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Biomedical subjects

K Katoh

Publications and source records attributed to K Katoh.

At least 181 records · Page 10Linked to original sources
PubMed1992

[Influence of increased 201Tl lung uptake on the myocardial viability of the patients with dilated cardiomyopathy under congestive heart failure].

Influence of increased 201Tl lung uptake on the myocardial viability was studied in 15 patients with dilated cardiomyopathy under congestive heart failure. Rest and 4 hours delayed 201Tl SPECT were obtained. At the same time anterior planar images were collected. In 10 patients of 15 patients 201Tl lung heart ratio in SPECT (LHR) was larger than that in planar images. Maximal 201Tl lung uptake was noted at the lower left lung adjacent to the heart. In the delayed images 201Tl lung uptake diminished. In 10 patients the value of LHR in the delayed images was less than 0.5. By comparing initial images with delayed images it was proved to be difficult to determine the myocardial margin adjacent to the increased 201Tl lung uptake. In 2 patients lateral defects were concealed by the increased 201Tl lung uptake. In the remaining patients lateral wall was similar to the hypertrophic myocardium. The effect of scatter due to the increased 201Tl lung uptake was noted in the neighboring myocardium. In most cases %201Tl uptake in the septum was relatively depressed by increased %201Tl uptake in the lateral wall. In the delayed images pseudo-redistribution was noted in the septum. Mean value of differences in %201Tl uptake between initial and delayed images was 8 (2-15)%. It was concluded that in case of increased 201Tl lung uptake SPECT could not accurately estimate myocardial viability by initial images and delayed images were necessary for precise estimation.

Adult↗
PubMed1992

[A prospective study of psychosomatic reaction to hysterectomy].

Psychosomatic reaction to hysterectomy was prospectively studied by means of psychological tests and a questionnaire. One hundred and twenty patients who had simple hysterectomy were examined before and as long as one year after operation. The mean score for A-state, a state anxiety scale, was high before operation and rapidly declined postoperatively. SRQ-D and CMI, which represent depressive and neurotic states, respectively, showed rather high scores before and 2 weeks after operation. Mean scores in these psychological tests declined to a plateau within 6 months after operation, and there were less psychological and physiological symptoms and there was improved physical activity, showing that most patients can over come psychosomatic problems caused by hysterectomy. A close correlation was observed between the results of psychological tests and the number of psychological symptoms. Forty patients with a high SRQ-D score showed abnormality in other scales. Psychosomatic disorders associated with hysterectomy are characterized by various symptoms but mainly by a depressive state. High SRQ-D patients were divided into three subgroups: A) the SRQ-D score is constantly high, B) the SRQ-D is high for the first several weeks, and C) the score increased after discharge. Patients in each subgroup showed signs of a characteristic personality. These results show the presence of a different psychosomatic approach to the patients personally.

Anxiety↗
PubMed1992

[Ovarian epithelial tumors of borderline malignancy].

Ovarian tumor is known to show histological variation. Each tumor shows various clinical behavior. Ovarian epithelial tumors consist of several types of histological findings. Epithelial tumors can be classified into benign, borderline malignancy and malignant for their biological behavior. Recently the therapeutic effectiveness against ovarian cancer is increasing in order to establish the operation technique and development of chemotherapeutic method with cisplatin. Therefore it is important that borderline malignant tumors which are said to have a good prognosis be defined from obviously malignant tumors to evaluate accurately the effectiveness of the therapy against the ovarian cancer. On the other hand, borderline malignant tumors with characters of a malignant tumor, must be distinguished from benign adenoma because long-term follow up is required. However, it is difficult to make an exact histological diagnosis of benign adenoma, borderline malignancy and malignancy because the histological criteria of borderline malignancy is lacking in concreteness. The histological criteria should be defined more clearly and concretely. For example, mitotic counts per 10 HPF of borderline malignancy and DNA ploidy. Next, because of good prognosis, we need a quick therapeutic guide line for borderline malignancy, especially for stage I and young women.

Adult↗
PubMed1992

[Alpha 1-antitrypsin deficiency with bronchiectasis in two sisters].

