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Biomedical subjects

K Taniguchi

Publications and source records attributed to K Taniguchi.

At least 19 recordsLinked to original sources

Differences between vasorelaxant responses of the canine and human mesenteric arteries and veins to amrinone.

Amrinone induced similar degrees of relaxation in human mesenteric arteries and veins contracted with KCl, but exerted a more potent vasodilator effect in canine mesenteric veins than in arteries. Dibutyryl cAMP had a stronger effect on KCl-induced contraction in canine mesenteric veins than in arteries. These results suggest that amrinone promotes a different vasodilating action in human and canine mesenteric vessels, possibly via different sensitivity to cAMP in each vascular smooth muscle.

Amrinone

Antiinflammatory and analgesic activity of a non-peptide substance P receptor antagonist.

CP-96,345, a potent non-peptide antagonist of the substance P (SP) receptor, inhibited SP-, neurokinin A (NKA)- and neurokinin B-induced plasma extravasation in guinea pig dorsal skin. The inhibition was specific for the three tachykinins; CP-96,345 was not active against plasma leakage caused by histamine, bradykinin, platelet-activating factor or leukotriene D4. CP-96,345 inhibited capsaicin-induced plasma extravasation in the ureter, an inflammatory response caused by neuropeptides released from afferent C-fibers. Thus, the NK1 receptor appears to play a major role in vascular permeability increases induced by exogenous and endogenous tachykinins. In contrast, CP-96,345 was inactive against SP- and NKA-induced contraction of guinea pig ureter, suggesting that the smooth muscle contraction is not NK1-mediated. CP-96,345 exhibited analgesic activity in acetic acid-induced abdominal stretching in mice, indicating for the first time that SP plays a critical role in this model. The results of these studies support a pathophysiological role of SP and NK1 receptor under acute neurogenic inflammatory conditions and in pain.

Analgesics

[Thinning of ventricular septum in tetralogy of Fallot].

Cross sectional echocardiography was used to evaluate the thickness of the ventricular septum in tetralogy of Fallot (TOF). Forty-six patients with TOF and 20 patients with pseudo-truncus arteriosus underwent echocardiography during a five-year period beginning in 1984. Thicknesses of the right ventricular anterior wall (RVAWT), trabecular septum (IVST) and left ventricular posterior wall (LVPWT) were measured in end diastole on parasternal short axis view at the level of the tips of papillary muscles. The ratios of IVST to RVAWT and IVST to LVPWT were assessed. The ratio of IVST to RVAWT was 1.09 +/- 0.15 in the group aged less than 7 years (less than 7 y.o.) and 0.94 +/- 0.15 in the group aged of 7 years or more (greater than = 7 y.o.). The ratios of IVST to LVPWT were 1.10 +/- 0.14 (less than 7 y.o.) and 0.90 +/- 0.15 (greater than = 7 y.o.), respectively. Both ratios were significantly different (p less than 0.01) in the two age groups, and relative thinning of the septum was demonstrated in the older patients. It is speculated that thinning of the interventricular septum is caused by the lower systolic wall stress of the ventricular septum compared with that of the free walls, which is produced under equal systolic pressure of the two ventricles. It is suggested that this thinning is one of the factors that reduces left ventricular function after repair of TOF.

Adolescent

A partial defect in technetium-99m pyrophosphate image suggesting cardiac rupture following acute myocardial infarction.

We present the case of a 70-year-old woman with acute myocardial infarction who died of cardiac rupture on the 2nd hospital day. Dual isotope single photon emission computed tomography (SPECT) using thallium-201 chloride and technetium-99m pyrophosphate (PYP) performed on the 2nd hospital day showed a large perfusion defect in the anteroseptal wall on 201Tl image and a increased accumulation on 99mTc-PYP image in the anterior area consistent with a partial defect. Autopsy performed 1 h after death revealed a tear in the left ventricular anterior wall consistent with the defect on the 99mTc-PYP image. We propose that the finding of a partial defect in 99mTc-PYP is an interesting finding which may be associated with cardiac rupture following acute myocardial infarction.

Aged

Coronary bypass using arterial grafts in homozygous familial hypercholesterolemia.

