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Biomedical subjects

T Hirata

Publications and source records attributed to T Hirata.

At least 361 records · Page 20Linked to original sources
PubMed1990

[Effects of intra-aortic balloon pumping on mitral flow dynamics after aortocoronary bypass surgery].

Improvement in left ventricular function following intra-aortic balloon pumping (IABP) in 15 patients (aged 51 to 86 years) after coronary artery bypass grafting was evaluated. Using transesophageal atrial echocardiography, the mitral flow velocity integrals in the rapid filling phase (IntR) and in the contraction phase (IntA) were measured from transmitral flow patterns, and the sum of IntR and IntA (IntR + IntA), and the ratios of IntA to IntR (IntA/IntR) were calculated for ON and OFF states of balloon pumping (IABP OFF test). The same parameters were determined during 1:2 assist balloon pumping (IABP 1:2 test); the cardiac cycle with balloon assist was defined as "ON", and that without balloon assist as "OFF". 1. IABP OFF test: IABP increased IntR from 6.4 +/- 1.6 cm to 7.6 +/- 1.9 cm (p less than 0.01), suggesting that a decreased afterload improves left ventricular relaxation. IntA did not change with balloon assist (ON 3.5 +/- 1.2 cm, OFF 3.7 +/- 1.2 cm). IntR + IntA increased from 10.0 +/- 2.0 cm to 11.1 +/- 2.4 cm during IABP (p less than 0.01). IABP reduced the IntA/IntR from 0.62 +/- 0.25 to 0.50 +/- 0.20 (p less than 0.01). The increment in the IntA/IntR without IABP suggests that impaired diastolic filling of the left ventricle due to an increased afterload may be compensated for by enhanced left atrial contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[A case of pulmonary arteriovenous fistula treated by subsegmentectomy with CUSA].

A 35-year-old female who had no symptom was admitted to our hospital because of an abnormal shadow in the middle area of the right lung in a chest X-ray film. The chest tomography, CT and the angiography revealed a pulmonary arteriovenous fistula. It located in the right upper lobe, and was successfully resected by subsegmentectomy of S3b using CUSA. The results indicated that the CUSA was useful in the surgical treatment of the pulmonary arteriovenous fistula which had many vascular anastomoses.

Adult↗
PubMed1990

[Cerebellar infarction: analysis of 33 cases].

During the past 9 years and 2 months we have encountered 33 cases with cerebellar infarction. These patients were classified into 3 types according to their clinical course. Type 1 (18 cases); The course was benign, and symptoms and signs improved without surgical treatment. Type 2 (11 cases); The course was progressive with deterioration of consciousness between 24-72 hours after the onset. Type 3 (4 cases); The course was rapid resulting in lapse into coma within a few hours. Also, its prognosis was fatal due to coexisting brain-stem infarction regardless of any treatment. Surgical intervention was required for Type 2 in which the lesion included the region of the vermis or occupied more than one-third of the cerebellar hemisphere, and had subsequently compressed the brain-stem and caused obstructive hydrocephalus. In 9 cases out of Type 2, ventricular drainage alone was performed and prompt improvement of consciousness level was detected except in one case. We consider that ventricular drainage is not so invasive a method, and it is beneficial. However, in 2 cases of Type 1 and 4 cases of Type 2, hemorrhagic infarction occurred. Thus, one should be aware of the possibility of hemorrhagic infarction, even though it may be asymptomatic infarction. If prompt improvement of consciousness is not detected after ventricular drainage, suboccipital craniectomy should be recommended.

Adult↗
PubMed1990

[Effect of erythromycin on the generation of neutrophil chemiluminescence in vitro].

In order to elucidate the therapeutic mechanisms of low dose-long term erythromycin (EM) therapy in patients with diffuse panbronchiolitis (DPB), the authors evaluated the effect of in vitro EM treatment on neutrophil (PMN) oxygen radicals production. EM has potent capacity to suppress PMN chemiluminescence (CL) induced by the N-formyl Met-leu-phe (FMLP), opsonized zymosan, and calcium ionophore A23187 stimulation. In marked contrast, phorbol myristate acetate (PMA)-induced PMN CL were much less affected by EM treatment. The suppressive activity of EM was dependent on the EM concentration and at a EM concentration of 25 micrograms/ml, FMLP-induced PMN CL were suppressed by 45.3 +/- 5.6% (n = 7), but PMA-induced CL were suppressed only marginally, 11.9 +/- 3.7% (n = 7). The onset of inhibitory activity of EM is rapid and at 5 min., 60.1% of the maximum suppression at 60 min. was observed. This EM-induced suppression was found to be reversible and dependent on the EM-pretreatment temperature since the suppressive activity of EM were observed only at 37 degrees C but not at 0 degrees C. These results suggest that actively transported intracellular EM exerts its suppressive activity by inhibiting the process of Ca++ transfer or Ca++ utilization by cells. In addition, these results were consistent with the concept that EM might act as an anti-inflammatory agent in chronic bacterial airway infections such as bronchiectasis and DPB where the PMN appear to play an important role in the generation of airway destruction.

