Ga-67 and Tc-99m (V) DMSA imaging in non-Hodgkin's lymphoma with amyloid tumor

This report describes the localization and categorization of tumors using Ga-67 and Tc-99m (V) DMSA imaging in a rare case of non-Hodgkin's lymphoma associated with an amyloid tumor. Ga-67 uptake was found in both the lymphoma and the amyloid tumor. Significant Tc-99m (V) DMSA uptake was found only in the amyloid tumor. In this case, Ga-67 uptake was nonspecific, but Tc-99m (V) DMSA uptake gave additional information before treatment.

Rearrangement of esophageal-carcinoma cells and stromal fibroblasts in a multicellular spheroid

Using a thermo-responsive polymer, a collagen-conjugated poly-N-isopropyl acrylamide (PNIPAAm) as a substratum, we developed hetero-multicellular spheroids (MCS) composed of esophageal squamous carcinoma cells (TE10) and esophageal fibroblasts isolated from esophageal carcinoma tissue. PNIPAAm is insoluble in water above the lower critical solution temperature (LCST; about 32 degrees C) and becomes reversibly solubilized below the LCST. Taking advantage of this conversion, we prepared three types of hetero-MCS as follows: F/T-multicellular spheroids made by seeding of TE10 onto a preprepared monolayer of fibroblasts; T/F-multicellular spheroids made by seeding of fibroblasts onto a preprepared monolayer of TE10; Mixed-multicellular spheroid made from a monolayer of mixed fibroblasts and TE10. Histolo,oical and immunohistochemical examinations revealed that fibroblasts and TE10 cells were intermingled in 5-day-old multicellular spheroids but were divided into three zones in 1- or 2 week-cultured spheroids: into an external zone composed almost entirely of TE10 cells that were positive for epithelial membrane antigen (EMA), an intermediate zone composed of fibroblasts that were positive for vimentin, and a necrotic zone showing variable evidence of cell injury. This distribution was observed in all three types of the spheroids described above. These findings indicate that TE10 cells are able to migrate and cover the surface to make organizing spheroid, thus mimicking in vivo structures. We conclude that the three-dimensional culture system using a thermo-responsive polymer, which enables coculturing with different types of cells as a heteromilticellular spheroid, is a useful model to examine the interaction between carcinoma cells and their stroma cells as it occurs in vivo.

Establishment and characterization of immortalized human coronary endothelial cells

We established an immortalized cell line from endothelial cells derived from a human coronary artery, isolated at autopsy from 76-year-old male, by transfecting the cells with origin-minus simian virus 40 DNA. These cells showed SV40 T antigen in the nuclei and Ulex europaeus I agglutinin and factor VIII-related antigen, as endothelial cell markers, in their cytoplasm. This cell line synthesized prostacyclin, tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) as well as produced the proform of matrix metalloproteinase 1, which was activated by cultivating the cells with plasminogen. These findings reveal that this immortalized endothelial cell line retains characteristics of human coronary endothelial cells, indicating that this cell line is useful for studying atherogenesis of the coronary artery.

[Successful adjuvant therapy of M-CSF with chemotherapy of two cases of chemotherapy resistant acute promyelocytic leukemia]

We demonstrate two conventional chemotherapy-resistant cases of acute promyelocytic leukemia (APL) who were successfully treated with macrophage-colony stimulating factor (M-CSF). Case no 1 was a 40-year-old woman who was made diagnosis of APL on June, 1992, and treated repeatedly with a conventional chemotherapy, BHAC-DMP regimen, resulting in complete remission on October, 1992. After a couple of years, she had relapse with marked growth of APL cells in bone marrow. She was treated with BHAC-AMP and modified B-triple V but could not obtain remission. Case no 2 was a 36-year-old-man with APL who was treated with BHAC-DMP and BHAC-AMP and modified B-triple V therapy. These three conventional chemotherapy regimen were not effective for him. Eight million units of human native M-CSF was administered intravenously for 14 days after the last BHAC-AMP therapy in case no 1, and for 5 days after the last modified B-triple V therapy in case no 2. After the therapy, APL cells in peripheral blood or bone marrow of both patients disappeared completely and normal hemopoietic cells increased, obtaining in complete remission in both cases. These successful cases treated with M-CSF combining chemotherapy may suggest a new therapeutic strategy for APL in addition to all-trans retinoic acid.

Expression of the histamine H1 receptor gene in relation to atherosclerosis

Histamine in serum and arterial tissue contributes to the pathogenesis of atherosclerosis and the formation of coronary artery vasospasm. As the effect of histamine at a given site will be mediated by its specific receptors, we investigated by in situ hybridization and Northern blot analysis the expression and localization of human histamine H1 receptor mRNA in the arterial wall and in cultured human aortic intimal smooth muscle cells (SMC) and immortalized SMC (ISS10) and endothelial cells (SE1). In situ hybridization showed that SMC and endothelial cells expressed H1 receptor mRNA in vivo and that the expression was increased in SMC in the thickened intima of atherosclerotic foci in both the aorta and coronary artery. By Northern blot analysis, we also detected histamine H1 receptor mRNA in cultured SMC, ISS10, and SE1 and found that platelet-derived growth factor stimulated SMC to increase their expression of the mRNA in vitro. These results suggest that up-regulation of histamine H1 receptor expression by platelet-derived growth factor plays an important role in the initiation and progression of cardiovascular diseases.

Ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules

A rare case of ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules is reported. Macroscopically, nodular or granular lesions were scattered over the inner surface of a huge, multilocular tumor in the left ovary. The histopathological features were consistent with those of previously documented cases, except significant squamous metaplasia in the present case. The pleomorphic sarcoma-like cells showed a positive reaction for vimentin and alpha-antichymotrypsin but were negative for carcinoembryonic antigen and common epithelial membrane antigen by immunohistochemistry. Electron microscopically, the tumor cells had neither desmosomes nor secretory granules, but they possessed abundant intermediate filaments. Both immunostaining and ultrastructure suggested that the sarcoma-like nodules were derived from reactive proliferation of fibrohistiocytic cells. The fibrohistiocytic reaction seemed to occur in response to hemorrhage, because hemorrhage was reported to be associated with the mural nodules in most of the previous cases as well as ours.

