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Biomedical subjects

H Aoki

Publications and source records attributed to H Aoki.

At least 343 records · Page 19Linked to original sources
PubMed1991

[A case of right atrial myxoma--the availability of transesophageal echocardiography in the detection of right atrial myxoma].

A 72-year-old woman had experienced palpitation and fatigue during exertion for two months and was referred to our hospital from her nearby hospital. On physical examination, a systolic murmur was heard in the left fourth intercostal space. A chest X-ray film showed cardiac enlargement (CTR 64%). An ECG showed elevated P waves in leads II, III. Transthoracic echocardiography revealed a large oval heterogeneous mass in the right atrium. Transesophageal echocardiography (TEE) revealed the right atrial mass clearly, which was attached to the atrial septum with a short wide stalk. This mass prolapsed from the right atrium into the right ventricle in diastole. And there were some cysts in the homogeneous high-echoic lesion. The chest CT and MRI also showed the mass in the right atrium. However, these images were not clear. Surgical excision of the mass was undertaken. A solid mass measuring 75 x 50 x 45 mm was attached to the fossa ovalis with a wide short stalk. There were several cysts in the mass. Pathological examination showed myxomatous tissue. In this case, TEE was the most valuable means for evaluation of the right atrial mass.

Aged↗
PubMed1991

[Clinicopathological study of midbrain corectopia].

A clinicopathological study was conducted in 19 cases (including 9 autopsied) of midbrain corectopia (oval pupil) occurring in the acute stage of cerebrovascular disorders. This ocular symptom manifested itself in conjunction with severe impairment of consciousness invariably in all instances, unilaterally in 11 and bilaterally in 8 cases, with the shape of the pupil and the direction of its displacement varying from case to case. In 17 cases, this patients died several hours to several days after the appearance of this sign. On autopsy were noted small hemorrhagic lesion of the upper mesencephalic tegmentum in 2 cases and conspicuous cerebral herniation in 7 cases. In this study, it was thought that all cases had diffuse lesions including nuclear, infra- and/or supra-nuclear parts of the midbrain. Clinicopathologically, it was difficult to define the corresponding lesion for corectopia. We suggested that this ocular symptom which appeared transiently was the sign of poor prognosis.

Adult↗
PubMed1990

Biological and immunological properties of human hepatocyte growth factor from plasma of patients with fulminant hepatic failure.

We have recently purified human hepatocyte growth factor (hHGF), a heterodimer with molecular weight of about 83,000, from plasma of patients with fulminant hepatic failure (Gohda, E. et al., J. Clin. Invest. 81, 414-419, 1988). Biological and immunological properties of hHGF were examined. Out of the well-known growth factors tested, only epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) stimulated DNA synthesis of adult rat hepatocytes in primary culture. hHGF enhanced the DNA synthesis at less than one-tenth of the molar concentrations of EGF and TGF-alpha. Half-maximal stimulations by hHGF, EGF and TGF-alpha were observed at 30, 400 and 900 pM, respectively. Maximal stimulation by TGF-alpha, however, was greater than those caused by hHGF and EGF. The effect of hHGF was additive with the maximal effects of EGF and TGF-alpha. Anti-hHGF antiserum was prepared in a rabbit by injecting with purified hHGF. This antiserum recognized nonreduced hHGF, but not reduced hHGF. The antiserum for hHGF did not inhibit growth-promoting activity of EGF, that was neutralized by incubation with anti-EGF antiserum. The activity of hHGF was completely inhibited by anti-hHGF antiserum, but not by anti-EGF antiserum. hHGF did not show any cross-reactivity to anti-EGF antiserum as measured by enzyme immunoassay for EGF. Thus, biological and immunological properties of hHGF are different from those of EGF and TGF-alpha.

Animals↗
PubMed1990

Development of the rat meninx: experimental study using bromodeoxyuridine.

