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Biomedical subjects

K Sawada

Publications and source records attributed to K Sawada.

At least 91 records · Page 5Linked to original sources
PubMed2000

Effective high-dose chemotherapy combined with CD34+-selected autologous peripheral blood stem cell transplantation in a patient with cutaneous CD30-negative large T cell lymphoma.

Generalized multiple cutaneous tumors developed in a 60-year-old Japanese man. Skin biopsy revealed atypical large T lymphocytes infiltrating the dermis. CD30 staining was negative in the tumor cells. The diagnosis of CD30-negative cutaneous large T cell lymphoma was made. Axial and inguinal lymphadenopathy was present, but there was no evidence of bone marrow involvement. Seven cycles of chemotherapy and local electron beam irradiation were administered and complete remission (CR) was attained. As CD30-negative cutaneous large T cell lymphoma has a poor prognosis despite intensive chemotherapy, high-dose chemotherapy followed by CD34+-selected autologous peripheral blood stem cell transplantation (CD34+-APBSCT) was prescribed. The clinical course after CD34+-selected APBSCT was complicated with CMV infection occurring twice but administration of ganciclovir resolved the symptoms. He has remained in CR for 16 months after CD34+-APBSCT. This appears to be the first case report of CD34+-APBSCT in a patient with CD30-negative cutaneous large T cell lymphoma. Bone Marrow Transplantation (2000) 25, 1315-1317.

Antigens, CD34↗
PubMed2000

Large scale purification of human blood CD34+ cells from cryopreserved peripheral blood stem cells, using a nylon-fiber syringe system and immunomagnetic microspheres.

Isolation of large numbers of human peripheral blood CD34+ cells could lead to therapeutic applications, including purging of malignant cells from blood cell transplantations, purging of T cells from allogeneic bone marrow, and even blood cell transplantation. This procedure has limitations if there are not sufficient numbers of progenitor cells in the leukapheresis concentrates available for selection after detection of tumor cells in apheresis products. Use of frozen/thawed peripheral blood mononuclear cell (PBMC) samples would make feasible pooling of two or even more stem cell harvests collected at different time points and the total number of CD34+ progenitor cells available would increase. We established an efficient method for purification of CD34+ cells from cryopreserved apheresis products, using a nylon-fiber syringe system and immunomagnetic microspheres. We compared purity, recovery rate and clonogenicity of CD34+ cells purified from fresh (n = 22) and cryopreserved apheresis products (n = 14), using a nylon-fiber syringe system and immunomagnetic microspheres. The purity of CD34+ cells from cryopreserved products was less than that from fresh products (85.9 +/- 14.4% vs 94.6 +/- 10.0%), but the recovery rate of CD34+ cells and colony-forming cells was comparable between fresh and cryopreserved products. One patient underwent grafting with peripheral blood CD34+ cells selected after freezing, with good success. Therefore, these cells are capable of rapidly reconstituting hematopoiesis after high-dose chemotherapy. Bone Marrow Transplantation (2000) 26, 787-793.

Antigens, CD34↗
PubMed2000

Nucleotide and amino-acid sequences of a new-type pectate lyase from an alkaliphilic strain of Bacillus.

A pectate lyase (pectate transeliminase; EC 4.2.2.2), designated Pel-15E, was purified to homogeneity from a culture broth of alkaliphilic Bacillus sp. strain KSM-P15. The purified enzyme had a molecular mass of approximately 33 kDa, as determined by SDS/PAGE, and a pI of approximately pH 9.2. Pel-15E exhibited optimum activity at pH 10.5 and 50-55 degrees C in glycine/NaOH buffer. Pel-15E had an absolute requirement for Ca2+ ions for manifestation of the enzymatic activity and trans-eliminated poly(galacturonic) acid, most likely by endo-type cleavage. A gene for the enzyme, which was cloned using the shotgun method and sequenced, contained a 960-bp ORF encoding 320 amino acids. The mature enzyme (286 amino acids, 32 085 Da) from the deduced amino-acid sequence showed quite low homology to known Pels from various microorganisms with 16.1-20.4% identity. Furthermore, we were not able to find any conserved regions in the sequence of Pel-15E when aligned with the sequences of other enzymes from the established Pel superfamily. However, Pel-15E had some regions that were homologous to PelA from Azospirillum irakense with 39.8% identity. Based on their amino-acid sequence homology, Pel-15E and PelA appear to belong to a new class of Pel family, although the enzymatic properties of both enzymes were quite different.

