Search PubMed⌕ Search

Biomedical subjects

K Takehana

Publications and source records attributed to K Takehana.

At least 37 records · Page 2Linked to original sources
PubMed1999

Morphological and histochemical analysis of a case of superficial digital flexor tendon injury in the horse.

This report compares the morphology and the concentrations of glycos-aminoglycans (GAGs) in an injured superficial digital flexor tendon (SDFT) of a horse with those of a normal tendon. An injured 6-year-old male Thoroughbred exhibited heat and swelling around the SDFT of the right forelimb. On histopathological examination, exuberant granulation was observed in the affected tendon, with activated tenocytes, angiogenesis, haemorrhage, and infiltration of small numbers of leucocytes. The collagen fibres were loosely packed and irregularly arranged. The diameter of control collagen fibrils was 20-360 nm and that of affected collagen fibrils 20-240 nm. In the analysis of GAGs in the matrix, hyaluronic acid (HA), dermatan sulphate (DS), and chondroitin sulphate (CS) were found to be major components in both control and affected tendons. Increases in DS in the affected tendon were striking. Our observations suggest that fibrillogenesis was activated by increases in DS and decreases in HA and CS. It is also assumed that absence of collagen fibrils of normal thickness and in a parallel arrangement reflected the morphological and biochemical characteristics of fibrillogenesis in the injured tendon. If the inflammatory features of an injured tendon could be altered, it might return eventually to its normal structure.

Animals↗
PubMed1999

Clinical significance of denervated but viable myocardium in patients with recanalized acute myocardial infarction.

In patients with acute myocardial infarction (MI), myocardial sympathetic innervation evaluated by 123I-metaiodobenzylguanidine myocardial scintigraphy is more sensitive to ischaemia than the associated perfusion abnormality of 201Tl myocardial scintigraphy. The purpose of this study was to evaluate the scintigraphic indices related to the recovery of left ventricular function after acute MI. 123I-metaiodobenzylguanidine and 201Tl-chloride imaging were performed in 15 patients (mean age 60 years, 13 men and 2 women) 2 weeks after the onset of acute MI. Using a 20-segment visual interpretation of the 201Tl image, myocardial segments were classified into persistent defect, redistribution or reverse redistribution, and normal 201Tl uptake. The extent of denervated segments showed a fair correlation with the ejection fraction on admission (r = -0.53, P = 0.04), whereas the extent of persistent defect had a close correlation with the ejection fraction at 4 months (r = -0.79, P = 0.01). There was a good correlation between the extent of denervated but viable myocardium and the change in ejection fraction from admission to 4 months (r = 0.68, P = 0.01). Thus, denervated but viable myocardium is a scintigraphic index related to the functional recovery of left ventricular pump function after acute MI.

3-Iodobenzylguanidine↗
PubMed1999

Scintigraphic predictor of left ventricular size after acute myocardial infarction.

The aim of this study was to evaluate the relation between thallium-201 scintigraphic indices and left ventricular size after acute myocardial infarction. Forty-seven patients with acute myocardial infarction underwent rest-redistribution thallium-201 scintigraphy at 2 weeks and left ventriculography at 4 weeks, after the onset of myocardial infarction. Percent (%) fixed defect, %redistribution and %reverse redistribution, calculated as a percentage of whole left ventricular area, were quantified with computer-generated unfolded map method of the myocardial radioactivity. Despite no significant difference in peak plasma creatine phosphokinase between the two groups, patients with anterior myocardial infarction (28 patients) had larger %fixed defect (p < 0.01), which was associated with higher end-diastolic pressure (p < 0.05) and larger end-diastolic volume index (p < 0.01) than those with inferior myocardial infarction (19 patients). End-diastolic volume index was not related to %redistribution and %reverse redistribution, but there was a good relation between end-diastolic volume index and %fixed defect in anterior (r = 0.79, p < 0.001) and in inferior (r = 0.73, p < 0.001) myocardial infarction. However, left ventricular end-diastolic volume index in anterior myocardial infarction was larger than that of inferior myocardial infarction at any given %fixed defect. Thus, site as well as size of fixed defect at 2 weeks after the onset of acute myocardial infarction was related to left ventricular end-diastolic volume at chronic phase.

Angioplasty, Balloon, Coronary↗
PubMed1999

Enhancing effect of dietary vinegar on the intestinal absorption of calcium in ovariectomized rats.

We studied the effect of dietary vinegar on calcium absorption by using ovariectomized rats fed on a low-calcium diet. The apparent absorption of calcium was higher when the rats were fed on a diet containing 1.6% vinegar for 32 days than when fed on a diet without vinegar (P < 0.05). The calcium content in the femur of the rats given diets containing 0.4% and 1.6% vinegar were also higher (P < 0.05). The serum parathyroid hormone level was lower and the crypt depth of the duodenum thicker in the rats fed on a diet containing 1.6% vinegar (P < 0.05). These results suggest that dietary vinegar enhanced intestinal calcium absorption by improving calcium solubility and by the trophic effect of the acetic acid contained in vinegar, which would reduce the bone turnover caused by ovariectomy and be helpful in preventing osteoporosis.