Erythromycin↗
PubMed1990

[Influences of intra-aortic balloon pumping on superior mesenteric flow dynamics].

The influences of intra-aortic balloon pumping (IABP) on arterial flow of the superior mesenteric artery were assessed by Doppler echocardiography. The subjects were 13 patients postoperatively, requiring IABP support to control low cardiac output state, in which distal aspects of balloons were distal to the superior mesenteric artery. Superior mesenteric flow velocity integral in systole (IntS) and that in diastole (IntD) were measured from superior mesenteric flow pattern, and the sum of IntS and IntD (IntS + IntD) was calculated ON and OFF balloon pumping (IABP ON-OFF test). The same parameters were obtained with balloon inflating on every other beat (IABP 1:2 test); the cardic cycle with balloon assist was defined as "1:2 ON", and that without balloon assist was defined as "1:2 OFF". 1) IABP ON-OFF test. IABP increased IntS from 7.07 +/- 2.56 cm to 9.20 +/- 3.19 cm (p less than 0.05), IntD from 3.00 +/- 1.18 cm to 3.62 +/- 1.40 cm (p less than 0.05), and IntS + IntD from 10.07 +/- 3.48 cm to 12.82 +/- 4.04 cm. Cardiac output increased from 3.89 +/- 1.34 l/min to 4.24 +/- 1.64 l/min with IABP support. The increments in IntS, IntD and IntS + IntD with IABP are attributed, to a large extent, to an increase in cardiac output. 2) IABP 1:2 test. Without balloon inflation, IntS increased (1:2 ON; 7.16 +/- 2.91 cm, 1:2 OFF; 8.41 +/- 3.30 cm, p less than 0.05), and IntD decreased (1:2 ON; 3.51 +/- 1.60 cm, 1:2 OFF; 2.33 +/- 1.25 cm, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[A superficial carcinoma arising from a solitary hepatic cyst].

Reported is a rare superficial papillary adenocarcinoma arising from a congenital cyst, along with a survey of pertinent cases in the world literature. A 43-year-old male with a huge hepatic cyst was admitted to hospital for further examination. Since the cystic drainage done for alcoholic fixation was seromucinous initially but later contaminated by bile, an operation was initiated for dome resection and the closure of the biliary communication. At the time of the deroofing, however, small granulomas were found. And those were confirmed as being malignant by frozen section. Thus, an extended right lobectomy was performed for therapy. From its history and nature, this was considered to be a cancer arising in a congenital hepatic cyst.

Adenocarcinoma, Papillary↗
PubMed1990

[Long-term results of cerebral arteriovenous malformations--surgical and conservative treatment].

During the past 20 years, we have treated 187 cases with cerebral arteriovenous malformations (AVMs). These 134 patients were treated surgically and the remaining 53 patients were managed non-surgically. The purpose of this study is to clarify the surgical indications of AVMs, based on a comparison of the long-term follow-up results between the surgical and nonsurgical groups. Consequently, good results were obtained in the surgical group: the operative mortality was 7.5% and the morbidity was 12.7%. The long-term follow-up results were as follows: Of the 124 followed cases in the surgical group, there were 16 cases with improvement of neurological deficits (13%) and 3 cases with neurological aggravation (2%). Of the 47 followed cases in the nonsurgical group, there were 5 cases with improvement of neurological deficits (11%) and 6 cases with neurological aggravation (13%). As for the incidence of AVM hemorrhage, there were 8 cases with hemorrhage in the nonsurgical group including 4 cases (3 rebleeding cases) which were fatal (11%), in contrast to one case (subtotal resection) in the surgical group. On follow-up angiography, the size of AVMs were unchanged in the majority of cases in the nonsurgical group, with the exception of 2 cases in which there were slight regressions. In the surgical group, on the other hand, enlargement in 2 cases and spontaneous regression in 3 of residual AVM occurred following incomplete resection. Particularly in 2 cases involving unresectable AVMs, a newly formed aneurysm was discovered in the follow-up angiography, emphasizing the fact that serious follow-up angiography is required in cases of untreated AVMs.

Adolescent↗
PubMed1990

[Cerebral blood flow of the non-affected brain in patients with malignant brain tumors as studied by SPECT; with special reference to adverse effects of radiochemotherapy].

