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Biomedical subjects

K Namba

Publications and source records attributed to K Namba.

At least 91 records · Page 5Linked to original sources

New selective media for isolation of clostridia from faecal specimens.

Two selective media, novobiocin-colistin agar (NCA) and colistin-crystal violet agar (CCA), were developed for isolating clostridia from human and animal faeces. The basal medium was modified Eggerth-Gagnon agar. The NCA medium contains novobiocin (8 micrograms ml-1) and colistin (8 micrograms ml-1) and the CCA medium contains colistin (10 micrograms ml-1) and crystal violet (10 micrograms ml-1). Nine faecal specimens were cultured. Clostridia isolated on these media were similar to those on non-selective media, and higher than those isolated after heat treatment. However, more clostridial species were isolated on the new selective media compared with the non-selective medium. These selective agars were particularly useful for enumerating and isolating clostridia from human faeces.

Animals↗

Hypotensive effects of a new transdermal delivery system for clonidine (M-5041T) in spontaneously and renal hypertensive rats.

1. Antihypertensive effects of a new transdermal delivery system for clonidine (clonidine tape; M-50417) were investigated in spontaneously hypertensive rats (SHR), 2-kidney, 1-clip renal hypertensive rats (RHR) and deoxycorticosterone acetate/salt (DOCA/Salt) hypertensive rats. 2. M-5041T (0.5-4.5 mg/kg) elicited long-lasting hypotensive effects and bradycardia in a dose-dependent manner during 24 h patching in three hypertensive models compared with oral clonidine (100 mu g/kg). 3. The most hypotensive effect of M-5041T was observed in DOCA/salt hypertensive rats. 4. Co-administration of M-5041T with either trichloromethiazide (1 mg/kg, orally) or nifedipine (3 mg/kg, orally) at each dose without hypotensive effects per se induced significant hypotension in SHR. 5. Repeated administrations of M-5041T (1.5 mg/kg per day) for a consecutive 7 days produced significant hypotensive effects at postpatching 6 h, and recovered a postpatching 24 h in SHR. 6. Repetitive M-5041T administrations displayed no tolerance on the hypotensive effects and were devoid of any withdrawal syndrome. 7. These findings suggest that M-5041T may serve as an efficiently useful antihypertensive transdermal delivery system in humans.

Administration, Cutaneous↗

Inhibitory action of indomethacin on neutrophil infiltration in monosodium urate-induced pleurisy in rats.

The effects of indomethacin on the production of cytokines at inflammatory sites were investigated in the monosodium urate (MSU) pleurisy model characterized by both cellular influx and edema. Indomethacin (10 mg/kg) orally administered 0.5 hr prior to MSU injection into the pleural cavity significantly inhibited MSU-induced neutrophil accumulation in the cavity. In addition, the drug slightly enhanced the level of MSU-induced tumor necrosis factor production without affecting interleukin-1 production. Furthermore, indomethacin inhibited both the levels of MSU-induced rat cytokine-induced neutrophil chemoattractant (CINC/gro) and interleukin-6 (IL-6) production by 78.3% at 3 hr and 45.8% at 4 hr post-injection, respectively. Although intrapleural injection of CINC/gro induced neutrophil infiltration in a dose-dependent manner, IL-6 did not affect the action of CINC/gro on neutrophil influx. These findings suggest that the inhibitory action of indomethacin on neutrophil infiltration is, at least, partly mediated by a decrease in the MSU-induced CINC/gro content in this model.

Administration, Oral↗

Recommended procedures for the classification of acute leukaemias.

