Biomedical subjects

H Miki

Publications and source records attributed to H Miki.

At least 253 records · Page 14Linked to original sources

PubMed1990

[Effects of novel immunosuppressant FK 506 in acute experimental allergic encephalomyelitis].

Experimental allergic encephalomyelitis (EAE) is a T cell-mediated autoimmune disease. It is widely used as an animal model of multiple sclerosis (MS). We studied the prophylactic effects of FK 506 electrophysiologically and immunohistochemically in acute EAE. Female Lewis rats were sensitized with guinea pig spinal cord in complete Freund's adjuvant. FK 506 suspended in distilled water was orally administered at 1.0, 3.2, 5.0 or 10.0 mg/kg per day for 12 successive days starting from the day of sensitization. A placebo was used as the control. Administration of FK 506 at doses of 3.2 mg/kg per day and over significantly delayed the onset of clinical signs. However, the FK 506 group showed a relapse or a chronic state following the onset of EAE. We made a time course recording of cortical somatosensory evoked potential (cortical SEP: P 15). P 15 latency in the placebo group was significantly delayed in accordance with the clinical signs and showed immediate improvement upon recovery. Prolongation of P 15 latency in the FK 506 group also occurred concomitantly with the clinical signs, but the delay continued after the loss of symptoms as well. After the onset of EAE, the infiltrating lymphocyte subset was examined by the avidin-biotin peroxidase complex (ABC) method in the lumbar spinal cord. In the placebo group, the number of OX3+ (Ia) cells and the W 3 25+: OX8+ (helper/inducer T: suppressor/cytotoxic T) ratio clearly reflected the development and remission of EAE. In the FK 506 group, however, increases in OX8+ lymphocytes were observed irrespective of clinical sign fluctuation, and there were corresponding decreases in the W 3/25+: OX8+ ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1990

[Eaton-Lambert syndrome manifested by respiratory failure associated with small cell carcinoma of the lung].

A 63-year-old man with Eaton-Lambert syndrome manifested by marked respiratory failure was reported. He began to notice blepharoptosis and diplopia in September, 1987, followed by weakness and easy fatigability in bulbar, neck and limb muscles in association with impotence by February, 1988. On admission in August, 1988, Gowers' sign, decreased tendon reflexes and muscle weakness improved by the injection of edrophonium were found. Anti-acetylcholine receptor antibody was negative. Single muscle action potential evoked in the thenar muscle was abnormally low in amplitude with the stimulation of the median nerve: repetitive nerve stimulation study revealed the waning at the low rates, but the waxing at the high rate (30 Hz), suggesting the diagnosis of Eaton-Lambert syndrome. Early gastric cancer (adenocarcinoma) was diagnosed from needle biopsy specimens in August, 1988, but no other neoplasm including thymoma or lung cancer was found. After subtotal gastric resection in September, 1988, he failed into respiratory failure, requiring artificial ventilation for seven months. Plasmapheresis and drugs such as anticholinesterase, guanidine hydrochloride, and corticosteroid were ineffective for the recovery from weakness in respiratory muscle. Lung cancer was suspected, based on a chest X-ray in March, 1989, and one month later he died of pneumonia. At autopsy, small cell carcinoma of the lung was observed, but there was neither recurrence nor metastasis of the gastric cancer. Emphasis was placed on the respiratory failure in Eaton-Lambert syndrome which has rarely been reported.

Adenocarcinoma↗

PubMed1990

[Subacute sensory neuropathy associated with carcinoma--an autopsy case report and an analysis of Japanese cases].

A 68-year-old man was admitted to our hospital because of numbness in the hands and feet, and unsteady gait in August, 1986. On neurological examination, deep tendon reflexes were absent in all limbs without pathological reflexes. Superficial and deep sensory disturbances of a glove and stocking type up to the level of the elbow and the knee were observed. Pseudoathetosis was noted in the hands. His gait was ataxic and Romberg sign was positive. Muscle strength was slightly decreased. Sural nerve biopsy showed severe loss of large myelinated fibers. Laboratory studies for malignancy showed lung cancer (Squamous cell carcinoma). Left pneumonectomy was performed in November, 1986, but he died in March, 1987. At autopsy, neither metastasis nor direct infiltration of malignant cells in the central and peripheral nervous systems were present macroscopically and histopathologically. Degeneration of the dorsal root ganglion and the posterior columns of the spinal cord were remarkable. Since 1955, only 9 cases of subacute sensory neuropathy had been reported in Japan. We analysed 10 Japanese cases (including our case) to clarify the clinicopathological features of subacute sensory neuropathy. Clinically, ataxic gait, paresthesia, deep sensory disturbance, and depression of deep tendon reflexes were present in the majority of the cases. Neuropathologically, neuronal cell loss and degeneration of the dorsal root ganglion, posterior roots and posterior columns of the spinal cord were universal findings.

