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Biomedical subjects

S Naganuma

Publications and source records attributed to S Naganuma.

At least 73 records · Page 4Linked to original sources
PubMed1991

Development and clinical evaluation of the long time digital Holter ECG system using non-tracking technology.

Newly developed long time digital Holter ECG system utilizing a stamp-size non-tracking (NT) tape which can be used for 192 hours as 2ch recording, was evaluated in the clinical cases. The system has employed newly developed VLSIs and NT technology which enables to obtain reliable long time recording with smaller and lighter Holter system of ECG and variety of biological signals. The results indicated that good data reproduction was shown in this system.

Adult↗
PubMed1991

Systemic circulation with high frequency blood flow--analysis from neurophysiological point of view.

The vibrating electromagnetically driven univalved artificial heart, which provided more than 10 1/min at 10 Hz/sec. vibration, was developed in our team. This vibrating electromagnetic pump (VEMP) produced the original flow pattern compared with the flow pattern of the natural heart, so that circulatory regulatory system during maintain the circulation with VEMP must be investigated before the clinical application. In order to assess the effect of high frequency blood flow produced by the VEMP from the neurophysiological point of view, power spectral analysis of the hemodynamics was performed. VEMP was implanted as the total left heart bypass in adult goats and right heart circulation was maintained by natural hearts. In arterial blood pressure during maintain circulation by the high frequency blood flow, Mayer waves (0.01-0.15 Hz) were significantly decreased, though respiratory waves (0.25-0.40 Hz) were not significantly changed. These results suggest that circulatory regulatory system was influenced by the high frequency blood flow produced by the VEMP.

Animals↗
PubMed1991

Long-time inflation of the PTCA balloon.

For patients for whom the conventional percutaneous transluminal coronary angioplasty (PTCA) did not adequately improve stenosis, or sufficient angioplasty was impossible because of occurrence of dissection, we attempted using a long-time balloon inflation for more than 10 minutes. In order to allow the use of this balloon, we instituted an active rehabilitation program using a bicycle ergometer to promote the development of the collateral circulation up to the time of performing diagnostic angiography and PTCA, while attempting to use a perfusion balloon catheter for those patients not developing sufficient collateral circulation. Of the 134 patients undergoing PTCA, unsatisfactory angiographic results were obtained in 13 patients. Of these patients, long-time balloon inflation was performed in seven and primary success was achieved in six. From this study, we believe that the long-time balloon inflation in PTCA can improve the primary success rate and reduce postoperative complications.

Angina Pectoris↗
PubMed1991

Rapid improvement in a patient with leukocytoclastic vasculitis with secondary mixed cryoglobulinemia treated with cryofiltration.

A patient with leukocytoclastic vasculitis (LCV) with secondary mixed cryoglobulinemia was treated by cryofiltration in an effort to stop the progression of the disease despite the use of high dose prednisone. Three cryofiltration procedures within one week were performed on this patient. Clinical assessments made through the course of this therapy and the followup period showed excellent response. Peripheral blood mononuclear cell transformation functions (MNC-TF) were evaluated at the pre-1st and post-2nd cryofiltration treatment. MNC-TF pretreatment were significantly suppressed. Post-2nd cryofiltration, MNC-TF were improved. Our study demonstrates that cryofiltration is a safe and effective treatment of a patient with LCV with secondary mixed cryoglobulinemia, without requiring plasma replacement products.

Adolescent↗
PubMed1990

Clinical application of Fragmin (FR-860) in hemodialysis: multicenter cooperative study in Japan.

A multicenter cooperative study was designed to evaluate the efficacy and safety of Fragmin (FR-860) as an anticoagulant in hemodialysis. Sixty-one stable maintenance hemodialysis patients were enrolled from 14 institutions in Japan. The study period was fixed at 2 weeks. Dosage requirements were 15.0 to 20.0 anti-Xa U/kg as bolus and 7.5 to 10.0 anti-Xa U/kg/hr as continuous infusion. The total dosage of Fragmin was 2505 +/- 127 anti-Xa U compared with 6124 +/- 190 U of conventional heparin. No differences were observed in residual blood in extracorporeal circuits between the groups. The hemostasis times at puncture sites after completion of dialysis were significantly shortened in the Fragmin group (7.9 +/- 0.7 minutes) when compared with the conventional heparin group (11.4 +/- 1.1 minutes; p less than 0.01). Plasma anti-Xa levels were 0.24 +/- 0.03 and 0.36 +/- 0.04 U/ml 1 hour after the initiation and at the completion of dialysis, respectively. ACTs, measured by the Hemochron method, were not prolonged during dialysis. APTTs varied from 34.3 +/- 1.2 before dialysis to 41.0 +/- 1.9 (p less than 0.01) 1 hour after the start of dialysis and 39.9 +/- 1.6 seconds (p less than 0.01) at the end of dialysis. Plasma AT III activity increased from 96.8 +/- 2.5% before dialysis to 113.0 +/- 3.2% (p less than 0.01) at the end of dialysis. No significant changes were observed in both ADP- and collagen-induced platelet aggregation during dialysis. Dialysis efficiency was the same for both groups. Slight itching developed in one of 61 cases. No abnormal laboratory data were observed during the study. The efficacy, safety, and utility rates were 98.4, 98.5, and 98.4%, respectively. Fragmin proved to have a higher utility rate and was a good and convenient alternative to conventional heparin as an anticoagulant in hemodialysis treatment.

