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Biomedical subjects

A Kawaguchi

Publications and source records attributed to A Kawaguchi.

At least 145 records · Page 8Linked to original sources
PubMed1989

Identification of cholesta-7,24-dien-3 beta-ol and desmosterol in hamster cauda epididymal spermatozoa.

The sterol composition of hamster cauda epididymal spermatozoa was remarkably different from that of several other mammalian spermatozoa. Desmosterol and cholesta-7,24-dien-3 beta-ol account for as much as 90% of the total sterols. Cholesterol and desmosterol are the major components of mouse cauda epididymal spermatozoa, and rabbit, boar and bull ejaculated spermatozoa. Cholesta-7,24-dien-3 beta-ol was not detected. Furthermore, cholesterol was the main sterol in hamster caput epididymal spermatozoa, while only a trace amount of desmosterol was detected and cholesta-7,24-dien-3 beta-ol was hardly detected at all. The sterol content of cauda and caput epididymal spermatozoa was 0.17 +/- 0.05 mumol/10(8) spermatozoa. During maturation, the desmosterol and cholesta-7,24-dien-3 beta-ol levels increase and the cholesterol level decreases. Cholesta-7,24-dien-3 beta-ol appears as a sterol in mature spermatozoa and seems to be a characteristic sterol of hamster cauda epididymal spermatozoa.

Animals↗
PubMed1989

Binding site of cerulenin in fatty acid synthetase.

An antibiotic cerulenin, (2R, 3S)-2,3-epoxy-4-oxo-7,10-trans,trans- dodecadienamide, irreversibly inhibits fatty acid synthetase from Saccharomyces cerevisiae. Three moles of cerulenin were bound to 1 mol of the enzyme with concomitant loss of its activity. Pretreatment of the enzyme with iodoacetamide reduced the amount of cerulenin bound to the enzyme. Since iodoacetamide is known to specifically bind to the cysteine residue on the condensing reaction domain, cerulenin is considered to bind to the same domain. Tryptic digestion of the [3H] cerulenin-treated enzyme gave a radioactive peptide; its amino acid composition was Asx 1, Thr 1, Ser 1, Glx 2, Pro 1, Gly 1, Ala 1, Val 1, Ile 1, and Leu 2. This composition included all the amino acids of the condensing reaction site (Thr-Pro-Val-Gly-Ala-Cys) previously reported by Kresze et al. (Eur. J. Biochem., 79, 181 [1977] except for Cys. When the enzyme was treated with [3H]cerulenin and digested successively with trypsin and carboxypeptidase P, a [3H] cerulenin-cysteine adduct was isolated as the sole product. This was identified with the adduct chemically synthesized from non-labeled cerulenin and cysteine, and its structure was elucidated by 1H-, 13C-NMR, and fast atom bombardment mass spectrometry. These results indicate that cerulenin, forming a hydroxylactam ring, reacts at its epoxide carbon (C-2 position) with the SH-group of the cysteine residue in the condensing reaction domain of yeast fatty acid synthetase.

Amino Acids↗
PubMed1989

[Study of small hepatocellular carcinomas].

In order to evaluate the factors affecting patient survival, 32 patients with a solitary hepatocellular carcinoma (HCC) smaller than 5 cm have been studied. Most patients were diagnosed as having a HCC during the periodic follow-up examinations for their underlying liver disease. For HCCs smaller than 2 cm, ultrasonography demonstrated the highest detection rate compared with CT and angiography. In patients with tumors larger than 2 cm, a portal vein thrombus and/or satellite tumors were frequently recognized, resulting in a lower patient survival rate when compared to those with a smaller HCC. Results have indicated that early detection of such tumors without a portal vein thrombus and/or a satellite tumor, and an adequate hepatic resection, such as segmentectomy or subsegmentectomy, are most important factors HCC patient survival.

Adult↗
PubMed1989

Heart and unilateral lung transplantation in patients with end-stage cardiopulmonary disease and previous thoracic operations.

Orthotopic en bloc transplantation of the heart and one lung has been done in two patients with end-stage cardiopulmonary disease and a prior thoracic operation. The first patient had undergone right pulmonary thromboembolectomy with caval ligation 5 years earlier, and the second had had left lower lobectomy for bronchiectasis 15 years before the heart and contralateral lung transplantation. Surgical procedures followed the techniques that had been developed in animals. Transplantation of the unoperated contralateral lung made it possible to avoid dissection in the obliterated pleural space and to minimize bleeding, which simplified the procedure considerably. Dramatic reduction in pulmonary artery pressure and improved respiratory function allowed both patients to be weaned from cardiopulmonary bypass without problems. Although the first patient died of liver and renal failure soon after the operation, an intact cough reflex facilitated recovery in the second patient, who has been discharged with essentially normal respiratory function. This report describes heart and unilateral lung transplantation as a procedure of choice for patients with extensive pleural adhesions that made total cardiopulmonary replacement unfeasible.

Adult↗
PubMed1989

Simplified rat lung transplantation using a cuff technique.

