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Biomedical subjects

K Dohi

Publications and source records attributed to K Dohi.

At least 217 records · Page 12Linked to original sources
PubMed1998

Hepatic resection for cavernous hemangiomas of the liver.

In this report, we evaluate the indications of, and present our recent strategy for, cavernous hemangioma of the liver. Seven patients with cavernous hemangiomas of the liver, who underwent hepatic resection were enrolled in this study. The lesions were located in the right lobe in 3 patients, the left lobe in 2, and in both the right and left lobes in 2. The longest diameter of the lesions ranged from 1.4 to 14.5 cm (mean, 8.2 cm). The indications for hepatic resection were symptomatic lesions in 3 patients, lesions suspected to be hepatocellular carcinoma in 2, and symptomatic and growing lesions during follow-up in 2. Right lobectomy was performed in 2 patients, left lobectomy with caudate lobectomy in 1 patient, and minor hepatic resection in the other 4 patients. One of the patients who underwent minor hepatic resection had recently received laparoscopy-assisted hepatic resection and one of the three patients who received transfusion during surgery was given an autotransfusion. There were no mortality, and morbidity was minimal. In conclusion, hepatic resection, including laparoscopy-assisted procedures, was considered a safe treatment. Hepatic resection for cavernous hemangioma should be performed only in patients with moderate to severe symptoms, complicated lesions or both, because most benign lesions have a good natural course. Furthermore, in the future, less invasive surgical procedures should be used whenever possible to treat these benign liver tumors.

Digestive System Surgical Procedures↗
PubMed1998

Percutaneous microwave coagulation therapy for hepatocellular carcinoma.

We evaluated the efficacy of percutaneous microwave coagulation therapy (PMCT) as compared with hepatectomy in 19 patients with hepatocellular carcinoma (HCC). In 6 patients with tumors more than 3 cm in diameter, coagulation was inadequate after a single session of PMCT. Patients with multiple tumors had recurrence within 1 year. For single tumors 3 cm or less in diameter, the therapeutic effectiveness of PMCT was comparable to that of hepatectomy in cumulative survival and cancer-free survival rates. We conclude that PMCT should be used in the initial treatment of HCC only in patients with single tumors of up to 3 cm in diameter. Surgical removal is recommended for tumors of more than 3 cm in diameter.

Adult↗
PubMed1998

A surgically treated long-term survivor of hepatocellular carcinoma with tumor thrombi in the trunk of the portal vein.

Prognosis of hepatocellular carcinoma (HCC) patients with tumor thrombi (TT) in the trunk of the portal vein (PV) has been extremely poor. There have been few reports of long-term survivors with such an advanced condition. In this article, the case of a 62-year-old woman of HCC, who survived for 6 years and 9 months after an operation, with TT in the trunk of the PV is described. The patient not only had a primary tumor of 4 cm in diameter with TT but also multiple intrahepatic metastases in the bilateral lobe of the liver. A palliative lateral segmentectomy with tumor thrombectomy through the incised left first branch of the PV was performed. Moreover, an intraoperative ethanol injection for residual intrahepatic metastatic tumors was performed subsequently. Hepatic arterial infusion of anti-cancer drug with Lipiodol, intraportal continuous infusion of 5-FU and percutaneous ethanol injection therapy were performed suitably during the follow-up periods. The patient survived for 6 years and 9 months after operation and died of hepatic insufficiency with cancer. In this case a patient who suffered from HCC with TT in the trunk of the PV was successfully treated by multimodality procedures including hepatic resection with tumor thrombectomy.

Antineoplastic Agents↗
PubMed1998

Laparoscopy-assisted hepatectomy for a large tumor of the liver.

We performed a laparoscopy-assisted hepatectomy on a 52-year-old woman with a large hepatic cavernous hemangioma (longest diameter, 8.5 cm). With the use of Pringle's maneuver, the left lateral segment of the liver was resected with a Cavitron ultrasonic surgical aspirator (CUSA) while lifting the abdominal wall. Postoperative hepatic dysfunction was mild and transient, resolving spontaneously early after surgery. We intend to expand the indications of this minimally invasive procedure for hepatic resection.