Acetic Acid↗
PubMed1999

An investigation of the relationship between duct system and A cell-rich and PP cell-rich pancreatic islets in the canine pancreas.

The pancreata of four six-month-old dogs of the same mother, two with both the pancreatic and accessory pancreatic ducts (X-type) and two with only the accessory pancreatic duct (Y-type), were examined in this study. To clarify the relationships between the type of pancreatic duct system and the composition of pancreatic endocrine cells, the pancreata were examined immunohistochemically using antiserum against four types of pancreatic hormones (glucagon, insulin, somatostatin and pancreatic polypeptide). In all areas of the X- and Y-type duct system pancreata, B cells accounted for 52-82% of the total number of islet cells, and D cells accounted for 4-15%. In the X-type ducts system, the percentages of A and PP cells in the right and left lobes of the pancreas differed greatly. It was found that A and PP cells appear in inverse proportion to each other and that there exist A cell-rich and PP cell-rich pancreatic islets. The A cell-rich pancreatic islets appeared in the left lobes along the accessory pancreatic duct, while the PP cell-rich pancreatic islets were observed in the right lobes along the pancreatic duct. The body of the pancreas contained both A cell-rich and PP cell-rich pancreatic islets. In the Y-type duct systems, A cell-rich pancreatic islets appeared in the right lobes. These findings indicate that the composition of A and PP cells in pancreatic islets is closely related to the type of duct system.

Animals↗
PubMed1998

Pericardial effusion after primary percutaneous transluminal coronary angioplasty in first Q-wave acute myocardial infarction.

To evaluate the incidence and clinical significance of infarction-associated pericardial effusion in patients with successful primary percutaneous transluminal coronary angioplasty, we studied 214 consecutive patients with a first Q-wave acute myocardial infarction. Based on 9 clinical variables, multivariate analysis was performed to determine the important variables related to the occurrence of pericardial effusion. Pericardial effusion was detected by echocardiography in 45 patients (21%); pericardial rub (p <0.001), number of advanced asynergic segments (p <0.001), ventricular aneurysmal motion (p = 0.03), and pulmonary capillary wedge pressure (p = 0.04) were found to be the important variables related to pericardial effusion. Among 45 patients with pericardial effusion, 29 patients with no pericardial rub had significantly higher pulmonary capillary wedge pressure than those with pericardial rub, whereas 16 patients with pericardial rub had a higher incidence of angiographic no reflow and ventricular aneurysmal motion than those without pericardial rub. Patients with pericardial effusion and a pericardial rub had a higher mortality rate than those without pericardial effusion (19% vs 3%; p = 0.02). Thus, pericardial effusion is still a relatively common clinical finding after primary percutaneous transluminal coronary angioplasty, and those with pericardial effusion and a pericardial rub were associated with more severe transmural myocardial damage and higher in-hospital mortality.

Aged↗
PubMed1998

The role of infarction-associated pericarditis on the occurrence of atrial fibrillation.

AIMS: Transient atrial fibrillation is a relatively common arrhythmia in the early phase of acute Q-wave myocardial infarction. However, the role of infarction-associated pericarditis on the genesis of atrial fibrillation is controversial. This study was designed to examine the relative importance of infarction-associated pericarditis among other clinical variables on the genesis of transient atrial fibrillation in patients with acute myocardial infarction. METHODS AND RESULTS: Three hundred and ninety-eight patients with acute Q-wave myocardial infarction were examined carefully by means of auscultation, ECG, two-dimensional echocardiography and haemodynamic measurements. The diagnosis of pericarditis was made on the basis of pericardial rub detected during the first 3 days after admission. At least 0.5 mm of PQ-segment depression from a TP segment lasting more than 24 h in both limb and precordial leads was considered diagnostic of PQ-segment depression. Atrial fibrillation was present in 76 patients (19%). Sixteen (42%) of 38 patients with PQ-segment depression had atrial fibrillation, whereas 23 (30%) of 77 patients with pericardial rub had atrial fibrillation. Based on ten clinical variables, multivariate analysis was performed to determine the important variables related to the occurrence of atrial fibrillation. PQ-segment depression (chi-square = 4.10, P < 0.05) was selected with age (chi-square = 10.52, P < 0.005), the number of left ventricular segments with advanced asynergy (chi-square = 7.73, P < 0.01) and pericardial effusion (chi-square = 7.95, P < 0.005) as important factors related to atrial fibrillation. Patients with PQ-segment depression had a significantly higher pulmonary capillary wedge pressure than those without it. CONCLUSION: Among patients with infarction-associated pericarditis, those with PQ-segment depression represent atrial involvement associated with extensive myocardial damage and hence, PQ-segment depression is one of the clinical signs related to the occurrence of atrial fibrillation in acute Q-wave myocardial infarction.

