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Biomedical subjects

Y Takeuchi

Publications and source records attributed to Y Takeuchi.

At least 649 records · Page 36Linked to original sources
PubMed1992

Effects of fatty acids, fatty amines and propylene glycol on rat stratum corneum lipids and proteins in vitro measured by fourier transform infrared/attenuated total reflection (FT-IR/ATR) spectroscopy.

Fourier transform infrared/attenuated total reflection (FT-IR/ATR) spectroscopy was used to examine the effect of fatty acids, fatty amines and propylene glycol (PG) on the molecular mobility of rat stratum corneum lipids and keratinized proteins, using a hydrophobic solute, indomethacin, and a polar solute, 5- and 6-carboxyfluorescein (CF). Treatment of the skin with either oleic acid or oleylamine resulted in significant CH2 C-H asymmetric stretching band shifts and broadening. The extent of spectral alteration varied with the chemical structure of the penetrant. The penetrants increased the lipophilic indomethacin flux and shortened the lag times through the skin in vitro. The plot of frequency changes vs. indomethacin flux or lag time demonstrated a linear relationship, thus indicating that spectral alteration in CH2 C-H stretching regions of stratum corneum lipids may provide a reliable index for characterizing penetrants. The data also showed that the hydrophilic group which attached to the CH2 group in the penetrant molecules did not play a part in the membrane permeability enhancing action. Oleic acid and oleylamine appeared to induce a conformational alteration of the keratinized proteins from alpha-helix to beta sheet. Such alteration was also observed with PG treatment. Accumulation of CF was significantly increased by the PG pretreatment of the skin, thus suggesting that PG-induced protein conformational changes could be related to the enhancement of CF accumulation.

Amines↗
PubMed1992

Computer simulation of agglomeration in the Wurster process.

A simplified model for computer simulation of agglomeration in the Wurster coating process was constructed using droplet size distribution and the relation between the size of agglomerates and the number of primary particles composing them experimentally determined. Computer simulations were applied to the cases where a 2.5% aqueous solution of hydroxypropyl cellulose (containing sodium carboxymethyl cellulose of 10% on a dry basis) was sprayed on four kinds of sharply fractionized lactose powders between 32 and 75 microns. With cores larger than 53 microns, the agitation exerted on particles strongly suppressed the growth of agglomerates, but the fraction of produced agglomerates reached about 50%. The smallest droplet size that was contributable to agglomeration (critical droplet size) was estimated to be 37.1-49.0 microns, increasing with core size, and the weight fraction of droplets larger than this critical size was only 0.5-2.7%, decreasing with increase in core size. The production of even such a minor amount of coarse droplets could be responsible for significant agglomeration.

Chemistry, Pharmaceutical↗
PubMed1992

Destabilization of whole skin lipid bio-liposomes induced by skin penetration enhancers and FT-IR/ATR (Fourier transform infrared/attenuated total reflection) analysis of stratum corneum lipids.

Whole skin lipid bio-liposomes (skin bio-liposomes), in size ranging from 2 to 8 microns, were prepared by a reverse phase evaporation technique using rat full thickness skin. Leakage of an encapsulated fluorescence probe, ANTS (delta-amino-1,3,6-naphthalene-trisulfonate), was measured by adding transdermal penetration enhancers (penetrants) into the medium where the skin bio-liposomes were present. Oleylamine induced a fast release of ANTS from the liposomes compared to lauryl-amine which showed a weak action. With these penetrants, the degree of ANTS release from the prepared bio-liposomes was found to correlate well with the results of frequency changes in the CH-asymmetric stretching band near 2920 cm-1 in the rat stratum corneum. The penetrant which caused relatively strong leakage of ANTS induced the significantly large shift of the peak toward the higher wave-numbers due to the perturbation in the structure of lipids of the stratum corneum. The skin bio-liposomes prepared from the rat full thickness skin could be useful in evaluating the penetrants.

Amines↗
PubMed1992

Synthesis and antitumor activity of fused quinoline derivatives. II. Novel 4- and 7-hydroxyindolo-[3,2-b]quinolines.