Two sisters with alpha 1-antitrypsin deficiency and bronchiectasis are reported. The 53-year-old older sister (propositus) had pneumonia 3 times during her forties. She developed dyspnea on exertion in February, 1988, and a few months later she was seen at our hospital. Her serum alpha 1-antitrypsin level was 11 mg/dl. Vascular markings on chest X-ray were mildly decreased. Bronchography showed generalized cystic bronchiectasis. The younger sister was seen at our hospital at the age of 50. She had been in good health until one year previously when she had developed pneumonia, and thereafter she had suffered from productive cough and dyspnea on exertion. Her alpha 1-antitrypsin level was 22 mg/dl. Chest X-ray showed ring-like shadows and tram lines. Chest CT scans of both sisters revealed cystic changes, dilatation of bronchi, and the connection of these lesions diffusely. The alpha 1-antitrypsin phenotype of these sisters was found to be PiSiiyama (homozygote). Family study revealed that alpha 1-antitrypsin levels of 7 members were intermediate and no members had symptoms. We consider that bronchiectasis may have been related to alpha 1-antitrypsin deficiency in these sisters.

Bronchiectasis↗
PubMed1991

Dynamic sweating response of man to infrared irradiation in various spectral regions.

In an attempt to detect differences in the thermal effect of infrared irradiation of different wave-lengths, transient sweating response to infrared irradiation in various spectral regions was examined. In Series 1, the ventral or dorsal surface of the nude subject was irradiated repetitively for a period of 4 min (2 min on, 2 min off) by each of three kinds of infrared heaters with main emissivity in 'near-infrared' (NIR; 0.7-2.8 microns), 'intermediate-infrared' (MIR; 1.5-5.8 microns), and 'far-infrared' (FIR; 2.8-25 microns) regions. The sweating response on a non-irradiated area tended to be the greatest with MIR, while the magnitude of the sweating response on the irradiated area showed no consistent differences among various wavelengths. The results infer that MIR stimulated cutaneous thomoreceptors most effectively, while its direct effect on local sweat gland activity was minimal. In Series 2, the effects of 9-12 min irradiations in more restricted ranges of wavelength were compared by the combination of the three kinds of heaters with filters (translucent to wavelength ranges of 1.3-2.7, 2.7-3.5, 3.6-8.0 microns, respectively). The sweating response on a remote area was predominantly greater with the range of 2.7-3.5 microns than with the other wavelength ranges, while the local effect on sweating was minimal with this range. The results of Series 2 reinforce those of Series 1, indicating that the degree of stimulation of cutaneous thermoreceptors and of direct thermal effect on sweat gland activity differ with spectral regions incident on the skin, thus affecting local and remote effects on the sweating response.

Adolescent↗
PubMed1991

Availability and limitations of thallium-201 myocardial SPECT quantitative analysis: assessment as daily routine procedure for ischemic heart disease.

To determine the availability and limitations of the detection of ischemic lesions by stress thallium-201 myocardial SPECT as the daily routine procedure, we compared and evaluated the detectability of the quantitative analysis (%uptake and washout rate (WR)) and visual evaluation in 104 patients with effort angina and 17 normal subjects. Visual evaluation combined with WR analysis resulted in significantly higher sensitivity (88.0%) but lower specificity (60.2%) than the other methods. The sensitivity by visual evaluation was quite low in multivessel disease (MVD), and in the regions supplied by mild coronary stenosis or by the left circumflex artery. These were markedly improved by combining visual evaluation and WR analysis, but sensitivity in the MVD group was unsatisfactory even with this analytic method in comparison with the single vessel disease group. One of the causes of low sensitivity in the MVD group might be the "true negative": No induction of the ischemia in the regions of milder stenosis, or the regions supplied by the collateral coronary flow. We therefore conclude that the combination of visual evaluation as a qualitative analysis and WR analysis as a quantitative analysis, is the most useful daily routine procedure as a screening test for detecting ischemia.

Aged↗
PubMed1991

Passage and digestibility of lucerne (Medicago sativa) hay in Japanese sika deer (Cervus nippon) and sheep under restricted feeding.

The mean retention time (MRT) of stained hay through the whole digestive tract and its digestibility were measured in Japanese sika deer (Cervus nippon) and were compared with those in sheep when lucerne (Medicago sativa) hay was fed at 10, 20 and 30 g/kg body-weight. The recoveries in faeces of plastic particles with five specific gravities were also measured in deer. MRT for deer was significantly shorter than that for sheep at 10 and 20 g/kg feeding levels. The digestibilities of dry matter, organic matter, and neutral-detergent fibre were significantly lower for deer than for sheep at 30, 30 and 10 g/kg feeding levels respectively. The recovery rates of plastic particles were increased, but the ruminated rates were decreased, with increasing specific gravity in deer. These results suggest that the lower digestibility of lucerne hay in Japanese deer may be due to a shorter MRT compared with sheep.

