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Biomedical subjects

T Hirata

Publications and source records attributed to T Hirata.

At least 217 records · Page 12Linked to original sources

Role of adenosine in blood flow in the rat intestine.

We examined the relation between adenosine production and increased blood flow. For this purpose, we used a sensor holding system with a laser Doppler blood flowmeter. The elevation of blood flow was observed by administration of adenosine. Therefore, when AMP was administered to the rats, the elevation of blood flow rate was observed. These results suggest that AMP is rapidly transported to the adenosine active site by ecto-5'-nucleotidase.

5'-Nucleotidase↗

[Natural killer cell lymphoma having a nodular shadow in the lung as an initial finding, developed to leukemia complicated with hemophagocytic syndrome at the time of relapse].

A 57-year-old female was admitted to Uji hospital for the further evaluation of nodular shadow on her right lung. During the period of admission, she developed cervical lymph node swelling. She was diagnosed as having malignant lymphoma (diffuse, small cleaved cell) by lymph node biopsy. She received combined chemotherapy and obtained partial remission for seven months until she developed fever and pancytopenia. Laboratory data showed increased number of large granular lymphocytes (LGLs) in blood. Bone marrow revealed increased number of LGLs with hemophagocytosis by macrophage. Surface marker analysis revealed LGLs were positive for CD2 CD16, and CD56 and negative for CD3, CD4, CD8, and CD20. T-cell receptor genes beta and gamma were in germ line configuration. Analysis of Epstein-Barr virus genome using termini probe indicated a monoclonal proliferation of LGLs. Reexamination of the biopsy specimen of lymph node revealed LGLs which was negative for CD3 and CD20. The patient was diagnosed as a leukemic phase of natural killer (NK) cell lymphoma complicated with hemophagocytic syndrome (HPS). Serum levels of interferon-gamma, macrophage colony-stimulating factor, granulocyte colony-stimulating factor, and interleukin-6 increased, which might be related to HPS.

Antigens, CD↗

[Diagnosis and surgical treatment of metastatic lung tumors].

To investigate the chance of discovery of metastatic lung tumors and the five-year survival rates of patients undergoing surgical resection, we followed 99 patients who underwent initial surgical treatment at our hospital between 1979 and 1996. With regard to primary organs or sites, 32 patients had rectal cancer, 27 patients had breast cancer, 19 patients had colon cancer and 21 patients had osteosarcoma. For 22 of 99 patients (22%), discovery was due to subjective symptoms such as cough and sputum (n = 12), chest (or back) pain (n = 7) or hemosputum (n = 5). Ten of 19 patients (53%) with colon cancer experienced subjective symptoms which led to the discovery of metastases. In 76 of 99 patients (78%), metastatic lung lesions were not discovered through subjective symptoms. In 63 of those 76 patients, such lesions were initially found by plain chest roentgenography or CT. In 20 of 21 patients (95%) who had osteosarcoma, metastatic lung tumors were discovered by chest roentgenography or CT. In 14 of 76 patients, all of whom had metastatic lung carcinomas, the lesions were discovered through elevated levels of tumor markers. Therefore the importance of periodic chest roentgenography and tumor marker testing was demonstrated. Disease-free interval (DFI) was over six years in five of 32 patients (16%) with rectal cancer and 13 of 27 (48%) with breast cancer. DFI was less than five years for 15 of 19 patients (79%) with colon cancer, and less than two years for 16 of 21 (75%) with osteosarcoma. Thus, DFI differed according to the sites of the tumors. The five-year survival rates of 97 patients were examined. Patients were divided according to the sites of their primary tumors, and then subdivided according to the type of surgery they received. Patients were thus divided into five categories: I) those who underwent incomplete resection of metastatic lung lesions, II) those who underwent complete resection of both pulmonary lesions and involved mediastinal lymph nodes, III) those who had undergone previous treatment for tumors in organs other than the lung, IV) those who underwent complete resection of multiple lung lesions, and V) those who underwent complete resection of solitary lung lesions. For all primary sites, none of the patients in group I) survived for more than two years. Therefore complete resection seems very important for the treatment of metastatic lung tumors. With regard to the other groups, several facts were noted. For rectal cancer, the five-year survival rate of groups V) and III) was 55.6% in either case. Therefore complete resection of rectal cancer metastatic to the lung may improve the five-year survival rate even for patients who have previously been treated for cancers in organs other than the lung. For colon cancer, the five-year survival rate of group V) was 51.4%. Complete resection of only a solitary lung lesion may improve the five-year survival rate for colon cancer. For breast cancer, the five-year survival rate of group V) was 37.5% and that of group II) was 60.0%. This may indicate that for patients who have both pulmonary lesions and mediastinal lymph node involvement, complete resection of both is important. For osteosarcoma the five-year survival rate of group IV) was 26.0%. Thus, osteosarcoma patients have a chance of survival if they undergo complete resection of lung metastases.

