and source records attributed to Y Hashizume.

At least 145 records · Page 8Linked to original sources
PubMed1993

Oxygen radical scavengers and renal protection by indapamide diuretic in salt-induced hypertension of Dahl strain rats.

In addition to the hemodynamic components, the roles of various humoral factors have been emphasized in the progression of vascular and renal injury in hypertension. Radical scavenging properties have attracted much attention in this field. This article discusses the implication of antioxidant properties of the antihypertensive diuretic indapamide on renal injury in Dahl salt-sensitive (Dahl S) rats. Hydroxyl radicals, oxygen radicals toxic to cellular membranes, are eradicated by indapamide in different assay systems, e.g., reduction of alpha-alpha-diphenyl-beta-picrylhydrazyl, rat brain homogenate, or xanthine-xanthine oxidase systems. Such antioxidant effects of indapamide are primarily due to inhibition of lipid peroxidation induced by hydroxyl radicals, and this mechanism may stimulate prostacyclin generation through activation of prostacyclin synthase. In fact, the antioxidant properties of indapamide are well expressed in vivo as well; indapamide treatment reduced oxygen radicals in the kidney of Dahl S rats with hypertension. This was accompanied by a functional improvement of the kidney; decreases in urinary protein and n-acetylglucosaminidase excretion and an increase in glomerular filtration rate were observed. In addition, indapamide morphologically ameliorated the renal injury, and decreased glomerular sclerosis score, arterial injury, and renal tubular injury. Trichloromethiazide reduces blood pressure similar to that produced by indapamide. However, trichloromethiazide did not lead to reduction of oxygen radicals in the kidney, and did not improve the functional disturbance or morphological injury seen in Dahl S rats. These results indicate that indapamide has antioxidant properties, and in addition to blood pressure reduction, such radical scavenging effects may contribute to its beneficial effects on renal function in vivo.

Animals↗
PubMed1993

A clinico-neuropathological study on brain death.

A clinico-neuropathological study was conducted on 60 cases of brain death, 36 males and 24 females, ranging in age from 11 to 81 years, the average being 49.4 years. Of these, 29 patients died of cerebrovascular disease. The average duration of brain death was 99 hours. The mean weight of the brain was 1466 g. Neuropathological findings were brain edema, congestion, herniation and various subarachnoid hemorrhages. Histologically, the cytoplasm of neurons was pale and ghost-like. In the white matter, myelin staining was pale, and nuclei of the glial cells were shrunken and piknotic. Autolysis of the cerebellar granular layer and the pituitary gland was evident in all cases. No reactive astrocytosis or infiltration of the cells in or around necrotic tissue could be seen. In eight cases, there was laminar infiltration of neutrophils in the superficial area of the cerebrum and brain stem, possibly due to temporary or partial recirculation. Correlation between the degree of autolysis and duration of brain death was observed, but no relationship between the degree of autolysis and the difference of underlying disease could be found. Autolysis in the cerebral cortex, thalamus, tegmentum of the brain stem, cerebellar granular layer and pituitary gland was most prominent. However, neuropathological diagnosis of underlying diseases could be made even in brain death. Histologically, the cases of brain death differed from those of cardiac arrest-induced encephalopathy and from those of long postmortem autopsy.

Adolescent↗
PubMed1993

[A case of tuberculous meningitis with abnormal contrast enhancement of choroid plexus on CT and MRI].

A 55-year-old man first noted a swelling on his back in September 1990, when CT scan of his chest suggested a pleural fistula and a cold abscess. In the following month, he became pyrexial and felt nauseated with headache. Subsequently he was transferred to our hospital. Results of neurological examination were abnormal only in that he had neck stiffness and bilateral nystagmus with drowsiness. Cerebrospinal fluid (CSF) showed turbid yellowish fluid with an opening pressure of 360 mmH2O, a protein content of 173 mg/dl, a glucose level of 19 mg/dl, and a white blood cell count of 3,024/ml (75% polymorphs, 25% lymphocytes). Tryptophane test was positive. No bacteria, fungi or acid-fast bacilli were seen on direct smear. Adenosine deaminase activity in CSF was 13.9 IU/l. Antibiotics, antituberculous drugs, corticosteroids and glycerol were administered. The clinical course in the hospital was satisfactory for the next two months, but a contrast enhanced CT scan showed prominent enhancement in the left choroid plexus, and MRI revealed another mass in the subarachnoidal space under the right frontal lobe. An open biopsy was done on the massive lesion in the frontal lobe. Macroscopically, this lesion was an encapsulated granulomatous one. On the other hand, there were groups of epitheloid cells with micronecrosis in their centers microscopically. These findings were compatible with tuberculoma, in spite of the absence of acid-fast bacilli or caseous necrosis. Medication was intensively continued: a follow-up CT showed gradual reduction of the choroid plexus lesion and shrinkage of the left lateral ventricle.