The development of the rat meninx from the viewpoint of cell proliferation was studied microscopically and immunohistochemically using bromodeoxyuridine (BUdR). A compact cell layer around the neural tube, the meninx primitiva, was observed in 12- and 13-day fetuses. A reticular structure resembling the subarachnoid space appeared in the 14-day fetus. The ectomeninx, consisting of a collagen fiber layer, part of which became the dura mater, appeared in 15-day fetuses, allowing discrimination of the endomeninx, the arachnoid cell layer. The primordium of the choroid plexus also appeared in the lateral ventricle on the same day. Bone appeared in the primitive dura mater, and stratification of the meninx was almost complete in 21-day fetuses. BUdR-positive cells were confirmed in the meninx from day 12 of gestation to day 15 postpartum. The number of BUdR-positive cells was greatest in fetuses aged about 12 or 13 days, reaching nearly 50%, but decreased gradually toward the neonatal period. The findings of this study suggest that, after the migration of neural crest cells, marked cell proliferation in the meninx begins. Differentiation into various layers then follows and is almost complete before birth, whereas the proliferation of arachnoid cells continues even in the early neonatal period.

Animals↗
PubMed1990

Transferrin receptors in injured brain.

Recent studies have demonstrated the presence of transferrin receptors (Tf-R) in the central nervous system. The present study of Wistar rats with experimentally induced brain injuries, using immunohistochemistry at the light microscopy level, demonstrated the presence of Tf-R in regenerated endothelial cells, reactive astrocytes and in other cells, probably macrophages. Although Tf-R were seen in proliferating cells, Tf-R were also observed in non-proliferating cells, many of them macrophages. The receptors perhaps bind transferrin in edema fluid and play an important role in lesion repair.

Animals↗
PubMed1990

Cloning of a Bacteroides gingivalis outer membrane protein gene in Escherichia coli.

Gene banks of chromosomal DNA from Bacteroides gingivalis 381 were constructed using the bacteriophage replacement vector lambda L47.1. A clone encoding an outer membrane protein from B. gingivalis was identified by Western blot screening with antiserum raised against the outer membrane fraction of B. gingivalis 381 cells. The DNA insert contained within this phage was cloned into the plasmid vector pACYC184 to create the recombinant plasmid pMD123. An Escherichia coli transformant, MD123, containing pMD123 produced a protein having an apparent molecular weight of 40 kDa. The recombinant protein was purified, and amino acid analysis revealed the recombinant protein to have a relatively high content of hydrophobic amino acids (43.6%). Antiserum against the purified recombinant 40 kDa protein reacted with a polypeptide of similar size in the outer membrane fraction and vesicles of B. gingivalis.

Amino Acids↗
PubMed1990

Cerebral sparganosis mansoni. Report of two cases.

Among diseases due to cerebral parasitism, that caused by Sparganum mansoni, the larva of Spirometra mansoni, is very rare. We have encountered two such cases. A computed tomography scan in both revealed a nodular high density contrast enhanced area against an extensive low density background area. Neither calcification nor cyst formation was recognized. These computed tomography scan findings were thought to be characteristic for cerebral sparganosis mansoni and were difficult to differentiate from those of a cerebral tumor. In both cases, definitive diagnosis was achieved by identification of the worm after excision of the lesion. The best treatment for cerebral sparganosis mansoni is surgical excision of the lesion, and in the two cases presented the postoperative outcome was good.

Animals↗
PubMed1990

Combined effects of intraperitoneal administration of recombinant interleukin-2 and streptococcal preparation OK-432 in murine tumors.

The combined effects of rIL-2 and OK-432 were investigated against a Meth-A tumor, a syngeneic tumor of inbred BALB/c mice. An analysis of the effector cells was also performed. The treatment resulted in an inhibition in vivo of tumor growth and increased survival of the Meth-A tumor-bearing mice. Splenic cells obtained from Meth-A inoculated mice which received combination therapy were not only NK-sensitive YAC-1 and LAK-sensitive EL-4 cells, but also NK-resistant Meth-A cells, as shown in a 4-h 51Cr-release assay. Syngeneic killer cell activity against Meth-A cells was abolished almost completely with anti-Thy 1.2 treatment and about 70% of the activity was abolished with anti-asialo GM1 treatment in a complement-dependent cytotoxic assay. It was not changed by the removal of macrophages and B cells from the splenic cells. Mice which survived for 60 days after the start of therapy rejected Meth-A inoculation when rechallenged, suggesting the establishment of a specific immunity. Combination therapy appeared to be beneficial against Meth-A cells and T-cells appeared to play a determining role in the treated Meth-A bearing mice. It was suggested that more than two populations of killer cells exist in the spleen treated with the combined therapy and they may have the same characteristics as activated T and NK cells with or without specific killer T-cells.

