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Biomedical subjects

Y Yagi

Publications and source records attributed to Y Yagi.

At least 163 records · Page 9Linked to original sources
PubMed1990

Role of Lugol dye endoscopy in the diagnosis of early esophageal cancer.

To evaluate the role of Lugol dye endoscopy in diagnosing early esophageal cancer, we reviewed findings of dye endoscopy and those of conventional endoscopy in 17 early esophageal cancers that were demonstrated as unstained areas on dyeing with Lugol solution. Histologically, all 17 lesions were squamous cell carcinomas; 10 lesions being mucosal carcinomas, the remaining 7 lesions mucosal carcinomas spreading beyond the epithelial layer. The lesions ranged from 0.7 to 4.0 cm in size. Abnormal findings were noted under conventional endoscopy in all but 3 lesions diagnosed only by postoperative pathohistology, regardless of the size and depth of the invasion. Under conventional endoscopy, the following types of morphological changes were noted in 8 (57.1%) of the 14 lesions: slight elevation (1 lesion), depression (6 lesions), and deformed arc (1 lesion). A color change was noted endoscopically in 12 of the 14 lesions (85.7%), this change being redness in all 12 lesions. The unstained area on the resected specimen was consistent with the size of the lesion that was determined by using serially sectioned blocks in all cases. Moreover, the former completely (100%) coincided with the histological area where PAS reaction was weak. In conclusion, under conventional endoscopy, a color change such as redness is an important indicator of minute or superficial esophageal cancer, as is such morphological change as depression, elevation or deformed arc. On the other hand, Lugol dye endoscopy is very helpful in detecting esophageal cancer unassociated with any morphological or color change. It also provides accurate information about the extent of the cancer.

Aged↗
PubMed1990

Interaction of gramicidin S analogs with lipid bilayer membrane.

One of the side chains of Orn residues in gramicidin S (GS) was connected with alanine (AGS), sarcosine (SGS), or histidine (HGS) residue, aiming at developing membrane-active artificial enzymes by virtue of the membrane-associating property of GS. The conformation of the GS analogs was similar to that of GS. However, the affinity of GS and its analogs for dipalmitoylphosphatidylcholine (DPPC) vesicles decreased in the order of GS greater than SGS greater than HGS congruent to AGS. The addition of GS analogs at 10 microM to DPPC vesicles decreased the membrane fluidity, indicating that GS analogs did not disrupt the vesicular structure of DPPC vesicles. On the other hand, GS analogs enhanced carboxyfluorescein-leakage from DPPC vesicles. It was therefore considered that the GS analogs induced the phase-separation of the lipid bilayer membrane. Hydrolytic reactions of HGS in the presence of DPPC vesicles were studied using N-methylindoxyl alkanoate as substrate. HGS reacted only with N-methylindoxyl hexanoate below the phase-transition temperature of the membrane. The substrate specificity of HGS was ascribed to the condensation of HGS in the neighbourhood of the substrate in the lipid bilayer membrane due to the phase-separation below the phase-transition temperature of the membrane.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1990

Changes in alpha-tubulin and actin gene expression during optic nerve regeneration in frog retina.

The optic nerve of the bullfrog was transected and the regeneration process was investigated. We previously reported that alpha-tubulin mRNA in the retina increased to a maximum 1-2 h after optic nerve transection with no specific change in actin mRNA. In the present investigation, we examined the long-term effect of optic nerve transection. Northern blot analysis revealed that alpha-tubulin mRNA increased again gradually after the rapid and transient increase and actin mRNA increased to a maximum at 7 days (more than twofold compared to the control retinas). The period during which actin mRNA reaches a maximal increase almost corresponds to the time lag between the axotomy and the initiation of axonal outgrowth. The main cytoskeletons of neuronal growth cones have been shown to consist of actin-containing microfilaments. Therefore, the transient increase of actin mRNA may have a relationship to the initial outgrowth of axons. On the other hand, the rapid and transient increase of alpha-tubulin mRNA observed in our previous studies is probably one of the initial responses of retinal ganglion cells to the axotomy, and the gradual increase in alpha-tubulin mRNA observed in this study can probably be interpreted as provision of the structural materials necessary for axonal elongation.

Actins↗
PubMed1990

Autoantibodies to keratin in Sjögren's syndrome.