Choroid Plexus↗
PubMed1993

[Clinical and pathological study of myelopathy accompanied with cervical spinal canal stenosis--with special reference to complication of mental retardation or cerebral palsy].

We studied 3 cases with myelopathy caused by cervical spinal canal stenosis (developmental), who had been suffering from walking difficulty followed by tetraplegia, clinically and pathologically. In all 3 cases, mental retardation and/or cerebral palsy was diagnosed. We hypothesized that the brain damage in the developmental stage might also cause developmental disturbance in the cervical spine. In all cases, pathological investigation showed decreased antero-posterior diameter and degeneration in the gray matter and in the lateral and posterior column in the involved cervical spinal cord. The findings, such as relative preservation of the anterior column and cyst formation in the gray matter, were thought to be in common with cervical spondylotic myelopathy or ossification of the occipital longitudinal ligament (OPLL) which had been reported before. In one case we found aberrant peripheral nerve bundles and peripheral type remyelination in the transverse spinal cord lesion. Compared to the pathological change in the OPLL, our cases showed more severe degenerative change in the spinal segments with a relatively preserved antero-posterior diameter of the spinal cord, which supports the theory that the dynamic factor plays a more important role than the static compression factor. We concluded that the aging process and/or dystonic neck movement added spondylotic change to the narrow canal, and excess movement of the neck and/or falls caused dynamic injury to the spinal cord and secondary circulatory disturbance further worsened spinal lesions. When elderly patients with cerebral palsy develop motor symptoms, we should consider cervical spinal stenosis as a possible cause.

Aged↗
PubMed1993

[A neuropathological study on respirator brain].

A neuropathological study was conducted on 101 respirator brains. The patients comprised 62 men and 39 women, ranging in age from 11 to 84 years, the average being 49.4 years. Of these, 51 cases died of cerebrovascular disease, including 26 cases of subarachnoid hemorrhage. The average duration of mechanical supportive care was 99 hours. The mean weight of the brain at autopsy was 1,460 g. Characteristic pathological findings were brain edema, congestion, herniation and various subarachnoid hemorrhages. Brain consistency was soft despite adequate fixation. Histologically, the cytoplasm of neurons in the cerebral cortex, basal ganglia, cerebellum and brain stem was pale and ghost like. In the white matter, myelin staining was quite pale and nuclei of the glial cells were shrunken and piknotic. Autolysis of the granular layer of the cerebellar cortex and necrosis of anterior parts of the pituitary gland were evident in all of the brains examined. There were no reactive astrocytosis and no infiltration neutrophils in the superficial areas of the cerebrum and brain stem, possibly due to temporary or partial circulation. There exists some correlation between the degree of autolysis and the duration of artificial aeration. But no relationship between the former and the basic disease was found. In the respirator brains, autolysis was most prominent in the cerebral cortex, thalamus, tegmentum of the brain stem, granular layer of the cerebellar cortex and the pituitary gland. It was possible to establish the diagnoses of underlying diseases such as cerebrovascular disease, meningoencephalitis, tumor and degenerative disease in the majority of cases through neuropathological analysis on the respiratory brains.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[An adult case of classical Pelizaeus-Merzbacher disease--magnetic resonance images and neuropathological findings].

A 26-year-old man was first noticed to have slowly progressive difficulty in walking and speaking at the age of 19 years. When he was 26 years old, a neurological examination showed mild dementia, nystagmus, ataxic speech together with ataxic and spastic gait. The T2-weighted MR images demonstrated increased signal areas with sparing of small areas in the brain white matter. He expired suddenly at his age of 26 years. The neuropathological study revealed the mildly atrophic brain with "tigroid" demyelination. Patchy demyelinated foci were found in the cerebellum, brain stem and spinal cord. The myelin around blood vessels and axons were generally well preserved. Oligodendrocytes were decreased in the demyelinated areas. A diagnosis of classical Pelizaeus-Merzbacher disease was neuropathologically made, in spite of uncertainty of family history and late onset. Because MR images are identical with the neuropathological findings of "tigroid pattern", MR imaging can contribute to the clinical diagnosis of this disease. This is the first report in which brain MR images are compared with neuropathological findings in a case of classical P-M disease.

Adult↗
PubMed1993

[A pathological study of basilar artery sclerosis resulting from vertebral artery asymmetry].