Novel indolo[3,2-b]quinoline derivatives (1c--f), which carried a methoxy or a hydroxy group at the 4- or 7-position of the lead compound 1a, were prepared and their antitumor activities against P388 in mice were examined. Except for the 4-hydroxy derivative (1d), these showed remarkably potent activity. Among these compounds, the 7-hydroxy derivative (1f) was the most potent one (optimal dose = 50 mg/kg, the median survival time of treated group/control group (T/C) greater than 330%, cure = 5/6).

Animals↗
PubMed1992

[Determination of protoporphyrins in blood using HPLC. Standardization of protoporphyrins and interlaboratory comparison of analyses].

1) In order to compare the results of determination of protoporphyrin IX (PP) and zinc protoporphyrin IX (ZP) using HPLC, the preparation procedures for standard solutions of PP and ZP were studied at four laboratories. According to the methods mutually agreeable to the four laboratories, the absorption values using UV-Vis spectrometer from the 4 laboratories were found to be identical. 2) The total of 28 whole blood samples obtained from the same workers whose Pb-B levels ranged from 2.9 to 87.9 micrograms/dl were sent to the 4 laboratories for determination of PP and ZP. The laboratories were allowed to use their own HPLC apparatus, column, mobile phase and fluorometric detectors, although the same procedures were used to prepare the standard solutions of PP and ZP. The results showed that significant biases in ZP and PP levels were found between two out of the 4 laboratories, but the ZP values corrected by the recovery rate showed no statistical difference among the laboratories. 3) Blood levels of ZP, total protoporphyrin (TP, calculated by PP+ZP/1.1), and PP determined by HPLC method correlated well with free erythrocyte protoporphyrin (FEP) determined by the method of extraction into the acidic solvent. The correlation coefficients between Pb-B and log TP, ZP, FEP or PP were 0.82-0.84, 0.80-0.83, 0.786, or 0.70-0.73, respectively. 4) The coincident ratios of PP/TP obtained at 4 laboratories ranged from 12.1 to 19.0%. These values were within a relatively narrow range, although two different kinds of organic solvents (DMF: N',N'-dimethylformamide or Methanol/triton-X 100) were used in the extraction steps.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromatography, High Pressure Liquid↗
PubMed1992

[Effect of hydrolysis conditions on the determination of urinary 2,5-hexanedione in workers exposed or not exposed to N-hexane].

In order to determine the optimal conditions of acid hydrolysis for urinary 2,5-hexanedione (HD) measurement, the effects of urine pH or volume of HCl added to urine and hydrolysis period were studied using gas chromatography-mass spectrometry (GC-MS). When 0.3 ml of concentrated HCl was added to 3 ml of urine, complete hydrolysis to liberate HD was attained 2 h after the start of heating at 100 degrees C for urine from non-exposed subjects. On the contrary, in urine from exposed subjects most of HD was liberated in 30 min at 100 degrees C, suggesting that the urinary substrates converted to HD by acid hydrolysis were different between exposed and non-exposed subjects. It was confirmed that hydrolysis for 2 h at 100 degrees C with 0.3 ml of concentrated HCl added to 3 ml of urine gave the most reliable levels and the greatest amounts of HD in both urine from exposed and non-exposed subjects. Reference values were determined by the hydrolysis conditions presented here. In 84 males, 52 females, and 136 with sexes combined the urinary HD levels were 0.35, 0.49, and 0.39 mg/l (geometric mean), respectively. Urinary HD levels determined without hydrolysis (free HD) were less than 0.006 mg/l in 31 control subjects examined. In urine from exposed subjects the amount of free HD was about one-fifth of the total HD (free plus conjugated HD) as determined with acid hydrolysates, although the percentage of free to total HD varied from 0.4 to 28%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Masking in bone-conduction testing--proposal of ABC method].

A new strategic masking technique, namely the ABC method, has been developed. In performing this method of measuring thresholds of bone-conduction, the vibrator is placed at the forehead with both ears occluded by air-conduction earphones. One of the earphones is for masking noise and the other is a dummy which balances out the occlusive effect of the test ear against the nontest ear. The ABC method is based on the ABC rule that, in bone-conduction testing, the effective masking noise level necessary to block out the nontest ear can be calculated by a simple equation: right AC (A) + left AC (B)--unmasked BCu (C) under the assumption that the BCu belongs to the nontest ear. In some cases of hearing loss, the above noise level might produce overmasking, then an additive safety noise level, BCu + Interaural Attenuation, is employed. This method offers testers step by step directions which consist of indications of the noise level and a criterion for determining whether the measured bone-conduction is free from cross hearing and overmasking for the given configuration of air-conduction of both ears, BCu, and the masking noise level. Compared to the well known Plato method, in which measurements of thresholds are repeated at several masking noise levels in order to find a single bone-conduction threshold, the ABC method can essentially find the threshold at only one masking noise level. Therefore the ABC method makes it possible to save a great deal of time in performing bone conduction testing.

