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Biomedical subjects

M Kato

Publications and source records attributed to M Kato.

At least 397 records · Page 22Linked to original sources
PubMed2000

Impaired heart rate response during incremental exercise in patients with acute myocardial infarction and after coronary artery bypass grafting: evaluation of coefficients with Karvonen's formula.

Heart rate (HR) response during exercise in patients with ischemic heart disease was evaluated, and the appropriateness of Karvonen's method for determining rehabilitation exercise target HR was investigated. The study group comprised 24 patients with acute myocardial infarction (AMI) and 37 patients who had undergone coronary artery bypass grafting (CABG). Cardiopulmonary exercise testing (CPX) was performed with a cycle ergometer and changes in HR (deltaHR)/changes in work rate (deltaWR) and interval changes of the coefficient of Karvonen's formula were evaluated. In the AMI group and the CABG group, deltaHR/deltaWR were significantly lower than those of age-matched control subjects (p<0.01). Karvonen's coefficients ranged from 0.37 to 0.54 when calculated from actual peak HR and 0.21 to 0.32 calculated from the predicted peak HR. An impaired HR response was found in patients with AMI and those who had had CABG up to 6 months previously. Because the Karvonen's coefficient values, which ranged from 0.6 to 0.8, were elevated for these patients, and considering the data from the CPX, increased exercise is recommended for such cases.

Adrenergic beta-Antagonists↗
PubMed2000

Cardiac angiotensin II receptors are downregulated by chronic angiotensin II infusion in rats.

We studied the effect of chronic (7 days) angiotensin II infusion in a subpressor (200 ng/kg per minute) dose on angiotensin II receptors in the left ventricle in rats. Infusion of angiotensin II caused an elevation in systolic blood pressure after 3 days, usually to values of about 150 mmHg, and the increase continued during the drug administration. The number of angiotensin II type 1 and angiotensin II type 2 receptors was significantly decreased by 20-30% in the angiotensin II-infused left ventricular membranes without affecting the affinity. Thus, these data suggest that angiotensin II may regulate the number of its own receptors in rat left ventricles.

Angiotensin II↗
PubMed2000

Recognition of receptor lipopolysaccharides by spike G protein of bacteriophage phiX174.

The spike G protein of bacteriophage phiX174 was prepared as a hexa histidine-tagged G protein (HisG). In the enzyme-linked plate assay, HisG bound specifically to lipopolysaccharides (LPSs) of the phiX174-sensitive strains, and did not bind to LPSs of the phiX174-insensitive strains. The truncated G protein obtained after trypsin digestion of HisG had the similar affinity to the LPSs to HisG, indicating that eight amino acid residues from the N-terminus are not essential to the binding with the LPSs.

Bacteriophage phi X 174↗
PubMed2000

Subsite structure and catalytic mechanism of a new glycosyltrehalose-producing enzyme isolated from the hyperthermophilic archaeum, Sulfolobus solfataricus KM1.

A glycosyltrehalose-producing enzyme from Sulfolobus solfataricus KM1 catalyzes a conversion of maltooligosaccharides to glycosyltrehaloses and also hydrolyzes maltooligosaccharides to liberate glucose, as a side reaction. From the sum of the conversion and hydrolysis reaction rates, the rate parameters involved in the "splitting" of the alpha-1,4 glucosidic linkage were calculated. From the data obtained, the subsite structure for maltooligosaccharides was identified. From the analysis of the hydrolysate of maltotriose in [18O labeled H2O, the hypothesis of the C1-O bond splitting and the formation of a glycosyl (maltosyl)-enzyme intermediate was strongly supported. From the analysis of the reaction product in the presence of [3H] labeled glucose, the occurrence of intermolecular transglycosylation was confirmed. These data strongly support the suggestion that the catalytic mechanism of this enzyme is a transglycosylation.

Catalysis↗
PubMed2000

A simple and rapid method for the preparation of a cell-free extract with CCAAT-binding activity from filamentous fungi.

A simple and rapid method for the preparation of a cell-free extract with the CCAAT-binding activity was established with Aspergillus nidulans as a model fungus. Proteins were extracted with 6 M guanidine hydrochloride directly from mycelia and renatured by dialysis. This method was found applicable to other filamentous fungi such as Aspergillus oryzae and Trichoderma viride.

Aspergillus↗
PubMed2000

Nuclear transfer in cattle : effect of linoleic acid-albumin on freezing sensitivity of enucleated oocytes.

