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Biomedical subjects

Y Shimamura

Publications and source records attributed to Y Shimamura.

At least 73 records · Page 4Linked to original sources
PubMed1990

Endoscopic laser coagulation through an optical laser balloon.

An endoscope was equipped with a saline-filled latex rubber balloon at its tip to displace contaminating blood, bile, or gastric contents during operative portoscopy, biliary endoscopy, or upper gastrointestinal endoscopy. A fiber with its tip inside the balloon transmitted energy from an Nd:YAG laser for coagulation of tumors in one bile duct cancer, in six portal vein growths from primary liver cancers, and in a superficially growing stomach cancer. The balloon increased the precision of irradiation by making lesions easier to identify through displacement of bile or blood and by keeping the fiber tip at a fixed position relative to the lesion. The technique, basic experimental studies, and clinical experiences are reported.

Animals↗
PubMed1990

Nd:YAG laser irradiation to intraluminal mass lesions of the superior vena cava under laser balloon angioscopy in an experimental canine model.

A laser balloon angioscopic procedure was developed in a canine model for intraluminal mass lesions in the superior vena cava, using an endoscope bearing a very thin balloon through which Nd:YAG laser could penetrate. The balloon was made from artificially modified natural latex rubber and well expanded with saline infused through a biopsy channel. The endoscopic image of the object obtained through direct contact of the balloon expanded with saline was clear enough to observe the internal surface or branches in not only normal, but also pathological conditions of the canine SVC. The Nd:YAG laser was able to be successfully irradiated through the balloon using this procedure which, although still in its preliminary stage, may be a useful clinical, diagnostic and therapeutic tool of the future.

Angioplasty, Balloon↗
PubMed1990

Juxtacaval liver resections with the use of an internal IVC shunt tube.

Almost one tenth of more than 370 hepatectomies, mostly for tumors, involved resection of major parts of the caudate lobe, subsegment 1. Five of them were for tumors or hemangiomas here, compressing or invading the vena cava; two were for metastases of colorectal cancer located very close to the junctions of the right and middle hepatic veins with the vena cava. We would previously have deemed these tumors unresectable. In these patients the vein was banded above and below the liver, an internal shunt tube placed in preparation for shunting of blood, and the afferent liver blood flow controlled. Control of the vena cava by tightening of the bands was needed in two cases. Tumor-invaded parts of the vein wall were resected in two other cases, in whom the presence of the tube facilitated the resection but the bands did not have to be tightened. The procedure did not cause morbidity and we conclude that tumors close to the vena cava can often be resected without complex vascular exclusion techniques, even when they invade the vein.

Adult↗
PubMed1990

Intracranial hemorrhage associated with nontraumatic disseminated intravascular coagulation--report of four cases.

The authors report four cases of intracranial hemorrhage associated with nontraumatic disseminated intravascular coagulation (DIC). Two cases demonstrated a sudden onset of intracerebral hemorrhage. The other two showed chronic subdural hematoma initially, followed by acute multiple intracranial hemorrhages or general hemorrhagic diathesis. The underlying disorders were glioblastoma multiforme, thoracoabdominal aortic aneurysm, acute promyelocytic leukemia, and stomach cancer associated with disseminated carcinomatosis of the bone marrow. All patients died eventually. When the underlying disorder has a rare incidence of DIC as in glioblastoma multiforme or thoracoabdominal aortic aneurysm, the possibility of DIC and the need for immediate initiation of replacement therapy should be recognized, although the mortality is very high because the underlying disorder cannot be eliminated quickly. When the underlying disorder has a high incidence of DIC as in acute promyelocytic leukemia or disseminated carcinomatosis of the bone marrow, it is mandatory to start replacement therapy and treatment for the underlying disorder simultaneously. DIC can be controlled when the treatment for the underlying disorder is effective.

Adult↗
PubMed1990

Optic nerve degeneration caused by supraophthalmic carotid artery infusion with cisplatin and ACNU. Case report.

A 28-year-old woman with a left frontoparietal anaplastic astrocytoma was treated postoperatively with a combination of cisplatin and 1-(4-amino-2-methylpyrimidine-5-yl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU). The drugs were infused via the left supraophthalmic internal carotid artery in an attempt to avoid ocular toxicity. The patient subsequently developed blindness in the left eye and a right temporal hemianopsia from marked degeneration of the left optic nerve and tract. It is apparent that the placement of a catheter into the supraophthalmic carotid artery does not exclude visual complications.

Adult↗
PubMed1990

[Lipiodol transcatheter arterial chemoembolization for non-resectable hepatocellular carcinoma--multicenter cooperative study].

