Biomedical subjects

J Utoh

Publications and source records attributed to J Utoh.

63 records · Page 4Linked to original sources

PubMed1988

Effect of surgery on neutrophil functions, superoxide and leukotriene production.

Perioperative changes of neutrophil function were investigated in 28 patients who underwent major surgery, particularly focusing on the potential capacity for superoxide and leukotriene production, which seem to be important in host defence. The superoxide-producing capacity of neutrophils, which was examined using N-formyl-peptide or phorbol myristate acetate as an attractant, significantly decreased postoperatively to 55 and 69 per cent of the pre-operative values, respectively. The leukotriene-producing capacity of neutrophils, which was stimulated with calcium ionophore A23187 in the presence of arachidonic acid, significantly changed postoperatively. The leukotriene B4 (LTB4) production increased together with an increment of production of 6-trans 6-trans LTB4, however, increased postoperatively to 1.2 times the (LTC4) production decreased postoperatively. The total production of leukotriene A4 (LTA4) metabolites consisting of LTB4, LTC4, and 6-trans LTB4, however, increased postoperatively to 1.2 times the pre-operative values. This indicates that neutrophils in the postoperative period have a higher capacity for LTA4 production but a lower capacity for superoxide production than those in the pre-operative period.

Adult↗

PubMed1988

Complement conversion and leukocyte kinetics in open heart surgery.

Complement conversions and a pulmonary leukocyte sequestration were observed during cardiopulmonary bypass (CPB) in all of twenty patients who received open heart surgery. A systemic neutropenia was initially observed in the early phase of CPB, and it subsequently turned into a systemic neutrocytosis during the late phase of it. A significant leukocyte sequestration was found in the pulmonary circulation during CPB coincidently with the systemic neutropenia. The contribution of the transpulmonary sequestration to the leukopenia was major, being as high as 80 per cent. Plasma C3, C4, and CH50 levels rapidly decreased following the commencement of CPB. Alterations of the C3 molecule in the patients' plasma were demonstrated using the immunoblotting method. The appearances of C3a and C3b with the apparent molecular weights of 10,000 and 170,000 respectively, might be evidence of the complement activation during CPB. Another type of alteration in the C3 molecule was observed in the generation of a new fragment with the apparent molecular weight of 14,000. The appearance of this fragment, which did not share common epitopes with C3a, might suggest the consumption of complement components during CPB, unrelated to the activation of the complement systems.

Adult↗

PubMed1986

Surgery of hepatoma with intracavitary cardiac extension.

A case of primary liver carcinoma with intracavitary cardiac extension is presented. A 36-year-old female was admitted to our surgical clinic with dyspnea and generalized edema. Echocardiography and superior vena cavography demonstrated a large filling defect in the right atrium. After a diagnosis of acute cardiac failure due to an intracardiac tumor, the patient was operated upon immediately. A right atriotomy exposed a large yellow mass within the right atrium, which was not adherent to the atrial wall. The mass was in continuity with similar material in the inferior vena cava and right hepatic vein. With a suspicion of hepatic malignancy, the atrial tumor was removed, and debulking of the mass in the inferior vena cava and right hepatic vein was performed. A postoperative histological examination of the tumor showed hepatocellular carcinoma. Her postoperative course was uneventful, and she was discharged from the hospital. Intracardiac extension of hepatoma is rarely encountered. In this clinical setting, long-term survival cannot be anticipated from any surgery, but palliative clearing of the atrium and inferior vena cava may be of value in preventing cardiac arrest causing sudden death.

Adult↗

PubMedDate not supplied

Effects of mechanical ventilation and spontaneous respiration on hemodynamics in calves with total artificial hearts.

The effects of respiration on hemodynamics were evaluated in four Holstein calves with total artificial hearts (TAH). The electrohydraulic actuated E4T-TAH has a continuously reciprocating actuator packaged between two alternately ejecting blood pumps that passively fill. The hemodynamic parameters (right atrial pressure [RAP], left atrial pressure [LAP], pulmonary artery pressure [PAP], aortic pressure [AoP]), and right and left pump filling (Rt% fill and Lt% fill) were measured when the animal was intubated and mechanically ventilated. These measurements were repeated with spontaneous respiration after the animal was extubated. With mechanical ventilation, LAP, PAP, and AoP were significantly higher during inspiration than during expiration. However, RAP during inspiration was slightly lower than that during expiration. The Rt% fill during inspiration was significantly lower than during expiration, but Lt% fill during inspiration was significantly higher than during expiration. During spontaneous respiration, these changes were opposite to those observed during mechanical ventilation. That mechanical ventilation generates positive intrathoracic pressure during inspiration, but spontaneous respiration generates negative pressure may explain these results. The change in venous return to the right atrium caused the change in RAP to be opposite in direction to that of the other pressures.

Animals↗

PubMedDate not supplied

Antigenicity of cryopreserved arterial allografts: comparison with fresh and glutaraldehyde treated grafts.