Animals↗
PubMed1991

Comparative studies of angiotensin converting enzyme inhibitors with and without the SH-radical.

This study was conducted to evaluate the effects of an SH-radical in an angiotensin converting enzyme (ACE) inhibitor on PGI2 generation, intracellular cGMP, and Ca2+ kinetics in vascular endothelial cells. In the cultured human umbilical vein endothelial cells, the non-SH containing ACE inhibitors, delapril and enalapril, did not result in significant changes in cGMP concentrations. By comparison, captopril significantly (P less than .01) increased cGMP concentrations. Only captopril showed a significant (P less than .01) effect on 45Ca kinetics in cultured human vascular endothelial cells. Captopril also decreased PGI2 generation in vascular endothelial cells. These effects were not seen with delapril or enalapril. The significance of the SH moiety in ACE inhibitors remains controversial. However, these results suggest that there could be differences in the vascular actions of ACE inhibitors related to the presence or absence of SH radical.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1991

Effect of cyclic GMP and sulfhydryl on prostacyclin production by human vascular endothelial cells.

The relationship between sulfhydryls and cGMP has been observed in several biological processes. Captopril is a sulfhydryl-containing angiotensin converting enzyme (ACE) inhibitor, that decreases PGI2 production in cultured human vascular endothelial cells. Enalapril does not appear to have this property. The role of cyclic GMP (cGMP) and sulfhydryls in the regulatory mechanisms in captopril-induced PGI2 production and Ca++ kinetics was investigated. Bradykinin and Ca ionophore A23187 enhanced PGI2 production, and increased the cytosolic free Ca++ concentration ([Ca++]i). It was observed that 8-bromo cGMP increased intracellular cGMP concentration ([Ca++]i), and decreased PGI2 production without changing [Ca++]i. Sulfhydryl containing compounds such as captopril, N-acetylcysteine and glutathione decreased PGI2 production via increased [cGMP]i. Enalapril, an ACE inhibitor without sulfhydryls, has no effect on PGI2 production, [Ca++]i and [cGMP]i. These results suggested that the presence of sulfhydryl groups is an important factor in the ability of vasoactive substances to induce PGI2 production.

Acetylcysteine↗
PubMed1991

Stunned myocardium and sympathetic denervation--clinical assessment using MIBG scintigraphy.

To evaluate the clinical relationship between stunned myocardium and the sympathetic nervous system, 6 patients who had stunned myocardium accompanied by T wave inversion underwent simultaneous 123I-metaiodobenzyl guanidine (MIBG) scintigraphy and thallium scintigraphy. All patients showed abnormal filling defects on the MIBG scintigrams in the areas with stunned myocardium but the thallium scintigrams were almost normal. The extent of the defects in these 6 patients was determined on the MIBG scintigrams using a Bull's eye display. The defects were found to be larger than those in 4 patients with angina pectoris, and those in 4 patients who had previously shown T wave inversion but had a normal electrocardiogram at the time of examination. Thus, it is suggested that sympathetic denervation is one of the mechanisms causing stunned myocardium.

3-Iodobenzylguanidine↗
PubMed1991

Effects of injection site on the accuracy of thermal washout right ventricular ejection fraction measurements in clinical and model investigations.

The purpose of this investigation was to improve the accuracy of measurement of thermal right ventricular ejection fraction (RVEF) using the modified Swan-Ganz catheter. Three serial ejection fractions (EFs) (EF1, 2, 3) and the mean were calculated, based on Holt's theory. RVEFs were compared between right ventricular (RV) and atrial (RA) injection in ten intensive care unit (ICU) patients using a modified catheter having RV and RA orifices (15 cm and 30 cm from the distal end, respectively), and paired duplicate (two patients) or triplicate (eight patients) measurements were performed. To determine what factors interfere with RVEF, a model heart (with diastolic volume of 150 ml) was constructed, in which model injection of cold water to the direct inflow tract (RA), to the direct mixing chamber (RV), or through the catheter running in the inflow tract were compared. When EFs were compared between RV and RA injection, those for the former were greater (RV vs RA in EF1 and EFmean: 0.46 +/- 0.15 vs 0.23 +/- 0.11 in EF1, and 0.45 +/- 0.13 vs 0.28 +/- 0.11 in EFmean, mean +/- SD, p less than 0.01). When the serial EFs were compared in each injection type, in the RV injection EF3 was the smallest as was EF1 in the RA injection. The same phenomenon was observed in the model as in the patients, and moreover when cold water was injected in RA through a catheter running through the circuit, EFs were greatly underestimated (EF1 = 0.29 +/- 0.02 at preset EF = 0.4). We conclude that these phenomena were caused by sluggish movement of the cold indicator from RA to RV when injected into RA, and by interference with the cooled cardiac chamber and catheter. Consequently, the first or second EFs obtained from RV injection might be closest to the actual values because of the least interference with those factors.

