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Biomedical subjects

K Takehana

Publications and source records attributed to K Takehana.

At least 73 records · Page 4Linked to original sources
PubMed1993

Disturbance of pulmonary gas exchange in patients with acute myocardial infarction-associated pericardial effusion.

To elucidate the effect of pericardial effusion on pulmonary gas exchange in patients with infarction-associated pericardial effusion, 294 consecutive patients with their first Q-wave anterior wall acute myocardial infarction were examined carefully by echocardiography, chest radiography and hemodynamic monitoring. A pericardial effusion was detected in 77 patients and was absent in 217 (group 1). Of the 77 patients with pericardial effusion, it was mild in 57 (group 2) and moderate in 20 (group 3). Patients with pericardial effusion (groups 2 and 3) had significantly greater pulmonary artery wedge pressure and more left ventricular segments with advanced asynergy than did those in group 1. Although there were no significant differences in pulmonary artery wedge pressure and number of left ventricular segments with advanced asynergy between groups 2 and 3, group 3 had significantly greater right atrial pressure, alveolar arterial oxygen difference and incidence of high radiographic score. Thus, accumulation of pericardial effusion to a moderate amount may contribute to the greater incidence of increase in extravascular lung water, and disturbance of pulmonary gas exchange.

Aged↗
PubMed1993

Precordial ST segment depression in patients with Q wave inferior myocardial infarction: role of infarction-associated pericarditis.

To examine the diagnostic significance of precordial ST segment depression in Q wave inferior myocardial infarction, 157 consecutive patients were examined carefully by means of auscultation, ECG, and two-dimensional echocardiography. Precordial ST segment depression was transient (lasting < 72 hours from the onset of myocardial infarction) in 63 patients and persistent (> or = 72 hours) in 40. Twenty-eight patients with persistent, 19 patients with transient, and 14 patients without precordial ST segment depression had advanced asynergy (akinesia or dyskinesia) in the posterior segments, whereas 13 patients with persistent, six with transient, and six without precordial ST segment depression had pericardial rub. Patients with persistent precordial ST segment depression had a significantly higher incidence of severe wall motion abnormality (p < 0.01) and inflammation (p < 0.05) of the posterior wall than the other two groups. In 5 of 40 patients with persistent ST segment depression, pericardial rub was detected in the absence of advanced asynergy in the posterior segments. Although not highly sensitive, persistent precordial ST segment depression appeared to be a fairly specific indicator (specificity 92%) of concomitant posterior involvement with severe wall motion abnormality, inflammation, or both.

Aged↗
PubMed1993

Effect of sex on left ventricular pump function in patients with anterior wall myocardial infarction treated with primary angioplasty.

BACKGROUND: The prognosis of acute myocardial infarction (AMI) is distinctly worse in postmenopausal women than in age-matched men. Unstable angina before AMI is reported to protect left ventricular pump function during the left ventricular remodeling process in patients who have undergone successful percutaneous transluminal coronary angioplasty (PTCA). We postulate that left ventricular pump function may be different in postmenopausal women and age-matched men with unstable angina before AMI and successful PTCA. METHODS: Twenty-three postmenopausal women (aged 63 +/- 7 years) and 31 age-matched men (aged 65 +/- 6 years) with unstable angina before AMI and successful PTCA were investigated using radionuclide angiography in the late hospital phase. RESULTS: Global ejection fraction (EF), regional EF of the non-infarcted area, and the ratio of systemic arterial systolic blood pressure to left ventricular end-systolic volume (P:V ratio) were lower in women compared with those in men. Global EF, regional EF of the non-infarcted area, and the P:V ratio in women with left ventricular end-diastolic volume (EDV) > or = 140 ml were significantly lower than in those with a left ventricular EDV of less than 140 ml, but no significant differences were noted in these indexes with regard to left ventricular EDV in men. CONCLUSION: Sex may play an important role in the left ventricular remodeling process in postmenopausal women, especially those with a dilated left ventricle.

Aged↗
PubMed1993

Increase in left ventricular ejection rate during recovery from exercise in patients with myocardial infarction.

Changes in left ventricular (LV) ejection rate were evaluated during supine bicycle exercise and recovery in 12 patients with anterior myocardial infarction. Pulmonary artery wedge pressure (34 +/- 9 to 14 +/- 5 mm Hg) and plasma norepinephrine level decreased at 2 min recovery from peak exercise, whereas plasma lactate tended to increase. As a result, LV ejection rate reached the highest value at 2 min of recovery. Thus, both cardiac (optimal filling pressure) and peripheral factors (reduced vascular resistance) caused the increase in LV ejection rate at early recovery.

Acid-Base Equilibrium↗
PubMed1993

Cervico-pectoral ectopia cordis in two Holstein calves.

