Search PubMed⌕ Search

Biomedical subjects

K Komori

Publications and source records attributed to K Komori.

At least 127 records · Page 7Linked to original sources
PubMed1994

Metoclopramide inhibits development of esophageal varices in rat model.

We examined the preventive effect of metoclopramide on the development of esophageal varices in a rat model. Thirty rats were divided into three groups: metoclopramide (7.5 mg/kg twice a day, intraperitoneally), control group I (saline 2 ml/kg twice a day, intraperitoneally), and control group II (incised lower esophageal sphincter and metoclopramide 7.5 mg/kg twice a day, intraperitoneally). On the 14th postoperative day, lower esophageal sphincter pressure in the metoclopramide group (8.6 +/- 1.4 cm H2O) increased more than in the control groups (5.4 +/- 0.5, 5.0 +/- 0.5 cm H2O, P < 0.01). Development of small collateral vessels from the spleen to the retroperitoneum was evident only in the metoclopramide group, as seen on the portography (P < 0.01). Histologically, the variceal area of the horizontal cross section of the esophagus in the metoclopramide group (0.62 +/- 0.26 mm2) was significantly smaller than in the controls (2.67 +/- 0.95, 2.78 +/- 0.82 mm2), determined using an image processor-analyzer for photographing histological specimens (P < 0.01). We also investigated the effect of metoclopramide on smooth muscle cells in the rat portal vein, using isometric-tension recording. Metoclopramide relaxed the smooth muscle precontracted with norepinephrine, in a concentration-dependent manner. Thus, metoclopramide inhibits the development of esophageal varices in this rat model due to both an increase in resistance of the lower esophagus and to development of small collaterals.

Animals↗
PubMed1994

Intimal hyperplasia of experimental autologous vein graft in hyperlipidemic rabbits with poor distal runoff.

Poor distal runoff and hyperlipidemia are factors affecting the fate of an implanted graft. In the present study, combined effects of poor distal runoff and hyperlipidemia on intimal hyperplasia (IH) of the vein graft were examined in a newly developed poor distal runoff model in rabbits. A poor distal runoff model was prepared in the right hindlimb of 30 rabbits. These animals were divided into two groups, depending on the diet provided; normolipidemic diet group (Group NL, n = 14) and hyperlipidemic 1% cholesterol diet group (Group HL, n = 16). Four weeks after preparing the poor runoff model, the femoral vein was implanted into the ipsilateral femoral artery. At 2, 4 and 6 weeks, the grafts were harvested. IH of the graft was measured and macrophages in the IH were examined immunohistochemically. Intimal cell proliferation was also determined by bromodeoxyuridine (BrdU) incorporation. IH of the vein graft was significantly accelerated in cases of poor distal runoff and hyperlipidemia. There were no macrophages in the IH in the NL group. In the HL group, macrophages infiltrated the outer layer of IH, sometimes just above the internal elastic lamina, and increased with time. In the poor distal runoff limbs at 6 weeks, macrophages also appeared in the subendothelial layer but were absent in that layer in the controls. Intimal cell proliferation expressed as the BrdU labeling index (LI) was maximum at 2 weeks. In the HL group, BrdU LI of IH in the poor distal runoff limb was higher than in the control at 2 and 4 weeks. Throughout the experiments, BrdU LIs in the HL group were significantly higher than in the NL. Hyperlipidemia accelerates intimal cell proliferation to a greater extent, then does IH. In cases of a poor distal runoff, the enhancement of cell proliferation by hyperlipidemia is augmented. These responses, in the presence of a hyperlipidemia, may be closely related to the migration of macrophages.

Animals↗
PubMed1994

Detection of active cytomegalovirus infection in inflammatory aortic aneurysms with RNA polymerase chain reaction.

