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Biomedical subjects

S Aoyagi

Publications and source records attributed to S Aoyagi.

At least 181 records · Page 10Linked to original sources

Aortic dissection after aortic valve replacement. Report of a case with an aortocameral fistula.

A 58-year-old Japanese woman who had a history of aortic valve replacement for congenital bicuspid valve, was admitted for investigation of facial edema and of pulselessness of the right leg. Physical examination disclosed the patient suffering from a superior vena cava syndrome. On auscultation, a continuous murmur was heard at the left lower sternal border. Computed tomographic scans revealed aortic dissection extending from the ascending aorta to the bifurcation. Echocardiography showed an intimal flap in the dilated ascending aorta, but not abnormal blood flow from the aorta to the right atrium was detected. Cardiac catheterization and aortography, however, allowed a correct diagnosis of aortic dissection with fistula to the right atrium and with obstruction of the right common iliac artery. The patient received emergency aortic root replacement and reconstruction of the coronary arteries and then recovered uneventfully.

Aortic Dissection↗

Total aortic replacement in a patient with mega aorta syndrome--a case report.

A 64-year-old woman without manifestations of Marfan syndrome was referred for the close investigation of a pulsatile abdominal mass. Computed tomographic scans and magnetic resonance images revealed aneurysmal dilatation of the entire aorta, including the ascending aorta and extending to the bifurcation of the aorta, as well as tortuousness of the thoracoabdominal and abdominal aorta. Digital subtraction angiography also showed aneurysmal dilatation of the entire aorta and trivial aortic regurgitation. However, aortic annular dilatation was not found by echocardiography or aortography. The entire aorta was replaced in two stages. First, graft replacement of the ascending aorta, except for the sinus segment, and the aortic arch was performed using an elephant trunk technique under hypothermic cardiopulmonary bypass with selective cerebral perfusion. Twelve weeks later, the remaining aorta, including the descending aorta and extending to the common iliac artery on the right side, and to the common femoral artery on the left side, was replaced with a partial cardiopulmonary bypass using femoral artery and vein cannulation. We believe that patients with mega aorta syndrome are best treated by total aortic replacement. The results in the present case indicate that the elephant trunk technique is useful for extensive aortic replacement in stages, and greatly facilitates the second stage operative procedures.

Aorta↗

Estimates of zinc and iron bioavailability in pork liver and the effect of sex of pig on the bioavailability of copper in pork liver fed to male and female chicks.

Four chick experiments were conducted to investigate possible explanations for why Cu bioavailability in pork liver is zero. One possible explanation was that pork liver contains compounds, such as Zn, that directly or indirectly inhibit Cu utilization. It has also been suggested that sex differences may influence Cu bioavailability. The effect of freeze-dried (FD) pork liver from gilts vs barrows was first examined. Neither FD gilt liver nor FD barrow liver provided any bioavailable Cu to chicks. The effect of sex of the chicks used in the assay (i.e., male chicks vs female chicks) was also examined, but there were no sex-dependent differences (P > .10) in the slopes of the standard curve generated by added Cu from CuSO4 or in the responses to added FD pork liver. Based on bone Zn uptake, Zn bioavailability in FD barrow liver and FD gilt liver was not different (P > .04) from that in ZnSO4, but Fe bioavailability (hemoglobin repletion assay) was approximately 40% (P < .05) of that in FeSO4 in both FD gilt liver and FD barrow liver.

Animal Feed↗

Copper bioavailability in pork liver and in various animal by-products as determined by chick bioassay.

