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Biomedical subjects

K Miyagi

Publications and source records attributed to K Miyagi.

At least 55 records · Page 3Linked to original sources
PubMed1997

Acceleration of stiffness in underperfused diabetic rat hearts by glyburide, a KATP channel blocker, and its prevention by levcromakalim and insulin.

OBJECT: To clarify the role of the KATP channels in myocardial dysfunction during underperfusion with norepinephrine (NE) in the diabetic heart, particularly the heart treated with sulphonylurea derivatives. METHODS: Isolated 6-week streptozotocin-diabetic rat hearts with a balloon in the left ventricle (LV) were paced and perfused with normoxic Krebs-Henseleit solution. Agents were infused for 15-25 min before as well as during 60-min underperfusion (2 ml/min/g heart weight) with 10(-6) M NE. Regional myocardial flow distribution was measured using dye microspheres. The effects of ex vivo glyburide (10(-6) M, a sulphonylurea anti-diabetic drug and a specific KATP channel inhibitor) on contractile dysfunction and abnormal regional myocardial energy metabolism were examined during underperfusion with NE in the absence of presence of levcromakalim (10(-4) M, a selective K+ channel opener) and insulin (2 mU/min/g heart weight). RESULTS: The flow rate was greater in the LV subendocardium than the subepicardium during normal perfusion, and smaller at 60-min underperfusion with NE. The LV diastolic tension and pressure during underperfusion with NE increased more rapidly in the presence of glyburide. At 60-min underperfusion with NE, the diastolic pressure elevation was still higher in the glyburide-treated heart, and decreases in tissue ATP, creatine phosphate (CP), energy charge, phosphorylation potential and CP/inorganic phosphate (P(i)) ratio, and increases in AMP, P(i) and lactate were more marked in the glyburide-treated heart, particularly in the LV subendocardium. Thus, ex vivo glyburide enhanced the increase in LV stiffness and abnormal myocardial energy metabolism during underperfusion with NE in diabetic hearts. These changes were reduced by levcromakalim to the level during underperfusion with NE without glyburide. Insulin did not prevent the glyburide-induced earlier exacerbation of the increase in LV stiffness during underperfusion with NE, but reduced the detrimental effects 20 min after the onset of underperfusion. CONCLUSIONS: KATP channels in the diabetic myocardium probably open during underperfusion with NE, and it helps delay the initiation of the increase in cardiac stiffness. Glyburide may have harmful effects in the ischemic diabetic heart; the myocardial KATP channel blockade during underperfusion with NE enhanced the increase in LV stiffness and abnormal myocardial energy metabolism. The glyburide-induced detrimental effects in the ischemic diabetic heart are prevented by levcromakalim and partly by insulin.

Animals↗
PubMed1997

[Incidence of Kanagawa phenomenon-positive and -negative Vibrio parahaemolyticus strains isolated from traveller's diarrhea and their relation to tdh and trh genes].

A total of 1,319 strains of Vibrio parahaemolyticus isolated from traveller's diarrhea were analysed for Kanagawa phenomenon (KP) with the Wagatsuma blood agar test and the results were also compared with those of analyses of tdh and trh genes which encode thermostable direct hemolysin (tdh) and TDH-related hemolysin (trh). The majority of the strains (1,152 strains) counting 87.3% had positive KP, among which 1,049 and 103 strains were only tdh and both tdh and trh-positive ones, respectively. However, 167 strains counting 12.7%, which is quite high compared to the previous report, were found to have negative KP, among which 94 and 24 strains were only trh and both tdh and trh-positive ones, respectively.

Bacterial Toxins↗
PubMed1997

Role of reactive nitrogen and oxygen intermediates in gamma interferon-stimulated murine macrophage bactericidal activity against Burkholderia pseudomallei.

