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Biomedical subjects

F Kitamura

Publications and source records attributed to F Kitamura.

At least 55 records · Page 3Linked to original sources
PubMed1992

Reconstitution of the intermediate-affinity interleukin-2 receptor by cell fusion.

Although IL-2 receptor beta chain (IL-2R beta) expressed in various lymphoid cell lines binds IL-2 with an intermediate affinity, IL-2R beta expressed in fibroblasts is unable to bind IL-2, suggesting that IL-2R beta is on its own not sufficient for generating the intermediate-affinity receptor and that lymphoid-specific regulatory control may be operated to allow IL-2R beta to bind IL-2. In the present study, we observed that human IL-2R beta expressed in a mouse myeloma X63-Ag8.653 (X63) by cDNA transfection did not bind IL-2, while the same IL-2R beta expressed in an IL-6-dependent mouse B cell hybridoma F12-28, which was obtained by cell fusion between X63 and lipopolysaccharide (LPS)-induced lymphoblasts, bound IL-2 with the intermediate affinity. Interestingly, when the human IL-2R beta cDNA-transfected X63 clone, which by itself manifests no IL-2 binding, was fused with LPS-induced lymphoblasts, the resultant hybridomas manifested intermediate-affinity IL-2 binding. The IL-2 binding was specifically inhibited by addition of antihuman IL-2R beta mAb (Mik-beta 1) but not by mAb against mouse IL-2R subunits, indicating that human IL-2R beta was responsible for the IL-2 binding, i.e. non-functional human IL-2R beta in X63 was converted to competent IL-2R beta by complementation with a mouse spleen cell-derived factor(s) through the cell fusion. Cross-linking experiments with [125I]IL-2 revealed the presence of a 61 kDa protein other than IL-2R beta in cells expressing the intermediate-affinity IL-2R.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

In utero treatment with monoclonal antibody to IL-2 receptor beta-chain completely abrogates development of Thy-1+ dendritic epidermal cells.

Interleukin-2 (IL-2), a crucial growth factor for mature T lymphocytes, is produced in fetal thymus under developmental control, although its biological significance remains unclear. We found that the two distinct subunits of the IL-2 receptor, i.e. the alpha-chain (IL-2R alpha) and the beta-chain (IL-2R beta), were expressed in an almost mutually exclusive fashion throughout fetal thymus ontogeny, and that the blockade of IL-2R beta, a signal transducing component of IL-2R, by administering a neutralizing mAb to IL-2R beta resulted in the complete and selective disappearance of Thy-1+ skin dendritic epidermal cells. Development of any other T cell subsets was uncompromised. This indicates that IL-2 plays a crucial role in the development of fetal V gamma 5+ cells and their descendants.

Animals↗
PubMed1992

[A case of large cell carcinoma of the lung which is suspected of producing granulocyte colony-stimulating factor].

A 41-year-old male complaining of fever and left shoulder pain was admitted to our hospital for further examination of an abnormal shadow on chest X-ray film. His laboratory data on admission showed marked leukocytosis and elevation of serum alkaline phosphatase. The diagnosis of large cell carcinoma of the lung was made by percutaneous biopsy and he was staged clinically as T3N0M0. Chemotherapy including CDDP and VDS resulted in resolution of symptoms and normal laboratory data. After three courses of chemotherapy, he underwent left upper lobectomy with chest wall resection. Pathological diagnosis of the resected tumor was large cell carcinoma with giant cells, and he was staged postoperatively as T3N0M0. Since colony stimulating activity was demonstrated in both homogenate of tumor cells and tumor conditioned medium, and preoperative serum granulocyte colony-stimulating factor (G-CSF) was 105 pg/ml, we concluded that leukocytosis in this patient was caused by G-CSF produced by tumor cells. The patient was in good health two years after surgery with no signs of recurrence.

Adult↗
PubMed1992

[The right to treatment of the institutionalized mentally ill in the United States].

