Search PubMed⌕ Search

Biomedical subjects

S Aoyagi

Publications and source records attributed to S Aoyagi.

At least 199 records · Page 11Linked to original sources
PubMed1994

Surgical treatment for acute aortic dissection and coexistent degenerative aortic aneurysm. Report of three cases.

Acute aortic dissection occurring in an aorta previously afflicted with degenerative, atherosclerotic is unusual. We report three cases with acute aortic dissection (DeBakey type III-b) occurring in an aorta which had a preexistent degenerative aortic aneurysm. Two of the three patients had acute aortic dissection originating from the distal end of the degenerative aneurysm, and the remaining one had the acute aortic dissection and degenerative aneurysm at different segments of the aorta. Since the risk of rupture is likely to be much higher in the patients with coexistence of acute aortic dissection and degenerative aortic aneurysm, compared with patients with DeBakey type III acute aortic dissection alone, we believe that a prompt and aggressive surgical approach is essential to prevent rupture, and that digital subtraction angiography (DSA) is more helpful in making a correct diagnosis and in helping to decide surgical procedures and supportive methods than other noninvasive diagnostic procedures.

Acute Disease↗
PubMed1994

False aneurysm of the ascending aorta with fistula to the right atrium. Noninvasive diagnosis by computed tomographic scan and two-dimensional echocardiography with successful repair.

A 57-year-old Japanese man presented with symptoms of congestive heart failure 9 years after aortic valve replacement. On auscultation, a continuous murmur was heard at the left lower sternal border. Chest radiograph showed moderate cardiomegaly and a widened upper mediastinum. Computed tomographic scans showed a dilated ascending aorta, in which there was no intimal flap, and also showed a large mass which compressed the right atrium. Two-dimensional Doppler echocardiography revealed abnormal continuous blood flow directed from the dilated ascending aorta to the right atrium and no periprosthetic leak. At operation, a false aneurysm of the ascending aorta which originated from the aortotomy suture line and a fistula from the aorta to the right atrium were confirmed. The fistula was closed with pledgeted sutures, and the ascending aorta was replaced with a collagen-coated double woven velour dacron graft. The patient recovered uneventfully. Computed tomographic scan and two-dimensional echocardiography are complementary techniques for reliable non-invasive assessment of the complexity of an aortic aneurysm.

Aneurysm, False↗
PubMed1994

Surgical treatment of aneurysms of the aortic arch using a simplified selective cerebral perfusion technique.

Between April 1989 and October 1993, 35 patients underwent aortic arch reconstruction for aneurysms using cardiopulmonary bypass (CPB) with selective cerebral perfusion (SCP). Of the 35 patients, the initial 19 (Group P) consecutively received simplified SCP (partial brachiocephalic perfusion; PBP), and the next 16 (Group S) were consecutively treated with standard SCP. For cerebral protection, blood was supplied to the right axillary artery in Group P, and to the right axillary and the left common carotid arteries in Group S. The aneurysms was aortic dissection in 24 patients, and was secondary to arteriosclerosis in the remaining 11. Partial replacement of the aortic arch together with the ascending aorta was the most commonly performed procedure in both groups. The cardiopulmonary bypass time and the cardiac arrest time were not significantly different between the two groups. The overall cerebral perfusion time was significantly longer in Group S (100 min) than in Group P (65 min); however, when 2 patients with an accidental prolongation of the cerebral perfusion time in Group S were excluded, there was no significant difference in the cerebral perfusion time between the two groups. Early death occurred in 3 patients (15.8%) in Group P, and 2 patients (12.5%) in Group S, however, there were no deaths related to the selective cerebral perfusion technique, and there were no late deaths in either group. Cerebral complications were seen in 1 patient in each group (6.3% vs. 6.7%, not significant). These results suggest that the simplified SCP (PBP) under hypothermic CPB provides as satisfactory cerebral protection as standard SCP, so long as the patency of the circle of Willis is confirmed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Copper-amino acid complexes are partially protected against inhibitory effects of L-cysteine and L-ascorbic acid on copper absorption in chicks.