A 25-year-old man with homozygous familial hypercholesterolemia who had severe coronary artery disease underwent coronary revascularization by combined arterial grafts using bilateral internal mammary arteries and gastroepiploic artery. Early postoperative coronary angiography showed all the grafts patent without any stenosis. Because no atherosclerotic changes were seen in the specimens of each graft used, combined arterial grafting may have a role in the treatment of coronary artery disease in homozygous familial hypercholesterolemia.

Adult

Transaortic patch angioplasty for left coronary ostial stenosis in a patient with Takayasu's aortitis.

A 35-year-old woman who had left coronary ostial stenosis and aortic valve regurgitation due to Takayasu's aortitis underwent transaortic patch enlargement of the stenosed left coronary ostium in combination with aortic valve replacement. This technique may be suitable and recommendable as an alternative to aortocoronary bypass grafting or endarterectomy for coronary ostial stenosis in Takayasu's aortitis.

Adult

A study on optimal temperature for isolated lung preservation.

Fifty-two heart-lung blocks (grafts) of New Zealand white rabbits were used for determining optimal temperature in lung preservation. Grafts were inflated with room air and preserved by simple surface cooling at arbitrarily determined temperatures for 18 hours. Graft function was assessed by nonrecirculated perfusion with autologous blood. Segmented regression models between functional parameters and preservation temperature (T) were applied for determining optimal temperature. Graft ability was also assessed from the point of view of pulmonary circulation by indocyanine green dilution rate of effluent and histological distribution of carbon particles. Significant segmented regression curves and lines between parameters of effluent oxygen tension (PO2) and wet-dry weight ratio (W/D), and T were obtained as follows: PO2 = 150/(1 + 3208.1[e-1.17T]), p less than 0.01; PO2 = -13.8T + 222.6, p less than 0.05; W/D = 5.0 + 1.5/(1 + 0.0028[e0.94T]), p less than 0.01; W/D = 0.075T + 4.52, p less than 0.05. Optimal temperature for lung preservation by topical cooling was calculated as 8 degrees to 9 degrees C from each intersecting point of regression equations. Analysis of regression curves suggested that the most common hypothermic ischemic injury during preservation by topical cooling is pulmonary vascular obstruction, which might be induced at temperatures lower than the critical temperature of 6 degrees to 7 degrees C. Indocyanine green dilution rate and histological findings supported the results of graft functional parameters.

Animals

Anaerobic metabolism as an indicator of aerobic function during exercise in cardiac patients.

To determine whether patients with heart disease depend more than normal subjects on anaerobic metabolism to perform the same level of exercise, the anaerobic threshold, slope of the increase in carbon dioxide output with respect to oxygen uptake (delta VCO2/delta VO2) and the slope of the increase in oxygen uptake with respect to the increase in work rate (delta VO2/delta WR) both below and above the anaerobic threshold during exercise were evaluated. A total of 106 patients with chronic heart disease and 42 healthy subjects performed a symptom-limited incremental exercise test in a ramp pattern on a cycle ergometer. Peak oxygen uptake was significantly lower in the patients with heart disease than in the normal subjects. The anaerobic threshold, which was 20 +/- 4.6 ml/min per kg in normal subjects, decreased significantly with progressing severity of functional class: 16 +/- 2.4, 14.1 +/- 2.5 and 11.3 +/- 1.5 ml/min per kg, respectively, in patients in class I, class II and class III. The slope of delta VO2/delta WR, which represents the degree of aerobic metabolism, was also decreased both below and above the anaerobic threshold with increasing severity of heart disease. delta VCO2/delta VO2 below the anaerobic threshold was approximately 0.9 (p = NS between normal subjects and patients). However, delta VCO2/delta VO2 above the anaerobic threshold became steeper with increasing severity of heart disease: 1.37 +/- 0.17 in normal subjects versus 1.55 +/- 0.24, 1.67 +/- 0.3 and 1.8 +/- 0.35 respectively, in patients in functional class I, class II and class III.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerobiosis

An appraisal of patch enlargement of the small aortic annulus in 33 patients undergoing aortic valve replacement.