In his epochmaking article, Birnbaum proposed that courts should recognize a right to treatment of institutionalized psychiatric patients based on the substantive due process. His proposal was adopted in Rouse v. Cameron as a statutory right. Wyatt v. Stickney decision was the first to hold that there was a constitutionally based right to treatment for involuntarily committed patients. The Supreme Court, though reluctantly, held in Youngberg v. Romeo that the institutionalized mentally retarded were entitled to minimally adequate training, which was drawn in the Fourteenth Amendment.

Commitment of Persons with Psychiatric Disorders↗
PubMed1991

A novel monoclonal antibody against murine IL-2 receptor beta-chain. Characterization of receptor expression in normal lymphoid cells and EL-4 cells.

A mAb specific for the murine IL-2R beta-chain (IL-2R beta) was produced by immunizing a rat with a rat transfectant cell line expressing a large number of cDNA-encoded murine IL-2R beta. The mAb, designated TM-beta 1, is specifically reactive with the murine IL-2R beta cDNA-transfectant but not with the recipient cell, and immunoprecipitates murine IL-2R beta of Mr 75 to 85 kDa. TM-beta 1 mAb completely abolished the high affinity IL-2 binding by inhibiting the ligand binding to IL-2R beta. Murine IL-2R beta was found to be constitutively expressed on a subpopulation of CD8+ T cells and almost all NK1.1+ NK cells in the spleen, whereas TM-beta 1 mAb inhibited the proliferation of spleen cells induced by 1 nM of IL-2. Interestingly, EL-4 cells that express murine IL-2R beta as detected by TM-beta 1 mAb can bind neither human nor murine IL-2 under the intermediate affinity conditions, although cDNA-directed human IL-2R beta expressed in the same EL-4 cells has been previously shown to manifest the intermediate affinity IL-2 binding. These results may imply that functional expression of IL-2R beta is differentially regulated between humans and mice. Finally, our neutralizing anti-IL-2R beta mAb TM-beta 1 will be useful not only for various in vitro studies but also for in vivo studies to directly investigate the possible involvement of the IL-2/IL-2R pathway in the generation and differentiation of T lymphocytes and NK cells.

Animals↗
PubMed1991

[Squamous cell carcinoma of the thymus].

A 68-year-old woman was admitted with cough and dyspnea. Her chest X-ray showed right pleural effusion and a mediastinal tumor. She underwent mediastinotomy following a preoperative diagnosis of invasive thymoma. A tumor originating from the thymus had invaded the right middle lobe and pericardium, and multiple pleural dissemination was also found. Therefore, considering the patient's age and pulmonary function, we performed only subtotal resection of the tumor. The pathological diagnosis was poorly differentiated squamous cell carcinoma. The patient received irradiation and chemotherapy including Cisplatin after surgery, but she died 1 year later because of rapid progression of distant metastases.

Aged↗
PubMed1990

The IL-2 receptor beta-chain (p70). Ligand binding ability of the cDNA-encoding membrane and secreted forms.

The high affinity IL-2R is composed of at least two distinct subunits; alpha (p55 or Tac)- and beta (p70)-chains. Recent cDNA expression studies with lymphoid cells unequivocally demonstrated that the IL-2R beta is an indispensable component for the ligand internalization and the signal transduction via the high affinity IL-2R. Furthermore, these studies confirmed that the IL-2R beta singly expressed on T lymphoid cells represents the intermediate affinity IL-2R. In the present study, however, we show 1) the IL-2R beta expressed on a mouse fibroblast line, NIH-3T3, did not bind IL-2 under the intermediate affinity conditions, 2) nevertheless, the IL-2R beta coexpressed with the IL-2R alpha not only formed the high affinity receptor but also internalized IL-2. By the use of competitive sandwich ELISA to study the IL-2 binding ability of the IL-2R beta molecule itself, we also show that the IL-2R beta present in the detergent-solubilized cell extracts and the secreted IL-2R beta (p37) produced by the truncated cDNA are actually capable of binding IL-2, but with a much reduced affinity compared with the intact IL-2R beta expressed on the lymphoid cells. These findings lead us to postulate a more complex feature of the IL-2R than ever speculated; the IL-2R beta molecule having on its own minimal IL-2 binding ability requires a putative gamma-chain specifically present on lymphoid cells to generate the functional intermediate affinity IL-2R. The gamma-chain, however, seems not to be required as far as the formation of the high affinity IL-2R by the alpha- and beta-chains and the ligand internalization through it are concerned.

