Monoclinic hafnium oxynitride supported on reduced graphene oxide to catalyse the oxygen reduction reaction in acidic media.

Monoclinic HfO2 nanoparticles were doped with nitrogen via hydrothermal treatment that avoided high-cost pyrolysis with NH3 gas in order to develop a novel oxygen reduction reaction catalyst for use in acidic media. Catalyst size reduction was achieved using a reduced graphene oxide support, and activity above 0.8 V was obtained.

Fatal cardiac beta2-microglobulin amyloidosis in patients on long-term hemodialysis.

We report two long-term hemodialysis patients who developed severe congestive heart failure attributable to cardiac heavy amyloid deposition. Both patients became hypotensive during dialysis sessions, gradually making it difficult to continue hemodialysis, and they died of congestive heart failure. At autopsy, left ventricle walls in each case contained diffuse extensive deposits of amyloid. The distribution of amyloid was not localized to vessel walls but was widely disseminated throughout the left ventricle walls and replaced myocardial muscle fibers. Immunohistochemical examination showed positive staining for anti-human beta2-microglobulin antibody. We conclude that cardiac dialysis-related amyloidosis should also be considered in long-term hemodialysis patients with congestive heart failure as a life-threatening complication.

Rupture of thoracic aorta caused by penetrating aortic ulcer.

We present the findings in a 57-year-old man with a rupture of the thoracic aorta that originated in a penetrating atherosclerotic aortic ulcer. It formed a large hematoma that clinically mimicked a true saccular thoracic aneurysm. The possibility of penetrating aortic ulcer should be considered in the differential diagnosis of aortic aneurysm.

Hepatic injury localized to the field of total lymphoid irradiation.

A 37-year-old woman with severe aplastic anemia underwent allogeneic bone marrow transplantation following cyclophosphamide (CY) and total lymphoid irradiation (TLI). On day +30, a CT scan was carried out because of a mild elevation in liver enzymes, and it revealed a low density area with a sharp border in the left lobe corresponding to the irradiated area. MRI showed a hypersignal intensity on both T1 and T2-weighted images and suggested that hepatic damage was mainly severe fatty change. These abnormalities resolved with no treatment. CY with TLI for adult patients with severe aplastic anemia may induce hepatic injury.

Malignant lymphoma with myxoid change and sarcomatous features.

We report a case of unusual B-cell malignant lymphoma of the kidney and mediastinum. Renal biopsy showed prominent myxoid changes and sarcomatous features, leading to considerable difficulty in histologic diagnosis on routinely stained histologic sections. However, immunohistochemical staining for lymphocyte markers led to the final histologic diagnosis of B-cell malignant lymphoma. Although myxoid change is not generally found in malignant lymphoma, malignant lymphoma should not be excluded from consideration when one encounters a small round cell sarcoma with myxoid stroma, especially in extranodal soft tissue tumors.

[The significance of hypoplasia of the circle of Willis in patients with Binswanger-type cerebrovascular disease].

We evaluated the correlation between hypoplasia of the circle of Willis detected by MR angiography and ischemia of the white matter in patients with Binswanger-type cerebrovascular disease. We defined P1 hypoplasia as the condition in which the posterior cerebral artery at P1 protein was narrower than the posterior communicating artery, and A1 hypoplasia as that in which the ratio of the one anterior cerebral artery to the other at A1 portion was 1:2 or less. Of 68 patients with this disease. 33 (48.5%) had P1 hypoplasia and 23 (30.9%) had A1 hypoplasia. These incidences were significantly higher than those of patients with lacunar infarction (138 cases), where P1 and A1 hypoplasia were 29.0% and 18.1% respectively. P1 hypoplasia tended to be found more frequently in patients with lacunar infarction having advanced periventricular hyperintensity than in those having mild one. The large intracranial vessels, as seen by MR angiography, were less stenotic, and the serum concentration of apolipoprotein A-I was higher and B/A-I was lower in hypoplasia cases suffering from Binswanger-type cerebrovascular disease than in non-hypoplasia cases. In summary, hypoplasia of the circle of Willis was considered to precipitate the onset or progression of this disease without any relationship to arteriosclerosis.