In order to determine which components of the salivary duct cells are recognized by the antisalivary duct antibodies, sera of patients with Sjögren's syndrome were screened for immunoreactivity to keratin by using an ELISA test and a Western blot analysis. The autoantibodies which reacted with keratin were demonstrated in 8 of 9 definite cases of Sjögren's syndrome and in 3 of 6 probable cases, and they reacted with different keratin peptides in each case. The results suggest that the antisalivary duct antibodies include antibodies against keratin, which exists ubiquitously as a cytoskeleton in the salivary gland epithelial cells. Detection of antikeratin antibody might be a useful aid for diagnosis of Sjögren's syndrome.

Adult↗
PubMed1990

Evaluation of two monkey species (Macaca mulatta and Macaca fascicularis) as possible models for human Helicobacter pylori disease.

Endoscopic, histologic, and microbiologic evaluations of 21 cynomolgus and 34 rhesus monkeys for naturally occurring Helicobacter pylori infection were done. H. pylori was never isolated from any cynomolgus monkey, but was found in 12 rhesus monkeys. A general correlation existed between a positive culture and a gastric inflammatory response. Inoculation challenges were then undertaken. Four cynomolgus and five rhesus monkeys received two different H. pylori strains isolated from humans. Five rhesus monkeys received an isolate obtained from rhesus monkeys. Evaluation of the cynomolgus monkeys 7 and 14 days later revealed no H. pylori. Endoscopies of the rhesus monkeys were done 7, 14, 21, 28, and 56 days later. One rhesus monkey, which received the isolate from humans, became H. pylori positive at day 21 and remained positive through day 56. Restriction enzyme analysis of genomic DNA at day 56 revealed that the isolate was not identical to the challenge strain isolated from humans. All five rhesus monkeys that received the strain isolated from rhesus monkeys became H. pylori positive by day 14 and remained positive through day 56 Antral inflammation developed in all monkeys. Restriction enzyme analysis of genomic DNA on day 56 confirmed that four of five isolates were identical to the challenge strain isolated from rhesus monkeys. DNA hybridization documented homology between the challenge strains isolated from humans and rhesus monkeys plus those isolated at day 56. In this study, we showed that the rhesus monkey, if given a strain of H. pylori isolated from rhesus monkeys, develops a gastric infection with accompanying histological changes, making this model suitable for further development.

Animals↗
PubMed1990

[Evaluation of the treatment results of anterior crossbite in the mixed dentition].

As an evaluation of treatment for anterior crossbite (Class I Malocclusion) in the mixed dentition, relationships were examined between the results of cluster analysis on the measured values before treatment and those on the changes caused by treatment. The following were the results of the present investigation. 1. The results of cluster analysis on the measured values before treatment were summed up into three groups; A1, A2, and A3. 1) Group A1 showing retrusion of the Maxilla and lingual version and lingual inclination of Maxillary anterior teeth. 2) Group A2 showing protrusion of the Mandible, lingual version of Maxillary anterior teeth, and lingual inclination of Mandibular anterior teeth. 3) Group A3 showing lingual version of Maxillary anterior teeth and labial version of Mandibular anterior teeth. 2. The results of cluster analysis on the changes caused by treatment were classified into three groups; V1, V2, and V3. 1) Group V1 showing labial version and labial inclination of Maxillary anterior teeth and lingual version and lingual inclination of Mandibular anterior teeth. 2) Group V2 showing protrusion of the Maxilla, labial version of Maxillary anterior teeth, and lingual version and lingual inclination of Mandibular anterior teeth. 3) Group V3 showing retrusion of the Mandible and labial version and labial inclination of Maxillary anterior teeth. 3. Relationships between Groups A1, A2, and A3 and those of V1, V2, and V3 may be summarized in the following. 1) Group A1 shows healing trend of Group V2. 2) Group A2 shows healing trend of either Group V1 or Group V3. 3) Group A3 shows healing trend of Group V1. The results shown above indicate that healing process is dependent upon many factors including a problem of mixed dentition, a problem of constructing dental arch and individual growth characteristics. Therefore, it is important for us to recognize the findings described above when treating anterior crossbite in the mixed dentition.

Cephalometry↗
PubMed1990

[Surgical salvage of cardiac rupture: a case report].

A 39-year-old man suffered from acute myocardial infarction. Echo cardiography showed the presence of intra-pericardial fluid. We had emergent operation. We successfully salvaged cardiac rupture with fibrin glue and oxy-cellulose without cardiopulmonary bypass. His post-operative course was uneventful. The patient was discharged on the seventh week after the operation. The problems of acute cardiac rupture were discussed.

Adult↗
PubMed1990

[Role of systemic and pulmonary hemodynamics in genesis pleural effusion in congestive heart failure].

