PubMed Health⌕ Search

Biomedical subjects

K Makita

Publications and source records attributed to K Makita.

At least 19 recordsLinked to original sources
PubMed1992

Influence of oophorectomy on serum levels of sex steroids and bone metabolism and assessment of bone mineral density in lumbar trabecular bone by QCT-C value.

The present cross-sectional study was carried out to determine the influence of oophorectomy (OPX) on serum levels of sex steroids and bone metabolism, as well as bone mineral density (BMD), in OPX subjects in comparison with age- and body size-matched controls. Quantitative computed tomography (QCT) and dual-photon absorptiometry (DPA) demonstrated a remarkable reduction in BMD in OPX subjects. In particular, the QCT of the centrum of vertebral bone (QCT-C) in these subjects was no more than 69.33 +/- 3.40% (X +/- SEM) of the control value, and this parameter was much lower than the QCT integral (QCT-I) value of total lumbar vertebrae. This means that BMD decreases specifically in spongy portions after OPX. The serum level of estrone (E1) was significantly lower in OPX subjects than in controls. The hormonal action of E1 on target organs has been thought to be only one-third of that of estradiol (E2), but the marked reduction in serum E1 level seemed to be a significant cause of the reduction in BMD. The serum level of androstenedione (delta 4) significantly decreased in OPX subjects and appeared to affect bone metabolism negatively. Both bone formation and bone resorption were found to be stimulated following OPX, but the rate of bone resorption was found to be higher than that of bone formation: there was an imbalance between bone formation and bone resorption in OPX subjects. However, it was not possible to prove a relationship between Ca regulating hormone and this phenomenon. In conclusion, the QCT-C value reflects the changes in spongy vertebral BMD more sensitively than the QCT-I value or DPA.(ABSTRACT TRUNCATED AT 250 WORDS)

Androgens↗
PubMed1992

Contrast-enhanced magnetic resonance imaging of sub- and epidural empyemas.

Contrast-enhanced magnetic resonance images (MRI) of three patients with subdural (SDE) and two with epidural empyemas (EDE) were reviewed. In each case, the capsule of the lesion demonstrated enhancement, and distinction between capsule and contents was obvious on contrast-enhanced images. In SDE, contrast-enhanced images clearly depicted thickening of the neighbouring dura mater and a co-existent brain abscess. In EDE, part of the displaced dura mater did not enhance, which facilitated differentiation from SDE. Contrast-enhanced MRI was thus of value in diagnosis.

Adolescent↗
PubMed1992

Which is more osteoporosis-inducing, menopause or oophorectomy?

The present study was designed to investigate in a comparative manner whether menopause or oophorectomy (OPX) would be a more osteoporosis-inducing factor with regard to sex steroids, bone metabolism and bone mineral density (BMD), including postmenopausal subjects, OPX subjects and age- and body-size-matched premenopausal controls. Serum levels of estradiol (E2), testosterone (TS) and dehydroepiandrosterone (DHEA) were found to decrease in both the postmenopausal and OPX subjects without any significant difference between them, while serum levels of estrone (E1) and androstenedione (delta 4), which have been reported to be related to bone metabolism, were significantly lower in the OPX subjects than in the postmenopausal subjects. According to the indices representing bone formation and bone resorption, as well as the changes in serum levels of Ca-regulating hormones, bone metabolic balance seemed to be slightly more negative in the former than in the latter. However, there was no difference between these two groups of subjects with regard to BMD in lumbar vertebral spongy portion which sensitively reflects the changes in total lumbar BMD and bone metabolism and in which compressive fracture is apt to occur. This fact suggests that these two groups of subjects may be managed in the same way in clinical practice. In other terms, the menopause, a natural event in women, influences BMD as much as OPX, which is the greatest risk factor in osteoporosis, does.

Androgens↗
PubMed1992

Intravascular foreign bodies: loop-snare retrieval system with a three-lumen catheter.