Two Holstein calves affected with cervico-pectoral ectopia cordis, a male (No. 1) delivered stillborn and a female (No. 2) died 1 hour after birth, were examined macroscopically and radiographically to assess the severity and elucidate the teratogenesis of the anomaly. The heart of one calf was covered by the intact pericardium and skin and displaced to the caudalmost portion of the ventrocervical region, just cranial to an enlarged thoracic inlet. The cranial vena cava and the vena azygos were duplicated. The sternum was bilaterally divided into two parts fused only at the xyphoid process and was semicircular. The heart of the other calf, covered solely by the pericardium, was exposed ventrally from an oval opening in the body wall just cranial to a defective Y-shaped sternum. In both calves, the arterial branching pattern from the aortic arch was intermediate between the patterns of the dog and pig, and in each case a single pulmonary vein emptied into the left atrium. Pronounced or slight torticollis, cleft palate, and abnormalities in the urogenital system were also found. From an embryological perspective, cervical and pectoral ectopia cordis have a common pathogenesis; the cervical type occurs at a slightly earlier fetal stage than the pectoral type.

Animals↗
PubMed1993

Electron microscopic studies on reticular fibers in the pig sheathed artery and splenic cords.

The reticular fibers of the capillary sheath and splenic cord were studied in the pig spleen by transmission electron microscopy to reveal their components and the presence of sialic acid in the amorphous ground substance. Collagen fibrils, elastic fibers, microfibrils, nerve fibers and smooth muscle cells were observed in the reticular fibers of the splenic cord, while only microfibrils were recognized in the reticular fibers of the capillary sheath. The binding of LFA lectin to the splenic cord was stronger than the capillary sheath. These findings may suggest that the reticular fibers of the splenic cord include numerous functional elements and perform an important role during contraction or dilation of the spleen. On the other hand, it seems to be reasonable to term the capillary sheath as "capillary basement membranous reticular tissue", since the reticular fiber of the capillary sheath resembles the basement membrane of the capillary in its components.

Animals↗
PubMed1993

Three-dimensional reconstruction of the pig sheathed artery.

The structure of the sheathed artery and the number of branches of the sheathed capillary were investigated by three-dimensional reconstruction computer graphics in the pig spleen. The capillary branched 1 to 6 times in the capillary sheath in more than 90% of all samples examined. The sheathed artery varied in shape and size in accordance with the number of branches and direction of the capillary. The usual descriptions for the sheathed artery were suggested to be mostly in appropriate at least for that of the pig spleen.

Animals↗
PubMed1993

Effect of infarct site on diastolic time during exercise.

To assess the difference in left ventricular performance during exercise between anterior (11 patients) and inferior (10 patients) myocardial infarction (MI) of equivalent size, patients performed a supine bicycle exercise 6 to 8 weeks after the first acute MI. All patients had negative exercise test results and despite no significant differences in HR, blood pressure and stroke volume index at peak exercise, pulmonary artery wedge pressure was significantly higher in anterior (35 +/- 7 mm Hg) than in inferior MI (27 +/- 9 mm Hg). Although there were no significant differences in electromechanical systole (QS2) and diastolic time (DT) at rest, a significant prolongation of QS2 with consequent shortening of DT (p < 0.01) was observed at peak exercise in anterior MI. In addition to decreased subendocardial coronary blood flow from increased left ventricular end-diastolic pressure, a disproportionate shortening of DT in anterior MI may initiate subendocardial ischemia in the noninfarcted segments, which may further impede subendocardial blood flow.

Blood Pressure↗
PubMed1993

Clinical significance of pericardial effusion associated with pericarditis in acute Q-wave anterior myocardial infarction.

To elucidate the incidence and clinical factors related to the occurrence of pericardial effusion in infarction-associated pericarditis, 303 consecutive patients with their first Q-wave anterior myocardial infarction were examined carefully by means of auscultation, echocardiography, chest radiography, and hemodynamic monitoring. During the first 3 days, a pericardial rub was detected in 65 patients and was absent in 238 patients. Among the 65 patients with pericardial rub, pericardial effusion was present in 27 patients (group 1) and was absent in 38 patients (group 2). Although there were no significant differences in cardiac output, pulmonary artery wedge pressure and right atrial pressure between the two groups, patients in group 1 had significantly more left ventricular segments with advanced asynergy and higher radiographic scores (diffuse interstitial infiltrate or alveolar infiltrate) compared with those in group 2. Thus, pericardial effusion and increased extravascular lung water in infarction-associated pericarditis were not caused by left ventricular failure but by other mechanisms reflecting a larger infarct.

Electrocardiography↗
PubMed1993

Three-dimensional structure of dog Sertoli cells: a computer-aided reconstruction from serial semi-thin sections.

