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Biomedical subjects

K Miyoshi

Publications and source records attributed to K Miyoshi.

At least 91 records · Page 5Linked to original sources
PubMed1997

[Choroidal lesions and surgical treatment of bullous retinal detachment].

To define choroidal lesions of bullous retinal detachment, we performed indocyanine green angiography (IA) on 20 eyes of 10 patients with bullous retinal detachment. Four of these eyes were treated with sclerectomy and sclerostomy (Gass), and the benefit was evaluated. IA showed the following choroidal abnormalities: choroidal filling delay in the macular region (6 of 18 eyes, 33%) and underneath the leaking sites (9 of 18 eyes, 50%), localized (1 eye, 5%) and extended (18 eyes, 90%) choroidal venous dilatation, and intrachoroidal hyperfluorescence (all eyes, 100%). After the surgical treatment, retinal detachments resolved within 9 weeks (mean 5.3 weeks). Since choroidal filling delay, choroidal venous dilatation and intrachoroidal hyperfluorescence were observed, it is suggested that choroidal congestion plays a causative role in bullous retinal detachment. Sclerectomy and sclerostomy seemed to be beneficial in treatment of this condition.

Adult↗
PubMed1997

[Effects of oral amezinium metilsulfate in patients with sick sinus syndrome].

The effects of amezinium metilsulfate (Risumic) were studied in patients with sick sinus syndrome. Four males and 11 females with clinical symptoms were treated with 0.5 mg/kg for 1 to 40 weeks. In all patients, the length of sinus pause observed during 24-hour Holter monitoring was longer than 2.0 sec, and/or the sinus node recovery time in the electrophysiologic study was longer than 2.0 sec. The effects were evaluated by Holter monitoring and standard electrocardiography. The total number of heart beats every 24 hours by Holter monitoring were significantly increased from 78,917 +/- 15,983 (mean +/- SD) to 85,753 +/- 17,849 beats after the treatment. The length of the sinus pause was significantly decreased from 3.89 +/- 1.24 to 2.36 +/- 1.45 sec. Patients with sinus node recovery time of less than 5.0 sec showed the effects especially clearly. The total number of premature ventricular contractions was decreased from 530 +/- 767 to 123 +/- 182 beats. The PQ, QRS and QTc intervals did not change. Only diastolic pressure was slightly increased. Clinical symptoms disappeared in almost all patients and the clinical courses were favorable. Amezinium metilsulfate, which stimulates the intrinsic sympathetic nervous system, increased total heart beat and shortened sinus pause in patients with sick sinus syndrome. Few side effects, such as arrhythmogenecity or increase of blood pressure were observed. These results show that amezinium metilsulfate is useful in the treatment of patients with sick sinus syndrome, if the disease is not so severe as to require implantation of a cardiac pacemaker.

Administration, Oral↗
PubMed1997

Reduplicative paramnesia in patients with focal brain damage.

Reduplicative paramnesia (RP) has drawn attention as a distinct behavioral syndrome caused by focal brain damage. To elucidate the pathogenesis of RP, we assessed its prevalence among patients with focal brain damage and followed those patients with typical RP. Seventy-seven patients with focal brain damage (47 with left hemispheric, 21 with right hemispheric, and 9 with bilateral damage) were assessed for the presence of RP using a questionnaire intended to elucidate this condition. Two patients showed typical RP for place, and four patients showed atypical RP (three for place and one for person); altogether, these six patients constituted 7.8% of the sample. In three patients, the lesions were situated in the right hemisphere; in two, the lesions were bilateral (right dominant); and in one, the lesions were in the left hemisphere, indicating the relative importance of right hemispheric damage and a possible contributory role of additional left hemispheric damage in RP. The case studies of patients with typical RP suggest the heterogeneity of the underlying cognitive factors in RP.

Adolescent↗
PubMed1996

A report on the safety of unilateral vertebral artery ligation during cervical spine surgery.