Ambient pressure stimulates immortalized human aortic endothelial cells to increase DNA synthesis and matrix metalloproteinase 1 (tissue collagenase) production

In the present study, we investigated the effect of ambient pressure on [3H]-thymidine incorporation and on the production of matrix metalloproteinase 1 (tissue collagenase/proMMP-1) using human aortic endothelial cells immortalized with simian virus 40 (SE-1). Incubation of cells at ambient pressures of 50 and 100 mmHg for 24 h slightly increased [3H]-thymidine incorporation when directly compared with normal culture conditions. The amount of [3H]-thymidine incorporated in SE-1 reached a maximum at 150 mmHg, while a further increase in pressure to 200 mmHg decreased incorporation. The same ambient pressure slightly stimulated human aortic intimal smooth muscle cells (SMC) to increase [3H]-thymidine incorporation but not medial SMC. Immunoblot analysis also showed that ambient pressure, ranging from 50 to 200 mmHg, like 12-O-tetradecanoyl-phorbol-13-acetate stimulated SE-1 to produce proMMP-1, an effect not seen with either intimal or medial SMC. The amount of proMMP-1 produced also reached a maximum level at 150 mmHg. We postulate that human endothelial cells are ambient pressure sensitive and that relatively lower ambient pressures play an important role in the growth of endothelial cells, while higher pressures injure endothelial cells, resulting in the initiation of atherosclerosis. This cell line may prove useful in the investigation of both the physiological and pathological roles of blood pressure on endothelial cell function.

CD8-positive adult T-cell leukemia cells with an integrated defective HTLV-I genome show a paracrine growth to IL-2

We describe a 50-year-old man with adult T-cell leukemia complicated by laryngeal tuberculosis whose tumor cells proliferate in response to IL-2 in a paracrine manner. On admission, the patient's white blood cell count was 17,900/mm3; 73% were abnormal lymphocytes with convoluted nuclei. FACS analysis showed that the tumor cells were CD4-negative, CD8-positive T cells. Southern blot analysis of tumor cells revealed integration of a defective HTLV-I genome lacking gag and pol genes. He was diagnosed with chronic ATL complicated by laryngeal tuberculosis. The primary leukemic cells expressed IL-2R alpha and IL-2R beta detected by FACS and Northern blot analysis and showed marked growth in response to exogenously added recombinant IL-2 in short-term cultures. Northern blot analysis did not show any IL-2 mRNA. We have previously demonstrated that primary leukemic cells from some ATL patients grow in response to IL-2 in an autocrine or paracrine manner. These results suggest that in CD8 ATL, IL-2 may be involved in a paracrine manner.

Reversible complete atrioventricular block due to malignant lymphoma

An 83-year-old man was hospitalized due to general fatigue and dyspnoea. He was diagnosed as having complete atrioventricular (AV) block due to cardiac involvement by a malignant lymphoma. Eleven days after the initiation of chemotherapy, the complete AV block disappeared and only a first degree AV block remained.

[Non-Hodgkin's lymphoma; initially presenting cardiac symptoms]

Two long surviving cases of cardiac lymphoma are reported. The first case was an 83-year old man with complete A-V block, congestive heart failure, and pleural effusion. Echocardiography revealed a widespread tumor from the right ventricular wall to the inner space. Cytological examination of pleural effusion showed B-cell type lymphoma. He was treated with systemic chemotherapy and achieved partial remission, continuing for more than 12 months. The second case was a 50-year old man with superior vena cava syndrome caused by a cardiac tumor occupying the whole right atrium. He was treated with partial resection of the tumor and pathological examination showed B-cell type lymphoma. Then he was treated with systemic chemotherapy for massively residual lymphoma, and achieved partial remission, continuing for more than 20 months. Both cases are in good condition under maintenance chemotherapy. In general, malignant lymphoma which is initially presenting cardiac symptoms (so called "cardiac lymphoma") is not so frequent to diagnose premortally, and its prognosis is poor because of delay of diagnosis due to the location of tumor. In addition, insufficient chemotherapy to avoid cardiac rupture or embolism of the pulmonary artery also tend to make the prognosis poor. Recently, several successful cases of cardiac lymphoma treated with systemic chemotherapy have been reported owing to the progress an diagnostic techniques, including echocardiography, CT scan, Ca-scintigraphy and MR imaging. Our experience also indicated that early diagnosis and intensive systemic chemotherapy can obtain long survival in cases of cardiac lymphoma.

[Clinical characteristics of impacted bile duct stone in the elderly]

Acute cholangitis due to impacted bile duct stone is sometimes fatal and require prompt bile duct decompression. Particularly, AOSC (acute obstructive suppurative cholangitis) is the most serious form of bacterial cholangitis and its prognosis is usually very poor when treated conservatively. We have been treated impacted bile duct stones by decompressing the duct endoscopically. Here, we report the characteristics of our elderly patients with impacted bile duct stones who received urgent decompression treatment mainly by endoscopic techniques. In the endoscopical treatment group, the number of patients with AOSC was 5 out of 46 AC (acute cholangitis) patients (11%) under 69 years old, 14 out of 52 (27%) from 70 to 79 years old, and 12 out of 28 (43%) over 80 years old. Obviously, the severity of acute cholangitis (ratio of AOSC to AC) was higher in the elderly. This tendency was similar to the patients who received urgent transhepatic decompression treatment, although they were small in number. In all the patients treated, 7 were classified into the most serious AOSC category with Reynolds' sign, and notably 6 out of 7 were over 70 years old. More strikingly, 5 of 7 patients were over 80, and their mortality rate was indeed high. Thus, in the elderly, bacterial cholangitis by impacted bile stones was a very serious condition. Especially, the outcome of AOSC over 80 years old with Reynolds' sign was very poor, in spite of emergency endoscopic treatment.

Homologous desensitization of histamine H2 receptors in the human gastric carcinoma cell line MKN-45

The poorly differentiated human gastric carcinoma cell line MKN-45 possesses histamine H2 receptors, which are linked to stimulation of adenosine 3',5'-cyclic monophosphate (cAMP) production. Pretreatment of MKN-45 cells with histamine elicited a rapid and dose-dependent inhibition of cAMP production in response to subsequent administration of histamine, whereas pretreatment with prostaglandin E2 (PGE2) or forskolin, both of which stimulate cAMP formation in these cells, had no effect on the histamine-induced cAMP production. Neither NaF- nor forskolin-induced cAMP production was affected by histamine pretreatment. Scatchard analysis of data obtained for [3H]-tiotidine binding showed that histamine pretreatment affected neither the number of histamine H2 receptors nor the binding affinity of the ligand for the receptors. Finally, histamine pretreatment had no effect on cAMP response to subsequent addition of PGE2, which was reduced by PGE2 pretreatment. These results suggest that histamine induces homologous desensitization of H2 receptors on MKN-45 cells by a mechanism that does not involve stimulation of cAMP production.

