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Biomedical subjects

K Bando

Publications and source records attributed to K Bando.

At least 19 recordsLinked to original sources

Normoglycemia per se but not normoinsulinemia is responsible for suppressing endogenous insulin secretion after oral glucose load in NIDDM.

It is well known that intensive insulin treatment of non-insulin-dependent diabetics (NIDDM) suppresses endogenous insulin secretion and thereafter improves it. To determine whether 'peripheral normo-insulinemia' or 'normoglycemia' established by the treatment is responsible for this suppression, the following five experiments were conducted on 15 well-controlled non-obese NIDDM patients. Experiment 1: a 100 g oral glucose load (OGL) was performed and blood glucose was monitored by an artificial endocrine pancreas (AP). Experiment 2: a 100 g OGL was done and blood glucose was normalized by AP-controlled insulin infusion. Experiments 3 and 4: a 100 g OGL was conducted while 'hyperglycemia' seen in experiment 1 was mimicked by AP-controlled glucose infusion with pre-programmed insulin infusion at the same rates as those in experiment 2 ('normoinsulinemia') or at rates 1.5 times higher than those in experiment 2 ('relative hyperinsulinemia'), respectively. Experiment 5: a 40 g OGL was conducted while AP-controlled insulin and glucose infusions were administered to make the plasma insulin level lower than in experiment 2 ('hypoinsulinemia') and to mimic the normoglycemic profile observed in experiment 2, respectively. In experiments 3 and 4, neither 'normoinsulinemia' nor 'relative hyperinsulinemia' suppressed the increase in plasma C-peptide after a 100 g OGL. In experiment 5, where the plasma insulin level showed a significantly (P less than 0.05) lower level than in experiment 2 and glycemia was normalized, C-peptide did not show a significant rise after OGL. These results indicate that 'normoglycemia' rather than 'normoinsulinemia' attained during exogenous insulin therapy, is responsible for suppressing endogenous insulin secretion against orally administered glucose.

Blood Glucose

Lung transplantation at the University of Pittsburgh.

Lung transplantation appears to be a therapeutic alternative for selected patients with end-stage pulmonary vascular and/or parenchymal disease. The greatest impediment to transplantation remains the availability of donor organs. This has become more significant as additional transplant centers become operational. The primary cause of death has been infection, and this most frequently occurs in the early post-transplant period. Significant progress has been made in curbing the morbidity and mortality from bacterial pneumonia and CMV infection, and this is the primary reason for improved survival rates. If the recipient survives the initial hospital stay, the likelihood of survival at 5 years is approximately 80%. The primary long-term complication is obliterative bronchiolitis which is poorly understood and difficult to treat. Nevertheless, the improvement in survival provides impetus to refine and improve the procedure so that survival can reach that attained by recipients of other major organ allografts.

Academic Medical Centers

[A case of subfrontal schwannoma].

We encountered a rare case of subfrontal schwannoma. A 55-year-old woman had received resection of a left frontal tumor because of hyposmia, at the age of 28 years. On June 10, 1989, she was admitted with the chief complaint of progressive contraction of visual field. Neurologic examination revealed anosmia, impaired vision and concentric contraction of visual field. Fundoscopy showed optic atrophy. CT examination demonstrated a calcified mass of mixed density which was occupying her nasal cavity, ethmoid sinus and anterior skull base. The lesion was enhanced with contrast medium. MRI clearly depicted the extension of the lesion and a low signal intensity area in the left frontal lobe as a postoperative scar. Angiography showed hypovascularity. The tumor was totally removed by bifrontal craniotomy on August 22, 1989. Infiltration into the brain or compression of the optic nerve was not detected. The dura on the cranial base side was damaged and lost by infiltration of the tumor, normal olfactory bulb was not able to be identified, and the cribriform plate was broken. The anterior skull base was reconstituted by covering the dural defect with cadaveric dura and the bony defect with a pericranium. HE staining showed Antoni A&B types of schwannoma. Postoperative course was uneventful. In this case, it is most likely that a remnant of the tumor resected when she was 28 years old had developed subfrontal schwannoma a long time after the operation, although the histological type at that time was unknown. It is also possible that a primary tumor in the nasal cavity or paranasal sinus may have extended into the cranium.(ABSTRACT TRUNCATED AT 250 WORDS)

Craniotomy

Successful twenty-four-hour lung preservation with donor core cooling and leukocyte depletion in an orthotopic double lung transplantation model.