STUDY DESIGN: This study retrospectively analyzed the outcome of unilateral vertebral artery ligation during cervical spine surgery. OBJECTIVES: To examine the influence of unilateral vertebral artery ligation on the function of brain and spinal cord. SUMMARY OF BACKGROUND DATA: There was little published information about the outcome of a vertebral artery ligation except for several reports from the field of neurosurgery. METHODS: Unilateral vertebral artery ligation was used in 15 patients with cervical tumors of the spine or the spinal cord (age range, 13-71 years; nine male patients and six female). The authors ligated the involved vertebral artery only when the tumor appeared on the minor or equal diameter artery side measured by pre-operative angiogram. The patient's condition was examined regarding signs of dysfunction of the brain stem, the cerebellum, or the spinal cord. RESULTS: Preoperative angiogram showed that the involved vertebral artery had a smaller diameter in four patients and had an equal diameter in 11 patients compared with the one not involved. The involved vertebral artery was severed at single site in four patients and was resected between two distant sites of ligation in 11 patients. Examination after surgery of the patient's condition (follow-up periods ranged from 10 months to 7 years) revealed that unilateral vertebral artery ligation did not provoke any symptoms of damage resulting from ischemia of the brain stem, the cerebellum, or the spinal cord. CONCLUSION: A vertebral artery could be ligated uneventfully when the diameter of the vertebral artery was not larger than the one not involved. Where vertebral artery ligation could not be avoided, it should be confirmed by preoperative angiogram that the other vertebral artery is large enough and that simultaneous occlusion testing of the involved vertebral artery is uneventful.

Adolescent↗
PubMed1996

Early morning urine osmolality in nonenuretic and enuretic children.

Early morning urine osmolality in 1,453 nonenuretic children and 144 enuretic children was measured in a population study. Early morning urine osmolality was lower in nonenuretic children aged 3-4 years than in those aged over 5 years. A similar pattern was observed in enuretic children. No significant difference in early morning urine osmolality was observed between nonenuretic children and enuretic children at any age. These data suggest that nocturnal urine concentration may be immature in nonenuretic children under 4 years. We did not find any evidence for increased nocturnal urine production as a cause of enuresis.

Aging↗
PubMed1996

Histological evidence for cholinergic alteration in the hippocampus following entorhinal cortex lesion.

The initial stage of Alzheimer's disease is characterized by neuropathological alteration in the entorhinal cortex. To model one aspect of the neurodegeneration observed and to investigate anatomical changes of the hippocampus associated with unilateral entorhinal cortex lesion, excitotoxin ibotenic acid was used to produce selective unilateral neuronal loss in rat entorhinal cortex. Histological and morphometrical analyses confirmed excitotoxic lesion of the entorhinal cortex after 3 months and showed a decrease of acetylcholineste-rase-stained fibers in the stratum moleculare of the dentate gyrus and the stratum radiatum of the CA3 field. This study demonstrates the importance of the entorhinal cortex in the hippocampal cholinergic function which appears to be important to memory and learning, and raises the possibility that memory deficit in Alzheimer's disease may be associated with partial neuronal loss in the entorhinal cortex.

Acetylcholinesterase↗
PubMed1996

Expansive cervical laminoplasties--observations on comparative changes in spinous process lengths following longitudinal laminal divisions using autogenous bone or hydroxyapatite spacers.

Expansive laminoplasty is devised to preserve the posterior structures, including the original length of the spinous process which anchors the nucheal muscles, in order to prevent the postoperative development of instability and cervical kyphosis due to structural loss and poor tone of the nucheal muscles, which can result in late neurological regression after laminectomy for cervical myelopathy. We retrospectively compared the length of the spinous process at the time of follow-up with that within 3 months postoperatively using CT images. The shortening was observed in 80% of 60 spinous processes in 13 patients, where a hydroxyapatite (HA) block was used as a spacer placed between the two sides of the split spinous process. The incidence was 9% of 22 spinous processes in six patients where auto bone graft (ABG) was used as a spacer, and the difference was significant (P < 0.01, Chi-square test). Although the usage of HA has the advantage of being less invasive than ABG, it may jeopardize the biomechanical function of nucheal muscles due to reduction in the original length of the spinous process.