A cuff technique is introduced to anastomose pulmonary vein and pulmonary artery in rat lung transplantation. In 11 consecutive cases, the average graft ischemic time was 13.5 +/- 2.0 minutes and operating time 100.7 +/- 4.8 minutes: The time for ischemia was less than one third of previous reports and the time for operation one half of previous reports. Excluding two operative deaths, the survival rate was 88.8% (8/9) on postoperative day 11, when contralateral pneumonectomy revealed excellent graft function supporting the oxygenation of the animals.

Anastomosis, Surgical↗
PubMed1989

[Subclavian flap aortoplasty with preservation of arterial blood flow to the left arm for coarctation repair--report of 2 cases].

Two infants with coarctation of the aorta were successfully repaired by the modified method of subclavian flap aortoplasty with preservation of arterial blood flow to the left arm. The left subclavian artery was detached from the aorta at its origin, opened longitudinally in its posterior wall and sutured over the coarctation site. Widening of the stenosis and preserving of the blood flow to the left arm were obtained. This operative technique seems advantageous without complications induced by sacrificing the continuity of the subclavian artery, reserving the advantages of the former subclavian flap aortoplasty.

Aortic Coarctation↗
PubMed1989

Hemodynamic characteristics of the Jarvik-7 total artificial heart.

To identify the optimal means of artificial circulation, driving controls and resultant hemodynamics were correlated with clinical outcomes in 37 Jarvik-7 recipients up to 72 hours after implantation. When patients with subsequent transplantation (n = 16) were compared with those who died on the Jarvik-7 heart (n = 21), there were no significant differences in total artificial heart driving mode such as frequency, ventricular driving pressures, systolic-diastolic ratio, or vacuum use, nor were there any differences in the hemodynamics achieved, such as device output (cardiac output) or atrial filling pressures, throughout the observation. However, improvements of other organ functions, especially kidney and liver, were remarkable in that transplant patients immediately experienced increased urine output and reversal of secondary organ dysfunction. The nontransplant group failed to diurese and continued to deteriorate despite similar hemodynamics. When a smaller model of the Jarvik-7 (volume of 70 ml, n = 18) was compared with the standard model (volume of 100 ml, n = 19), again there were no significant differences except that ventricular stroke volume was consistently less for the 70-ml model. Because of a slightly higher heart rate in the smaller model, device output did not differ between recipients of the two types. The results suggest that once successfully implanted, the Jarvik-7 provides adequate perfusion without associated mortality from circulatory failure, regardless of the size of the ventricle. Recovery from other organ failure appears to be independent of postimplant hemodynamics, a phenomenon that suggests the importance of preimplant status and patient selection.

Adult↗
PubMed1989

Cardiac transplant recipients with preoperative pulmonary hypertension. Evolution of pulmonary hemodynamics and surgical options.

Among 48 consecutive patients with pretransplant pulmonary vascular resistance (PVR) greater than 4 Wood units, 38 patients underwent orthotopic heart replacement (OHT), and the remaining 10 received a graft in a heterotopic position (HHT). The OHT recipients were smaller (63 vs. 73 kg, p less than 0.05) and received a larger donor heart (donor-recipient, 109% vs. 79%, p less than 0.001) with a shorter graft ischemic time (108 vs. 139 minutes, p less than 0.05) than HHT recipients, reflecting patient selection and surgical complexity. Comparison between the hospital survivors and nonsurvivors identified the selection of HHT and graft ischemic time in excess of 150 minutes as potent risk factors. Immediately after transplantation, pulmonary artery (PA) pressures dropped to almost one half of preoperative values regardless of the mode of transplantation. Within the next 24 hours, however, the OHT group required lower doses of inotropes, had lower left atrial pressure (12 vs. 16 mm Hg, p less than 0.05), and were more frequently extubated (58% vs. 10%, p less than 0.01). Catheterization at 10 days revealed a doubled cardiac index and a dramatic reduction in PVR for both groups. The higher the preoperative PVR value, the more substantial the reduction observed, resulting in normalization of PVR for all survivors. The incidence of early graft failure was similar between the groups, but HHT recipients frequently developed pulmonary complications and infection, resulting in a 30% hospital survival in contrast to 71% in OHT recipients (p less than 0.05). The results suggest that transplant candidates with pulmonary hypertension might better be treated by OHT with an oversized, on-site, viable donor heart than by HHT.

Adult↗
PubMed1989

Factors affecting survival after heterotopic heart transplantation.

In an attempt to identify the factors that influence survival after heterotopic heart transplantation, 42 consecutive recipients of heterotopic heart transplant were reviewed. Preoperative pulmonary artery pressures, pulmonary vascular resistance, and donor age significantly differed between hospital survivors and nonsurvivors. Postoperative survival analysis between pairs of groups of patients divided by each of these variables disclosed a significant difference, which confirmed the effects of these variables on survival. Evolution of pulmonary hemodynamics was compared between patients with preoperative pulmonary artery diastolic pressure greater than 25 mm Hg (pulmonary hypertension; n = 22) or less than 25 mm Hg (nonpulmonary hypertension; n = 20). Despite marked differences in preoperative pulmonary hemodynamics, pulmonary artery pressures were dramatically reduced immediately after transplantation, and pulmonary vascular resistance diminished to upper normal limits at 10 days when there were no longer differences in pulmonary vascular resistance between the two groups. Immediate deaths were related to left ventricular failure, and the incidence was similar between the groups. Despite such normalization of pulmonary hemodynamics, patients with preoperative pulmonary hypertension experienced more frequent ventricular fibrillation, required longer respiratory support, and developed lethal pulmonary or systemic infection, which resulted in a 32% (7/22) hospital survival rate compared with 90% (18/20) in patients without pulmonary hypertension. Despite the dramatic improvement in pulmonary hemodynamics, heterotopic heart failed to demonstrate the expected advantages because of frequent pulmonary complications and infection, which resulted in failure to improve the prognosis of patients with preoperative pulmonary hypertension.