Identification, cloning, and characterization of a novel human T-cell-specific tyrosine kinase located at the hematopoietin complex on chromosome 5q

Signal transduction through the T-cell receptor and cytokine receptors on the surface of T lymphocytes occurs largely via tyrosine phosphorylation of intracellular substrates. Because neither the T-cell receptor nor cytokine receptors contain intrinsic kinase domains, signal transduction is thought to occur via association of these receptors with intracellular protein tyrosine kinases. Although several members of the SRC and SYK families of tyrosine kinases have been implicated in signal transduction in lymphocytes, it seems likely that additional tyrosine kinases involved in signal transduction remain to be identified. To identify unique T-cell tyrosine kinases, we used polymerase chain reaction-based cloning with degenerate oligonucleotides directed at highly conserved motifs of tyrosine kinase domains. We have cloned the complete cDNA for a unique human tyrosine kinase that is expressed mainly in T lymphocytes (EMT) and natural killer (NK) cells. The cDNA of EMT predicts an open reading frame of 1866 bp encoding a protein with a predicted size of 72 Kd, which is in keeping with its size on Western blotting. A single 6.2-kb EMT mRNA and 72-Kd protein were detected in T lymphocytes and NK-like cell lines, but were not detected in other cell lineages. EMT contains both SH2 and SH3 domains, as do many other intracellular kinases. EMT does not contain the N-terminal myristylation site or the negative regulatory tyrosine phosphorylation site in its carboxyterminus that are found in the SRC family of tyrosine kinases. EMT is related to the B-cell progenitor kinase (BPK), which has recently been implicated in X-linked hypogammaglobulinemia, to the TECI mammalian kinase, which has been implicated in liver neoplasia, to the more widely expressed TECII mammalian kinase, and to the Drosophila melanogaster Dsrc28 kinase. Sequence comparison suggests that EMT is likely the human homologue of a recently identified murine interleukin-2 (IL-2)-inducible T cell kinase (ITK). However, unlike ITK, EMT message and protein levels do not vary markedly on stimulation of human IL-2-responsive T cells with IL-2. Taken together, it seems that EMT is a member of a new family of intracellular kinases that includes BPK, TECI, and TECII. EMT was localized to chromosome 5q31-32, a region that contains the genes for several growth factors and receptors as well as early activation genes, particularly those involved in the hematopoietic system. Furthermore, the 5q31-32 region is implicated in the genesis of the 5q- syndrome associated with myelodysplasia and development of leukemia.(ABSTRACT TRUNCATED AT 400 WORDS)

Functional characterization of a human brain cholecystokinin-B receptor. A trophic effect of cholecystokinin and gastrin

We have cloned a human brain cholecystokinin (CCK)-B receptor cDNA and characterized its function by introducing it into Chinese hamster ovary (CHO) cells. The deduced amino acid sequence was highly conserved as compared with those of the gastrin receptors in Mastomys enterochromaffin-like cells (90%) and canine parietal cells (89%). Human brain CCK-B receptors possessed slightly but significantly higher affinities for CCK-8 than for gastrin I, while both ligands bound equally to Mastomys enterochromaffin-like cell-derived gastrin receptors. Both CCK-8 and gastrin I markedly augmented phosphoinositide hydrolysis and cytosolic free calcium levels in the CHO transfectants, indicating that the cloned CCK-B receptor could functionally couple with intracellular signaling molecules. Moreover, CCK-8 and gastrin I dose-dependently increased [3H]thymidine incorporation of the CHO transfectants in serum-free medium and promoted cell growth. The CCK-B receptor mRNA was abundantly expressed in particular areas of the human brain and stomach, such as the cerebral cortex and mucosa of the gastric fundus. This is the first demonstration of trophic effects of CCK and gastrin through the normal human brain CCK-B receptor. The availability of this receptor cDNA will help to clarify the precise role of CCK in the central nervous system as well as digestive organs.

Lipofibromatous hamartoma of nerve in the foot

A case of lipofibromatous hamartoma in the foot is described. This tumor-like lesion commonly occurs in the hands, wrists and forearms of young persons. The median nerve is affected in the great majority of cases. Only very rarely, however, is it found in the nerves of the foot. It is believed that the present study is the seventh reported case of lipofibromatous hamartoma in the foot, and is the first case reported in Japan. A review shall be made of the six reported cases in the foot.

[Ph1 positive myeloblastic crisis followed by Ph1 negative, bcr rearrangement positive T lymphoid crisis in a CML case]

A 26 year old Japanese male who had a history of leukocytosis in 1985 and received chemotherapy because of myeloblastic crisis of chronic myelogenous leukemia (CML) from May 1986, was admitted in November 1987. He had lymphadenopathy, lymphoid tumor of paranasal sinus and pleural effusion with marked lymphoid cells infiltration. On admission, laboratory data of peripheral blood and bone marrow revealed remission; lymphoid cells of pleural effusion were positive for CD3, CD4 and CD8. Second induction chemotherapy was performed successfully. After a few months, however, myeloblastic crisis recurred. Intensive chemotherapy ended in failure and he died of renal and heart failure. Chromosome analysis showed Ph1 and additional abnormalities at myeloblastic crisis and normal at T lymphoid crisis, but the same rearrangement of breakpoint cluster region existed in both crisis cells. Therefore we supposed that more than two-step pathogenesis is involved in the development of Ph1 positive or Ph1 negative CML clone of this patient.

Characterization of gastrin/CCK receptors on gastric carcinoid tumor membrane of Mastomys natalensis

Recently, we identified the specific binding site for gastrin on the gastric carcinoid tumor of Mastomys (Praomys) natalensis. In this study, precise characterization of the gastrin binding site on these tumors was performed. Both 125I-human gastrin I (gastrin) and 125I-CCK-8 bound specifically to the cell membrane, and Scatchard analysis revealed a high affinity binding site for each ligand with similar Kd and Bmax values. The specific binding of both 125I-gastrin and 125I-CCK-8 was displaced in a concentration-dependent manner by various related peptides with a relative potency order of CCK-8 > or = gastrin < des(SO3)CCK-8. In addition, L364,718 as well as L365,260 displaced the binding of both ligands with similar potencies. Furthermore, not only gastrin but also CCK-8 increased [Ca2+]i in these tumor cells, the action of both being inhibited by L364,718 as well as by L365,260 (10(-7) M). These results suggest that the carcinoid tumor of Mastomys possesses a high affinity gastrin/CCK binding site coupled to the increase of [Ca2+]i.

Interleukin-2 production by primary adult T cell leukemia tumor cells is macrophage dependent

We have investigated the cellular requirements for IL-2 production by autocrine proliferating tumor cells from four patients with adult T cell leukemia (ATL). Cultures of these ATL cells both produced endogenous IL-2 protein in the absence of added mitogen and proliferated at higher levels when exogenous recombinant IL-2 was added. Depletion of macrophages in the tumor cell cultures resulted in a sharp decline in tumor cell IL-2 production, while re-addition of macrophages reconstituted this response. Macrophage-derived factors including IL-6 and IL-1 also reconstituted IL-2 production in these macrophage depleted cultures. These results raise the possibility that macrophages may play a central role in HTLV-I mediated immortalization of T cells.