Adolescent↗

In vivo monitoring of .OH generation on jejunal ischemic injury by dialysis technique.

We applied an in vivo microdialysis technique to examine free radical generation following ischemic injury in the rat jejunum. For this purpose, we used a microdialysis probe holding system. The salicylate reacts with hydroxyl free radical (.OH) and generates 2,3-dihydroxybenzoic acid (DHBA), which can be measured electrochemically in picomole amounts by high-performance liquid chromatography (HPLC). Therefore, the former was used for trapping the .OH formation. Reperfusion of the jejunum produced progressive elevations in the levels of 2,3-DHBA achieving the maximums at 20 min, after which they decreased progressively to the baseline. These elevations were significant only after 10 min- and 20 min-ischemia. However, this change was not significant in the case of 30 min-ischemia. Ischemia-reperfusion of rat intestine caused morphological changes. These results suggest that .OH production is significantly reduced after 30 min-ischemia providing thus the possibility for more severe intestinal damage. In conclusion our dialysis probe can be useful for the measurement of .OH generation following ischemia-reperfusion injury.

Animals↗

[Cardiac surgery using cardiopulmonary bypass in a patient with sickle-cell trait].

The sickle-cell gene is most concentrated in West Central Africa, the northeast corner of Saudi Arabia and East Central India. Sickle cell trait is the heterozygous condition for Hb S gene. Thirty to fifty per cent of their hemoglobin is Hb S and the remainder is Hb A. The sickle-cell crisis is induced by hypoxia, hypercarbia, acidosis, low flow condition, and hypothermia, which leads to vasoocclusion. A 39-year-old black man from Burkina Faso located in West Africa with left ventricular rupture was admitted for operation using cardiopulmonary bypass (CPB). He had been diagnosed as sickle-cell trait. The Hb S concentration was 36.2 per cent before operation with hemoglobin electrophoresis. During CPB, the minimum blood temperature was 31 degrees C and an aortic cross-clamp was not done. Total CPB time was 1 hour 31 minutes. Use of vasodilator and hyperventilation was effective. No neurological sequelae were observed.

Adult↗

[Cheiro-oral syndrome following a cortical brain infarction in the precentral gyrus and at the base of the central sulcus. A case report].

We report a patient who manifested cheiro-oral syndrome following a cortical brain infarction without involvement of postcentral gyrus. A 67-year-old man was admitted to our hospital because of sudden paresthesia in his right face and right thumb and index finger. His cranial magnetic resonance imaging disclosed that the infarction was located in the left precentral sulcus and at the base of the central sulcus, while the left postcentral gyrus was not involved. His sensory symptom was attributed to the lesion of the Brodmann's area 3a, which is located at the base of the central sulcus. We postulate that the lesions responsible for cortical cheiro-oral syndrome are dispersed more widely than those for thalamic or pontine ones, since the somatotopy of face and hand in the cortex is distributed more extensively than that in the thalamus or pons.

Aged↗

Blood flow rate in jejunal ischemia-reperfusion injury.

We examined changes in the blood flow rate in the course of jejunal ischemic injury using a laser Doppler flowmeter. For this purpose, we designed a sensor holding system, which involved the fixation of the sensor to the jejunum and allowed their movements to be synchronized. When the jejunum was reperfused after 10 min of ischemia, the blood flow rate markedly increased and then gradually decreased to the initial level. A 30-min period of ischemia produced the slowest recovery of the blood flow rate. This system could be useful for monitoring the blood flow rate in different anatomical regions.