Chick experiments were conducted to investigate whether two new Cu-amino acid complexes, Cu-methionine (Cu-Met) and Cu-lysine (Cu-Lys), would differ from a standard Cu source (analytical-grade CuSO4) in their reaction to the inhibitory dietary effects of physiologic doses of L-cysteine (4000 mg/kg diet) or L-ascorbate (1000 mg/kg diet) on Cu absorption. Whether absorbed actively (as evaluated by a bile Cu assay at low Cu doses) or passively (as evaluated by a liver Cu assay at high Cu doses), cysteine inhibited Cu absorption more than did ascorbate. In addition, the inhibitory effects of cysteine and ascorbate were not additive, but they enhanced the inhibitory effect of Zn when evaluated at low Cu doses. Ascorbate inhibited Cu utilization from CuSO4 to 58.0% of the unsupplemented reference group at low Cu doses, which was greater (P < 0.05) than the inhibitory effect of ascorbate of Cu-Lys (78.7%) or Cu-Met (89.1%). Cysteine inhibited Cu utilization from CuSO4, Cu-Lys and Cu-Met at low Cu dose levels to 49.1, 44.1 and 50.2%, respectively, of unsupplemented reference groups of each source. These values were not different from each other. On the other hand, cysteine inhibited Cu utilization from CuSO4 to 8.5% of the unsupplemented reference group at high Cu doses, which was greater (P < 0.05) than the inhibitory effect on Cu-Lys (29.5%) or Cu-Met (39.9%). Ascorbate reduced Cu utilization from CuSO4, Cu-Lys and Cu-Met at high Cu doses to 72.8, 63.7 and 68.3%, respectively, of unsupplemented control groups of each source.

Animals↗
PubMed1994

Dietary L-homoarginine has no lysine bioactivity in chicks.

A chick growth assay was conducted to investigate the effect of dietary L-homoarginine supplementation on performance of chicks fed a Lys-deficient corn-feather meal diet. Weight gain, feed intake, and feed efficiency increased linearly (P < .01) as Lys was added at .1 and .2% from feed-grade L-Lys.HCl. Adding homoarginine at .2% resulted in less (P < .05) weight gain and feed intake than observed in chicks fed the unsupplemented basal diet. These data suggest that dietary homoarginine had no Lys bioactivity, but may also have antagonized Lys utilization from the basal diet.

Animals↗
PubMed1994

Limiting order of amino acids in corn and soybean meal for growth of the chick.

Several experiments were conducted with crossbred chicks during the period 8 to 22 d posthatching to establish the limiting order of amino acids (AA) in corn and dehulled soybean meal (SBM) and in a corn-SBM mixture. Cecectomized adult cockerels were used to determine true AA digestibilities in both corn and SBM, and AA fortification levels were based upon bringing digestible AA levels to their ideal levels (expressed as a percentage of CP). Ideal ratios (percentage of lysine) used were Lys, 100; sulfur AA (SAA), 72; Arg, 105; Val, 77; Thr, 67; Trp, 16; Ile, 67; His, 37; Phe+Tyr, 105; and Leu, 111. Diets were fed at 10% CP, but they contained corn or SBM in amounts that would just meet the ideal concentration of the AA in greatest excess (Leu for corn; Phe for SBM). Thus, the corn diets contained only 5.6% CP from corn whereas the SBM diets contained only 8.0% CP from SBM. Diets were adjusted to 10% CP from AA additions, with glutamate varying as necessary. The limiting order of AA in corn was 1) Lys, 2) Thr, 3) Trp, 4) Arg, Ile, and Val, 5) Met+cystine, 6) Phe+Tyr, and 7) His. In SBM, the limiting order was 1)Met+cystine, 2) Thr, 3) Lys and Val, 4) nonspecific amino nitrogen, and 5) His. The order of limiting AA in the corn-SBM mixture was 1) Met, 2) Thr, 3) Lys, 4) Val, 5) Arg, and 6) Trp.