The effect of linoleic acid-albumin (LAA) supplementation to the media for IVM, enucleation, and activation on the developmental potential of bovine embryos produced by nuclear transfer (NT) into frozen-thawed cytoplasts was investigated. Blastomeres derived from morulae was placed in the perivitelline space of frozen-thawed cytoplasts, which were then fused by a DC pulse. The proportion of fused embryos was similar between groups with and without LAA (87 vs. 90%). The proportion of development to blastocysts of NT embryos derived from the media with LAA (14%) was higher than that without LAA (4%), indicating that LAA treatment of bovine oocytes during IVM, enucleation and activation can improve the ability of such cytoplasts after freezing and thawing to develop into blastocysts after NT.

Albumins↗
PubMed2000

Theophylline for the treatment of bronchial asthma: present status.

Current Japanese asthma guidelines recommend theophylline as an additional regimen to inhaled beta-agonists (on demand use) and inhaled corticosteroids (beclomethason dipropionate 200-1200 micrograms/day or fluticason propionate 200-800 micrograms/day) for patients whose asthma is not controlled completely. Similar recommendations are made in the International Consensus Report on Diagnosis and Treatment of Asthma. Recent advances in the understanding of its actions, especially regarding the antiinflammatory and immunomodulatory effects of low doses of theophylline, encourage its appropriate use in asthma treatment. Furthermore, asthma and chronic obstructive pulmonary disease (COPD) are considerably common diseases, and the economic benefits associated with the use of a relatively inexpensive, once or twice daily oral drug (intravenous infusion, if necessary) could be of importance. But, because of its narrow therapeutic range, dosage must be individualized in order to optimize the treatment based on the measurement of theophylline concentration in serum. Theophylline is an old medication with new forms. When used effectively and safely, it can have significant clinical benefits for patients. This paper intends to review the effectiveness of theophylline--historically and contemporarily.

Animals↗
PubMed2000

The preventive effect of magnesium on coronary spasm in patients with vasospastic angina.

STUDY OBJECTIVES: Previous studies have reported that magnesium (Mg) deficiency is associated with coronary spasm. However, little is known about the preventive effect of Mg on coronary spasm. The present study investigated whether Mg prevents coronary spasm in patients with vasospastic angina (VSA). DESIGN: Effectiveness trial. SETTING: University medical center. PATIENTS: Twenty-two patients with VSA. INTERVENTION: Coronary spasm was induced with an intracoronary infusion of acetylcholine (Ach). After spontaneous relief of the coronary spasm, Mg sulfate (0.27 mmol/kg body weight) was infused IV over 20 min in 14 patients and isotonic glucose was infused in 8 patients as control subjects. Intracoronary infusion of Ach was then repeated, and the diameter of the coronary arteries was measured quantitatively. MEASUREMENTS AND RESULTS: Mg infusion caused coronary artery dilatation at baseline in both the spastic (5. 9 +/- 2.3%) and nonspastic segments (5.5 +/- 1.5%). Mg infusion reduced the severity of chest pain and ST-segment deviations during coronary spasm. After the Mg infusion, the percent change in the diameter of the spastic segments improved from - 62.8 +/- 2.6% to - 43.7 +/- 4.7% during coronary spasm. Overall, 10 of 14 patients (71%) responded favorably to Mg infusion. Isotonic glucose infusion did not elicit changes in chest pain severity, ST-segment deviations, or the diameter of the coronary arteries during spasm. CONCLUSIONS: Mg infusion produces nonsite-specific basal coronary dilatation and suppresses Ach-induced coronary spasm in patients with VSA.

Acetylcholine↗
PubMed2000

Bronchial hyperresponsiveness before and after the diagnosis of bronchial asthma in children.

