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Biomedical subjects

K Sawada

Publications and source records attributed to K Sawada.

At least 127 records · Page 7Linked to original sources
PubMed1999

4-(1-benzoylindol-3-yl)butyric acids and FK143: novel nonsteroidal inhibitors of steroid 5 alpha-reductase (II).

A novel series of indolebutyric acids with varying benzoyl substituents were synthesized to develop nonsteroidal inhibitors of steroid 5 alpha-reductase. We previously reported the discovery of a novel nonsteroidal 5 alpha-reductase inhibitor, FR119680, which had an IC50 value of 5.0 nM against the rat prostatic enzyme. However, this compound was not strongly active against the human prostatic enzyme. By further study of the structure-activity relationships we succeeded in producing the strongly active compound, FK143, 4-[3-[3-[bis(4-isobutylphenyl)-methylamino]benzoyl]-1H-indol-1-yl] butyric acid, with an IC50 value of 1.9 nM against the human enzyme. FK143 also has in vivo inhibitory activity against the castrated young rat model and it should therefore be an extremely useful agent for the treatment of benign prostatic hyperplasia.

5-alpha Reductase Inhibitors↗
PubMed1999

Cloning and sequencing of a high-alkaline pectate lyase gene from an alkaliphilic Bacillus isolate.

Alkaliphilic Bacillus sp. strain KSM-P103 was found to exoproduce a high-alkaline pectate lyase (pectate transeliminase, EC 4.2.2.2). The gene for this enzyme from the alkaliphile was cloned and sequenced for the first time. The structural gene contained a 1,038-bp open reading frame encoding 345 amino acids. The deduced amino acid sequence of the mature enzyme (302 amino acids, 33,312 Da), designated Pel-103, showed very low similarity to those of known pectate lyases with 28-36% identity: the loop regions were very short and the amino acid usage in the parallel beta-helix core structure was considerably different. Moreover, physicochemical and catalytic properties of Pel-103 were different from those of other enzymes reported so far. Pel-103 was a very basic protein with an isoelectric point close to pH 10.5 and had optimal activity at 60-65 degrees C and at pH as high as 10.5. However, Pel-103 appeared to have a similar core and active site topology to the enzymes of known structure from Erwinia chrysanthemi and Bacillus subtilis. Expression of the gene for Pel-103 in B. subtilis resulted in high pectate lyase activity in the culture broth, concomitant with the appearance of a main protein band on an SDS gel at 33 kDa.

Alkalies↗
PubMed1999

Effect of leukocytapheresis therapy using a leukocyte removal filter in Crohn's disease.

Eighteen patients with active Crohn's disease were treated with one leukocytapheresis session per week for a five-week intensive therapy, decreasing to one leukocytapheresis session per month for five sessions of initial maintenance therapy. Nutritional indices, inflammatory reactions, flow cytometry profiles, and cytokine production were also assessed before and after the intensive and initial maintenance therapy. Nine of the patients (50%) attained remission at the end of the intensive therapy. The nine non-remission patients had exhibited longer periods of suffering and more severely affected sites prior to the therapy. In 14 of 18 patients (77.8%), the nutritional indices, Internal Organization of Inflammatory Bowel Disease (IOIBD) score and Crohn's Disease Activity Index (CDAI) improved from the pretherapy levels, but only the remission group (50%) showed improvement in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The remission group showed significantly higher pretherapy CD4+ CD45+ cell ratios and interleukin-2 (IL-2) production than the non-remission group, and significantly lower activated cells.

Adult↗
PubMed1999

[Mechanism of leukocytapheresis effect in the treatment of ulcerative colitis].