Donor core cooling with cardiopulmonary bypass is a valid method of clinical lung preservation. However, organ ischemia with this method is still limited to short-term intervals. Since circulating leukocytes participate in postischemic injury through the release of oxygen-derived free radicals, we examined whether leukocyte depletion by mechanical filtration could extend ischemic tolerance of the lung during preservation and subsequent double lung transplantation. Bovine donor lungs were preserved by donor core cooling (10 degrees to 15 degrees C) with cardiopulmonary bypass. Donor lungs were removed, stored in 4 degrees C donor blood for 24 hours, and transplanted. Graft function was studied for 6 hours after transplantation. Group 1 animals (n = 6) underwent standard cardiopulmonary bypass with whole blood for donor and recipient procedures. In group 2 (n = 6), leukocyte filters were incorporated into the cardiopulmonary bypass circuit in both donor and recipient operations. In group 2 recipient animals leukocyte counts decreased to 3% of mean baseline values and remained low during the experiment. Postischemic lung function (assessed by systemic arterial oxygenation, pulmonary artery pressure, pulmonary vascular resistance, airway pressure, lung water content, and end-point histologic characteristics) was significantly better preserved in the animals with leukocyte depletion. Leukocyte depletion by mechanical filtration in both donor and recipient improves the ischemic tolerance of the lung beyond that provided by donor core cooling alone, resulting in excellent lung function after 24 hours of ischemia.

Animals

Leukocyte depletion results in excellent heart-lung function after 12 hours of storage.

Extended preservation of the heart-lung block for 12 hours in a bovine model of heart-lung transplantation was achieved using donor core cooling, static hypothermic storage, and reperfusion on cardiopulmonary bypass with leukocyte-depleted (LD) blood. Orthotopic heart-lung transplantation was performed with (n = 4, LD group) or without (n = 4, control group) LD blood during cardiopulmonary bypass. Postoperative measurements of cardiopulmonary function were made at 2, 4, and 6 hours after reperfusion. Only 2 animals (50%) of the control group survived more than 2 hours, whereas all animals in the LD group survived the study period. Arterial oxygen tension on 100% oxygen was 535.63 +/- 64.96 mm Hg and 146.45 +/- 90.9 mm Hg in the LD and control groups, respectively, at 2 hours (p less than 0.5) and 524.3 +/- 73.32 and 147.9 +/- 255.67 mm Hg at 6 hours. Pulmonary artery systolic pressure-to-systemic pressure ratio was 0.49 +/- 0.08 and 0.62 +/- 0.35 at 2 and 6 hours in the LD group. Extravascular lung water was 17.81 +/- 0.02 mL/kg (control group) and 11.28 +/- 9.15 mL/kg (LD group) at 2 hours. At reperfusion, the mean neutrophil count was 27 +/- 27 and 764 +/- 635 x 10(9)/L in the LD and control groups, respectively. This novel approach of leukocyte depletion during reperfusion after heart-lung preservation resulted in excellent cardiac and pulmonary protection.

Animals

[The effect of aldioxa on the formation of gastritis induced with sodium hydroxide].

