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Biomedical subjects

K Asano

Publications and source records attributed to K Asano.

At least 487 records · Page 27Linked to original sources
PubMed1984

A longitudinal assessment of anaerobic threshold and distance-running performance.

Longitudinal changes in the anaerobic threshold (AT) and distance-running performances (DRP) were assessed with a 4.5-month interval between the pre-, mid-, and post-tests in a relatively homogeneous (in terms of both maximal aerobic power and DRP) sample of 21 male, trained, endurance runners (means age = 18.5 yr) than had been employed previously. ANOVA with repeated measures followed by the Newman- Keuls post-hoc comparison revealed that there were significant alterations in both DRP and AT. Even in this improved state, higher relationships (r greater than or equal to 0.75) between the DRP and AT-related attributes held up consistently over the 9-month training period. Anaerobic threshold (expressed as ml O2 X min-1 X kg-1) showed a correlation higher than 0.80 with 10,000-m race time in every set of tests. When the relationships between the absolute amount of change in the Vo2@AT and the absolute amount of change in DRP were evaluated, significant correlations (r = -0.56 to -0.83) were found in several different time periods. Running velocity at AT (V@AT) also improved significantly, and was closely related to DRP changes. It is speculated that DRP changes are more directly accounted for by the Vo2@AT and/or V@AT changes rather than changes in other physiological attributes.

Adolescent↗
PubMed1983

Relationships of anaerobic threshold and onset of blood lactate accumulation with endurance performance.

This study was undertaken to compare the contribution of both the anaerobic threshold (AT) and onset of blood lactate accumulation (OBLA) with endurance performance in eleven non-endurance trained active male adults. AT determination was based upon both blood lactate and gas exchange criteria, while OBLA was determined as the point corresponding to a blood lactate concentration of 4 mmol X 1(-1). A dependent t-test revealed significantly higher values for OBLA related variables as compared with corresponding AT related variables, thereby validating the comparison of these two categories of variables in relation to endurance performance. Approximately 67, 60, 37, and 50% of the variance in endurance performance were accounted for by AT-VO2 (ml X kg-1 X min-1), AT-WR, OBLA-VO2 (ml X kg-1 X min-1), and OBLA-WR, respectively. When AT-HR (X2) was added to the AT-VO2 (X1) as another predictor, the contribution of these variables to endurance performance increased appreciably to 84%. The resultant multiple regression equation was Y = -4.564 X1 + 2.68 IX2 + 90.6 (SEE = 9.9 s). Consequently, it is suggested that variables related to an abrupt increase in blood lactate, together with several gas exchange responses, could explain endurance performance in a shorter distance to a greater extent than variables related to a rigid threshold of 4 mmol X 1(-1).

Adult↗
PubMed1983

Sinus node potential during cold cardioplegia.

Epicardial potentials of the sinus node, the right atrium, and the right ventricle were recorded in dogs during cold potassium-induced cardioplegia. We found that the sinus node fibers were more resistant to the cardioplegia than were the other myocardial fibers. When the cardioplegia rendered the atrial muscle inexcitable, the high frequency atrial potential was delayed and then abolished in the sinus node electrogram, and a smooth tracing similar to the action potential of the sinus node cell appeared. These findings should be pertinent for the cardiac surgeon attempting to avoid surgically-induced sinoatrial arrhythmias.

Action Potentials↗
PubMed1983

Structural requirements for hemolytic activity of F-glycoprotein of HVJ (Sendai virus) studied by proteolytic dissection.

The structure-function relationship of F and HN glycoproteins of HVJ were studied by proteolytic dissection. Three types of effects on the biological activity and structure of the virus particles were observed. First type of effect is preferential inactivation of biological activities related to F glycoprotein, such as hemolytic and cell fusion-inducing activities. Among enzymes which exert such effects, trypsin split F1 subunit to F1a (32,000 daltons) and F1b (19,000 daltons). By N-terminal determination, F1a was found to be derived from the N-terminal segment of F1, whereas F1b seems to correspond with the C-terminal segment of F1. Chymotrypsin and thermolysin digestion resulted in decreases in molecular weight of F1 subunit by about 3,500 daltons and 2,500 daltons, respectively. This splitting was found to occur near the N-terminus of F1, since new N-terminal amino acids were identified from the modified F1's. The second type of effect is characterized by specific splitting (for example, by a Staphylococcal proteases) of HN glycoprotein without affecting F protein. The third type has no apparent effect on the biological activities of the virion, although slight structural change of F glycoprotein was noted in some case. Exposure of the N-terminal segment of F1 to the surrounding aqueous medium despite its highly hydrophobic nature is shown by its easy splitting by aminopeptidase M, chymotrypsin and thermolysin. Based on these and previously published results, we hypothesize direct interaction of the hydrophobic segment with the lipid bilayers of the target cell membrane as an important step in fusion reactions between the viral envelope and plasma membranes.

Hemolysis↗
PubMed1983

Physicochemical characterization of Tween 80-hydrolyzing esterases produced by rapidly growing mycobacteria.