Animals↗
PubMed1990

Post-ischemic synaptic plasticity in the rat hippocampus after long-term survival: histochemical and autoradiographic study.

The hippocampus provides a suitable area in the brain for the analysis of neuronal plasticity after application of a selective lesioning technique. Using histochemistry and autoradiography, we studied synaptic reorganization in the rat hippocampus with selective CA1 pyramidal cell lesioning caused by transient forebrain ischemia after long-term survival. An autoradiographic study was performed on second messenger systems ([3H]inositol 1,4,5-trisphosphate, [3H]forskolin and [3H]phorbol 12,13-dibutyrate binding). One-hundred days after ischemia, depletion of CA1 pyramidal cells and marked shrinkage of the CA1 subfield was noted in spite of unaltered thickness of the CA3 band and of the dentate molecular layers. Although neuronal density in the CA3 region of animals killed seven days after ischemia was not different from the normal group, 78% of animals showed neuronal loss of 30-50% in the stratum pyramidale of the CA3b 100 days after recirculation. Sixty-seven per cent of animals exhibited supragranular mossy fiber sprouting in the dentate gyrus. However, CA3 neuronal loss did not correlate with mossy fiber sprouting. Succinic dehydrogenase was depleted in the CA1 100 days after ischemia, and animals with CA3 damage showed a reduction of succinic dehydrogenase activity in the CA3. In contrast to the unaltered acetylcholinesterase in the animals killed seven days after ischemia, high density bands of acetylcholinesterase activity in the stratum pyramidale of the CA1 were found to be broadened 100 days after ischemia. In the CA1 subfield, subnormal activity of [3H]phorbol 12,13-dibutyrate and [3H]forskolin binding were observed in spite of the depleted [3H]inositol 1,4,5-triphosphate binding. [3H]Forskolin binding in the hilus had increased by 62% 100 days after ischemia, although binding in the stratum lucidum of the CA3 and in the stratum moleculare of the dentate gyrus was unaltered. However, no visible supragranular increase in [3H]forskolin binding was observed. These results indicate that long-term survival after CA1 pyramidal cell depletion caused by transient forebrain ischemia induced the modulation of neuronal activity and synaptic rearrangements in the whole hippocampal formation.

Acetylcholinesterase↗
PubMed1990

Effect of chemical modifications of tryptophan residues on the folding of reduced hen egg-white lysozyme.

The effects of chemical modifications of Trp62 and Trp108 on the folding of hen egg-white lysozyme from the reduced form were investigated by means of the sulfhydryl-disulfide interchange reaction at pH 8 and 40 degrees C. The folding of reduced lysozyme was monitored by following the recovery of the original activity. Under the conditions employed, the apparent first-order rate constant for the folding of reduced lysozyme was not changed by the modifications of both Trp62 and Trp108 and the folding was completed within 30 min. However, the extent of the correct folding was changed by the modification of Trp62 but not by that of Trp108. Native and oxindolealanine108 lysozymes recovered 80 and 81% of their original activities after 30-min refolding, respectively, but Trp62-modified lysozymes recovered their activities to a lesser extent than native and oxindolealanine108 lysozymes. The recovered activities of Trp62-modified lysozymes after 30-min refolding were 63% for oxindolealanine62 lysozyme, 65% for delta 1-carboxamidomethylthiotryptophan62 lysozyme, and 52% for delta 1-carboxymethylthiotryptophan62 lysozyme. These results suggest that Trp62 is important for preventing the misfolding of reduced lysozyme, but that neither Trp62 nor Trp108 is involved in the rate-determining step (the slowest step) in the folding pathway. A decrease in the hydrophobic nature of Trp62 seems to increase the misfolding and thus to decrease the extent of the correct folding of reduced lysozyme. A mechanism for the involvement of Trp62 in the folding pathway of reduced lysozyme is proposed.