We examined the contributions of reactive nitrogen and oxygen intermediates (RNI and ROI, respectively) in macrophage bactericidal activity against Burkholderia pseudomallei, the causative agent of melioidosis, in order to understand host defense mechanisms against infection caused by this bacterium. The bacteria multiplied in unstimulated murine macrophage cell line J774.1. However, a strong dose-dependent inhibition of intracellular bacterial growth was observed when gamma interferon (IFN-gamma)-activated macrophages were used. The induction of bactericidal activity correlated well with the production of nitric oxide (NO) by IFN-gamma-activated macrophages and was markedly suppressed by N(G)-monomethyl L-arginine (L-NMMA), a competitive inhibitor of NO synthesis. Superoxide dismutase (SOD) and catalase significantly inhibited macrophage bactericidal activity, and the combined addition of L-NMMA, SOD, and catalase resulted in the complete inhibition of IFN-gamma-stimulated activity. The bacteria were susceptible to the killing effects of chemically generated NO and superoxide anion in a macrophage-free system. Our results indicate that IFN-gamma-induced macrophage bactericidal activity against B. pseudomallei is mediated to a large extent by RNI killing mechanisms and to a lesser extent by ROI-dependent mechanisms.

Animals↗
PubMed1997

[Studies on bacillary dysentery cases of overseas travellers--during 1979 to 1995].

A total of 36,780,440 overseas travellers during 1979-1995 (17 years) were quarantined at Osaka and Kansai Airport Quarantine Station, 84,777 travellers reported themselves suffer from diarrhoea. Stools from 29,587 persons were bacteriologically examined. Various enteropathogenic bacteria were isolated from 9,766 (33.0%) patients of the stools examined. Isolated species were as follows: Plesiomonas shigelloides (3,234 cases); Salmonella spp. (2,236 cases); enterotoxgenic Escherichia coli (1,621 cases); Vibrio parahaemolyticus (1,959 cases); and Shigella spp. (1,242 cases). 1,278 different Shigella strains were isolated from 1,242 cases who were thus diagnosed as bacillary dysentery patients. The suspected regions or countries for infection of these cases were analysed. The serovars and antibiotic-sensitivities of the isolated strains were examined. Colicine typing of S. sonnei strains were also done. The results can be summarized as follows. 1) The most cases (53.4%) were infected in India. 2) The percentage distribution of sub-species of the strains was as follows; S. sonnei (57.8%), S flexneri (29.8%), S. boydii (8.4%), and S. dysenteriae (4.0%), respectively. 3) The major colicine type of S. sonnei strains were type 6 and 0. 4) The percentage of Antibiotic-resistant strains of each sub-species was S. dysenteriae (92.2%), S. sonnei (89.4%), S. flexneri (87.1%), and S. boydii (84.9%), respectively. The percentage of Antibiotic-resistant strains of S. flexneri were increased annually.

Adolescent↗
PubMed1997

[Lymphocytic infundibulo-hypophysitis with diabetes insipidus as a new clinical entity: a case report and review of the literature].