The effects of aldioxa and cetraxate hydrochloride on the formative process of gastritis induced with intragastric application of 2% sodium hydroxide were studied. Rats were given food including either aldioxa or cetraxate hydrochloride for 6 weeks after the sodium hydroxide application. After sacrifice, the stomachs were removed, and the gastric mucosa were observed macroscopically and histologically. Gastric mucosal injury was widely induced with sodium hydroxide, being histologically characterized by mucosal hypertrophy, cell infiltration and intestinal metaplasia. These lesions seem to be the early stage of chronic gastritis. The aldioxa group showed a decrease of mucosal hypertrophy and cell infiltration as compared with the control group. In the cetraxate hydrochloride group, the mucosal surface of white gray color and the mucosal bosselation were observed macroscopically. Histologically, these were found to be cell infiltration and cyst formation. Moreover, intestinal metaplasia occurred at high incidence in this group. These findings in the cetraxate hydrochloride group are recognized to be an aggravation of chronic gastritis. From the above results, it is suggested that aldioxa promotes good regeneration of mucosa and should be useful for the clinical therapy of chronic gastritis.

Allantoin

[Glomerular apolipoprotein B deposition in glomerular diseases].

In an attempt to elucidate the relationship between the progress of glomerular injury and abnormalities of lipid metabolism, we investigated glomerular deposition of apolipoprotein B (apo B) in renal biopsy specimens from 60 patients with glomerular diseases by indirect immunofluorescence using antihuman apo B-100 monoclonal antibody in comparison with clinical and histopathological findings. The patients were divided into 2 groups according to the intensity in staining of apo B in glomerulus (group A: negative or weakly positive; and group B: definitely positive). Staining of apo B in glomerulus was found in 37 patients (62%). The levels of serum total cholesterol, phospholipids, low density lipoprotein cholesterol and apo B in group B were significantly higher than in group A. The urinary protein excretion in group B was greater than that in group A. Group B was also shown to have a significantly decrease in renal function. Light microscopy revealed severe mesangial proliferation in patients with IgA nephropathy of group B. These findings suggested that glomerular apo B containing-lipoprotein deposition may play an important role in the progression of glomerular injury.

Adolescent

[Extended hypothermic heart-lung preservation system for cardiopulmonary preservation with retrograde coronary sinus perfusion and lung immersion].

One major restriction of clinical heart-lung transplantation has been the inability to provide extended hypothermic organ preservation. We examined whether core-cooling, retrograde heart perfusion and lung immersion could provide adequate cardiopulmonary preservation. Hence, donor dogs were placed on cardiopulmonary bypass, and rapidly cooled to 15 degrees C. Then heterotopic heart unilateral left lung transplantations were performed. In control group I (n = 5), hearts and lungs were harvested following core-cooling and cardioplegic arrest, and transplanted immediately. In experimental group II (n = 5), heart-lung blocks were similarly excised but stored at 4 degrees C for 12 hours and then transplanted. During preservation, the lungs were immersed in the extracellular solution. For the heart, non-recirculating retrograde coronary sinus perfusion was performed with oxygenated intracellular solution containing perfluorochemicals. Myocardial function determined by the ratio of end-systolic pressure to end-systolic dimension in the experimental group was similar to that in controls. Although pulmonary vascular resistance and extravascular lung water of the experimental group was higher than those in control group, arterial oxygenation was similar in both groups. Thus, extended heart-lung preservation with core-cooling, retrograde heart perfusion and lung immersion technique could be achieved for heart-lung transplantation.

Animals

Leukocyte depletion ameliorates free radical-mediated lung injury after cardiopulmonary bypass.