We tried to make an estimate of how pleural effusion occur in congestive heart failure, using right atrial pressure (RA) and pulmonary arterial wedge pressure (PAW) as variables. We calculated the following equation by quoting the data in the past. RA greater than -0.02 x PAW + 13.3. We speculated that when this relationship is satisfied, pleural effusion will appear. We also studied the patients with severe congestive heart failure, dividing them into 2 groups, ie the pleural effusion group (EF) and pulmonary edema group (ED). Compared with ED, EF has a significantly higher RA (RA = 6.1 +/- 1.33 mmHg in EF and 13.3 +/- 2.21 mmHg in ED, mean +/- SE, p less than 0.02) and a significantly lower cardiac index (3.17 +/- 0.26 l/min/m2 vs 2.23 +/- 0.16 l/min/m2, mean +/- SE, p less than 0.01). Therefore, we thought that it was adequate to treat RA and PAW as independent variables. These equations appear to be useful in predicting the development of pleural effusion that's based in the plots of our patients on RA-PAW plane and their relationship to our equations.

Aged↗
PubMed1990

[Laser ablation in the treatment of ventricular tachycardia: problems in the clinical case].

I. Experimental Studies We examined if laser ablation could make the same characteristic lesion as cryolesion to canine myocardium. Nine mongrel dogs were used in this experiment. Right lateral thoracotomy was performed and Nd:YAG laser was delivered onto the epicardial surface of both ventricles. Laser power of between 10 and 50 W was used with the various duration of 3 and 20 s, keeping the lasing distance 5 mm above the cardiac surface. Histologically, the lesion showed a well-demarcated area consisted of coagulation necrosis and contraction band necrosis in the acute phase, which changed to a fibrous scar in the chronic phase. There was a good correlation (r = 0.79; n = 52, p less than 0.01) between the lasing energy and the depth of the denaturation zone. II. A Case Report A 45-year-old male with ventricular tachycardia (VT) after aortic valve replacement was operated upon with Nd; YAG laser delivery. An antero-lateral thoracotomy through 4th and 6th inter-costal space was performed. The intraoperative mapping showed the three origins of VTs to be near the apex of left ventricle. With cardiopulmonary bypass, Nd; YAG laser was delivered onto the endocardial surface adjacent to arrhythmogenic foci. The lasing power was 10-30 W with the duration of 5.0-9.9 s. One hundred twenty seven trials were done with the total lasing energy to be 12490 J. Subsequently cryoablation was added on this area. Though VT remained in acute phase, 2 weeks later, all of tachyarrhythmia was abolished spontaneously.

Animals↗
PubMed1990

[Technical considerations for the epicardial approach in Wolff-Parkinson-White syndrome].

Epicardial approach consists of meticulous dissection of the annular fat pad of the Kent bundle site and subsequent cryocoagulation from the epicardial side. This technique obviates the need of atriotomy and makes ablation without cardiopulmonary bypass possible. In performing this approach for patients with the left parietal or posteroseptal pathway through median sternotomy, special technical strategies are necessary to keep hemodynamic status stable during dissection and cryoablation procedures, because in these cases apex of the heart has to be retracted upward to approach the Kent bundle site. For this purpose, the use of an ultrasonic surgical aspirator for dissection of the annular fat pad is required. With this instrument fat tissue is emulsified and aspirated by stroking the fat pad gently, easy dissection is possible without injury to major coronary vessels, even through a narrow operative field. Another point is to dissect the annulus fat below the coronary sinus (i.e., at the space between the coronary sinus and circumflex coronary artery), not above it. By doing this extensive retraction of the apex is no longer necessary. In performing cryocoagulation care has to be taken not to involve the coronary artery into the lesion. However, too tight retraction of the coronary artery may cause another risk of thrombosis. Sometimes moderate systemic heparinization should be performed during coronary retraction and cryocoagulation procedure.

Heart Conduction System↗
PubMed1989

Hydrolytic reaction catalyzed by poly[N-(substituted)glycine]s having imidazolyl groups in side chains in the presence of liposome.