Adult↗
PubMed1996

Synthesis of a squash-type protease inhibitor by gene engineering and effects of replacements of conserved hydrophobic amino acid residues on its inhibitory activity.

Cucurbita maxima trypsin inhibitor I (CMTI-I), a member of the squash-type protease inhibitor family, is composed of 29 amino acids and shows strong inhibition of trypsin by its compact structure. To study the structure-function relationship of this inhibitor using protein engineering methods, we constructed an expression system for CMTI-I as a fused protein with porcine adenylate kinase (ADK). A Met residue was introduced into the junction of ADK and CMTI-I to cleave the fusion protein with CNBr, whereas a Met at position 8 of authentic CMTI-I was replaced by Leu. Escherichia coli JM109 transformed with the constructed plasmid expressed the fused protein as an inclusion body. After cleavage of the expressed protein with CNBr, fully reduced species of CMTI-I were purified by reversed-phase HPLC and then oxidized with air by shaking. For efficient refolding of CMTI-I, we used 50 mM NH4HCO3 (pH 7.8) containing 0.1% PEG 6000 at higher protein concentration. Strong inhibitory activity toward trypsin was detected only in the first of three HPLC peaks. The inhibitor constant of CMTI-I thus obtained, in which Met8 was replaced by Leu, was 1.4 x 10(-10) M. The effect of replacement of Met with Leu at position 8 was shown to be small by comparison of the inhibitor constant of authentic CMTI-III bearing Lys at position 9 (8.9 x 10(-11) M) with that of its mutant bearing Leu at position 8 and Lys at position 9 (1.8 x 10(-10) M). To investigate the role of the well conserved hydrophobic residues of CMTI-I in its interaction with trypsin, CMTI-I mutants in which one or all of the four hydrophobic residues were replaced by Ala were prepared. The inhibitor constants of these mutants indicated that those with single replacements were 5-40 times less effective as trypsin inhibitors and that the quadruple mutant was approximately 450 times less effective, suggesting that the hydrophobic residues in CMTI-I contribute to its tight binding with trypsin. However, each mutant was not converted to a temporary inhibitor.

Chromatography, High Pressure Liquid↗
PubMed1996

Management of psychiatric symptoms of Parkinson's disease.

Depression and hallucination are the two main psychiatric symptoms in parkinsonian patients. Depressive features in Parkinson patients are very close to those of endogenous depression, except for a relative lack of anxiety, irritability, suicidal ideations, delusions and circadian rhythm. Pharmacotherapy with antidepressants is most reliable in the treatment of parkinsonian depressives, although levodopa or other antiparkinsonian drugs may relieve a depression. Hallucinatory complications of long-term antiparkinsonian treatment appear in two types of symptoms: (1) hallucinosis type-vivid visual hallucination and illusion with clear consciousness and well-preserved orientation, and (2) delirium type-less vivid visual hallucination and illusion with disturbed orientation and confusion. Antipsychotic drugs and 'drug holiday' are recommended for the management of hallucinations as side effects of antiparkinsonian drugs.

Adult↗
PubMed1996

Japanese siblings with missense mutation (717Val --> Ile) in amyloid precursor protein of early-onset Alzheimer's disease.

We report Japanese siblings with the missense mutation 717Val --> Ile in the amyloid precursor protein. The maternal grandmother died of an unknown dementing disorder. The proband's mother had gradually increasing amnesia beginning at age 64, which was diagnosed as Alzheimer's disease (AD). She died in a psychiatric hospital (duration of illness: 16 years). Both the proband and her elder sister were affected at about age 55 years. Disturbances of memory, judgment, and emotion, as well as personality changes, occurred first, with dementia eventually predominating. The elder sister died of pneumonia (duration of illness: 9 years). The amyloid precursor protein (APP) gene was analyzed from each sibling. Genomic DNAs obtained from blood samples were amplified by the polymerase chain reaction (PCR) method. PCR products were digested with the restriction enzyme Bcl I. The resulting restriction fragment length polymorphisms (RFLPs) showed the missense mutation 717Val --> Ile in both patients, but not in a normal control. DNA sequencing showed the presence of the 2149G --> A missense mutation only in the patients. We conclude that this familial AD may originate from the missense mutation 717Val --> Ile in the amyloid precursor protein gene and that the clinical picture is typical of AD, except for normal-pressure hydrocephalus and psychiatric phenomena.