We conducted a pathological study of the arteries of Willis ring in 130 autopsied specimens to evaluate the influence of vertebral artery (VA) asymmetry on basilar artery (BA) sclerosis. The cases studied comprised 109 of non-brainstem infarction (control) and 21 of thrombotic basilar artery occlusion (BAO). The frequency of VA asymmetry was significantly higher (p < 0.01) in BAO cases (13 out of 21 cases; 61.9%) than in the controls (35 out of 109; 32.1%). In the controls, the mean scores for stenosis of the caudal (p < 0.01) BA were significantly higher in VA asymmetry pattern than in VA normal pattern, but the mean score of the rostral BA was nearly equal in both patterns. In BAO cases with VA asymmetry, the score for stenosis was higher in the caudal portion than in the rostral portion, and occlusion was frequently found in the lower BA and continuing from the thicker VA to the BA. These findings suggest that atherosclerotic changes may occur more preferentially in the lower BA in cases of VA asymmetry, and that VA asymmetry is considered to be one of the risk factors for BA occlusion.

Adult↗
PubMed1992

Basophilic inclusions in sporadic juvenile amyotrophic lateral sclerosis: an immunocytochemical and ultrastructural study.

This report concerns immunocytochemical and ultrastructural studies on the basophilic inclusions in two cases of sporadic juvenile amyotrophic lateral sclerosis (ALS). The inclusion had a globular, irregular-shaped, or sometimes fragmented appearance. Ultra-structurally, the inclusions consisted mainly of thick filamentous structures associated with granules. Focal neurofilamentous accumulations were occasionally observed among the granulofilamentous structures. The basophilic inclusions occasionally showed granular reaction product deposits with an antibody to ubiquitin. The inclusions did not react with antibodies to phosphorylated neurofilament and to tau protein.

Adult↗
PubMed1992

Ubiquitin-positive intraneuronal inclusions in the extramotor cortices of presenile dementia patients with motor neuron disease.

Ubiquitin-positive intraneuronal inclusions were found in the extramotor cortices of ten presenile dementia patients with motor neuron disease. There were inclusions in the hippocampal granular cells and in the small neurons of the superficial layers of the temporal and frontal cortices. Bunina bodies were present in the anterior horn cells in all cases. These results suggest that ubiquitin-related cytoskeletal abnormalities are common in cerebral non-motor small neurons in these patients.

Adult↗
PubMed1992

Somatic motor efferents in multiple system atrophy with autonomic failure: a clinico-pathological study.

The myelinated fibers in the corticospinal tracts, ventral spinal roots, and the neurons in the ventral spinal horns were quantitatively examined in 8 autopsied cases of multiple system atrophy associated with autonomic failure. In these structures consisting of the somatic motor efferents, the main pathological feature was the size dependent-involvement of predominantly small-sized fibers and neurons. The small myelinated fibers were significantly depopulated, while the large myelinated fibers were well populated in the corticospinal tract. Neurons in the ventral horns were also involved, but those with a small diameter and located in the intermediate zone (Rexed's lamina VII, VIII) were markedly diminished. In the ventral spinal roots, in the fourth lumbar segments containing essentially no autonomic efferents, small myelinated fibers were also preferentially involved. These pathological changes in the small-sized fiber and neuron loss were examined in relation to the somatic and autonomic motor symptoms, particularly of pyramidal signs.

Aged↗
PubMed1992

Tethered cord syndrome: cause for urge incontinence and pain in lower extremities.

An eight-year-old girl has had urge incontinence for the last three years and muscle weakness and pain in the lower extremities for one month. Urodynamic study revealed a bladder instability of severe degree. Tethered cord syndrome caused by a tight filum terminale was identified by metrizamide myelography. An untethering of the filum terminale resolved her symptomatology completely. The urologist should be aware of this syndrome in a patient presenting with incontinence that has persisted for a long time or has recurred.

Cauda Equina↗
PubMed1992

Pathology of spinal cord lesions caused by ossification of the posterior longitudinal ligament, with special reference to reversibility of the spinal cord lesion.

This report describes pathological findings of the spinal cord damage, with ossification of the posterior longitudinal ligament (OPLL), with special reference to reversibility of such lesions. Twenty-five autopsy cases associated with OPLL were examined, and the spinal cord damage was pathologically classified into four categories based on degree of destruction (stage 0-3). In stage 0 and stage 1, major pathological changes in the gray matter and the degree of compression on the spinal cord were well correlated to deformity of the anterior horn. In stage 2 and stage 3, neurons were almost completely obliterated and necrosis with cavitation were frequently observed. Destruction of the spinal cord in stage 2 and stage 3 is considered to be irreversible; therefore, surgical treatment is recommended at stage 0 or stage 1.

