Biomedical subjects

H Takami

Publications and source records attributed to H Takami.

314 records · Page 18Linked to original sources

PubMedDate not supplied

Myocardial energy metabolism in preserved heart: comparison of simple storage and hypothermic perfusion.

Isolated canine hearts were preserved for 24 hours by either simple hypothermic storage in Collins' M solution (group 1, n = 7) or hypothermic perfusion with oxygenated modified Krebs solution (group 2, n = 7), followed in both cases by reperfusion with cross circulation. Myocardial biopsies taken consecutively during preservation and after reperfusion were analyzed for high energy phosphates (adenosine triphosphate [ATP], adenosine diphosphate [ADP], adenosine monophosphate [AMP], and creatine phosphate), their catabolites (inosine), and lactate. In group 1, ATP decreased from 23.7 +/- 2.8 mumol/gm dry weight (mean +/- standard deviation) at 0 hours to 5.6 +/- 2.8 mumol/gm dry weight at the end of preservation. Creatine phosphate decreased and lactate increased significantly during 24 hours of preservation. The consumption rate of ATP appeared to have decreased after 18 hours of preservation. In group 2, ATP, creatine phosphate, and lactate remained at control levels during preservation. Coronary vascular resistance, however, increased significantly. After reperfusion functional measurements of the hearts in both groups did not vary significantly, despite the difference in myocardial ATP content (11.2 +/- 4.9 mumol/gm dry weight in group 1 and 17.9 +/- 3.9 mumol/gm dry weight in group 2; p less than 0.05). Simple hypothermic storage manifested a limitation in terms of energy store compared with hypothermic perfusion, whereas the latter appeared to have a risk of possible myocardial damage caused by the perfusion itself.

Animals↗

PubMedDate not supplied

Noninvasive assessment of myocardial viability by measuring adenosine triphosphate degradation product in coronary sinus effluent of preserved dog heart.

Isolated dog hearts (n = 19) were preserved in cold Collins solution at 4 degrees C for 1 to 26 hours. At the end of preservation the coronary system was flushed out by cold cardioplegic solution, and the hearts were reperfused with supporting dogs. Myocardial biopsies at the end of preservation and coronary sinus effluents at the time of flush-out were analyzed for adenosine 5'-triphosphate and inosine. Both the degree of depletion in adenosine triphosphate content and the accumulation of inosine in the myocardium during preservation correlated significantly to the preservation time (correlation coefficient = -0.85 and 0.86, respectively). There was a significant correlation between the myocardial inosine level and total amount of inosine released into coronary sinus effluent (correlation coefficient = 0.91, p less than 0.001). Also, a significant correlation between the total amount of inosine in coronary sinus effluent and cellular level of adenosine triphosphate was found (correlation coefficient = -0.86, p less than 0.001). Five hearts that failed to resume beating showed significantly higher amounts of released inosine than the other hearts (3.3 +/- 0.9 versus 1.5 +/- 0.5 mumol, p less than 0.005). These results indicate that the inosine level in the coronary sinus effluent reflects the myocardial energy state, and it is suggested that the measurement of inosine level in the effluent may be applicable as a noninvasive method for assessment of myocardial viability in heart preservation.

Adenosine Triphosphate↗

PubMedDate not supplied

Influence of gender on allograft rejection in a rat heart transplant model.

BACKGROUND: Clinical studies have reported increased rejection in female heart transplant recipients. Conflicting data exist as to whether rejection is increased with male donors or female donors in these female recipients. METHODS: We investigated in this study allograft rejection in four sets of gender combinations with and without immunosuppression with the use of a heterotopic rat heart transplant model: male donor heart to female recipient, female donor heart to female recipient, male donor to male recipient, and female donor to male recipient. To examine the possible effect of androgens as an immunosuppressant, we orchiectomized a group of male recipient rats before transplantation. The rats that were not immunosuppressed were evaluated for length of graft survival (palpation). In the immunosuppressed rats (cyclosporine, 10 mg/kg x 7 days) in each gender combination half of the grafts were evaluated for length of survival (palpation) and half for cellular rejection grade at day 14 (microscopy). RESULTS: When rats that underwent transplantation were not immunosuppressed, no difference in graft survival time was found among the four sets of gender combinations. With immunosuppression, median graft survival time was 23 days in female recipients versus 32 days in male recipients (p < 0.05). Mean cellular rejection grade at day 14 was 2.95 +/- 0.7 in female recipients and 0.8 +/- 0.4 in male recipients (p < 0.01). No significant difference was found in graft survival time or cellular rejection grade with respect to donor gender. The graft survival times and cellular rejection grades of the male rats undergoing orchiectomy were not different from those of normal male recipients (p = NS). Cyclosporine levels on day 7 in both male and female recipients were high, female levels (1039 +/- 411 ng/ml) were less than male levels (2029 +/- 379 ng/ml) (p < 0.01). CONCLUSIONS: Female recipients of heterotopic rat heart transplants had shorter graft survival time and increased cellular rejection as compared with male recipients. Donor gender had no influence on graft survival or cellular rejection grade. Orchiectomy had no influence on graft survival time or grade of rejection. Results of this model suggest that female recipients may require increased immunosuppression and rejection surveillance, regardless of donor gender.