The three-dimensional structure of the Sertoli cell in the Korean Jindo dog was investigated by scanning and transmission electron microscopy. Additionally, type-A and type-B Sertoli cells were simulated by three-dimensional computer graphic imaging to clarify the anatomical relationship between Sertoli cell and germ cells. Descriptions in the present study are based on examination of the reconstructed type-A cells at stages IV, V and VI of the spermiogenetic cycle and stages VII, VIII and IX of the reconstructed type-B Sertoli cells. Morphologically, three types of Sertoli cell processes were evident: 1) flat club-like, elliptical processes bifurcating and trifurcating randomly; 2) slender cord-like, tubular processes; and 3) sheet-like processes. The sheet-like processes rested upon more than half the surface of each round spermatid located in the proximity of the Sertoli cell. Curiously, just before spermiation, the apical club-like processes shifted from their initial position at the spermatid head and subsequently covered the disengaged residual body, after which the residual body was no longer evident in the tubule. Though the mechanism for this elimination is not known, the process suggests a reciprocity between the Sertoli and germ cells. An anatomical dissimilarity between type-A and type-B Sertoli cells appeared in the apical region, with the apical club-like processes of the type-B Sertoli cell given off by sheet-like processes as well as by the Sertoli column. At the base of all Sertoli cells, sophisticated sheet-like processes paralleled the basal lamina, tenaciously adhering end-to-end to the sheet-like processes of adjacent Sertoli cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Histochemistry of glandular metaplasia at the trigone of the urinary bladder in cows.

The epithelium at the trigone of the urinary bladder showed intestinal metaplasia of a colonic type in three Holstein-Friesian cows affected with chronic polypoid cystitis. Except for Ricinus communis (RCA-I), almost all goblet cells in the whole crypt were positive to periodic acid-Schiff (PAS), alcian blue (AB) pH 2.5, AB pH 1.0, periodate borohydride-potassium hydroxide-PAS (PB-KOH-PAS), Ulex europaeus (UEA-I), Triticum vulgare (WGA) and Arachis hypogaea (PNA) after neuraminidase digestion. This result indicated that most goblet cells contained acidic and neutral glycoconjugates as O-acetylated sialomucin, L-fucose, N-acetyl-glucosamine, neuraminic acid residues and sialic acid-galactose dimers and were devoid of beta-D-galactose. The goblet cells at the surface in the upper half of the crypt contained both sulpho- and sialo-mucins with N-acetyl-galactosamine residues by AB (pH 2.5)-PAS, high iron diamine (HID)-AB (pH 2.5), Dolichos biflorus (DBA) and Glycine maximus (SBA) reactions. On the other hand, the lower goblet cells were found to contain predominantly sulphated mucins with D-mannose and D-glucose residues by AB-PAS, HID-AB and Concanavalia ensiformis (Con A) reactivities. This suggested that mucin secreted from these cells was similar to that secreted from the goblet cells of the large intestine in cattle.

Alcian Blue↗
PubMed1992

Cytoplasmic filaments in the endothelial cells of the sheathed capillary: an ultrastructural and immunocytochemical study in the pig spleen.

Cytoplasmic filaments of the endothelial cells of sheathed capillaries in the pig spleen were identified and their ultrastructure was studied. Two types of cytoplasmic filaments were found: intermediate filaments (diameter: 10 nm) which filled most of the interior of the cells, and thin filaments (diameter: 5 nm) which were located just beneath the cell membrane and filled the lateral cytoplasmic processes. In immunocytochemical preparations, the intermediate filaments were positive for vimentin and desmin, and were negative for keratin. Staining of the thin filaments with heavy meromyosin resulted in arrowhead formations. These observations suggest that the intermediate filaments maintain the cytoarchitecture, possibly protecting the cell from structural alterations induced by blood pressure changes. Concurrently, thin filaments may facilitate the passage of red blood cells and blood platelets through the interendothelial fenestrae of the sheathed endothelial cell to the reticular meshwork in the capillary sheath.

Animals↗
PubMed1992

Diastolic time and left ventricular performance during one- and two-handed weight holding.

To evaluate the difference in DT and systolic time intervals during one-handed and two-handed weight holding with the same total load, the DT-heart rate relationship was studied in 12 patients and ten normal volunteers. Heart rate, blood pressure, and pressure-rate product were significantly higher in one-handed compared with two-handed weight-holding exercise in patients with MI. Although there were no significant differences in QS2 and DT between the two types of weight-holding exercise in normal volunteers, QS2 was significantly longer and DT was significantly shorter in one-handed compared with two-handed weight-holding exercise in patients with MI. Disproportionate shortening of DT with higher pressure-rate product during one-handed compared with two-handed weight-holding exercise can initiate an imbalance of myocardial oxygen supply and demand in patients with MI.