Adult↗
PubMed1991

[A study on blood pressure variation--the clinical validation of continuous direct blood pressure recording in patients with pheochromocytoma].

UNLABELLED: Continuous direct arterial blood pressure (intra-brachial) recording (CDPR) was performed in the ward in 7 patients with documented pheochromocytoma (PHEO). They consisted of 4 patients with adrenal medulla and 3 with ectopic PHEO in the urinary bladder. Recordings were also taken from 11 patients with mild and moderate essential hypertension (EHT). The arterial pressure variations throughout the day and night were detected for either 24 hours or 48 hours unrestrictive recording (CDPR) transmitted by telemetry (SANEI INST. 270), and analyzed by signal processor (SANEI 7T17). The measurement through CDPR was repeated in all the patients with PHEO on three occasions; (1) observation period (non-medication period), (2) medical treatment period with prazosin and, (3) post-operative period. RESULTS: (1) In the non-medication period, all the patients with PHEO were characterized by a steep elevation of the arterial pressure and a variability of the high blood pressure events more remarkably than the patients with EHT. The changes in arterial pressure in the patients with PHEO were accompanied by headaches, feelings of fear, trembling, sweating and palpitation. (2) At the medication period, prazosin sufficiently suppressed the sudden elevation of blood pressure. However, the paroxysmal elevation of blood pressure after voiding was not prevented in 2 of 3 patients with ectopic PHEO in the urinary bladder. Urinary and plasma catecholamine (CA) were normal in 2 of our 3 cases. Voiding elevated plasma CA which provided better diagnostic determinant in patients with this bladder tumor as well as the CDPR. (3) The CDPR provided good operative removal results through the 24-hour monitoring, and the recovery was uneventful. CONCLUSION: Evaluation of blood pressure elevation is a clue to the diagnosis of hypertension. Monitoring of the arterial blood pressure variation through 24 hours by CDPR was helpful for detecting a precise arterial pressure fluctuation, since the duration of the elevation was short and was steeply changed especially in patients with PHEO.

Adrenal Gland Neoplasms↗
PubMed1991

[A study on crosstalk correction in dual energy acquisition of 123I-MIBG and 201TlCl in myocardial SPECT].

In the simultaneous dual energy acquisition, energy spectrums of two radionuclides crosstalk each other and this phenomenon is a cause of the poor quality of images. In order to obtain the image of high quality in dual energy acquisition of 123I-MIBG and 201TlCl, a crosstalk correction method was originated. The crosstalk from 201Tl to 123I window (R1) and the crosstalk from 123I to 201Tl window (R2) were determined by the cardiac phantom studies. R1 and R2 showed almost constant value throughout the myocardial wall. The crosstalk correction was performed using R1 and R2. After the crosstalk correction, the defect region placed in the cardiac phantom was detected more clearly both in visual interpretation and in quantitative analysis. The crosstalk correction method with R1 and R2 was applied to some clinical cases. By the crosstalk correction, the quality of image was improved and a false defect caused by crosstalk disappeared in a clinical case. The crosstalk correction was considered to be useful for improving the quality of image on dual energy acquisition.

3-Iodobenzylguanidine↗
PubMed1991

Effect of aging on endothelin-induced prostaglandin I2 release in isolated hind legs of the spontaneously hypertensive rat.

