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Biomedical subjects

T Obara

Publications and source records attributed to T Obara.

At least 163 records · Page 9Linked to original sources
PubMed1992

[A rare case of mediastinal neuroblastoma with pectus excavatum in a 4-month-old boy--a surgical report].

Screening of neuroblastoma is commonly performed on 6-month-old infants; therefore, its discovery in children younger than that age is extremely rare. However, a 4-month-old boy with pectus excavatum was found to also have mediastinal neuroblastoma after close examination. This 7 kg child had no apparent symptoms, yet revealed an egg-sized shadow along the right atrium in the chest X-ray film, and along the right side of the vertebrae on CT. Due to the increase in the size of the tumor after two months of observation, we suspected malignant neurogenic tumor and performed a thoracotomy. With a right posterolateral thoracotomy we removed the dark-brown, elastic tumor measuring 6 x 4 x 3 cm and located along the right side of the vertebrae from III through VIII ribs. The origin was the thoracic sympathicus and the pathological diagnosis of the tumor was neuroblastoma with rosset formation. After conducting a post-operative chemotherapy (Jame's protocol), no evidence of recurrence was observed at 33 months after surgical treatment. We summarized the previously reported seven surgically treated cases of Stage I mediastinal neuroblastoma at less than 12 months of age. Among the 2500 pectus excavatum surgeries that have been held at our department, non has been found to have mediastinal neuroblastoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[Analysis of coagulation factor XIII in Crohn's disease--establishment of a novel monoclonal anti-coagulation factor XIII antibody].

A novel monoclonal anti-human coagulation factor XIII (F. XIII) antibody (2C3 antibody) raised in BALB/c mice was established by Kohler and Milstein methods. The monoclonal antibody recognized F. XIII of 85 KD demonstrated by western blotting analysis. Plasma F. XIII-IR levels measured by ELISA with 2C3 antibody were significantly lower in active disease than in quiescent disease in a total of 21 Crohn's disease (CD) patients. Plasma F. XIII levels were significantly lower on admission in CD with fistulas than in CD without fistulas. Relationships between activities of CD and plasma F. XIII levels were shown. No significant relationships, however, were observed between F. XIII-IR levels and nutritional states assessed by TP, ALB, TF, PA, RBP, %IBW. Low levels of F. XIII in active CD patients with fistulas may occur regardless of hyponutrition. By using 2C3 antibody, global functions of F. XIII will become clarified as well as pathologic and diagnostic roles of plasma F. XIII in CD.

Adolescent↗
PubMed1991

Isolation and characterization of a gene encoding a G-protein alpha subunit from Schizosaccharomyces pombe: involvement in mating and sporulation pathways.

The gpal gene of Schizosaccharomyces pombe, which encodes a protein homologous with the alpha subunits of mammalian guanine nucleotide-binding proteins (G proteins), was isolated by cross-hybridization using rat Gi1 alpha and Gx alpha cDNA. The deduced amino acid sequence was about 37% identical with rat Gi1 alpha and Gx alpha proteins and contained three conserved motifs commonly found in all GTP-binding proteins. Disruption of gpa1 was not lethal but conferred sterility and sporulation deficiency on Sch. pombe cells. Thus, the gene is essential for the sexual development and is probably coupled to mating-factor receptors. In contrast to Saccharomyces cerevisiae GPA1, which plays a negative role in mating-factor signal transduction, Sch. pombe gpa1+ apparently has a positive function. A gpa1 transcript of 2.2 kilobases was detected in vegetatively growing cells. A 1.6-kilobase gpa1 transcript appeared in addition to the 2.2-kilobase transcript when cells were derepressed for mating or meiosis.

Amino Acid Sequence↗
PubMed1991

Effects of transforming growth factor-beta released from gastric carcinoma cells on the contraction of collagen-matrix gels containing fibroblasts.