PURPOSE: We previously reported the possible role of human cytomegalovirus in the pathogenesis of inflammatory aortic diseases. To further analyze the viral cause of human aortic diseases, in this study we examined the presence and the replication of human Herpesviridae in 60 aortic tissues, including 7 inflammatory aneurysms, 37 atherosclerotic aneurysms, and 16 normal aortas. METHODS: To detect the genome of herpes simplex virus (type 1, type 2), cytomegalovirus, and Epstein-Barr virus, DNA polymerase chain reaction for each virus was performed. To analyze these herpesviral replications, the viral transcript was detected with RNA polymerase chain reaction. RESULTS: The DNA polymerase chain reaction showed that either herpes simplex virus or cytomegalovirus was present more frequently in inflammatory (29% or 86%, respectively) and atherosclerotic aneurysms (27% or 65%, respectively) than in normal aortic tissues (6% or 31%, respectively), whereas the Epstein-Barr viral genome was not detected in any aortic tissue specimens. By the use of RNA polymerase chain reaction, only the cytomegaloviral transcript was recognized in 71% of the inflammatory aneurysms but was not recognized in any other tissue specimens. No other herpesviral transcripts were detected in any tissue specimens examined in this study. CONCLUSIONS: Our results thus suggest that the human herpesviruses may play various roles in the pathogenicity of aortic diseases, in particular the replicating infections of the cytomegalovirus might potentially cause the formation of inflammatory aneurysms.

Aortic Aneurysm↗
PubMed1994

Surgical strategy of concomitant abdominal aortic aneurysm and gastric cancer.

PURPOSE: Selecting the most appropriate surgical approach for patients with abdominal aortic aneurysm (AAA) and concurrent gastric cancer remains controversial. In an attempt to develop guidelines for the management of two concurrent lesions, a retrospective review of patients with concomitant AAA and gastric cancer was undertaken. METHODS: During the period from January 1985 to December 1992, a total of 222 patients with AAA were admitted to our hospital. Among these, seven patients (3.2%) had gastric cancer and concurrent AAA. Six of the seven patients were treated surgically for both lesions with either a one- or two-stage operation. One patient underwent only an exploratory laparotomy because of the peritoneal dissemination of the gastric cancer. Four of the six patients underwent a two-stage operation. In three cases, the resection of the malignancy was performed first because the gastric cancer was diagnosed as advanced before operation. In one case, the aneurysmectomy was performed first because the aneurysm was more than 6 cm in diameter and the gastric cancer was in an early stage of development. Two of the six patients underwent a one-stage operation and a simultaneous resection was carried out by way of segregated approaches, such as the retroperitoneal approach for AAA and the transperitoneal approach for the malignant lesion. RESULTS: Five of the seven patients (71.4%) are still alive. The length of follow-up for these patients ranged from 4 months to 4 years. CONCLUSIONS: The principles of our surgical approaches for concomitant AAA and gastric cancer are as follows. (1) The lesion that absolutely indicates urgent operation should be operated on first. (2) If the malignant lesion is advanced, it is resected first. (3) If the malignancy is not advanced, the AAA should be resected first by the retroperitoneal approach. (4) Simultaneous resection by way of segregated approaches is useful in some patients with early gastric cancer. (5) Both lesions must be resected eventually for improvement of the long-term survival chances.

Aged↗
PubMed1994

Impaired vasodilation of peripheral arteries in response to acetylcholine in human beings with abdominal aortic aneurysm.

PURPOSE: Most aneurysms are generally presumed to be atherosclerotic in origin. Endothelium-dependent dilations were impaired in the cases of atherosclerosis. It is not clear whether the endothelial function of the peripheral arteries in humans with abdominal aortic aneurysm is impaired. The purpose of this study is to characterize endothelium-dependent relaxations in patients with abdominal aortic aneurysm. METHODS: Responses of external iliac artery blood flow to acetylcholine (30 micrograms/min: an endothelium-dependent vasodilator) and sodium nitroprusside (10 micrograms/min: a direct dilator of smooth muscle) were examined by electromagnetic blood flow meter in a group of 13 patients consisting of six patients with abdominal aortic aneurysm, six patients with colorectal cancer, and one patient with abdominal aortic aneurysm and rectal cancer. RESULTS: The mean blood flow before administration of drugs was comparable between the two groups. In the patients with abdominal aortic aneurysm, infusion of acetylcholine did not significantly increase the mean blood flow, whereas in the patients with colorectal cancer, acetylcholine increased the blood flow significantly. The increases of blood flow by an infusion of sodium nitroprusside were comparable between the two groups. In one patient with abdominal aortic aneurysm and rectal cancer, acetylcholine did not alter the blood flow, and sodium nitroprusside increased the blood flow, which was similar to what the patient with abdominal aortic aneurysm experienced. CONCLUSIONS: These results suggest that in patients with abdominal aortic aneurysm, the endothelium-dependent vasodilations of the peripheral artery were impaired without changing the smooth muscle property.