Acute Disease↗

PubMed1990

[An epithelial myoepithelial carcinoma of the parotid gland].

A case of epithelial myoepithelial carcinoma is reported. Histologically, this tumor shows tubular and solid growth pattern. The inner layer of the tubules is composed of cells with an eosinophilic cytoplasm that is surrounded by cells with clear cytoplasms. Clear cells also manifest a solid growth pattern. Immunohistochemical and electron microscopic examinations has revealed that the cells with an eosinophilic cytoplasm have the characteristics of the ductal epithelium and that the clear cells have the characteristics of the myoepithelium. Immunohistochemically, keratin positive clear cells and S-100 protein positive ductal cells were found in our case. This suggests the existence of cells having both ductal and myoepithelial characteristics and this inspected tumor had derived from multipotential cells of intercalated ducts.

Actin Cytoskeleton↗

PubMed1990

[Acute transverse myelitis associated with ECHO-25 virus infection].

A case of acute transverse myelitis associated with ECHO-25 virus infection was reported here with a brief review of the literature. The patient was a 42-year-old house wife. Without any antecedent symptoms, weakness and paresthesia of bilateral lower extremities, and sphincter disturbance developed suddenly. Neurological examination revealed paraplegia of both legs, hyperreflexia of lower extremities, bilateral positive Babinski sign and impairment of all sensory modalities below Th4 level. No abnormality was found in myelography and CT myelography. Abnormal intensity area was found in lower cervical spinal cord on MRI. Serum antibody titer to ECHO-25 virus was elevated in the convalescent stage (X4096), and 7 month later from the onset of neurological symptoms, high value was continued (X128). We diagnosed her illness as acute transverse myelitis complicating ECHO-25 virus infection. In the literature, only 3 cases of transverse myelitis following ECHO virus infection (type 2, 5, 19) were found. This case seemed to be the first case of transverse myelitis associated with ECHO-25 virus infection.

Acute Disease↗

PubMed1990

[A case of posterior cerebral artery territory infarction with micropsia as the chief complaint].

A 63-year-old man was admitted to the hospital complaining that all objects in his vision suddenly appeared small. Examination on admission revealed amnesia of recent events, recognition memory deficits, emotional disturbance, right upper quadrantanopsia and micropsia. The patient was diagnosed as posterior cerebral artery territory infarction based on brain CT scan and MRI findings which showed an ischemic lesion involving the left occipital lobe and hippocampus. We regarded the quadrantanopsia to have originated in the occipital lobe lesion and memory and emotional disturbances to have originated in the hippocampal lesion. After admission, micropsia and disturbances of memory and emotion improved within a month, but the quadrantanopsia did not recover. A comparison of the 25th and 2nd day brain CT scans indicated that the low density of the ischemic lesion near the hippocampus had become less clear and smaller. These findings suggest that the pathogenesis of micropsia in this case was a visual perceptional abnormality due to edematous change in the structures near the hippocampus. Cases of occipital artery territory infarction with micropsia, disturbances of memory and emotion, and quadrantanopsia appear to be rare, but micropsia may be overlooked since it is often masked by disturbance of memory or emotion.

Cerebral Arteries↗

PubMed1990

[Surgical treatment of aortic arch aneurysm associated with the aberrant right subclavian artery].

A 64-year-old man, who had an aneurysm of aortic arch associated with the aberrant right subclavian artery, was treated successfully. He was pointed out to have an aneurysm of aortic arch three years ago. Three years later angiograms and computed tomography revealed that it became larger compared with the initial finding. He underwent a replacement of the aortic arch using a woven Dacron graft under open distal method. Aberrant subclavian artery was not involved in the aneurysm. But because the left subclavian artery was involved in it, a woven Dacron graft was interposed between the ascending aorta and left subclavian artery. Postoperative course was uneventful and there were no complications.