Pseudo-high affinity interleukin 2 (IL-2) receptor lacks the third component that is essential for functional IL-2 binding and signaling

Functional studies of the interleukin 2 receptor (IL-2R) of two (ED515-D and Kit225) IL-2-dependent and three (ED515-I, 3T3-alpha beta 11, and Hut102) IL-2-independent cell lines were done. All of these cell lines appeared to express high as well as low affinity IL-2R. However, ED515-I and 3T3-alpha beta 11, which expressed the IL-2R beta chain, did not bind IL-2 at all when IL-2 binding to their IL-2R alpha chain was blocked with anti-Tac monoclonal antibody, whereas the intermediate affinity binding in ED515-D, Kit225, and Hut102 cells remained. We tentatively called the high affinity IL-2R of the former cells pseudo-high affinity IL-2R. The dissociation constant of pseudo-high affinity IL-2R was higher than that of ordinary high affinity IL-2R. Internalization of cell-bound 125I-IL-2 into ED515-I and 3T3-alpha beta 11 cells was less efficient than that into ED515-D cells. The addition of IL-2 neither promoted cell growth nor upregulated IL-2R alpha chain expression in ED515-I and 3T3-alpha beta 11 cells. Furthermore, tyrosine phosphorylation of the cellular proteins (p120, p98, p96, p54, and p38) was induced or enhanced in response to the addition of IL-2 in ED515-D and Kit225 cells, but not in the cell lines expressing pseudo-high affinity IL-2R. Finally, 125I-IL-2 crosslinking followed by SDS-PAGE analysis showed an 80-kD band corresponding to p65 + IL-2, in addition to bands corresponding to IL-2R alpha and beta chain + IL-2 in cells bearing ordinary high affinity IL-2R but not in cells with pseudo-high affinity IL-2R. Taken together, we consider that another protein whose molecular mass is approximately 65 kD is functionally important in IL-2 binding and subsequent signal transduction and may be the third component of IL-2R.

Neither the LCK nor the FYN kinases are obligatory for IL-2-mediated signal transduction in HTLV-I-infected human T cells

IL-2 is one of the principal growth factors regulating the proliferation of T lymphocytes. Although two independent IL-2-binding molecules have been molecularly cloned and shown to participate in the formation of a high affinity receptor complex, their primary structures do not suggest a specific mechanism for IL-2 growth signal transduction across the cell membrane. Neither IL-2 receptor subunit contains an intrinsic kinase domain; nevertheless, tyrosine phosphorylation of various intracellular substrates is one of the first biochemical changes observed following activation of the IL-2 receptor (IL-2R). Both serine/threonine and tyrosine kinases can be co-precipitated as part of the IL-2R complex suggesting that the IL-2 signalling may involve the activation of non-covalently associated intracellular kinases. However, controversy exists as to which kinases are involved in IL-2 signal transduction; in particular, which kinase(s) mediates the first or proximal event(s) in the signalling process. Activation of the IL-2R leads to serine and threonine phosphorylation of the SRC tyrosine kinase family member, LCK, and an increase in LCK tyrosine kinase activity. Furthermore, LCK can be co-immunoprecipitated with the beta chain of the IL-2R indicating its association with the receptor complex. IL-2 has also been reported to increase FYN kinase activity and to alter its association with the 85 kDa subunit of phosphatidylinositol-3 kinase thus suggesting a role for FYN in IL-2 signal transduction. However, in this report, we now demonstrate that neither LCK nor FYN are obligatory for IL-2-induced growth of HTLV-I-infected human T cells. Lack of expression of LCK or FYN in the HTLV-I-infected T cell lines was demonstrated by a combination of Northern blotting, polymerase chain reaction, Western blotting, and in vitro kinase activity. Despite the absence of LCK or FYN, IL-2 induced similar patterns of rapid tyrosine phosphorylation. Similar results were observed in cell lines lacking expression of the LYN, FGR, HCK, and LTK tyrosine kinases. Thus, none of these tyrosine kinases alone appears to be required for growth signalling through the IL-2R in the HTLV-I-infected T cell lines analyzed. The findings raise the possibility that an, as yet, unidentified tyrosine kinase is involved. Alternatively, this biological signalling system may exhibit remarkable redundancy whereby several different tyrosine kinases may be capable of associating with the IL-2R complex and mediating intracellular signalling.

Interleukin-2 (IL-2) induces erythroid differentiation and tyrosine phosphorylation in ELM-I-1 cells transfected with a human IL-2 receptor beta chain cDNA

The molecular mechanism of erythroid differentiation has been still ill-defined. In this study, we introduced a human interleukin-2 receptor (IL-2R) beta chain cDNA into ELM-I-1 cells which differentiated into hemoglobin-positive cells in the presence of erythropoietin (Epo), and established the transformant which expressed IL-2R beta chain. In this transformant, we revealed that IL-2 induced erythroid differentiation and the same pattern of tyrosine phosphorylation as Epo. These data suggest that tyrosine phosphorylation is involved in signal transduction pathway of erythroid differentiation. It is also implicated that the Epo and IL-2 receptor system share a common signal transduction pathway.

[The expression of IL-2 receptor subunits on various leukemic cells]

Interleukin-2 receptors are composed of at least two polypeptide chains of alpha (55KD) and beta (75KD). The IL-2R beta chain is an essential component of the functional receptor for signal transduction of IL-2. We previously reported the distribution of IL-2R subunits among peripheral blood mononuclear cells. We here present some data regarding the expression of IL-2R subunits on various hemopoietic malignant cells. Fresh leukemic cells obtained from adult T cell leukemia patients expressed both alpha and beta chains, and leukemic cells derived from some patients with T cell leukemia, B cell leukemia or myeloid leukemia expressed the alpha and/or beta chain of IL-2R. The IL-2R beta chain on these leukemic cells were demonstrated to be functional for cell growth signaling. IL-2R alpha and beta chains should be tumor markers.

Cloning and characterization of gastrin receptor from ECL carcinoid tumor of Mastomys natalensis

We report here the cDNA cloning of a putative gastrin receptor from enterochromaffin-like (ECL) carcinoid tumor of Mastomys natalensis. For this study, we used the polymerase chain reaction technique to amplify transmembrane domain sequences related to rat pancreatic cholecystokinin (CCK)-A receptor from the ECL tumor cDNA library. The amino acid sequence deduced from the cloned cDNA showed 85.7% and 49.0% identity to canine parietal cell gastrin receptor and rat pancreatic CCK-A receptor, respectively. Ligand binding studies using COS-7 cells transfected with the cDNA showed the same binding specificity for gastrin and CCK-8 as the gastrin receptor on the Mastomys carcinoid tumor membrane. Both gastrin and CCK-8 elevated free cytosolic calcium concentration in COS-7 cells expressing the cloned receptor. RNA blot analysis revealed the expression of the gastrin receptor in both Mastomys stomach and brain.