To investigate the mechanisms underlying contraction of the stomach wall in cases of gastric scirrhous carcinoma, we have developed an in vitro model for gastric cancer, in which both fibroblasts and gastric carcinoma cells are embedded within a collagen matrix. Gastric carcinoma cells of the scirrhous type (KATO-III) but not the nonscirrhous type (MKN-28) markedly enhanced the ability of human intestine, human lip, and mouse kidney fibroblasts to contract collagen gels. KATO-III cells released transforming growth factor-beta (TGF-beta) into culture media in an activated form, whereas the MKN-28 cells produced a latent form. The role of TGF-beta produced by gastric cancer cells from the scirrhous type was clarified by adding TGF-beta (receptor grade) into collagen gels embedded with fibroblasts, contraction being enhanced. Other growth factors tested, including transforming growth factor-alpha and epidermal growth factor, did not enhance the contraction of collagen gels containing embedded human and rodent fibroblasts. These results suggest that the activated form of TGF-beta released from gastric scirrhous carcinoma cells stimulates fibroblasts to contract the collagenous stroma of the stomach wall, which leads to the so-called "linitis plastica" stomach condition.

Adenocarcinoma, Scirrhous↗
PubMed1991

Apolipoprotein A-I deficiency due to a codon 84 nonsense mutation of the apolipoprotein A-I gene.

The molecular genetic defect of a female patient with apolipoprotein A-I (apoA-I) deficiency and premature atherosclerosis was examined. Her parents were first cousins. Her plasma density fraction from 1.063 to 1.21 g/ml contained no apoA-I on SDS/PAGE and no measurable high density lipoprotein cholesterol. Southern blot hybridization showed no gross abnormality to be present in the patient's apoA-I gene and homozygosity for a haplotype of restriction fragment length polymorphisms in the apoA-I gene region. Sequencing after amplification by PCR revealed a codon 84 nonsense mutation (CAG----TAG, Gln----stop) of exon 4 and a codon 67 missense mutation (GCC----ACC, Ala----Thr) of exon 3 in the patient's apoA-I gene. The data from dot-blot hybridization with allele-specific oligonucleotide probes indicated that she was homozygous for the apoA-I gene with regard to the two mutations. The codon 37 missense mutation was also detected in the apoA-I gene of 6 out of 60 controls, who all had normal levels of apoA-I and high density lipoprotein cholesterol, suggesting that the missense mutation is polymorphic and not associated with apoA-I deficiency. These findings indicate that homozygosity for the apoA-I gene with codon 84 nonsense mutation causes the deficiency of apoA-I and of high density lipoprotein cholesterol in the patient.

Adult↗
PubMed1991

Insulin-like growth factor-II (IGF-II)/Mannose-6-phosphate receptors are increased in primary human thyroid neoplasms.

Insulin-like growth factor (IGF)-II receptors were demonstrated in normal and neoplastic tissues of human thyroid. Specific binding of [125I]IGF-II to thyroid membranes was dependent on the time and temperature of incubation, and a steady state was achieved after 22 h of incubation at 4 degrees C. The binding of [125I]IGF-II was dose-dependently displaced by unlabelled IGF-II with 50% inhibition at an IGF-II concentration of 6 ng/ml. IGF-I had a relative potency of 1% compared to IGF-II, and insulin showed no inhibition at concentrations as high as 2000 ng/ml. Scatchard analysis of the binding data revealed a single class of IGF-II receptor with high affinity. Affinity crosslinking and autoradiography demonstrated the type II IGF receptors. Specific binding of [125I]IGF-II to thyroid papillary cancer tissues (mean [S.D.]13.2[1.3]% per 200 micrograms protein, n = 8) was significantly (P less than 0.01) higher than that to the surrounding normal tissues (4.8 [0.5]%). The binding in follicular cancer and follicular adenoma was also significantly higher than that in the corresponding normal tissues. The higher IGF-II binding to neoplastic tissues was due to an increase in the number of binding sites without any change of affinity. These results suggest that the increased IGF-II receptors may be involved in growth or functions of thyroid neoplasms.

Binding, Competitive↗
PubMed1991

Prevalence of chondrocalcinosis in patients with primary hyperparathyroidism in Japan.