Animals↗

PubMedDate not supplied

A case of cerebral air embolism predominant in the left cerebral hemisphere following subclavian catheterization.

We report a case of cerebral air embolism caused by right subclavian vein catheterization. A large amount of air was seen only over the left cerebral hemisphere on computed tomographic (CT) scans. Although neurological deficit was observed bilaterally at the onset, the degree of ischemic brain damage was far greater in the left cerebral hemisphere than in the right. This unusual left-sided predominancy of cerebral air embolism was presumably due to the tortuosity of the ascending aorta.

Aged↗

PubMedDate not supplied

Lithium in the preoperative preparation of Graves' disease.

Lithium carbonate is used in the preoperative preparation of Graves' disease. We experienced five patients with Graves' disease who received lithium preparations, because of adverse effects of conventional drugs such as methimazole and propylthiouracil. These patients showed successful surgical outcome without postoperative thyroid storms and recurrences. The administration of lithium carbonate is an effective method for preoperative management of Graves' disease when conventional antithyroid drugs show adverse effects.

Adult↗

PubMedDate not supplied

A rapid immunoperoxidase method for pathological diagnosis of occult thyroid carcinoma.

The authors report four unusual cases of clinically occult carcinoma of the thyroid. Exploratory excision of osseous metastatic lesions was performed for diagnosis in Patients 1 and 2, and fine needle aspiration of cervical metastatic lesions was used for diagnosis in Patients 3 and 4. A definite diagnosis of thyroid cancer could not be made by hematoxylin and eosin staining in Patient 2, nor by fine needle aspiration in Patient 3. However, the diagnosis of thyroid cancer in both patients was made using the rapid immunoperoxidase method with an antibody against thyroglobulin. The rapid immunoperoxidase method reported in this paper requires only about 5 minutes. Hence, this rapid staining method may be routinely applied to definitive identification of the thyroid as the source of metastatic lesions, prior to surgery.

Adenocarcinoma, Follicular↗

PubMedDate not supplied

Endothelin production in the rabbit collecting ducts of acute renal failure models. An immunohistochemical study.

Endothelin 1 (ET-1) production was examined in the rabbit nephron in acute renal failure (ARF) induced by uranyl acetate administration or by clamping the renal artery. Uranyl acetate dissolved in saline was injected intravenously at a dose of 0.8 mg/kg (n = 12). In the ischemic kidney experiment, 60 min of left renal artery clamping was carried out 1 week after removing the right kidney (n = 8). Plasma and urine concentrations of ET-1 were measured 0, 24, and 48 h after treatment, and immunohistochemical studies of renal tissues obtained 48 h after the experiments were carried out using ET-1 monoclonal antibody. The fractional excretion of ET-1 increased from 10 to 89% at 48 h in the uranyl acetate treated group and from 6 to 15% at 24 h in the renal artery clamping group, suggesting the existence of ET-1 secretion from the nephron in both types of ARF. By immunohistochemical examination, strong ET-1 expression was noted only in the collecting ducts. No staining was observed in other parts of the nephron in both types of ARF. The present study indicates that the increased expression of ET-1 probably reflects production by the collecting ducts in both rabbit ARF models.

Acute Kidney Injury↗

PubMedDate not supplied

Combination of calcitonin and pamidronate for emergency treatment of malignant hypercalcemia.

To combine the rapid hypocalcemic effects of calcitonin with the delayed effects of pamidronate, a combination of a single dose of pamidronate and serial doses of eel calcitonin was administered to five patients with malignant hypercalcemia for 2 to 5 days. The serum calcium levels of all five patients fell within 24 h after administration of pamidronate and the first dose of calcitonin and decreased to normal within 4 days. The mean level of corrected serum calcium fell from 15.3 mg/dl (range 14.1-16.4 ) to 9.2 mg/dl (8.9-9. 6) at the nadir. No toxicity or side effects were found. The results of this study demonstrate the value of combining the rapidly acting antiresorptive and renal calciuretic effects of calcitonin with the slower, but more potent effects of pamidronate. The combination of calcitonin and pamidronate allowed rapid, long-term control of hypercalcemia and it is regarded as the first choice of treatment in severe hypercalcemia.

Adenocarcinoma↗