Biomedical subjects

T Sakurada

Publications and source records attributed to T Sakurada.

At least 91 records · Page 5Linked to original sources

PubMed1997

A localized fibrous tumor (mesothelioma) in the mediastinum: report of a case.

We report herein the rare case of a 51-year-old Japanese woman who underwent thoracotomy for a mass in the mediastinum which was found to be a benign localized fibrous tumor, otherwise known as a mesothelioma. The clinical behavior of this tumor is thought to be unpredictable, and therefore we emphasize that long-term follow-up of patients with localized fibrous tumors is necessary, even if the histological features are benign.

Female↗

PubMed1997

[Pharmacological profile of sendide, a tachykinin NK-1 receptor antagonist].

Progress in the characterization of tachykinin receptors and the understanding of the physiological and pathological roles of tachykinins is highly dependent on the discovery of potent and selective antagonists with metabolic stability. We have recently described a peptidic antagonist of the tachykinin NK-1 receptor, sendide (Tyr-D-Phe-Phe-D-His-Leu-Met-NH2), that is a selective and extremely potent antagonist of NK-1 receptors, but displays no antagonistic activity on the response induced by NK-2- or NK-3-receptor agonists in the mouse spinal cord. When co-administered with substance P (SP) intrathecally (i.t.), sendide markedly inhibited the scratching, biting and licking behavior induced by SP in a dose-dependent manner. The antagonistic effect of sendide on the SP-induced behavioral response was approximately 7300 times more potent than that of CP-96,345, a non-peptidic NK-1-receptor antagonist. The duration of the antagonistic effect of sendide was longer than that of CP-96,345. The behavioral response elicited by other NK-1-receptor agonists, septide, physalaemin and [Sar9, Met (O2)11]-SP, was reduced significantly by a small dose of sendide. In the [3H]-SP binding assay using mouse spinal cord membranes, sendide potently displaced [3H]-SP binding, with a potency approximately 5.4 x 10(4) times greater than that of CP-96,345. Moreover, i.t. administration of sendide was found to produce the antinociceptive effect through the blockage of NK-1 receptors in the mouse formalin and capsaicin tests. Sendide is therefore likely to become a powerful pharmacological tool for studying the functional roles of NK-1 receptors in the central nervous system.

Analgesics↗

PubMed1997

[A case of tricuspid valve endocarditis in a non-addicted adult person without underlying cardiac disease].

A very rare case of tricuspid valve endocarditis which developed in a healthy adult was observed. An 18-year-old man with no history of heart disease nor use of stimulant drugs was diagnosed as having cardiac tumor, introduced to this hospital and admitted. Before the operation, symptoms characteristic to infective endocarditis such as high fever and embolism were not observed, but the tumor was detected in the right ventricle by echocardiography. The patient underwent cardiotomy. The thrombus was removed and annuloplasty was performed by Kay's method, and good results were obtained. Pathologically the disease was diagnosed as infective endocarditis accompanied by thrombus. The postoperative course has been good. When the injury of the valve is slight, the surgical method preserving patient's own valve such as excision of localized vegetation and annuloplasty appears to be useful.

Adolescent↗

PubMed1997

[A case of localized pleural mesothelioma].

Localized pleural mesothelioma is reported. A 62-year-old male had been observed as a patient with old tuberculosis of the left lung for a few decades. For detailed examination of fever of unknown cause and abnormal shadow on the chest X-ray, the patient was introduced to our hospital. By percutaneous cytodiagnosis, the illness was diagnosed as pleural mesothelioma, and the patient underwent surgery. Since adhesion of the tumor to the lower lobe of the lung was extremely tight, the tumor and the left lower lobe were resected as a mass. The tumor was about 15 cm in diameter, weighed 1,300 g and a slight pleural effusion was observed. The tumor was diagnosed as malignant localized pleural mesothelioma pathologically. Localized pleural mesothelioma should be subjected to surgery in the early stage, in principle. Even in cases difficult to diagnose, operation should not be delayed by repeating easy-going needle-biopsy or a long-term treatment with antitubercular drugs. The postoperative course of this case has been good, and no recurrence nor metastasis has been detected.