Calcinosis↗
PubMed1992

Histopathologic and morphometric study of spinal cord lesion in a chronic cord compression model using bone morphogenetic protein in rabbits.

Chronic compressive myelopathy was induced in domestic rabbits by implanting bone morphogenetic protein on the ligamentum flavum of the lumbar spine, and the resulting spinal cord lesion was studied histopathologically. In addition, morphometry of myelinated nerve fibers of the white matter in the pathologic specimens was performed to elucidate the mechanisms of cord injury. No loss of white matter nerve fibers was seen when the cord compression ratio (sagittal diameter/transverse diameter) was > 45%, although 6 months later myelin thinning was present throughout the white matter. When the cord compression ratio was < or = 45%, loss of fibers, particularly of large fibers, was seen in the superficial layer of the white matter, with the nerve fibers remaining after 6 months showing decreased diameters. No motor paresis was evident in any animal. These histologic changes represent the early pathologic condition induced by chronic cord compression.

Animals↗
PubMed1992

Dural arteriovenous malformation and sinus thromboses in a patient with prostate cancer: an autopsy case.

A 67-year old man with prostate cancer showed Balint's syndrome, memory disturbance, anosognosia and hallucinations after having been comatose. Radiological findings indicated bilateral dural arteriovenous malformation (DAVM) and thrombosis at the bilateral transverse sinuses and superior sagittal sinus. Pathological findings showed abnormally dilated veins, diffuse neuron loss and gliosis in the parieto-occipital lobe. The chlormadinone and prostate cancer are speculated to have caused the dural sinus thrombosis which probably induced the DAVM.

Adenocarcinoma↗
PubMed1992

[Bedridden elderly and dementia].

The purpose of this study is to clarify possible correlations between dementia and long term bedridden elderly patients in our special nursing home and geriatric hospital. At the time of our study, 42.6% of all our patients were bedridden, and the ratio increased in those groups of advanced age. The percentage of bedridden female patients was higher than that of males. Most bedridden patients, suffered disorders of the nervous system particularly disorders caused by cerebrovascular disease. Among the bedridden patients, the incidence of dementia was 82.8%. In most these cases, the degree of dementia was severe. The types and respective percentages of dementia were as follows: Vascular type 45.1%, Alzheimer's type 23.2%, mixed type 19.5% and others 12.2%. We think that Alzheimer's type dementia may cause a patient to become bedridden. On the other hand, vascular type dementia may be promoted by a patient's being bedridden for a long time. Tube-fed patients comprised 20% of all bedridden patients and all of these patients showed dementia. We believe that a patient's getting out of bed and receiving rehabilitation as soon as possible is vital to the prevention of becoming permanently bedridden. In respect to the present study of bedridden dementia patients, we would like to further study tube feeding and terminal care.

Aged↗
PubMed1992

[Five year follow-up study on dementia in institutions for the elderly].

The purpose of this study was to clarify the prognosis of senile dementia based on a 5-year follow-up study in institutions for the elderly. The subjects consisted of 747 cases over 60 years of age. Of these 316 cases showed clinical dementia but 431 cases had no intellectual disturbance in July, 1987. The mortality rate (56.3%) of the demented group was significantly higher than that (31.8%) of the non-demented group. The mortality rate of patients increased with aging. However, the mortality rate of the demented group did not correlate with the severity of dementia. An autopsy study revealed that the direct causes of death in 51.1% of demented patients were pneumonia and cardiovascular diseases. Among the demented patients followed up for 5 years, 22.5% showed severe worsening of dementia, 25.8% showed slight or moderate degree of worsening and 51.7% showed no change. Factors causing exacerbation of dementia included cerebrovascular disease and bone fracture.

Aged↗
PubMed1992

[Intellectual ability and activity of daily living of centenarians in institutions for the elderly].

The purpose of this study was to assess the intellectual ability and activity of daily living (ADL) of 12 centenarians in institutions for the elderly and to compare them with individuals in the 62-99 age group. At the time of our study, 66.7% of the centenarians were severely demented, three quarters of them suffering from Alzheimer's type dementia and the other one quarter the mixed type. There were qualitative differences between non-demented centenarians and the demented elderly in general, particularly in regard to understanding of surrounding objects and the presence or absence of mental symptoms indicating intellectual deterioration. A total of 50% of the centenarians were bedridden, but 41.7% of them could eat without assistance. Intellectual ability and ADL directly decreased with aging. We think centenarians do not present a special case and our clinical observations suggest a continuous process of aging. Five of the centenarians recently died and were autopsied. The agreement rate between clinical diagnoses and pathological findings with respect to dementia was 80%.

Activities of Daily Living↗