Antithrombin III↗
PubMed1990

A low CA++ level in effluent as a risk factor for the peritonitis in CAPD patients.

In vitro, some studies revealed the importance of the CA++ level in peritoneal macrophage functions in CAPD patients. We therefore retrospectively studied the relationship between the frequency of peritonitis and the concentration of Ca, Ca++, Interferon-r (IFN-gamma), Interleukin-1B (IL-1B) in the Pd effluent. Samples were taken during a peritonitis-free period. In a group of patients without peritonitis, the mean Ca++ level in the Pd effluent was 2.25 +/- 0.20 mEq/L, while in the other group with frequent episodes of peritonitis (more than one episode per 20 patient-months), the mean Ca++ level in PD effluent was 2.01 +/- 0.13 mEq/L which was significantly lower than the former (p less than 0.05). The mean Ca concentration in Pd effluent was also lower in the group with the high frequent peritonitis than the peritonitis-free group, but not significantly. The level of IFN-gamma is lower and IL-1B is higher in the group with frequent peritonitis than in the peritonitis-free group, although these differences were not significant. These evidences suggest that lower Ca++ level in the effluent of the frequent peritonitis group may impair the peritoneal macrophage function and peritoneal cell-mediated immune function and may increase a risk of the peritonitis. These results may offer a new approach for prophylaxis of peritonitis in CAPD patients.

Calcium↗
PubMed1989

Microscopic observation of leukocyte kinesis in the vascular bed during hemodialysis using the rabbit ear chamber technique.

Leukocyte kinesis in the capillary vascular bed during hemodialysis (HD) was investigated to elucidate the mechanism of transient leukopenia. Leukocyte movement was observed microscopically during HD using the rabbit ear chamber (REC) technique, which permits visualization of the movement of blood corpuscles in capillaries. Blood was drawn from the femoral artery and returned into the auricular and/or carotid artery so that the blood passing through the hollow fiber artificial kidney (HFAK) flowed into capillaries in the REC. Leukocyte counts of blood samples taken from the afferent and efferent limbs of the HD circuit, the right jugular vein and the right atrium were determined consecutively during HD. The difference in the leukocyte count was observed between the afferent and efferent limbs for the first 15 minutes and thereafter between the efferent limb and the jugular vein. The "transpulmonary" difference in the leukocyte count was not noticed throughout HD. Between 15 and 90 minutes after the start of HD, scarcely any circulating leukocytes were found in capillaries in the REC and some leukocytes were attached to the endothelial surface. Thereafter circulating leukocytes were seen again and detachment of leukocytes from the endothelial surface was observed. No leukocyte aggregation or embolization of aggregating leukocytes was noticed. This evidence suggests that leukopenia may be attributed to the transient shift of leukocytes to the marginal pool of the vessel lumen and this process may not be specific for the pulmonary vasculature, but may occur in the first capillary bed into which the blood passing through the HFAK flows.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Functional deterioration of the peritoneum: does it occur in the absence of peritonitis?

Peritoneal function in relation to the occurrence of peritonitis and the osmolarity of the dialysate was studied in 72 CAPD patients with a mean duration of treatment of 16.5 +/- 9.0 months (group 1). Data from 24 of these patients, who were on CAPD for longer than 2 years (average 28.6 +/- 4.9), were subjected to further detailed analysis (group 2). Each group consisted of two subgroups, one of patients who had experienced peritonitis and one of patients who had had no episodes of peritonitis. Results from group 1 revealed that the use of hyperosmolar bags increased in parallel with the duration of CAPD treatment even in the non-peritonitis subgroup, and that peritonitis enhanced the tendency to use hyperosmolar dialysate solutions. This phenomenon was also observed in the peritonitis subgroup of group 2, but was not apparent in the non-peritonitis subgroup of group 2 when examined as a whole: however, individual analysis revealed that some of them had a similar tendency to use hyperosmolar dialysate, as was seen in the peritonitis subgroup. These results confirm that the peritonitis impairs the ultrafiltration capability of the peritoneum. The results also suggest that the long-term use of hyperosmolar dialysate may be associated with decreased ultrafiltration, hence emphasis should be placed upon the use of hyperosmolar dialysate solutions for long-term CAPD.