Humans↗

PubMed1997

[Abdominal aortic surgery in Stanford type B chronic dissecting aortic aneurysm].

Three cases of a chronic type B dissecting aneurysm which required abdominal aortic reconstruction are presented. Constriction of the iliac artery due to dissection was found in case 1, in case 2 the left subclavian artery originated from a giant false lumen, and arteriosclerosis obliterans was observed in case 3. The left renal artery originated from a false lumen in all cases. Each patient underwent preliminary graft replacement of the abdominal aorta because using the femoral artery for extracorporeal circulation had a higher risk factor. The distal arch and descending aorta were then replaced with woven dacron graft. In a chronic type B dissecting aneurysm, the surgical procedure is sometimes complex because of the narrowing of the true lumen and the enlargement of the false lumen or arteries originating from the false lumen to major organs. It is necessary to consider preliminary abdominal reconstruction in cases of 1) dilatation of abdominal aneurysm, 2) obstruction, stenosis or thrombus below the abdominal aorta, or 3) presence of a giant false lumen.

Aged↗

PubMed1997

[A case of successful surgical treatment of recurrent Stanford type A thrombosed aortic dissection].

A 70-year-old female was hospitalized with a complaint of anterior chest pain. Enhanced CT scan demonstrated acute type A aortic dissection with the clotted false lumen. Aortography showed ulcer-like projection in the ascending aorta. The patient received the conservative medical treatment and had been followed up medically at outpatient clinic. One year later, she was admitted with the general malaise, chest discomfort and the enlargement of the mediastinum on the chest X-ray. Aortography revealed recrudescent enlarged false lumen. Graft replacement of the ascending aorta was successfully performed. Careful medical follow up should be necessary for the thrombosed Stanford type A aortic dissections.

Aged↗

PubMed1997

[Simultaneous surgical treatment for distal aortic arch aneurysm associated with innominate artery aneurysm and coronary artery disease].

The patient was 69-year-old male who admitted to our hospital in November 1995 with the complaint of abnormal shadow on chest C-ray. CT scan and aortogram revealed aneurysms of the distal aortic arch and innominate artery. Seventy-five percent stenosis of the right coronary artery was also found in coronary angiogram. The total arch replacement and reconstruction of the innominate artery and CABG to right coronary artery were performed with the aid of cold blood cardioplegia and selective cerebral perfusion and open distal anastomosis. Ascending aorta was used for arterial cannulation to avoid the thromboembolism due to retrograde perfusion from the femoral artery. Satisfactory postoperative course was obtained except transient left hemiplegia and post operative three-dimensional CT scan demonstrated the successful reconstruction. The patient was doing well 8 months postoperatively.

Aged↗

PubMed1997

[Concomitant composite graft replacement of the aortic root and the aortic arch for type A aortic dissection].

Successful surgical treatment of type A aortic dissection with annuloaortic ectasia (AAE) and severely destroyed aortic root was reported. Between April 1991 and April 1996, 26 patients with type A aortic dissection underwent the surgical treatment in our institute. Among those cases, 4 cases (15%) needed the total aortic root replacement with composite graft. Two cases had Marfan syndrome and AAE and aortic regurgitation. Other two cases had severely destroyed aortic root because of the extension and advancement of the dissection to the aortic root. One was the case of disrupted right coronary ostia. And another was the case of frank rupture and massive bleeding from the aortic root during the operation. Cases of AAE were treated successfully by the routine composite graft that was made before the operation. However, the reconstruction of the aortic root for the cases who had destroyed aortic root with normal relation and size of the aortic root was cumbersome because of non displaced coronary artery ostia and the relatively narrow aortic root. For these cases, composite graft was fixed just below the aortic valve annulus by the sutures enforced with Teflon felt strip from the outside of the aorta and it made the reimplantation of the coronary ostia easier. As for the technique of the reimplantation of the coronary ostia, Carrel patch technique was used because good coaptation and fixation of the suture line around the coronary ostia could be obtained with this technique which prevent the complication such as the pseudoaneurysm or the periostial aneurysm formation around the coronary artery in the long term period. Concomitant procedures were aortic arch replacement in all cases, total arch replacement with four vessels graft in 3 cases and hemiarch replacement in 1 case. Each operations were performed with the aid of selective cerebral perfusion and open distal anastomosis.