Hydrolytic reactions in the presence of liposomes catalyzed by N epsilon-benzyloxycarbonylhistidine groups introduced into the side chains of poly[N-(3-aminopropyl)glycine] were studied. On increasing the hydrophobicity of the polypeptide catalyst by introducing dodecyl groups into the side chains, and in the presence of dipalmitoylphosphatidylcholine (DPPC) bilayer membranes, p-nitrophenyl palmitate (PNPP) was hydrolyzed more rapidly than p-nitrophenyl acetate (PNPA). The addition of cholesterol or phosphatidylserine to lipid bilayer membranes accelerated the hydrolysis of PNPP catalyzed by the polypeptide catalyst more strongly than that of PNPA. The substrate selectivity and catalytic efficiency of the polypeptide catalyst were found to be controlled by the physical state of the lipid bilayer membranes.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1989

Postoperative results of distal partial gastrectomy, selective vagotomy plus antrectomy, and selective proximal vagotomy for duodenal ulcers.

We investigated the postoperative results of distal partial gastrectomy, selective vagotomy plus antrectomy, and selective proximal vagotomy, to evaluate their effectiveness in the treatment of duodenal ulcers. The operative mortality of selective vagotomy plus antrectomy and selective proximal vagotomy seemed to be lower when compared to distal partial gastrectomy, although each procedure showed a sufficiently low mortality. The acid reduction rate was significantly lower after selective proximal vagotomy than after the other procedures (p less than 0.01). However, the rate of ulcer recurrence following selective proximal vagotomy tended to be higher compared with the other procedures. All three procedures showed good results according to Visick's grading and postoperative symptoms occurred in about 50 per cent of all patients, no matter what the procedure. The regaining of physical ability was significantly greater following selective proximal vagotomy than following distal partial gastrectomy (p less than 0.05) and the capacity to work was also better after vagotomy, particularly selective vagotomy plus antrectomy (p less than 0.05). Thus, although distal partial gastrectomy and selective vagotomy plus antrectomy proved superior regarding the low ulcer recurrence rate and acid reduction, while selective proximal vagotomy proved superior for improving the quality of life, on the whole, the three operations promise almost equivalent results.

Adult↗
PubMed1989

Cryosurgical ablation of accessory atrioventricular pathways without cardiopulmonary bypass: an epicardial approach for Wolff-Parkinson-White syndrome.

An epicardial approach has been developed and applied to 31 Kent bundles (23 parietal, 1 right anteroseptal, and 7 posteroseptal bundles) in 28 patients with Wolff-Parkinson-White syndrome. Our technique consists of dissection of the atrioventricular fat pad of the Kent bundle site using an ultrasonic aspirator and subsequent cryosurgical ablation. For the left parietal and posteroseptal pathways, the apex of the heart has to be retracted upward, but this maneuver was well tolerated in all patients. Moreover, even through a narrow operative field, the ultrasonic aspirator permitted deliberate dissection on the beating heart without injury to major coronary vessels or the atrial wall. In 89% of the patients, operation was performed without the use of heart-lung bypass. All patients were free from preexcitation. With this technique, all Kent bundles except that adjacent to the atrioventricular node can be ablated on the beating heart, usually without heart-lung bypass.

Adolescent↗
PubMed1989

Early diagnosis of esophageal cancer. Analysis of 11 cases of esophageal mucosal cancer.

We reviewed 11 patients with esophageal mucosal carcinoma in various aspects to improve the early diagnosis of the disease. Eighteen lesions measuring 0.5 to 5.0 cm were confirmed histologically in the 11 cases. Histologically 10 of the 18 lesions were carcinomas in situ (ep cancer), and the other 8 lesions were carcinomas confined to the mucosa other than ep cancer (mm cancer); all 18 lesions were squamous cell carcinomas. Six (85.7%) of the seven mm cancers showed abnormal radiographic findings regardless of the size. Similarly these findings were noted on four of five (80%) ep carcinomas 2 cm or larger in size. All 15 lesions diagnosed before operation showed abnormal findings on conventional endoscopy regardless of the size and depth of transmural invasion. Morphologic change was observed in 9 lesions (53.3%), while 13 (86.7%) showed color change; most of the lesions (80%) were manifested as redness. Dyeing of the resected specimen with Lugol solution (Katayama Chemical Industries, Osaka, Japan) showed all 18 cancerous lesions as unstained areas. Among the 18 lesions, two lesions were unstained areas, which agreed with the areas determined histologically. An additional lesion was visible with dye endoscopy as an unstained area but it was not visible with radiography or conventional endoscopy. Dye endoscopy using Lugol solution is very important because it allows detection and evaluation of the extent of esophageal mucosal cancer.

Aged↗
PubMed1989

Predictability of left heart dysfunction from right heart performance--cardiac index-venous pressure plots and cardiac index-mean pulmonary artery wedge pressure plots at rest and their shift during dynamic exercise.