Amino Acid Sequence↗
PubMed2000

Neuronal and vascular localization of histamine N-methyltransferase in the bovine central nervous system.

Histamine N-methyltransferase (HMT) (EC 2.1.1.8) plays a crucial role in the inactivation of the neurotransmitter histamine in the CNS. However, the localization of HMT remains to be determined. In the present study, we investigated immunohistochemical localization of HMT in the bovine CNS using a polyclonal antibody against bovine HMT. The HMT-like immunoreactivity was observed mainly in neurons. Strongly immunoreactive neurons were present in the oculomotor nucleus and ruber nucleus in the midbrain, the facial nucleus in the pons, the dorsal vagal nucleus and hypoglossal nucleus in the medulla oblongata and in the anterior horn as well as intermediolateral zone of the spinal cord. Intermediately immunoreactive neurons were present in the piriform cortex and the inferior olivary nucleus. The grey matter of the forebrain regions was diffusely and faintly stained. In the cerebellum and the striatum, the nerve fibres in the white matter were positive. The tuberomammillary nucleus, where histaminergic neurons are present, were weakly positive. The other immunoreactive structures in the CNS were blood vessels. Almost all of the blood vessel walls, irrespective of whether they were arterial or venous, were variably stained. The glial fibrillary acidic protein- (GFAP-) immunoreactive astrocytes were not stained. These findings indicated that histamine released from histaminergic nerve terminals or varicose fibres is methylated mainly in postsynaptic or extrasynaptic neurons rather than in astrocytes. The localization of HMT in the blood vessel wall may mean that blood-borne histamine and histamine released from mast cells associated with the blood vessels are catabolized in this structure.

Animals↗
PubMed2000

Purification and characterization of a trypsin-like serine proteinase from rat brain slices that degrades laminin and type IV collagen and stimulates protease-activated receptor-2.

A trypsin-like serine proteinase was purified from the incubation medium of rat brain slices by gelatin zymography. The purification consisted of ammonium sulfate precipitation, benzamidine-Sepharose 6B affinity chromatography, and carboxymethyl-cellulose and gel filtration chromatographies. The gelatinolytic activity, identified at 22 kDa (P22) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions, was eluted as one active peak throughout the purification, and the final preparation gave a single protein peak on reverse-phase HPLC. Diisopropyl fluorophosphate, benzamidine, p-toluenesulfonyl-L-lysine chloromethyl ketone, and aprotinin completely inhibited the activity of P22, whereas phenanthroline, p-toluene-sulfonyl-L-phenylalanine chloromethyl ketone, and elastinal did not. P22 efficiently digested the extracellular matrix proteins laminin and type IV collagen. P22 produced an increase in intracellular Ca2+ concentration in A172 glioblastoma, which was desensitized through prior stimulation with protease-activated receptor-2 agonist peptide SLIGKV, indicating that P22 can stimulate protease-activated receptor-2. Rat brain penetration injury induced gelatinolytic activity in the lesioned area whose molecular size was consistent with that of P22. These results indicated that on incubation of rat brain slices, a trypsin-like serine proteinase was secreted into the medium that was capable of digesting extracellular matrix and stimulating protease-activated receptor-2. It is suggested that the gelatinolytic activity induced by brain injury might be that of P22.

Animals↗
PubMed2000

In vitro evaluation study of the membrane autotransfusion system experimental prototype: MATS-I.

Membrane Autotransfusion System (MATS) utilizing plasmapheresis technology has been developed in our laboratory. A specially designed polyethylene hollow fiber membrane was utilized. This study was conducted to evaluate performance of the first experimental prototype, MATS-I. The results of this study showed that the MATS-I could concentrate diluted blood at 10% of the initial hematocrit concentration (HCTi) into over 40% after passing through the system at a transmembrane pressure of 70 mm Hg. Moreover, the MATS-I can continuously treat 10,000 ml of diluted blood at various HCTi levels without deteriorating its performances. Even though the MATS-I met all required performances as an autotransfusion system, several areas of improvement of the system were necessary to meet various clinical needs. The next prototype, MATS-II, can be designed based on experiences obtained from the MATS-I. The MATS is smaller, more atraumatic and continuous, and is a faster system when compared to the currently available centrifugal autotransfusion devices.