Female↗
PubMed1997

In vitro and in vivo evidence for high frequency of I-Ab-reactive CD4+ T cells in HLA-DQ or HLA-DRA transgenic mice lacking endogenous MHC class I and/or class II expression.

Although T cells are educated to recognize foreign antigenic peptides in the context of self MHC molecules during their development in the thymus, peripheral T cells also recognize allo- and xeno-MHC molecules. The lower frequency of xeno-MHC-reactive T cells than that of allo-MHC-reactive T cells is often explained by the difference in the degree of homology between xeno- or allo-MHC and self MHC molecules, as well as by the species barrier of the molecules involved in immune recognition. To distinguish these two possibilities, we estimated the frequency of I-Ab-reactive CD4+ T cells selected by HLA-DQ or DR alpha E beta b molecules, using HLA-DQ6 and HLA-DRA transgenic C57BL/6 (B6) mice lacking endogenous MHC class I and/or class II molecules (DQ6A0/0 and DR alpha 30A0/0 beta 20/0). CD4+ lymph node T cells from DQ6A0/0 and DR alpha 30A0/0 beta 20/0 showed the strong proliferative response to I-Ab molecules. In addition, DQ6A0/0 and DR alpha 30A0/0 beta 20/0 rejected the skin graft from mice expressing I-Ab molecules irrespective of MHC class I expression, indicating that the CD4+ T cells recognizing I-Ab molecules are directly involved in this rejection. The estimated frequency of I-Ab-reactive CD4(+)CD8- thymocytes in DR alpha 30A0/0 beta 20/0 and DQ6A0/0 was comparable with that observed in the MHC class II-disparate strains. Our findings thus indicate that CD4+ T cells selected to mature on xeno-MHC class II molecules such as HLA-DQ6 or DR alpha E beta b, when these molecules are expressed in mice, recognize I-Ab molecules as allo-MHC class II, despite the less structural homology.

Animals↗
PubMed1997

Mechanism of cardiac involvement in the WBN/Kob rat.

The cardiac characteristics of the WBN/Kob rat resemble those of rats with catecholamine-induced myocarditis. To determine the etiology of these WBN cardiac characteristics, we assessed the number and affinity of beta-adrenergic receptors, and investigated adenylate cyclase activity, the cardiac myocyte cyclic adenosine monophosphate (cAMP) concentration and the activity of guanosine triphosphate (GTP)-binding protein in 3-month-old WBN/Kob rats. Age-matched Wistar rats served as controls. The mean number of beta-adrenergic receptors was similar in WBN/Kob and Wistar rats (28.0+/-9.1 v 28.3+/-8.9 fmol/mg protein), and there was no significant difference in beta-adrenergic receptor affinity between groups (1.09+/-0.54 v 1.26+/-0.60 nM). The mean cAMP concentration in cardiac myocytes was significantly higher in WBN/Kob rats than in Wistar rats 1975.6+/-247.8 v 344.9+/-83.6 pmol/g wet tissue), (P=0.0112) as was adenylate cyclase activity (33.61+/-8.32 v 24.3+/-12.78 pmol/mg/min), (P=0.0174). The activity of GTP-binding protein was significantly higher in WBN/Kob rats than in Wistar rats. After a beta-agonist binds to a beta-adrenergic receptor, activated adenylate cyclase produces cAMP in myocytes, which in turn opens the Ca2+ channel, leading to an influx of Ca2+ into myocytes. Our results suggest that the increase in adenylate cyclase activity in WBN/Kob rats have led to an increase in the cAMP concentration in myocytes. This process may have resulted in excessive beta-adrenergic activity due to high activity of GTP binding protein in WBN/Kob rats, which may explain the hypersensitivity of WBN/Kob rats to isoproterenol and the development of catecholamine-induced myocarditis.

Adenylyl Cyclases↗
PubMed1997

Effect of antileukocyte adhesion molecule antibodies, nitric oxide synthase inhibitor, and corticosteroids on endotoxin shock in mice.