Amino Acids↗
PubMed1994

Long-term results of valve replacement with the St. Jude Medical valve.

Between 1980 and 1992, 908 patients underwent single aortic (n = 178), single mitral (n = 577), or double aortic and mitral (n = 153) valve replacement with the St. Jude Medical valve at our hospital. There were 392 male patients and 516 female patients whose ages ranged from 1.2 to 74 years (mean, 52 years). The early mortality rate was 5.0% (45 patients). A 94% complete follow-up was accomplished for 863 patients who were discharged from the hospital (4682.3 patient-years). Sixty-nine of these patients died, for a late mortality rate of 8.0%. Fifty-two patients, including four patients (0.3%/100 patient-years) had anticoagulant-related hemorrhage, 4(0.1%/100 patient-years) had prosthetic valve endocarditis, 11 (0.2%/100 patient-years) had nonstructural valve dysfunction, and 16 (0.3%/100 patient-years) underwent reoperation. There were no structural valve failures in this series. The total number of valve-related deaths was 22. Of those patients who survived, 98% were in New York Heart Association functional class I or II at the date of the last follow-up. The probabilities of freedom from thromboembolism and anticoagulant-related hemorrhage at 10 years were 94% +/- 2% and 97% +/- 2% in aortic valve replacement, 89% +/- 2% and 98% +/- 4% in mitral valve replacement, and 89% +/- 6% and 92% +/- 6% in double valve replacement, respectively. Significant hemolysis related to the St. Jude Medical valve occurred in 8 of the 577 patients who received mitral valve replacement in our early experience, and modifying the valve orientation appeared to play an important role in reducing hemolysis. The event-free rate, including all complications and late deaths, at 10 years was 75% +/- 7%, 74% +/- 3%, and 81% +/- 6% in aortic valve replacement, mitral valve replacement, and double valve replacement, respectively. On the basis of these results, the St. Jude Medical valve seems to be an excellent mechanical valve in terms of durability and low thrombogenicity and remains our prosthetic valve of choice when valve replacement with a mechanical valve is indicated.

Adolescent↗
PubMed1994

[Reoperations for prosthetic heart valves: operation techniques and determinant factors of operative mortality].

Between 1982 and 1993, 93 patients underwent reoperation for prosthetic heart valves at our hospital. There were 41 male and 52 female patients who ranged in age 2 to 70 years with a mean age of 47 years. Twenty-four patients were in New York Heart Association (NYHA) functional class II, 52 in class III, and 17 in class IV, preoperatively. The indications of reoperative valve surgery were primary tissue failure of a bioprosthesis in 57 patients, valve thrombosis in 10, nonstructural valve dysfunction in 12, cloth wear of a ball valve in 5, endocarditis in 5, and others in 4. In reoperation, the heart was not mobilized from the pericardium to prevent tearing the heart and great vessels. All operative procedures were performed through the pericardium which adhered tightly to the heart. Adequate myocardial protection was obtained without total dissection of the heart with cold crystalloid cardioplegic solution and topical cooling which was accomplished by filling the left pleural space with cold saline. The operative mortality was 7 of the 93 patients (7.5%), falling from 4/36 (11.1%) in 1982 through 1987 to 3/57 (5.3%) in 1988 through 1993. Advanced New York Heart Association functional class, prolonged cardiopulmonary bypass and aortic cross clamping times were the determinant factors of operative mortality. These results suggest that reoperation for dysfunctioning prosthetic heart valves should be performed before deterioration of the hemodynamic condition of the patient.

Adolescent↗
PubMed1993

Partial brachiocephalic perfusion in aortic arch replacement.