Aged↗
PubMed1998

Fine structural and histochemical study of equine Paneth cells.

Ultrastructure, lysozyme and glycoconjugate activity in duodenal Paneth cells were observed concurrently in the horse. Paneth cells were seen to uniformly line the base of the equine intestinal glands. The round secretory granules have centrally located electron densities with peripherally located electron lucent halos. Histochemically, the peripheral halo layer was positively stained for carbohydrates by the periodic acid-thiocarbohydrazide-silver protein-physical development (PA-TCH-SP-PD) method and the entire granules reacted positively to the WGA. The central core area reacted with anti-lysozyme. We identified a young (Type I) and an old (Type II) cell population in the same crypt, but we suggest that the observed populations are variations of the same cell type with the varied appearance due to aging of the secretory granules.

Animals↗
PubMed1998

Diastolic time during weight carrying exercise in patients with myocardial infarction.

Cardiovascular responses to static-dynamic exercises were studied in 27 patients with recent myocardial infarction. Patients with ischemic electrocardiographic changes at peak weight carrying exercise (group 1 = 8 patients) had a significantly larger left ventricular end-diastolic volume than those without (group 2 = 19 patients). A higher tension time index and shortening of diastolic time/min was observed in group 1 compared to group 2 during weight carrying. Thus, in addition to the increased myocardial oxygen demand, shortening of the diastolic perfusion time was observed during static-dynamic exercise in patients with dilated heart after myocardial infarction.

Diastole↗
PubMed1997

Resolution of late potentials with improvement in left ventricular systolic function in patients with first acute myocardial infarction.

BACKGROUND: Ventricular late potentials predict subsequent arrhythmic events and sudden death in postinfarction patients. Late potentials are recorded in the infarcted area, but it should be pointed out that they probably represent micropotentials in the area of delayed conduction found among isolated areas of scar tissue and normal myocardium. HYPOTHESIS: The study was undertaken to investigate the relationship between chronic reversible myocardial ischemia, such as stunned or hibernating myocardium, and late potentials in 38 patients with a first myocardial infarction. METHODS: The patients were divided into two groups, one with (Group 1) and one without (Group 2) resolution of late potentials recorded by signal-averaged electrocardiogram at 6 months after onset of myocardial infarction. We investigated the clinical, echocardiographic, and signal-averaged electrocardiographic characteristics of Groups 1 and 2. RESULTS: In the chronic phase of myocardial infarction, a higher incidence of patency of the infarct-related artery and an improvement of wall motion score were found in Group 1, and left ventricular ejection fraction was better preserved in Group 1 than in Group 2. CONCLUSIONS: These results suggest that the resolution of late potentials was influenced by the improvement of left ventricular systolic function and patency of the infarct-related artery. We concluded that chronic reversible myocardial ischemia, such as stunned or hibernating myocardium, might be the substrate that generated late potentials.

Action Potentials↗
PubMed1997

Importance of left ventricular diastolic function on maintenance of exercise capacity in patients with systolic dysfunction after anterior myocardial infarction.

To investigate the role of left ventricular (LV) diastolic function in the maintenance of exercise capacity in patients with systolic dysfunction, symptom-limited cardiopulmonary exercise testing combined with radionuclide ventriculography was performed in 24 patients with an LV ejection fraction < 35% after anterior myocardial infarction. The ratio of pulmonary artery wedge pressure (PAWP) to LV end-diastolic volume (EDV), an index of global diastolic function, correlated significantly with peak oxygen consumption at peak exercise (r = -0.55; p = 0.006), whereas ejection fraction at peak exercise did not. The change in PAWP/EDV ratio from rest to peak exercise was related to the increases in stroke volume (r = -0.54; p = 0.006) and cardiac output (r = -0.51; p = 0.01) during exercise, but the change in ejection fraction was not. Resting hemodynamics did not differ between patients with preserved exercise capacity (group 1, n = 8) and those with exercise impairment (group 2, n = 16). At peak exercise, stroke volume, cardiac output, and EDV were significantly higher, and PAWP and PAWP/EDV ratio were significantly lower in group 1 than in group 2, but ejection fraction and end-systolic volume were similar in both groups. Although the incidences of hypertension, LV hypertrophy, and infarct-related coronary artery lesions did not differ between the two groups, group 2 had a significantly higher incidence of non-infarct-related coronary artery lesions than group 1 (p < 0.05). Thus in patients with LV systolic dysfunction after anterior myocardial infarction, the major cause of exercise impairment and failure to increase LV performance during exercise was diastolic dysfunction associated with the presence of non-infarct-related coronary artery lesions with the potential for exercise-induced ischemia of the noninfarcted areas.