Animals↗

Characterization of the binding site for cyclothialidine on the B subunit of DNA gyrase.

The mechanism of inhibition of DNA gyrase by cyclothialidine, a novel gyrase inhibitor isolated from Streptomyces filipinensis NR0484, has been studied further by using [14C]benzoylcyclothialidine and a reconstituted Escherichia coli gyrase system consisting of the A subunit, the B subunit and relaxed ColE1 DNA. The mechanism of inhibition was also studied with the 43-kDa N-terminal fragment of the B subunit. The [14C]benzoylcyclothialidine could bind to the B subunit alone but not to the A subunit nor to the plasmid DNA alone. Furthermore, the compound also bound to the 43-kDa N-terminal fragment of the B subunit. Scatchard analysis of [14C]benzoylcyclothialidine binding to DNA gyrase showed that the binding affinity of the compound increased, depending on the assembly of the gyrase (A2B2). DNA complex. This suggests that the binding site of cyclothialidine on the B subunit or its vicinity causes a conformational change during the assembly of the gyrase.DNA complex (increase in affinity: B-->A2B2-->A2B2.DNA). Furthermore, displacement curves of [14C]benzoylcyclothialidine binding by nonlabeled cyclothialidine, ATP analogues, and coumarin antibiotics indicated that cyclothialidine, coumarins, and ATP share a common (or overlapping) site of action on the B subunit of DNA gyrase; however, the microenvironment of the binding sites may differ.

Adenosine Triphosphatases↗

Characterization of c-kit-positive neurons in the dorsal root ganglion of mouse.

Previously, we showed that c-kit receptor tyrosine kinase is expressed by a subpopulation of dorsal root ganglion (DRG) neurons, and that the ligand for the c-kit receptor, stem cell factor (SCF), induces the neurite outgrowth and supports the survival of these neurons in culture [16]. However, it is unknown which class of DRG neurons express c-kit receptor and which factor regulates differentiation and survival of c-kit-positive neurons. In the present study, we attempted to characterize c-kit positive neurons in the mouse DRG. The c-kit-positive neurons were small or medium in size, and 44% of these neurons contained substance P. Central fibers of the c-kit-positive neurons terminated in laminae I and II of the gray matter of the spinal cord. These results suggest that c-kit-positive neurons in the DRG belong to a functional subpopulation. The c-kit receptor protein was presented on the membrane of processes and growth cones in neurons. When DRG cells of embryonic day 15.5 or 17.5 were cultured, the survival of c-kit-positive neurons was supported by SCF, nerve growth factor (NGF) or leukemia inhibitory factor. SCF and NGF synergistically supported the survival of c-kit-positive neurons at submaximal concentrations. c-kit-positive DRG neurons from neonatal mice survived without addition of any factor in culture, suggesting that the requirement for trophic support in c-kit-positive neurons changes during development.

Age Factors↗

Efficacy of the quinocarmycins KW2152 and DX-52-1 against human melanoma lines growing in culture kand in mice.

Quinocarmycin monicitrate (KW2152) and its analogue, DX-52-1, demonstrated specificity for melanomas in the National Cancer Institute in vitro human tumor cell line drug screen. In contrast to most cell lines, a 50% reduction in tumor cell burden (as measured protein) at the end of a 48-h drug incubation was produced in five of eight melanoma lines by KW2152 concentrations (LC50s) ranging from 0.49 to 10.93 microM and by DX-52-1 concentrations ranging from 0.71 to 7.33 microM. Using the COMPARE algorithm, the patterns of differential cytotoxicity for both agents at the LC50 level of effect most closely resembled those for actinomycin D, mithramycin, and Adriamycin. In in vivo studies, both KW2152 (40 mg/kg/day) and DX-52-1 (90 mg/kg/day) caused partial and complete regressions of staged s.c.-implanted LOX IMVI melanoma xenografts following i.p. administration on days 5, 9, and 13 and produced tumor growth delays of 231 and 181%, respectively (P < 0.001). Activity was augmented by more prolonged therapy. Statistically significant growth inhibition of SK-MEL-2, UACC-62, UACC-257, and M14, but not SK-MEL-5 and MALME-3M, melanoma xenografts also was observed following every fourth or seventh day i.p. treatments. Based on these findings, DX-52-1 has been selected by the National Cancer Institute for development to clinical trial especially against melanomas. This agent represents one of the first to be selected for preclinical development based on disease-panel specificity discovered in the National Cancer Institute cancer drug screen.