Animals↗
PubMed2000

Development of the membrane autotransfusion system prototype-II: MATS-II.

This article is the second of a two-part series describing a membrane autotransfusion system, MATS, utilizing plasmapheresis technology. Based on experiences obtained from the first prototype (MATS-I), optimum blood filtration parameters with refined blood and flux pump synchronization were put into an original CPU-board and loaded on a miniaturized, self-operative, and preclinical prototype (MATS-II). This study was conducted to evaluate the MATS-II using diluted blood of various hematocrit concentrations. The results proved that this device could concentrate 4,000-10,000 ml of various hematocrit concentrations into higher than 40% while automatically controlling the flow speed from 250 to 400 ml/min. Also, no significant damage was generated to the red blood cells (RBC). Moreover, the MATS-II salvaged over 90% of platelets together with the RBC. These results suggest that the MATS-II achieves all clinical requirements of an autotransfusion device; it is a continuous hemoconcentration device with minimum damage to cellular components of the blood.

Animals↗
PubMed2000

IL-18 and IL-12 induce intestinal inflammation and fatty liver in mice in an IFN-gamma dependent manner.

BACKGROUND: In murine models of inflammatory bowel disease, colonic inflammation is considered to be caused by an aberrant Th1-type immune response. AIM: To investigate if systemic administration of interleukin (IL)-12 and IL-18 to wild-type BALB/c mice induces liver injury and intestinal inflammation, and if pathological changes are observed, what cytokines are involved. METHODS: Mice (BALB/c-wild-type (wt), MRL-lpr/lpr, BALB/c-interferon gamma knock out (IFN-gamma KO), C57BL/6-inducible nitric oxide synthase (iNOS) KO, and BALB/c tumour necrosis factor alpha (TNF-alpha) KO) were injected intraperitoneally each day with IL-12 (20 ng/g/mouse) and/or IL-18 (200 ng/g/mouse). RESULTS: Administration of IL-12 and IL-18 to BALB/c-wt mice induced prominent intestinal mucosal inflammation and fatty liver, leading to piloerection, bloody diarrhoea, and weight loss. IL-12 and IL-18 induced striking elevations in serum levels of IFN-gamma that caused NO production, although increased NO had no exacerbating effect on mice. Moreover, iNOS KO mice, or MRL lpr/lpr mice lacking functional Fas were equally susceptible to IL-12 and IL-18. Administration of IL-12 and IL-18 did not induce TNF-alpha production in wild-type mice, and the same treatment to TNF-alpha KO mice induced intestinal mucosal inflammation. Furthermore, they had diffuse and dense infiltration of small fat droplets in their hepatocytes associated with an increase in serum levels of liver enzymes. In contrast, the same treatment in IFN-gamma KO BALB/c mice and iNOS KO mice did not induce these changes. CONCLUSIONS: Our study strongly indicates that IL-18 together with IL-12 induces intestinal mucosal inflammation in an IFN-gamma dependent but TNF-alpha, NO, and Fas ligand independent manner, and fatty liver is dependent on IFN-gamma and NO.

Animals↗
PubMed2000

Functional expression of novel peptide transporter in renal basolateral membranes.

We examined the peptide transport activity in renal basolateral membranes. [(14)C]glycylsarcosine (Gly-Sar) uptake in rat renal cortical slices was saturable and inhibited by excess dipeptide and aminocephalosporin cefadroxil. When several renal cell lines were screened for the basolateral peptide transport activity, Madin-Darby canine kidney (MDCK) cells were demonstrated to have the greatest transport activity. [(14)C]Gly-Sar uptake across the basolateral membranes of MDCK cells was inhibited by di- and tripeptide and decreased with decreases in extracellular pH from 7.4 to 5.0. The Michaelis-Menten constant value of [(14)C]Gly-Sar uptake across the basolateral membranes of MDCK cells was 71 microM. The basolateral peptide transporter in MDCK cells showed several different [(14)C]Gly-Sar transport characteristics in growth dependence, pH profile, substrate affinity, and sensitivities to chemical modifiers from those of the apical H(+)-peptide cotransporter of MDCK cells. The findings of the present investigation indicated that the peptide transporter was expressed in the renal basolateral membranes. In addition, from the functional characteristics, the renal basolateral peptide transporter was suggested to be distinguishable from known peptide transporters, i.e., H(+)-peptide cotransporters (PEPT1 and PEPT2) and the intestinal basolateral peptide transporter.