Age of Onset↗
PubMed1996

Apoptosis in the chicken bursa of fabricius induced by X-irradiation.

Immature B lymphocytes in the chicken bursa of Fabricius have previously been reported to undergo apoptosis by low doses of ionizing radiation. In the present study, newly hatched chickens were subjected to whole-body X-irradiation, and the bursa of Fabricius was examined at various postirradiation times by light and electron microscopy to obtain information on the change of ultrastructure of irradiated bursal cells as well as on the time course and dose-response for the induction of apoptosis. Histological examination by light microscopy showed that pyknotic cells started to increase in the bursa within a few hours after irradiation and the frequency of occurrence reached a maximum at 6 hr. An evident increase of the pyknotic cells in number was observed at a dose of as little as 1 Gy, and the frequency increased with increases in the dose, reaching over 90% at 15 Gy. Electron microscopy of the irradiated bursa revealed typical apoptotic morphology such as chromatin condensation, nuclear fragmentation, formation of apoptotic bodies and phagocytosis of pyknotic cells. Induction of apoptosis was also confirmed by the appearance of a typical DNA ladder pattern on agarose gel. Thus, the present results demonstrate that the chicken bursal cells are hypersensitive to X-irradiation with regard to induction of apoptosis, and that the apoptotic bursal cells exhibit most of the ultrastructural features known to be typical of apoptosis.

Animals↗
PubMed1996

[Changes in symptoms after the great Hanshin Earthquake in patients with dementia].

Factors related to changes in symptoms after the great Hanshin Earthquake in patients with dementia were studied. Interviews were conducted with family members of thirty patients given the diagnosis of dementia at the Center for Elderly Dementia of Hyogo College of Medicine between August 1993 and December 1994. The earthquake occurred on January 17, 1995, and the interviews were conducted three months later. Patients were classified into two groups: Group 1: those whose symptoms changed after the earthquake (n = 13); Group 2: those whose symptoms did not change after the earthquake (n = 17). Symptoms were exacerbated within 1 week after the earthquake. The percentage of patients with mild dementia was higher in Group 1 than in Group 2. Scores on the Mini-Mental State examination and on Hasegawa's dementia scale were lower in Group 2 than in Group 1. On a modified GBS-scale, patients in Group 2 scored higher than those in Group 1 in impaired intellectual function and in reduced motivation, and they scored lower than those in Group 1 in impaired emotional function. CT scans showed that cortical atrophy and ventricular enlargement were greater in Group 2 than in Group 1. These findings suggest that after the earthquake symptoms became more severe in patients with mild dementia at an early stage, who have anxiety, irritability, and emotional lability.

Aged↗
PubMed1996

Regional vascular effects of MPC-1304, a novel dihydropyridine derivative, in conscious normotensive and spontaneously hypertensive rats.

The purpose of this study was to compare the regional vascular effect of a novel dihydropyridine derivative, MPC-1304 [(+/-)- methyl-2-oxopropyl-1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-3, 5-pyridinedicarboxylate], with that of nifedipine and manidipine in conscious spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). The radioactive microsphere technique was used to measure systemic and regional hemodynamic parameters before and 1 hr after p.o. administration of drugs. In SHR, MPC-1304 at a dose of 1 mg/kg reduced the mean blood pressure and systemic vascular resistance and increased cardiac output, as did nifedipine (10 mg/kg) and manidipine (3 mg/kg). MPC-1304, as well as nifedipine, significantly increased the blood flow in pulmonary, gastric, small intestinal and skeletal muscular beds and reduced their vascular resistance. Manidipine increased regional blood flow only in small intestinal and skeletal muscular beds. Only MPC-1304 increased the renal blood flow. In WKY, MPC-1304 and nifedipine reduced the mean blood pressure and systemic vascular resistance to lesser degrees than in SHR. Both drugs significantly increased coronary and skeletal muscular blood flow. MPC-1304 significantly reduced the renal blood flow without altering renal vascular resistance, in striking contrast to its renal effect in SHR. These findings suggest that MPC-1304 possesses a genetic hypertension-dependent renal vasodilating action, unlike nifedipine and manidipine. One possible mechanism for this difference in the effect on renal circulation between SHR and WKY may involve the potent antagonizing effects of MPC-1304 on alpha-2 adrenoceptor-mediated vasoconstriction.