Actuarial Analysis↗
PubMed1988

[Studies of 5-FU concentrations associated with microangiography in colorectal cancer tissue].

In order to elucidate the effect of supplying vessels on 5-FU distribution within a tumor, the correlation between 5-FU tissue concentration and tumor microangiography was examined in 31 patients with colorectal cancer after administration of 5-FU (500 mg/day for 3 days). The 5-FU concentration at the tumor margin was significantly higher than that in the other two tissue areas (p less than 0.05). A low 5-FU concentration was noted in the central region of ulcerative cancer showing vertical invasion with vascular disarray and/or histological necrotic foci. This type of tumor also showed a low RNA index by flow cytometry. The present study indicates that the vascular change and vascular pattern of a tumor may be a major contributing factor to 5-FU transfer from the blood circulation into a tumor.

Adult↗
PubMed1987

In vitro effect of a thymic epithelial culture supernate or thymosin fraction 5 on rabbit platelet aggregation and intracellular cyclic AMP levels.

Supernates of thymic epithelial cell culture (STEC) strongly inhibit aggregation induced by addition of adenosine diphosphate (ADP: 1 microM) or thrombin (0.5 unit per ml) to washed platelet suspensions and accelerated the restoration from ADP-triggered aggregation. At the same time, STEC increased the level of platelet adenosine 3',5'-cyclic monophosphate (cyclic AMP) in a dose-dependent manner. Depending on the concentration used, thymosin fraction 5 increased the level of intracellular cyclic AMP ranging between 5 and 100 micrograms per ml, as well as inhibiting ADP-induced platelet aggregation. The activities of both STEC and thymosin fraction 5 were found to act exclusively on cyclic AMP phosphodiesterase activity in platelets. In contrast the supernates from Chang, HeLa, or HCC-M cells did not affect platelet aggregation induced by ADP, but slightly increased the cyclic AMP level (Chang, HeLa). Within 2 min after the treatment with STEC, more than 50% of the maximum inhibitory activity on platelet aggregation and increases in intracellular cyclic AMP were observed. These activities disappeared following STEC treatment with pronase E. STEC activity was found predominantly in the 1,000-50,000-dalton fractions. These activities were not altered when STEC was treated by adenosine deaminase. The level of prostaglandin E (PGE) derivatives in STEC was about two times that found in the control culture medium. These data suggest that the biological activity of STEC in the platelets might be attributed to thymosinlike polypeptides and PGE1.

Adenosine Deaminase↗
PubMed1987

Urinary thromboxane excretion in cardiac allograft rejection in immunosuppressed rats.

Increased urinary excretion of immunoreactive thromboxane B2 (iTxB2) was found to have a high predictive value, with high sensitivity as an indicator of cardiac allograft rejection in both the immunosuppressed and nonimmunosuppressed rat. In the animals receiving an allograft, urinary iTxB2 excretion significantly increased prior to the onset of rejection, remained elevated, and returned to basal values following completion of the episode. Urinary iTxB2 remained at baseline values in the control animals. The association between rejection and iTxB2 excretion was preserved regardless of the presence or nature of immunosuppression. Urinary iTxB2 excretion increased significantly prior to the reduction of graft beat or histological evidence of rejection. Evaluation of urinary iTxB2 monitoring as a noninvasive indicator for surveillance of clinical cardiac allograft rejection appears to be warranted.

Animals↗
PubMed1986

Enzymatic bases for the fatty acid positioning in phospholipids of Brevibacterium ammoniagenes.

Positional distribution of fatty acids in phospholipids from Brevibacterium ammoniagenes was analyzed to find that phosphatidylethanolamine consisted mainly of 1-saturated acyl 2-unsaturated acyl species while phosphatidylglycerol consisted mainly of 1-unsaturated acyl 2-saturated acyl species. Three acyltransferase systems were characterized in a membrane preparation--the acylations of glycerophosphate, 1-acyl-glycerophosphate, and 2-acyl-glycerophosphate--which appeared to be catalyzed by different enzymes. The distribution of fatty acids in the phosphatidylethanolamine molecule was not correlated simply with the specificities of these enzymes, but the relatively high specificity for palmitoyl-CoA of the glycerophosphate acyltransferase system to form 2-acyl-glycerophosphate, followed the relatively high specificity for oleoyl-CoA of the 2-acyl-glycerophosphate acyltransferase system, provided a basis for producing the major molecular species of phosphatidylglycerol.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