Animals↗

Role of ultrasound in managing neuroblastoma detected by mass screening: a proposed ultrasonographic grading for children with neuroblastoma.

The ultrasonographic (US) findings of 25 infant cases detected by the Japanese mass screening program for neuroblastoma (NB) were reviewed. The following results were obtained: An identification of the primary site was possible in 96% of the cases with abdominal US. An estimation of the tumor weight was possible based on the mass volume, which was calculated from US measurements. With the combination of the estimated mass volume, local involvement, and distant metastasis, the US grading of NB was possible and closely corresponded to the surgical staging (84%). The NB cases of adrenal origin at U1a, with a mass volume of less than 16 mL, were all found to be stage I and presented the possibility for spontaneous regression.

Adrenal Gland Neoplasms↗

Expression of the adult T-cell leukemia-derived factor, human thioredoxin, in the allotransplanted canine lung.

The relationship between the expression of adult T-cell leukemia-derived factor, human thioredoxin (ADF/TRX), and rejection in transplanted canine lungs was investigated in this study. Of a total 27 adult mongrel dogs, 24 underwent allotransplantation of the left lung with no immunosuppressant and the other three underwent autotransplantation of the left lung. Of the allotransplanted dogs, five were killed on postoperative day (POD) 1, five on POD 2, seven on POD 3, and seven on POD 5, while all three autotransplanted dogs were killed on POD 5. Histological examination was performed on the 24 allotransplanted left lungs (group A), 12 autologous right lungs (group B), and bilateral lungs of the three autotransplanted dogs (group C). The lung tissue was stained with anti-ADF antibody, and the high-ADF-producing cells (ADFh cells) in a randomly chosen field were counted as an index of ADF expression. As the signs of rejection in the group A lungs became more severe with time, the ADFh cells increased in number: 1.68 +/- 1.15, 6.08 +/- 3.44, 14.03 +/- 6.09, and 47.74 +/- 18.89, on PODs 1, 2, 3, and 5, respectively. However, the number of ADFh cells in the group B and group C lungs did not become significantly different from that on POD 1 in group A. These results suggested that ADF/TRX expression may be useful for the early diagnosis of rejection of transplanted lungs.

Animals↗

Patent ductus venosus associated with a hyperintense globus pallidum on T1-weighted magnetic resonance imaging and pulmonary hypertension.

UNLABELLED: We report the case of a 13-year-old Japanese boy with a patent ductus venosus. He experienced mild disorientation and hallucination at age 8 years. Hyperammonaemia was discovered at age 12 years. Brain MRI demonstrated multiple intracranial hyperintense lesions, mainly in the globus pallidum, which suggested portosystemic encephalopathy. Patent ductus venosus was demonstrated by abdominal ultrasonography and angiography. Cardiopulmonary investigation revealed pulmonary hypertension. An intracranial hyperintense lesion observed on T1-weighted MRI may be an initial clue for discovering a patent ductus venosus in asymptomatic patients. CONCLUSION: When patent ductus venosus is disclosed, pulmonary hypertension should be sought, as in cases with other portosystemic shunts.

Adolescent↗

Prognostic significance of an interface pattern of central fibrosis and tumor cells in peripheral adenocarcinoma of the lung.

Fifty-nine surgically resected pulmonary adenocarcinomas were histologically classified into four types (A, B, C, and D) according to the pattern of invasion, ie, the extent of invasive tumor cell growth in the interface zone between alveoli replaced by cancer cells and the central region of fibrosis (so-called "scar"). In pattern A cancer cells proliferate along the alveolar walls without forming a frankly invasive lesion. In pattern B invasive lesions occupy less than 30% and in pattern C more than 30% of the fibrosing area. Pattern D refers to invasion of the bronchial lumen by cancer cells. The 59 tumors included 14 of pattern A, 12 of pattern B, 16 of pattern C, and 17 of pattern D. The 5-year survival rate for patients with pattern A tumors was 100%, and the rates for patients with pattern B, C, and D tumors were 64.2%, 30.0%, and 11.8%, respectively. Each difference between pairs of survival curves was statistically significant (P < .05). We found a correlation between the pattern of invasion and other prognostic factors. However, even in the cases evaluated as favorable by other prognostic factors (stage I, tumor less than 35 mm in diameter, negative for lymph node metastases, well-differentiated histology, negative for subpleural invasion, negative for vascular invasion) the survival curves became steeper going from pattern A to patterns B, C, and D. We conclude that the pattern of invasion is correlated with the prognosis of surgically treated patients. Our study may provide new histological criteria for the prognostic evaluation of pulmonary adenocarcinoma.