The classification of acute leukaemias is now widely based on a combined morphological, cytochemical and immunophenotyping approach. Difficulties are frequently encountered however in reaching an acceptable degree of diagnostic concordance between different laboratories because of variations in the techniques used (in terms of methodologies, reagents and equipment) and diagnostic interpretation. The International Council for Standardization in Haematology (ICSH) convened an expert panel to consider currently available diagnostic techniques with the aim of defining a minimum cytochemical and immunological diagnostic panel that could be used as core components for the classification of acute leukaemia. The proposed ICSH scheme, which attempts to balance the basic requirement for providing precise and informative diagnostic information without limiting its use to only those laboratories with sophisticated facilities, is based on three sequential levels of investigation; primary cytochemistry, intracellular phenotyping and membrane immunophenotyping. The minimum ICSH recommended cytochemistries comprise myeloperoxidase (MPO), chloroacetate esterase (ChlorE) and alpha-naphthyl acetate esterase (ANAE), and standardised methods for these cytochemistries are detailed in this communication. For cases of acute leukaemia that remain unclassified by primary cytochemistry, subsequent immunological analyses for cytoplasmic CD3, CD22, MPO and nuclear TdT are recommended. The ICSH panel considers that the use of these minimum primary cytochemical and intracellular phenotyping procedures will lead to the consistent classification of most acute leukaemias, and that the third level of investigation (membrane immunophenotyping) should be used for the purposes of confirmation, diagnostic clarification of atypical leukaemias, and the subtyping of acute lymphoblastic leukaemias (ALL). The ICSH panel also recognised that there are a number of additional technologies which can provide definitive diagnostic information, such as cytogenetics and DNA genotyping, but these were excluded from the minimum panel because of their restricted availability. While many specialised laboratories, particularly in the areas of diagnostic research, will continue to use individual investigatory protocols, it is considered that the inclusion of the ICSH scheme as core components would lead to greater consistency when comparing independent studies of acute leukaemia.

Acute Disease↗

Structure-function relationship of the xylanase from alkaliphilic Bacillus sp. strain 41M-1.

Xylanase J from alkaliphilic Bacillus sp. strain 41M-1 contains a family G catalytic domain at the N-terminus, followed by a linker sequence and a functionally-unknown C-terminal domain. The mutational analysis of xylanase J indicated that Glu-93, Glu-183, Trp-18, Trp-86, Tyr-84 and Tyr-95 play an important role in the catalytic activity. A deletion derivative of xylanase J lacking the C-terminal domain retained its activity, suggesting that the C-terminal domain does not directly involved in catalysis.

Amino Acid Sequence↗

Enhancement of platelet recovery in X-irradiated guinea pigs by romurtide, a synthetic muramyl dipeptide derivative.

The response of megakaryocytes and platelets to the administration of romurtide, a synthetic muramyl dipeptide derivative, was investigated in normal and irradiated guinea pigs. Romurtide was administered subcutaneously in a single dose or daily doses at levels of 1 to 100 micrograms/animal/day to normal animals to assess the dose response. Subsequently, dosage at 100 micrograms/animal/d for 8 consecutive days was initiated in separate groups of animals immediately after 1 Gy total body x-irradiation. In normal animals, a significant dose-dependent increase in the platelet count was noted, and a prolonged thrombocytopoiesis was detectable from 7 through 15 days after the initiation of romurtide administered for 8 days at a dose of 100 micrograms/animal/d. A significant increase in the white blood cell (WBC) count was also observed during days 1 through 11 after beginning romurtide treatment. In the irradiated animals, the treatment with romurtide increased platelet counts during the recovery phase of thrombocytopenia, thus apparently decreasing the time required for recovery to a normal platelet level. Before the rapid recovery of platelet counts by romurtide treatment, a marked increase in the number of megakaryocytes was noted as early as 7 days after irradiation. This increase was accompanied by an accelerated shift of the size distribution of megakaryocytes toward larger size class. Thus, the mean megakaryocyte size was significantly greater in guinea pigs receiving romurtide than in controls. Preceding the increase in the number of megakaryocytes, the serum interleukin-6 levels were found to be approximately 5 times greater than those in control animals. Treatment with romurtide diminished the WBC count nadir, resulting in significantly higher WBC count levels than in controls. Elevation of the plasma fibrinogen level was observed in the treated animals, and normalized gradually after discontinuation of romurtide treatment. These results indicate a possible therapeutic potential of romurtide in the management of thrombocytopenia associated with myelosuppression.

Acetylmuramyl-Alanyl-Isoglutamine↗

Relationship between hypotensive effects and plasma concentrations of clonidine in spontaneously hypertensive rats: continuous treatment and sudden termination of clonidine infusion.