To solve adverse effects of high dose steroid administration for patients with moderately severe and severe ulcerative colitis (UC), additional use of leukocytapheresis (LCAP) was tried to settle colonic inflammation. We evaluated immunological changes in the treatment of LCAP using leukocyte removal filter for UC patients. We then assessed the clinical effectiveness of LCAP compared with that of high dose of steroid therapy. LCAP removed monocytes, granulocytes, and lymphocytes presenting CD 11 b+, CD 11 c+, and HLADR+, selectively from the patients. Proinflammatory cytokine productions measured such as TNF alpha, IL-1 beta, and IL 8 reduced and IL 10 increased immediately after LCAP compared with before perfusion. Improved rate was about 70% for LCAP group and about 40% for high dose steroid group (Refer J Gastroenterol). Selective removal of granulocyte, monocytes, and activated lymphocytes inhibits proinflammatory cytokine production and increases immune modulating cytokine productions (Refer Therapeutic Apheresis). Then quick inhibition of several inflammatory deteriorated factors simultaneously controls the activity and clinical symptoms of UC with less severe adverse effects. It can be considered one option for treatment of UC.

Adult↗
PubMed1999

A pilot study of a response oriented chemotherapeutic regimen combined with autologous peripheral blood progenitor cell transplantation in aggressive non-Hodgkin's lymphoma.

Fourteen consecutive patients with poor-risk aggressive NHL who at presentation had any one of four risk factors underwent response oriented induction chemotherapy and successive high-dose chemotherapy followed by autologous PBPC transplantation. After treatment with three cycles of conventional CHOP with G-CSF support (CHOP-G), the response was evaluated. For patients who achieved a complete remission (CR), an additional three cycles of CHOP-G were administered, while for partial response patients, another induction regimen including some non-cross-resistant agents was given; three cycles of VIPDexa-G (etoposide, ifosfamide, cisplatinum and dexamethasone) +/- two cycles of ENAP-G (mitoxantrone, etoposide, cytosine arabinoside and prednisone), were given. The scheduled induction chemotherapy, was followed by treatment with a high-dose cytoreductive regimen followed by autologous PBPC transplantation. After three cycles of CHOP-G, four patients (29%) achieved a CR, and 10 (71%) achieved a partial response (PR). When all scheduled induction therapy was completed, 10 patients (71%) had a CR. All 14 patients received high-dose therapy and obtained a complete hematologic recovery, except for one with a bone marrow relapse two months after transplantation. Evaluation of response after high-dose therapy showed 12 CRs (86%) which included three additional CRs, one PR, and one toxicity-related death. With a median follow-up of 12 months (range, 4 to 40), 12 are alive, with 11 in continuous first CR, and one relapse. The 2-year overall survival (OS) rate and event-free survival (EFS) rate are 77% and 79%, respectively, while the disease-free survival (DFS) rate is 92%. In conclusion, this pilot study suggests that response oriented induction chemotherapy and successive high-dose chemotherapy followed by autologous PBPC transplantation is commendable and can be associated with a high rate of remission and DFS for poor risk subjects with aggressive NHL.

Adolescent↗
PubMed1999

The first Japanese family with Sebastian platelet syndrome.

This report describes the first Japanese family diagnosed with Sebastian platelet syndrome. Within this family, a 6-year-old boy and 3 family members on his paternal side demonstrated thrombocytopenia with giant platelets and inclusion bodies in granulocytes, but the additional clinical features of Alport's syndrome occurring in the Fechtner syndrome were lacking. Light microscopy and ultrastructural findings of the leukocyte inclusion bodies distinguished these patients from the May-Hegglin anomaly. This family showed consistently higher levels of platelet-associated IgG (PAIgG), while surface expression of platelet membrane glycoproteins (GPIIb/IIIa and GPIb) and plasma glycocalicin levels were within the normal range. Careful observation of the giant platelet and leukocyte inclusion bodies in blood smears may help the diagnosis of this rare disease entity.

Adult↗
PubMed1999

[Breast cancer at the site of an implanted pacemaker].

We report here an 81-old-female patient who had a permanent pacemaker implanted in the right chest and who developed breast cancer near the site of the implanted generator. The cancer was diagnosed as stage I adenocarcinoma and radical mastectomy preserving pectoral muscles was indicated. During temporary pacing via the femoral approach, the pacemaker lead was transferred to the left subclavicular area crossing before the sternum and the generator was reimplanted in the left chest without use of lead extension kit. After reimplantation of the generator, radical mastectomy was performed. Clinical course was uneventful after the operation without infection or pacing failure. For the patient who needs surgical procedure in the site of implanted pacemaker generator, this technique of reimplantation is one of the useful choices.