A foreign body retrieval system composed of a three-lumen catheter, a guide wire, and a wire loop nearly perpendicular to the axis of the catheter was used to retrieve catheter fragments located in the inferior vena cava in two patients and in the superior vena cava in one patient. Fragments were looped within 1 minute of catheterization and were retrieved without complication. Catheter fragments placed in the pulmonary artery of one dog were also successfully retrieved.

Animals↗
PubMed1992

Guide-wire-directed detachable balloon: clinical application in treatment of varicoceles.

Wire-directed detachable balloons were used in embolization treatment of varicoceles in six patients. Advancement of the balloon over a guide wire allowed easy embolization of the internal spermatic vein at the level of the inguinal ring. Additional detachable balloons were used to occlude the collateral vessels to the varicocele. This method proved highly effective in embolization of tortuous veins and in placement of multiple balloons.

Adolescent↗
PubMed1992

Effect of nipradilol on cardiovascular hemodynamics during exercise in angina pectoris with old myocardial infarction.

Nipradilol (3,4-dihydro-(2-hydroxy-3-isopropylamino)-propoxy-3-nitroxy-2H-1- benzopyran, K-351, CAS 81486-22-8) is a new type of beta-blocker with vasodilating action. The effect of nipradilol on hemodynamics at rest and during exercise with a multi-stage bicycle ergometer in supine position was studied in 8 male patients suffering from angina pectoris with old myocardial infarction. Nipradilol was orally given at the daily dose of 12 mg (b.i.d.) for one week, and various hemodynamic parameters were measured at rest and during exercise before and after the treatment with nipradilol. At rest, the blood pressure was almost unchanged, heart rate was significantly reduced, cardiac output tended to decrease, and the pulmonary blood pressure and left ventricular ejection fraction (EF) were almost unchanged. At peak exercise, the blood pressure tended to decline, heart rate was significantly reduced, cardiac output tended to decrease and the pulmonary blood pressure and EF increased significantly. Consequently, the antianginal effect of nipradilol is considered to be attributable to the reduction in myocardial oxygen consumption caused by a decrease in double product. It is thus suggested that nipradilol exerts its antianginal effect without adversely affecting the cardiac performance.

Adrenergic beta-Antagonists↗
PubMed1992

[Anesthetic management of a patient with right ventricular myxoma].

Right ventricular myxoma in a 79 year old male, whose pulmonary trunk was obstructed by the myxoma, was reported. Myxoma of the heart is rare, and especially right ventricular myxoma is rare. Myxomas of the heart have been reported by thirty-seven authors, but right ventricular myxoma has been reported by only one author. Anesthesia for the removal of right ventricular myxoma must be carried out carefully, because some critical troubles may happen during anesthesia for the resection of the right ventricular myxoma. Particularly, occlusion of the pulmonary artery is the most dangerous complication.

Aged↗
PubMed1991

Comparison of oxygen consumption measurements: indirect calorimetry versus the reversed Fick method.

OBJECTIVE: To compare measurement of oxygen consumption (VO2) by spirometry and the reversed Fick method. DESIGN: Within-patient comparison using simultaneous measurements by the two methods, one previously calibrated on a metabolic simulator. PATIENTS: Twenty sets of observations on eight patients (57 to 83 yrs) requiring mechanical ventilation in a critical care unit. INTERVENTIONS: None during or immediately before the measurements. MEASUREMENTS AND MAIN RESULTS: Duplicate pairs of measurements of VO2 were made with a previously validated spirometric technique and the reversed Fick method (Qt[CaO2 - CVO2]), where Qt is cardiac output, CaO2 is arterial oxygen content, and CVO2 is mixed venous oxygen content. The coefficient of variation of the difference between duplicate measurements by the former technique was only 2.53% compared with 10.4% for the latter. The mean VO2 measurement by the spirometric method was 285.7 +/- 40.7 (SD) mL/min standard temperature and pressure, dry (STPD) and for the reversed Fick method, the mean VO2 measurement was 249.3 +/- 38.5 mL/min STPD. The mean difference was 36.4 +/- 28.5 mL/min STPD (p less than .001). CONCLUSIONS: The repeatability of the spirometric method was four times better than the reversed Fick method. The latter gave a significantly lower value that probably, in part, reflects the VO2 of the lung, which is included in the spirometric method but not in the reversed Fick measurement.