Acetylcholine↗
PubMed1994

Do patients with intermittent claudication need surgical treatment?

To determine whether surgical intervention is of therapeutic significance for patients with intermittent claudication (IC), 315 patients with IC followed in our outpatient clinics for the past 8 years 3 months (mean of 3 years 10 months), including 142 non-operated and 173 operated patients, were investigated as to changes in symptoms and the prognosis. Changes in symptoms in both groups were analyzed according to the variable distances of claudication and location of the diseased artery. To examine the degree of association between surgery and improvement of symptoms, Goodman and Kruskal's gamma was used. For all subgroups with a variable claudication distance (group A; distance < 100 m, B: 100-500 m, C: > 500 m), surgery inversely correlated with improvement in symptoms (group A; gamma = -0.378, group B; gamma = -0.651, group C; gamma = -0.828). According to location of the diseased artery, surgery correlated with improvement in symptoms in aorto-iliac (gamma = -0.811), aorto-ilio-superficial femoral (gamma = -0.641), and superficial femoral-distal (gamma = -0.533) groups but not in superficial femoral (gamma = -0.427) or infrapopliteal (gamma = -0.194) alone groups. Concerning the prognosis, no significant difference was noted between operated and non-operated groups (p = 0.35). These computed data show that surgical intervention has therapeutic significance for patients with IC, except for cases of claudication with segmental occlusion of the superficial femoral or infrapopliteal artery alone.

Aged↗
PubMed1994

Persistent sciatic artery: two case reports and a review of the literature.

Persistent sciatic artery (PSA) sometimes shows variant vascular symptoms such as chronic or acute limb ischaemia and a pulsatile mass in the buttocks caused by aneurysmal dilatation. This report presents two cases of surgically treated PSA that caused lower-limb ischaemia. The first patient, a 58-year-old man, showed acute limb ischaemia in the chronic clinical course, and thrombectomy and patch angioplasty were performed. The second patient, a 70-year-old woman, had an incomplete type of PSA without development of the femoral artery while complaining of a 10-year history of coldness and numbness in the left lower limb. A left common iliac to profunda femoris arterial bypass was performed. This is the second case of symptomatic incomplete PSA reported in the literature. This report also reviews 45 cases of PSA published since 1977. The diagnosis of PSA requires arteriography that includes the bilateral iliac systems. Femoropopliteal bypass and, in the case of sciatic artery aneurysm, a ligature of the sciatic artery are recommended for the surgical treatment of PSA.

Aged↗
PubMed1994

[Evidence for the existence of L-dopa-immunoreactive neurons in the human mesencephalic region].

The existence of L-3,4-dihydroxyphenylalanine (L-DOPA) immunoreactivity is demonstrated for the first time in some neurons in the human mesencephalic region, using an immunohistochemical method with a newly raised, highly specific anti-L-DOPA antiserum. In this study, we have found many L-DOPA-positive/dopamine (DA)-positive neurons. On the other hand, we observed a few L-DOPA-positive/DA-negative cell bodies in the dopaminergic regions in the midbrain. The present results suggest the possibility of the existence of more than one neuronal group in the human mesencephalic ventral tegmental area region. L-DOPA in one group is an intermediate metabolite for decarboxylation to DA and in another group may exist as an end-product. L-DOPA in the latter group could be a neuromodulator and/or neurotransmitter. Thus, we suggest that L-DOPA plays an important role besides being an intermediate of DA in the human mesencephalon.

Antibody Specificity↗
PubMed1994

[A case of atypical presenile dementia].

