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Biomedical subjects

K Hara

Publications and source records attributed to K Hara.

At least 991 records · Page 55Linked to original sources
PubMed1986

[Mitral regurgitation due to ruptured chordae tendineae: sensitivity and specificity of the diagnostic criteria by two-dimensional echocardiography].

The sensitivity and specificity of the two-dimensional (2D) echocardiographic criteria for diagnosing ruptured mitral chordae tendineae (RCT) were assessed in 52 cases with non-rheumatic mitral regurgitation undergoing mitral valve prostheses. At surgery, chordal rupture was confirmed in 38 cases (RCT group), but not in 14 cases (non-RCT group). Four presumptive and three definite findings for diagnosing mitral chordal rupture using 2D echo were evaluated. Mitral valve prolapse with incomplete coaptation of the mitral leaflets in the long-axis view was observed in 32 cases in the RCT group and in four cases in the non-RCT group (sensitivity 84%, specificity 80%). In the short-axis view at the level of the mitral orifice, delayed closure of the involved mitral leaflet was observed in four cases in the RCT group but in none of the non-RCT group (sensitivity 11%, specificity 100%), delayed protodiastolic opening of the involved leaflet in 15 cases of the RCT group and in one of the non-RCT group (sensitivity 39%, specificity 92%), and finally, increased excursion of the involved valve in 27 cases of the RCT group and in three cases of the non-RCT group (sensitivity 71%, specificity 79%). The following three echocardiographic findings were regarded as direct evidence of mitral chordal rupture: Fine echoes with abnormally rapid transverse and/or oblique motion around the mitral orifice in the short-axis view were observed in 13 cases of the RCT group (sensitivity 34%, specificity 100%); echoes with abnormal whip-like motion in the long-axis view in 10 cases (sensitivity 26%, specificity 100%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

[The penetration of cefotaxime into the cerebrospinal fluid. Comparison between acute and chronic stages in intracranial diseases].

Two grams of cefotaxime (CTX) were administrated by drip infusion to 10 patients (11 material) with acute or chronic stage of intracranial diseases. Concentrations of CTX in the serum and the cerebrospinal fluid (CSF) were determined at 15, 30, 60, 120, 240 and 300 minutes after injection. The results obtained were summarized as follows: Serum levels: Peak levels of CTX in sera were 66.2 +/- 10.23 (S.E.) micrograms/ml in the acute stage group (ASG), and 75.7 +/- 31.39 (S.E.) micrograms/ml at 15 minutes after injection in the chronic stage group (CSG). There were no significant difference between the 2 groups. CSF levels: Peak levels of the drug in CSF were 1.35-4.32 micrograms/ml in ASG and 0.18-0.7 microgram/ml in CSG. Average concentration at 60 minutes after injection was 1.11 +/- 0.09 (S.E.) micrograms/ml in ASG and 0.30 +/- 0.08 (S.E.) micrograms/ml in CSG. The value in ASG was significantly higher than the value in CSG by t-test. The ratio between CSF and serum levels: The levels increased as time passed in both groups and the values in ASG were higher than those in CSG at all time points. Average ratios at 60 minutes after injection were 3.85 +/- 0.29 (S.E.)% in ASG and 1.12 +/- 0.50 (S.E.)% in CSG. The value in ASG was significantly higher than that in CSG by t-test. From the above results, it is considered that CTX is useful for the prophylaxis of postoperative infections in intracranial diseases.

Adult↗
PubMed1986

[Clinical evaluation of astromicin by intravenous drip infusion. Report I. Bacterial infections in the field of internal medicine].

Intravenous drip infusion of a new aminoglycoside agent, astromicin (ASTM), was used against various infections in the field of internal medicine, and its clinical efficacy and safety were studied. Clinical effects were evaluated in 105 among 111 patients administered with ASTM. Almost all the patients were given 200 mg of ASTM twice a day by intravenous drip infusion for 60 minutes. Among 105 cases, clinical effects of ASTM were excellent in 15, good in 56, fair in 10 and poor in 24. The number of cases who were judged as excellent or good was 71, and the efficacy rate was 67.6%. Efficacy rates classified by diseases were as follows; 80% (4/5 cases) in sepsis, 55.6% (5/9 cases) in urinary tract infections, and 68.1 (62/91 cases) in respiratory tract infections (RTI). In 91 cases with RTI, clinical effects of ASTM were excellent in 14, good in 48, fair in 9 and poor in 20. The efficacy rates classified by diseases of RTI were 77.3% (34/44 cases) in pulmonary parenchyma infection and 59.6% (28/47 cases) in chronic RTI and others. As subjective and objective side effects, tinnitus and malaise were observed in 5 (4.5%) of 110 patients evaluated for side effects. But, either symptom was mild and disappeared after the end or withdrawal of administration. Slight elevations of S-GPT, BUN and others were observed in 7 cases (6.4%) as abnormal laboratory test values. Safety and efficacy of intravenous drip infusion of ASTM were confirmed.