Amino Acid Sequence↗
PubMed1990

Field dependence and body balance.

This study reports four points about the portable Rod and Frame Test performance of 30 Japanese women in terms of body balance. The primary findings using a stabilometer are: (a) field dependence correlated negatively with increased sway path within 1 min. both while a dot pattern as a visual stimulus was stationary and while it was moving. (b) Field dependence correlated positively with the difference in sway path between the two following phases, in one of which the subjects watched the horizontal visual movement to the right and in the other movement to the left. (c) Motion aftereffect had no direct and immediate influence on sway path, but rather a latent and long-term effect. And on a pedograph which measures the distribution of foot pressure and the shape of the sole, (d) field dependence correlated negatively with anterior positions of the center of foot pressure and with the proportion of the front part to the rear of the sole. Over-all, field dependence measured by the Rod and Frame Test seems to be associated with body posture when dot patterns are viewed.

Adult↗
PubMed1990

[Results of surgery in non-small cell lung cancer].

Two hundred and nine patients with non-small cell lung cancer underwent surgical treatment from January, 1978 to December, 1987 at the Kochi Municipal Hospital. There were 126 men and 83 women, varying in age from 36 to 85 years. The post-surgical stage distribution was as follows: 121 patients with Stage I, 22 with Stage II, 43 with Stage IIIA, 14 with Stage IIIB and 9 with Stage IV. The 5 year survival rate was 54% for all patients and only 3 patients of them (1.4%) died within the first month following operation. The 5 year survival rate was 71% for Stage I, 22% for Stage II, 38% for Stage IIIA, 36% for Stage IIIB and 25% for Stage IV. The 5 year survival rate was 66% for absolutely curative operation, 46% for relatively curative operation, 55% for relatively noncurative operation and 19% for absolutely noncurative operation. This series have 41 patients (19.6%) over 70 years old, and the 3 year and the 5 year survival rates for this high age group were 58% and 40%, respectively. Statistically, there was no significant difference in survival rate between this high age group and the younger group. Our successful experiences of the bronchoplastic procedures, extended resections and limited operations were also reported.

Adult↗
PubMed1990

[Analysis of T1N0M0 nonsmall cell lung cancer undergoing surgical resection without mediastinal lymph node dissection].

Eleven patients of T1N0M0 non-small cell lung cancer underwent relatively non-curative surgical resection without mediastinal lymph node dissection (the undissected group). The 5 year survival rate of this group was 70.7% and no significant difference in survival was found between the undissected group and the patients of T1N0M0 non-small cell lung cancer undergoing absolutely curative surgical resection (the dissected group). No patient died of pneumonia in the undissected group, while 4 aged patients in the dissected group died of pneumonia. This may suggest that mediastinal lymph node dissection is also injurious in distant period after surgery, especially in the aged patient. So "simple lobectomy" without mediastinal lymph node dissection may be considered as an elective procedure in the poor risk patient such as the aged, who has an early staged non-small cell lung cancer.

Adult↗
PubMed1990

Schizophrenia, eye movements, and biocultural heterogeneity.