Three chick experiments were conducted to investigate possible explanations for why pork liver provides no bioavailable Cu to chicks. Autoclaving, acid-hydrolysis, and protease-digestion increased (P < .01) Cu bioavailability in pork liver to 32, 46, and 63%, respectively, from virtually 0% of the Cu in unprocessed pork liver (relative to CuSO4, which was set at 100%). Addition of EDTA at 200 mg/kg to the diet containing 1 mg of Cu/kg from unprocessed pork liver also resulted in an increased (P < .07) Cu bioavailability, to 23%. Tissues representing different sources of endogenous Cu in the pig also were evaluated for their Cu bioefficacy. Freeze-dried (FD) porcine bile did not have any bioavailable Cu, whereas spray-dried porcine plasma contained Cu that was as available (99%) as that in CuSO4. In addition, when FD pork liver or FD porcine bile was added to the basal diet containing .5 mg of Cu/kg from CuSO4, Cu bioavailability in CuSO4 was reduced (P < .05) to 34% and 19%, respectively, of values obtained with CuSO4 alone. An additional experiment was conducted to estimate Cu bioefficacy in selected animal-source feed ingredients. Copper bioavailability in all-beef meat and bone meal, all-pork meat and bone meal, mixed-species meat and bone meal, high-bone meat and bone meal, poultry byproduct meal, and hog hair meal was 4, 53, 28, 8, 42, and 9%, respectively, relative to CuSO4. Feather meal did not provide any bioavailable Cu to chicks.

Animal Feed↗

Effect of microbial phytase and 1,25-dihydroxycholecalciferol on dietary copper utilization in chicks.

Bile Cu accumulation in Cu-depleted chicks fed Cu concentrations between .56 and 1.56 mg Cu/kg (0, .5, or 1 mg supplemental Cu/kg) was used to investigate the effect of microbial phytase at 600 U/kg and 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] at 10 micrograms/kg on Cu bioavailability from dehulled soybean meal (SBM) and cottonseed meal (CSM). The bioavailability of Cu (relative to CuSO4.5H2O, which was set at 100%) in SBM and CSM was 43 and 39%, respectively. Phytase addition (600 U/kg diet) decreased Cu bioavailability in SBM to 21%, but did not affect that in CSM (34%). Copper bioavailability in SBM was not affected by addition of 1,25-(OH)2D3 (10 micrograms/kg diet), but that in CSM was nearly doubled by 1,25-(OH)2D3 supplementation.

6-Phytase↗

Effect of high copper dosing on hemicellulose digestibility in cecectomized cockerels.

A precision-fed cockerel digestibility assay using ground corn cobs was conducted to test a theory that birds fed pharmacological doses of Cu (250 mg Cu/kg diet) may exhibit a higher hemicellulose digestibility due to increased release of lysosomal enzymes in the bile. Finely ground corn cobs were crop intubated into adult cockerels that had been pretested on diets containing either 0 or 250 mg Cu/kg (from CUSO4.5H2O). Copper-loaded cockerels showed higher (P < .05) true dry matter digestibility, hemicellulose digestibility, and TMEn than the control cockerels. True dry matter digestibility of corn cobs was 11.1% in Cu-loaded cockerels, which was nearly double that observed (6.2%) in control cockerels. Hemicellulose digestibility also increased from 22.1% in control cockerels to 36.6% in Cu-loaded cockerels. Copper-loaded cockerels obtained some TMEn (117.7 kcal/kg) from corn cobs, whereas the control cockerels obtained no TMEn from the corn cob intubation. The preliminary results presented herein demonstrate that pharmacological doses of dietary Cu may improve hemicellulose digestibility, which may in part explain the growth-promoting effect of Cu.

Animal Nutritional Physiological Phenomena↗

Iron requirement of chicks fed a semipurified diet based on casein and soy protein concentrate.

An Fe depletion and repletion study was conducted to determine the Fe requirement of chicks fed a casein-dextrose diet containing soy protein concentrate. Weight gain, hematocrit, hemoglobin, and serum total Fe showed marked increases when graded levels (0, 5, 10, 20, 30, 40, and 50 mg/kg) of Fe from analytical grade FeSO4.7H2O were added to an Fe-deficient basal diet containing 46.5 mg Fe/kg. Subjecting the hemoglobin data to broken-line analysis indicated that the Fe requirement was 38.5 mg/kg of supplemental Fe (i.e., total dietary Fe of 85 mg/kg). Heart hypertrophy was observed in Fe-deficient chicks, but Fe supplementation (more than 20 mg/kg) alleviated the problem.