1. Clonidine was administered subcutaneously (62.5, 125 and 250 micrograms/kg/day) for 8 days using an osmotic infusion pump in spontaneously hypertensive rats (SHR). Clonidine, administered at 125 and 250 micrograms/kg/day at 48 hr after infusion, respectively, and thereafter were maintained at this level throughout the infusion period. 3. After terminating clonidine infusion, a rapid drug elimination from the plasma was manifested in both groups (125 and 250 micrograms/kg/day) with plasma clonidine levels, resulting in a decrease below 0.5 ng/ml at 4 and 6 hr, respectively. Four hours after terminating clonidine infusion at 125 and 250 micrograms/kg/day, transient but not remarkable increases in blood pressure and heart rate were observed only in the latter group compared with the values before termination. 4. These findings reveal that marked hypotensive effects were induced by relatively high doses (125 and 250 micrograms/kg/day) of clonidine in SHR, but no remarkable withdrawal symptoms after termination of clonidine infusion were observed. Therefore, unwanted withdrawal symptoms probably occur when an extremely high dose (250 micrograms/kg/day or more) of clonidine was infused for a long period (8 days or more) in SHR.

Animals↗

[Development of a new delayed healing model of an open skin wound and effects of M-1011G (ointment gauze containing 5% lysozyme hydrochloride) on the model].

We tried to develop a new delayed healing model of an open wound made on the dorsal skin of a rat by inducing malnutrition with restriction of food intake. We determined the effects of a newly introduced ointment gauze containing 5% lysozyme hydrochloride (M-1011G) on this model. Malnutrition characterized by a decrease in body weight and serum protein was produced by restricting the daily intake of commercially available food to 6 g for 2 weeks without liver disturbance and thereafter maintained with food intake of 12 g/day. Under these conditions, healing of the open wound made on the dorsal skin was prolonged, as compared with that of the wound made on a well-nourished animal. In this model, statistical studies showed that M-1011G was the most effective in accelerating the reduction of the wound area and shortening of the time required for the complete healing, among the following treatments: sterilized gauze alone, ointment gauze alone and 5% lysozyme hydrochloride-containing emulsified ointment. Histological findings showed that M-1011G greatly accelerated the granulation of this tissue which is essential for wound healing, probably due to stimulation of epidermization and regenerated granulation in the wound.

Animals↗

Recommended procedures for the classification of acute leukaemias. International Council for Standardization in Haematology (ICSH).

The classification of acute leukaemias is now widely based on a combined morphological, cytochemical and immunophenotyping approach. Difficulties are frequently encountered however in reaching an acceptable degree of diagnostic concordance between different laboratories because of variations in the techniques used (in terms of methodologies, reagents and equipment) and diagnostic interpretation. The International Council for Standardization in Haematology (ICSH) convened an expert panel to consider currently available diagnostic techniques with the aim of defining a minimum cytochemical and immunological diagnostic panel that could be used as core components for the classification of acute leukemia. The proposed ICSH scheme, which attempts to balance the basic requirement for providing precise and informative diagnostic information without limiting its use to only those laboratories with sophisticated facilities, is based on three sequential levels of investigation; primary cytochemistry, intracellular phenotyping and membrane immunophenotyping. The minimum ICSH recommended cytochemistries comprise myeloperoxidase (MPO), chloroacetate esterase (ChlorE) and alpha-naphthyl acetate esterase (ANAE), and standardised methods for these cytochemistries are detailed in this communication. For cases of acute leukaemia that remain unclassified by primary cytochemistry, subsequent immunological analyses for cytoplasmic CD3, CD22, MPO and nuclear TdT are recommended. The ICSH panel considers that the use of these minimum primary cytochemical and intracellular phenotyping procedures will lead to the consistent classification of most acute leukaemias, and that the third level of investigation (membrane immunophenotyping) should be used for the purposes of confirmation, diagnostic clarification of atypical leukaemias, and the subtyping of acute lymphoblastic leukaemias (ALL). The ICSH panel also recognised that there are a number of additional technologies which can provide definitive diagnostic information, such as cytogenetics and DNA genotyping, but these were excluded from the minimum panel because of their restricted availability. While many specialised laboratories, particularly in the areas of diagnostic research, will continue to use individual investigatory protocols, it is considered that the inclusion of the ICSH scheme as core components would lead to greater consistency when comparing independent studies of acute leukemia.

Acute Disease↗

Morphological pathway of flagellar assembly in Salmonella typhimurium.

The process of flagellar assembly was investigated in Salmonella typhimurium. Seven types of flagellar precursors produced by various flagellar mutants were purified by CsCl density gradient protocol. They were characterized morphologically by electron microscopy, and biochemically by two-dimensional gel electrophoresis. The MS ring is formed in the absence of any other flagellar components, including the switch complex and the putative export apparatus. Four proteins previously identified as rod components, FlgB, FlgC, FlgF, FlgG, and another protein, FliE, assemble co-operatively into a stable structure. The hook is formed in two distinct steps; formation of its proximal part and elongation. Proximal part formation occurs, but elongation does not occur, in the absence of the LP ring. FlgD is necessary for hook formation, but not for LP-ring formation. A revised pathway of flagellar assembly is proposed based on these and other results.