The mean cerebral blood flow (mCBF) has been studied in 40 patients with brain tumors undergoing radiation and chemotherapy, and with ages ranging from 20 to 69 years, using 133Xe and single photon emission CT. A comparison was made of mCBF of 40 normal volunteers (34 males and 6 females) whose ages ranged from 25 to 82 years. The results were as follows: Some patients exhibited increased mCBF during external irradiation therapy. Over 3 months after the initiation of external irradiation, the average mCBF decreased significantly, ranging from 5.0 to 8.8 ml/100g/min, compared to the control group. A regression equation, which was obtained using multiple regression analysis, was delta mCBF = -3.140 + 0.181 A - 0.069 E - 0.022 V - 0.543 C (delta mCBF: subtract measured mCBF from presumed mCBF at the same age, A: age, E: dose of external irradiation, V: volume of lesion, C: CSF-cranial ratio, multiple regression coefficient: r = 0.536, P less than 0.002). This result means that the mCBF of non-affected hemispheres decreases in direct proportion to the volume of the lesion, degree of brain atrophy, and dose of external irradiation. In this study, the tendency for mCBF to decrease in direct proportion to these factors was found to be more pronounced among young patients. There were no side effects caused by the additional irradiated doses intraoperatively or caused by residual tumors on the mCBF of non-affected brains. Also, there was no significant difference in the average mCBF between cases in which whole and local brain irradiation was employed, as well as between cases in which there were different histopathological diagnoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Malignant cerebellar astrocytic tumours in children.

The authors reviewed 5 cases of histopathologically verified malignant cerebellar astrocytic tumours (2 anaplastic astrocytomas and 3 glioblastomas) in children admitted to our department. All cases exhibited symptoms and signs of increased intracranial pressure and of a cerebellar lesion. Brain stem symptoms were present in 4 cases. All of the tumours were located in or near the midline of the cerebellum with no large cyst. Surgical removal (70 to 90% removal) of the tumour was performed in 4 cases. In one case only a biopsy was done. Even with subsequent follow-up treatment including radiotherapy, chemotherapy, and/or immunotherapy, the course of the disease could not be reversed, and all of the children died 3 to 13 months (mean 7 months) after admission due to tumour re-growth or recurrence. Tumour dissemination along the walls of the ventricular system was seen in 2 cases, and was considered to be a peculiar, fatal form of tumour recurrence in patients with this type of tumour. Malignant cerebellar astrocytic tumours in children have an extremely poor prognosis. Until, improved therapy is available to counteract this tragic consequence, it will remain so.

Adolescent↗
PubMed1989

Intrahepatic biliary cysts after hepatic portoenterostomy in four children with biliary atresia.

We report our experience with 4 cases of cystic dilatation of intrahepatic bile ducts following hepatic portoenterostomy for biliary atresia. Two of the cases did not achieve satisfactory bile excretion and all four cases developed recurrent cholangitis after hepatic portoenterostomy. The attacks of cholangitis seemed to be associated with the presence of intrahepatic cysts. Although one case resulted in death from hepatic failure, three other cases are now outpatients. Patients who develop recurrent cholangitis following hepatic portoenterostomy, should be examined to exclude the presence of intrahepatic biliary cysts. Ultrasonography, computed tomography and percutaneous transhepatic cholangiography were all effective in detecting cysts and provided valuable information for planning treatment. Percutaneous transhepatic or surgical drainage of the bile ducts was effective in reducing jaundice, and recurrent cholangitis.

Bile Duct Diseases↗
PubMed1989

Resection of carcinoma in the cervical esophagus following prior removal of a thoracic esophageal carcinoma--a case report.

We report herein, a rare case of a patient who, having undergone resection of a thoracic esophageal cancer, underwent removal of a cervical esophageal cancer, for which a free jejunal graft with microvascular anastomoses was utilized. The tumor in the cervical esophagus had originated from a second primary squamous cell cancer, which had occurred synchronously but had unfortunately escaped detection before the first operation. Due to the high incidence of other multicentric neoplasma or metastatic skip lesions accompanying esophageal carcinoma, careful evaluation during preoperative examinations in order to avoid overlooking another lesion, especially in the cervical portion of the esophagus is imperative.

Carcinoma, Squamous Cell↗
PubMed1989

Human acute lymphoblastic leukemia cell lines with characteristics of intraclonal variation in B-cell differentiation stage.

The acute lymphoblastic cell lines designated BAL-KHc and BAL-KHs were established from the peripheral blood of a Japanese female patient with a B-cell acute lymphoblastic leukemia. The BAL-KHc and BAL-KHs exhibited B-cell characteristics with positive cell markers for CD19, CD20, CD21 and HLA-DR antigens. Immunoglobulin with gamma and kappa chains was demonstrated on the cultured and fresh leukemia cells respectively. The cells lacked the Epstein-Barr virus genome and expressed abnormal chromosome constitutions including a t(8;14)(q24;q32). These results suggested that the cell lines present B-cell characteristics. The BAL-KHc cells showed different cell growth characteristics and cell surface marker profile compared to those of the BAL-KHs. These variations suggest that the BAL-KHc cells were probably frozen at a different stage of B-cell maturation from those of BAL-KHs, although both cell lines originated from the cells in the same peripheral blood sample of the patient.

