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Biomedical subjects

H Oyabu

Publications and source records attributed to H Oyabu.

At least 19 recordsLinked to original sources

Energy expenditure during walking in amputees after disarticulation of the hip. A microprocessor-controlled swing-phase control knee versus a mechanical-controlled stance-phase control knee.

We have compared the energy expenditure during walking in three patients, aged between 51 and 55 years, with unilateral disarticulation of the hip when using the mechanical-controlled stance-phase control knee (Otto Bock 3R15) and the microprocessor-controlled pneumatic swing-phase control knee (Intelligent Prosthesis, IP). All had an endoskeletal hip disarticulation prosthesis with an Otto Bock 7E7 hip and a single-axis foot. The energy expenditure was measured when walking at speeds of 30, 50, and 70 m/min. Two patients showed a decreased uptake of oxygen (energy expenditure per unit time, ml/kg/min) of between 10.3% and 39.6% when using the IP compared with the Otto Bock 3R15 at the same speeds. One did not show any significant difference in the uptake of oxygen at 30 m/min, but at 50 and 70 m/min, a decrease in uptake of between 10.5% and 11.6% was found when using the IP. The use of the IP decreased the energy expenditure of walking in these patients.

Artificial Limbs↗

%VO2max as an indicator of prosthetic rehabilitation outcome after dysvascular amputation.

In this study, independent ambulation of at least 100 metres with/without a cane was regarded as successful prosthetic rehabilitation. The subjects were classified into two groups according to this criterion at the time of discharge. The successful group attained this performance, the other group failed to reach this level. The successful group included 8 unilateral trans-femoral amputees aged 72.2 +/- 2.1 years who underwent amputation at more than 70 years, and succeeded in walking with a prosthesis. The group which failed included 9 unilateral trans-femoral amputees aged 63.2 +/- 2.1 years who underwent amputation between the ages of 60-65 years, and had great difficulty in walking with a prosthesis. The purpose of this research was to investigate whether or not %VO2max as an indicator of physical fitness is useful in predicting prosthetic rehabilitation outcome after dysvascular amputation by comparing these two groups. Evaluation of physical fitness was conducted before the subjects began prosthetic rehabilitation. Information about each subject before fitting with a prosthesis was collected retrospectively from clinical charts made during admission. The successful group were capable of strenuous exercise, reaching the intensity of 50% VO2max or more. In the group which failed only one reached the intensity of 50% VO2max. The working capacity of 50% VO2max or greater would appear to be a valid initial guideline level of physical fitness at which an amputee can expect to succeed in walking with a prosthesis. Apart from physical fitness, a lesser number of comorbidity, good ability to stand on the remaining leg, and a strong will to walk were found to be important factors contributing to successful prosthetic rehabilitation. This study also showed that age alone was not an important factor.

Aged↗

The efficacy of physiological cost index (PCI) measurement of a subject walking with an Intelligent Prosthesis.

The Intelligent Prosthesis may enable lower limb amputees to walk faster than with conventionally damped prostheses and as a result the physical burden involved in walking could be expected to be considerably higher. The aim of this study was to investigate whether or not physiological cost index (PCI) is applicable as an indicator for monitoring the amount of exercise load involved in walking with an Intelligent Prosthesis. The method used a treadmill and monitored gas exchange, ventilation and heart rate (HR) in 6 unilateral trans-femoral amputees, ages were between 17 and 34 with an average age of 23.1. The exercise protocol was as follows: for each person speeds at 0.8 times the subject's free level walking speed, 1.0 times, 1.2 times, 1.4 times and for some 1.6 times were applied. In each case the index of correlation between PCI and oxygen uptake in response to walking speed was calculated. A significant correlation was observed between PCI and oxygen uptake in each case, which indicated a close relationship between cardiopulmonary factor and energy consumption while walking. These results suggest that PCI is of use as an indicator for ascertaining the amount of exercise load in walking with an Intelligent Prosthesis.

Adolescent↗

The efficacy of the one-leg cycling test for determining the anaerobic threshold (AT) of lower limb amputees.

The aim of this study was to investigate whether or not the one-leg cycling test driven by the subject's sound leg as the exercise load method is an applicable method for determining the anaerobic threshold (AT) of lower limb amputees. To evaluate physical fitness, a graded exercise test that monitored gas exchange, ventilation and heart rate (HR) was performed in 51 unilateral lower limb amputees. AT was successfully measured for 42 out of 51 subjects, an 82.3% success rate. The average AT was 12.7 +/- 2.2 ml/kg/min, and the average HR at AT points was 117.7 +/- 16.2 beats/min. The average peak oxygen uptake was 20.1 +/- 5.6 ml/kg/min, and the average peak HR was 145.1 +/- 22.4 beats/min. The peak HR exceeded the HR at AT by an average 27.4 beats/min, which indicates that a comparatively intense exercise load above the AT level is possible. The average AT was 40.9% of the predicted maximum oxygen uptake, which seems reasonable when compared to the reports of other researchers. These results suggested that the one-leg cycling test driven by the sound limb is of use as a method for determining the AT of lower limb amputees.

