Background and Purpose-Animal studies suggest that nitric oxide (NO) is important in basal cerebral blood flow (CBF) regulation and that it may mediate the vasodilatory response to carbon dioxide. We investigated its role in the human circulation using the NO synthase inhibitor N

ABSTRACT

Transplant renal artery stenosis (TRAS) is a common complication after transplantation and is an important cause of graft dysfunction. Damage from graft rejection, trauma, and atherosclerosis have been implicated as possible causes. We reviewed all 917 patients transplanted in our unit since 1978 to study the prevalence, clinical features, and possible causes of TRAS. Seventy-seven patients with TRAS were identified. The detected incidence was 2.4% before the introduction of color doppler ultrasonography (CDU) and rose to 12.4% after CDU was introduced in 1985, giving an overall incidence of 8.4% during a mean follow-up period of 6.9 years. The TRAS group was compared with a control group of 77 transplanted patients matched for age, year of transplant, sex, and number of previous grafts. Mean ages for the study and control groups were 43.6 +/- 15 and 44.8 +/- 13.7 yr. A total of 25% of cases of TRAS were diagnosed within the first 8 wk of transplantation and in 60% within the first 30 wk (median = 23 wk). All patients were treated with angioplasty, 28 patients had recurrence of TRAS requiring multiple angioplasties (maximum 5) and 1 went on to have surgery. Angioplasty resulted in a significant fall in plasma creatinine. Patient and graft survival were significantly worse in the TRAS group: 69% vs. 83% (P < 0.05) and 56% vs. 74% (P < 0.05) (TRAS vs. Control), respectively. There was a significantly higher incidence of rejection, especially cellular rejection in the TRAS group, 0.67 vs. 0.35 episodes per patient (P < 0.01) (TRAS vs. Control). Recurrence but not occurrence of TRAS was associated with the use of cyclosporine.

Immunohistochemical study may be used for detecting micrometastases by their expression of tumor-associated antigens. In 48 specimens of colorectal cancer from 47 patients, 49 of 249 lymph nodes (median, five per patient; range, 2-11) examined by light microscopic study contained tumor deposits. Sections of all lymph nodes were also examined by immunohistochemical study for carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA) expression using the indirect immunoperoxidase staining method. All 49 lymph node metastases (100%) from 20 patients stained positively for CEA and 45 (92%) expressed EMA. Of the 200 lymph nodes without metastases on light microscopic examination, anti-CEA revealed a single micrometastasis in a patient staged as Dukes' B. No additional metastases were detected with anti-EMA. In this series of patients immunohistochemical study has, therefore, influenced the histologic staging in only one patient (2%) and thus does not offer a significant benefit over conventional histologic staging.