Kosaka (1993) reviewed 16 cases of slowly progressive presenile cortical dementia thought to be a clinicopathological entity with pathological features characterized by circumscribed lobar atrophy, diffuse neurofibrillary tangles, and calcification of the Fahr type, however, the clilical features of this new entity are not known in the description of detail. We report a patient with atypical presenile dementia which appeared to be consistant with that entity, together with the results of a comprehensive neuropsychological and neuroradiological examination. The patient was a 65-year-old right-handed housewife. At about 58 years of age, she started to lose spontaneity and develop a mild memory disturbance. At age 61 she transiently, experienced hallucinations and delusions. During the subsequent 8 years there was a very slight decline in global intellectual efficiency. In addition, she showed slow but definite progression of language disturbances characterized by anomia and loss of ability to grasp the meaning of words, particularly abstract nouns. She performed poorly on tasks with good sensitivity for detecting frontal lobe dysfunction, such as the Wisconsin Card Sorting Test and the hand sequence test. All other cognitive functions appeared to be relatively well preserved, however moderate dyscalculia was present. There was no socially inappropriate or stereotyped behavior, but the patient lost insight into her disease. The patient's activities of daily living on the ward were self-maintained. An EEG was normal. CT and MRI scans showed circumscribed bilateral fronto-temporal atrophy and bilateral mineralization in the basal ganglia and cerebellar white matter.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Identification of L-dopa immunoreactivity in some neurons in the human mesencephalic region: a novel dopa neuron group?

The presence of L-3,4-dihydroxyphenylalanine (L-DOPA) immunoreactivity is reported for the first time in some neurons in the human mesencephalic region, using an immunohistochemical method with a newly raised, highly specific anti-L-DOPA antiserum. We have found many L-DOPA-positive/dopamine (DA)-positive and a few L-DOPA-positive/DA-negative cell bodies in dopaminergic regions in the midbrain. The present results suggest the existence of more than one neuronal group of L-DOPA in the human mesencephalon. L-DOPA in one group is an intermediate metabolite for decarboxylation to DA and in another group may exist as an end-product. L-DOPA in the latter neurons could be a neuromodulator and/or neurotransmitter. Thus, we suggest that L-DOPA plays an important role besides being an intermediate of DA in the human mesencephalon.

Dopamine↗
PubMed1993

The reversibility of impaired prostacyclin production of the vein graft.

The effects of changes in shear stress (shear stress variation) on production of prostacyclin (PGI2) were examined in canine autologous vein grafts, which were implanted in the poor or normal distal runoff limbs. Four weeks after grafting, the vein grafts were perfused ex vivo and PGI2 was assayed as 6-ketoprostaglandin F1 alpha. The vein grafts were perfused under constant flow for the first 30 min and then under pulsatile flow simulating an abnormal flow with a low shear stress variation or a normal flow with a high shear stress variation for the next 30 min. Basal production rates (30-min cumulative PGI2 production) of vein grafts implanted in the poor runoff and normal runoff limbs were 1.97 +/- 0.71 and 2.19 +/- 0.40 ng/cm2, respectively, with no significant difference. Pulsatile flow effects (increased PGI2 production between 30 and 60 min) of simulated abnormal versus normal flow were 0.50 +/- 0.50 ng/cm2 versus 2.31 +/- 1.87 ng/cm2 in vein grafts implanted in poor runoff limbs (P < 0.05) and 0.48 +/- 0.41 ng/cm2 versus 3.48 +/- 1.08 ng/cm2 in vein grafts implanted in normal runoff limbs (P < 0.01), respectively. There were no significant differences in simulated normal flow effects between poor runoff limbs and normal runoff limbs. The results indicate that the release of PGI2 in vein grafts may decrease in the presence of an abnormal blood flow with a low shear stress variation. In addition, it is suggested that even vein grafts implanted in the poor runoff could increase PGI2 production once the grafts were placed into normal arterial circulation.

Animals↗
PubMed1993

Operative transluminal laser angioplasty as the sole treatment for late stenoses of femorodistal artery bypass graft: experimental and clinical studies.