Animals↗
PubMed1996

[Magnetic resonance studies of dentato-rubro-pallido-luysian atrophy--correlation with clinical severity and age of onset].

Dentato-rubro-pallido-luysian atrophy (DRP-LA) is a rare autosomal dominant neurodegenerative disorder. Recently the genetic abnormality has become clear. We encountered four patients with DRPLA (including a 14-year-old boy and his father) in whom the final diagnosis was made by DNA analysis. In addition to performing conventional MRI, we quantified brain metabolites by proton MR spectroscopy. We also compared the expanded repeat size of CAG trinucleotide in a gene on the short arm of chromosome 12 to the MR findings which consisted of the findings of clinical severity and age of onset. The method reported by Nagafuchi et al. was used to determine the size of the CAG repeat on the focus chromosome. Repeat size was closely correlated with age at onset and disease severity. The MR studies were performed with a Magnetum H-15SP (Siemens, 1.5 Tesla) equipped with a C-P type head coil. Axial T2-WIs (TR = 2000 ms, TE = 90 ms) and T1-WIs (TR = 200 ms, TE = 15 ms) were measured. Atrophy of the brainstem, the tegmentum, and the cerebellum, and periventricular hyperintensity could be seen. The sequence for 1H-MRS was PRESS, voxel size was 8 ml, and regions of interest were placed on right basal ganglia and right parietal white matter. After compensating the observed signals, we obtained metabolite concentrations by using compensated water intensity as an internal standard. Despite the absence of abnormalities of the basal ganglia on MRI, NAA concentrations differed from patient to patient and were low in severe clinical cases. We propose that the CAG repeat size of the focus chromosome and NAA concentration quantified by 1H-MRS are closely correlated with clinical severity and age of onset. In conclusion, DNA analysis may be useful in early diagnosis and 1H-MRS can detect metabolic abnormalities non-invasively even when no markedly abnormal findings can be detected with other clinical modalities.

Adolescent↗
PubMed1996

[A case of endobronchial tuberculosis with peripheral mucoid impaction showing a solitary pulmonary nodular shadow].

In a 70-year-old nonsmoking, asymptomatic man, chest radiography before a operation for early gastric cancer revealed a solitary nodular shadow in the right lower lobe. Laboratory studies for bacteria and mycobacteria were negative and histological diagnosis could not be obtained. Right lower lobectomy was performed because the mass could be malignant. Histologically the right B10 was almost completely obstructed by tuberculous granuloma and the distal bronchus were dilated containing inspissated mucus. The abnormal nodular shadow was considered the obstructive mucoid impaction secondary to tuberculous bronchitis. It is quite rare that solitary nodular shadow is found in such a case of endobronchial tuberculosis.

Aged↗
PubMed1996

Clinical study of chronic tonsillitis with IgA nephropathy treated by tonsillectomy.

Over the past 5 years, bilateral tonsillectomy has been performed in 104 patients (48 male and 56 female) with IgA nephropathy at the Department of Otolaryngology of Sendai Red Cross Hospital. We studied the relationship between remission rates as shown by urinary findings at one year after tonsillectomy and various clinical factors. Patients with mild or moderate renal pathology had higher postoperative remission rates of proteinuria than those with advanced renal pathology. There was a tendency for higher remission rates in patients with smaller tonsils. There were no significant differences relative to past history of tonsillitis, age, pus plugs in the lacunae, temporary deterioration of urinary findings after tonsillectomy, and results of provocation tests.

Adolescent↗