4-Chloromercuribenzenesulfonate↗
PubMed2000

Immunohistochemical localization of histamine N-methyltransferase in guinea pig tissues.

Histamine plays important roles in gastric acid secretion, inflammation, and allergic response. Histamine N-methyltransferase (HMT; EC 2.1.1.8) is crucial to the inactivation of histamine in tissues. In this study we investigated the immunohistochemical localization of this enzyme in guinea pig tissues using a rabbit polyclonal antibody against bovine HMT. The specificity of the antibody for guinea pig HMT was confirmed by Western blotting and the lack of any staining using antiserum preabsorbed with purified HMT. There was strong HMT-like immunoreactivity (HMT-LI) in the epithelial cells in the gastrointestinal tract, especially in the gastric body, duodenum, and jejunum. The columnar epithelium in the gallbladder was also strongly positive. Almost all the myenteric plexus from the stomach to the colon was stained whereas the submucous plexus was not. Other strongly immunoreactive cells included the ciliated cells in the trachea and the transitional epithelium of the bladder. Intermediately immunoreactive cells included islets of Langerhans, epidermal cells of the skin, alveolar cells in the lung, urinary tubules in the kidney, and epithelium of semiferous tubules. HMT-LI was present in specific structures in the guinea pig tissues. The widespread distribution of HMT-LI suggests that histamine has several roles in different tissues.

Animals↗
PubMed2000

Goosecoid suppresses cell growth and enhances neuronal differentiation of PC12 cells.

In all vertebrate species, the homeobox gene goosecoid serves as a marker of the Spemann organizer tissue. One function of the organizer is the induction of neural tissue. To investigate the role of goosecoid in neuronal differentiation of mammalian cells, we have introduced goosecoid into PC12 cells. Expression of goosecoid resulted in reduced cell proliferation and enhanced neurite outgrowth in response to NGF. Expression of goosecoid led to a decrease in the percentage of S-phase cells and to upregulation of the expression of the neuron-specific markers MAP-1b and neurofilament-L. Analysis of goosecoid mutants revealed that these effects were independent of either DNA binding or homodimerization of Goosecoid. Coexpression of the N-terminal portion of the ets transcription factor PU.1, a protein that can bind to Goosecoid, repressed neurite outgrowth and rescued the proliferation of PC12 cultures. In contrast, expression of the bHLH transcription factor HES-1 repressed goosecoid-mediated neurite outgrowth without changing the proportion of S-phase cells. These results suggest that goosecoid is involved in neuronal differentiation in two ways, by slowing the cell cycle and stimulating neurite outgrowth, and that these two events are separately regulated.

Animals↗
PubMed2000

A new high-alkaline and high-molecular-weight pectate lyase from a Bacillus isolate: enzymatic properties and cloning of the gene for the enzyme.

A pectate lyase (Pel; pectate transeliminase: EC4.2.2.2.), designated Pel-15H, was found in an alkaline culture of Bacillus sp. strain KSM-P15 and purified to homogeneity by sequential column chromatographies. The molecular weight of the enzyme determined by SDS-polyacrylamide gel electrophoresis was approximately 70,000 and the pI was around pH 4.6. Pel-15H randomly trans-eliminated polygalacturonate in the presence of Ca2+ ions, and the maximum activity was observed at pH 11.5 and at 55 degrees C in glycine-NaOH buffer. The gene for Pel-15H was cloned and sequenced, and the structural gene contained a 2,031-bp open reading frame that encoded 677 amino acids including a possible 28-amino-acid signal sequence. The mature enzyme (649 amino acids, molecular weight 69,550) showed very low similarity to Pels from Bacillus with 12.7-18.2% identity. Interestingly, part of the amino acid sequence of Pel-15H had fairly high similarity only to an N-terminal half of PelL and a C-terminal half of PeIX from Erwinia chrysanthemi 3937, and a C-terminal half of PeIX from E. chrysanthemi EC16 (approximately 35% identity for all).

Amino Acid Sequence↗
PubMed2000

Diagnostic efficacy of three-dimensional images by helical CT for lesions in the maxillofacial region.