IL-2-induced signal transduction involves the activation of nuclear NF-kappa B expression

Using electrophoretic mobility shift assays and DNA-protein cross-linking techniques, we demonstrate that IL-2 binding to functional forms of the human IL-2R activates nuclear expression of the eukaryotic transcription factor NF-kappa B. These inductive effects of IL-2 were observed in three different cellular systems including human Jurkat T cells stably transfected with IL-2R beta cDNA, mouse pro-B BA/F3 cells stably expressing human IL-2R beta chains either alone or in combination with human or murine IL-2R alpha chains, and purified primary resting human T cells constitutively displaying small numbers of IL-2R beta molecules. IL-2 activation of nuclear NF-kappa B expression is regulated in part at a post-translational level, involving the rapid translocation of both the 50- and 65-kDa subunits of NF-kappa B from the cytoplasm to the nucleus. However, IL-2 induction also produced an increase in mRNA for NF-kappa B p105, indicating an additional pretranslational component of regulation. In contrast, IL-2 exerts only minor effects on NF-kappa B p65 mRNA expression. IL-2 induction of NF-kappa B through the IL-2R beta subunit was both correlated with activation of the endogenous IL-2R alpha gene and critically dependent upon the presence of a serine-rich cytoplasmic domain within IL-2R beta (amino acid residues 267-312). This domain has previously been shown to be essential for IL-2-induced cell growth and may correspond to a binding site for an IL-2R beta-associated tyrosine kinase. Together, these findings suggest that NF-kappa B may play an important role as one intracellular second messenger relaying signals from the plasma membrane to cell nucleus that leads to IL-2-induced activation and growth.

T-lymphocyte proliferation: tyrosine kinases in interleukin 2 signal transduction

Interleukin 2 (IL-2)-induced tyrosine phosphorylation appears to play a major role in IL-2-induced cellular proliferation. Several intracellular substrates including the beta chain of the IL-2 receptor complex (IL-2R beta), raf, MAP2 kinase, the regulatory 83 kDa subunit of phosphatidylinositol-3 kinase and S6 kinases are substrates for the IL-2 receptor activated kinase(s). However, none of the identified members of the IL-2 receptor complex exhibits intrinsic tyrosine kinase activity. Therefore, the IL-2R complex must activate intracellular tyrosine kinases. We have demonstrated that specific tyrosine and serine/threonine kinases are coprecipitated with IL-2 receptor constructs that mediate IL-2-induced cell proliferation but not with those that do not. The IL-2-activated tyrosine kinase appears to be associated with a serine and proline rich intracellular domain which is highly conserved between IL-2R beta and the erythropoietin receptor. Although the responsible kinase has not been identified, lck, fyn, fgr, ltk, hck and lyn can be ruled out as obligatory mediators. Using methods to clone tyrosine kinases from T cells, we have identified potential candidate kinases, including several which had not been known to be expressed by T lymphocytes as well as several unique kinases which had not been previously identified in any cell type.

IL-2-induced signal transduction involves the activation of nuclear NF-kappa B expression

Using electrophoretic mobility shift assays and DNA-protein cross-linking techniques, we demonstrate that IL-2 binding to functional forms of the human IL-2R activates nuclear expression of the eukaryotic transcription factor NF-kappa B. These inductive effects of IL-2 were observed in three different cellular systems including human Jurkat T cells stably transfected with IL-2R beta cDNA, mouse pro-B BA/F3 cells stably expressing human IL-2R beta chains either alone or in combination with human or murine IL-2R alpha chains, and purified primary resting human T cells constitutively displaying small numbers of IL-2R beta molecules. IL-2 activation of nuclear NF-kappa B expression is regulated in part at a post-translational level, involving the rapid translocation of both the 50- and 65-kDa subunits of NF-kappa B from the cytoplasm to the nucleus. However, IL-2 induction also produced an increase in mRNA for NF-kappa B p105, indicating an additional pretranslational component of regulation. In contrast, IL-2 exerts only minor effects on NF-kappa B p65 mRNA expression. IL-2 induction of NF-kappa B through the IL-2R beta subunit was both correlated with activation of the endogenous IL-2R alpha gene and critically dependent upon the presence of a serine-rich cytoplasmic domain within IL-2R beta (amino acid residues 267-312). This domain has previously been shown to be essential for IL-2-induced cell growth and may correspond to a binding site for an IL-2R beta-associated tyrosine kinase. Together, these findings suggest that NF-kappa B may play an important role as one intracellular second messenger relaying signals from the plasma membrane to cell nucleus that leads to IL-2-induced activation and growth.

The third molecule associated with interleukin 2 receptor alpha and beta chain

It is known that the affinity cross-linking study of the human high-affinity Interleukin 2 (IL-2) receptor reveals triplet bands consisting of 70 kDa alpha chain(Tac)-IL-2 and the 90/80 kDa doublet. We found the cell lines lacking the lower band of the doublet in spite of the expression of both alpha and beta chains. No IL-2 binding was detectable in the presence of anti-Tac antibody in these cells. Immunoprecipitation from the cell extract of [125 I] IL-2-cross-linked T cells with anti-beta chain polyclonal IgG detected the upper band, but not lower band of the doublet. These data suggest that the lower band of the doublet represents an unknown IL-2-binding protein (p65) distinct from the beta chain and this molecule may be involved in the intermediate-affinity IL-2 binding together with the beta chain.

Calcitonin inhibits the growth of human gastric carcinoma cell line KATO III

Calcitonin has a wide variety of actions on gastrointestinal function. In this study, we investigated the effects of calcitonin on the growth of human gastric carcinoma cell line KATO III in comparison with those of calcitonin gene-related peptide (CGRP). Calcitonin, but not CGRP, significantly and dose-dependently inhibited the growth of KATO III cells. This inhibition of cell growth was accompanied by an increase in cyclic AMP production. The proliferation of KATO III cells was also inhibited by forskolin and dibutyryl cyclic AMP, although agents which do not stimulate cyclic AMP production had no effect. Furthermore, in the presence of GTP, calcitonin stimulated adenylate cyclase activity in KATO III cell membranes, and this increase was reduced in the absence of GTP. On the other had, neither calcitonin nor CGRP enhanced the turnover of inositolphospholipid or the intracellular Ca2+ level. In addition, 125I-labeled human calcitonin was specifically bound to KATO III cell membranes, and this binding was dose-dependently displaced by unlabeled calcitonin but not CGRP. Furthermore, the specific binding of 125I-labeled human calcitonin to KATO III cell membranes was significantly reduced by addition of GTP but not ATP. These results suggest that calcitonin inhibits the growth of human gastric carcinoma cell line KATO III by stimulating cyclic AMP production via a GTP-dependent process coupled to specific calcitonin receptors.