Adult↗
PubMed1985

Receptive field mechanisms of ganglion cells in the cat retina.

On the basis of anatomical and physiological results of the vertebrate retina, a method is proposed for analysing the respective fields of ganglion cells in the cat retina. In the model, we assume the following: (a) Ganglion cells receive their input from bipolar and/or amacrine cells. (b) The nonlinearity of ganglion cell responses is due to the activities of transient type amacrine cells. The method has been proved to be effective. According to the results of this investigation, the receptive field properties of X type and Y type ganglion cells are heterogeneous. Thus, it may be considered that their receptive fields consist of center and surround mechanisms. The receptive field properties of X-cells are almost linear and the X-cells seem to receive most of their input from bipolar cells. On the other hand, the ones of Y-cells are highly nonlinear. Consequently, it is conceivable that the Y-cells receive their input mainly from transient type amacrine cells.

Animals↗
PubMed1985

Identification and estimation algorithm for stochastic neural system. II.

The algorithm for identifying the stochastic neural system and estimating the system process which reflects the dynamics of the neural network are presented in this paper. The analogous algorithm has been proposed in our preceding paper (Nakao et al., 1984), which was based on the randomly missed observations of a system process only. Since the previous algorithm mentioned above was subject to an unfavorable effect of consecutively missed observations, to reduce such an effect the algorithm proposed here is designed additionally to observe an intensity process in a neural spike train as the information for the estimation. The algorithm is constructed with the extended Kalman filters because it is naturally expected that a nonlinear and time variant structure is necessary for the filters to realize the observation of an intensity process by means of mapping from a system process to an intensity process. The performance of the algorithm is examined by applying it to some artificial neural systems and also to cat's visual nervous systems. The results in these applications are thought to prove the effectiveness of the algorithm proposed here and its superiority to the algorithm proposed previously.

Animals↗
PubMed1985

Sensitive enzyme immunoassay for the quantification of aclacinomycin A using beta-D-galactosidase as a label.

A sensitive enzyme immunoassay method (EIA) for an anticancer drug, aclacinomycin A (ACM), has been developed. With a double-antibody technique, ACM at a concentration as low as 100 pg/tube can be detected. An antibody to ACM was obtained by immunizing rabbits with an antigen prepared by coupling ACM with mercaptosuccinylated bovine serum albumin via N-maleoyl aminobutyric acid (MABA) as a coupling agent. Enzyme labeling of ACM was performed with beta-D-galactosidase (beta-Gal; EC 3.2.1.23) via m-maleoyl benzoic acid (MBA). The standard curve of the assay was linear on a logit-log plot over a concentration range of 30 pg to 10 ng. The antibody detected ACM and its metabolites, MA144 M1 (M1), MA144 N1 (N1), MA144 S1 (S1), and aklavin (T1) equally well, but was only minimally reactive with aklavinone (D1) and 7-deoxyaklavinone (C1), thus suggesting that this EIA can detect the total amounts of ACM and its biologically active glycosides among metabolites of ACM. This EIA is practically free from interference by any other anticancer drugs. Using this assay, serum levels of ACM equivalents can be determined accurately after administration of the drug to rats at a single dose of 10 mg/kg. Since ACM is now undergoing clinical trial, the EIA of the drug will be a valuable tool in clinical pharmacological studies.

Aclarubicin↗
PubMed1985

Respiratory superinfections after the use of third-generation cephem antibiotics.

This paper is a report on our studies on superinfections in respiratory tract infections treated during the years 1981-1984. The isolated strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis, Streptococcus faecium and glucose non-fermentative gram-negative rods such as Pseudomonas aeruginosa were resistant to third-generation cephem antibiotics. These organisms proved to be widely distributed in hospitals and were frequently isolated from the sputum, excised lung and cardiac blood. The colonization of the sputum by bacteria in respiratory tract infections before, during and after treatment with third-generation cephem antibiotics revealed a tendency for these organisms to appear after treatment. Among the gram-positive cocci, S. faecium was most resistant to these antibiotics, followed by S. faecalis, S. epidermidis and S. aureus in that order. The incidence of resistant isolates in 1984 exceeded that in 1983, suggesting an annual increase in resistant bacteria.

Cefotaxime↗
PubMed1985

Giant aneurysm of the splenic artery and huge varix.

Giant aneurysm of the splenic artery and huge varix accompanied by portal hypertension and splenomegaly are described. Computed tomography proved to be an ideal tool in the evaluation of both aneurysm and varix. Enhancement scan revealed giant aneurysm as a round mass in the splenic hilus and huge varix as one oval and one bell-shaped shadow adjacent to the spleen. They were diagnosed by angiography.

Adult↗
PubMed1985

Acute hemolysis associated with hepatitis A.

