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Biomedical subjects

Y Tamiya

Publications and source records attributed to Y Tamiya.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Operative results and long-term prognosis of type A acute aortic dissection].

Between 1983 and 1997, we operated upon 91 patients with type A acute aortic dissection. The dissection was localized in 22 patients and extensive in 69 patients. All patients underwent graft replacement and 61 (67%) patients underwent simultaneous replacement of ascending aorta and total aortic arch. The hospital mortality rate were 9% for the localized dissection and 21% for the extensive dissection. The actuarial survival rates in patients with localized dissection at 5 and at 10 years was 91% and 76%, whereas those in patients with extensive dissection at 5 and at 10 years was 68% and 62%. The freedom from dissection related death or reoperation in operative survivors with localized dissection at 5 and at 10 years was 100% and 83%, whereas those in patients with extensive dissection at 5 and at 10 years was 78% and 56%. The simultaneous replacement of ascending aorta and total aortic arch in patients with extensive dissection was effective to obliteration of the distal false channel, although this extended procedure has to be carefully adopted in high risk patients with associated complications such as acute dissection organ ischemia.

Acute Disease↗
PubMed1997

Absence of RET proto-oncogene mutations in a father and son with pheochromocytoma and pancreatic islet cell tumor.

BACKGROUND: We describe a father and son with a combination of pheochromocytoma and pancreatic islet cell tumor. Although its familial occurrence is rare, this syndrome could be called overlapping-type multiple endocrine neoplasia (MEN), since it fulfills the criteria for both type 1 and type 2 MEN. Recently, germ line mutations of the RET proto-oncogene (RET) were found to be related to tumorigenesis and disease phenotypes in type 2 MEN. METHODS: Using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis, we looked for germ line mutations of RET in 8 members of this family, including the 2 patients. RESULTS: Analysis of RET exons 10, 11 and 16, which contain the hot-spot codons for MEN type 2, revealed no mutations in any individual examined. CONCLUSION: These findings suggest that these 3 exons in RET are not related to tumorigenesis in overlapping-type MEN.

Adenoma, Islet Cell↗
PubMed1997

[A case report of ruptured distal aortic arch aneurysm into pericardial space].

We report a case of successful total aortic arch replacement using selected cerebral perfusion for ruptured distal aortic arch aneurysm (DAAA) into the pericardial space. A 75 year-old man who had preoperative episode of severe chest pain and tachycardia was transferred to our hospital. Computed tomography showed saccular DAAA and pericardial effusion, so the patient was diagnosed as ruptured DAAA into pericardial space. Immediately after CT-scanning, urgent operation of a graft replacement of aortic arch with selective cerebral perfusion was carried out. Postoperatively, he had no cerebral complication, but develop transient respiratory failure and renal dysfunction. Three months after the operation he was discharged from the hospital. The patient is now leading a normal life.

Aged↗
PubMed1997

[Extended total aortic arch replacement involving the proximal descending aorta through a median sternotomy].

From January 1986 to September 1995, total aortic arch replacement (TAR) for aortic dissection was performed using selective cerebral perfusion in 151 patients. In 18 patients, the surgical procedures of extended aortic arch replacement (EAR) involving the proximal descending aorta through a median sternotomy were applied. To evaluate the outcome of EAR, the early and late results were compared with those of non-extended aortic arch replacements (NAR) through a median sternotomy (n = 66). The early mortality rates for EAR and NAR were 5.6% and 16.7%, respectively (NS); the lower rate for EAR may be due to the fact that EAR were performed more recently than NAR. The differences between EAR and NAR with respect to the amount of blood transfused intraoperatively and the respiratory index at 12 hours after surgery were not statistically significant. In addition, the extracorporeal bypass time in EAR was no longer than that in NAR. Thus, as compared with the NAR procedure, the EAR procedure did not have a negative effect on early outcome. Regarding late results, the actuarial survival rates after EAR and NAR, respectively were 87% and 72% at 1 year, 87% and 69% at 3 years (NS). The early thrombo-occlusion rates of the remaining false lumens after TAR in broad aortic dissections were 56% after EAR and 33% after NAR (p = 0.21). These results suggest that EAR may be a more useful procedure in some patients requiring TAR.

Aged↗
PubMed1997

[Surgical strategy for Stanford type A aortic dissection with Marfan syndrome].