The use of cryopreserved aortic allografts in cardiovascular surgery is widespread and has resulted in excellent outcomes. However, it is controversial whether cryopreservation suppresses the antigenicity of tissue. We designed experimental models to study whether the cryopreservation process alters antigenicity in comparison with that found in fresh and glutaraldehyde treated tissues. Fresh, cryopreserved, and glutaraldehyde treated thoracic aorta from Brown Norway rats were subcutaneously implanted into Lewis rats. Inflammatory cells infiltrating around the grafts were measured on days 7, 14, 28, and 56 after implantation. The glutaraldehyde treated grafts showed significantly less infiltration than the fresh or cryopreserved grafts (p < 0.005). No significant difference was detected between the fresh and cryopreserved grafts. Another study examined the effect of modifications of the aortic allograft on subsequent allogeneic skin graft antigenicity. Subcutaneous implantation of fresh, cryopreserved, and glutaraldehyde treated aortic grafts from Brown Norway into Lewis rats resulted in subsequent skin graft rejection at 4.4+/-0.7, 5.1+/-0.8, and 6.6+/-2.1 days, respectively. There was no significant difference between the fresh and cryopreserved groups; whereas skin grafts in the glutaraldehyde group survived longer than those in the cryopreserved group. These results indicate that cryopreservation had no significant influence on antigenic suppression of arterial allografts.

Animals↗

PubMedDate not supplied

Pretreatment of a Dacron graft with tissue factor pathway inhibitor decreases thrombogenicity and neointimal thickness: a preliminary animal study.

The purpose of this study was to evaluate the effects of locally applied TFPI on the reduction of neointimal thickness in Dacron grafts. Seven millimeter internal diameter 5 cm lengths of albumin coated knitted Dacron grafts were interposed in the infrarenal aorta in 14 mongrel dogs. Before implantation, the grafts were immersed in saline solution containing 200 microg/ml of TFPI (TFPI group, n = 7) or 100 IU/ml of heparin (control group, n = 7) for 15 minutes at room temperature. Three months after implantation, neointimal thickness and percentage of graft stenosis were measured by computerized planimetry. All grafts were patent 3 months after implantation. Thrombus was found in one graft in the TFPI group, but observed in three of seven control grafts. Neointimal thickness in the TFPI group was significantly smaller than that in the control group (mean +/- SD, 0.26 +/- 0.1 mm vs. 0.57 +/- 0.15 mm, p < 0.001). Percentage of graft stenosis was significantly lower in the TFPI group than in the control group (13.4 +/- 5.3% vs. 26.9 +/- 7.0%, p < 0.001). Scanning electron micrographs showed that the neointima of TFPI treated grafts were completely covered by endothelial cells. The present results indicate that locally applied TFPI reduces thrombogenicity and neointimal thickness in albumin coated knitted Dacron grafts.

Animals↗

PubMedDate not supplied

Effects of heat on fragility and morphology of human and calf erythrocytes.

It is important to know the species differences when data from animal experiments are interpreted for human application. This in vitro study focused on the effects of heat, a major concern in mechanically actuated artificial heart development, on the physiology of human and calf erythrocytes (RBC). RBC from calves and healthy human donors were incubated at 25, 37, 46, 48, 50, or 52 degrees C for 1 h. Osmotic fragility was tested and morphological changes were then observed by scanning electron microscopy. The osmotic fragility of human and calf RBC increased at and above 50 degrees C. After incubation at 50 degrees C, 6% of human and 1% of calf RBC hemolyzed. Changes in surface morphology, which included spherocytic or echinocytic forms, were observed in 97% of human and 19% of calf RBC after incubation at 50 degrees C. In conclusion, human RBC showed greater changes in osmotic fragility and morphology at and above 50 degrees C. These changes, however, were not observed in either species after 1 h incubation at 46 degrees C.

Analysis of Variance↗

PubMedDate not supplied

Effect of oral and intravenous diltiazem on whole blood platelet aggregability.

Diltiazem, a calcium channel blocker, is known to suppress platelet function in vitro. However, its in vivo effects on platelets have been controversial. The effect of diltiazem on both human and calf platelets was studied using impedance whole-blood aggregometry. In vitro, platelet aggregation induced by ADP (5 microM) or collagen (1 micrograms/ml) was significantly suppressed by 0.1 to 1.0 mM (45 to 450 micrograms/ml) of diltiazem in both species. In calves weighting 70 to 90 kg, platelet aggregability did not change after the oral administration of 180 mg diltiazem. In this condition, diltiazem was not detected in plasma samples. Intravenous injection of 0.5 mg/kg diltiazem also did not significantly alter the aggregability, although the PR interval on the ECG elongated (40 msec, p < .05), mean arterial pressure dropped (14 mmHg, p < .05), and diltiazem was readily detected in plasma (199 ng/ml, 0.4 microM). In conclusion, platelet aggregability is not altered by a clinical dosage of diltiazem that is sufficient to induce hemodynamic changes with therapeutic plasma concentrations.

Administration, Oral↗

PubMedDate not supplied

Perioperative alteration of neutrophil functions after open heart and other major surgeries. A comparative study.

The prolonged effects of cardiopulmonary bypass on neutrophil functions, as indicated by the capacity to produce superoxide and leukotrienes, were examined on the first postoperative day in ten patients who underwent open heart surgery and ten who underwent other major surgery. The superoxide and leukotriene C4 producing capacities of the neutrophils were significantly decreased postoperatively in both groups. The leukotriene B4 producing capacity, by contrast, was significantly increased postoperatively. However, there was no significant difference in values between the two groups in the pre- and postoperative periods. In both groups, neutrophil functions were significantly altered on the first postoperative day, but no specific alteration due to open heart surgery was observed.

Cardiac Surgical Procedures↗