Bacterial Proteins↗

Conformational adaptability of the terminal regions of flagellin.

Secondary structure formation in the disordered terminal regions of flagellin were studied by circular dichroic (CD) spectroscopy, Fourier transform infrared spectroscopy, and x-ray diffraction. The terminal regions of flagellin are known to form alpha-helical bundles upon polymerization into flagellar filaments. We found from comparative CD studies of flagellin and its F40 tryptic fragment that a highly alpha-helical conformation can be induced and stabilized in the terminal regions in 2,2,2-trifluoroethanol (TFE) containing solutions, which is known to promote intra-molecular hydrogen bonding. Two oligopeptides, N(37-61) and C(470-494), each corresponding to a portion of terminal regions and predicted to have a high alpha-helix forming potential, were synthesized and studied. Both peptides were disordered in an aqueous environment, but they showed a strong tendency to assume alpha-helical structure in solutions containing TFE. On the other hand, peptides were found to form transparent gels at high concentrations (> 15 mg/ml) and all three methods confirmed that the peptides become ordered into a predominantly beta structure upon gel formation. Our results show that large segments of the disordered terminal regions of flagellin can adopt alpha-helical as well as beta structure depending on the environmental conditions. This high degree of conformational adaptability may be reflecting some unique characteristics of the flagellin termini, which are involved in self-assembly and polymorphism of flagellar filament.

Biophysical Phenomena↗

Synergistic effect of romurtide with ampicillin against pneumococcal pneumonia in mice.

The anti-infective activity of romurtide, a synthetic muramyl dipeptide (MDP) derivative, was evaluated in experimental pneumococcal pneumonia in mice deficient in the third component of complement (C3). The compound was found to be effective against the pneumonia in combination with subcutaneous ampicillin (ABPC). This synergistic effect of romurtide with ABPC was most pronounced when the compound was administered subcutaneously 1 day before infection. Romurtide alone, however, was not effective, irrespective of its treatment timing. Similarly, consecutive treatment with ABPC alone failed to kill pneumococci in the lungs completely, and resultant regrowth of the organisms provoked purulent pneumonia. In contrast, the combination treatment of romurtide with ABPC successfully prevented most of the mice from the purulent pneumonia: the initial infiltration of resident alveolar macrophages and subsequent accumulation of macrophages were observed in the pneumonic foci. In accordance with the occurrence of these cellular responses in the lungs, pneumococci were successfully eliminated from the lungs in mice treated with romurtide in combination with ABPC. Thus, romurtide was suggested to promote recovery of the mice with pneumococcal pneumonia by activating resident and accumulated macrophages in the pneumonic foci to eliminate pneumococci from the lung.

Acetylmuramyl-Alanyl-Isoglutamine↗

[Effect of SL-1010 (sodium hyaluronate with high molecular weight) on experimental osteoarthritis induced by intra-articularly applied papain in rabbits].

Sodium hyaluronate (HA) with a molecular weight of approximately 600,000-1,200,000 is reportedly effective against osteoarthritis (OA). However, since HA with higher molecular weight is expected to be more effective against OA, we investigated the effects of HA (SL-1010) newly produced by fermentation with a molecular weight of 1,800,000-2,100,000 on the experimental OA induced by intraarticular injection of papain, into the knee joint of the rabbit, in comparison with those of HA with a molecular weight of about 950,000 (HA-95). When 0.4, 0.8, and 1.6% papain (0.5ml) was injected into the knee joint of the animal twice with a 3-day interval, there were dose-dependent degenerative changes and a decrease in sulfated glycosaminoglycan (S-GAG) in the articular cartilage with slight synovial inflammatory changes 6 weeks after the final injection of papain. In this OA model, intraarticular application of SL-1010 slightly reduced the degeneration of articular cartilage, compared with the injections of HA-95 or saline (control). SL-1010 also caused a significant recovery in the S-GAG level which was decreased in the cartilage of the OA model, compared with the control. In addition, SL-1010 inhibited the release of 35S-GAG from the cartilage obtained from normal and OA model joints. These results suggest that SL-1010 is effective in inhibiting the degeneration of cartilage in the OA model, probably due to the recovery of the S-GAG level by reducing the release of S-GAG from the cartilage.