Between January 1979 and May 1996, 23 Marfan patients underwent surgeries for type A aortic dissection; 8 patients with localized type dissection and 15 with extensive type. All of the 23 patients suffered from annuloaortic ectasia (AAE) which was treated by composite graft replacement, 10 of these patients had a concomitant replacement of the aortic arch. The operative mortality rate was 8.7%, and the causes were associated with the methods of coronary artery reattachment to the graft. Of the 15 patients with the extensive type dissection, there were 11 patients who had a non-thrombotic communicating false lumen in the untreated segments of the distal dissected aorta after the first operation and from this group there were seven patients who had anastomotic leakage around the distal suture line of the graft replacement that was demonstrated by aortography. Extensive graft replacement ranging from the entire thoracic aorta to the total aorta were performed in 10 (43.5%). Late deaths occurred in three patients (13.0%) and these causes were LOS and graft infection after the second operation and prosthetic valve endcarditis 6 months after the first operation. The present data indicate that Stanford type A aortic dissection with Marfan syndrome should be undertaken on the basis of a prior achievable plan to perform an entire aortic replacement. The dissection should also be performed using a procedure which doesn't leave distal anastomotic leakage.

Adolescent↗
PubMed1996

Extended aortic replacement for acute type A dissection with the tear in the descending aorta.

OBJECTIVE: There has been controversy as to the selection of surgical treatments for acute type A dissection with the tear in the descending thoracic aorta, a subtype of acute aortic dissection in which the limited tear is located distal to the left subclavian artery but the dissection extends retrogradely to the ascending aorta. METHODS: Total replacement of the ascending aorta and aortic arch was performed in 12 patients with acute type A dissection with the tear in the descending thoracic aorta between March 1991 and the end of September 1995. The indications for total replacement of the ascending aorta and aortic arch were cardiac tamponade, acute aortic regurgitation, cerebral ischemia, and dilatation of the ascending aorta. The operation was performed with the aid of extracorporeal circulation, blood cardioplegia, selective cerebral perfusion, and open distal anastomosis. The surgical procedure used was total replacement of the ascending aorta and aortic arch with a graft provided with three limbs accompanied by resection of the intimal tear in the descending thoracic aorta. RESULTS: Hospital death occurred in two patients (16.7%). In both, death was due to dissection/related complications of renal/mesenteric ischemia. The other 10 patients have had uneventful postoperative courses over a mean period of 24 months. CONCLUSIONS: Total replacement of the ascending aorta and aortic arch accompanied by resection of an intimal tear distal to the left subclavian artery seems to be justified in selected patients with acute type A dissection with the tear in the descending thoracic aorta.

Acute Disease↗
PubMed1995

Electrogastrography prior to and following total gastrectomy, subtotal gastrectomy, and gastric tube formation.

On electrogastrography (EGG) spectral analysis, an activity of 3 cycles per minute (cpm) is supposed to be specific for the stomach. After total or subtotal gastrectomy, the original site of the stomach is occupied mainly by the intestine. We attempted to determine if intestinal activity could be recorded in this region with EGG. Epigastric recordings were performed in patients prior and following gastrointestinal or control surgeries. Spectral analysis, using the maximal entropy method and ensemble means was applied to data analysis from these recordings. Preoperatively, the majority of the power peaks were found around 3, 6, and 11 cpm. The postprandial-to-fasting power ratio of all of these power peaks increased significantly postprandially (P < 0.05-0.01). Following total gastrectomy, the power peak around 3 cpm disappeared or was significantly diminished in amplitude (P < 0.05). The postoperative-to-preoperative power ratio ranged from 0.03 to 0.10 (P < 0.001-0.01). However, the power peak around 11 cpm did not significantly change prior to or following total gastrectomy, and the 11 cpm peak appeared relatively dominant. Simultaneous manometric studies in the Roux limb demonstrated a correlation between the power spectral frequency of EGG and manometry at 11 cpm. Therefore, the 11 cpm peak appeared to reflect jejunal or Roux limb electrical activity. The postoperative to preoperative power ratio for the 3 cpm also was significantly reduced following subtotal gastrectomy and gastric tube formation in patients in the postprandial state (P < 0.05-0.001).

Adult↗
PubMed1995

Protective effect of monoclonal antibodies against LFA-1 and ICAM-1 on myocardial reperfusion injury following global ischemia in rat hearts.