Aorta, Thoracic↗

PubMed1990

[Significance of inferior ST segment changes in acute anterior myocardial infarction--relationship between the distribution of left anterior descending artery and concomitant ischemia of the inferior wall].

The significance of inferior ST segment changes was studied in 23 patients with acute anterior myocardial infarction by the distribution of the left anterior descending artery (LAD) after percutaneous transluminal coronary recanalization. In 9 patients (Group A) LAD supplied the anterior wall of the left ventricle up to or including the apex but did not reach the inferior wall; in 8 patients (Group B) it continued beyond the apex onto the inferior wall of the left ventricle with well developed collateral circulation; in 6 patients (Group C) it continued beyond the apex onto the inferior wall of the left ventricle with less-developed or no collateral circulation. Thallium-201 scintigraphy and contrast left ventriculography showed that inferior myocardial ischemia was significantly more prominent in Group C than Group A. These results were consistent with coronary anatomy. Inferior ST segment was significantly more depressed in Group A with no concomitant inferior wall ischemia, than in Group C with concomitant inferior wall ischemia (maximal inferior ST segment change: -1.7 +/- 1.1; 0.8 +/- 1.7 mm, respectively; p less than 0.02). In Group A inferior ST segment was depressed in all 6 patients with lateral ST segment elevation, but it was depressed in only one of 3 patients with no lateral ST segment change. Lateral ST segment elevation tended to cause inferior ST segment depression. This study indicates that the inferior ST segment changes in patients with acute anterior myocardial infarction depend on concomitant ischemia of the inferior wall of the left ventricle by the distribution of LAD and the lateral ST segment changes.

Adult↗

PubMed1989

Electron spin resonance spectrum of Tyr-151 free radical formed in reactions of sperm whale metmyoglobin with ethyl hydroperoxide and potassium irridate.

A five-line ESR spectrum was observed at room temperature in reactions of sperm whale metmyoglobin with ethyl hydroperoxide (EtOOH) at pH 9.5 and with potassium irridate at pH's 7.0 and 9.5. A spectrum with the same g value and hyperfine splitting constant appeared in a reaction of sperm whale apomyoglobin with potassium irridate and was assigned to a tyrosyl radical on the basis of optical spectrum data obtained under the same reaction conditions. It was concluded that this radical arose from Tyr-151 for the following reasons. (i) This ESR spectrum could not be observed in the reaction of horse heart metmyoglobin, which lacks Tyr-151. (ii) Sperm whale metmyoglobin no longer gave this spectrum when treated with tetranitromethane (TNM) under conditions in which approximately one tyrosine is lost in sperm whale metmyoglobin but none is lost in horse heart metmyoglobin. (iii) A complex ESR spectrum observed in the reaction of sperm whale metmyoglobin with EtOOH at neutral pH was found to be a mixture of this five-line spectrum and one arising from an unidentified free radical formed in the reaction of horse heart metmyoglobin with EtOOH. The TNM-treated sperm whale metmyoglobin gave the same ESR spectrum as that observed in the reaction of horse heart metmyoglobin with EtOOH.

Animals↗

PubMed1989

Effect of coenzyme Q10 on hemodynamic response to ocular timolol.

Coenzyme Q10 (CoQ10) is an essential component of the mitochondrial membrane and plays an important role in the maintenance of normal cardiac function. To evaluate the effects of ocular timolol on the cardiovascular system and determine the protective effect of CoQ10, 16 patients with glaucoma were studied using impedance cardiography. Following instillation of 1 mg timolol maleate in each eye, heart rate (HR) and stroke index (SI) decreased, and total peripheral resistance index (TPRI) increased significantly. Reexamination was performed after 6 weeks of 90 mg oral CoQ10. Despite decreases in HR, percent changes in HR were significantly less after CoQ10 at 120 min. Stroke index showed an initial increase which was not observed without CoQ10. These data suggest that CoQ10 delayed the appearance of inotropic blockade of timolol and hastened the disappearance of chronotropic blockade. Additional study of six normal volunteers with 6 weeks of oral CoQ10 showed a similar decrease of intraocular pressure after timolol instillation as compared to those without CoQ10. Thus, administration of oral CoQ10 in patients receiving ocular timolol may be useful in mitigating cardiovascular side effects without affecting intraocular pressure in the treatment of glaucoma.

Administration, Oral↗

PubMed1989

Step response of lung surface-to-volume ratio by light-scattering stereology.