In an attempt to examine the extent to which the right heart performance can predict the left heart performance in heart diseases primarily affecting the left heart, we recorded cardiac index-venous pressure (CI-VP) plot and cardiac index-mean pulmonary artery wedge pressure (CI-PAW) plot at rest and investigated the shift of CI-VP plot and CI-PAW plot that occurred during mild dynamic exercise of the lower limbs. Six patients had normal heart function and 20 patients had heart diseases primarily affecting the left heart. The sensitivity, specificity, positive predictive value and negative predictive value in the estimation of the left heart function with delta CI/delta VP were 80%, 100%, 89% and 100%, respectively, when delta CI/delta PAW was regarded as the golden standard for the estimation of the left heart function. The sensitivity, specificity, positive predictive value and negative predictive value in estimating the left heart function with delta CI/delta RA were 86%, 93%, 92% and 86%, respectively. When the left heart function was estimated by delta VP alone without measuring delta CI, the sensitivity, specificity positive predictive value and negative predictive value were 40%, 100%, 73% and 100%, respectively. In short, it was possible to predict the left heart dysfunction with delta CI/delta VP or delta CI/delta RA, in the presence of the right heart dysfunction. It was also possible to predict a steep heart slope from normal delta CI/delta VP with error of 2/18 (11%), when steep left heart slope was predicted, based on the presence of steep right heart slope. In comparison, delta VP alone was a less sensitive index of the performance of the left heart.

Adolescent↗
PubMed1989

Quantitative estimation of compliance of human systemic veins by occlusion plethysmography with radionuclide--methodology and the effect of nitroglycerin.

Volume-pressure relationship and compliance of human systemic veins were estimated quantitatively and noninvasively using radionuclide. The effect of nitroglycerin (NTG) on these parameters was examined. Plethysmography with radionuclide (RN) was performed using the occlusion method on the forearm in 56 patients with various cardiac diseases after RN angiocardiography with 99mTc-RBC. The RN counts-venous pressure curve was constructed from (1) the changes in radioactivity from region of interest on the forearm that were considered to reflect the changes in the blood volume of the forearm, and (2) the changes in the pressure of the forearm vein (fv) due to venous occlusion. The specific compliance of the forearm veins (Csp.fv; (1/V).(delta V/delta P] was obtained graphically from this curve at each patient's venous pressure (Pv). Csp.fv was 0.044 +/- 0.012 mmHg-1 in class I (mean +/- SD; n = 13), 0.033 +/- 0.007 mmHg-1 in class II (n = 30), and 0.019 +/- 0.007 mmHg-1 in class III (n = 13), of the previous NYHA classification of work tolerance. There were significant differences in Csp.fv among the three classes. The systemic venous blood volume (Vsv) was determined by subtracting the central blood volume, measured by RN-angiocardiography, from total blood volume, measured by the indicator dilution method utilizing 131I-human serum albumin. Systemic venous compliance (Csv) was calculated from Csv = Csp.fv.Vsv. The Csv was 127.2 +/- 24.8 ml.mmHg-1 (mean +/- SD) in class I, 101.1 +/- 24.1 ml.mmHg-1 in class II and 62.2 +/- 28.1 ml.mmHg-1 in class III. There were significant differences in Csv among the three classes. The class I Csv value was calculated to be 127.2 +/- 24.8 ml.mmHg-1 and the Csv/body weight was calculated to be 2.3 +/- 0.7 ml.mmHg-1.kg-1 of body weight, which was very close to the values for Csv reported previously by other investigators in animal experiments. The administration of NTG caused the RN counts - venous pressure curve to become steeper and shift upward. It increased Csv significantly in all cases.

Adult↗
PubMed1989

Oxidation of atmospheric molecular tritium in plant leaves, lichens and mosses.

The oxidation of atmospheric molecular tritium (HT) in vegetation was determined by in vitro experiments for pine needles, pine bark, lichens attached to pine trees, taken from a coastal pine forest in Ibaraki prefecture and comparison of such measurements was made with those in soil. The oxidation of HT in pine needles was extremely low, being only about 1/40000 that in the surface soil of a pine forest, whereas its oxidation in pine bark with a lichen was almost 1000-7000 times higher than that in pine needles. HT oxidation in pine bark, a lichen and a moss was determined in each case under light and dark conditions and was found to be essentially the same. All mosses and lichens examined in the present study were found to have unusually high levels of HT oxidation whether their habitat was tree or ground surface.

Atmosphere↗