The purpose of this study was to evaluate the efficacy of three-dimensional (3-D) images produced with a helical CT for the diagnosis of lesions occurring in the maxillofacial region. Thirty-four patients, who had lesions in the maxillofacial region, were examined by plain radiography (intra and extraoral) and the helical CT. Further, 3-D images were reconstructed from the data provided by the helical CT using the volume rendering method. These images were compared with plain radiographic images and conventional two-dimensional (2-D) CT images in terms of the information they provided for diagnosis. Using the 3-D images for tumors, bone destruction, inner components, extent of the lesion,the relationship between the lesion and surrounding anatomical landmarks, and the roots of the adjacent teeth were observed in overall views. We conclude that 3-D images produced by helical CT may provide useful information for the diagnosis of lesions.

Adult↗
PubMed2000

[Reactivation of hepatitis B virus after autologous peripheral blood stem cell transplantation in patients with positive hepatitis B surface antibodies].

Hepatitis B virus (HBV) reactivation in patients with positive hepatitis B surface antibody (HBsAb) has been reported in some cases of allogenic bone marrow transplantation, acquired immunodeficiency syndrome (AIDS), and organ transplantation. However, to our knowledge, no reports have been made on the frequency and risk factors involved in HBV reactivation after autologous peripheral blood stem cell transplantation (APBSCT). Forty seven patients who underwent APBSCT were retrospectively analyzed. Three patients who were HBsAb positive before APBSCT contracted post-transplant HBV acute hepatitis. All 3 patients had multiple myeloma. HBV DNA could not be demonstrated in preserved samples of transfused blood. Therefore, we speculated that reactivation of latent HBV had occurred. The 3 patients with HBV hepatitis had relatively lower titers of pre-transplant HBsAb, and the total dose of steroids they received after APBSCT was significantly higher than for other patients who did not experience post-transplant HBV reactivation. There were no significant differences in pre-transplant hepatitis B core antibody (HBcAb) titer or total post-transplant blood transfusion volume. Our study suggested that immunocompromised states, especially those induced by high-dose steroid therapy, may allow the reactivation of HBV after APBSCT, even in patients who had HBsAb before APBSCT.

Adolescent↗
PubMed2000

[Effective chemotherapy with docetaxel in a patient with breast cancer who had progressed after high-dose chemotherapy with autologous peripheral blood stem cell transplantation (APBSCT)].

A 39-year-old female underwent mastectomy for breast cancer in December 1995. However, two years later, she relapsed with multiple bone metastases. Only a partial response was obtained despite tandem high-dose chemotherapy with autologous peripheral blood stem cell transplantation (APBSCT). Disease progression with bone pain and an increasing in the level of serum NCC-ST439 occurred 5 months after APBSCT. Salvage chemotherapy with docetaxel 60 mg/m2 reduced her symptoms, and the level of serum NCC-ST439 decreased to within the normal range. Ten cycles of docetaxel administration were repeated without severe adverse reactions in an outpatient setting for 10 months. There is little information regarding treatment after relapse from APBSCT for breast cancer. Docetaxel may be an effective agent for patients in such a setting.

Adult↗
PubMed2000

[Successful hematologic reconstitution using CD34+ cells positively selected from cryopreserved autologous peripheral blood stem cells in a patient with malignant lymphoma].

Clinical use of CD34+ cells positively selected from cryopreserved peripheral blood stem cells (PBSC) has been limited, and there have been only a few reports of this procedure, mainly because clump formation decreases the proportion of CD34+ cells that can be recovered. A 49-year-old Japanese woman with non-Hodgkin's lymphoma (NHL) (follicular mixed, B cell, stage IVA) was treated with seven cycles of conventional chemotherapy and achieved partial remission. During hematopoietic recovery after the seventh course of chemotherapy, PBSC were harvested by continuous leukapheresis and cryopreserved. However, clonal rearrangement of the immunoglobulin heavy chain gene was detected in the PBSC by Southern blot analysis. After high-dose chemotherapy, CD34+ cells were positively immunoselected from the cryopreserved PBSC and infused into the patient at 1.97 x 10(6)/kg. The overall purity and recovery rate of the CD34+ cells were 72.2% and 65.0%, respectively. There were no severe adverse effects after PBSC transplantation, and the time required for recovery of neutrophils to over 0. 5 x 10(9)/l and platelets to over 50 x 10(9)/l was 11 and 21 days, respectively. Transplantation of CD34+ cells positively selected from cryopreserved PBSC provides engraftment ability similar to that of unmanipulated PBSC.

Antigens, CD34↗