Adolescent↗

[Evaluation of urgent treatment for impacted bile duct stones].

One hundred and forty-four urgent treatments for acute obstructive suppurative cholangitis (AOSC), acute obstructive cholangitis (AOC), or/and acute pancreatitis caused by impacted bile duct stones were performed for eight years from 1984 to 1991. The breakdown of these treatments are as follows. [table: see text] It was not easy to diagnose every severe case of AOSC. As a result, however, endoscopy was very effective both in diagnosis and treatment. Concerning patients with thinner bile duct, endoscopic drainage was useful than percutaneous drainage. We prefer ENBD to EST followed by basket extraction of bile duct stones in an emergency state. ENBD is a rather easy technique even for beginners of ERCP, and is less invasive. The life-saving effect of ENBD is not inferior to that of EST.

Acute Disease↗

Nonbacterial transformation of bilirubin in bile.

Bilirubin present in gallstones is mainly in the unconjugated form despite the frequent absence of bacteria in bile. The aim of the present study was to determine if nonbacterial beta-glucuronidase activity and/or nonenzymatic hydrolysis is responsible. Inflammatory cells such as polymorphonuclear leukocytes and lymphocytes appearing with the presence of brown pigment gallstones and inflammation in biliary tract was shown to effect deconjugation of bilirubin conjugates in bile and contribute to their formation in addition to that of bacterial beta-glucuronidase. Gallbladder bile (mean +/- SD, 4.0 +/- 1.6%, N = 29) contained more unconjugated bilirubin than hepatic bile (mean +/- SD, 2.7 +/- 1.1%). In vitro experiments showed the deconjugation to take place during incubation at 37 degrees C without the presence of bacteria. Therefore, transformation of conjugated to unconjugated bilirubin is likely to take place in vivo during the storage in gallbladder, and nonbacterial beta-glucuronidase activity and/or nonenzymatic hydrolysis may be responsible for such transformation.

Bacteria↗

[Clinical investigation of serum immunosuppressive acidic protein (IAP) in patients with gastric cancer].

Immunosuppressive acidic protein (IAP) is among the immunosuppressive factors so far detected in the blood of cancer patients. This study was undertaken to determine the blood level of IAP in patients with carcinoma of the gastrointestinal tract, particularly the stomach, and to define the clinical implications of IAP for the therapy. A close correlationship was established between the serum IAP level and the gross degree of malignancy of the tumor and clinical stage of disease, notably in patients with gastric cancer; the serum IAP level was increased with as the disease advanced, the increase being significant in the presence of metastasis or extensive spread of the lesion.

Adult↗

[Concentrations of cefotaxime in serum and myocardial tissue].

Serum and myocardial concentrations of cefotaxime (CTX) were measured in 20 adult patients undergoing cardiac surgery. To all of these patients 1.0 g of CTX was given intravenously (in the range of 13.7--29.0 mg/kg) at the beginning of operation. The serum concentrations of CTX were determined at 5, 10, 30, 60 minutes and 120 minutes after administration. Myocardial concentrations of CTX were also determined at about 30 minutes (group I), 60 minutes (group II) and 120 minutes (group III). The following results were obtained. Average serum CTX concentrations were 132.8 +/- 34.1 micrograms/ml at 5 minutes, 92.0 +/- 23.1 micrograms/ml at 10 minutes, 44.6 +/- 12.3 micrograms/ml at 30 minutes, 24.5 +/- 7.7 micrograms/ml at 60 minutes and 12.3 +/- 4.9 micrograms/ml at 120 minutes after administration. Average myocardial CTX concentrations were 10.0 +/- 3.7 micrograms/g in group I, 3.6 +/- 2.1 micrograms/g in group II and 2.3 +/- 1.8 micrograms/g in group III. The myocardial/serum concentration ratio was 0.22 +/- 0.14 in group I, 0.15 +/- 0.08 in group II and 0.18 +/- 0.12 in group III, respectively. These results suggested that the serum and myocardial concentrations of CTX were high enough to be prophylactic and therapeutic against not only aerobic but also anaerobic and opportunistic infections during and after cardiac surgery.

Adult↗

[Clinical studies of serum protease inhibitors in hepatoma].

The hemorrhagic disposition of patients with hepatic cirrhosis and hepatoma may be associated with DIC. Thus, elucidation of the role of coagulation and fibrinolysis inhibition factors as hemostatic mechanisms in living organisms and in the growth or metastasis of neoplasms is important. Therefore, we measured the levels of serum protease inhibitor and plasminogen in hepatoma patients and compared them with those of patients with other hepatic diseases. Hepatoma was found to induce a marked increase in the alpha 1 AT, alpha 1X and C1 INA levels and a marked decreased in the I alpha I and Pmg levels. The alpha 2 M and AT III levels showed a wide distribution; no significant difference was observed between the hepatoma group and the normal control group. However, hepatoma patients with the DIC syndrome showed a marked decrease in their AT III, Pmg, alpha 2M and I alpha I levels and an increase in their alpha 1 AT and alpha 1X levels. Moreover, the serum protease inhibitor levels corresponded closely with the clinical course.

Carcinoma, Hepatocellular↗