One hundred and thirty-two consecutive patients with primary hyperparathyroidism were studied preoperatively for the presence of chondrocalcinosis, the roentgenographic marker of calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, by obtaining radiographs of knees, wrists and pelvis. Chondrocalcinosis was found in 8 patients (6.1%), each of whom was over 50 years of age. In 72 of the patients over 50 years of age, the prevalence of chondrocalcinosis in the hyperparathyroid patients (11.1%) was greater than that found in 72 control patients (2.8%) with thyroid nodular disease who were exactly matched for age and sex, but the difference was not significant. The prevalence of chondrocalcinosis in the hyperparathyroid patients sharply increased with age. In the group in their 50's it was 4.4%, rising to 15.8% in patients in their 60's and reaching 37.5% for those over 70 years of age. Patients with chondrocalcinosis were significantly older than those without this finding (p < 0.005). Those with chondrocalcinosis also had significantly higher preoperative serum calcium levels than those without it (p < 0.05). While chondrocalcinosis was detected by taking joint radiographs in all patients with primary hyperparathyroidism, acute arthritis (pseudogout attack) occurred in only 2 of the 132 patients (1.5%) after parathyroidectomy, but this represents 25% (2 of 8) of those who had chondrocalcinosis. An attack of pseudogout may therefore be one of the most common postoperative complications of parathyroid surgery in the elderly. Considering the low incidence of pseudogout attack following parathyroidectomy, preoperative radiological studies of the knee joints are sufficient to screen for chondrocalcinosis and are recommended for patients over 60 years old in Japan.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Mucin-producing tumor of the pancreas: a unique clinical entity.

We report our experience with nine patients with "mucin-producing tumor of the pancreas," in which abundant mucin secreted by the tumor cells played a major role in the characteristic alterations of the pancreatic duct system. Four of nine patients presented with pancreatitis. Ultrasound and computed tomography demonstrated a well-defined cystic mass and dilated main pancreatic duct. Endoscopic retrograde pancreatography showed ductectatic character, i.e., diffuse dilatation of main duct and/or cystic dilatation of the branch ducts with filling defects of mucin. Ultrasound proved to be a good screening test. However, the diagnosis was confirmed on endoscopic retrograde pancreatography. Nine of our cases had no peripancreatic invasion or metastasis, resulting in a good prognosis after pancreatectomy. Mucin-producing tumor of the pancreas is a unique clinical entity that should be distinguished from "common" pancreatic carcinomas, and a favorable prognosis can be expected after surgical operation.

Adenocarcinoma, Mucinous↗
PubMed1991

[Perioperative cardiac complications of pulmonary operations in patients with/without coronary stenosis].

It has been suggested that the presence of ischemic heart disease correlates with an increased risk of cardiac infarction and fatal arrhythmia following noncardiac operations. To prevent these complications, coronary arteriographies were performed on 55 patients before pulmonary surgery for the assessment of the risk of perioperative cardiac complications. A coronary artery obstruction, with a 50% or greater reduction in the internal diameter was recognized on 21 patients (Group 1) and the other 34 patients showed no significant coronary stenotic lesions (Group 2). Discriminant analysis revealed that cardiac index (p less than 0.025), blood sugar level (p less than 0.05), hyperlipidemia (p less than 0.05) and postoperative cardiac failure (p less than 0.005) correlated independently with coronary artery stenosis. Postoperative cardiac complications were observed in the form of atrial arrhythmias (11%), ventricular arrhythmias (16%) and ischemic ECG findings (17%) in all cases. The rate of occurrence of these complications were not different between the two groups. However, the need for therapeutic procedures for perioperative circulatory failure (18%) was much greater in group 1 (p less than 0.005). This study supports the merits of preoperative coronary arterial angiography and the estimation of the left ventricular function in reducing pulmonary perioperative risk.

Aged↗
PubMed1991

[A case of bronchial anastomotic stenosis after right upper sleeve lobectomy treated with silicone stent].

A case treated with silicone stent for bronchial granulomatous stenosis caused by anastomosis after right upper sleeve lobectomy was reported. A 68-year-old man complained of atelectasis of right upper lobe due to squamous cell carcinoma was admitted to our department. We performed right upper sleeve lobectomy. Four weeks after the operation, hemoptysis and dyspnea appeared with developing local empyema. We performed closure of pleural fistula and thoracoplasty, however, did not improve the symptoms. We performed tracheotomy for deteriorating dyspnea. In addition, granulomatous stenosis of bronchial anastomotic site was observed endoscopically. We tried to insert silicone stent into stenotic site. Although, first trial was in failure, we modified the design of the stent and succeeded in fixation of the stent. The airway was completely re-opened and good patency had been maintained for 7 months until his death due to pneumonia.

Aged↗
PubMed1991

[Immunohistochemical study on the expression of epidermal growth factor receptor (EGFR) in human colorectal carcinomas].