Aged↗

PubMed1997

[Clinical evaluation of heparin concentration and activated clotting time monitoring (HEPCON HMS) system].

The HEPCON HMS system provides both activated clotting time (ACT) and accurate whole blood heparin concentration measurements. We evaluated the impact of heparin and protamine administration using this system on the incidence and treatment of bleeding after performing a cardiopulmonary bypass. Patients were randomly divided into two groups. Heparin and protamine administration during extracorporeal circulation was determined by classical ACT management in Group A (n = 15) and by HEPCON HMS system in Group H (n = 19). There were no statistical differences in the coagulation factor, the postoperative chest tube drainage or the blood products used between the two groups. Patients in Group H received a higher dosage of heparin and a lower dosage of protamine compared with Group A. By facilitating the maintenance of a therapeutic heparin concentration and by determining an appropriate protamine dosage, the HEPCON HMS system may be useful in managing extracorporeal circulation.

Blood Coagulation Tests↗

PubMed1997

[Experiment in ultra-rapid injection of isotonic sodium chloride after injection of contrast medium: time-density analysis of the aorta and portal vein].

Ultra rapid injection of isotonic sodium chloride after the injection of contrast medium may make it possible to clearly distinguish between the arterial phase and the portal phase. This method could improve the detectability of hepatocellular carcinoma on double phase dynamic spiral CT. A time-density analysis of the aorta and the portal vein was carried out according to the following 2 protocols (5 cases each). In protocol 1, 95 ml of Iopamidol (300 mgI/ml) was injected at a rate of 3 ml/second, while the protocol 2, 40 ml of isotonic sodium chloride was injected at a rate of 10 ml/second after the injection of 60 ml of Iopamidol (300 mgI/ ml) at a rate of 10 ml/second. The duration of the arterial phase (aortic enhancement unit (EU) > or = 200) in protocol 2 was 11 seconds, which was shorter than that in protocol 1. In protocol 2, the duration of the clearly portal dominant phase (reversal phase; aortic EU < portal EU) was about 11 seconds.

Adult↗

PubMed1997

[A case of paraplegia after graft replacement of the ascending aorta and the total aortic arch for the DeBakey type I acute aortic dissection].

A rare case of paraplegia after an emergency operation for DeBakey type I acute aortic dissection was reported. The patient was a 52-year-old female who complained of severe chest and back pain. She underwent graft replacement of the ascending aorta and the total aortic arch. No neurological symptoms were observed before the operation. The cause of the paraplegia was assumed to be a thrombotic occlusion of costal arteries which originated from the false lumen.

Aortic Dissection↗

PubMed1997

[Minimally invasive coronary artery bypass grafting and percutaneous coronary angioplasty in the patient with left main disease and chronic renal failure].

This paper describes the utility of the minimally invasive CAB procedure as an adjuvent therapy to allow angioplasty for left main stenosis. A 73-year-old male who had chronic renal failure and left main coronary disease underwent a combined therapy with minimally invasive CABG and PTCA. The operation was reformed with a 9 cm incision. The fifth costal cartilage was removed. Internal thoracic artery (ITA) was dissected from the left side of the chest wall and anastomosed to the midportion of the left anterior descending coronary artery (LAD) with 7-0 with 7-0 Prolene. He was extubaded a few hours after the operation and resumed his dialysis schedule. On the fifth postoperative day he was electively returned to the catheterization laboratory, where he underwent successful angioplasty of the LMT to Lcx after patency of the LITA-LAD graft had been verified. He was discharged from our hospital ten days postoperatively.

Aged↗

PubMed1996

Inhibition of dynorphin-converting enzymes prolongs the antinociceptive effect of intrathecally administered dynorphin in the mouse formalin test.