Activated leukocytes and oxygen free radicals have been implicated in the pathogenesis of lung injury associated with cardiopulmonary bypass. To determine whether leukocyte depletion could prevent this injury, we used a dog model simulating routine cardiac operations. Mongrel dogs (11 to 17 kg) were subjected to cardiopulmonary bypass with a bubble oxygenator and cooled to 27 degrees C. After aortic crossclamping and cardioplegic arrest for 90 minutes, control animals (n = 5) were rewarmed and weaned from bypass, and their condition was then stabilized for 90 minutes. Leukocyte-depleted animals (n = 5) had a leukocyte filter incorporated in the bypass circuit. During bypass, circulating leukocyte counts decreased by 60% in control dogs, and by 97% in leukocyte-depleted animals. Free radical generation (estimated by spectrophotometric assay of plasma conjugated dienes) was significantly reduced by leukocyte depletion during and after bypass. Total hemolytic complement activity and the titer of C5 decreased markedly immediately after the onset of bypass in both the control and leukocyte-depleted animals. Pulmonary function after bypass was better preserved in leukocyte-depleted animals. These data suggest that depletion of circulating leukocytes contributes to lung injury during cardiopulmonary bypass and is associated with increased oxygen radical activity, pulmonary edema, and vasoconstriction. Leukocyte depletion substantially reduced the pulmonary injury seen after cardiopulmonary bypass.

Animals

Oxygen-derived free radical damage in canine heart transplantation.

To study the role of free radical-induced myocardial injury during heart transplantation, five groups of dog hearts were orthotopically transplanted. Control group I and experimental groups II, III, and IV (each n = 8) were reperfused for 1 hr after 49 min of operational ischemia. Control group V (n = 4) remained ischemic for 90 min. In the three experimental groups, the free radical scavengers superoxide dismutase (10 mg/kg; group II), catalase (10 mg/kg; group III), or both (10 mg/kg each; group IV) were administered just before reperfusion and during reperfusion for 1 hr. The generation of free radicals, remained at low levels in all groups during ischemia, but significantly increased when groups I-IV were reperfused. This increase was also associated with an increase in creatinine kinase MB isoenzyme. In the experimental groups, free radical scavengers significantly inhibited the appearance of thiobarbituric acid reactive substances and the release of creatinine kinase MB isoenzyme during reperfusion (P less than 0.05). Regarding cardiac functions, 60 min after the termination of the cardiopulmonary bypass, a significant improvement was demonstrated in the treated groups (P less than 0.05). These results indicate that (1) the generation of oxygen free radicals occurs primarily during reperfusion, (2) both superoxide dismutase and catalase reduce production of free radicals during this time, and (3) combined administration did not provide a greater improvement in cardiac metabolic recovery. This study confirms the efficacy of free radical scavengers during heart transplantation.

Animals

Successful extended hypothermic cardiopulmonary preservation for heart-lung transplantation.

The inability to obtain sufficiently extended hypothermic organ preservation is a major restriction on clinical heart-lung transplantation. We used core cooling, nonrecirculating retrograde heart perfusion, and lung immersion with liposomal recombinant human superoxide dismutase in an attempt to provide effective 12-hour cardiopulmonary preservation. Donor dogs supported by cardiopulmonary bypass were rapidly cooled to 15 degrees C with cardioplegic arrest, and heterotopic heart and unilateral left lung transplantations were performed. In control dogs (n = 7), hearts and lungs, harvested after core cooling and cardioplegic arrest, were transplanted with a total mean ischemic time of 88 +/- 5 minutes. In group II (n = 7), heart-lung blocks were similarly excised but preserved at 4 degrees C for 12 hours (756 +/- 30 minutes) and then transplanted. During preservation, the lungs were immersed in hyperosmolar extracellular solution. For the heart, retrograde coronary sinus perfusion was performed with intracellular solution containing perfluorochemicals at a temperature of 4 degrees C and a rate of 30 ml/hr for 12 hours. In group III (n = 7), donor organs were similarly excised and preserved for 12 hours (726 +/- 39 minutes), except that liposomal recombinant human superoxide dismutase was administered during harvest, preservation, and reperfusion. Myocardial function, assessed by the ratio of end-systolic pressure to end-systolic dimension, after the 12-hour preservation period in both experimental groups was similar to that of the control group 4 and 6 hours after transplantation. The mean arterial oxygen capacity of the transplanted left lung during ventilation with an inspired oxygen concentration of 40% was also similar in each group. In contrast, the 12-hour preservation of pulmonary function assessed by pulmonary vascular resistance, the accumulation of extravascular lung water, and histologic evidence of alveolar wall injury, interstitial edema, and perivascular hemorrhage were significantly impaired in the absence of liposal recombinant human superoxide dismutase. These findings suggest that successful extended cardiopulmonary preservation for heart-lung transplantation is possible with core cooling, nonrecirculating retrograde heart perfusion, and hypothermic lung immersion incorporating liposomal recombinant human superoxide dismutase.