Analysis of Variance↗
PubMed1991

Interaction of nuclear factors with the regulatory region of the N-myc gene during differentiation of human embryonal carcinoma cells.

The human embryonal carcinoma cell line, NEC14, can be induced to differentiate by the addition of 10(-2) M N,N'-hexamethylene-bis-acetamide (HMBA). During the early stage of HMBA-induced differentiation, the level of N-myc expression decreased steeply and transiently, and then quickly returned to its original level after reaching a minimal level at 18 h after addition of HMBA. Nuclear run-on experiments indicated that this transient decrease is regulated at the transcription start point. To investigate the mechanism of this down-regulation, the 5'-flanking region of the human N-myc gene was cloned and sequenced. Computer analysis of the sequence revealed high homology with the 5'-flanking region of the mouse N-myc gene, especially (greater than 80%) in the region of nt positions -1777 to -1732, nt positions -763 to -501 and nt positions -260 to + 1. The patterns of protein binding to the upstream region during the early stage of NEC14 cell differentiation were analyzed by gel retardation assay. The DNA fragments VIII and X, containing the sequences of nt positions -1437 to -1237 and nt positions -1863 to -1710, respectively, formed the DNA-protein complexes which were greatly reduced in quantity in the cell extract prepared 18 h after the addition of HMBA. This reduction, however, was not observed with an extract similarly prepared from the NEC14 derivative cell line, H10, expressing the N-myc gene constitutively. These results suggest a causal connection between the complex formation and the high-level transcription of the N-myc gene.

Acetamides↗
PubMed1991

A transient decrease in N-myc expression and its biological role during differentiation of human embryonal carcinoma cells.

The human embryonal carcinoma (EC) cell line, NEC14 can be induced to morphologically differentiate by the addition of 10(-2) M N,N'-hexamethylene-bis-acetamide (HMBA) in vitro. The expression of several cellular oncogenes (c-onc) in NEC14 cells was examined after induction of differentiation by HMBA. The level of N-myc expression was the highest in undifferentiated cells but decreased transiently to less than 1/10 of the original level shortly after the induction of differentiation. To investigate the role of the transient decrease in N-myc level on NEC14 cell differentiation, a chimeric human N-myc gene in which transcription is initiated at the human beta-actin gene promoter was constructed and introduced into NEC14 cells. Several transformants expressing the exogenous N-myc gene constitutively were established. These transformants showed 10- to 70-fold increases in plating efficiency and shorter population doubling times as compared with the parental NEC14 cells. The transformants were hard to induce, spontaneously differentiated cells on the periphery of cell clusters in culture, unlike parental NEC14 cells, and took longer for HMBA-induced morphological differentiation. The populations of the cells expressing HLA and SSEA-1 antigens increased from 10%-20% to nearly 100% in NEC14 cells after the induction of differentiation, while the populations expressing these antigens increased only to 50%-60% in one of the transformants, S11. The transformants gained an increased tumorigenic potential in nude mice, and the tumors produced consisted exclusively of EC stem cells. These results suggest that the additional expression of the exogenous N-myc gene (increased about two-fold) confers the more transformed state on the cells.

Antigens, Surface↗
PubMed1991

Duodenal glands of the pony (Equus caballus).

The ultrastructure and histochemistry of the duodenal glands of the pony (Equus caballus) was examined in four horses. Unlike that of most species except for the rabbit, the submucous glands of the horse contain two distinct cell types, serous and mucous. These cells are described.

Animals↗
PubMed1991

Ultrastructure of the red pulp in spleen innervation in horse and pig.

The innervation of the red pulp in the spleen of horse and pig was investigated by electron microscopy. In addition, the neurilemma was studied by immunohistochemistry specific for S-100 protein. In the pig, a large population of smooth-muscle cells extending from the smooth-muscle trabeculae was present in the red pulp. The cytoplasmic processes of reticular cells enwrapped the smooth-muscle cells, and nerve fibres were distributed between the smooth-muscle cells and the reticular cells. The nerve terminals clustered toward the facing of the smooth-muscle cells. Nerve fibres and terminals were not disclosed within the sheathed artery. Immunohistochemically the neurilemma showed a reaction positive for S-100 protein. In the horse, no smooth-muscle cells were noted in the red pulp. The nerve fibres terminated around the cytoplasmic processes of the reticular cells. Nerve fibres and terminals were disclosed within the sheathed artery, and the terminals contained both large and small dense-cored vesicles. Immunohistochemically the neurilemma showed a reaction negative for S-100 protein. These findings support the presence of the axon-bearing reticular cells described earlier in the horse spleen.

Animals↗