Adenocarcinoma↗
PubMed1999

[(A report of the Citizen Joint Symposium by the Hokkaido Medical Society) cancer--how to inform].

The Citizen Joint Symposium on "Cancer--How to Inform" was held by the Hokkaido Medical Society at Hokkaido University Conference Hall on November 11, 1998. Five speakers, including a medical doctor, a nurse, a member of a patient's family, a medical student and a nursing student, presented their experiences and opinions from their own point of view. Dr. F. Takenaka, a medical doctor who had overcome his serious condition as a patient with cancer, also gave a talk on "The Choice of the Doctor Suffered from Cancer." The aim of this symposium was to consider how to support the quality of life of patients with cancer and how the informed consent to be. The opinions from the citizen were collected by the unregistered questionnaire. One of the speakers proposed the objective assessment on the acceptance of the patients. The most concerned for the participants was how to decide the timing and the way to inform each patient with cancer of their disease and condition.

Humans↗
PubMed1999

Recognition of L-amino acid ester compounds by rat peptide transporters PEPT1 and PEPT2.

Peptide transporters (PEPT1 and PEPT2) in epithelia play an important role in the absorption of small peptides and peptide-like drugs. Recently, it was demonstrated that various nonpeptidic compounds can be transported by these transporters. In the present study, we focused on the L-amino acid ester compounds and examined the mechanisms of their interaction with rat PEPTs (rPEPTs) using stable transfectants. Valacyclovir, the L-valyl ester prodrug of the antiherpetic agent acyclovir, competitively inhibited [(14)C]glycylsarcosine uptake in the rPEPT1- or rPEPT2-expressing cells. Dixon plot analyses showed that the inhibition constant (K(i)) values of valacyclovir were 2.7 and 0.22 mM for rPEPT1 and rPEPT2, respectively, suggesting that rPEPT2 had higher affinity for this agent. Various L-valine alkyl esters significantly inhibited [(14)C]glycylsarcosine uptake. L-Valine methyl ester (Val-OMe) competitively inhibited [(14)C]glycylsarcosine uptake with K(i) values of 3.6 and 0.83 mM for rPEPT1 and rPEPT2, respectively, indicating that Val-OMe is also a high-affinity substrate for rPEPT2. Val-OMe had a trans-stimulation effect on [(14)C]glycylsarcosine efflux from both transfectants, suggesting the translocation of L-valine methyl ester via rPEPTs. Val-OMe showed the most potent inhibitory effect among the several L-amino acid methyl esters examined. We conclude that Val-OMe, as well as valacyclovir, could be recognized and transported by rPEPT1 and rPEPT2 and that these L-valyl esters showed higher affinity for rPEPT2 as do most substrates of these transporters. Our results suggest that L-valine is a desirable L-amino acid for the esterification of poorly permeable drugs to enhance their oral bioavailability targeting intestinal PEPT1.

Acyclovir↗
PubMed1999

[Leukocytapheresis for ulcerative colitis].

Leukocytapheresis(LCAP) and Granulocytapheresis(GCAP) are classified as extracorporeal circulation therapy(ECCT). These therapies are a novel, effective way to treat patients with ulcerative colitis(UC). During 7 weeks of intensive therapy(LCAP weekly, predonisolone(PSL) 30-80 mg/day), UC patients treated with LCAP revealed significant improvements on their subjective and objective symptoms compared to patients treated with PSL intravenous administration. Moreover, LCAP has been recognized as safer than other drugs for UC. In our previous study, only 9.9% out of 1,978 LCAP sessions showed some side effects, and most were mild and temporary. Therefore, LCAP could be the first choice to treat UC patients who resist and/or reveal severe complications against ordinary drug therapies.