We compared the therapeutic effects of anti-leukocyte adhesion molecule antibodies (mAbs), a nitric oxide (NO) synthase inhibitor (monomethyl-L-arginine, NMLA), and methylprednisolone (MP) on experimental endotoxin-induced shock in mice. Lipopolysaccharide (LPS, 30 mg/kg) was administered to ICR mice intraperitoneally, While 1 mg/kg mAb, 5-20 mg/kg NMLA, or 30 mg/kg MP was administered intravenously. The placebo group received phosphate-buffered saline. The survival rate of the placebo group 48 h after LPS injection was 36%. The administration of anti-CD11a, anti-CD18, anti-lectin cell adhesion molecule-1 (anti-LECAM-1), and MP increased the survival rate to 70, 62, 64, and 100%, respectively; however, NMLA had no significant effect. A FACS analysis revealed that the CD18 expression of granulocytes increased 12-fold within 30 min after LPS administration. MP significantly suppressed its expression. The plasma level of nitrate/nitrite increased from 20 to 260 and 1000 microM 4 and 16 h, respectively, 20 mg/kg NMLA abolished NO production at 4 h, while MP inhibited it for up to 16 h. The hepatic malondialdehyde level increased from 0.50 to 2.46 nmol/mg protein at 4 h. Administration of anti-CD18 and MP reduced the level to 1.80 and 1.41 nmol/mg protein, respectively, whereas NMLA did not affect it. The mAbs and MP were concluded to be useful agents for endotoxin shock. The abolition of NO production had little influence on the hepatic cellular injury associated with endotoxemia.

Animals↗
PubMed1997

Inflammatory fibroid polyp of the ileum with the appearance of a Borrmann type II lesion, caused by colostomy irrigation: report of a case.

Inflammatory fibroid polyps (IFPs) are rarely found in the gastrointestinal tract. The majority of IFPs are sessile-pedunculated or pedunculated polypoid lesions, whereas a polyp presenting like a Borrmann type II lesion is extremely unusual. This report describes the case of a 74-year-old man with a history of intussusception, in whom a preoperative diagnosis of a cecal tumor of the ileocecal valve was made. A laparotomy subsequently revealed a lesion similar to a Borrmann type II tumor located 15 cm above the ileocecal valve, but not at the valve. The lesion was diagnosed as an IFP which had been caused by repeated colostomy irrigation. The aim of the present report is to draw attention to this entity, which should be included in the differential diagnosis of intussusception and small bowel obstruction.

Aged↗
PubMed1997

Inhibition of warm ischemic injury to rat liver, pancreas, and heart grafts by controlling the nutritional status of both donor and recipient.

In this study, we tested the effect of donor fasting with or without the use of an essential fatty acids deficiency (EFAD) diet in the recipient using rat heart, pancreas, and liver transplant models. We then compared the survivals, tumor necrosis factor alpha (TNF-alpha) response, and white cell accumulation in rats in order to clarify the mechanisms of the beneficial effect of donor fasting and recipient EFAD. It was found that when the grafts were obtained from fasted donors and then transplanted into fed recipients, the survival rate was significantly higher for all three grafts than for those obtained from fed rats and transplanted into fed rats. The best survival was seen for pancreas grafts obtained from fasted donors and then transplanted into EFAD recipients. TNF-alpha secretion was significantly suppressed in both fasted and EFAD rats, and both the total cell count and neutrophil count were suppressed in EFAD rats. These results clearly indicate that in addition to liver grafts, both heart and pancreas grafts obtained from fasted animals are more tolerant to warm ischemic injury. Furthermore, the combination of donor fasting and recipient EFAD acts synergistically to inhibit the post-transplantation inflammatory reaction (through decreased TNF-alpha secretion and white cell accumulation), thus resulting in an improved survival.

Animals↗
PubMed1997

Protective effect of monoclonal antibodies to adhesion molecules on rat liver ischemia-reperfusion injury.

