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K Nawata

Publications and source records attributed to K Nawata.

27 records · Page 2Linked to original sources

Prostacyclin analog OP2507 prevents pulmonary arterial and airway constriction during lung preservation and reperfusion.

BACKGROUND: The effects of OP2507 on lung preservation with cold Euro-Collins solution and during the reperfusion period were evaluated. METHODS: For this study, canine lungs were flushed with a 10 micrograms/ml OP2507 solution (n = 7) or saline solution (control group, n = 7) (0.1 ml/kg body weight) and stored in the same solution. Pulmonary arterial pressure, pulmonary vascular resistance, airway pressure, respiratory capacity, and wet to dry weight ratio of the lungs were measured before and after 24 hours of cold preservation and after a 60-minute reperfusion period. RESULTS: Treatment with OP2507 significantly attenuated increases in pulmonary arterial pressure, pulmonary vascular resistance, and airway pressure after preservation and during the reperfusion period. Oxygen tension in outflow blood also was maintained with OP2507 treatment throughout the experimental period, whereas it was depressed during the reperfusion period in the control group. By electron microscopy, there was little evidence of vascular endothelial damage, such as cell swelling, detachment of endothelial cells from the lamina, and attenuation of the cytoplasm, in both groups. However, the tight junctions between cells were observed more clearly in the control group than in the OP2507 group, suggesting more cell membrane damage in the control group. CONCLUSIONS: Pretreatment with OP2507 prevented pulmonary artery and airway constriction after 12 hours of cold lung preservation and a decrease of oxygen tension in outflow blood during a 60-minute reperfusion period.

Animals↗

Knee deformities in multiple hereditary exostoses. A longitudinal radiographic study.

For a mean period of 7.8 years, the morphology of knee deformity and its annual changes in 8 patients (16 knees; mean age at the initial examination, 8.4 years) with multiple hereditary exostoses were evaluated radiographically. Knee deformity developed during the growth spurt period. Genu valgum with a femorotibial angle that decreased more than 2 standard deviations from the mean of age-matched normal children was observed in 6 of the 16 knees. In 3 of these 6 knees, recurrent dislocation of the patella was observed. Angulation of the femur varied among the knees, but the tibia showed valgus angulation in the proximal metaphysis in all knees. Thus, knee deformity in patients with multiple hereditary exostoses was primarily genu valgum caused by valgus angulation of the tibia.

Child↗

Osseous lesions associated with anterior cruciate ligament injuries. Assessment by magnetic resonance imaging at various periods after injuries.

In 56 patients with anterior cruciate ligament (ACL) rupture, we retrospectively examined osseous lesions secondary to the rupture using magnetic resonance imaging (MRI). Depending on the time from their ligamentous injury to the performance of MRI, the patients were divided into three groups: the acute group (less than 1 month, n = 20), the subacute group (between 1 and 12 months, n = 16), and the chronic group (12 months or more, n = 20). Occult osseous lesions which were not detected by roentgenography were revealed by MRI in 14 patients in the acute group (70.0%), 5 in the subacute group (31.3%), and 1 in the chronic group (5%). The detection rate of osseous lesions by MRI was significantly higher in the acute group than in the other groups (P < 0.001). Osseous lesions were always detected in the same locations of the lateral compartment of the knee joint. When examined by arthroscopy, these lesions were often found to be accompanied by articular cartilage injuries. In the acute group, osseous lesions were visible in the high signal intensity area of T2-weighted images and in the low signal intensity area of proton density images. They were interpreted as representing hemorrhage and edema within the bone marrow. In the subacute and chronic groups, the osseous lesions were smaller, and their signal intensity on T2-weighted images was lower than that in the acute group, probably reflecting the ongoing resorption of the hemorrhage and healing of the lesions. These results suggest that osseous lesions develop following injury to the ACL.

Adolescent↗

Isolated lung perfusion with cisplatin in a rat lung solitary tumor nodule model.

BACKGROUND: The present study was conducted to evaluate the toxicity, pharmacokinetics and anti-tumor potency of isolated lung perfusion (ILP) with cisplatin in a visible lung tumor nodule model in rats. MATERIALS AND METHODS: A solitary tumor nodule was established by the injection of Methylcholanthrene-induced sarcoma cells into the left lung. Thirty rats were randomized to undergo ILP with either 0.1, 0.25, or 0.5 mg/mL cisplatin and buffered hespan (BHE), or with an intravenous injection of 1.0 or 2.5 mg cisplatin. RESULTS: The highest dose of cisplatin tolerated by the rats was 0.1 mg/mL for perfusion. A much higher platinum concentration in the tumor, of 6.67 +/- 1.64 vs. 2.51 +/- 0.60 micrograms/g tissue, but a significantly lower concentration in the serum and kidneys, was achieved by perfusion compared to that achieved by intravenous injection. A significantly lower tumor weight and 20% complete treatment response was achieved in rats given cisplatin than in those given BHE perfusion at 43.9 +/- 11.6 vs. 226.3 +/- 44.6 mg. CONCLUSION: ILP with cisplatin achieved superior results to intravenous injection according to the levels of toxicity and pharmacokinetic analysis, and it was effective against a visible tumor nodule model in rats.

Animals↗