Irreversible inhibition of thromboxane (TX) A2 synthesis by Y-20811, a selective TX synthetase inhibitor

As Y-20811, sodium (+-)-4-[alpha-hydroxy-5-(1-imidazolyl)-2-methylbenzyl]-3,5-dimethylb+ ++ enzoic acid, has been reported to inhibit serum thromboxane (TX) A2 production with a long duration of action, its mechanism of action was investigated. When [3H]Y-20811 (3 mg/kg) was administered orally to rats, the peak platelet concentration of Y-20811 was obtained 1 hr after the administration, and the T1/2 was 43 hr. The peak plasma concentration of Y-20811 was also obtained 1 hr after administration, but the elimination of Y-20811 from plasma was faster (T1/2 alpha = 1.5 hr, T1/2 beta = 15 hr) than that observed in platelets. Serum TXA2 (estimated as TXB2) production was inhibited significantly from 1 to 72 hr after the oral administration of unlabeled Y-20811 (3 mg/kg), which temporally resembled the change of the platelet Y-20811 concentration. In platelet-rich plasma, [3H]Y-20811 completely inhibited TXA2 production at about 1500 pg/10(9) platelets, and the IC50 level was about 600 pg/10(9) platelets, which was similar to values obtained in ex vivo studies. In addition, inhibition of TXA2 production by Y-20811 still remained after washing the drug-pretreated microsomes, whereas that of dazoxiben completely disappeared. A similar irreversible inhibition of TXA2 production was observed with aspirin. These results suggest that Y-20811 may firmly combine with platelet TX synthetase and may irreversibly inhibit TXA2 production.

Effects of islet amyloid polypeptide (amylin) and calcitonin gene-related peptide (CGRP) on glucose metabolism in the rat

In this study, we compared the effects of islet amyloid polypeptide (IAPP) and calcitonin gene-related peptide (CGRP) on glucose metabolism both in vivo and in vitro in the rat. Intravenous injection of rat CGRP caused a significant increase in plasma glucose concentration with a simultaneous increase in plasma insulin levels, whereas neither IAPP-NH2 nor IAPP-COOH had any effect. Moreover, intravenous infusion of CGRP decreased tolerance to intragastric administration of glucose (O-GTT) without altering plasma insulin levels, but again IAPPs had no effect. On the other hand, 125I-[Tyr0]rat CGRP specifically bound to the liver plasma membrane, and not only CGRP but also IAPP-NH2 dose-dependently displaced the specific binding of 125I-[Tyr0] CGRP, whereas IAPP-COOH had no effect. Conversely, CGRP as well as IAPP-NH2 but not IAPP-COOH evoked dose-dependent activation of adenylate cyclase in the membranes, and these effects were significantly inhibited by a CGRP receptor antagonist, human CGRP-I(8-37). However, neither CGRP nor IAPP-NH2 had any effect on glucose production in rat isolated hepatocytes. These results suggest that (1) IAPP-NH2 but not IAPP-COOH induces adenylate cyclase activation via CGRP receptors on rat liver plasma membranes, and (2) CGRP might not involve its action on the liver in the changes of glucose metabolism.

Vitamin A: differentiating action on gastric cancer cells and gastric mucosal cells in elderly people

Since RA is effective only in gastric mucosal cells but not in isolated parietal cells, it is strongly suggested that RA acts on multi-potential stem cells in the gastric mucosa, facilitating their differentiation into mature parietal cells. Moreover, although RA was very effective in newborn rats as well as in young people, responsiveness to RA is decreased in the elderly people especially with atrophic gastritis. This unresponsiveness in the elderly people might be involved in the development of gastric cancer.

Human T-cell leukemia virus type I Tax induces expression of the Rel-related family of kappa B enhancer-binding proteins: evidence for a pretranslational component of regulation

The Tax protein of the human T-cell leukemia virus type I (HTLV-I) serves as a potent transcriptional activator of its own long terminal repeat as well as select cellular genes, including interleukin-2 and the alpha subunit of the interleukin-2 receptor. Tax activation of these two growth-related genes appears to involve the induced nuclear expression of DNA-binding proteins that specifically engage related kappa B enhancer elements present in the 5' regulatory regions of these genes. In human T cells, kappa B enhancer-binding activity has been discerned as an unexpectedly large family of UV cross-linked nucleoprotein adducts, termed p50, p55, p75, and p85. The protein components of each of these DNA-protein adducts have been shown to share structural similarity with the v-rel oncogene product. The p55 adduct is composed of the 50-kDa subunit of NF-kappa B derived from a 105-kDa precursor polypeptide, while the p50 adduct contains a smaller protein that is closely related to NF-kappa B p50. The p75 adduct contains the 65-kDa subunit of NF-kappa B, while the p85 adduct is composed of the human c-rel proto-oncogene product. We now demonstrate that HTLV-I Tax, in the absence of other viral pX gene products, is capable of inducing the nuclear expression of all four of these kappa B-binding proteins in human T cells, with most marked effects involving c-Rel and NF-kappa B p65. Tax induction of the nuclear expression of c-Rel and NF-kappa B p50 is regulated, at least in part, at a pretranslational level involving increases in c-rel and NF-kappa B p105 mRNA expression. To study the pattern of expression of these kappa B-specific proteins in cells infected with the whole HTLV-I, seven cloned HTLV-I-infected T-cell lines were established from the peripheral blood of patients with adult T-cell leukemia. Of note, only three of these seven cell lines produced Tax, and c-rel mRNA and nuclear protein expression was confined to these three cell lines. In contrast, NF-kappa B p50 and NF-kappa B p65 were constitutively expressed in the nuclei of all seven of the HTLV-I-infected cell lines, even in the absence of detectable Tax or other viral gene expression. These findings raise the possibility of an alternate, Tax-independent pathway for the induced nuclear expression of NF-kappa B p50 and NF-kappa B p65 following HTLV-I infection.

The IL-2 receptor alpha-chain alters the binding of IL-2 to the beta-chain

The binding of IL-2 to its high affinity receptor results in the formation of the ternary complex consisting of IL-2, alpha-chain (p55, Tac) and beta-chain (p75). We studied the role of alpha-chain in IL-2 binding to the high affinity receptor using IL-2 analog Lys20 which was made by the substitution of Lys for Asp20 of wild-type rIL-2. Lys20 bound to MT-1 cells solely expressing alpha-chain at low affinity, but did not bind to YT-2C2 cells which solely expressed beta-chain. However, direct binding of radiolabeled Lys20 to ED515-D cells, an HTLV-I-infected and IL-2-dependent T cell line, revealed both high affinity and low affinity binding although the Kd value of high affinity binding was 50 to 100 times higher than that of the high affinity binding of wild-type rIL-2. High affinity binding of Lys20 was completely blocked by 2R-B mAb recognizing IL-2R beta-chain. Anti-Tac mAb recognizing IL-2R alpha-chain abolished all of the specific Lys20 bindings. In contrast to the replacement of cell bound 2R-B mAb with wild-type rIL-2 at 37 degrees C, the addition of an excess of Lys20 did not cause the detachment of cell-bound radiolabeled or FITC-labeled 2R-B mAb. Consistent with the results of binding studies, Lys20 induced the proliferation of ED515-D cells, but not large granular lymphocyte leukemic cells. The growth of ED-515D cells was completely suppressed by either anti-Tac mAb or 2R-B mAb. These results strongly suggest that coexpression of the IL-2R alpha- and beta-chains alters the binding affinity of Lys20 and that the interaction between IL-2 and the alpha-chain is a key event in the formation of the IL-2/IL-2R ternary complex.