Aged↗
PubMed1991

Relocatable Gianturco expandable metallic stents.

The authors modified Gianturco expandable metallic stents to make them relocatable. Two tandem designs were made. The first design had long struts and, thus, more evenly distributed expansive force; the second had short struts and more flexibility and was better suited for use in curved strictures. Both designs (two to four in tandem, 0.012-, 0.014-, and 0.018-inch wire) were tested successfully in vitro, and both designs (two to four in tandem, 0.012-inch wire) were successfully placed, retrieved, and relocated in the inferior vena cava of five dogs.

Animals↗
PubMed1991

Wire-directed detachable balloon. Work in progress.

A new silicone detachable balloon has two self-sealing valves. The proximal valve grips the catheter tip, and the distal valve allows a guide wire to pass through. The balloon is advanced over the guide wire. Detachment is performed after the wire is withdrawn. Five balloons were successfully placed in the intended arteries and veins of three dogs. This wire-directed detachable balloon is placed more easily and accurately than the conventional detachable balloons that are placed with the flow-directed method.

Angiography↗
PubMed1991

Embolization with steel coils using a saline flush technique.

A method using saline flush to push Gianturco steel coils through catheters is described, and has been successfully used in 45 patients. The saline flush technique requires no precise matching of coils and catheters, solves problems associated with the conventional method and simplifies the coil embolization procedure.

Arteries↗
PubMed1991

[Influences of menopause and oophorectomy on bone metabolism and spinal bone mineral content].

The present study was performed on bone metabolism and spinal bone mineral content (BMC) in 3 groups of age- and body size-matched subjects: Thirty-three postmenopausal subjects, 37 oophorectomized (OPX) subjects and 22 premenopausal subjects. Serum levels of Alp and osteocalcin (OC) as indices of bone formation, U-Ca/cr and U-hydroxyproline (Hpr)/cr as indices of bone resorption, and Ca-regulating hormones, M-PTH, calcitonin (CT) and 1,25(OH)2D; were measured and spinal BMC was determined by QCT. Alp and OC levels were slightly higher in the postmenopausal group than in the OPX group and, in contrast, U-Ca/cr and U-Hpr/cr were slightly higher in the latter. The M-PTH level was slightly higher in the latter, and the CT level in the former. There was no difference in the 1,25(OH)2D level between two groups. For BMC, there was no difference between the two groups. The above results corresponded to the previously reported significant reductions in sex steroids. OPX seemed to affect bone metabolism more than menopause, there was no specific influence of OPX on spinal BMC as compared with QCT findings in postmenopausal subjects. Our previous study and the present study demonstrated that, at an interval of about 3 years after menopause or OPX, the endocrine system and bone metabolism tended to be more affected by OPX. However, BMC did not reflect any influence of OPX, or of menopause. There was no clear clinical difference between postmenopausal subjects and the OPX subjects with regard to the osteoporotic condition.

Alkaline Phosphatase↗
PubMed1990

Evaluation of metabolic measuring instruments for use in critically ill patients.