Animals↗

[A morphological study of the human ventricular fold: age-related changes and sex differences].

A morphological study of the human ventricular fold was conducted with special reference to age-related changes and sex differences. The laryngeal specimens examined were obtained from 54 autopsy cases consisting of 27 males and 27 females ranging in age from 20 to 79 years. Each specimen was frontal-sectioned between the anterior and posterior ends of the ventricular fold to yield 8 equal portions. The surface of the entire ventricular fold was reconstructed based on examination of all of the sections, and extent of squamous metaplasia was 3-dimensionally evaluated and expressed in the form of a histological map. In the cases in which smoking history was ascertained, extent of squamous metaplasia was evaluated by the same method. In all of the cases the distribution of the different types of tissues such as glandular, adipose and connective, was examined in the midportion of the specimen (section No. 5). The following conclusions were drawn as a result. 1. The development of squamous metaplasia reached a peak in the middle-age group, particularly in males. The 3-dimensional extension of metaplasia was classified into 4 patterns, however, there were no age-specific differences in pattern, and the posterior-dominant-type and widespread-type were the most common in all age groups. The extension of metaplasia varied with smoking history, suggesting that smoking promotes the extension of squamous metaplasia. 2. Glandular tissue decreased with age, more markedly in females. The distribution of the glandular tissue was classified into 4 patterns. Atrophy of glandular tissue with age occurred in the central area of the ventricular fold, extending to the marginal portion. 3. Collagen fibers decreased slightly with age. Elastic fibers appeared frequently in the lateral portion near the laryngeal ventricle in the aged group.

Adult↗

[Simultaneous operation for annulo-aortic ectasia, mitral regurgitation, and tricuspid regurgitation in a patient with Marfan syndrome--report of a case].

A 57-year-old man with manifestations of Marfan syndrome was referred for detail examination of cardiac murmur to our hospital. Cardioangiography showed moderate aortic valve regurgitation (2/4), and severe mitral valve regurgitation (3/4), in addition to aneurysmal dilatation of the aortic root. Moderate tricuspid valve regurgitation (2/4) was also detected by Doppler echocardiography. Aortic root replacement with the Cabrol technique, mitral valve replacement with a St. Jude Medical valve, and repair of the tricuspid valve with the bicuspidalization technique were simultaneously performed in this patient. His postoperative recovery was uneventful. In this study, we discuss about the indications of simultaneous aortic root replacement and mitral valve replacement in a patient with Marfan syndrome.

Aorta↗

[Reconstructive surgery for acquired mitral regurgitation].

Between December, 1967, and July, 1994, 96 patients underwent repair of the mitral valve for acquired mitral valve regurgitation. According to Carpentier's classification, mitral valve pathology resulting in valve regurgitation was classified into three types; 4 patients assigned to type I, 63 type II, and 29 type III. The operative mortality rate was 1.0%. Follow-up data were available in 95 patients from 0.5 year to 25.3 years (mean average 8.8 years). The late mortality rate were not different between patients with valve pathology of type I, II and those with valve pathology of type III. Thromboembolism occurred on three patients for an embolic rate of 0.4% per patient-years. Twenty-eight patients required reoperation for residual MR and dehiscence of suture lines (type II; 10 cases, reoperation-free rate at 20 years, 83.2%) or recurrent MR due to progression of valve deformity (type III, 18 cases, reoperation-free rate at 20 years, 14.8%). These results demonstrate that patients with type I and II valve are good candidates for MVP, and that high incidence of reoperation for recurrent MR may limit the application of MVP to selected patients with type III valve.

Adolescent↗

Aortic regurgitation due to non-traumatic rupture of the aortic valve commissures: report of two cases.