Amino Acid Sequence↗
PubMed1990

Nucleolar organizer regions in meningioma.

Seventy-eight cases of meningioma and related tumors were examined independently using a simple and reproducible argyrophilic method for the demonstration of nucleolar organizer regions (AgNORs) and staining with bromodeoxyuridine monoclonal antibody. The mean number of AgNORs per cell and the bromodeoxyuridine labeling index were shown to be linearly related (r = 0.84, P less than 0.001). The mean AgNOR number was 2.99 for meningeal sarcoma, 2.29 for anaplastic meningioma, 2.08 for hemangiopericytic meningioma. 1.72 for recurrent meningioma without atypical histological findings, and 1.52 for nonrecurrent meningioma. We noted that the mean number of AgNORs reflected the cellular kinetics of a tumor and was related to histological grade and clinical behavior.

Bromodeoxyuridine↗
PubMed1990

Clinical studies on the effectiveness of prazosin HCl (Minipress tablets) in the treatment of dysuria accompanying benign prostatic hyperplasia.

Prazosin HCl was administered in dosages of 1.5-4.5 mg/day for 4 weeks to 40 patients suffering from dysuria accompanying prostatic hyperplasia. Significant reductions were observed in the mean frequency of night-time and 24-hour urination. Additionally, significant improvements were recorded for the time for start of urination, time from start to finish of urination and related variables. The improvements correlated with dosage levels. Objective variables measured by urine flow rates also exhibited significant improvement. A statistically significant decrease in systolic without a decline in diastolic blood pressure was observed. Slight dizziness was observed in 1 patient and elevated laboratory test values in another, but neither warranted discontinuation of the medication; however, 1 patient did have two doses of medication held. Overall, the drug was judged beneficial to some degree in 95% of the patients.

Aged↗
PubMed1990

Clinical evaluation of effects of prazosin in patients with benign prostatic obstruction. A double-blind, multi-institutional, Paraprost-controlled study.

Prazosin, a selective alpha 1-adrenoceptor blocker, was compared with Paraprost in a double-blind, multi-institutional study in patients with benign prostatic hyperplasia. The trial encompassed 77 evaluable patients in the prazosin group and 79 in the Paraprost group. Both drugs significantly improved obstructive and irritative symptoms. Residual urine (volume or percentage of total urine) was reduced by both prazosin and Paraprost. Average and maximum flow rates increased significantly in the prazosin group while those were unchanged in the Paraprost group. Side effects occurred in 1 patient treated with prazosin (1.1%) and 3 patients with Paraprost (3.3%). Thus, we confirm the clinical value and minimal side effects of prazosin in the treatment of bladder outflow obstruction resulting from benign prostatic hyperplasia.

Aged↗
PubMed1990

Ca2(+)-insensitive contraction in glycerinated skeletal muscle fiber treated with additional troponin T.

An investigation was carried out on the effect of troponin T (TnT) protein on the Ca2(+)-sensitivity of fiber contraction when it was added to glycerinated muscle fiber. The TnT-treated fiber was observed to lose its Ca2(+)-sensitivity, so that it was seen to contract even in a Ca2(+)-free buffer solution. However, the treated fibers were not significantly different from the normally glycerinated ones in terms of tension magnitude. On the other hand, the fiber did not lose its Ca2(+)-sensitivity upon treatment in a similar manner with troponin I (TnI) or troponin C (TnC) protein instead of TnT; the tension magnitude was seen to decrease only with the TnI treatment. SDS-PAGE patterns of the TnT-treated fibers were different from those of glycerinated ones at the TnI and TnC band, which were fainter in the TnT-treated fibers than in the normal ones. DACM-labeled fibers also decreased in the DACM-labeled TnI and TnC proteins on gel as a result of the treatment with TnT protein. Further, those proteins were completely removed from fibers into extra medium. These findings suggest either that the additional TnT protein removes TnI and TnC subunits from the troponin (Tn) complex combined with thin filaments in the fibers, or that it exchanges the total Tn complex on the thin filaments.

Animals↗