Audiometry↗
PubMed1992

[A contralateral external carotid-middle cerebral artery bypass operation--a new procedure of vascular reconstruction in the treatment of head and neck carcinoma requiring carotid resection].

In the treatment of head and neck carcinoma involving the carotid artery, resection of the carotid artery and direct reconstruction using a vein graft has commonly been employed to reduce the incidence of cerebral ischemic complications. But the procedure of carotid grafting itself carries the risk of preventing complete tumor clearance. And contamination due to salivary fistula, particularly in cases of meso or hypopharyngeal carcinoma, may result in graft rupture or thrombosis. To overcome these difficulties, the authors have developed a new surgical procedure, namely, a contralateral external carotid-middle cerebral artery bypass operation. This bypass system is designed at directly supplying the cerebral hemisphere on the carotid ligation side through a vein graft running entirely outside the cervical operative field. The vein graft is anastomosed end-to side to the external carotid artery of the opposite side. Then it is placed subcutaneously in front of the auricle, above the zygomatic arch, frontal subgaleal space and anastomosed end-to-side to the recipient artery, the ascending branch of the middle cerebral artery, in the Broca area of the carotid ligation side. The neck is incised almost the same manner as in parotidectomy, with a slightly longer cervical extension, and the scalp by bilateral coronal incision of Sutta. A frontotemporal osteoplastic craniotomy of the involved side is performed. The length of the saphenous vein used is about 50cm. This surgical procedure requires no transient internal or external shunt. The common carotid artery can be ligated safely after confirming good post-anastomotic bypass flow using an electro-magnetic blood flow meter.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[Left atrial ejection performance in heart failure as assessed by transesophageal Doppler echocardiography].

To investigate the left atrial ejection performance in heart failure, we observed both the transmitral (TMF) and pulmonary venous flow waves (PVF) by transesophageal Doppler echocardiography in 20 patients with heart failure (16 males, 4 females, 56 +/- 13 years old). In 7 of 20 patients, pulmonary capillary wedge pressures (PC) were also obtained within 72 hours after the transesophageal Doppler echocardiographic examinations. A reversal flow on PVF during atrial systole (atrial backward ejection flow) was observed in all of the 20 patients. Corrected atrial pre-ejection period correlated significantly with PC (r = -0.76, p < 0.05), indicating that the period was shortened in accordance with left atrial Starling's law. This period correlated significantly with both the duration and the time velocity integral of atrial backward flow (r = -0.72, p < 0.005; r = -0.55, p < 0.05, respectively), but not with the atrial ejection time nor with the time velocity integral of atrial systole. These results suggest that in some cases of heart failure, left atrial contractile function is preserved despite the marked augmentation of left atrial afterload, resulting in a decrease of the left atrial forward ejection and an increase of the left atrial backward ejection. Thus, the observations of TMF and PVF by transesophageal Doppler echocardiography are useful for assessing the left atrial ejection performance in patients with heart failure.

Adult↗
PubMed1992

[Clinical and echocardiographic evaluation of the effects of atrial defibrillation in patients with idiopathic cardiomyopathy].