Eleven patients who underwent replacement of the aortic arch or adjacent areas for aneurysmal disease between 1989 and 1991, using hypothermic cardiopulmonary bypass at 20 degrees to 23 degrees C with partial brachiocephalic perfusion, were studied. Selective perfusion of the innominate artery was performed in all 11 patients through the right axillary artery, while partial brachiocephalic perfusion was carried out using a separate arterial roller pump with a perfusion flow rate of 10 ml/kg per min. Direct cannulation to the left common carotid and left subclavian artery was not performed in this method. There were 4 men and 7 women who ranged in age from 26 to 78 years, with a mean age of 56 years. The etiology of aneurysmal disease was aortic dissection in 10 patients, and aortitis syndrome in 1. The cardiopulmonary bypass time was 214.3 +/- 39.3 min, aortic cross-clamp time 131.5 +/- 33.4 min, and partial brachiocephalic perfusion time 57.6 +/- 15.1 min. There were three operative deaths (27.3%), the causes being multiple organ failure, acute peritonitis, and infection of the composite graft in the ascending aorta, in one patient each, respectively. However, there were no deaths related to the technique of partial brachiocephalic perfusion and no neurological complications were seen in this series. Thus, we believe that partial brachiocephalic perfusion under hypothermic cardiopulmonary bypass is safe and effective in surgery for aortic aneurysms involving the aortic arch.

Adult↗
PubMed1993

Obstruction of the St. Jude Medical valve--diagnostic and therapeutic values of cineradiography.

Between 1984, and 1992, we observed 8 patients with an obstructed St. Jude Medical (SJM) valve. Of these, 1 had an obstructed SJM valve in the aortic position, 3 in the mitral position, and 4 in the tricuspid position. Diagnosis of obstruction of the SJM valve was made by cineradiography combined with echocardiography in all 8 patients. Restriction or absence of movement of the leaflet of the SJM valve was observed by cineradiography in all of the 8 patients. Normal range of leaflet mobility of the SJM valve was measured by conventional cineradiography in 70 patients with a normal SJM valve, and the results were compared with the leaflet mobility obtained from the 8 patients with an obstructed SJM valve. In this study, leaflet function in the obstructed SJM valve was strikingly abnormal, with both opening and closing angles, and leaflet motion clearly outside the normal range. Of the 8 patients, 4 underwent urgent prosthetic valve replacements after cineradiography and echocardiography were carried out. Thrombolysis using urokinase was performed in 4 patients, and this treatment was successful in 1 patient. Efficacy of thrombolytic therapy was evaluated by repeat cineradiography. Three of the 4 patients who received thrombolysis showed no significant improvement of leaflet mobility after at least 72 hours of thrombolytic therapy, and finally required surgical correction for the obstructed SJM valve. We believe that cineradiography combined with echocardiography is the optimal method for the diagnosis of obstruction of the SJM valve, and to follow the effect of thrombolytic therapy on prosthetic valve function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Biological efficacy of copper in chicken bile.

Newly hatched chicks were fed a Cu-deficient casein-soybean concentrate diet (0.56 mg Cu/kg) during an 8-d pretest period, after which they were fed experimental diets containing graded levels of added Cu from CuSO4.5H2O during a 15-d assay period. Following the Cu-depletion period, gall bladder Cu concentration decreased from 645 nmol/g dry matter at hatching to 60 nmol/g dry matter at d 8 posthatching; liver Cu concentration decreased during the same period from 255 to 225 nmol/g dry matter. During the subsequent 15-d repletion period, a sevenfold linear increase in gall bladder Cu occurred as Cu was supplemented up to 2 mg Cu/kg, after which it declined gradually in birds fed graded doses between 2 and 16 mg Cu/kg. Liver Cu also increased linearly as Cu was supplemented up to 2 mg/kg; when chicks were fed between 2 and 16 mg/kg of supplemental Cu, liver Cu concentration remained constant. Bile obtained from chicks fed 800 mg Cu/kg diet for 22 d was freeze-dried, analyzed and found to contain 3.05 mumol Cu/g dry matter. When 8-d-old Cu-depleted chicks were fed graded levels of supplemental Cu (0, 0.5 and 1.0 mg Cu/kg) from CuSO4.5H2O, bile Cu concentration increased linearly from 10.5 to 102.7 mumol/L. Bile Cu did not increase when freeze-dried bile (1.0 mg Cu/kg diet) was supplemented. When 0.5 mg Cu/kg from CuSO4.5H2O was supplemented in combination with 0.5 mg Cu/kg from freeze-dried bile, bile Cu concentration was less than one-half the level present in chicks fed 0.5 mg Cu/kg from CuSO4.5H2O alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Beneficial effect of the addition of nitroglycerin to the cardioplegic solution on the cold-stored reperfused isolated rat heart.