Two cases of severe aortic regurgitation due to non-traumatic rupture of the aortic valve commissures are reported. The cause of rupture was hypertension in one patient, but it could not be identified in the other, where microscopic examinations of the aortic wall and the aortic cusps showed no particular pathologic changes. M-mode echocardiography revealed enlargement of the left ventricle, diastolic flutter of the anterior mitral leaflet and diastolic separation of the closure line of the aortic cusps in both patients. Two-dimensional echocardiography showed a downward displacement of the prolapsing motion of the aortic valve cusp during diastole toward the left ventricular outflow tract in one patient, and eccentricity of the coaptation point of the aortic valve without thickening of the cusps in the other. In addition to clinical features of progressive heart failure and characteristic cardiac murmur, echocardiographic studies provided correct diagnosis of aortic valve prolapse resulting from rupture of the aortic valve commissures. Both patients underwent aortic valve replacement successfully.

Aortic Valve↗

Long-term results after conservative aortic valve repair for aortic regurgitation with ventricular septal defect.

Aortic valve repair was performed in 61 patients having aortic regurgitation (AR) associated with ventricular septal defect (VSD). Preoperative regurgitation was classified according to the Sellers' classification and grade I was in 3 patients, grade II in 19, grade III in 34, and grade IV in 5 patients. Forty-six patients underwent only plication of aortic valve, and in 15 patients the commissuroplasty was added to reinforce the free edge of the cusp. Furthermore, aortoplasty (aortic annuloplasty) was performed in 11. Actuarial survival rate and freedom from reoperation rate were 91.6% and 87.2%, respectively at 10 years after the initial repair. The rate of freedom from deterioration for 22 patients showing grade I or II of AR before the initial operation was 86.4% at 1 year, 76.7% at 5 and 10 years, while the rate for 36 patients with grade III or more severe AR was 91.7% at 1 year, 77.4% at 5 years and 63.9% at 10 years. The rate at 10 years after operation between the two groups was different significantly (p < 0.05). Twenty among 22 patients having grade I or II of AR before operation were in NYHA class I, while 23 of 30 survivors with grade III or IV of AR were in class I, 6 in class II, and 1 in class III. Eight patients received reoperation and four of them underwent repeated conservative aortic valve repair, and one received aortic valve replacement at reoperation. Five of 7 survivors with reoperation improved in NYHA class I and 2 in class II. These results suggested that careful follow-up was required especially for the first 10 years after the initial operation in patients showing preoperative severe AR and receiving aortic repair.

Adolescent↗

Tricuspid valve replacement with the St. Jude Medical valve.

A study was conducted on 20 patients who underwent tricuspid valve replacement (TVR) with the St. Jude Medical (SJM) valve. Isolated TVR was performed on 9 patients, and additional mitral, or mitral and aortic valve replacements were performed on 11 patients. Four patients (20%) died in the early postoperative period, but there were no deaths related to the SJM valve in the tricuspid position. The mean follow-up period of the 16 survivors was 74.4 months, and there have been no deaths during the follow-up period. The postoperative actuarial survival rate was 80%, 10 years after surgery. Three patients, representing 0.25%/patient-months, developed valve thrombosis, the valve thrombosis-free rate being 72.8%, 10 years after surgery, while entrapment of a leaflet by endothelial pannus was found in one patient, representing 0.08%/patient-months. Thus, the incidence of all prosthetic valve-related complications was 0.34%/patient-months, and the postoperative complication-free rate was 65.3%, 10 years after surgery. The medium-term follow-up study of TVR with the SJM valve revealed no prosthetic valve-related deaths and a relatively low incidence of prosthetic valve-related complications. However, as with other mechanical valves, valve thrombosis was a major risk posed by the SJM valve in the tricuspid position.

Actuarial Analysis↗

Methicillin-resistant Staphylococcus aureus endocarditis following patch closure of a ventricular septal defect: report of a case.

