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Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 343 records · Page 19Linked to original sources
PubMed1989

Decreased activity of cytochrome c oxidase in the macular mottled mouse: an immuno-electron microscopic study.

The macular mottled mouse is a murine model of the kinky hair syndrome, characterized by a deficiency in copper transport. Cytochrome c oxidase (CCO), a respiratory enzyme, is located in the inner mitochondrial membrane and consists of seven subunits, along with copper and iron. Biochemical and histochemical findings indicated that CCO activity was decreased in the cerebellum of the macular mottled mice but not in that of the controls. Immunocytochemical analysis, using anti-CCO and anti-complex III rabbit sera, revealed that CCO in the macular mottled mice was stained more weakly than that in the controls. Immuno-electron microscopic examination of CCO and complex III, using a method of gold labeling, was also performed. In the control mice, a high concentration of gold particles present over CCO and complex III could be seen in the inner mitochondrial membrane. The number of CCO-labeled gold particles was remarkably less, however, in the macular mottled mice, while no significant difference was found in the labeling of complex III between the two groups. It may be concluded that the very low CCO enzyme content in the macular mottled mouse results not only from a copper transport disorder but also from a CCO protein synthesis disorder which impairs the localization of CCO protein in the cerebellum.

Animals↗
PubMed1989

A simple method for observation of phagocytosis on bacterial thin-layer.

A simple method was developed to visually present the phagocytic activity of leukocytes by using adherent Staphylococcus aureus cells and blood applied on a plastic dish. When heparinized blood was applied on thin-layer of heat-killed S. aureus cells on the plastic dish, plaques due to the phagocytic activity of leukocytes were observed with a microscope under a low magnification. Fewer and smaller plaques were observed when plasma-deprived rather than whole blood was used. Some analyses were made in respect to the fundamental conditions required for optimal results. This method was considered to be useful for conveniently evaluating the serum opsonin activities and phagocytic function of leukocytes in various kinds of diseases.

Antigens, Bacterial↗
PubMed1989

Simple method for quantitation of cell-bound protein A on Staphylococcus aureus cells by means of hemagglutination with sheep erythrocytes differentially sensitized with rabbit antibody and its clinical application.

A simple method for quantitation of cell-bound protein A (SpA) on organisms of Staphylococcus aureus was successfully devised by using hemagglutination between staphylococcal organisms and a series of sheep erythrocyte suspensions sensitized with different amounts of anti sheep erythrocyte rabbit antiserum. The validity of the principle and the reproducibility of the method presented here were precisely analyzed and the details of the method are presented. The hemagglutination was quantitatively inhibited both by normal rabbit serum and by soluble SpA. Using the method presented here, 376 strains of S. aureus freshly isolated from clinical materials were subjected to SpA quantitation in cell-bound form. According to the results, there was an unexpected distribution profile in the amounts of cell-bound SpA among the clinical isolates, which showed a two-peak pattern. A possible usefulness of the method presented here in clinical investigations is briefly discussed also.

Animals↗
PubMed1989

Improved methods for detection and serotyping of coagulase from Staphylococcus aureus.

Improved methods for detection and serotyping of staphylocoagulase were concomitantly devised. We devised an improved method for detection of coagulase activity on agarose film in the same manner as single radial immunodiffusion. The amounts of reagents required for detection of coagulase on agarose film were successfully diminished by adding polyethylene glycol (PEG) to the original formula described by Boothby et al. Using microplates in another improved method for coagulase serotyping, the amount of reaction fluid required was considerably less compared with the conventional tube method. PEG was found to be also effective to increase the efficacy of coagulase serotyping. In the presence or absence of anti-coagulase antisera, culture supernatants of staphylococcal strain grown in brain heart infusion broth were incubated with the reaction fluid containing bovine fibrinogen, rabbit plasma, 6-amino caproic acid, polyethylene glycol 6,000. Coagulase activity was visualized as a turbid mass formed in the wells. Turbid mass formation due to coagulase activity was type-specifically inhibited in the presence of type-specific antisera. Detailed procedures of the methods are precisely described with some preliminary results obtained by the methods.