The expression of epidermal growth factor receptor (EGFR) was studied immunohistochemically in 92 colorectal carcinomas: 21 early and 71 advanced. EGFR immunoreactivity was detected in 15 cases (16.3%) of colorectal carcinomas. All EGFR-positive cases was advanced carcinomas, while no EGFR immunoreactivity was found in early carcinomas. EGFR-positive cases were macroscopically 3.4 type and more than 2 cm in diameter. No significant correlation of EGFR expression with tumor location, stage, lymph node metastasis, degree of differentiation, and prognosis was found. All EGFR-positive cases was synchronous positive for the expression of EGF. These results suggest that EGFR may play an important role in tumor progression in cooperation with EGF.

Adult↗
PubMed1990

Diffuse sclerosing variant of papillary carcinoma of the thyroid. Clinical importance, surgical treatment, and follow-up study.

A diffuse sclerosing variant is not very rare among papillary carcinomas of the thyroid when the patients are female and younger than 30 years of age. The variant is characterized by diffuse involvement of one or both thyroid lobes, with dense sclerosis, patchy lymphocytic infiltration, and abundant psammoma bodies. Controversy still exists concerning its prognosis. We reviewed our experience with 14 patients treated between 1958 and 1988. All patients were young females, their age being from 10 to 28 years with a mean of 19.6. Hashimoto's thyroiditis had been suspected in nine patients before they came to our clinic. Nowadays the diagnosis of this cancer is possible when we have this entity in mind and detect abundant psammoma bodies either by ultrasonography or by soft-tissue roentgenography of the neck. Total thyroidectomy with modified neck dissection was carried out in eight patients, subtotal thyroidectomy with neck dissection in five, and lobectomy with neck dissection in one. All of them are alive and well without distant metastasis at a mean follow-up of 16 years. Because most of the patients with this variant of papillary carcinoma are young women and the prognosis is favorable, a complete resection without causing later recurrence, but also cosmetic and complication-free surgery, should be considered.

Adolescent↗
PubMed1990

Flow cytometric DNA analysis of parathyroid tumors. Implication of aneuploidy for pathologic and biologic classification.

The previous cytometric studies on parathyroid tumors have provided conflicting data regarding the relationship between DNA content and histopathology, resulting from differences in technical methods and data analysis. This study measured nuclear DNA of parathyroid tumors by flow cytometry in fresh material and determined whether DNA aneuploidy really assists in making a pathologic diagnosis of carcinoma or not. From May 1987 through April 1989, 65 consecutive patients operated on for primary hyperparathyroidism had DNA analysis of the freshly excised parathyroid tumors. Three of the patients had metastatic lesions of parathyroid carcinoma in the lung, cervical lymph nodes, and lung and mediastinal lymph nodes, respectively. Pathologic classifications of the lesions from the other 62 patients were 54 adenomas, four carcinomas, and four hyperplasias. In all the latter patients, hyperplasia was associated with a multiple endocrine neoplasia syndrome. Unequivocal evidence of aneuploidy was found in all of the metastatic lesions and 60% of the primary lesions of the carcinomas, in 9% of the adenomas and in 50% of the hyperplasias. Therefore, parathyroid carcinomas were more apt to be aneuploid than were adenomas (P = 0.0015, both-sided testing). In each of the cases of aneuploid hyperplasia, a small aneuploid peak was found. The high incidence of aneuploidy in patients with multiple endocrine neoplasia type 1 may indicate the presence of clonal heterogeneity of hyperplastic glands and the presence of an abnormal subset of cells that have malignant potential. Cell distribution analysis did not provide any significant information beyond ploidy level. In conclusion, DNA flow cytometric analysis of DNA ploidy patterns is a valuable adjunct to the histopathologic diagnosis of parathyroid neoplasms.

Adenoma↗
PubMed1990

Flow cytometric DNA analysis of parathyroid tumors with special reference to its diagnostic and prognostic value in parathyroid carcinoma.

