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Biomedical subjects

S Miki

Publications and source records attributed to S Miki.

At least 127 records · Page 7Linked to original sources
PubMed1992

Acute pulmonary edema after Blalock-Taussig anastomosis.

Acute pulmonary edema developed in 2 patients after a Blalock-Taussig shunt procedure. Both patients had a univentricular heart complex with pulmonary stenosis. One patient underwent a modified Blalock-Taussig shunt using a polytetrafluoroethylene tube and the other underwent a classic Blalock-Taussig anastomosis. Acute pulmonary edema after the Blalock-Taussig shunt is rare, but once it has occurred, immediate treatment is obligatory.

Acute Disease↗
PubMed1992

Synthesis of sulfonate analogs of bile acids.

Sulfonate analogs of C23 and C24 bile acids were synthesized from norcholic, norchenodeoxycholic, norursodeoxycholic, nordeoxycholic, norhyodeoxycholic, cholic, deoxycholic, hyodeoxycholic, and lithocholic acids. The principal reactions used were (1) reduction of the bile acids with NaBH4 to the corresponding bile alcohols, (2) selective tosylation of the terminal hydroxyl group, (3) iodination of the tosyl esters with NaI, and (4) treatment of the iodides with Na2SO3 to form the sulfonate analogs of the bile acids. The sulfonate analogs showed polarity similar to that of taurine-conjugated bile acids on thin-layer chromatography. The carbon 13 nuclear magnetic resonance spectral data for the sulfonate analogs were tabulated.

Bile Acids and Salts↗
PubMed1992

Deep hypothermic systemic circulatory arrest and continuous retrograde cerebral perfusion for surgery of aortic arch aneurysm.

From 1987 to February 1991, we have repaired or replaced the aortic arch in ten patients using deep hypothermic systemic circulatory arrest with continuous retrograde cerebral perfusion (CRCP). CRCP can be implemented using the bypass connecting the arterial and venous lines of the extracorporeal circuit to reverse the flow into the superior vena cava cannula after induction of circulatory arrest. CRCP flow required to maintain an internal jugular vein pressure of 20 mmHg ranged from 100 to 500 ml/min. After completion of suturing of the aortic arch graft, air is evacuated retrogradely from the open arch vessels prior to reestablishing the usual arterial return. Two patients died, one from sepsis and the other from liver cirrhosis 1 month postoperatively. CRCP times ranged from 11 to 56 min, and minimal nasopharyngeal temperatures ranged from 16 degrees to 18 degrees C. The difference in oxygen content between the perfused blood and the blood draining from the arch vessels during CRCP most likely reflected the steady-state metabolism of the brain during the deep hypothermic state. This technique offers advantages including the need for dissecting and clamping the arch branches, providing sufficient metabolic support to the brain during deep hypothermia, and eliminating embolism of particulate debris from the aortic arch.

Adult↗
PubMed1992

Replacement of a thrombosed St. Jude Medical prosthesis in pulmonary position after repeated thrombolytic therapy.

A 49-year-old man who had undergone repair of tetralogy of Fallot underwent replacement of a thrombosed St. Jude Medical prosthesis in pulmonary position after intravenous thrombolytic therapy. Dysfunction of the prosthetic valve was detected clinically by change of heart sound and the appearance of a new diastolic murmur. Cinefluoroscopy confirmed fixation of both leaflets. Although thrombolytic therapy using urokinase was successful twice, the prosthesis was replaced with a Carpentier-Edwards bioprosthesis due to recurrent prosthetic dysfunction.

Adult↗
PubMed1992

Pharmacokinetics and efficacy of carvedilol in hypertensive patients with chronic renal failure and hemodialysis patients.

The efficacy, safety, and pharmacokinetics of carvedilol were investigated in an open trial performed on 13 hypertensive patients with chronic renal failure and six additional patients requiring hemodialysis. In hypertensive renal failure patients, treatment with carvedilol (5 mg/day) for 1 week produced a significant decrease in blood pressure (from 172/101 to 146/84 mm Hg) but did not change the heart rate. The pharmacokinetics of carvedilol did not change with repeated administration, and there was no accumulation of this drug. In hemodialysis patients with hypertension, the pharmacokinetics of carvedilol after a single dose of 10 mg did not vary between dialysis and nondialysis days, and blood pressure decreased significantly on both days. In addition, there was no accumulation of carvedilol during a 4-week trial of therapy, and blood pressure was decreased significantly from 170/93 to 145/83 mm Hg. There were no side effects and no abnormal laboratory findings noted during the trial. These results indicate that carvedilol is an effective and safe agent for hypertensive patients with chronic renal failure and for hemodialysis patients with hypertension and that dosage adjustments are probably not required in these clinical situations.