Tween 80-hydrolyzing esterases produced by various species of rapidly growing mycobacteria were partially purified from sonicated cell lysates by diethylaminoethyl (DEAE) cellulose and subsequent Sephadex G-150 column chromatographies. The amount of the esterase produced per gram of bacterial cells varied markedly with each species. Mycobacterium smegmatis, M. chelonei, and M. phlei were high producers and M. chitae and M. diernhoferi were low producers of Tween-hydrolyzing esterase. The resistance of each mycobacterial strain to oleic acid correlated well with their esterase-producing ability. All the esterases studied were adsorbed on DEAE cellulose in 50 mM Tris-HCl buffer (pH 7.5), indicating that they are acidic proteins. Esterases of M. smegmatis, M. chitae, M. fortuitum, and M. phlei were eluted from DEAE at high concentrations (0.11-0.18 M) of ammonium sulfate, while those of M. parafortuitum and M. diernhoferi were eluted at lower concentrations (0.05-0.08 M). With Sephadex G-150 gel filtration, all esterases were shown to have similar molecular weights (36,000 to 58,000). On the basis of heat-stability and trypsin- or chymotrypsin-sensitivity, these esterases were divided into three groups: one was heat-stable and protease-sensitive (M. smegmatis and M. fortuitum), another was heat-labile and protease-resistant (M. chelonei), and the other was the intermediate of the above two groups (M. diernhoferi).

Chymotrypsin↗
PubMed1983

Surgery for chronic pericarditis--thirty-years' experience.

During the past 3 decades, surgical treatment was performed on 75 cases with chronic exsudative or constrictive pericarditis, except for cases suffered from malignant tumor or trauma. Among 7 cases with chronic exsudative pericarditis, 5 underwent pericardiectomy and 2 had a fenestration of the pericardium. As for constrictive pericarditis, pericardiectomy was performed on 68 cases. Excellent surgical results were obtained. The ages of the cases with constrictive pericarditis, who underwent surgery, were significantly higher in the last decade, and the occurrence of pericardial tuberculosis significantly decreased in the last 2 decades. Although pericardiectomy has been performed for constrictive pericarditis without exception, it also plays an important role in the treatment of chronic exsudative pericarditis, especially for cholesterin or tuberculous pericarditis.

Adolescent↗
PubMed1983

[Chemotherapy of gastrointestinal cancer in elderly patients--evaluation of combination therapy with mitomycin C and 5-fluorouracil].

Sixty-three elderly patients with gastrointestinal cancer were treated with 5-fluorouracil (5-FU) or tegafur alone, and a combination of mitomycin C (MMC) and 5-FU. Judged by Koyama-Saito's criteria, the combination treatment was superior to single drug therapy. The response was somewhat correlated with survival in the combination regimen although it produced more gastrointestinal and myelotoxicities than the single drug. Our results suggest that the combination of MMC and 5-FU is useful in the treatment of gastrointestinal cancers in the elderly.

Aged↗
PubMed1983

[Clinical responses and side effects of aclarubicin (ACR) in the treatment of multiple myeloma].

Fifteen patients with multiple myeloma received Aclarubicin (ACR) alone intravenously. Nine of fourteen patients (one patient with non-secretory myeloma was excluded) achieved more than a 25% reduction in M-protein (limited response = LR). Two of LR patients obtained more than a 50% reduction (good response = GR). The median total dose of ACR and the median time required to reach LR or GR were 210 mg and 28 days, respectively. One of two patients achieved a marked regression of tumor mass and two patients showed a remarkable improvement in subjective symptom. Hematological toxicities were frequently observed. However, cardiac toxicity was not detected and epilation was mild.

Aclarubicin↗
PubMed1983

[Agraphia of the left hand--its characteristics and mechanism of development].

We observed 62 y.o. right-handed woman, whose truncus of corps callosum was damaged by infarction of left anterior cerebral artery, that was verified by coronal CT scan finding. She was apraxic and agraphic only with left hand. We examined the characteristics of her unilateral left agraphia from the point of quantitative and qualitative views. These analysis seemed to reveal three main characteristics of unilateral left agraphia of this patient. These were as follows; 1) productive, 2) neographic and 3) iterative. Another important feature of this patient was the mute state during her left-hand writing. Her left agraphia could not explained by apraxic factor, because her copying capacity was remarkably preserved in comparison with her dictation or written naming ability. Furthermore, this agraphia was not aphasic because her right-hand writing was almost intact. We agreed with Yamadori who insisted that this type of agraphia was neither apraxic nor aphasic, but the particular third agraphia which was named as "disconnection agraphia". We considered that the mute state during her left-hand writing might some kind of transient aphasia, which may reflect the functional disturbance of left hemisphere, and the reduced energy in the left hemisphere could increase the activity of right hemisphere. Partial interhemispheric disconnection might induce transient "linguistic anosognosia" in this patient. We believe that these transient hyperactivity and transient linguistic anosognosia could generate above mentioned characteristics of her left agraphia; productive, neographic and iterative.

Agraphia↗