We evaluated three commercial indirect calorimetry devices which are used during artificial ventilation. Commercial butane, which had an RQ of 0.615, consumes 6.40 ml oxygen, and produces 3.94 ml CO2/1 ml, was burned in a gas-tight combustion chamber in conjunction with the ventilation of a lung model. During combustion, the flow rate of butane was measured with a soapfilm flowmeter for the calculation of reference values of oxygen consumption (VO2) and CO2 production (VCO2). To investigate the effect of oxygen concentration on the accuracy of these instruments, measurements were carried out at FIO2 values of 0.3, 0.4, 0.5, and 0.6 with a fixed ventilation mode (tidal volume 500 ml; respiratory rate 16 breath/min, intermittent positive-pressure ventilation). For the Datex Deltratrac Metabolic Monitor, the mean relative errors of measured VO2, VCO2, and RQ were all within 4.0%, 2.9%, and 4.0%, respectively. For the Engstrom Metabolic Computer, the corresponding values were 1.4%, 5.7%, and 6.0%, and for the SensorMedics MMC Horizon, 5.7%, 2.9%, and 5.9%.

Calorimetry↗
PubMed1990

Hepatic inferior vena cava obstruction: treatment of two types with Gianturco expandable metallic stents.

Gianturco expandable metallic stents were used for treating six patients with inferior vena cava (IVC) obstruction due to compression by large hepatic tumors and three patients with idiopathic obstruction of the hepatic IVC and Budd-Chiari syndrome who showed reocclusion or stenosis 3-21 months after previously performed percutaneous transluminal angioplasty (PTA). In all six patients with compression by hepatic tumors, stents dilated the IVC and debilitating edema of the lower body disappeared. In the three patients with idiopathic obstruction, stents were placed after repeat dilation of the lesions and Budd-Chiari syndrome did not recur during a follow-up period of 7-10 months. In two of the three, cavograms obtained 8 months after placement showed the channels to be open with minimal intimal thickening. Gianturco expandable metallic stents can correct IVC obstruction due to compression by hepatic tumors and are useful in preventing reocclusion of the IVC after PTA for the treatment of idiopathic obstruction. The authors recommend using tanem stents connected by at least two struts.

Aged↗
PubMed1989

Validation of oxygen consumption measurements during artificial ventilation.

We describe a system for the absolute calibration of indirect calorimeters, under the conditions of artificial ventilation and increased inspired O2 concentration, in which butane, at a measured flow rate, is burned downstream of an artificial lung. One milliliter of butane requires 6.4 ml O2 for its combustion, and the respiratory quotient is 0.615. With the closed-circuit O2-replenishment method there was no significant systematic error in the measurement of either O2 consumption or CO2 output and a random error with a SD of 8.3 ml/min for O2 consumption and 6.3 ml/min for CO2 output. There were no significant differences in the errors with inspired O2 concentrations between 23.8 and 59.5% and O2 consumptions between 89 and 366 ml/min.

Butanes↗
PubMed1989

[Laryngeal mask--a newly designed oral airway].

A newly developed oral airway, laryngeal mask (LM), was used in 40 patients by anesthesiologists of varied clinical experiences. Clear airway was obtained in 37 patients (92.5%). There were 3 patients in whom it was difficult to establish clear airway, probably because of inappropriate fitting of mask to larynx or of folding of epiglottis. Controlled or assisted ventilation was performed adequately in most of the patients, but there was recognizable gas leak in 13 patients when the airway pressure was above 15 cmH2O. The LM has many attractive features compared with a traditional face mask, and some of the promising clinical applications of LM are discussed.

Adolescent↗
PubMed1989

[MR findings of metastatic brain tumors].

Fifteen cases with metastatic brain tumor(s) were examined on a 1.5T MR system and the results were evaluated along with images of contrast-enhanced CT. Gd-DTPA-enhanced T1-weighted imaging (T1WI) showed the best detectability of lesions and was followed by contrast-enhanced CT, T2WI, and non-enhanced T1WI in that order. No correlation was found between the MR signal intensity and the histological classification of the tumors. In differential diagnosis with glioblastoma, several signal characteristics were encountered. Low or isointensity as well as the discrimination of tumor from edema on T2WI was considered to suggest the diagnosis of metastatic tumor.

Adult↗