By means of backscattered light from a pointlike source on the pleural surface, we investigated the dynamic behavior of the surface-to-volume ratio (S/V) in excised dog lobes subjected to small volume steps both in and out on both the inflation and deflation limb of standard pressure-volume maneuvers. The technique utilizes the established correlation of the pattern of backscattered light with morphometric mean linear intercept and is suitable for dynamic studies. We hypothesized that 1) there would be a difference in the timing of stress relaxation or recovery between alveolar septa and the fibromuscular tissue in the alveolar duct that would reveal itself as a temporally changing S/V after a step-volume change and 2) that geometric hysteresis (looping of S/V with volume), as seen with large volume excursion histories, would be similarly present in small tidal volume loops. Our experimental results contradicted both hypotheses. In particular, we found virtually no change in S/V after a step-volume change, even in the presence of substantial stress adaptation. In addition, when geometric hysteresis of small loops was present, it was always in the sense opposite to the geometric hysteresis of large loops. We conclude that 1) there is a functional "matching" of the stress-adaptive timing between alveolar septa and ductal mouths and 2) during small volume looping, the stress hysteresis (looping of stress with volume) in the ductal tissue may be larger than that of the septa, including surface tension.

Animals↗

PubMed1989

Effects of electrical stimulation of the genioglossus on upper airway resistance in anesthetized dogs.

We examined the relationship between the frequency of stimulation of the genioglossus and upper airway resistance in six anesthetized dogs in the supine position. The upper airway was isolated from the lower airway by transecting the cervical trachea, and the pressure flow relationship of the upper airway was obtained by applying constant negative pressure (5, 10, and 20 cm H2O) to the proximal cut end of the trachea. Electrical stimulation of the genioglossus was performed at a constant voltage (10 to 20 V) and at various frequencies (as high as 100 Hz). Upper airway resistance (Rua) during both inspiration and expiration increased with an increase in tracheal negative pressure, and at each tracheal negative pressure Rua was significantly reduced by stimulation of the genioglossus. The effects of genioglossal muscle stimulation were nonlinearly dependent on the stimulating frequency. Below 50 Hz, Rua decreased markedly as the stimulating frequency was increased, but above 50 Hz, Rua plateaued at a minimum value. These findings suggest that at a stimulating frequency of more than 50 Hz, upper airway patency is stably maintained in anesthetized dogs.

Airway Resistance↗

PubMed1989

Effects of submental electrical stimulation during sleep on upper airway patency in patients with obstructive sleep apnea.

We examined the effects of percutaneous electrical stimulation of the genioglossus in six patients with obstructive sleep apnea syndrome (OSAS) during sleep and investigated the possible applicability of this procedure as a treatment of OSAS. Six patients with OSAS were polysomnographically studied in the supine position during all-night sessions with and without electrical stimulation of the genioglossus. Using an apnea demand-type stimulator that we developed, electrical pulses of 0.5 ms (repetition rate, 50 Hz) and 15 to 40 V were delivered through bipolar electrodes (10 mm in diameter) attached to the skin of the submental region when apnea lasted more than 5 s, and was stopped immediately after breathing resumed or after 10 s at the longest. With submental stimulation, the apnea index, apnea time/total sleep time, longest apnea duration, and the number of times per hour that oxygen saturation dropped below 85% decreased significantly compared with those on control nights. The lowest arterial oxygen saturation and the duration of sleep stages III and IV increased significantly. The stimulation employed did not cause arousal, and it did not affect blood pressure or heart rate significantly. These findings show that submental stimulation decreases the incidence of apnea episodes and promotes deeper sleep without accompanying serious side effects, suggesting that the apnea demand-type stimulator may be a noninvasive and effective treatment for OSAS.

Electric Stimulation↗

PubMed1989

[Morphological study of experimental corneal neovascularization after anterior uveal ischemia].

We morphologically investigated what kinds of inflammatory cells infiltrate the corneoscleral limbus by light and electron microscopy and what manner of keratocytes and vascular endothelial cells appear at the corneal limbus, when the corneal edema was aggravated severely and clinical corneal new vessels were found initially, i.e. until three days after anterior segmental ischemia in rabbit eyes. The majority of infiltrating inflammatory cells were polymorphonuclear leukocytes and the others were lymphocytes and histiocytes etc. Peripheral keratocytes around limbal vessels were stimulated and transformed to fibroblastic cells as a result of anterior segment ischemia. Proliferating endothelial cells of comparatively minor limbal vessels invaded between corneal lamellar layers toward the corneal center. Polymorphonuclear leukocytes were often found near activated keratocytes proliferating vascular endothelial cells, hear and there. Consequently, it is considered that the stimulated polymorphonuclear leukocytes play an important role when corneal neovascularization occurs after anterior segmental ischemia.