Adrenergic beta-Antagonists↗
PubMed1992

Comparison of lipids, apoproteins and associated enzyme activities between diabetic and nondiabetic end-stage renal disease.

Lipids, apoproteins and associated enzyme activities in type 2 diabetic end-stage renal disease (ESRD) were compared with that in nondiabetic ESRD and normal controls. Of the 40 uremic patients with non-insulin-dependent diabetes mellitus, 20 patients were receiving stable continuous hemodialysis treatment (CHT). Of the 39 patients with nondiabetic ESRD, 21 were undergoing CHT. Patients with nondiabetic ESRD exhibited elevated levels of serum triglyceride and a marked reduction in high-density-lipoprotein (HDL) cholesterol. Concentrations of serum apolipoprotein (Apo) C-3 were higher than in controls, whereas mean levels of serum Apo E were lower. The concentrations of serum Apo A-1 and Apo A-2 decreased with diminished lecithin: cholesterol acyltransferase activity. Lipoprotein lipase activity decreased in undialysed patients, and hepatic triglyceride lipase activity decreased significantly throughout the observation. Patients with diabetic ESRD exhibited elevated serum Apo B and normal serum Apo E levels, besides the lipid and Apo abnormalities observed in nondiabetic ESRD. Moreover, a prominent reduction in serum Apo A-1 was found in dialysed diabetic patients. The Apo B/Apo A-1 ratio was significantly higher in diabetic ESRD than in nondiabetic patients undergoing CHT. These results indicate that lipid abnormalities are accelerated in diabetic ESRD and may constitute a serious risk for the development of atherosclerosis.

Adult↗
PubMed1992

Segmental asynergy of the left ventricle in a case of tight aortic stenosis associated with mild ischemic heart disease.

Emergency aortic valve replacement with double aorto-coronary bypass surgery was performed to treat severe intractable congestive heart failure in an 82-year-old man. Mild circumflex and left anterior descending artery lesions were present and the pressure gradient across the aortic valve was 80 mmHg despite a low cardiac output. The preoperative anteroseptal akinesia seen by two-dimensional echocardiography was normalized after surgery. Thus, even in patients with segmental left ventricular dysfunction, tight aortic stenosis might be present when concomitant mild ischemic heart disease is present.

Aged↗
PubMed1992

[Increased granulocyte/macrophage colony stimulating factor production by mononuclear cells from patients with bronchial asthma].

The in vitro production of granulocyte/macrophage colony stimulating factor (GM-CSF) by mononuclear cells from the peripheral blood of patients with bronchial asthma (BA) was examined by enzyme-linked immunosorbent assay (ELISA). In 3 of 12 cases studied, mononuclear cells from BA patients produced GM-CSF without stimulation. And in 5 of 12 cases studied, mononuclear cells from BA patients produced GM-CSF in response to IL-2. Mononuclear cells from patients with other diseases (n = 13) and healthy volunteers (n = 6) did not release any detectable (> or = 7.5 pg/ml) GM-CSF. The culture media of mononuclear cells from BA patients showed activities for stimulating the proliferation and survival of eosinophils, and these activities were partially inhibited by anti-GM-CSF antibodies. GM-CSF production by mononuclear cells from BA patients treated with prednisolone was lower than that of mononuclear cells from untreated BA patients. And prednisolone showed a reduction in the GM-CSF production from mononuclear cells in response to IL-2. These results suggest that GM-CSF production by mononuclear cells may play a role in the pathogenesis of BA.

Adult↗
PubMed1992

Dopaminergic modulation of the pressure-natriuresis response in rats.