In 1992, we reported a lymphocytic adenohypophysitis (LIH) (Neurol Med Chir). We considered this case unusual in that the case was that of a menopausal female and that it was accompanied with diabetes insipidus as classical lymphocytic adenohypohysitis (LAH). Subsequently, Ahmed reported two cases which presented a similar pathological manifestation, except for necrosis, as did our case and named them "necrotizing infundibulo-hypophysitis." Recently we encountered another similar case, which is reported hereunder. A female, 34 years of age, had suffered from headache, polyuria, and amenorrhea. CT scan showed a pituitary mass, and pituitary tumor was surgically removed transcranially at a local hospital. The pathological examination revealed the findings of chronic inflammation and necrosis. One month after the operation, however, she was an in-patient again under the suspicion of meningitis for fever and, when antibiotic therapy at the local hospital resulted in no improvement, she was referred to our hospital. Endocrinological studies showed low FSH, LH, ACTH and plasma cortisol level. Antibodies of serum to RNP, Sm, mitochondria, nucleus, AChR, and DNA were all negative. Because of an intrasellar mass with suprasellar extension on MRI, transsphenoidal operation was conducted four months after the initial operation. The pathological examination revealed the infiltration of lymphocytes, plasma cells, and foamy macrophages, and necrosis. After this operation, the headache was cured and the patient was discharged. Two months subsequent to the second operation, headache recurred and temporal upper quadrantic anopsia was noted. An enlarged tumor was found, but prednisolone worked to cure the pain and the visual field defect was found to have been remedied. The patient's diabetes insipidus is presently persisting, and she still relies on the use of desmopressin acetate and is still in need of cortisol replacement therapy. Including our cases, ten cases of lymphocytic hypophysitis, not related to pregnancy or delivery but with diabetes insipidus, have been reported. Several clinical and anatomical features distinguish these 10 cases from classical LAH. The classical LAH was predominantly related to pregnancy or delivery. However 6 of 10 cases were male in LIH. LAH related to pregnancy or delivery does not accompany diabetes insipidus, but all reported cases of LIH had a diabetes insipidus. Visual field and/or ocular movement disturbance are LAH's chief complaints (15 out of 25 cases) but visual field disturbance seldom occurs in LIH (1 out of 10 cases). Hypopituitarism is more serious in LAH, and 4 cases became fatal from an adrenal crisis. Anatomically, inflammatory change of LIH is located anterior and posterior to the pituitary gland and extends to the pituitary stalk and, at times, hypothalamus. On the other hand, LAH relates to pregnancy or delivery, the inflammatory change localizes to the adenohypophysis. Ahmed emphasized necrosis, while necrosis was not a prominent histological finding in LIH. Necrosis was noted only in 3 of 10 cases. To be stressed, rather, are the inflammatory changes seen on the neurohypophysis and the pituitary stalk, together with the characteristic diabetes insipidus. We believe, in view of the above, that what Ahmed named necrotizing infundibulo-hypophysitis should be named "LIH with diabetes insipidus." Whereas differential diagnosis is necessary between this said new disorder and the conventional LAH, we advocate that the latter, which is related to pregnancy or parturition but is free from neurohypophysitis be identified as "LAH related to pregnancy or delivery." With respect to treatment, steroid therapy is essential. If the symptoms do not improve, a transsphenoidal operation for diagnosis (LIH and LAH) and decompression (the case of LAH with visual or external ocular movement disturbance) is advisable. However, extensive surgery is not recommended, because per

Adult↗
PubMed1997

[A case report of surgical treatment of constrictive pericarditis with coronary artery disease].

We performed the concomitant operation for constrictive pericarditis and coronary artery disease in an octogenarian. A 82-year-old male was hospitalized with dyspnea, edema of the lower extremities and pleural effusion on chest X-ray film. Cardiac catheterization revealed constrictive pericarditis and 75% stenosis of left anterior descending artery. Extensive pericardiectomy was performed including posterior wall of left ventricle and left atrium under the beating heart by using femoro-femoral partial bypass. Single CABG with a saphenous vein graft was performed following pericardiectomy. Postoperative cardiac catheterization showed good recovery of hemodynamics and patency of the bypass graft. Postoperative course was uneventful. The patient was discharged on twenty fifth postoperative day.

Aged↗
PubMed1996

Radical open endvenectomy with autologous pericardial patch graft for correction of Budd-Chiari syndrome.

A surgical technique for the treatment of Budd-Chiari syndrome associated with vena caval obstruction has been devised. The occluded hepatic vena cava and hepatic veins were reconstructed by open endvenectomy, using an autologous pericardial patch graft and a femorofemoral bypass technique. The hepatic artery and portal vein were not controlled with vascular clamps during the surgery. Between 1979 and 1994, 29 patients were treated using this technique and achieved good results. All the patients did well with good function of the reconstructed vena cava and of the hepatic veins, and showed acceptable reduction of symptoms caused by portal hypertension and caval stagnation.

Adult↗
PubMed1996

[Bacteriological studies of travellar's diarrhoea. 5) Analysis of enteropathogenic bacteria at Osaka Airport Quarantine Station from January 1992 through September 3rd, 1994].