The IL-2 receptor alpha-chain alters the binding of IL-2 to the beta-chain

The binding of IL-2 to its high affinity receptor results in the formation of the ternary complex consisting of IL-2, alpha-chain (p55, Tac) and beta-chain (p75). We studied the role of alpha-chain in IL-2 binding to the high affinity receptor using IL-2 analog Lys20 which was made by the substitution of Lys for Asp20 of wild-type rIL-2. Lys20 bound to MT-1 cells solely expressing alpha-chain at low affinity, but did not bind to YT-2C2 cells which solely expressed beta-chain. However, direct binding of radiolabeled Lys20 to ED515-D cells, an HTLV-I-infected and IL-2-dependent T cell line, revealed both high affinity and low affinity binding although the Kd value of high affinity binding was 50 to 100 times higher than that of the high affinity binding of wild-type rIL-2. High affinity binding of Lys20 was completely blocked by 2R-B mAb recognizing IL-2R beta-chain. Anti-Tac mAb recognizing IL-2R alpha-chain abolished all of the specific Lys20 bindings. In contrast to the replacement of cell bound 2R-B mAb with wild-type rIL-2 at 37 degrees C, the addition of an excess of Lys20 did not cause the detachment of cell-bound radiolabeled or FITC-labeled 2R-B mAb. Consistent with the results of binding studies, Lys20 induced the proliferation of ED515-D cells, but not large granular lymphocyte leukemic cells. The growth of ED-515D cells was completely suppressed by either anti-Tac mAb or 2R-B mAb. These results strongly suggest that coexpression of the IL-2R alpha- and beta-chains alters the binding affinity of Lys20 and that the interaction between IL-2 and the alpha-chain is a key event in the formation of the IL-2/IL-2R ternary complex.

Presence of histamine H2-receptors on human gastric carcinoma cell line MKN-45 and their increase by retinoic acid treatment

Histamine dose-dependently stimulated cyclic AMP production in human gastric carcinoma cell line MKN-45, and this effect was inhibited by cimetidine but not by pyrilamine. Moreover, not only histamine but also cimetidine displaced the specific binding of [3H]tiotidine to these cells, whereas pyrilamine had no effect. On the other hand, pretreatment of MKN-45 cells with retinoic acid (RA) significantly enhanced histamine-induced increase of cyclic AMP production, although the cyclic AMP response to either forskolin or NaF was not affected. Finally, RA treatment increased the number of histamine receptor without altering its affinity. Thus, it appears that histamine H2-receptors are present on MKN-45 cells, and that RA treatment enhances the action of histamine on these cells by increasing the number of H2-receptors.

Colonic mucosal interleukin-6 in inflammatory bowel disease

Interleukin-6, a cytokine produced by various cell types, has a major role in inflammatory and immunological reactions. To define its potential role in inflammatory bowel disease, its concentrations in endoscopic biopsy samples from patients with ulcerative colitis and Crohn's disease were measured. The involved colonic mucosa from active disease was found to contain significantly larger amounts of interleukin-6 than that from inactive disease or normal controls. Colonic mucosal interleukin-6 levels correlated well with the grade of macroscopic inflammation, especially in patients with ulcerative colitis. The levels of interleukin-6 decreased in parallel with clinical improvement following the start of therapy in patients with both forms of inflammatory bowel disease. Mucosal interleukin-6 is thus concluded to accurately reflect the degree of colonic inflammation and may be importantly associated with inflammatory and immunological phenomena seen in inflammatory bowel disease.

Stereoselective acyl glucuronidation and glucosidation of pranoprofen, a 2-arylpropionic acid derivative, in mice in vivo

Following the oral administration of RS(+/-)-pranoprofen to mice at a dose of 25 mg/kg, 10.7% of the acyl glucuronide and 46.4% of the acyl glucoside of pranoprofen were excreted in the urine within 24 h. The recovery of acyl glucoside in the urine decreased relative to that of acyl glucuronide at increasing doses (100, 200 mg/kg). Following the oral administration of S(+)-pranoprofen to mice at a dose of 25 mg/kg, 5.0% of the acyl glucuronide and 56.5% of the acyl glucoside were excreted in the urine within 24 h, while 10.8% of the acyl glucuronide and 13.9% of the acyl glucoside were excreted after the oral administration of R(-)-pranoprofen, respectively. The absolute configuration of the aglycone of acyl glucuronide was almost R(-)-enantiomer (92.5-96.1%) in the 0-24 h urine, whereas that of acyl glucoside contained 15.3-24.7% of S(+)-enantiomer after the oral administration of R(-)-pranoprofen. On the other hand, only the S(+)-isomer was found as the aglycone of both acyl glucuronide and glucoside after the oral administration of S(+)-pranoprofen. The present results showed that stereoselective conjugation was observed in glucosidation in mice. Nevertheless, a dose-dependent shift in glucuronidation and glucosidation was found for both the administrations of S(+)- and R(-)-enantiomers as well as RS(+/-)-pranoprofen. Also a chiral inversion of R(-)-enantiomer to S(+)-antipode may occur slightly but significantly in mice.

Species differences in absorption, metabolism and excretion of pranoprofen, a 2-arylpropionic acid derivative, in experimental animals

Absorption, metabolism and excretion of 2-(5H-[1]benzopyrano-[2,3-b]pyridin-7-yl)propionic acid (pranoprofen), an anti-inflammatory drug, were investigated in mice, rats, guinea pigs and rabbits using 14C-labeled compound ( [14C]pranoprofen) at a dose of 5 mg/kg. After the oral administration of [14C]pranoprofen the radioactivity was rapidly and almost completely absorbed from the digestive organs of the animals tested. The radioactivity in the blood reached the maximum at 30--60 min after the oral administration of [14C]pranoprofen in all species tested, and the biological half-lives of the radioactivity were 4.1 h in rats, 2.6 h in guinea pigs, 1.3 h in mice and 0.9 h in rabbits, respectively. When [14C]pranoprofen was orally administered, urinary and fecal excretions of the radioactivity within 3 d were 81.1% and 18.7% of the dose in mice, 51.5% and 39.4% in rats, 81.8% and 9.0% in guinea pigs, and 93.2% and 3.6% in rabbits, respectively. A major metabolite of pranoprofen was its acyl glucuronide in rats, guinea pigs and rabbits. However, it was shown that acyl glucosidation is also a predominant metabolic pathway of pranoprofen in mice.