OBJECTIVE: The present study was carried out to examine the involvement of dopamine in the pressure-natriuresis phenomenon which has been postulated as a major regulator of extracellular fluid volume and thereby arterial pressure. DESIGN: Dopaminergic modulation of the pressure-natriuresis response was studied in the innervated and denervated rat kidney, to allow a distinction between the effects of neural and extraneural dopamine. METHODS: The pressure-natriuresis response was studied in anesthetized Sprague-Dawley rats, in which neural and hormonal influences on the kidney were fixed by denervating the kidney and by intravenous infusion of aldosterone, hydrocortisone, vasopressin and norepinephrine. The innervation to the kidney remained intact in some experiments with the selective dopamine-1 antagonist SCH 23390. Urinary excretion of dopamine during the pressure-natriuresis response was also examined in the innervated and denervated rat kidney. RESULTS: Although infusion of dopamine at a dose of 2 micrograms/kg per min had no effect on the pressure-natriuresis response in rats in which neural and hormonal influences on the kidney were fixed, the slopes of the relations between urine flow, sodium excretion and mean arterial pressure in rats given 10 micrograms/kg per min dopamine were significantly greater than those found in the control rats. Renal plasma flow increased significantly in the dopamine-treated rats whilst glomerular filtration rate did not differ between the control and dopamine-treated rats. The dopamine-induced increase in the slope of pressure-natriuresis relationship and renal plasma flow were completely blocked by 0.5 micrograms/kg per min SCH 23390. However, infusion of SCH 23390 alone at 0.5 micrograms/kg per min did not significantly alter the pressure-natriuresis response in rats with either denervated or innervated kidney. In addition, urinary excretion of dopamine derived from neither neural nor extraneural origins was altered in parallel with variations in mean arterial pressure. CONCLUSION: These results suggest that exogenous administration of dopamine may affect the pressure-natriuresis response by altering the magnitude of arterial pressure-induced changes in tubular sodium reabsorption, via an action of dopamine-1 receptors. However, endogenous dopamine does not appear to be capable of modulating the pressure-natriuresis response.

Animals↗
PubMed1992

Sulfonate analogues of chenodeoxycholic acid: metabolism of sodium 3 alpha, 7 alpha-dihydroxy-25-homo-5 beta-cholane-25-sulfonate and sodium 3 alpha, 7 alpha-dihydroxy-24-nor-5 beta-cholane-23-sulfonate in the hamster.

This report describes the chemical synthesis of a new bile acid analogue, namely, sodium 3 alpha, 7 alpha-dihydroxy-25-homo-5 beta-cholane-25-sulfonate from homochenodeoxycholic acid. The structure of the new compound was assigned by proton magnetic resonance and infrared spectrometry. Its metabolism was studied in the hamster in comparison with sodium 3 alpha, 7 alpha-dihydroxy-24-nor-5 beta-cholane-23-sulfonate and sodium taurochenodeoxycholate. After intraduodenal administration of the 3H-labeled analogues into bile fistula hamsters, both sulfonates were absorbed from the intestine and nearly 80% of the radioactivity was secreted into bile within 8 h. Intra-ileal administration revealed that these compounds resembled taurochenodeoxycholate in that they were much more rapidly absorbed from the ileum than from the proximal small intestine: more than 85% of the radioactivity was recovered in bile within 1 h. After intravenous infusion the sulfonates were efficiently extracted by the liver at rates similar to that of sodium taurochenodeoxycholate. Chromatographic analysis of the bile showed that, regardless of the route of administration, most (> 95%) of the sulfonates were not biotransformed and they became major biliary bile acids. Sodium 3 alpha, 7 alpha-dihydroxy-25-homo-5 beta-cholane-25-sulfonate and, to a lesser extent, sodium 3 alpha, 7 alpha-dihydroxy-24-nor-5 beta-cholane-23-sulfonate induced cholestasis at infusion rates at which sodium taurochenodeoxycholate produced choleresis.

Animals↗
PubMed1992

[Study of recombinant human erythropoietin treatment on the anemia of predialysis patients].

We conducted a multiple-center joint study on the effects of recombinant human erythropoietin (rEPO) for predialysis patients. rEPO was intravenously administered to 42 predialysis patients (13 males and 29 females) with hematocrit (Ht) levels of less than 30%. The subjects were divided into group A (28 cases) in which rEPO was administered twice a week, and group B (14 cases) with rEPO administration once a week. The initial administration dosage was 6000IU/week. The Ht levels were 22.6 +/- 3.3% for group A and 23.2 +/- 2.7% for group B before the administration of rEPO, and increased to 31.0 +/- 4.0% and 27.7 +/- 3.7% respectively twelve weeks after initiating administration. The levels of effective improvement on anemia included 'markedly effective' in 17 cases (80.9%) and 'effective' in 2 cases (9.5%) in group A, and 'markedly effective' in 5 cases (41.7%) and 'effective' in 3 cases (25.0%) in group B. No significant change was seen in serum creatinine (Cr) levels during the study period. In the evaluation of renal function by reciprocal serum creatinine (1/Cr), a consistent tendency was not recognized; thus, suggesting that the rEPO administration had no effect on the renal function. No variation of blood pressure was seen. As far as side effects were concerned, headache and heavy headedness were recognized in four cases. There were, however, no cases in which the severity of the side effects dictated the discontinuation of the rEPO administration. In conclusion, rEPO was judged to be a safe and effective treatment for the anemia of predialysis patients.