Adolescent↗
PubMed1999

Fate maps of the primitive streak in chick and quail embryo: ingression timing of progenitor cells of each rostro-caudal axial level of somites.

Developmental fates of cells emigrating from the primitive streak were traced by a fluorescent dye Dil both in chick and in quail embryos from the fully grown streak stage to 12-somite stage, focusing on the development of mesoderm and especially on the timing of ingression of each level of somitic mesoderm. The fate maps of the chick and quail streak were alike, although the chick streak was longer at all stages examined. The anterior part of the primitive streak predominantly produced somites. The thoracic and the lumbar somites were shown to begin to ingress at the 5 somite-stage and 10 somite-stage in a chick embryo, and 6 somite-stage and 9 somite-stage in a quail embryo, respectively. The posterior part of the streak served mainly as the origin of more lateral or extra embryonic mesoderm. As development proceeded, the fate of the posterior part of the streak changed from the lateral plate mesoderm to the tail bud mesoderm and then to extra embryonic, allantois mesoderm. The fate map of the primitive streak in chick and quail embryo presented here will serve as basic data for studies on mesoderm development with embryo manipulation, especially for transplantation experiments between chick and quail embryos.

Animals↗
PubMed1998

Single tottering mutations responsible for the neuropathic phenotype of the P-type calcium channel.

Recent genetic and molecular biological analyses have revealed many forms of inherited channelopathies. Homozygous ataxic mice, tottering (tg) and leaner (tgla) mice, have mutations in the P/Q-type Ca2+ channel alpha1A subunit gene. Although their clinical phenotypes, histological changes, and locations of gene mutations are known, it remains unclear what phenotypes the mutant Ca2+ channels manifest, or whether the altered channel properties are the primary consequence of the mutations. To address these questions, we have characterized the electrophysiological properties of Ca2+ channels in cerebellar Purkinje cells, where the P-type is the dominant Ca2+ channel, dissociated from the normal, tg, and tgla mice, and compared them with the properties of the wild-type and mutant alpha1A channels recombinantly expressed with the alpha2 and beta subunits in baby hamster kidney cells. The most striking feature of Ca2+ channel currents of mutant Purkinje cells was a marked reduction in current density, being reduced to approximately 60 and approximately 40% of control in tg and tgla mice, respectively, without changes of cell size. The Ca2+ channel currents in the tg Purkinje cells showed a relative increase in non-inactivating component in voltage-dependent inactivation. Besides the same change, those of the tgla mice showed a more distinct change in voltage dependence of activation and inactivation, being shifted in the depolarizing direction by approximately 10 mV, with a broader voltage dependence of inactivation. In the recombinant expression system, the tg channel with a missense mutation (P601L) and one form of the two possible tgla aberrant splicing products, tgla (short) channel, showed a significant reduction in current density, while the other form of the tgla channels, tgla (long), had a current density comparable to the normal control. On the other hand, the shift in voltage dependence of activation and inactivation was observed only for the tgla (long) channel. Comparison of properties of the native and recombinant mutant channels suggests that single tottering mutations are directly responsible for the neuropathic phenotypes of reduction in current density and deviations in gating behavior, which lead to neuronal death and cerebellar atrophy.

Animals↗
PubMed1998

Lysosomal glycogen storage disease with normal acid maltase with early fatal outcome.

In a male infant who had cardiomyopathy, generalized muscle weakness and increased serum creatine kinase levels, his muscle biopsy revealed myopathic changes with tiny intracytoplasmic vacuoles containing PAS-positive material and high acid phosphatase activity, but had normal acid maltase activity biochemically. These findings were consistent with those seen in lysosomal glycogen storage disease with normal acid maltase (Danon disease). Sarcolemmal indentations commonly seen in this disease were missing, but a complement membrane attack complex, C5b-9 was positive along the surface membrane of the muscle fibers as seen in X-linked vacuolar myopathy. The patient was on a respirator and died at 27 months of age from pneumonia and hypertrophic cardiomyopathy. Lysosomal glycogen storage disease with normal acid maltase may be manifested at birth with marked skeletal and cardiac involvement leading to death in early infancy.