Smooth-pursuit eye-tracking dysfunction is a putative genetic trait marker for schizophrenia. In this study 88 Japanese schizophrenics from Kyushu and Okinawa were examined for the marker using precise high-resolution instrumentation: 76% of the schizophrenics from Kyushu and 89% of those from Okinawa had pursuit dysfunction. The presence of the culture-neutral smooth-pursuit marker for schizophrenia in Japan demonstrates that the etic concept "schizophrenia" is cross-culturally valid. Furthermore, the ubiquity of the marker in biologically and culturally diverse populations may indicate a limit on the extent of meaningful heterogeneity likely to be discovered within the condition.

Adult↗
PubMed1989

Reconstitution of a functional IL-2 receptor by the beta-chain cDNA. A newly acquired receptor transduces negative signal.

The high-affinity IL-2R results from the noncovalent association between at least two subunits; alpha (p55) and beta (p70), both of which are capable of binding IL-2 with a low and intermediate affinity, respectively. Although the alpha-chain itself has been shown to be nonfunctional, suggestions have been made that the beta-chain mediates an IL-2 signal. To directly study the role of the beta-chain in the signal transduction, we transfected with the cDNA encoding the IL-2R beta-chain a human T lymphotropic virus-I-transformed T cell line, MT-1 originally expressing low-affinity alpha-chain alone, and established a stable transformant (designated MT-beta 7) which expressed both alpha- and beta-chains simultaneously. We showed 1) MT-beta 7 manifested the high-affinity IL-2 binding, which was completely disrupted by the anti-beta chain mAb (Mik-beta 1), 2) the 125I-IL-2 crosslinking patterns of MT-beta 7 were indistinguishable from those of cells expressing the native high-affinity IL-2R, 3) MT-beta 7, but not parental MT-1, internalized the bound IL-2 and responded to IL-2 with a negative signal, i.e., inhibition of the de novo DNA synthesis. These results clearly demonstrate that the beta-chain not only participates in forming the high-affinity IL-2R with the alpha-chain but also is directly involved in the IL-2 signal transduction.

Cell Line↗
PubMed1989

Characterization of the interleukin 2 receptor beta chain using three distinct monoclonal antibodies.

The human high-affinity receptor for interleukin 2 (IL-2) has been proposed as being a membrane complex composed of at least two distinct polypeptide chains: p55 (alpha chain), recognized by the anti-Tac monoclonal antibody (mAb), and p75 (beta chain), both of which are capable of binding IL-2. Whereas the alpha chain itself has been shown to be nonfunctional, the beta chain appears to be pivotal in the IL-2 signal transduction, although the beta chain is otherwise poorly characterized. Three beta chain-specific mAbs, designated Mik-beta 1, -beta 2, and -beta 3, were developed. Mik-beta 1 and -beta 2 completely inhibited the IL-2 binding to the beta chain, whereas Mik-beta 3 immunoprecipitated the beta chain crosslinked with 125I-labeled IL-2. The beta chain immunoprecipitated by these mAbs was revealed to have a Mr of 68,000-72,000. High-affinity IL-2 binding was completely abolished by Mik-beta 1. Although IL-2-dependent T-cell growth at high IL-2 concentrations was not inhibited by the anti-Tac, it was almost completely inhibited by Mik-beta 1 in the presence of the anti-Tac. These results clearly indicate that the beta chain is an indispensable component to the high-affinity IL-2 receptor and is responsible for the IL-2 signal transduction. The beta chain was found to be constitutively expressed without the alpha chain on the surface of peripheral blood Leu-19+ natural killer cells.

Animals↗
PubMed1988

Molecular mechanisms underlying lymphocyte recirculation. I. Functional, phenotypical and morphological characterization of high endothelial cells cultured in vitro.