OBJECTIVE: To assess at what age bronchial hyperresponsiveness (BHR) is acquired in children with asthma. BACKGROUND: A relationship between BHR and infantile wheezing diseases has been reported. Infants with a genetic predisposition to atopy are more likely to wheeze with respiratory viral infection or bronchiolitis, and it is suspected that the continued BHR after the first attack of asthma may be induced or triggered by some viral infections. Also, recent studies have reported the existence of atopic and BHR-related genes. However, whether BHR is congenital or acquired after asthma attacks, and when BHR in children with asthma is established or acquired remain unclear. METHODS: We performed methacholine inhalation challenge using a transcutaneous oxygen pressure (tcPO(2)) monitoring system in 205 children without asthma from 6 months to 6 years of age. During follow-up, 18 of these participants were diagnosed with asthma (group N-A). This group and 15 age-matched children without asthma (group N-N) were tested twice using methacholine inhalation challenge. For comparison, 39 age-matched atopic-type asthmatic children (group A-A) were also given the inhalation challenge twice. Methacholine inhalation challenge using a tcPO(2) monitoring system was performed while the participants were asleep in the supine position. Sequential doses of inhaled methacholine delivered by oxygen mask were doubled until a 10% decrease in tcPO(2) from the baseline was reached. The cumulative dose of methacholine at the inflection point of tcPO(2) (minimal dose of methacholine [Dmin]-PO(2)) was considered to represent BHR. RESULTS: In groups N-N and A-A, there was no difference in Dmin-PO(2) between the first and second challenge. However, the Dmin-PO(2) in group N-A significantly decreased from the first challenge to the second challenge. There was no significant difference between the Dmin-PO(2) in group N-N and the first Dmin-PO(2) in group N-A; or between the Dmin-PO(2) in group A-A and the second Dmin-PO(2) in group N-A. CONCLUSIONS: These data suggest that BHR in many infants with asthma is acquired after several asthma attacks.bronchial hyperresponsiveness, childhood asthma, methacholine inhalation challenge, transcutaneous oxygen pressure.

Asthma↗
PubMed2000

Celiac plexus block in cancer pain management.

The neurolytic celiac plexus block (NCPB) has been recommended for pain relief in patients with upper abdominal cancer by the WHO Cancer Pain Relief Program. In this article, we review the indications, techniques, and adverse effects of NCPB based on the previous findings in the literature and our own experience of 142 NCPBs during the past 11 years. No well-validated indication criteria for the NCPB have been available from invasive trials or non-invasive pain evaluations. Thus, the procedure has been employed using comprehensive pain assessment. Several modified approaches have been described for NCPB with differences in the target space where the alcohol is injected (precrural and retrocrural) and the insertion route of the needle (posterolateral and transdiscal). We have used the retrocrural transdiscal approach because of its simplicity and safety. The efficacy of the resultant pain relief does not differ among these techniques. Therefore, whether a distinction exists between blocks of the celiac plexus and those of the splanchnic nerves is controversial. The term "peri-aortic nerve block" may better describe the feature of this neurolytic intervention. The noteworthy adverse effects of alcoholic neurolysis include regional pain, hypotension, diarrhea, hypoxemia, and acute alcoholic intoxication. Most of them are transient and controllable. The diarrhea may counteract the morphine-induced constipation. NCPB relieves visceral pain in upper abdominal cancer with no serious adverse effects. We recommend this procedure to improve the quality of life of the patients suffering from abdominal cancer pain.

Abdominal Neoplasms↗
PubMed2000

Epidemiological studies of coincidental outbreaks of enterohemorrhagic Escherichia coli O157:H7 infection and infectious gastroenteritis in Niimi City.

A sharp rise in the number of patients with infectious gastroenteritis was observed in the 25th week of year 1996 in the Takahashi-Ashin district by researchers with the Infectious Disease Surveillance Program for tuberculosis and other infectious diseases in the Okayama Prefecture. This sharp rise occurred coincidentally with an outbreak of enterohemorrhagic Escherichia coli O157:H7 (EHEC O157) infection in Niimi City of the Takahashi-Ashin district. However, this phenomenon of coincidental outbreaks was not observed during the outbreak of EHEC O157 infection in Oku Cho. By reviewing outpatients' charts in a sentinel hospital in Niimi City for the Infectious Disease Surveillance Program, it was noted that patients with acute gastrointestinal infection visiting the hospital during the increased incidence of infectious gastroenteritis may have been included as misclassified cases of EHEC O157 infection. On the other hand, the exponential probability plotting of symptomatic patients with EHEC O157 infection in Niimi City revealed a breaking point which suggested a dual exposure to contaminated food or an overlap with other acute gastrointestinal infections. The latter possibility was discounted, because stool culture-positive patients with EHEC O157 infection also exhibited a similar breaking point, and furthermore, the coincidental increase in infectious gastroenteritis in the same area was attributable to the EHEC O157 infection. The present study demonstrates the association between the sharp rise in gastroenteritis and the outbreak of EHEC O157 in the Takahashi-Ashin district. A careful analysis of the cases of infectious gastroenteritis by the Infectious Disease Surveillance Program would have predicted the outbreak of EHEC O157.

Disease Outbreaks↗
PubMed2000

Cowden's disease diagnosed through mucocutaneous lesions and gastrointestinal polyposis with recurrent hematochezia, unrevealed by initial diagnosis.