BACKGROUND: The source of reactive oxygen species in the liver remains to be elucidated. The present study was undertaken to determine whether polymorphonuclear neutrophils (PMNs) can contribute to hepatic ischemia-reperfusion injury, and pretreatment with monoclonal antibodies (mAbs) to intercellular adhesion molecule-1 (ICAM-1), lymphocyte function associated antigen-1 (LFA-1), and CD 18 could improve energy metabolism and prolong the viability of the organ. METHODS: Male Wistar rats were used. Rat liver ischemia was induced by clamping blood vessels supplying median and left lateral hepatic lobes. Monoclonal antibodies to ICAM-1, LFA-1, or CD18 were injected intravenously 5 minutes before inducing ischemia. To determine the effect of mAbs on the survival rate, total hepatic ischemia was induced by clamping the hepatic artery, portal vein, and bile duct after making a portafemoral shunt. RESULTS: Although ischemia of the liver for 90 minutes did not permit survival of the animals, pretreatment with mAbs to ICAM-1 plus LFA-1 increased the survival rate to 57%. Pretreatment with mAb to ICAM-1 failed to increase the survival rate. The number of PMNs in the liver increased continually up to 24 hours after reperfusion after 90 minutes of ischemia, and the expression of ICAM-1 was enhanced 4 hours after reperfusion. This is accompanied by a low recovery of hepatic adenosine triphosphate and, on the contrary, a marked increase in lipid-peroxide in the reperfused liver. Pretreatment with mAbs suppressed the infiltration of PMNs and the elevation of lipid peroxide and enhanced the recovery of hepatic adenosine triphosphate 6, 12, or 24 hours after reperfusion. Pretreatment with mAbs also prevented the rise in serum alanine aminotransferase level after reperfusion. CONCLUSIONS: These results suggest that PMNs contribute to ischemia-reperfusion injury in the liver 4 hours and more after reperfusion, and pretreatment with mAbs to adhesion molecules is useful for the prevention of ischemic liver cell injury.

Adenine Nucleotides↗
PubMed1997

Magnetic resonance velocity mapping of normal transtricuspid velocity profiles.

To investigate the velocity profiles of transtricuspid inflow, we examined 20 normal subjects (17 males and 3 females, mean age 27 +/- 7) by the magnetic resonance imaging (MRI). Electrocardiographic gating was performed in all anatomical and flow studies, and sequences were triggered by the R wave. Cine gradient echo images (echo time, 14 ms) were acquired in the right ventricular horizontal long axis, and from these, cine images with velocity mapping were obtained in the short axis of the right ventricle. Velocity mapping of right ventricular inflow was obtained at peak early diastolic filling. Velocity profile curves across the tricuspid inflow were obtained at each 1 cm interval from the tricuspid ring to 3 cm into the cavity. Maximum/mean velocity was 1.1 +/- 0.1 at ring level, unchanged at 1 cm from the tricuspid ring, and thereafter increased to 1.4 +/- 0.3 at cm2, and 1.5 +/- 0.3 at 3 cm as peak velocity fell. The ratio of the longest and shortest jet width cross section was 1.3 +/- 0.3 at ring level, and increased to 1.5 +/- 0.3 at 3 cm from ring level. Jet cross sectional area was 10.4 +/- 2.1 cm2 at ring level, and was unchanged at 3 cm level. Thus, tricuspid inflow velocity showed a relatively flat profile at the tricuspid ring and tip level, becoming more dispersed at 2 and 3 cm from the ring. Right ventricular inflow jet cross section was elliptic, and appeared to be relatively constant in the cross-sectional area.

Adult↗
PubMed1997

Differences in aldehyde oxidase activity in cytosolic preparations of human and monkey liver.

This study presents data showing individual differences in aldehyde oxidase activity in human and monkey liver cytosols. When assayed with benzaldehyde as a substrate, a significant inter-subject variation in the activity was found in the human liver preparations. When assayed with N1-methylnicotinamide as a substrate, the inter-subject variation of the activity was also observed, but to a lesser extent compared with that of the activity with benzaldehyde. Similarly, variations in aldehyde oxidase activity were found in the monkey liver preparations when assayed with benzaldehyde or N1-methylnicotinamide. The present study suggested that at least two isozymes of aldehyde oxidase exist in the human liver preparations.

Aged↗
PubMed1997

Atrial conduction abnormalities in patients with systemic progressive sclerosis.