A cooperative group study was carried out on the effect of Lipiodol transcatheter arterial chemo-embolization (L-TACE) for non-resectable hepatocellular carcinoma (HCC). Thirty-seven hospitals in Japan participated in this study and a total of 157 eligible patients included 138 males and 19 females with an average age of 60.3 y.o. In the chemo-embolization, Lipiodol mixed with 20-50 mg/m2 of doxorubicin (adriamycin) was given through a catheter, and this was followed by embolization with gelatin sponge. Effect of additional oral 5-FU (150-200 mg/day) was also studied as an open trial. Levels of serum alpha-feto protein decreased at 10 days after L-TACE, and this decrease lasted for 5 weeks. CR was observed in one patient, PR in 33, MR in 24, NC in 66 and PD in 16. The response rate was 24.3%. Cumulative one-year, two-year and three-year survival rates were 56.0%, 30.8% and 26.4%, respectively. It was concluded that higher survival rates after L-TACE were observed when (1) patients had better functional reserves of the liver, (2) HCC was in the less advanced stage and (3) L-TACE was carried out more than twice. A reduction of the tumor size after L-TACE did not necessarily mean a good prognosis for the patients. There was no significant difference in the survival rate between the patients taking or not taking 5-FU.

Adult↗
PubMed1989

Radiological studies of the cheiro-oral syndrome.

Four cases of the cheiro-oral syndrome are reported, with a review of the clinical symptoms and signs and the neuroradiological methods used to demonstrate the responsible lesion. In each case, angiography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed. The lesion was found in the thalamus in three cases and in the pons in one. Infarction had occurred in three cases and haemorrhage in one. Angiography revealed normal findings in all cases. CT at the onset of the symptoms demonstrated a small haemorrhage in the thalamus in one case but was not helpful in the others, and MRI was required to identify infarction. The anatomical sites responsible for the cheiro-oral syndrome have been reported to be in the central gyrus, in the thalamus, and in the brain stem. The clinical symptoms and signs reported in the literature and in our four cases are reviewed to evaluate aetiological factors and clinical features according to the three different sites of lesions causing this syndrome.

Adult↗
PubMed1989

Effects of transcatheter arterial chemoembolization with oral chemotherapy on hepatic neoplasms.

An investigation was carried out into the effects of lipiodol-transcatheter arterial chemoembolization (L-TACE) therapy on hepatocellular carcinoma (HCC) and metastatic liver cancer, as well as the effects of oral 5-fluorouracil administration after L-TACE. For L-TACE, lipiodol mixed with adriamycin (doxorubicin) was injected through a catheter inserted into the tumor feeding artery and this was followed by embolization with a gelatin sponge. Twenty national hospitals throughout Japan participated in this multicenter co-operative open trial. A total of 102 patients became the subjects of study, including 75 HCC patients, 12 metastatic liver cancer patients treated with L-TACE, and 15 HCC patients who had hepatectomy after L-TACE. In 22% of the HCC patients and in 42% of the metastatic liver cancer patients, the tumor size was reduced by more than 50% after L-TACE. 73% of the 63 HCC patients showed a more than 50% reduction of the levels of serum alpha-fetoprotein. Although the survival rates of the HCC patients who had a hepatic resection were better than those who had not, there was no statistically significant difference between the survival rates of the HCC patients and those of the metastatic liver cancer patients treated with L-TACE. The survival rates of the HCC patients after L-TACE did not change as a result of oral 5-fluorouracil administration. It was therefore concluded that L-TACE is an effective way of treating both HCC patients and metastatic liver cancer patients, and that repeated L-TACE should be considered for some patients whose serum levels of alpha-fetoprotein rose again after L-TACE. Further follow-up studies will be needed to discover the effects of oral chemotherapy after L-TACE.

Administration, Oral↗
PubMed1989

Multimodal treatment of hepatocellular carcinoma.

Our multimodal treatment of hepatocellular carcinoma (HCC) has brought about a significant improvement of the survival rate. It consists of a combination of hepatectomy and transcatheter arterial embolization using lipiodol (L-TAE). In order to facilitate L-TAE, we have developed a special catheter with notches. A group of patients with HCC (124 cases), excluding cases with absolutely non-curative resections and operative deaths, were treated between December 1980 and November 1986. Each case was treated for more than 1 year after hepatectomy. The patients were divided into two groups: A, patients with a single tumor not larger than 5 cm, and B, cases with larger tumors or more than one lesion. Some patients in each group were treated with L-TAE after hepatectomy. In group A, there was no significant difference in survival between treated and non-treated cases. In group B, L-TAE gave a significantly better survival than no postoperative treatment.

Carcinoma, Hepatocellular↗
PubMed1989

Coagulation and fibrinolysis in chronic subdural hematoma.

In 19 patients with chronic subdural hematoma, coagulation and fibrinolysis in venous blood taken at the time of surgery and in the hematoma contents aspirated from chronic subdural hematoma were studied. Compared with coagulation results for venous blood, the hematoma contents demonstrated marked prolongation of the recalcification time, prothrombin time, and activated partial thromboplastin time, and marked reduction of clotting factor V, the hepaplastin test, prothrombin, and fibrinogen. Antithrombin III was also decreased, and fibrinopeptide A was increased in the hematomas. Fibrinolytic results demonstrated that both plasminogen and alpha 2-plasmin inhibitor were decreased, and both fibrinopeptide B beta 15-42 and fibrin and fibrinogen degradation products were increased in the hematomas. These findings indicate excessive activation of the clotting system, thrombin generation, and increased fibrinolytic activity occurring in the hematomas. From these results, excessive activation of both the clotting and fibrinolytic systems is emphasized to be the possible etiological factor for the origin and development of chronic subdural hematoma.