Aged↗
PubMed1989

Lipomas of the peripheral lung--a case report and review of the literature.

Bronchial lipomas are uncommon benign neoplasms of the lung and the number of these tumours is only 109 cases in the international literature (108 cases reported in English and one in German) up to date. Moreover, most of the tumours occur in the proximal portions of lobar or segmental bronchi: the references in the literature to peripheral lipoma of the lung make up only 6 cases. Peripheral lipomas of the lung are thought to originate from fatty tissue in the wall of peripheral bronchi. We present a further case of peripheral lipoma and analyze the reported 7 cases.

Adult↗
PubMed1989

Analysis of reruptured cerebral aneurysms and the prophylactic effects of barbiturate therapy on the early stage.

During the past seven years, we have studied 661 cases of ruptured intracranial aneurysms. Rebleeding occurred in 65 cases (10%) and, within this group, 43 cases (70%) rebled within the first 6 hours after initial subarachnoid haemorrhage (SAH). Analysis of these 43 cases led to the following conclusions: 22 patients incurred rebleeding from causes such as transfer (6 cases), neuroradiological examinations (13 cases), and tracheal intubation during anaesthesia etc. (3 cases), while no special causative factors were discovered in the other 21 cases. Rebleeding occurred in 19 patients even while on absolute bed rest and in 11 patients who had induced systemic arterial hypotension (under 140 mmHg) through treatment. Six cases experienced rebleeding while undergoing angiography within 6 hours after the first subarachnoid haemorrhage. Eight of 17 reruptured anterior cerebral complex (Acom) aneurysm cases and 8 of 11 reruptured middle cerebral artery (MCA) aneurysm cases had an intracerebral haematoma on initial CT-scan following the first attack, demonstrating that the risk of rebleeding was very high in cases of intracerebral haematoma. The mortality rate for these rebleeding cases was high i.e. 65%. Therefore, because the time factor could precipitate rebleeding, early transfer and operation was considered optimal for minimizing rebleeding soon after an aneurysm rupture, even though angiography within 6 hours of the first SAH was a serious risk. Barbiturate therapy, performed as early as possible for serious cases, was considered to be effective in preventing rebleeding.

Adult↗
PubMed1989

Synthesis and biological evaluation of 3-chloro-1-carbacephem compounds.

The 3-chloro-1-carbacephem nucleus was prepared for the first time from a 3H-1-carbacephem compound through a sequence of reactions involving addition of thiophenol, oxidation of sulfide to sulfoxide, and alpha-chlorination of the sulfoxide, followed by elimination of phenylsulfinic acid. The 2-beta-methyl analog was similarly prepared, but the 2 alpha-methyl analog was not obtained. Optical resolution of the 3-chloro-1-carbacephem compound was achieved by the employment of penicillin acylase. That is, the 7-phenylacetamido derivative was enantioselectively hydrolyzed to afford the optically active 7-amino-3-chloro-1-carbacephem compound. Carbacefaclor, the carbacephem analog of cefaclor, was directly and efficiently prepared by enzymatic phenylglycylation of the racemic 7-amino-3-chloro-1-carbacephem compound by using immobilized penicillin acylase. Carbacefaclor thus prepared exhibited comparable antibacterial activity against most gram positive bacteria tested and higher activity against typical gram negative bacteria as compared with cefaclor. Moreover, carbacefaclor possessed remarkably high chemical stability.

Cephalosporins↗
PubMed1989

Synthesis and biological evaluation of optically active 3-H-1-carbacephem compounds.

3-H-1-Carbacephem nuclei with or without a 2 alpha- or 2 beta-methyl group were prepared via 2 + 2 cycloaddition followed by intramolecular Horner-Emmons cyclization. Optically active 3-H-1-carbacephem compounds were efficiently prepared by employing a penicillin acylase-producing microorganism in two ways. That is, the 7-phenylacetamide of a racemic carbacephem nucleus was hydrolyzed enantioselectively with the enzyme to afford the optically pure nucleus, which was then acylated to give antimicrobial compounds. Alternatively, a racemic carbacephem nucleus was directly and enantioselectively phenylglycylated with the enzyme. 3-H-1-Carbacephem nuclei appeared to be better substrates for penicillin acylase than penam or cephem nuclei of natural origin. 3-H-1-Carbacephem compounds showed potent antimicrobial activity; compound 32a exhibited activity comparable to that of ceftizoxime, a cephem analog with the same acyl group. It is of interest that the 3-H-1-carbacephem compound turned out to have more potent antimicrobial activity than its 3-substituted methyl analog.

Bacteria↗