Adult↗
PubMed1997

Morphological study of bovine pregnant corpus luteum cells.

The bovine pregnant corpus luteum was examined morphologically, to clarify the appearance and properties of the intramitochondrial bodies (IMB) in mitochondria of the large luteum cell (LLC). The incidence and diameter of the IMB (200-900 nm) showed a tendency to increase with the advance of pregnancy. Histochemically, the IMB reacted positively with protein, and immunohistochemically, they reacted IMB with 11 alpha-hydroxyprogesterone-1-11 succinyl-bovine serum albumin (P-BSA). The IMB seemed to combine with protein, and these granules did not undergo exocytosis. The cytoplasm of LLC contained another type of small electron-dense granules that were 150-200 nm in diameter, had an orifice for secretion, and reacted with relaxin. Small luteum cells (SLC) revealed crystalline-like inclusions. It is suggested that these inclusion cells participate in the synthesis of steroids.

Animals↗
PubMed1997

Prognostic significance of precordial ST-segment changes in acute inferior wall myocardial infarction.

STUDY OBJECTIVE: To examine the clinical significance of precordial ST-segment changes in patients with acute Q-wave inferior wall myocardial infarction. DESIGN: Prospective evaluation (clinical follow-up) of Q-wave inferior wall myocardial infarction over a 6-year period in patients who fulfilled the inclusion criteria. SETTING: Coronary care unit at a university hospital. PATIENTS: Two hundred consecutive patients with acute Q-wave inferior wall myocardial infarction admitted to the coronary care unit within 24 h from the onset of chest pain. MEASUREMENTS AND RESULTS: Precordial ST-segment depression resolved <24 h (transient) after admission in 84 patients, lasted > or = 24 h (persistent) in 48 patients, and was absent in 68 patients, while ST-segment elevation in V4R was detected in 60 patients. Seventy-one patients had major in-hospital complications and 18 patients died in the hospital. When nine variables were used in the multivariate analysis, right ventricular dilatation and persistent precordial ST-segment depression were the important factors related to major in-hospital complications, whereas age, alveolar arterial oxygen difference, and persistent precordial ST-segment depression were important for in-hospital deaths. CONCLUSION: Left ventricular posterior wall involvement, diagnosed by persistent precordial ST-depression, was an independent and stronger predictor of major in-hospital complications and deaths than right ventricular involvement in patients with acute Q-wave inferior wall myocardial infarction.

Adult↗
PubMed1997

Serial assessment of sympathetic reinnervation in a patient with myocardial infarction.

Resting [123I]MIBG and 201TI imaging were performed at 2 wk and 4 and 12 mo after successfully reperfused myocardial infarction. Although [123I]MIBG uptake of the infarcted segments revealed significant improvement in the early image at 4 mo, delayed image displayed decreased [123I]MIBG uptake. However, decreased [123I]MIBG uptake of the delayed image became almost uniform at 12 mo. These observations suggest that reinnervation initially occurs in norepinephrine uptake and then in retention ability. On the other hand, a 201TI defect remained in the infarcted segments at 12 mo. Thus, reinnervation can occur not only in the peri-infarct area but also in the infarcted area.

3-Iodobenzylguanidine↗
PubMed1996

Diastolic time during exercise-induced myocardial ischemia in patients with myocardial infarction.

The relation between diastolic time and myocardial perfusion defect redistribution of the infarct-related region was studied during upright bicycle exercise with thallium-201 scintigraphy in 37 patients with recent anterior myocardial infarction. In addition to the higher incidence of residual stenosis of the infarct-related artery, a disproportionate shortening of diastolic time in patients with myocardial perfusion defect redistribution permitted further reduction of subendocardial blood flow during exercise.

Diastole↗
PubMed1996

Tumor cell autocrine motility factor is the neuroleukin/phosphohexose isomerase polypeptide.

To date, the structure of the autocrine motility factor (AMF), a tumor-secreted cytokine which stimulates cell migration in vitro and metastasis in vivo, is unknown. Here, AMF secreted by Gc-4 PF murine fibrosarcoma into a protein-free conditioned media was isolated, purified, and microsequenced. The results demonstrate that AMF is the previously cloned cytokine and enzyme designated as neuroleukin, and phosphohexose isomerase (PHI), which has been independently implicated in cell motility, and to be a cancer progression marker. PHI catalyzes isomerization of glucose 6-phosphate to fructose 6-phosphate and is specific for both sugars. Murine AMF exhibits the enzymatic properties of PHI and rabbit heart PHI-stimulated mouse fibrosarcoma cells' motility similar to those of the endogenous AMF. Specific PHI inhibitors (carbohydrate phosphates) inhibited enzymatic activity and AMF-induced cell motility.

Amino Acid Sequence↗
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↗