Adult↗
PubMed1989

Poor prognoses following left hepatic trisegmentectomies for cancer.

Five patients with hepatocellular carcinoma, and one with a gallbladder cancer with liver metastases, underwent left hepatic trisegmentectomy with, in four cases, resection of the left caudate lobe. A bleeding peptic ulcer and an anaphylactic shock due to a drug allergy caused two hospital deaths. A third major complication was a prolonged bile leakage which healed spontaneously. One patient who died in hospital had not undergone a radical resection, and all four patients surviving the procedure eventually died with recurrent local (and sometimes also distant) tumors between 3.5 and 11 months after resection. The results appear to give relatively few indications for left trisegmentectomy in the treatment of these tumors.

Adult↗
PubMed1989

[Arterial-portal shunting in hepatic cavernous hemangioma; a case report].

A 60-year-old woman had a small hepatic tumor in the right lobe detected by CT scan. Angiography showed a hypervascular lesion with shunting of dense contrast material into portal vein radicles. Resected specimen revealed a cavernous hemangioma. The angiographic differentiation between small hemangiomas and malignant hypervascular neoplasms of the liver can be difficult.

Arteriovenous Fistula↗
PubMed1988

Combined peripheral and central chemoembolization of liver tumors. Experience with lipiodol-doxorubicin and gelatin sponge (L-TAE).

Patients with primary and a few with secondary liver tumors were embolized through the hepatic artery. Lipiodol and doxorubicin occluded peripherally, which was immediately followed by central embolization with gelatin sponge cubes. Preoperative embolizations were made for diagnostic and possible surgical adjuvant purposes. Extensive postembolization necrosis was common in tumors less than 5 cm in diameter, and tumor markers usually decreased temporarily after treatment. There were moderate side effects of pain, fever and nausea, and an acceptable complication and mortality rate with no deaths after embolization alone. This warrants further research on the method, which also seemed to improve the detection rate for small hepatocellular carcinomas.

Carcinoma, Hepatocellular↗
PubMed1988

Roles of the respiratory Na+ pump in bioenergetics of Vibrio alginolyticus.

Bioenergetic characteristics of Na+ pump-defective mutants of a marine bacterium Vibrio alginolyticus were compared with those of the wild type and revertant. Generation of membrane potential and motility at pH 8.5 in the mutants were completely inhibited by a proton conductor, carbonylcyanide m-chlorophenylhydrazone, whereas those in the wild type or revertant were resistant to the inhibitor. Motility and amino acid transport were driven by the electrochemical potential of Na+ not only in the wild type or revertant but also in the mutants. In the absence of the proton conductor, motility and amino acid transport of the mutants did not significantly differ from those of the wild type or revertant even at pH 8.5, where the Na+ pump has maximum activity. Therefore, the electrochemical potential of Na+ in the mutants seemed to be maintained at a normal level by a respiration-dependent H+ pump and Na+/H+ antiporter. On the other hand, growth of the mutants became defective as the medium pH increased, especially on minimal medium. These results indicate that the Na+ pump is an important energy-generating mechanism when nutrients are limited at alkaline pH.

Aminoisobutyric Acids↗
PubMed1988

[Cytofluorometric and histopathological studies on non-cancerous liver lesions after lipiodol-transcatheter arterial embolization].

We have investigated the effects of preoperative Lipiodol-Transcatheter arterial embolization (Lp-TAE) on both the nuclear DNA content of noncancerous liver cells by DNA-cytofluorometry (using NIKON SPM-RF1-D), and the histopathological findings of liver lesions. Lp-TAE through the hepatic artery was performed on ten primary hepatocellular carcinoma patients using Gelfoam in combination with adriamycin (40 mg) or mitomycin C (20 mg), emulsified in Lipiodol (10 ml) and 60% Urografin (2 ml). And hepatic resection was carried out after one or two months later in each case. Histologically, primary hepatocellular carcinoma lesions showed various patterns of necrosis, while the non-cancerous liver cells did not show hepatocellular infarction in the liver cirrhosis. The results of the nuclear DNA content showed an increase in the fractions of poliploid cells in the non-cancerous lesions treated with Lp-TAE compared with that in the normal age-matched controls. But we found no remarkable differences in the ploidy patterns between Lp-TAE treated patients and untreated patients with liver cirrhosis. In conclusion, preoperative Lp-TAE does not induce any remarkable histological hepatocellular damage of non-cancerous lesion and does not affect nuclear DNA content of non-cancerous liver cells.

Adult↗