Adult↗
PubMedDate not supplied

Sonographic findings of anomalous position of the gallbladder.

Anomalous position of the gallbladder is relatively rare and has been reported only in isolated case reports. We tried to determine its ultrasound (US) findings on the basis of 18 such patients. In the left-side gallbladder group (nine patients), the gallbladder was imaged as an oval cystic mass in front of the pancreas. In all patients, the narrow neck of the gallbladder was clearly detected by US in the usual location before the main portal vein. Four of nine patients had small gallbladder stones. The retrohepatic gallbladder group (four patients) showed marked atrophy of the right lobe of the liver. Two patients had multiple gallstones in the bile ducts of the right lobe. All patients in the suprahepatic retrohepatic gallbladder group (four patients) were cirrhotic, and the anterior segment of the right lobe was markedly atrophied. In the intercostal scan, the gallbladder mimicked a perihepatic fluid. In the floating gallbladder group (one patient), the gallbladder was imaged as a cystic mass in the anterior abdominal wall. Surgical intervention showed a severely inflamed gallbladder, with small stones adhered into the anterior abdominal wall and partially ruptured. Knowledge of the wide range of US findings of malposition of the gallbladder helps in avoiding misdiagnosis.

Adult↗
PubMedDate not supplied

LDL apheresis in atherosclerotic disease with hyperlipidemia.

Low density lipoprotein (LDL) apheresis was carried out in 28 atherosclerotic patients with clinical signs of poor peripheral circulation and abnormally high LDL levels. The LDL apheresis using extracorporeal adsorption with a dextran sulfate cellulose column (Liposorber, Kaneka, Japan) was done 10 times over 3 months. Hyperlipidemia was rapidly corrected after the initial two aphereses, whereas clinical signs of arteriosclerosis obliterans (ASO), such as coldness of the legs in 17 of 19 patients (89.5%), intermittent claudication in 14 of 17 patients (82.4%), foot pain at rest in 15 of 18 patients (83.3%), poor arterial pulsation in 12 of 16 patients (75.0%), and diminution of ulcer/necrosis in 3 of 5 patients (60.0%), improved in parallel. Improvement in plethysmographic and thermographic findings were observed in 10 of 10 patients (100.0%) and 13 of 14 patients (92.9%), respectively. Our tentative conclusion is that LDL apheresis using the Liposorber system was very effective in removing LDL from blood, and clinical symptoms rapidly improved in all patients concomitant with a reduction in plasma LDL levels. Hyperlipidemia may be a risk factor for symptomatic ASO in the lower extremities, and its active correction may be worth trying.

Aged↗
PubMedDate not supplied

Heparin-free hemodialysis with an oral anti-platelet agent.

Heparin-resistant blood clotting in hemodialysis, caused mainly by platelets activated with artificial materials, was ameliorated by oral administration of a newly developed anti-platelet agent, 4-cyano-5,5-bis (4-methoxy phenyl)-4-pentenoic acid (E5510, Eisai Co. Ltd., Tokyo, Japan). Six hemodialysis patients, who were given 0.5. 1, 2, and 4 mg of E5510 orally 1 to 2 hr before starting hemodialysis, underwent hemodialysis using a hollow fiber dialyzer (PMMA or cellulose acetate). The platelet aggregation rate was depressed according to dose response, and fell to less than 30% of the initial value with 2 mg of E5510. Plasma thromboxane B2 concentration was depressed significantly. Bleeding time was mildly but not significantly prolonged. Based on these results, we tried heparin-free hemodialysis using E5510 as sole anticoagulant. Six of nine patients were successfully hemodialyzed with minimal blood clotting in the dialyzer and drip chambers. Three patients needed additional low dose heparin to prevent blood clotting in the circuit's air trap. Neither hemorrhagic complications nor other side effects were observed in these cases. E5510 is considered to be a promising oral anti-thrombogenic agent for patients with heparin-resistant blood clotting or heparin-free hemodialysis.

Administration, Oral↗