Animals↗

PubMed1989

[Isolation perfusion chemotherapy using cisplatin in malignant tumors of the extremities].

Since 1960 isolation perfusion chemotherapy has been performed as a preoperative procedure combined with surgery in 226 patients with malignant tumor of the extremities in our department. In this report we presented the result of isolation perfusion chemotherapy using cisplatin (CDDP) for 27 patients since 1983. The histologic classification of the malignant tumor was osteosarcoma in 17 patients, malignant fibrous histiocytoma (MFH) of bone in 8, and other tumor in 2. The extremity was perfused with CDDP (100 micrograms/ml) for 60 minutes. Of 27 patients, 11 were treated with hyperthermic isolation perfusion. The two-year survival rate of the 15 patients with osteosarcoma was 80%, and that of the 7 patients with MFH of bone 71%. The tumor was microscopically analyzed, and the ratio of necrotic to viable tumor cells was calculated. The degree of tumor necrosis was classified as excellent (greater than or equal to 95%), good (80-94%), fair (50-79%), and poor (less than 50%). Of 16 patients, 7 were excellent, 5 good, 3 fair and 1 poor. We concluded that isolation perfusion chemotherapy using CDDP is an effective procedure combined with surgery for malignant tumor of the extremities.

Adolescent↗

PubMed1989

[A case of mediastinal immature teratoma with elevated levels of CA19-9].

A 15-year-old woman was found to have a large anterior mediastinal mass on chest roentgenogram. Preoperatively, serum levels of CA19-9 were found to be elevated. From the result of pathological study on the resected lesion, it was diagnosed as immature teratoma. The fluid levels of CA19-9 extracted from the tumor were found to be elevated. Part of the tumor, the pancreas, the bronchial epithelium and the intestinal epithelium, were shown positive staining in immunoperoxidase assay using anti CA19-9 antibody. The postoperative course was satisfactory and the serum levels of CA19-9 returned to normal. In mediastinal germ cells tumors, there are no cases reported in which CA19-9 was detected in serum and in the tumors. In order to define the relation between mediastinal germ cell tumors and CA19-9, further more cases should be investigated.

Adolescent↗

PubMed1989

[Morphological study of corneal edema after anterior segment ischemia].

This experiment was performed to investigate the correlation between morphological changes of the corneal endothelium and clinical corneal edematous opacities after a procedure causing obstruction of bilateral long posterior ciliary arteries of the albino-rabbits. Shortly after the procedure, corneal endothelium became irregular on the anterior-chamber side and there were numerous lysosomal granules in the cytoplasm of corneal endothelial cells. On the third day, endothelial cells became necrotic and collapsed and a part of the cells peeled into the anterior chamber. Fibroblast-like cells and inflammatory cells were piled up in severely damaged areas of the endothelium. On the 11th day, the corneal endothelium developed again as a single layered structure on Descemet's membrane. It's seemed that corneal edema was induced as a result of severe damage corneal endothelium exposed to biochemical mediators such as prostaglandins released into the aqueous humor because the severity of corneal edema indicated some relation to changes in the concentration of prostaglandins in aqueous humor after anterior segmental ischemia.

Animals↗

PubMed1989

[An autopsied case of idiopathic interstitial pneumonia, showing a remarkably elevated serum level of CA 19-9].

Discussed herein is an autopsied case of a 30-year-old male with Idiopathic Interstitial Pneumonia (IIP) manifesting a markedly elevated CA 19-9 in the serum (maximum, over 120,000 U/ml). Despite a careful examination, no malignant lesion was found. The postmortem examination revealed a marked elevation of CA 19-9 in the serum and in the lung tissue. Further immunohistochemically regenerative bronchiolar and alveolar epithelial cells were more intensely positive for CA 19-9 than in our controls. These CA 19-9 positive cells for the most part, were found to stain with alcian blue. It is considered that IIP induces activation of sialyl-transferase in these cells.

Adult↗