The effects of peptidase inhibitors on the antinociceptive induced by intrathecally (i.t.) administered by dynorphin A and dynorphin B in the mouse formalin test were examined. When administered i.t. 5 min before the injection of 0.5% formalin solution into the dorsal surface of a hindpaw, dynorphin A (0.5-2 nmol) and dynorphin B (2-8 nmol) produced a dose-dependent and significant reduction of the paw-licking response. Dynorphin A (2 nmol) and dynorphin B (8 nmol)-induced antinociception disappeared completely within 90 min and 60 min, respectively. p-Hydroxymercuribenzoate, a cysteine proteinase inhibitor, and phosphoramidon, and endopeptidase 24.11 inhibitor simultaneously administered with dynorphin A or dynorphin B. Significantly prolonged antinociception induced by both dynorphins. However, captopril, and angiotensin-converting enzyme inhibitor, bestatin (a general aminopeptidase inhibitor) and a serine proteinase inhibitor phenylmethanesulfonyl fluoride, were active. Dynorphin converting enzyme(s) transform dynorphin-related peptides to [Leu5]enkephalin and [Leu5]enkephalin-Arg6. Neither [Leu5]enkephalin nor [Leu5]enkephalin-Arg6, even at high dose (10 nmol), produced any antinociceptive effect. However, [Leu5[enkephalin-Arg6, but not [Leu5]enkephalin, produced a significant antinociceptive effect when co-administered with phosphoramidon. Therefore, the prolongation of the antinociception induced by both dynorphins in the presence of phosphoramidon, may be due to inhibition of [Leu5]enkephalin-Arg6 degradation. The present results indicate that dynorphin-converting enzyme(s) may be important enzyme(s) responsible for terminating dynorphin-A- and dynorphin-B-induced antinociception at the spinal cord level in mice.

Analgesia↗

PubMed1996

Spinally-mediated behavioural responses evoked by intrathecal high-dose morphine: possible involvement of substance P in the mouse spinal cord.

Intrathecal (i.t.) administration of morphine in the spinal subarachnoid space of mice produced a severe hindlimb scratching followed by biting and licking. The onset of the scratching behaviour was observed 60-70 s after i.t. injection of morphine (60 and 90 nmol), and had a duration of 3-4 min. The morphine-induced behaviour was increased additively by i.t. co-administration of substance P (SP). This characteristic behavioural response was inhibited dose-dependently by i.t. co-administration of the tachykinin NK-1 receptor antagonists, sendide and CP-96,345. Significant antagonistic effects of SP (1-7), a putative antagonist for NK-1 receptors and [D-Phe7, D-His9]SP (6-11), a selective antagonist for SP receptors, were observed against the morphine-induced behaviour. Pretreatment with i.t. SP antiserum and i.t. capsaicin resulted in reduction of the response to morphine. I.t. administration of somatostatin (SOM) antiserum, cysteamine, a relatively selective depletor of SOM and cyclo-SOM, a SOM receptor antagonist, produced no inhibitory effect on the morphine-induced behaviour. These results demonstrate that a spinal system of neurones containing SP may be involved in elicitation of the behavioural episode following i.t. injection of morphine in mice.

Animals↗

PubMed1996

Comparative experimental study of cerebral protection during aortic arch reconstruction.

BACKGROUND: The optimal adjunctive method for cerebral protection during aortic arch repair remains controversial. METHODS: Retrograde cerebral perfusion, selective cerebral perfusion, and hypothermic circulatory arrest were compared in terms of their effect on cerebral function of mongrel dogs using somatosensory evoked potentials. Brain temperatures were held at 20 degrees C for 90 minutes during cerebral perfusion or circulatory arrest and then rewarmed gradually to normal temperature. RESULTS: Somatosensory evoked potentials completely disappeared as soon as retrograde cerebral perfusion or hypothermic circulatory arrest started and did not recover completely. In the selective cerebral perfusion group, it recovered in all cases. Only 2% of cerebral blood flow and about 3% of the cerebral metabolic rate for oxygen were obtained during retrograde cerebral perfusion compared with the preoperative value. The analysis of adenosine triphosphate and water content of the brain supported these results. CONCLUSIONS: Retrograde cerebral perfusion had some advantage for cerebral protection compared with hypothermic circulatory arrest, but could not supply sufficient cerebral blood flow to maintain brain function. Selective cerebral perfusion was the safest method for arch reconstruction that requires cerebral protection for 90 minutes.