To determine the role of Nd:YAG laser thermal angioplasty as the sole treatment for late stenoses of femorodistal artery bypass graft, the lasing effect of a larger size of hot-tip probe (3, 4, and 5 mm) was experimentally studied in vitro. For an adequate lasing effect, 30 watts of laser power output for 3 seconds was needed for the 3 mm probe, 40 watts for the 4 mm probe, and 50 watts for the 5 mm probe, respectively. Based on these results, we used Nd:YAG laser thermal angioplasty alone for 25 grafts, including 16 polytetrafluoroethylene (PTFE) grafts, eight saphenous vein grafts, and one externally supported (EXS) Dacron graft in which the stenotic lesions were detected by deterioration of the Doppler flow waveform pattern or a significant fall in the ankle/brachial pressure index (ABPI). Follow-up was from 3 to 24 months (average of 9 months) for PTFE grafts, from 5 to 21 months (average of 11 months) for saphenous vein grafts, and 13 months for the EXS Dacron graft following femorodistal artery reconstructions. Stenotic lesions were most common in the distal anastomotic sites: 11 PTFE grafts, three saphenous vein grafts, and one EXS Dacron graft. Among these, 13 grafts showed a type II flow waveform pattern at the time of surgery. Clinical success was achieved in 12 of the PTFE grafts (75%), in five of the vein grafts (62.5%), and in the single EXS Dacron graft. Four PTFE and three saphenous vein grafts failed subsequent to repeat intraoperative balloon angioplasty in three and graft extension in three and one graft interposition.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Management of concomitant abdominal aortic aneurysm and gastrointestinal malignancy.

Selecting the most appropriate surgical approach for patients with abdominal aortic aneurysm (AAA) and gastrointestinal malignancy remains controversial. In an attempt to develop guidelines for the management of patients with these two simultaneous lesions, a retrospective review of patients who had concomitant AAA and gastrointestinal malignancy was undertaken. During the period from January 1985 to February 1993, 229 patients with AAA were admitted to our hospital. Among these, 19 patients (8%) had a gastrointestinal malignancy together with AAA and were divided into 2 groups. Group I was composed of 11 patients who underwent either a 1- or a 2-stage operation for both lesions. Group II was composed of eight patients who either underwent an operation for one lesion (six patients) or did not have any operation (two patients). Among group I, six patients underwent the two-stage operation. In four of the six patients, the malignancy was resected first. In the remaining two patients, the aneurysmectomy was performed first, because, in one patient, the aneurysm was more than 6 cm in diameter, and, in the other patient, the aneurysm was a saccular type. Among group I, five patients (two patients with gastric cancer, and one patient each with esophageal cancer, rectal cancer, and malignant lymphoma of the stomach) underwent a one-stage operation. In three of the five patients (two patients with gastric cancer and one patient with esophageal cancer), simultaneous resection was carried out by using segregated approaches, namely, the retroperitoneal approach for AAA and the transperitoneal approach for malignancy. Although the clinical characteristics of the patients were different, 8 of the 11 patients (73%) in group I are still alive, whereas only 1 of the 8 patients (13%) in group II is still alive. The principles of our surgical approaches for concomitant AAA and gastrointestinal malignancy are as follows: (1) The lesion that absolutely indicated urgent surgery was resected first. (2) If both lesions were asymptomatic, the malignancy was resected first. (3) Simultaneous resection using different approaches was useful in some patients with concomitant upper early gastrointestinal malignancy. (4) Both lesions need to be resected eventually for better long-term survival.

Aortic Aneurysm, Abdominal↗
PubMed1993

Correlation of long-term results of extra-anatomic bypass and flow waveform analysis.

To investigate the correlation between the long-term results of an extra-anatomic bypass and operative flow waveform analysis, we retrospectively reviewed 32 axillofemoral and 21 femorofemoral bypasses for between 1 and 5 years after surgical repair. For the grafts with a type O or I flow waveform pattern, the patency at 3 years (83%) and at 5 years (83%) was superior to grafts with a type II flow waveform (69 and 60%). For the axillofemoral bypass grafts with a type O or I waveform, the patency rate was 92% at 5 years. In contrast with the type II flow, the patency rate was 70% at 5 years. For the femorofemoral bypass with a type O or I and a II flow waveform, the patency at 4 years was 67 and 46%, respectively. In cases with concomitant superficial femoral artery occlusion, the flow waveform was type O or I in 23% and type II in 77%. The patency rate at 5 years was 85% for cases with a patent superficial femoral artery, and 51% for an occluded superficial femoral artery (p < 0.05). These results suggest that the long-term outcome of extra-anatomic bypass correlates with the operative flow wave analysis. In addition, good long-term results and an accurate flow wave pattern depend on the distal run-off, particularly the presence of a patent superficial femoral artery.

