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Biomedical subjects

N Iwamoto

Publications and source records attributed to N Iwamoto.

At least 91 records · Page 5Linked to original sources
PubMed1992

Neurotrophic factor-like effect of FPF1070 on septal cholinergic neurons after transections of fimbria-fornix in the rat brain.

FPF1070 is an aqueous protein-free solution, which consists of 85% free amino acids and 15% small peptides. Our previous study showed a potent neurotrophic factor-like activity in cultured embryonic cells of dorsal root ganglia. The present study investigated whether FPF1070 regenerated the cholinergic cells in the medial septal nucleus after axonal transections by cutting the fimbria-fornix. Fimbrial transection reduced the number of septal cholinergic cells by 30 +/- 3.6%, compared with the number on contralateral sides at 4 weeks. Intraperitoneal injections of FPF1070 caused 49.9 +/- 6.3% of the cholinergic neurons to survive. Furthermore, the cell sizes of the cholinergic neurons were significantly different: 16.4 +/- 4.2 microns, 14.3 +/- 3.8 microns in FPF1070 treatment and vehicle treatment, respectively. These results indicated that FPF1070 prevents the degeneration and atrophy of impaired cholinergic neurons by systemic administration.

Amino Acids↗
PubMed1991

Localization of calpain immunoreactivity in senile plaques and in neurones undergoing neurofibrillary degeneration in Alzheimer's disease.

An antibody raised against the calcium activated neutral protease (calpain) was used to investigate the possible involvement of this enzyme in the formation of plaques and tangles in Alzheimer-type dementia (ATD) brain. Our results revealed the presence of a number of strongly stained calpain positive neurones in the normal human cerebral cortex and a loss of calpain positive cells in ATD brain. Furthermore, double staining experiments revealed that calpain immunoreactivity was present in cells undergoing tangle formation, and was also present in senile plaques. These data suggest that activation of calpain may be an important factor in the abnormal proteolysis underlying the accumulation of plaques and tangles in ATD.

Aged↗
PubMed1991

Demonstration of neurofibrillary tangles in parvalbumin-immunoreactive interneurones in the cerebral cortex of Alzheimer-type dementia brain.

The pathological changes occurring in a population of parvalbumin-like immunoreactive cerebral cortical interneurones in postmortem Alzheimer-type dementia brain tissue were determined by double staining cerebral cortical sections for parvalbumin, tau and/or calpain-like immunoreactivities. By counting the number of double immunostained cells it was determined that 4% parvalbumin and 25% of calpain-like immunoreactive cells showed evidence of tau-like immunoreactivity, indicative of neurofibrillary tangles. These results suggest that cerebral cortical parvalbumin-like immunoreactive neurones are relatively resistant to the pathological changes underlying the formation of neurofibrillary tangles associated with Alzheimer-type dementia.

Alzheimer Disease↗
PubMed1991

The significance of cerebrovascular amyloid in the aetiology of superficial (lobar) cerebral haemorrhage and its incidence in the elderly population.

Cerebrovascular amyloid deposition (CVAD), caused by deposition of the beta/A4 protein, has been previously identified as a cause of cerebral haemorrhage, yet its prevalence is uncertain. The presence of vascular amyloid was studied in brains of 169 patients by immunohistochemical and Congo red staining. Fifty patients had cerebral haemorrhage (CH), 56 had cerebral infarction (CI), and 63 had neither haemorrhage nor infarction (control group). CVAD was found in 38 per cent of the CH group, 25 per cent of the CI group, and 32 per cent of the control group. The incidence of CVAD increased with age in each group. Immunohistochemical staining with an antibody to beta/A4 protein was more sensitive than Congo red staining the demonstrating the extent of vascular amyloid. Within the CH group, CVAD was present in the vessels at the site of haemorrhage in 6/8 (75 per cent) of pure superficial (lobar) cerebral haemorrhages. While amyloid was detected in vessels in the brain of 10/37 (27 per cent) of pure deep cerebral haemorrhages, none was present in vessels at the site of haemorrhage. CVAD is a common pathological finding in the elderly and has a significant association with pure superficial (lobar) cerebral haemorrhages.

Aged↗
PubMed1990

Cell membrane changes in brains manifesting senile plaques: an immunohistochemical study of GM1 membranous ganglioside.

To investigate structural changes in cell membranes of the Alzheimer-type dementia (ATD) brain, we immunostained for GM1 ganglioside which is a major component of the cell membrane. Our results have shown that astrocytic membranes and senile plaques (SPs) have the same immunoreactivity against the monoclonal anti-ganglioside GM1 antibody. Moreover, the astrocytic processes within the SPs were altered and their abnormal membranes seemed to contribute to the formation of SPs.

Aged↗
PubMed1990

Two cases of parathyroid carcinoma in patients on long-term hemodialysis.

Two cases of parathyroid carcinoma, in a 46-year-old male on maintenance hemodialysis for 135 months and a 55-year-old female on maintenance hemodialysis for 64 months were reported. In both cases, the parathyroid carcinoma showed local invasion and the other glands were hyperplasia and/or adenoma, which would support the concept of malignant transformation occurring in parathyroid hyperplasia. The concurrence of parathyroid carcinoma with hyperplasia and/or adenoma is a pertinent feature in patients on maintenance dialysis, although it is rare in primary parathyroid carcinoma.