To avoid the problem of valve prosthesis/patient mismatch in the late postoperative period, we have adopted patch enlargement of the small aortic annulus in 33 patients having undergone aortic valve replacement since 1975, when the aortic annulus could not accept a large enough prosthesis. The mean age was 40 years, including 2 children aged 4. The technique of patch enlargement utilized was Nicks' method wherein the incision does not extend onto the mitral leaflet. In 31 adult patients, the aortic annulus before enlargement ranged in diameter from 18 to 24 mm with an average of 20.8 mm. After enlargement, the diameter of the annulus was 25.0 mm on average. In 2 children, the mean diameter of the annulus was enlarged from 16.5 mm to 20.5 mm. There were 2 early deaths in the initial series and 2 late deaths. Patch enlargement of the small aortic annulus is a simple, safe, and effective adjunct permitting the insertion of a valve one or two sizes larger than that which could be accommodated by the native annulus.

Adolescent

Cylindrical cell papilloma of the nasal cavity and paranasal sinuses. A histochemical and cytochemical study.

A cylindrical cell papilloma occurring in the sino-nasal mucosa of a 61-year-old woman was studied histochemically at both light and electron microscopic levels. The cylindrical cells demonstrated distended intracytoplasmic microcysts with numerous microvillous projections on the apical cell membrane. The retained mucosubstance in the cystic spaces stained intensely with HID-TCH-SP sequence and showed no apparent communication with the extracellular space. These findings indicate that the cylindrical cells may be of mucous-secreting cell derivation, being derived from cells possessing abnormal and/or failed secretory function. The property of sulfated mucin in the 'cylindric' intracytoplasmic cysts is suggested to be the result of endodermal displacement or metaplasia of the Schneiderian epithelium.

Female

Identification of human and bovine rotavirus serotypes by polymerase chain reaction.

The use of the polymerase chain reaction (PCR) for identifying serotypes of human and bovine rotaviruses was examined. In the identification of 115 human rotavirus samples in stools, results with PCR showed excellent agreement with results of serotyping by an enzyme-linked immunosorbent assay (ELISA) using serotype-specific monoclonal antibodies. Furthermore, the PCR showed a much higher sensitivity (93%) than the ELISA test (82.6%). The PCR method could also be applied for identifying the serotype of bovine rotaviruses.

Animals

Antigenic and genetic analyses of human rotaviruses in Chiang Mai, Thailand: evidence for a close relationship between human and animal rotaviruses.

Serotyping of group A rotaviruses obtained from stools of 158 diarrheic patients in Chiang Mai, Thailand, by ELISA with monoclonal antibodies revealed a yearly change in the prevalence of individual serotypes. Three unusual human rotavirus strains were isolated. Strain Mc35 had subgroup I-serotype 10 antigen and a long RNA electrophoretic type, a property hitherto found only in bovine rotaviruses. RNA-RNA hybridization tests showed that the strain is more closely related genetically to bovine than to human rotaviruses. Strain Mc323, although serologically closely related to serotype 9, had subgroup I specificity and a long RNA electrophoretic type, a characteristic common to nonhuman rotaviruses. Strain Mc345, with an aberrant RNA pattern possibly due to genome rearrangement, had the same antigenic specificity as Mc323. These 2 strains were genetically very closely related to each other and were more related to porcine than to human rotaviruses. These results provide insights into the evolutionary mechanisms of human rotaviruses.

Animals

Non-specific activity of (+/-)-CP-96,345 in models of pain and inflammation.

The non-peptide NK1 receptor antagonist, CP-96,345, and its 2R,3R enantiomer CP-96,344, which is not an NK1 receptor antagonist (IC50 > 10 microM), were evaluated for antinociceptive and anti-inflammatory activities in several classical models of pain and inflammation in the rat. Both CP-96,345 and CP-96,344 reduced carrageenin-induced paw oedema and hyperalgesia, and attenuated the second phase of formalin-induced paw licking with equal potency. These results indicate that NK1 antagonism is not responsible for the activity of (+/-)-CP-96,345 in the above animal models.

Analysis of Variance

Comparisons of rotavirus VP7-typing monoclonal antibodies by competition binding assay.