The nuclear DNA content of paraffin-embedded parathyroid tumors from 49 patients with proven primary hyperparathyroidism was determined by flow cytometric analysis. The lesions included 14 primary and 11 locally recurrent or metastatic lesions from 16 carcinoma patients, 28 single adenomas from 28 patients, and 15 hyperplastic glands from five patients with familial multiple endocrine neoplasia type 1. No abnormal DNA stemline was found in any of the hyperplastic glands. One (3.6%) of the adenomas was aneuploid. There was no difference in ploidy patterns between the primary and recurrent lesions of the carcinomas and five (31%) of the carcinomas expressed aneuploidy. Four of the five patients with aneuploid carcinoma had recurrences including pulmonary metastases. One of them died of this disease 12 years after the initial operation, and all except one of the others are hypercalcemic even after removal of the successive recurrent or metastatic tumors. Of the 11 patients with diploid carcinoma, four had either local recurrence or pulmonary metastasis. Two of them are living with normocalcemia 3 and 6 years, respectively, after removal of the recurrent tumors and the others are alive with mild hypercalcemia. The remaining seven patients with diploid carcinoma, however, have no recurrence 2 to 5 years after the initial operation. Thus aneuploid parathyroid carcinomas are likely to show more malignant behavior than those with a diploid DNA pattern. All of the patients with adenoma and hyperplasia have been normocalcemic after a mean follow-up interval of 37 months. This study indicates that flow cytometric analysis of nuclear DNA content is a valuable adjunct to histologic examination in the diagnosis of parathyroid carcinoma and the prediction of the clinical outcome.

Adenoma↗
PubMed1990

Augmented enkephalin-immunoreactivity in adrenaline-producing phaeochromocytomas.

Immunohistochemical studies for methionine- and leucine-enkephalin were performed on 26 phaeochromocytomas to elucidate the patho-physiological roles of enkephalins. Positive reactions were seen in all phaeochromocytomas with varying intensities. The location of methionine- and leucine-enkephalin agreed fairly well with each other. Stronger immunostaining was obtained in phaeochromocytomas secreting both adrenalin and noradrenaline than in those secreting predominantly noradrenaline. Paroxysmal hypertension was frequently observed in patients with adrenalin-secreting phaeochromocytomas, especially those with marked enkephalin positivity. Urinary excretion of metanephrine was significantly correlated with enkephalin positivity. These findings show that all phaeochromocytomas retain the ability to produce enkephalins of the adreno-medullary or extra-medullary chromaffin tissues from which they derive. Augmented enkephalin-immunoreactivity in adrenalin-producing phaeochromocytomas may be interpreted as reflecting a close association of enkephalins with adrenalin under physiological conditions.

Adrenal Gland Neoplasms↗
PubMed1990

Mid-mediastinal parathyroid lesions: preoperative localization and surgical approach in two cases.

Although hyperfunctioning mediastinal parathyroid lesions that require median sternotomy or thoracotomy for removal are occasionally present, the majority are located in the anterior mediastinum closely associated with the thymus. Only eight cases of ectopic hyperfunctioning parathyroid tumors in the middle mediastinum have been reported. We experienced two cases of either persistent or recurrent hyperparathyroidism in which abnormal parathyroid tissue was located in the aorticopulmonary window. One of the patients had a parathyroid adenoma and the other had metastatic lesions of parathyroid carcinoma. In both cases, thallium scanning proved useful in identifying the lesions while computed tomography scan was effective for mediastinal three-dimensional localization. In one case, single photon emission computed tomography imaging with thallium proved beneficial for both identification and localization of the middle mediastinal lesion. The surgical approach used in both cases was different. In one case, left thoracotomy was performed, after which the ligamentum arteriosum was divided, and an adenoma anterior to the left main bronchus and posterior to the left pulmonary artery removed. In the other case, two metastatic tumors of parathyroid carcinoma anterior to the right main bronchus and posterior to the right pulmonary artery were resected through a median sternotomy and opening of the pericardium.

Adenoma↗
PubMed1990

Stromal fat content of the parathyroid gland.

The proportion of stromal fat cells to parenchymal cells in 100 normal parathyroid glands was determined by the image analyzing computer technique. The parathyroid glands were resected at the time of thyroidectomy in 86 patients with thyroid tumors. None of the patients had any evidence of parathyroid dysfunction preoperatively. In the histologic sections of the parathyroid glands, the average percentage of stromal fat cell content was 38%. The percentage of stromal fat cells was correlated with the age and the body constitution of the patients, but the percentages of fat cells varied widely among glands in the given age and body constitution ranges. It was therefore not possible to discriminate a normal parathyroid gland from an abnormal gland solely on the basis of microscopic determination of stromal fat cell content.

Adipose Tissue↗