We discuss here the effect of the addition of trinitroglycerin to the cardioplegic solution on the isolated rat heart after eight hours of storage. This effect was evaluated by measuring cardiac function as well as myocardial calcium and enzymes. Male Wistar rats were divided into three groups based on the concentration of trinitroglycerine in the cardioplegic solution. In the control group, the fluid used was a crystalloid cardioplegic solution (K+ 25 mEq/L) without trinitroglycerin and for groups I and II, trinitroglycerin was added at concentrations of 2 micrograms/ml and 5 micrograms/ml, respectively. All hearts were arrested with the cardioplegic solution at 4 degrees C and then immersed for eight hours in Euro-Collins' solution at 4 degrees C. The postperfusion coronary flow showed higher rates for groups I and II than for the control group (p < 0.05), while the difference between groups I and II was not significant. In group I, the total concentrations of creatine kinase-MB, lactate and malondialdehyde after reperfusion showed the lowest levels; this group also had the lowest content of myocardial calcium. These results indicate that the addition of nitroglycerin, especially at a concentration of 2 micrograms/ml, to the cardioplegic solution elicits better cardiac function for immersed rat heart.

Animals↗
PubMed1993

Nutritional evaluation of copper-lysine and zinc-lysine complexes for chicks.

Three chick experiments were conducted to evaluate two mineral-Lys complexed products, Cu-Lys and Zn-Lys. Relative bioavailability of Lys, Cu, and Zn were assessed separately using diets specifically deficient in each of these nutrients and by employing criteria that respond in a straight-line fashion to supplementation with the nutrient in question. Common-intercept multiple linear regression (slope-ratio) of weight gain, bile Cu concentration, and total tibia Zn regressed on supplemental intake of Lys, Cu, and Zn, respectively, were used to assess bioavailability values relative to the standards (i.e., L-Lys.HCl, CuSO4.5H2O, and ZnSO4.H2O). Lysine bioavailability of Cu-Lys and Zn-Lys were estimated as 89 and 109%, respectively, which were not different (P > .05) from 100%. Relative bioavailability of Cu in Cu-Lys and Zn in Zn-Lys were estimated as 120 and 106%, respectively. These values were not different (P > .05) from the standards, i.e., CuSO4.5H2O for Cu and ZnSO4.H2O for Zn.

Animals↗
PubMed1993

Bioavailability of copper in analytical-grade and feed-grade inorganic copper sources when fed to provide copper at levels below the chick's requirement.

Young chicks were fed a casein-soy protein concentrate basal diet (.56 mg Cu/kg) containing graded levels of added Cu (0, .5, 1.0 mg/kg) from analytical-grade (AG) CuSO4.5H2O, Cu2O, CuO, CuCO3.Cu(OH)2, CuCl, and also from feed-grade (FG) CuSO4.5H2O and FG-CuO. Weight gain, hematocrit, hemoglobin, plasma Cu, liver Cu, gall bladder (bile) Cu, and tendon lysine were assessed to determine whether dose-dependent Cu responses would occur. Gall bladder Cu concentration as well as total Cu content of the gall bladder were found to be linear functions of supplemental Cu intake. Common-intercept multiple linear regression (slope-ratio) of bile Cu concentration regressed on supplemental Cu intake indicated Cu bioavailability values (relative to the standard, AG-CuSO4.5H2O, set at 100%) of 97.9% for AG-Cu2O, 93.5% for FG-CuSO4.5H2O, and 112.9% for AG-CuCO3.Cu(OH)2. These values were not different (P > .05) from 100%. Relative bioavailability of Cu in AG-CuCl was 142.5%, which was different (P < .05) from the standard. Both AG-CuO and FG-CuO gave Cu bioavailability estimates not different (P > .05) from zero. The results indicate that when Cu levels are fed below the chick's requirement, bile Cu concentration is a sensitive indicator of net gut absorption of Cu.