Dose-dependent shift in acyl glucuronidation and glucosidation of pranoprofen, a 2-arylpropionic acid derivative, in mice in vivo

Following the oral administration of [14C]pranoprofen to mice, 70-80% of radioactivity was excreted in the urine, and 15-25% in the feces within 3 d at 5, 25, 50, 100 and 200 mg/kg. This showed that no significant change in urinary and fecal excretion was observed among these doses. The radioactivity levels in the blood also increased in proportion to the doses, indicating that no repression of the absorption of pranoprofen was found even at increased doses. The major metabolites in mouse urine were acyl glucuronide and the glucoside of pranoprofen. At low doses acyl glucoside was predominantly excreted in urine, whereas acyl glucoside decreased relative to acyl glucuronide at increased doses. Although 43.2% of the acyl glucoside was recovered in the 24 h urine samples after the intravenous administration of acyl glucuronide, no acyl glucuronide was found in the urine after the intravenous administration of acyl glucoside. These results demonstrated the interesting observation that pranoprofen had a preference for glucosidation rather than glucuronidation in mice at low doses in spite of having a higher capacity of glucuronidation.

Acyl glucuronidation and glucosidation of pranoprofen, a 2-arylpropionic acid derivative, in mouse liver and kidney homogenates

The formation of acyl glucuronide and glucoside of 2-(5H-[1]benzopyrano[2,3-b]pyridin-7-yl)propionic acid (pranoprofen), an anti-inflammatory drug, was studied in homogenates and microsomes of mouse tissues by using S(+)-, R(-)- and RS(+/-)-pranoprofen. Acyl glucuronidation occurred mainly in the liver, whereas acyl glucosidation was predominant in the kidney. Furthermore, both conjugations occurred by enzymatic transfer of glucuronic acid of uridine diphosphate glucuronic acid (UDPGA) and glucose of uridine diphosphate glucose (UDPG) to pranoprofen, respectively. No conjugation reactions were observed in the lung, plasma or gut. The amount of conjugates in the liver and kidney increased by the prolongation of the incubation times and reached the maximum at 15-30 min for glucuronidation and 45 min for glucosidation. After that, both conjugates decreased with the lapse of time. Both acyl conjugates were the least stable in the liver, then in the kidney and the most stable in the plasma. In the liver, acyl glucoside was converted to acyl glucuronide and pranoprofen in the presence of UDPGA, but only a small amount of acyl glucuronide was changed to acyl glucoside in the kidney in spite of the presence of UDPG. In the kidney, acyl glucoside decreased relative to acyl glucuronide at increasing doses for both S(+)- and R(-)-pranoprofen, but the concentration of acyl glucoside was much higher for S(+)-pranoprofen than R(-)-enantiomer 1 h after the oral administration of S(+)- and R(-)-pranoprofen. No acyl glucoside was detected in the liver and plasma. Although only a small difference in acyl glucuronidation in the liver was observed between S(+)- and R(-)-enantiomers, acyl glucosidation in the kidney occurred more predominantly for S(+)-pranoprofen than for the R(-)-enantiomer.

[Possible mechanisms of hematoma formation in the urinary tracts in a patient with idiopathic thrombocytopenic purpura]

A 30-year-old female was admitted to our hospital complaining of hematuria and right flank pain in September, 1987. She had been diagnosed idiopathic thrombocytopenic purpura in 1980, and had similar symptoms before. Hematoma in the right ureter was demonstrated by retrograde pyelography and CT-scanning, and these symptoms improved within one month. Each activity of plasma clotting factors was within normal limits. Enzymatic studies of the urine revealed low values of plasmin-, urokinase-, and kallikrein-like activities in both excerbation and remission. These hemorrhagic tendencies might have been the result of marked thrombocytopenia: After bleeding into the urinary tracts began, the bleeding would tend to form hematoma because of elevated clotting activity; then hematoma would grow due to decreased urine fibrinolytic activities. This suggested that a decline of fibrinolysis in urine might have a promoting effect on the process of hematoma formation.

Role of alpha chain-IL-2 complex in the formation of the ternary complex of IL-2 and high-affinity IL-2 receptor

Using anti-Tac (anti-alpha chain) and 2R-B (anti-beta chain) antibodies, we studied the roles of IL-2 receptor subunits (alpha and beta chains) in the formation of IL-2 and high-affinity IL-2 receptor complex, which is the initial event of IL-2 induced T cell growth. High-affinity IL-2 binding which was undetectable in the presence of 2R-B antibody at 4 degrees C became fully detectable when examined at 37 degrees C, which explained the lack of inhibition by 2R-B antibody of IL-2-induced proliferation of the cells expressing high-affinity IL-2 receptor. We further studied the mechanism of the 'reappearance' of high-affinity IL-2 binding in the presence of 2R-B antibody. The addition of IL-2 to the cells preincubated with radiolabeled or fluorescence-labeled 2R-B antibody resulted in a marked decrease in the antibody bound to the cells expressing high-affinity IL-2 receptor at 37 degrees C. This decrease was blocked by the presence of anti-Tac antibody, which inhibited IL-2 binding to alpha chain, but not by 7G7/B6 antibody, which recognized a non-IL-2 binding site of its chain. Furthermore, the decrease in cell-bound 2R-B antibody was not due to the internalization of beta chain-2R-B antibody complex, because the amount of cell-bound Mik-beta3 antibody recognizing a non-IL-2 binding epitope of beta chain remained unchanged, nor to the inhibition by simple competitive binding of IL-2 molecules to beta chain as judged from comparative studies of competitive binding inhibition. Taking these data together, the reappearance of high-affinity IL-2 binding was considered to be caused by the replacement of 2R-B antibody at the IL-2 binding site of beta chain by alpha chain-mediated IL-2, and it was strongly suggested that alpha chain-IL-2 complex has a key role in the formation of the ternary complex of IL-2 and high-affinity IL-2 receptor. alpha chain may function as a dimension converter of IL-2 to effectively deliver IL-2 molecules to a relatively small number of beta chains in the dynamics of the formation of high-affinity IL-2 binding in T cells.

Altered HLA antigens expressed on T and B lymphocytes of adult T-cell leukemia/lymphoma patients and their relatives

The HLA types of peripheral blood lymphocytes (PBL) of 36 adult T-cell leukemia/lymphoma (ATLL) patients were examined and compared with those of 45 healthy relatives of these patients, and with those of 10 non-ATLL families including 80 healthy members. Thirty-one percent of ATLL patients showed either a gain or a loss of HLA antigens determined by the presence of alien HLA antigens or the absence of inherent HLA antigens deduced from familial haplotype analysis. The antigen specificity of HLA gained or lost was variable and differed from case to case among ATLL patients. Although the gain of HLA was detected only in ATLL patients, the loss of HLA was found both in ATLL patients and in asymptomatic healthy relatives. The rate of HLA loss in ATLL patients (8.4%) and their relatives (17.8%) was much higher than in relatives of non-ATLL patients (1.1%). The HLA gain and loss revealed in the PBL of ATLL patients were confirmed by altered HLA phenotypes in the cloned T and B cells established from ATLL patients. Our results suggest that latently infecting HTLV-I may induce altered HLA phenotypes in T and B cells, primarily with loss of HLA antigens in a population of asymptomatic virus carriers, and secondarily with a gain of HLA antigens after the development of ATLL.