During the last 2 years and 8 months before the closure of Osaka Airport Quarantine Station (from Jan. 1992 to Sep. 3, 1994), a total of 7,421,909 overseas travellers were quarantined. 15,919 reported themselves of suffering from diarrhoea. Bacteriological examination of a total of 6,031 individuals' stools were performed. 1) Various enteropathogenic bacteria were isolated from 31.2% of the stools examined. Isolated species were as follows: Plesiomonas shigelloides, 1,127 cases (59.9%); Vibrio parahaemolyticus, 293 cases (15.6%); Salmonella spp., 262 cases (13.9%); Shigella spp., 235 cases (12.5%); Aeromonas sobria, 93 cases (4.9%); V. cholerae non-O1, 69 cases (3.7%). 2) The enteropathogenic bacteria were isolated through out the year without any seasonal variation. 3) The major regions where the travellers were infected with the pathogens are as follows: V. cholerae non-O1 (NAG Vibrio) and enteropathogenic Escherichia coli, South-East and South-West Asia; Vibrio other than NAG, South-East and East Asia; Shigella, widely distributed but especially in India; P. shigelloides and Salmonella, widely distributed. 4) 2 strains of toxigenic (cholera toxin-producing) V. cholerae O139 were isolated from patients who had visited Indonesia and Thailand, respectively. 5) In 320 cases (17%), plural enteropathogenic bacteria were isolated from single patients, suggesting a high frequency of the mixed infections. 6) Among Shigella strains, S. sonnei were isolated the most, followed by S. flexneri (24.7%), S. boydii (8.8%) and S. dysenteriae (2.9%). 7) Among Salmonella serovers, Salmonella Enteritidis was isolated the most frequently (39 cases, 14.1%). 8) 218 (91.6%) of 238 Shigella strains and 103 (37.6%) of 276 Salmonella strains were resistant to one or more drugs tested (SM.CP.TC.KM.ABPC.NA.OFLX). 9) All of the 22 V. cholerae O1 strains were Ogawa, E1 Tor. Among them, 19 were toxigenic strains and 3 were non-toxigenic. 10) O4:K8 was the most frequently isolated serover of V. paraemolyticus. 87.4% of all V. parahaemolyticus strains were positive with thermostable direct hemolysin (TDH) gene, and 12.6% of them were positive with TDH-related hemolysin (TRH) gene by DNA-probe methods.

Diarrhea↗
PubMed1996

[Clinical experience with normothermic selective cerebral perfusion during graft replacement of ascending-arch-descending aortic aneurysms with annuloaortic ectasia].

We treated three cases of ascending-arch-descending aortic aneurysm with annuloaortic ectasia by performing graft replacement. The patients included a 34 year old female, a 34 year old male and a 42 year old male. In one case the aneurysm was atherosclerotic and of type I and II + IIIb dissection in the other two cases. During the operation we were able to utilize normothermic selective cerebral perfusion during construction of the left common carotid artery. Specially, normothermic partial F-F bypass and normothermic selective cerebral perfusion to the left common carotid artery were used during graft replacement from the descending aorta to the left common carotid artery. This was followed by regular hypothermic total ECC and hypothermic cerebral selective perfusion during subsequent graft replacement of the innominate artery and a modified Bentall's operation. This new protocol in which normothermic cerebral perfusion is utilized during the procedure on the left common carotid artery and hypothermic perfusion is utilized only during the subsequent procedure on the innominate artery permits significant shortening of the cardiac arrest time and cerebral perfusion time compared with when only hypothermic perfusion is used. This significant shortening contains obvious benefits in the areas of cardiac and brain protection.

Adult↗
PubMed1996

[Management of hydrocephalus in the case with pineal region tumor].

When patients have a pineal region tumor, they frequently present with hydrocephalus. However, not all of patients with pineal region tumor continue to suffer from hydrocephalus after tumor therapy. We have retrospectively studied 24 patients, and found that 20 patients (83.3%) have hydrocephalus, and 5 patients (20.8% of all cases and 25.0% of hydrocephalic cases) still have a shunt. We confirmed how fast germinoma diminished under radiation therapy. Irradiation dosage ranged between 30 and 65.8 Gy. Using 10 Gy, germinoma volume decreased to 20.2% of pre-irradiation size. Furthermore, 6 patients who did not receive surgical management for hydrocephalus before radiotherapy did not require a shunt subsequently. Therefore, we concluded that most of pineal germinoma cases do not need surgical management for hydrocephalus, except in those cases where there is pineal apoplexy and aqueductal dissemination.