To elucidate the effects of atrial defibrillation in patients with idiopathic cardiomyopathy, we clinically and echocardiographically assessed 6 patients with hypertrophic cardiomyopathy (HCM) and 7 patients with dilated cardiomyopathy (DCM). Their mean age was 57 +/- 14 years and the mean duration of their atrial fibrillation (Af) was 47 +/- 29 days. There were no differences in age and the duration of Af between the HCM and DCM groups. We assessed the effects of defibrillation on the NYHA functional classification, heart rate (HR), systolic blood pressure (S-BP), M-mode echocardiographic data (LVDd, LVDs, %FS, LAD) and transmitral pulsed Doppler echocardiographic findings (peak velocity, time-velocity integral of rapid and atrial filling waves). These indices were obtained before and 52 +/- 22 days after defibrillation, and were compared with each other. 1. HR decreased (HCM: 87 +/- 16-->58 +/- 7/min, DCM: 93 +/- 19-->70 +/- 14/min) and total left ventricular filling increased (HCM: 6 +/- 1-->11 +/- 4 cm, DCM: 6 +/- 1-->10 +/- 2 cm) after defibrillation, and the increment of %FS (HCM: 36 +/- 6-->41 +/- 6%, DCM: 16 +/- 6-->25 +/- 11%) was observed. Four of 6 HCM patients and 5 of 7 DCM patients also improved with regard to the NYHA classification. 2. After defibrillation, LVDd increased in HCM (42 +/- 4-->47 +/- 4 mm), but not in DCM. However, LVDs decreased in DCM (52 +/- 9-->44 +/- 12 mm), but not in HCM. We concluded that atrial defibrillation had a beneficial effect on the recovery of the left ventricular function both in HCM and DCM due to the reduction in HR and increase in left ventricular filling. The mode of LV functional improvement after defibrillation varied depending on the state of patient's basal pathophysiology .

Adult↗
PubMed1992

[Double valve replacement for secondary atrioventricular regurgitation due to dilated cardiomyopathy--a case report].

A successful surgical case of double valve replacement for a patient with dilated cardiomyopathy was performed. A 45-year-old man was admitted to our hospital with paroxysmal atrial fibrillation and congestive heart failure. Echo cardiogram and cineangiography showed dilatation and decreased contraction of the left ventricle. A diagnosis of dilated cardiomyopathy was established since neither coronary artery disease nor valvular disease were observed. He was treated with medication of diuretics and pacemaker implantation. However, mitral and tricuspid regurgitation occurred and progressed 7 years later. Since then, he repeated admission and discharge against the strong medication. He became medically uncontrollable at the age of 58. Because of this, surgical treatment had to be considered. Double valve replacement for mitral and tricuspid valve was performed on September, 1989. Avoidance of cardiopulmonary bypass was only possible with the aid of catecholamine. Poor left ventricular function and pleural effusion frequently shown on chest X-ray film complicated the postoperative course. And with hospital treatment, he discharged three months after the operation. He has been doing well without any significant complaint during the past two years and cardiomegaly has been decreasing as well.

Cardiomyopathy, Dilated↗
PubMed1992

[Malignant lymphoma developing from the wall of chronic empyema following artificial pneumothorax].

A 60-year-old man who had had chronic empyema following an artificial pneumothorax for pulmonary tuberculosis when he was 26 years old developed malignant lymphoma of the chest wall. The patient was admitted because of right pyothorax as a result of pseudomonas aeruginosa infection and underwent right thoracotomy. During lavage of the right thoracic cavity a tumor was found arising from the empyematic wall. Pathologic examination revealed that it was malignant lymphoma (diffuse large, immunoblastic, B cell type). Treatment with VEAP-Bleomycin elicited a good response. Seven months after chemotherapy, the patient underwent thoracoplasty in addition to packing the cavity with the latissimus dorsi and the greater omentum. Following this, the patient received chemotherapy once a month for one and a half years, after which he was kept under close observation without treatment. Complete remission has now lasted for 49 months since the initial treatment. This is the first reported lymphoma case with closure of the empyematic wall and is remarkable since this patient has remained in complete remission for the last two years without any treatment.

Empyema, Pleural↗
PubMed1992

[Comparative studies of various conduits for myocardial revascularization with Kawasaki disease].

Between October 1976 and December 1991, 36 patients with Kawasaki disease underwent coronary bypass surgery. Comparisons were made from the postoperative morphologic condition of 4 conduits; saphenous vein graft (SVG n = 27), left internal thoracic artery (LITA n = 22), right internal thoracic artery (RITA n = 5) and gastroepiploic artery (GEA n = 8). The patency rate of arterial grafts was 100% at 1 month after surgery, and kept as high as 94.7% at 1-3 years after surgery. On the other hand, the patency rate of SVG was 90% at 1 month, but decreased to 52% at 1-3 years postoperatively. Arterial grafts sometimes showed string sign at 1 month after surgery, but the length and the diameter increased during 1 year after surgery. The internal thoracic artery showed superior flow potential compared with GEA. Thus, the internal thoracic artery is the first choice and GEA is the second as the graft material with Kawasaki disease. Long-term result of SVG was very poor, so coronary revascularization only by the arterial grafts is recommended.