A 51-year-old man was admitted to our hospital because of hematochezia and painful keratotic plaques involving both hands. He had gastrointestinal polyposis, and a history of liver hemangiomas and thyroid tumor. Numerous papules on the face and papillomatosis on the oral mucosa were present. A diagnosis was made as a typical case of Cowden's disease according to the criteria proposed by Salem and Steck (J Am Acad Dermatol 8: 686, 1983). The patient was not correctly diagnosed initially in spite of typical manifestations of Cowden's disease, mainly due to his concomitant manifestations which occurred chronologically.

Diagnostic Errors↗
PubMed2000

Gastrointestinal stromal tumors of the small intestine that expressed c-kit protein.

We report two patients with gastrointestinal stromal tumors (GISTs) of the small intestine that expressed c-kit protein (CD117). One was a 68-year-old woman with epigastralgia and vomiting. A submucosal tumor of the upper jejunum was detected, and partial resection was carried out. The histology revealed a GIST negative for CD34 but positive for CD117. The other was a 42-year-old woman with progressive anemia, melena and lower abdominal pain. Intussusception was detected, and a partial resection was carried out. A submucosal tumor of the lower jejunum was noted. The histology revealed a GIST positive for both CD34 and CD117.

Adult↗
PubMed2000

Reversibility of serum NH3 level in a case of sudden onset and rapidly progressive case of type 2 citrullinemia.

A 48-year-old male presented with an acute change in mental status due to a marked elevation of plasma NH3 and was diagnosed with citrullinemia with amino acid analysis of blood. Hemodialysis and hemodiafiltration were performed, but serum chemical analysis did not show any improvement which led us to terminate dialysis following intensive care for 3 days. Surprisingly, NH3 level had decreased by 6 days after admission, coinciding with normalization of the size of the pupils. Since spontaneous remission had never been discussed, we discuss this relatively rare, but clinically significant entity with regard to its acute phase management and its potential reversibility.

Ammonia↗
PubMed2000

Management of severe neutropenia with cyclosporin during initial treatment of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis.

Severe neutropenia (absolute neutrophil count <500/gl) is probably due to the combined effects of dysregulated cytokine production and chemotherapeutic agents, and is one of the risk factors in the initial treatment of patients with Epstein-Barr virus-related hemophagocytic lymphohistiocytosis (EBV-HLH). We report here 9 cases of neutropenic HLH, of which 8 were treated with cyclosporin (CSA, 2-6 mg/kg/day; continuous infusion, or 6 mg/kg/day; per os, for periods ranging from 9 days to >8 weeks) in the initial neutropenic phase during induction treatment using corticosteroids and etoposide. Five of the 6 cases, in which CSA treatment was started early (before the second week of induction), survived the critical period with recovery of neutrophil counts within a week. The remaining 3 cases, in which CSA was introduced later or not at all, died of infection. Based on these results, we recommend a prompt short-term CSA infusion during neutropenic episodes in the most common treatment regimen of etoposide and corticosteroids in patients with HLH. Improved neutrophil recovery as a result of CSA treatment makes it possible to continue immunochemotherapy safely and obtain improved patient outcomes.

Adolescent↗
PubMed2000

Increased midkine expression in hepatocellular carcinoma.

CONTEXT: Midkine (MK) is a novel heparin-binding growth factor whose gene was identified in embryonal carcinoma cells in early stages of retinoic acid-induced differentiation. OBJECTIVE: To examine the overexpression of MK in hepatocellular carcinoma (HCC). METHODS: Seventy-seven primary HCC specimens from patients aged 17 to 72 years (63 men and 14 women) were examined. Histologically, 16 cases of HCC were classified as the well-differentiated type, 50 cases as the moderately differentiated type, and 11 cases as the poorly differentiated type. Immunohistochemical analysis was performed using a rat immunoglobulin G2a monoclonal antibody against the carboxyl terminal region of human MK. In situ hybridization was also performed on 20 HCC samples. RESULTS: We successfully applied this monoclonal antibody against MK to analyze archival paraffin sections. The cancer tissues showed a positive reaction to this antibody, in which there was an intense reaction in their cytoplasm. Approximately one third of the individuals with HCC (26/77) had tumor cells that expressed MK, and these were classified into the following types: moderately differentiated (20/50), well differentiated (3/16), and poorly differentiated (3/11). The in situ hybridization analysis revealed that the signals of MK transcripts were found in the cytoplasm of the cancer cells; the distribution and localization of the MK transcripts' signals determined by in situ hybridization analysis were similar to those obtained by immunohistochemical analysis. CONCLUSIONS: Hepatocellular carcinoma expressed increased MK at the messenger RNA and protein level.

Adolescent↗