Animals↗

[Effects of SL-1010 (sodium hyaluronate with high molecular weight) on experimental osteoarthritis induced by intra-articularly applied papain in guinea pigs].

Effects of SL-1010 on the experimental osteoarthritis (OA) produced by intra-articular injection of papain, proteolytic enzyme, in the knee joint of the guinea pigs were histologically and biochemically investigated. In addition, experimental conditions to produce OA in guinea pig knee joint were also examined, since papain-induced OA has been mainly studied in rabbits. Six weeks after intra-articular injection of papain (1%, 0.1 ml), there were inflammatory reactions of the synovial membrane, degenerative changes in chondrocytes and the matrix of the articular cartilage, a decrease in the Safranin-O staining intensity and lowering of sulfated glycosaminoglycan. Electronmicroscopic observations revealed that the amorphous layer had disappeared and large bundles of unit collagen fibers and larger collagen fibers had appeared in the cartilage matrix. In the OA model, SL-1010 reduced the inflammatory reactions of the synovial membrane, inhibited development of degenerative changes in chondrocytes and the matrix of the articular cartilage and recovered the Safranin-O staining intensity. The sulfated glycosaminoglycan contents in the cartilage was significantly increased in the SL-1010-treated group, compared with the control group. The electromicroscopically observed charges in the papain-injected knee joint of the control group were rarely detected in the SL-1010-treated group. These results suggest that SL-1010 inhibits degenerative changes in the chondrocytes and the matrix probably by reducing synovial inflammation and protection of the cartilage in the OA model of guinea pigs.

Animals↗

Effect of taurine concentration on platelet aggregation in gestosis patients with edema, proteinuria and hypertension.

To elucidate the relationship between the high concentration of taurine in platelets and platelet aggregation in patients with EPH gestosis (gestosis with edema, proteinuria and hypertension), platelet aggregation and the platelet release response (release of ATP and beta-thromboglobulin) were studied in the washed platelet suspension (PS) obtained from normal pregnant or non-pregnant women and EPH gestosis patients. Platelet aggregation and platelet release response were significantly lower in EPH gestosis patients than in normal pregnant and non-pregnant women. Platelet aggregation, platelet release response induced by ADP and collagen and the aggregation induced by A23187 were inhibited in taurine-loaded PS from non-pregnant women. These results suggest that the decrease of platelet aggregation in EPH gestosis patients was caused by high concentrations of taurine in platelets, which may inhibit the intracellular Ca2+ movement and platelet release response. Therefore, taurine appears to have a protective effect against the hyper-coagulative state in EPH gestosis.

Adenosine Diphosphate↗

Multiple space-occupying lesions of the spleen in a case of Gaucher's disease.

A 50-year-old female patient was admitted because of an enormously enlarged spleen and thrombocytopenia. Ultrasonography and magnetic resonance imaging revealed multiple space-occupying lesions in the spleen. She was diagnosed as having Gaucher's disease based on the low level of beta-glucosidase activity in leukocytes and Gaucher's cells present in bone marrow aspirate. Severe hypersplenism necessitated splenectomy. Pathological studies of the excised spleen, including ultrastructural examinations, demonstrated that multiple space-occupying lesions in the spleen were composed of typical Gaucher cells.

Female↗

Effects of hypoxia on renal function in carp, Cyprinus carpio.

1. Changes in urine and blood properties and heart rate (HR) of carp were investigated during and following hypoxia. 2. When carp were exposed to hypoxic conditions, urine flow in some carp increased immediately. However, it decreased gradually with time. Osmotic pressure and Na+, Cl-, Ca2+ and Mg2+ levels in urine increased in contrast to urine flow. K+, P, ammonium, and lactic acid levels in urine increased gradually. 3. When carp lost their balance, blood pH and plasma K+ were lower, and RBC, Ht, Hb, Mg2+, P, ammonium, lactic acid, and glucose in plasma were higher than those of the control. 4. As water-dissolved oxygen level was restored, urine flow increased immediately and soon decreased to the control rate. Other urine properties showed higher values than the initial levels and decreased with time. No significant change was found in urinary protein. 5. The relationship between HR and urine flow is discussed.

Animals↗