Adolescent↗
PubMed1992

[Long-term effect of medical treatment in patients with chronic aortic regurgitation].

We often experience patients with chronic severe aortic regurgitation (AR) whose cardiac function significantly improves by medications, especially by vasodilator therapy. To find the factors determining the response to pharmacologic treatment, we studied 20 patients with chronic AR with dilated left ventricle (end-diastolic dimension > or = 55 mm) using echocardiography; 9 patients with significant improvement (delta Ds < or = -3 mm: improved group) and 11 without improvement (unchanged group). In the initial evaluation, systolic blood pressure and left ventricular relative wall thickness (Thd/Dd) were greater and left ventricular end-diastolic dimension was smaller in the improved group than in the unchanged group. During the follow-up period, systolic blood pressure and end-systolic wall stress decreased significantly and absolute and relative wall thickness increased significantly in the improved group, however, they remained nearly the same in the unchanged group. Significant negative correlation was observed between Thd/Dd and delta Ds. In conclusion, cardiac function in some patients with chronic AR can be improved by pharmacologic treatment, and in such cases, the Thd/Dd ratio could be a parameter of the response to pharmacologic treatment.

Adult↗
PubMed1992

[A case of isoniazid (INH)-induced pneumonitis].

A 58-year-old man was referred for the evaluation of a lung nodule on chest X-ray. On admission, chest X-ray showed a solitary nodule with cavitation in the left lung field. Histological examination revealed epithelioid cell granulomas and the diagnosis of pulmonary tuberculosis was made. He was treated with INH, ethambutol (EB), and rifampicin (RFP). On the 16th day of treatment, he developed dry cough and high fever. On the 20th day, dyspnea developed and PaO2 was decreased to 38.2 Torr. Chest X-ray showed new widespread infiltrates in both lung fields and bilateral pleural effusions. The size of the cavitary lesion was decreased. Transbronchial biopsy specimen showed slight interstitial thickening, lymphocyte infiltration, and multiple granulomas. Drug lymphocyte stimulation test was positive only with INH (230%). INH-induced pneumonitis was highly suspected. All drugs was discontinued and hydrocortisone 2400 mg daily was started. He soon became afebrile, and dyspnea and dry cough resolved. Chest X-ray film showed resolution of infiltrative shadows. He was subsequently successfully treated with streptomycin, EB, and RFP without any adverse effects. To our knowledge, this is the sixth reported case of INH-induced pneumonitis.

Alveolitis, Extrinsic Allergic↗
PubMed1992

[Augmentation of left ventricular slow filling in hypertrophic cardiomyopathy].

To investigate the significance of augmentation of left ventricular slow filling, trans-mitral flow (TMF) was echocardiographically observed through pulsed Doppler method in 116 patients with hypertrophic cardiomyopathy (HCM), 74 with dilated cardiomyopathy (DCM), 27 with mitral regurgitation (MR), 86 with old myocardial infarction (OMI) and 80 normal controls (C). The slow filling-wave (SFW) in TMF was defined as the filling wave with obvious peak velocity during slow filling phase. The peak velocities (E, A, S) of the early filling, the atrial contraction and the slow filling waves were measured. The SFW was divided into two patterns according to the S and E ratio: large SFW (S/E greater than or equal to 1/2) and small SFW (S/E less than 1/2). 1) The small SFW was more frequently, but not significantly, observed patients with MR (37%) than in normal subjects (18%), patients with HCM (10%), DCM (4%) and OMI (7%). However large SFW was observed in 16 patients (14%) with HCM, but not in normal subjects and patients with other cardiac diseases excluding one patient with DCM. 2) In normal subjects and patients with DCM, OMI and MR, those with small SFW had larger E and smaller A/E than those without small SFW. However in patients with HCM, there was no difference in these indices (E and A/E) according to whether the patients were with or without SFW. 3) In HCM, patients with large SFW had significantly smaller E and significantly larger isovolumic relaxation time than those without SFW. Thus, appearance of the large slow filling wave, which might be caused by abnormal relaxation of the left ventricle, was frequently observed in patients with HCM.

Adult↗