Adolescent↗
PubMed1996

[The prevalence rate and etiology of severe motor and intellectual disabilities syndrome in Okinawa].

We studied sixty-three children of severe motor and intellectual disabilities syndrome aged between 3 and 5 years, who live in Okinawa. Severe motor and intellectual disabilities syndrome were defined as those who belong to classes 1 approximately 4 of Ohshima's classification (incapable of walking with IQs not more than 35). The prevalence rate was about 1.12/1,000 live births. Forty-four% of the total children belonged to class 1 of Ohshima's classification (bedridden and IQs less than 20). The factors were: congenital 31.7%, perinatal 38.1%, postnatal 14.3%, and unknown 15.9%. The perinatal factor was still relatively high as compared with the others.

Child, Preschool↗
PubMed1995

Symptomatic intraventricular arachnoid cyst in an elderly man.

A case of intraventricular arachnoid cyst in an elderly man is reported. A 63-year-old man developed a progressive gait disturbance over a five-year period. CT scan showed a large cyst in the left lateral ventricle which was negative to contrast enhancement. CT cisternography revealed gradual accumulation and more than 48 hours retention of contrast medium in the cyst. The patient underwent left frontal craniotomy, and the cyst wall was partially resected for histopathological examination. Although limit microscopic examination could not establish a diagnosis, arachnoid cyst was diagnosed by electron microscopic findings. Biochemical analysis did not detect any difference between cyst fluid and CSF obtained during surgery. It is suggested that a ball-valve mechanism caused progressive enlargement of the cyst and gradual development of symptoms in this elderly patient.

Arachnoid↗
PubMed1995

Astrocytoma linked to familial ataxia-telangiectasia.

A 7-year and 11 month-old girl with cerebellar astrocytoma linked to familial ataxia-telangiectasia (AT) is presented. She was born as the 7th girl of a woman with aortic arch syndrome. Two elder sisters of the patient have ataxia telangiectasia. She had immunodeficiency, and cerebellar ataxia, but had no oculocutaneous telangiectasia. The risk of cancer developing in AT patients is about 1,200 times greater than that in age-matched controls. With regard to central nervous system tumours, seven primary tumours have been reported, such as 3 cases of medulloblastoma and 4 cases of glioma. Members of AT families who were under the age of 45 had a risk of dying of a malignant neoplasm five times greater than in the general population. However, there were no reports of glioma in AT families. In this case, it is suggested that IgA deficiency linked to familial AT may have contributed to the development of astrocytoma.

Astrocytoma↗
PubMed1995

Thrombomodulin in the sera of patients with multiple sclerosis and human lymphotropic virus type-1-associated myelopathy.

Damage to the blood-brain barrier, which mainly consists of cerebral endothelial cells, has been demonstrated in multiple sclerosis (MS) clinically and histochemically. To investigate the endothelial cell damage, we evaluated the presence of soluble thrombomodulin in the sera of patients with MS and human T lymphotropic virus type-1-associated myelopathy (HAM) using an enzyme-linked immunosorbent assay. Serum thrombomodulin levels were significantly increased in patients with acute relapsing MS during an exacerbation and chronic progressive MS as compared with those of controls (P < 0.001, respectively). Patients with HAM also had higher serum levels of thrombomodulin than did controls (P < 0.001). There was significant difference between patients with HAM and seropositive non-HAM carriers (P < 0.01). These results suggest that the detection of serum thrombomodulin could be used as a marker of endothelial cell damage in inflammatory diseases such as MS and HAM.

Adult↗
PubMed1995

Increased levels of soluble vascular cell adhesion molecule-1 (VCAM-1) in the cerebrospinal fluid and sera of patients with multiple sclerosis and human T lymphotropic virus type-1-associated myelopathy.