Animals

[High energy phosphates and mitochondrial respiratory function after 24 hours cardiac preservation--comparison between simple hypothermic immersion and continuous hypothermic perfusion].

Cardiac preservation is one of the most important step during heart transplantation. Prolonged preservation period is necessary to get the greater donor pool. To get safe prolonged preservation two methods, simple hypothermic immersion method (group A) and continuous hypothermic perfusion method (group B), were compared in this report by evaluating the myocardiac high energy phosphate level and mitochondrial respiratory function. The values of ATP, TAN and Energy charge were significantly higher in group B than group A (p less than 0.001). Mitochondrial respiratory function such as state 3 QO2, state 4 QO2, RCI and ADP/O also showed significantly higher values in group B than group A (p less than 0.001). These date indicate that continuous hypothermic perfusion method provides better preservation than simple hypothermic immersion method for 24 hours cardiac preservation.

Adenosine Triphosphate

Core-cooling, heart-perfusion, lung-immersion technique provides successful cardiopulmonary preservation for heart-lung transplantation.

Mongrel dogs underwent heterotopic heart-orthotopic left lung transplantation. In Group I (N = 6), donor organs procured following core cooling to 15 degrees C on cardiopulmonary bypass (CPB) with cardioplegic arrest were immediately transplanted. In Group II (N = 6), following cardioplegic arrest without CPB core-cooling, the pulmonary artery was flushed with modified Collins' solution. Heart-lung blocks were immersed in extracellular solution for 6 hours and then transplanted. In Groups III and IV (N = 6 each), following CPB core-cooling to 15 degrees C and cardioplegic arrest, the organ blocks were immersed in extracellular solution (Group III) and the heart was perfused with oxygenated extracellular solution (Group IV). Evaluation of lung function using differences in arterial oxygen tension between the left and right atria demonstrated no differences between groups. However, extravascular lung water and pulmonary vascular resistance were significantly elevated in Group II. Cardiac function assessed by the ratio of end-systolic pressure to end-systolic dimension was significantly better in Group IV than in Groups II and III. Thus, adequate 6-hour hypothermic cardiopulmonary preservation with core cooling plus heart perfusion can be achieved for heart-lung transplantation.

Animals

[A quantitative measurement of the cerebral infarct focus induced by arachidonate infusion and the relationship between measured values and stroke signs].

A method for measuring the organic infarct focus induced by arachidonate infusion into rat brain was devised, and the statistical relationship between the measured values and stroke signs in the rat was studied. By the infusion of arachidonate, a high incidence of cerebral infarction was found in the live rats with uniformly necrotized foci. The size of these foci (infarction rate) were measured by transcripting them to a graduated brain sheet. The relationship between the independent parameter of the infarction rate and the dependent parameter of stroke signs was fully analyzed by multidimensional quantification. Many animals showed no stroke signs despite having lesions (false negative). By contract, no animal without any lesion showed stroke signs (false positive). When each parameter of these signs were quantified and normalized, the stumbling and abnormal posture signs showed a wide range of values, relatively accurately reflecting the infarction degree. Moreover, the highest partial correlation ratio between the various parameters was found to be that between the stumbling and abnormal posture stroke signs. Thus, it may be said that the stumbling and the abnormal posture stroke signs can be considered relatively good parameters for evaluating the degree of an infarction. These parameters should be useful for the testing of anti-infarction drugs.

Animals