The effects of anti-LFA-1 and anti-ICAM-1 monoclonal antibodies (MAbs) on the reperfusion injury of rat cardiac tissues after global ischemia were studied. Studies were performed using an isolated blood perfused heart preparation in which hearts were subjected to 30 min of global ischemia followed by 40 min of reperfusion. Isolated rat hearts were perfused with blood from an anesthetized support rat with or without anti-LFA-1 or anti-ICAM-1 monoclonal antibody administration (n = 10 in each group). Ventricular function, myocardial tissue water content and myocardial energy status were evaluated in this model. In the control group, ischemia and reperfusion of isolated hearts resulted in a 63.6 +/- 2.7% recovery of left ventricular developed pressure (LVDP) and a 44 +/- 7% increase in coronary vascular resistance compared with pre-ischemic baseline values. Treatment with anti-LFA-1 MAb or anti-ICAM-1 MAb resulted in a 77.2 +/- 1.5% and a 80.4 +/- 3.0% recovery of LVDP, respectively. In addition, increase in coronary vascular resistance was only 23 +/- 7% and 13 +/- 6% in anti-LFA-1 and anti-ICAM-1-treated groups, respectively. Values are significantly different between the control group and MAb-treated groups. Ischemia and reperfusion resulted in a 16% increase of myocardial tissue water content (3.71 +/- 0.03 in pre-ischemic baseline versus 4.29 +/- 0.08 ml/g dry weight) in the control group, whereas that resulted in only 3.0 and 5.7% increase in anti-LFA and anti-ICAM-1-treated groups, respectively. The difference between the control group and MAb-treated groups was significant. Cardiac energy status as assessed by adenosine triphosphate (ATP) concentration was markedly reduced in the control group at 40 min of reperfusion compared with pre-ischemic baseline values (5.70 +/- 0.27 vs. 14.92 +/- 0.48 mumol/g dry weight). In contrast, the reduction of myocardial ATP concentration at 40 min of reperfusion was significantly inhibited by anti-LFA-1 and anti-ICAM-1 monoclonal antibody treatment (5.70 +/- 0.27 vs. 8.96 +/- 0.52 and 8.10 +/- 0.47 mumol/g dry weight, respectively). These results suggest that a LFA-1/ICAM-1 pathway plays a critical role in the pathogenesis of postischemic myocardial injury during early reperfusion period.

Animals↗
PubMed1994

[Hand eczema. The clinical classification of the roles of exogenous and endogenous factors in each type].

Hand eczema is one of the most common dermatological disorders. Although it is a general term referring to eczematous dermatitis of the hands, it actually covers a wide range of diseases. The classification of hand eczema is controversial even now, as definitions of individual diseases have not yet been established. It is well-known that exogenous factors, such as chemicals or water, are associated with the occurrence of hand eczema. In this study, we focused on endogenous factors, especially personal or family history of atopy as a causative factor in hand eczema. According to exogenous and endogenous factors, we classified hand eczema into three types: atopic dermatitis, contact dermatitis and dysidrosis. This classification is useful because it makes the definition of each disease clear. Skin-humidity and sebum measurement are simple and rapid methods of determining personal atopy, skin condition and the effect of treatment on hand eczema patients.

Adult↗
PubMed1991

The effects of temperature on the setting of glass ionomer (polyalkenoate) cements.

Glass ionomer (polyalkenoate) cements have proved to be superior to zinc phosphate cements as orthodontic luting agents. Setting behaviours at different temperatures were recorded by an oscillating rheometer under controlled conditions. The working time of these cements can be increased by mixing on a chilled glass slab with setting time at mouth temperatures remaining rapid. Where more than one orthodontic band is cemented per mix, the authors recommend refrigeration of the glass slab for at least one hour prior to mixing the cement.

Dental Bonding↗
PubMed1989

[Quantitative analysis of myocardial revascularization on left ventricular diastolic function].

To evaluate the effects of myocardial revascularization on left ventricular diastolic function, we studied three groups of subjects. Group I consisted of 10 patients without any previous myocardial infarction. Group II consisted of 10 patients with previous myocardial infarction. The control group consisted of 8 normal subjects, all with no evidence of cardiac disease as determined by cardiac catheterization. Left ventricular diastolic function was assessed by maximum negative dp/dt, constant T, diastolic compliance and 1/3 fractional filling before and after surgical revascularization. (1) Constant T, maximum negative dp/dt and diastolic compliance: There was no significant difference among groups I, II and the control group preoperatively, and the variables were not improved postoperatively. (2) 1/3 fractional filling: 1/3 fractional fillings in groups I and II were significantly lower (p less than 0.05, p less than 0.01) than the control group preoperatively, and it was significantly improved in group I, but unchanged in group II postoperatively. In conclusion, myocardial revascularization improves left ventricular diastolic function in the patients without previous myocardial infarction. The effects of myocardial revascularization, however, in the patients with prior myocardial infarction do not bring about an enhancement of left ventricular diastolic function.

Adult↗
PubMed1987

Blood type compatibility of lower vertebrates: phylogenetic diversity in blood transfusion between fish species.

Bidirectional transfusion was investigated using phylogenetically different fish species, including twelve from ten genera. Three different modalities were used: long-lasting persistence when rainbow trout received allogenic erythrocytes, slow rejection when rainbow trout received heterogenic erythrocytes (salmon) and acute rejection after receiving xenogenic erythrocytes (goldfish, carp and Tilapia). Changes were measured in serum using transfused erythrocytes and hemolytic assays. The responses were species specific for large taxonomic fish groups characteristic of their phylogenetic interrelations. Findings concerning the evolution of compatibility of fish blood types, in view of the taxonomy and phylogeny of vertebrates, are interesting since phylogenetic diversity in transfusion demonstrates that erythrocyte types and serum types exist even in lower vertebrates.

Animals↗