Biomarkers↗
PubMed1998

Different adhesive characteristics and VLA-4 expression of CD34(+) progenitors in G0/G1 versus S+G2/M phases of the cell cycle.

We identified the cell cycle status of CD34(+) cells of steady-state bone marrow (BM) and peripheral blood (PB) obtained from healthy volunteers, and those of apherasis PB samples collected from healthy donors who had been administered granulocyte colony-stimulating factor (G-CSF). More than 10% of CD34(+) cells in BM were in S+G2/M phase. In contrast, regardless of whether G-CSF treatment was performed, less than 2% of CD34(+) cells in PB were cycling. BM CD34(+) cells showed greater VLA-4 expression and adherence to stromal cells than PB CD34(+) cells. In addition, when cycling and dormant BM CD34(+) cells were analyzed separately, the cells in S+G2/M phase expressed more VLA-4 and adhered to the stromal cell monolayer more efficiently than the cells in G0/G1 phase. Furthermore, this adhesion of CD34(+) cells to the stromal cell layer was almost completely inhibited by anti-VLA-4 antibody. Taken together, these results suggest that CD34(+) progenitors in G0/G1 phase of the cell cycle differ from those in S+G2/M phase in adhesiveness mediated by VLA-4 in the hematopoietic microenvironment.

Adult↗
PubMed1998

Erythropoietin induces tyrosine phosphorylation of Jak2, STAT5A, and STAT5B in primary cultured human erythroid precursors.

We examined signaling by erythropoietin in highly purified human colony forming unit-erythroid cells, generated in vitro from CD34(+) cells. We found that erythropoietin induces tyrosine phosphorylation of Jak2, STAT5A, and STAT5B. Tyrosine phosphorylation of Jak2 reaches a peak around 10 minutes after stimulation and is maximum at 5 U/mL of erythropoietin. Tyrosine phosphorylation of STAT5 is accompanied by the translocation of activated STAT5 to the nucleus as shown by electrophoretic mobility shift assay (EMSA) using 32Pi-labeled STAT5 binding site in the beta-casein promoter. Tyrosine phosphorylation STAT1 or STAT3 was not detected in human erythroid precursors after stimulation with erythropoietin. Crkl, an SH2/SH3 adapter protein, becomes coimmunoprecipitated specifically with STAT5 from erythropoietin-stimulated erythroid cells; although it was shown to become associated with c-Cbl in the studies using cell lines. Thus, human erythroid precursors can be expanded in vitro in sufficient numbers and purity to allow its usage in signal transduction studies. This report sets a basis for further studies on signaling in primary cultured human erythroid precursors, which in turn contribute to our better understanding in the differentiation processes of erythrocytes and their precursors.

Cells, Cultured↗
PubMed1998

Reconstitution of F1-ATPase activity from Escherichia coli subunits alpha, beta and subunit gamma tagged with six histidine residues at the C-terminus.

An engineered gamma subunit of Escherichia coli F1-ATPase with extra 14 and 20 amino acid residues at the N- and C-termini (His-tag gamma), respectively, was overproduced in E. coli and purified. Six histidines are included in the C-terminal extension. The reconstituted F1 containing alpha, beta, and His-tagged gamma exhibited sixty percent of the wild-type ATPase activity. The reconstituted alphabeta His-tag gamma complex was subjected to affinity chromatography with nickel-nitrilotriacetic acid (Ni-NTA) agarose resin. ATPase activity was eluted specifically with imidazole. These results implied that the tag sequence protruded to the surface of the complex and did not seriously impair the activity. The reconstituted alphabeta His-tag gamma complex, even after its binding to the resin, exhibited ATPase activity suggesting that the gamma subunit, when fixed to a solid phase, may rotate the alphabeta complex. This system may provide a new approach for analysis of the rotation mechanisms in F1-ATPase.

Bacterial Proteins↗