Adenocarcinoma↗

Surgical treatment of small cell carcinoma of the lung: advantage of preoperative chemotherapy.

To assess the effect of chemotherapy on postoperative survival of patients with small cell lung carcinoma (SCLC), 46 patients who underwent surgery at Kyoto University between 1976 and 1991 were retrospectively reviewed. Seventeen patients (37.0%) received chemotherapy prior to as well as after surgery (neoadjuvant therapy group), 23 (50.5%) received chemotherapy only after surgery (adjuvant therapy group), and the other six received no chemotherapy (non-chemotherapy group). The 5-year survival rate of patients with c-Stage I or II disease in the neoadjuvant therapy group was as high as 80.0%, which seemed to be higher, although with no statistical significance, than that in the adjuvant therapy group (37.7%, P = 0.10). The 5-year survival rate of patients with c-Stage III (IIIa or IIIb) disease in the neoadjuvant therapy group, although not satisfactory (10.0%), was significantly higher than that in the adjuvant therapy group (0.0%, P = 0.04). No patients in the non-chemotherapy group had survived 5 years. Moreover, multivariate analysis showed that failure to employ preoperative chemotherapy was the strongest prognostic factor causing a poor prognosis (P = 0.01). On the other hand, eight (30.8%) out of 26 patients with c-Stage I or II disease postoperatively proved to have mediastinal lymph node involvement (pN2-3), and two (7.7%) proved to have intrapulmonary metastasis (PM). Considering the advantage of preoperative chemotherapy and the discrepancy between c- and p-stage, sufficient chemotherapy prior to surgery should be employed, and may realize a good prognosis in patients with c-Stage I or II disease. In contrast, patients with c-Stage III disease are not appropriate as candidates for surgery even if preoperative chemotherapy is performed.

Aged↗

Evaluation of cases with combined bronchoplasty and pulmonary arterioplasty for the treatment of lung cancer.

Bronchoplasty and pulmonary angioplasty(PA-plasty) have been performed in recent years for lung cancer invading the bronchus and pulmonary artery. We evaluated the results and complications in patients who underwent such operations. There were 23 cases of bronchoplasty performed between 1988 and October 1993. Of these 23 cases, 9 underwent PA-plasty with bronchoplasty. There were 8 males and 1 female (mean 65.6 year-old). There were 8 patients with primary lung cancer(sq 5, ad 1, la 1, and sm 1) and 1 with metastatic lung tumor of colon cancer. One patient was in p-stage II, 6 in p-stage III, and 1 in p-stage IV. Seven patients underwent right upper lobectomy, 1 did the right upper and middle bilobectomy, and 1 did a left upper lobectomy. Bronchoplasty was performed using sleeve resection in 8 patients, and a wedge resection in 1 patient. PA-plasty was performed using sleeve resection and end to end anastomosis in 2 cases, and using side wall resection and plasty in 7 patients after clamp. Of 9 patients in whom both broncho- and PA-plasty were performed, there was one with the resected bronchial stump of cancer-positive. Total resection of the cancer was possible in the remaining 8 patients. Postoperative complications included 2 pneumonia, 2 empyema, and 1 each, acute cardiac failure, pulmonary thrombus, and chylothorax. The patients with empyema required re-operation using omentopexy or thoracoplasty. Long-term results showed that 2 patients died because of recurrence. Another patient died of respiratory failure. The remaining 6 patients were alive without any evidence of cancer. Pneumonectomy was avoided and the combination of PA-plasty and bronchoplasty was performed instead. However, the incidence of postoperative complications was high, indicating that utmost care must be exercised in the postoperative management of these patients.

Adenocarcinoma↗