We evaluated the relationship between the soluble form of vascular cell adhesion molecule-1 (sVCAM-1) and disease activity in patients with multiple sclerosis (MS) or with human T lymphotropic virus type 1-associated myelopathy (HAM), and measured levels of sVCAM-1 in their cerebrospinal fluid (CSF) and sera. Serum and CSF levels of sVCAM-1 were significantly increased in patients with acute relapsing MS during an exacerbation (P < 0.01 and P < 0.001), as well as in chronic progressive MS (P < 0.05 and P < 0.001), compared with healthy individuals and patients with other neurological diseases, respectively. Patients with acute relapsing MS during an exacerbation also exhibited significantly higher serum and CSF levels of sVCAM-1 vs. patients with acute relapsing MS in remission (P < 0.001). Significantly higher serum levels of sVCAM-1 were observed in patients with HAM vs. either healthy individuals (P < 0.01) or non-HAM carriers (P < 0.01). These results suggest that the determination of sVCAM-1 in the sera and CSF may be useful in monitoring the activity of MS and HAM.

Adult↗
PubMed1995

Role of high glycogen in underperfused diabetic rat hearts with added norepinephrine.

The relationship between cardiac dysfunction and glycogen level and/or duration of diabetes was examined during underperfusion (2 ml/min/g heart weight) with 10(-6)M norepinephrine (NE) in isolated 1- and 6-week streptozotocin-diabetic rat (diabetes mellitus, DM) hearts and non-DM hearts. Glycogen levels in non-DM and 1- and 6-week DM hearts were 85, 120, and 206 mumol/g dry weight, respectively, in the subendocardium. About 13 min after the start of underperfusion with NE, the diastolic tension in 1-week DM hearts began to increase when the glycogen level had decreased to half; in 6-week DM hearts, glycogen decreased more markedly without greater lactate accumulation, but these glycogen levels were still higher (104 mumol/g dry weight) than those in 1-week DM hearts and the diastolic tension did not increase. About 17 min after the onset of underperfusion, the glycogen decreased to the 13-min level of 1-week DM hearts (64 mumol/g dry weight) and the diastolic tension began to increase. Until 20 min after the onset of underperfusion, the injury was less in 6-week than in 1-week DM hearts. However, after 60-min underperfusion with NE, when the glycogen level was markedly low in both groups ( < 20 mumol/g dry weight), diastolic tension was increased twice as much in 6-week DM as in 1-week DM hearts and was related to the decreased subendocardial ATP level. The results indicate that the markedly high glycogen content in diabetic hearts probably helps delay the start of the increase in left ventricular (LV) stiffness during underperfusion with NE. Ultimately, however, the degree of the injury depends on the duration, i.e., the severity, of the diabetes.

Adenosine Triphosphate↗
PubMed1995

Walking exercise and improved neuropsychological functioning in elderly patients with cardiac disease.

OBJECTIVES: The present study examines the effects of exercise by walking on demented elderly patients with cardiac diseases. DESIGN: Walking exercise, mental activity and brain atrophy were assessed by using the number of steps. Hasegawa's dementia score and computed tomography, respectively. SETTING/SUBJECTS: Forty-six elderly patients with cardiac disease who were living in a metropolitan city. INTERVENTIONS: The Hasegawa dementia score was determined for each patient. The memory scores were used to divide the patients into four groups: normal, > 30.0; subnormal, 30.0 approximately 22.0; predementia, 21.5 approximately 10.5; and dementia, < 10.0. The walking exercises were performed every day. We also studied the ratio of the fullness of the brain (S1) to head size (S), represented as a percentage (S1/S x 100). We screened our patients for depression by means of a self-rating depression test. MAIN OUTCOME MEASURES: Walking exercise and improved mental activities. RESULTS: The mean numbers of the steps per day for the groups were 3386 +/- 676 (normal), 1008 +/- 193 (subnormal), 1597 +/- 661 (pre-dementia) and almost no walking (dementia). The mean values of the S1/S ratio for the first three groups were as follows: normal, 84.8 +/- 3.2; subnormal, 79.2 +/- 4.3; and predementia, 76.8 +/- 4.9. Only one patient was positive with regard to the depression test. CONCLUSIONS: The mental activity of elderly cardiac patients with dementia and/or brain atrophy improved with exercise from walking.

Aged↗