Adult↗
PubMed1992

Analysis of left ventricular motion after mitral valve replacement with a technique of preservation of all chordae tendineae. Comparison with conventional mitral valve replacement or mitral valve repair.

The postoperative regional left ventricular motion of 22 patients with a diagnosis of mitral regurgitation, and who underwent mitral valve replacement with preservation of chordae tendineae, were retrospectively analyzed by cineangiography in the early postoperative period and by multiple-gated cardiac blood pool scintigraphy in the mid-to-late postoperative period. The operation consisted of the division of the anterior leaflet into anterior and posterior segments, the shifting and reattachment of the divided segments to the mitral ring of the respective commissural areas, and the use of a low-profile bileaflet prosthetic valve. Control groups consisted of 28 patients with mitral regurgitation who underwent mitral valve replacement with a conventional technique and 16 patients who underwent mitral valve repair. Compared with the conventional mitral valve replacement group, the radial shortening of the left ventricle of the chordae-preserved mitral valve replacement group was greater at the apical septal, inferoapical, anterobasal, and anterolateral portions, whereas the radial shortening of the repair group was greater than that of the chordae-preserved group only at the inferolateral portion. The ejection fraction of the whole left ventricle was statistically greater in the chordae-preserved group, and also regional ejection fraction of the chordae-preserved mitral valve replacement group was greater at the apical septal, inferoapical, inferolateral, anterobasal, and anterolateral portions than that of the conventional mitral valve replacement group at these portions. On the other hand, the postoperative regional and global motion was identical to that of the mitral valve repair group except at the inferolateral portion. The result of this study supports a concept that maintenance of continuity between the mitral anulus and the papillary muscle has a beneficial effect on postoperative left ventricular performance.

Adult↗
PubMed1992

[Delayed onset of heparin induced thrombocytopenia--a case report].

A 64-year-old man underwent CABG. 18000 unit of bovine lung heparin was used during operation for extracorporeal circulation and small amount of heparin was injected until the 5th postoperative day to keep intravenous line patent. His postoperative course was uneventful until the 10th postoperative day when marked ecchymosis developed on his eyelid. Laboratory data showed marked thrombocytopenia (1.3 x 10(4)/microliters) and disseminated intravascular coagulation. The diagnosis of heparin-induced thrombocytopenia (HIT) was confirmed by platelet aggregation test with heparin. Gabexate mesilate and platelet-concentrates were administered and platelet count returned to normal within a week. HIT usually occurs during administration of heparin. In this case, it occurred 5 days after we stopped heparin. Delayed onset of HIT might be related to delayed metabolism of heparin due to postoperative fluid shift.

Coronary Artery Bypass↗
PubMed1992

Characterization of T-cell subsets, soluble interleukin-2 receptors and interleukin-6 in Vogt-Koyanagi-Harada disease.

The lymphocyte subunits and subsets of 12 patients with Vogt-Koyanagi-Harada disease (VKH disease) were characterized using two-color flow cytometry techniques, both in cerebrospinal fluid (CSF) and in peripheral blood (PB). Soluble interleukin-2 receptor (sIL-2R) levels and interleukin-6 (IL-6) levels were also measured. The percentage of T cells was significantly higher in CSF than in PB (P less than 0.01), but the percentage of B cells was decreased in CSF (P less than 0.05). As for T-cell subsets, the percentage of helper T cells was especially high in CSF (P less than 0.01). Also, the ratio of helper T cells/suppressor T cells was significantly larger in CSF than in PB. These data suggest that helper T cells play an important role in the early stages of VKH disease. sIL-2R and IL-6 levels were not elevated in CSF of patients with VKH disease. The level of sIL-2R in serum also was not elevated.

Adult↗