We evaluated the effect of aging on spontaneous release of prostaglandin I2 (PGI2; measured as 6-keto-PGF1a) as well as on endothelin-induced release of PGI2 from isolated hind legs perfused with Krebs-Ringer solution in 5-week-old, 10-week-old and 40-week-old Wistar-Kyoto rats (WKY) and age-matched spontaneously hypertensive rats (SHR). The spontaneous release of PGI2 was stable up to 40 minutes for both strains. The amount of the spontaneous release of PGI2 tended to fall with advancing age in WKY, while it remained unchanged in SHR. Porcine endothelin-1 (pET-1) added to the perfusion medium (2 x 10(-12)-2 x 10(-10) M) increased PGI2 release in a dose-dependent fashion in both strains regardless of age. However, the maximal increase of PGI2 release evoked by endothelin (2 x 10(-10) M) was significantly greater in 40-week-old SHR compared with age-matched WKY. These results not only suggest that there exists a much greater reservoir of vascular PGI2 synthesis in SHR, but also imply that the enhanced release of PGI2 in response to endothelin, the most potent vasoconstrictor known, may function as a factor or a modulator to attenuate endothelin-induced vasoconstriction in senescent SHR.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

[Usefulness of thallium-201 myocardial SPECT using dipyridamole infusion combined with low level exercise for the detection of the ischemic heart disease--comparison with SPECT images by maximum physical exercise in the same patients].

To evaluate the usefulness of thallium-201 myocardial SPECT using dipyridamole infusion combined with low level exercise (Dp-method) for the detection of the ischemic heart disease, we performed both Dp-method and maximum physical exercise SPECT (Ex-method) in the same 28 patients, and compared the results obtained by the two methods. In the visual evaluation, the detectability of each stenotic coronary territory by Dp-method tended to be higher than that by Ex-method (accuracy 71% vs 67%). The severity of the defect and the degree of the redistribution were higher by Dp-method than those by Ex-method. In the washout rate (WR) analysis in 14 angina pectoris patients, the detectability (accuracy) by Dp-method was significantly higher than that by Ex-method (86% vs 64%; p less than 0.05). In comparison of mean WR values in normal subjects (10 cases for Dp-method and other 8 cases for Ex-method), mean WR by Dp-method was as high as that by Ex-method and the deviation of WR value among subjects was very small. This was probably due to the effect of the low level exercise. These results suggested that Dp-method was more excellent than Ex-method in the evaluation of the ischemic heart disease, and was a useful method of the daily routine work. The incidence of chest symptom and the electrocardiographic ST-depression was as high by Dp-method as that by Ex-method. The filling defects in Dp-method were thought to be induced not only by the difference in the relative increase of the myocardial perfusion, but also by the myocardial ischemia.

Adult↗
PubMed1991

Electron microscopic visualization of actin filaments in the early embryo of Drosophila melanogaster: the use of phalloidin and tropomyosin.

Various specimen preparations for thin-section electron microscopy were tested to better preserve and visualize actin filaments in the cortex of the early embryos of Drosophila melanogaster. When embryos were treated with phalloidin prior to fixation, many actin filaments were observed in their cortex comparable to the staining with fluorescently labeled phalloidin in light microscopy. Then we used various fixatives containing phalloidin. As far as we examined, actin filaments were best preserved in the specimen fixed with 2.5% glutaraldehyde, 2% paraformaldehyde in 0.1 M sodium phosphate buffer or in 0.1 M PIPES buffer (1 mM EGTA and 1 mM MgCl2) containing 10 microM phalloidin and 0.1% saponin. When embryos were glycerinated and then treated with tropomyosin before fixation, actin filaments were well visualized as thicker, uniform-sized filaments, though the number of filaments decreased probably owing to glycerination. This suggests that, like heavy meromyosin and its subfragment-1, this protein may protect actin filaments from being disrupted by chemical fixation. Using these improved fixation procedures, we successfully examined the distribution of actin filaments in the Drosophila embryo cortex during cellularization. These methods may be applicable to stabilize labile actin filaments in other types of cells.

Actin Cytoskeleton↗
PubMed1991

[Release of endothelin from isolated perfused human umbilical vein. I: Effect of ionomycin].

Endothelin-like immunoreactivity (ET-LI) was directly measured in the perfusate from the isolated human umbilical vein perfused with Krebs-Ringer solution. The identity of the immunoreactive peptide was confirmed as ET-1 by high-performance liquid chromatography. The rate of release of ET-LI was 86.7 +/- 25.9 (SE) fmol during the first perfusion period of 30 min, and it remained stable at least for 4 hours. Calcium ionophore ionomycin, added to the perfusion medium (10(-7)-10(-6) M), stimulated the ET-LI release in a dose-dependent fashion; it increased the rate of release by 29.1% and 143.4% over the control at the concentrations of 10(-7) and 10(-6) M, respectively. These results taken together with previous observations of synthesis of ET in cultured vascular endothelium provide direct evidence for local generation and subsequent release of ET from vascular beds of human beings.

Calcium↗