A 62-yr-old woman, admitted to Mitsui Memorial Hospital with complaints of jaundice, general malaise and anorexia, was diagnosed as acute hepatitis A by positive IgM anti-HA. On the 13th hospital day, indirect hyperbilirubinemia (total bilirubin 57 mg/dl, indirect bilirubin 38.5 mg/dl) and splenomegaly were noted. Hemoglobin concentration decreased to 8.4 g/dl and reticulocytes increased to 6%. Bone marrow showed hyperplastic marrow with erythroid hyperplasia. Coombs test was negative. After administration of prednisolone 40 mg daily for 30 days, hemoglobin concentration increased to 11.9 g/dl and total bilirubin was decreased to 0.4 mg/dl. The liver biopsy specimen obtained on the 62nd day, revealed recovery stage of acute hepatitis. Jaundice with increased indirect bilirubin, anemia with reticulocytosis, elevated plasma hemoglobin concentration and predominance of LDH1 were indicative of hemolysis. The enzyme activities in the red blood cells, which were taken 1 year after the onset, were within normal limits. Scanning electron microscopy of the red cells showed no significant abnormalities in their shape and the nature of the surface.

Anemia, Hemolytic↗
PubMed1985

Impaired natural killer cell activity in Bloom's syndrome could be restored by human recombinant IL-2 in vitro.

Natural killer (NK) activity against K562 tumor cells was evaluated in peripheral blood nonadherent mononuclear cells (PBMNC) obtained from four patients with Bloom's syndrome. NK activity of PBMNC from all patients was found to be depressed to less than half of age-matched control values. However, all patients showed the normal percentages of large granular lymphocytes and of cells expressing the NK-cell-associated determinants (OKM1, Leu-7, and Leu-11). Although recombinant interferon-beta or -gamma augmented NK activity of patients' PBMNC in a manner similar to their effects on NK activity of normal individuals, impaired NK activity of PBMNC from Bloom's patients could be restored to normal ranges only by recombinant interleukin 2 (IL-2). These results suggested that IL-2 and interferons might participate in boosting NK activity of Bloom's syndrome in different ways.

Adolescent↗
PubMed1985

Aicardi syndrome. Report of 6 cases and a review of Japanese literature.

This report presents 6 cases of Aicardi syndrome (infantile spasms, agenesis of the corpus callosum, chorioretinopathy), and a review of Japanese literature. Two patients developed Lennox-Gastaut syndrome following infantile spasms. Visual evoked potential was examined in every case with binocular and monocular flash stimulations. Normal response was obtained in 5 cases, and no response in 1. Auditory brainstem response was examined in 2 cases. Central conduction time was prolonged in 1 case.

Agenesis of Corpus Callosum↗
PubMed1985

Production of monoclonal antibodies against Legionella pneumophila serogroup 1.

Four monoclonal antibodies to Legionella pneumophila Philadelphia 1 were produced by the fusion of immunized BALB/c lymphocytes to a murine myeloma cell line. Two (Lp1-1 and Lp1-3) of the four monoclonal antibodies reacted with 14 L. pneumophila serogroup 1 strains, and the other (Lp1-2 and Lp1-4) reacted with only three out of 20 strains tested. These four monoclonal antibodies did not bind to any strains of L. pneumophila serogroup 2-7 and other Legionella species. In addition, it has been shown that these monoclonal antibodies may be useful not only for subserotyping of L. pneumophila but also for retrospective diagnosis using immunopathological methods.

Antibodies, Monoclonal↗
PubMed1985

Effects of a Fusobacterium nucleatum extract on immunoregulation in mice.

The purpose of this study was to examine the effect of an extract of Fusobacterium nucleatum on humoral and cell-mediated immunity and phagocyte functions in mice. The extract was obtained from the heat-inactivated supernatant of sonicated F. nucleatum. Mouse splenocytes were cultured with sheep red blood cells (SRBC), and antibody formation was assayed by counting the plaque-forming cells (PFC). After C3H mouse skin was grafted onto the BALB/c mouse, cytotoxicity of BALB/c mouse splenocytes to L-cells was enumerated, T- and B-cell blastogenesis was determined by the uptake of 3H-thymidine. In vivo phagocyte functions were measured using carbon clearance test, bactericidal, and acid phosphatase activity assays. The number of SRBC-specific and non-specific PFC in splenocytes stimulated with the extract increased 2.5-8.7-fold over that of unstimulated splenocytes. Cytotoxicity of splenocytes from the extract-injected mice decreased in a dose-dependent fashion at 12 days after grafting. T-cell mitogenicity of the extract was observed. The carbon clearance rate was reduced, and bactericidal and acid phosphatase activities were elevated by the extract injection of the mice. In conclusion, F. nucleatum extract has an adjuvant effect on humoral immunity, and a suppressive effect on cell-mediated immunity and activated phagocyte functions.

Animals↗