[Clinical evaluation of renal cell carcinoma and acquired cystic disease of the kidney in long-term dialysis patients].

Long-term dialysis patients frequently develop acquired cystic disease of the kidneys (ACDK). One hundred and sixty-seven dialysis patients were classified into two groups according to the presence or absence of ACDK, and the two groups were compared with regard to the dialysis period, laboratory findings, and so forth. Among the 167 dialysis patients, 37.7% showed ACDK and had an average dialysis duration of 10.3 years, which was significantly longer than the 5.0 years for patients without ACDK. The proportion of patients with ACDK rose with increasing duration of dialysis; 64.6% of the patients on dialysis for more than 10 years had ACDK. The values of hemoglobin and hematocrit of patients with ACDK were significantly higher than those without ACDK. Of 12 dialysis patients who were operated upon because of suspected renal tumor, pathological examination confirmed renal cell carcinoma in 8 and adenoma in one. One of these patients had been treated with chronic ambulatory peritoneal dialysis, and another had bilateral renal tumor. Among the 8 patients with renal cell carcinoma, ACDK was detected in 5 by means of CT and ultrasound tomography, and cystic changes were observed in two on light microscopic examination of the resected kidneys. Pathological examination of the non-tumorous renal tissues revealed hyperplastic or adenomatous changes in the cyst epithelium in 5 patients undergoing dialysis for more than 7.5 years. These changes were thought to be pre-neoplastic. The high incidence of ACDK and the development of renal tumors in long-term dialysis patients indicates the necessity of intensive monitoring.

[Experience and results of application of remote afterloading system (RALS) optimization program for intracavitary treatment of squamous cell carcinoma of the uterine cervix].

An optimization program for a remote after-loading system (RALS) for intracavitary treatment of cancer of the uterine cervix was established in 1982 by Tabushi and his co-workers. This system has been used in our hospital since 1986, using MODULEX. Seventy-three cases of untreated squamous cell carcinoma of the uterine cervix have been treated under RALS, 29 under conventional RALS and 44 under the RALS optimization program. The cumulative 5-year survival rates were obtained for the groups treated under each system by the Kaplan-Meier method. The 5-year survival rate of stage II cases treated under the RALS optimization program was 68.2%, and that of stage III cases 58.5%. On the other hand, that of stage II cases treated under conventional RALS was 56.3%, and that of stage III cases 44.9%. There was no significant difference between these two groups. Local control rates for stage II and III cases were higher than 5 year-survival rates. Among complications, the frequency of grade 2 radiation colitis was 15.9% with the RALS optimization program cases, and that of grade 2 radiation cystitis was 4.5%. We consider the RALS optimization program to be a clinically useful method for the intracavitary treatment of squamous cell carcinoma of the uterine cervix.

Impaired metabolism of guanidinoacetic acid in uremia.

In order to investigate the guanidinoacetic acid (GAA) metabolism in uremia, we have measured serum guanidino compounds in patients with chronic renal failure (CRF) in comparison with normal subjects, and the renal content of GAA and glycine amidinotransferase (GAT) activity in the kidney of experimental CRF rabbits. Serum concentrations of guanidinosuccinic acid (GSA) and methylguanidine (MG) in the patients with CRF were higher than those in the normal subjects, as well as serum urea nitrogen (BUN) and creatinine (Cr) levels. The serum GAA levels were however, significantly lower and showed a tendency to decrease inversely with the elevation of BUN in the patients with CRF under conservative therapy. On the contrary, in the patients under maintenance hemodialysis (MHD) therapy, the serum GAA level did not decrease in spite of the elevation of BUN. Four anephric patients under MHD therapy showed a level of serum GAA similar to the other MHD patients. In the CRF rabbits, the renal GAA content was significantly lower than in the sham-operated rabbits and showed an inverse correlation with BUN. Renal GAT activity was also significantly lower in the CRF rabbits, showing a positive correlation with serum GAA concentration and an inverse correlation with BUN. These results indicate that renal GAT activity decreases as the BUN level rises in the course of renal damage, resulting in lower concentration of serum GAA in the uremic state; in a more advanced stage of renal failure, the inability of the kidney to synthesize GAA may be compensated by other organ(s). Some dialyzable substances which might inhibit renal GAT activity may also be present.