Female↗
PubMed1990

[Rapid measurement of human parathyroid hormone-(1-84) by immunoradiometric assay for use in intraoperative determination of hyperfunctioning parathyroid glands].

Rapid measurement of serum intact parathyroid hormone concentration was achieved by modification of an immunoradiometric assay for the hormone. Incubation of serum samples for 15 min at 37 degrees C under shaking gave optimal results in terms of assay variance and reproducibility: intra-assay CVs were less than 10% over the hormone concentrations of 11-1,600 pg/ml; intra- and inter-assay CVs for two control sera at different hormone levels were less than 12%. The minimal detectable hormone concentration was found at 27.8 pg/ml. The serum hormone levels of 43 subjects (31 health subjects, 9 patients with primary hyperparathyroidism, and 3 patients with secondary hyperparathyroidism) determined by either rapid or regular assay well correlated with each other (r2 = 0.979, p less than 0.001). In two patients with parathyroid adenoma serum intact PTH levels fell rapidly to 12.1% of the preoperative values 20 min after ligation of the vascular pedicle to the hyperfunctioning glands. We conclude that the modified assay protocol allows rapid, accurate, and simple estimation of intact PTH concentrations, and can be used as an intraoperative measure to aid both diagnosis and surgical cure of hyperparathyroidism.

Chi-Square Distribution↗
PubMed1989

The formation of prostaglandins in the postmortem cerebral cortex of Alzheimer-type dementia patients.

The formation of arachidonic acid metabolites [prostaglandin (PG)D2, PGE2, PGF2 alpha, 6oxo-PGF1 alpha and thromboxane (TX)B2] has been examined in the frontal, temporal, and parieto-occipital regions of the cortex in the postmortem brains from five patients with a pathologically verified Alzheimer-type dementia (ATD) and in eight, age-matched controls. The study disclosed that the amount of PGD2 and TXB2 found in the ATD brains was greater than in controls, and that the formation of PGD2 was significantly increased in the frontal cortex of the ATD brains. Other PG metabolites, however, showed no significant changes in the ATD group. Since it is known that PGD2 is synthesized mainly in neurons, our results seem to suggest that the preserved cortical neurons in the ATD brain have an accelerated PGD2 production.

Aged↗
PubMed1987

[Blood access puncture point pseudoaneurysms in two hemodialysis patients].

This is a report of blood access puncture point pseudoaneurysms which occurred in two hemodialysis patients. Case 1: A 58-year-old male had been undergoing hemodialysis treatment since June, 1975. In January, 1981 a subcutaneous mass had developed at the blood access puncture point above the previously superficialized left femoral artery. An operation was performed in February, 1981 and the mass was dissected. The same artery has been used since the operation for blood access without any problems. The dimensions of the egg-shaped dissected mass were 3.5 X 4 X 2.5 cm. A histological diagnosis of the wall of the mass showed that it was a pseudoaneurysm. Case 2: A 48-year-old female had been undergoing hemodialysis treatment since September, 1983. The left basilic vein, connected to the brachial artery, has been used for blood access. In April, 1984, a subcutaneous mass had developed at the blood access puncture point and an operation was performed within a few days. Operative findings revealed that the mass was a capsulized infected hematoma with a smooth but extremely thin and easily ruptured surface, and the section of the basilic vein surrounded by the mass showed evidence of necrotic change due to compression. The brachial artery was resutured at the region where it was previously connected to the basilic vein without disturbance of arterial blood flow. In July, 1985, an operation was performed in which a new blood access was constructed in the left thigh by superficializing the femoral artery and connecting its side to the end of the saphenous vein.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneurysm↗
PubMed1986

[Aluminum associated bone disease in patients undergoing long-term hemodialysis].

The widespread clinical use of hemodialysis has prolonged the survival of a vast number of uremic patients, but it has also yielded some problems including renal osteodystrophy. Recently, it has become well known that the clinical use of active vitamin D metabolites is effective in many patients with renal osteodystrophy. However, there are many patients with bone diseases resistant to such treatment. Several lines of evidences implicate aluminum as one of the causal factors in the production of such diseases. We recently found 20 patients with bone diseases associated with the deposition of aluminum in front of active calcification in the bone. All of them were undergoing maintenance hemodialysis with softened water thrice weekly and taking aluminum containing antacids and 1 alpha-(OH)D3. The age of the patients ranged between 30 y.o. and 62 y.o. (46.5 +/- 9.0, mean +/- s.d.). All of them had severe bone pain and 8 of them had bone fractures. Bone X-ray, bone scintigraphy, serum Ca, P, ALP, serum aluminum and bone histology were examined. Based on the bone histology, they were classified into four types; inactive type (9), osteomalacia type (6), mild type (4) and mixed type (1). There were no significant differences among each group concerning serum values of Ca, P and aluminum. Serum value of ALP tended to be high in the osteomalacia type, and that of c-PTH was significantly low in the inactive type compared with the other types. Our finding suggest that aluminum associated bone disease is not so rare in Japan and show that the diagnosis of this disease should be made histologically and that clinical and blood chemical features are not reliable for the diagnosis of aluminum associated bone disease in hemodialysis patients.

Adult↗