Large-scale extravasation of lymphocytes takes place in vivo under physiological conditions in lymph nodes at very specialized vascular segments called high endothelial venules (HEV). When circulating lymphocytes leave the blood, they first bind to endothelial cells of HEV (HE cells) and subsequently enter lymph nodes by crossing the endothelial lining of HEV. Although the lymphocyte-HEV interaction has recently been the subject of intense research by many laboratories, it has been studied almost exclusively by the use of the lymphocyte-binding assay in which lymphocyte binding is examined on nonviable HEV present on frozen sections and, hence, no dynamic interaction between HE cells and lymphocytes has been studied. We report herein that endothelial cells of rat HEV can be grown in vitro and that the lymphocyte-HEV interaction can be studied dynamically using viable cells in culture vessels. The identification of the cultured line, termed Ax, as HE cells was based on their phenotypic, morphological, cytochemical and biochemical characteristics, and most importantly on its in vitro behavior, particularly in terms of its specific ability to interact with mature lymphocytes. Phenotypic analysis demonstrated that not only did monoclonal antibodies, known to react with HE cells, recognize the Ax but also a monoclonal antibody raised against the Ax specifically recognized HE cells in vivo, as determined by an immunoperoxidase staining of frozen sections, supporting the notion that the cell strain, Ax, is derived from HEV. This Ax, even after long-term culture (greater than 50 passages), allowed mature, but not immature, lymphocytes to bind to the cell surface and subsequently transport bound cells underneath their cytoplasm. This phenomenon was inhibited in a dose-dependent manner by various reagents known to inhibit lymphocyte recirculation in vivo. The cultured line derived from HE cells should provide a means to investigate the biochemical nature of lymphocyte-HEV interaction, and to understand the molecular mechanisms underlying the large-scale lymphocyte traffic taking place in vivo.

Animals↗
PubMed1987

Studies on the hemolytic activity of the classical and alternative pathway of complement in various animal species.

The classical complement pathway (CP) activity (CH50) of sera of 13 animal species was compared by parallel assays using rabbit erythrocytes sensitized with immune antibody (RaE-Ab) and sensitized sheep erythrocytes (ShE-Ab). The alternative complement pathway (AP) activity (ACH50) in various species of animals was also measured using 13 species of erythrocytes and RaE-Ab as target cells. The results have demonstrated that virtually all species of animals studied possess CP and AP activity levels comparable with or higher than those in human sera. Concomitant measurement of the hemagglutinin titer to various species of erythrocytes carried out in the screening ACH50 assays on various species of sera with these erythrocytes disclosed a significant correlation between natural antibody level and AP activity (p less than 0.05).

Animals↗
PubMed1985

A simplified method for the preparation of EAC14 intermediate cells using human serum treated with methylprednisolone.

The inhibitory effect of methylprednisolone 21-succinate ester (MPS) on the activities of complement components in human serum was studied by incubating human serum with various concentrations of MPS at 37 degrees C for 30 min and then measuring the residual activity of each component in human serum. The formation of EAC1 and EAC14 by C1 and C4 respectively, were only weakly inhibited by MPS at a final concentration of 10 mg/ml. In contrast, the same concentration of MPS completely inhibited the capacity of C2, C3, C5 and C6-9 to induce respective succeeding intermediates. On the basis of these findings a simplified method was devised for the preparation of EAC14 intermediates using human serum pretreated with MPS.

Animals↗
PubMed1984

Clinical application of transvenous mitral commissurotomy by a new balloon catheter.

A new balloon catheter was developed which allows mitral commissurotomy without thoracotomy. The procedure has been successful in five of the six patients with mitral stenosis so treated. In the remaining patient, the procedure could not be performed because of technical difficulties. The balloon is reinforced with a nylon micromesh and its shape changes in three stages, depending on the extent of inflation. It is inserted from the saphenous vein into the mitral orifice transseptally, fixed across the mitral orifice with partial inflation, and finally inflated to full its extent, separating the fused commissures by its expansile force. After the procedure, catheterization revealed a significant reduction in the mean diastolic pressure gradient across the mitral valve without resultant mitral regurgitation in each patient. Two-dimensional echocardiograms showed a marked to moderate degree of dilatation of the mitral orifice in each patient. All five patients are well with remarkable clinical improvements 2 to 16 months after the procedure.

Adult↗