Animal Feed↗
PubMed1993

Estimates of copper bioavailability from liver of different animal species and from feed ingredients derived from plants and animals.

Bile Cu accumulation in Cu-depleted chicks fed Cu concentrations between .56 and 1.56 mg/kg was used to estimate Cu bioavailability in several feed ingredients from both plant and animal sources, including liver from different species. Liver from slaughtered animals is rich in minerals and vitamins and is a significant source of Cu in canned pet foods. Liver from different species, however, was found to vary widely in Cu bioavailability (relative to CuSO4.5H2O, which was set at 100%). The bioavailability of Cu in freeze-dried (FD) chicken liver and poultry by-product meal was 116 and 97%, respectively, but that in FD pork liver was not different from zero. Relative bioavailability of Cu in FD beef, sheep, and turkey liver was 82, 113, and 83%, respectively. Copper in FD liver from the rat, a species that does not possess a gall bladder, was 21% bioavailable. Copper in the feed ingredients from plants: corn gluten meal, dehulled soybean meal, cottonseed meal, peanut hulls, and soy mill run was 48, 38, 41, 44, and 47% bioavailable, respectively. In addition, when the fibrous ingredients peanut hulls or soy mill run were added to the basal diet containing .5 mg Cu/kg from CuSO4.5H2O, Cu bioavailability in CuSO4.5H2O was reduced. The results of this study demonstrate a wide variation in Cu bioavailability among feed ingredients originating from plants and animals.

Analysis of Variance↗
PubMed1993

Nutritional evaluation of a copper-methionine complex for chicks.

Three chick experiments were conducted to evaluate a new Cu complex product, Cu-Met. Relative bioavailability of Cu was assessed with two bioassay systems, one employing bile Cu concentration as the criterion at Cu-deficient levels and another employing liver Cu concentration at Cu-excess levels. Relative bioavailability of Met was assessed separately. Common-intercept multiple linear regression (slope-ratio) of bile Cu concentration or liver Cu concentration regressed on supplemental Cu intake was used to assess Cu bioavailability relative to the standard, analytical-grade CuSO4.5H2O, which was set at 100%. In addition, Cu-Lys and CuCl (compounds previously evaluated by bile Cu concentration) were evaluated by the liver Cu accumulation method. Relative bioavailability of Cu in Cu-Met was estimated as 96% by the bile Cu assay and 88% by the liver Cu assay, which were not different (P > .05) from 100%. The liver Cu assay estimated that relative Cu bioavailabilities in Cu-Lys and CuCl of 114 and 145% (P < .05), respectively. These values were very close to those previously estimated by the bile Cu assay. Relative Met bioavailability of Cu-Met was 100% of the standard, i.e., feed-grade DL-Met.

Animal Feed↗
PubMed1993

[The preventive effect of additional albumin in crystalloid cardioplegic solution on myocardial reperfusion injury].

The effect of additional albumin in crystalloid cardioplegic solution (CS) was investigated for infant with open heart surgery. Patients were divided into two groups; CS containing with or without 1% albumin. CS without albumin was administered for Group-I in 13 patients and CS with albumin for Group-II in 14 patients. The blood samples were collected from radial artery and coronary sinus at 5, 15 and 30 minutes after reperfusion and blood gas analysis, hemoglobin, lactate, creatine kinase-MB (CK-MB) and malondialdehyde (MDA) were measured. In percentage of CK-MB secretion, no significant differences were seen between two groups. However, in oxygen consumption, lactate and MDA secretion, significant differences between the groups were noted at five minutes after reperfusion. In conclusion, additional albumin in CS solution, especially in infant cases was effective for myocardial preservation immediately after reperfusion.

Albumins↗