Three sets of neutralizing monoclonal antibodies (MAbs) used to type the outer capsid protein VP7 of four group A rotavirus serotypes (1 through 4) were compared in competition immunoassays. Reciprocal competition was observed for each of the VP7 type 2-, 3-, and 4-specific MAbs. The VP7 type 1 MAbs exhibited variable competition patterns with other VP7 type 1 MAbs. MAb RV4:3, which has been used to recognize antigenic variants within VP7 type 1 strains, showed reciprocal competition with the four VP7 type 3 MAbs (RV3:1, YO-1E2, 4F8, and 159) using a VP7 type 3 virus (SA11) as antigen. MAb 2C9, also prepared against VP7 type 1, reacted with VP7 type 3 strains and competed with a VP7 type 3 MAb, 159, using RRV as antigen. Use of the different sets of VP7 type-specific MAbs in the enzyme-linked immunosorbent assay permitted the recognition of six antigenic variants within VP7 types 1, 2, and 3 among specimens whose VP7 type could not be determined previously with only one set of typing MAbs. These results demonstrate differences of typing ability among these VP7-specific MAbs and emphasize the need to improve the sensitivity of typing systems by incorporating panels of MAbs reacting with several neutralizing epitopes.

Antibodies, Monoclonal

Hemodynamic effects and pharmacokinetics of long-term therapy with ibopamine in patients with chronic heart failure.

To evaluate the attenuation of the effectiveness of long-term ibopamine therapy, ibopamine was administered in single doses of 100 and 200 mg to 10 patients with chronic heart disease. The hemodynamic studies using Swan-Ganz catheter and pharmacokinetic studies were carried out. Ibopamine was found to increase cardiac output and stroke index and to decrease systemic vascular resistance in this acute study. Six patients underwent long-term therapy with the drug and were evaluated for the development of tolerance. Three out of 5 patients experienced an improvement in NYHA functional class after 12-23 weeks of treatment. There was no attenuation in the effects of ibopamine on hemodynamics, pharmacokinetic parameters remained almost unchanged, and tolerance was not observed. These results suggest that ibopamine is useful as an orally administered anti-heart failure drug.

Administration, Oral

Cardiac output-O2 uptake relation during incremental exercise in patients with previous myocardial infarction.

BACKGROUND: The cardiac output-O2 uptake (VO2) relation, which is thought to be linear and predictable in normal humans, has not been clarified in cardiac patients. We evaluated the relation between cardiac output and VO2 during the incremental exercise test in patients with previous myocardial infarction. METHODS AND RESULTS: Twenty-two patients (age, 58.1 +/- 8.0 years) with previous myocardial infarction performed a symptom-limited exercise test on a cycle ergometer. VO2 was calculated from the expired gas analysis, and cardiac output was measured by a computerized cadmium telluride detector every 10 seconds during exercise. The ratio of increase in VO2 to the increase in work rate (delta VO2/delta WR) below and above the anaerobic threshold (AT) was 11.1 +/- 3.6 and 11.1 +/- 2.9 ml/min/W, respectively, showing no significant difference. However, the ratio of increase in cardiac output to increase in work rate (delta CO/delta WR) below the AT was 50.1 +/- 26.6 ml/min/W and was significantly decreased to 11.8 +/- 25.3 ml/min/W above the AT (p = 0.0002). The decreased delta CO/delta WR above the AT primarily would be due to silent myocardial ischemia produced by exercise, as there was the presence of 201Tl redistribution in 15 of 16 patients in whom myocardial 201Tl scintigraphy with dipyridamole or exercise stress testing was evaluated. delta CO/delta VO2, which has been reported to be approximately 5.5 in normal subjects, was only 4.4 +/- 2.6 at work rates below the AT and was decreased to 1.1 +/- 2.3 at work rates above the AT. CONCLUSIONS: The relation between cardiac output and VO2 during exercise in patients with previous myocardial infarction differs profoundly from that reported in normal subjects. These findings must be considered when we noninvasively estimate the change in cardiac output during exercise by obtaining VO2 in patients with coronary artery disease.

Adult