Coagulase↗
PubMed1989

Altered virulence of a pleiotropic Staphylococcus aureus mutant with a low producibility of coagulase and other factors in mice.

The virulence of a pleiotropic Staphylococcus aureus mutant with an extremely low producibility of coagulase and other factors was investigated in mouse. A mutant strain, designated as CL-1, showed the same LD50 and the same intrarenal proliferation as its parental strain, when the mutant organisms were inoculated in mice in high doses. The mutant organisms, however, showed a diminished intrarenal proliferation compared with its parental organisms in low doses. This mutant strain expressed a pleiotropic phenotype such as a concomitant reduction in the producibility of coagulase, alpha-toxin, and Panton-Valentine leucocidin. The total effect due to the reduction in producibility of various factors on the virulence of the mutant strain was investigated with studies on the bacterial resistance to the phagocytic activity of leucocytes. A possible role of coagulase and that of some other staphylococcal exoproteins in the pathogenesis of S. aureus were discussed.

Animals↗
PubMed1989

Variability of cortisol and adrenocorticotropic hormone responses to metoclopramide during the menstrual cycle.

Responses of cortisol and adrenocorticotropic hormone (ACTH) to metoclopramide (MCP) were examined in normal women throughout the menstrual cycle. The administration of MCP increased circulating levels of cortisol and ACTH in normal women during the mid-luteal but not during the early and late follicular phases. MCP may stimulate ACTH release through an antidopaminergic mechanism, and endogenous dopaminergic tone is likely to be increased during the luteal phase compared to the follicular phase. Consequently, the positive responses of cortisol and ACTH to MCP observed in the subjects during the mid-luteal phase may be related to the increased dopaminergic tone.

Adrenocorticotropic Hormone↗
PubMed1989

Unique mixed lymphocyte-stimulating determinants in Ed alpha gene-introduced C57BL/6 transgenic mice.

A unique mixed lymphocyte-stimulating determinant(s) was detected in Ed alpha gene-introduced C57BL/6 transgenic mice using alloreactive T-cell clones. Such unique determinant(s) was not detected by primary mixed lymphocyte culture reactions. The possibility that such unique determinant(s) was created by the combinatorial association of Ed alpha transgene products with endogenous Ab beta gene products is discussed.

Animals↗
PubMed1989

[Transseptal suture fixation in the management of prosthetic valve dehiscence].

Valve dehiscence resulted from prosthetic valve endocarditis and aortitis is the most common cause of the reoperation after prosthetic valve replacement. In our experience, the results of reoperation has been far from satisfactory. For the successful management of prosthetic dehiscence, we have adopted the transseptal suture technique of accurately securing the prosthetic valve. Five patients with prosthetic valve dehiscence and one patient with native valve endocarditis were operated upon using the transseptal techniques. Left ventricular-aortic discontinuity was repaired using composite valve-tube graft together with this technique in two patients. All but one patient who succumbed to multiple organ failure induced by preoperative hemodynamic deterioration have survived the operation without recurrent infective endocarditis or valve dehiscence.

Adult↗
PubMed1989

[Allogeneic bone marrow transplantation as primary treatment in acute myelofibrosis].

A 20-year-old man with acute myelofibrosis received ablative chemotherapy consisting of busulfan, Ara-C and cyclophosphamide followed by bone marrow transplantation from his histocompatible sister. There was a prompt engraftment with a rising WBC and platelet count and with donor karyotype in specimen of marrow. A bone marrow examination on day 29 showed a prominent decrease in marrow fibrosis. However, fibrosis was again exacerbated with leukemic relapse as overt acute megakaryoblastic leukemia on day 110, The patient died on day 126. Marrow fibrosis was found to be reversible by ablation of malignant cells and repopulation of normal hemopoietic cells after bone marrow transplantation.

Acute Disease↗
PubMed1988

Noninvasive measurement of elastic properties in human finger arteries: clinical data comparing blood pressure and funduscopic examination.