We report herein the case of a 5-month-old infant who, after developing methicillin-resistant Staphylococcus aureus (MRSA) endocarditis following patch closure of a ventricular septal defect (VSD), was successfully treated by replacement of the Dacron patch with an autogenous pericardial patch. Initially, a large perimembranous VSD was repaired with a Dacron patch and after an uneventful recovery of 1 week, he began to spike intermittent fevers from 38 degrees C to 39 degrees C. Two blood cultures grew MRSA and a two-dimensional echocardiogram performed 16 days after surgery showed an irregular mass attached to the right ventricular aspect of the Dacron patch. At reoperation, a large vegetation attached to the Dacron patch was confirmed, but there was no patch dehiscence. Following removal of the patch, the VSD was repaired with an autogenous pericardial patch, soon after which the fever rapidly subsided. Imipenem, 125 mg every 6 h, and fosfomycin, 300 mg every 6 h, were administered for a total of 24 days after reoperation. The child remains well 12 months after his second operation.

Endocarditis, Bacterial↗

Limited effectiveness of FK506 administration for ongoing rejection in heterotopic rat heart transplantation.

A comparison was made of the histological findings for myocardial tissue of heterotopic transplanted rat hearts administered with FK506. ACI rats were used as donors and Lewis rats as recipients. FK506 was used for 6 days except for group I (control group). Group II received 0.32 mg/kg/day of FK506 from the day of operation while group III was given the same dosage from the 4th day after transplantation. Group IV was given 1.28 mg/kg/day of the agent from the day of grafting and group V received the same dose from the 4th postoperative day. The graft survival time was longer for all groups given FK506, but was significantly longer only for groups administered with FK506 from the day of operation. Histological studies performed 10 and 20 days after transplantation showed that a moderate rejection was seen in about half of the grafts receiving FK506 from the 4th day after grafting. An ultrastructural study of these cases showed that infiltrating large lymphocytes still remained in the interstitial tissues and that the cytoplasmic organelles of the myocytes had been focally destroyed. These results suggest that, although FK506 suppressed any further rejection, the effect might be limited and the myocardial changes of the cardiac graft might persist even after administration for ongoing rejection.

Animals↗

Nonsurgical correction for thrombosis of a St. Jude Medical tricuspid prosthesis: report of a case.

A 43-year-old woman with rheumatic heart disease underwent replacement of the aortic, mitral, and tricuspid valves using three SJM prostheses. Despite adequate warfarin therapy, routine cineradiography performed on the 40th postoperative day showed one of the leaflets of the tricuspid prosthesis to be "stuck" in the semiclosing position. A thrombosis of the tricuspid prosthesis was successfully treated with a urokinase infusion and mechanical thrombolysis using a pacemaker, following which normal valve function was restored.

Adult↗

Aortic root replacement with a composite graft: results of 69 operations in 66 patients.

Between December 1973 and December 1992, 66 patients underwent aortic root replacement at our hospital. The mean age of the patients was 42.5 years (range, 20 to 71 years); 44 patients were male and 22 were female. Of the 66 patients, 34 (51.5%) had clinical stigmata of Marfan's syndrome. The aortic pathology requiring aortic root replacement was annuloaortic ectasia in 59 patients, aortic dissection in 5, and progressive dilatation of the ascending aorta after aortic valve replacement in 2. Twelve of the 59 patients with annuloaortic ectasia also had aortic dissection. The operative techniques used were the Bentall technique in 36 operations, the Cabrol technique in 21, the aortic button technique in 3, and other miscellaneous techniques in 9. The hospital mortality rate for the primary operation was 10.6% (7 patients), and the late mortality rate was 20.3% (12 patients). Four of the late deaths were related to the graft valve prosthesis, and 6 were related to the progression of aneurysmal diseases on the remaining aorta. The survival rate was 71.0% at 10 years. Pseudoaneurysm at the suture lines was detected in 7 patients, 6 of whom had been treated with the Bentall technique, and 5 patients also had Marfan's syndrome. No patients having aortic root replacement with the Cabrol technique have required reoperation for pseudoaneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