Animals↗

PubMed1996

Effect of spinal nitric oxide inhibition on capsaicin-induced nociceptive response.

Pretreatment with the nitric oxide synthase (NOS) inhibitor L-NG-nitro arginine methyl ester (L-NAME), injected intraperitoneally (i.p.) or intrathecally (i.t.), produced a significant antinociception in the mouse assessed by the capsaicin-induced paw licking procedure. Varying the administration time of an effective dose of L-NAME (160nmol, i.t.) resulted in a significant decrease of the brief nociceptive behavioral response induced by capsaicin, even when L-NAME was given 2 hr before capsaicin. L-NAME, injected i.p. or i.t., produced a dose-related reduction in paw licking in the second phase of the formalin (2.0%) response without affecting the first phase. L-Arginine (600 mg/kg, i.p.) but not D-arginine (600 mg/kg, i.p.) reversed the antinociceptive effect of L-NAME in the capsaicin test. Antinociceptive effect of L-NAME, injected i.p. or i.t., was more potent in the second phase response of formalin-induced paw licking than in capsaicin-induced nociceptive response. The inhibitory action of L-NAME was reversed by L-arginine but not D-arginine in the second phase response. L-Arginine alone was without affecting capsaicin- and formalin-induced nociceptive responses. These results suggest that spinal nitric oxide (NO) may be involved in the mechanisms of capsaicin-induced brief nociceptive stimuli, but not in the first, acute phase of the formalin-induced response in mice.

Animals↗

PubMed1996

Involvement of nitric oxide in spinally mediated capsaicin- and glutamate-induced behavioural responses in the mouse.

The intrathecal (i.t.) injection of capsaicin (0.1 nmol/mouse) through a lumbar puncture elicited scratching, biting and licking responses. Pretreatment with the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) (320 nmol), by i.t. injection, resulted in a significant inhibition of the behavioural response produced by i.t. capsaicin (0.1 nmol/mouse). Similar behavioural responses were induced by i.t. injections of NMDA (0.4 nmol), kainate (0.05 nmol) or AMPA (0.05 nmol), which were all inhibited by co-administration of L-NAME (20-80 nmol). L-Arginine (600 mg/kg, i.p.) but not D-arginine (600 mg/kg, i.p.) reversed the inhibitory effect of L-NAME on capsaicin-, NMDA-, kainate- and AMPA-induced behavioural response. Scratching, biting and licking responses induced by tachykinin receptor agonists, substance P, [Sar9,Met(O2)11]substance P, neurokinin A and neurokinin B were not affected by co-administration of L-NAME (40 and 80 nmol). These results suggest that spinal nitric oxide may play a significant role in mechanisms of the behavioural response to capsaicin, probably through the release of glutamate, but not tachykinins.

Animals↗

PubMed1996

[Experimental study of safe limits of retrograde cerebral perfusion].

Safe limits of retrograde cerebral perfusion (RCP) which is now used as an adjunctive method in the surgical treatment of the aortic arch aneurysm were examined experimentally using adult mongrel dogs. After the brain was cooled to 20 degrees C by extracorporeal circulation, RCP was performed from the bilateral maxillary veins, and later, the brain was warmed up to the initial temperature. Experimental groups were divided into two groups; Group I (n = 5) were subjected to cerebral perfusion for 60 minutes, and Group II (n = 8) for 90 minutes. Cerebral function was evaluated using somatosensory evoked potentials (SEP). Cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2) were measured, and histopathological examination was conducted SEP disappeared immediately after the initiation of RCP. In Group I, all the wave forms were recovered by rewarming in every animals, but the amplitude was only 35.0 +/- 16.6% of the preoperational value. In Group II, wave forms were not recovered in 3 animals of 8. CBF during RCP was minimal and about 2% of CBF observed before operation in either group. CMRO2 after being rewarmed up in Group II was lower than that in Group I, but this difference was statistically insignificant. In the histopathological examination, no ischemic change was found in Group I, while many cells indicating ischemic change were found in Group II. These findings indicate that RCP at 20 degrees C could not supply sufficient blood to brain tissues, and the brain can be injured irreversibly when the RCP exceeds more than 60 minutes.

Animals↗