A portable device equipped with a transmitted infrared photoelectric plethysmograph (TIPP) and compression cuff was designed for indirect estimation of elastic properties of the arteries. Volume elastic modulus (Ev) was noninvasively measured by the device at controlled transmural pressure (Pt) levels in the finger arteries of 116 normal subjects and 50 patients with hypertension. Finger arterial pressure was simultaneously measured by this device using a volume oscillometric technique. There was a nonlinear relation between Ev and Pt, as reported previously by other investigators. Ev increased with Pt showing a minimum at Pt of about 0 mmHg. The Ev values increased with age and were higher in men than in women, when the same age groups were compared. The averages of the normal values were determined from regression equations relating Ev and age with respect to Pt and sex, assuming that there is an exponential relation. The normal range was tentatively determined as +/- 25% of the average Ev. The average Ev values obtained from the hypertensive patients (69 +/- 8 years old, n = 21 for males; and 70 +/- 11 years old, n = 29 for females) were significantly higher than the average normal values when same age groups at Pt = 60 mmHg were compared. Twenty-seven (54%) of the patients showed higher and 10 (20%) lower values than the normal range, while 13 patients (26%) were within the normal range at Pt = 60 mmHg. A significant correlation was not observed between the Ev values and the systolic, mean, and diastolic pressure values in the finger arteries of the hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Simplified method for preparation of concentrated exoproteins produced by Staphylococcus aureus grown on surface of cellophane bag containing liquid medium.

A simplified method for preparation of concentrated exoproteins including protein A and alpha-toxin produced by Staphylococcus aureus was successfully devised. The concentrated proteins were obtained by cultivating S. aureus organisms on the surface of a liquid medium-containing cellophane bag enclosed in a sterilized glass flask. With the same amount of medium, the total amount of proteins obtained by the method presented here was identical with that obtained by conventional liquid culture. The concentration of proteins obtained by the method, however, was high enough to observe their distinct bands stained on polyacrylamide gel electrophoresis. This method was considered quite useful not only for large-scale cultivation for the purification of staphylococcal proteins but also for small-scale study using the proteins. The precise description of the method was presented and its possible usefulness was discussed.

Bacterial Toxins↗
PubMed1988

Effect of temperature on antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa.

The effect of temperature on the antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa was investigated in vitro. At 10 C at which S. aureus organisms do not grow and might be metabolically inactive, the antibacterial activity of lidocaine to S. aureus was not observed in a concentration of 1%, which was quite antibacterial to S. aureus at 37 C. On the other hand, at 40 C a conspicuously increased antibacterial activity to S. aureus of lidocaine was observed in a concentration of 0.25% which was not antibacterial to S. aureus organisms at 37 C. Similar results were obtained when P. aeruginosa organisms were examined in place of S. aureus, although P. aeruginosa was found to be less susceptible to lidocaine than S. aureus. The clinical significance of the thermal effect on the antibacterial activity of lidocaine was discussed in brief.

Drug Resistance, Microbial↗
PubMed1988

Luminol-dependent chemiluminescence in antibody-sensitized neutrophils stimulated with protein A-bearing staphylococci.

When mouse polymorphonuclear leukocytes (PMNs) sensitized with rabbit antibody to mouse Ehrlich ascites tumor cells were stimulated by Staphylococcus aureus Cowan I cells, a conspicuous luminol-dependent chemiluminescence was observed in the absence of opsonin. The profile of the chemiluminescence (CL) response evoked by staphylococcal cells from antibody-sensitized PMNs had two peaks. An initial peak, observed within 1 min after stimulation, was sharp and high and a second peak, observed about 5 min after stimulation, was low and extended. The CL response of antibody-sensitized PMNs stimulated by S. aureus Cowan I cells was dose-dependently blocked by preincubation with soluble SpA. Cells of a mutant derived from S. aureus Cowan I strain with trace amounts of cell-bound SpA failed to stimulate the antibody-sensitized PMNs to generate the CL response. The antibody-sensitized PMNs were found to phagocytize SpA-bearing S. aureus cells even in the absence of opsonic serum. These results suggest that the observation presented here might provide a useful tool for the investigation of CL response of PMNs.

Animals↗