Adult↗
PubMed1993

Natural course of endothelium-dependent and -independent responses in autogenous femoral veins grafted into the arterial circulation of the dog.

We examined the natural course of endothelium-dependent and -independent responses in reversed autogenous vein grafts during regeneration and tissue repair processes after vein grafting in dogs. Vein grafts implanted in the canine femoral artery were removed, cut into rings, and suspended in organ chambers for isometric tension recording at 3 days and 1, 2, 4, and 6 weeks after implantation. Endothelial cells were denuded from some rings. Control veins were taken from nonsurgically treated femoral veins. Acetylcholine caused endothelium-dependent relaxations in the control veins, whereas in the vein grafts there was no evidence of endothelium-dependent relaxations to acetylcholine 3 days after the operation. Acetylcholine caused endothelium-independent contractions throughout the study. The endothelium-dependent responses to ADP and calcium ionophore A23187 were constantly maintained. Three days after the operation, the amplitude of norepinephrine-induced contractions of the vein grafts was impaired, and at 1 week the amplitude was recovered, although it was significantly smaller than the amplitude of contractions of the control veins at any postoperative period. Endothelium-independent relaxations to sodium nitroprusside were maintained throughout the study. Thus, there was a selective loss of acetylcholine-mediated relaxation in vein grafts in the early postoperative stage, a time when the intima is not thickened. These altered responses in vein grafts in the early postoperative period may have a role in graft failure.

Animals↗
PubMed1993

Elevation of tumor-associated carbohydrate antigens in patients with diffuse panbronchiolitis.

We investigated the serum levels of the tumor-associated carbohydrate antigens sialyl SSEA-1 (SLX) and sialyl Lewis(a) (CA19-9) in patients with diffuse panbronchiolitis (DPB) and other nonmalignant lung diseases. Both antigens were high in the serum and bronchoalveolar lavage fluid (BALF) of patients with DPB, bronchiectasis (BE), idiopathic pulmonary fibrosis (IPF), and interstitial pneumonia associated with collagen vascular disease (CVD). Markedly high levels of the antigens were demonstrated in the serum and BALF from patients with DPB. An immunohistochemical study of open-lung biopsy specimens from patients with DPB indicated that these antigens were selectively expressed on the bronchiolar epithelial cells and mucinous exudates in airspaces. Low-dose, long-term erythromycin (EM) treatment was recently reported to be effective for DPB, and we investigated its influence on serum and BALF antigen levels in DPB patients. Antigen levels in both serum and BALF decreased after EM treatment, with improvement of symptoms and laboratory data, and there was a significant correlation between the reduction in the SLX level in serum and neutrophil percentage in BALF pre- and post-EM treatment. Our result suggests that secreted carbohydrate antigens from the bronchiolar epithelium in DPB may appear in the serum as a result of airway damage in the lower respiratory tract, and serum levels of the antigens may be decreased by a reduction in neutrophils in BALF after EM treatment.

Adult↗
PubMed1993

Two cases of lung carcinoma with osteoplastic bone metastasis.

Two cases of lung carcinoma with osteoplastic bone metastasis are reported. The bone roentgenogram of a 66-year-old woman with pleuritis carcinomatosa revealed multiple sclerotic changes in the right forearm, lumbar spine, and pelvis. Biopsy at internal fixation of the left humerus revealed metastatic adenocarcinoma with osteoplastic change. In a 77-year-old man with small cell carcinoma of the lung, after chemotherapy, osteoplastic bone changes were detected in roentgenograms. An ivory vertebra formation was seen in L1, L2 and L4, and bone scintigram showed, additionally, uptake in the ilium.

Adenocarcinoma↗