BACKGROUND: Atrial abnormalities in patients with progressive systemic sclerosis have not been evaluated in terms of intra-atrial conduction. We hypothesized that a delay in atrial conduction in these patients might produce diastolic abnormalities as well as atrial arrhythmias. OBJECTIVE: To evaluate the atrial function of patients with progressive systemic sclerosis by using echocardiography to measure the intra-atrial electromechanical activation coupling interval. METHODS: Twenty patients with progressive systemic sclerosis were assessed by Doppler echocardiography. Twenty age-matched healthy controls were also evaluated. Two-dimensional guided M-modes of ventricular long axes were recorded using simultaneous phono- and electrocardiograms of the apical four chamber view at the right lateral, septal and left lateral sites of the atrioventricular rings. Transmitral and tricuspid pulsed Doppler flow velocities were also recorded. Filtered P wave duration was measured on the signal averaged ECG to determine the duration of atrial electrical activation. RESULTS: There was a delay in P on the electrocardiogram (P) at the onset of atrial contraction on long axis M-modes at all three atrioventricular ring sites in patients with progressive systemic sclerosis as compared with controls (P-right; 56 +/- 13 vs 47 +/- 10 ms, P-septal; 74 +/- 14 vs 55 +/- 10 ms, and P-lateral; 93 +/- 16 vs 72 +/- 11 ms, P < 0.01). Inter-atrial conduction time [(P-lateral)-(P-right)] was delayed in patients with progressive systemic sclerosis, compared with healthy controls (37 +/- 15 vs 25 +/- 6 ms, P < 0.01). Mitral A waves acceleration and deceleration times were also decreased in the patients. The interval was prolonged between P to the onset and the peak of the A wave in transmitral flow. Duration of the filtered P wave was significantly prolonged in progressive systemic sclerosis as compared with controls (124 +/- 12 ms vs 106 +/- 8 ms, P < 0.01). PQ intervals, E waves and acceleration and deceleration times did not differ significantly in progressive systemic sclerosis vs, controls. The A wave acceleration rate on transmitral flow (peak A wave velocity/acceleration time) showed a significant correlation with inter-atrial conduction delay (r = 0.55, P < 0.01). CONCLUSIONS: Intra-atrial electromechanical coupling intervals were delayed in patients with progressive systemic sclerosis. Thus, the mechanical late diastolic filling time due to atrial contraction in the total diastolic phase was severely limited, and this resulted in a restricted mitral A wave. We should therefore evaluate patients with progressive systemic sclerosis for significant atrial abnormalities.

Atrial Function↗
PubMed1997

Increased plasma concentrations of adrenomedullin correlate with relaxation of vascular tone in patients with septic shock.

OBJECTIVE: To investigate plasma concentrations of adrenomedullin in patients with septic shock and the potential association of these concentrations with relaxation of vascular tone. DESIGN: Prospective, case series. SETTING: Department of Emergency and Critical Care Medicine, Nara Medical University. PATIENTS: Twelve patients who fulfilled the clinical criteria for severe sepsis or septic shock (as defined by the Members of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Committee) and 13 healthy volunteers. INTERVENTIONS: Arterial blood samples were obtained via a 20-gauge cannula inserted into each patient's radial artery. MEASUREMENTS AND MAIN RESULTS: After extraction and purification, plasma adrenomedullin was measured by radioimmunoassay. Systemic vascular resistance index, pulmonary vascular resistance, cardiac index, and stroke volume index were determined with a thermodilution catheter. The mean plasma concentration of adrenomedullin was markedly higher in patients than in controls (226.1 +/- 66.4 [SEM] vs. 5.05 +/- 0.21 fmol/mL, p < .01). Moreover, these concentrations correlated significantly with cardiac index, stroke volume index, and heart rate values, and correlated significantly with decreases in diastolic blood pressure, systemic vascular resistance index, and pulmonary vascular resistance index values. CONCLUSIONS: Enhanced production of adrenomedullin in patients with septic shock may contribute to reduced vascular tone, hypotension, or both. More data are needed to clarify the role of adrenomedullin in the regulation of vascular tone in this patient population.

Adrenomedullin↗