Phase transitions of iron-nitride magnetic fluids.

Phase transitions of magnetic fluids in the zero field were studied from the viewpoint of static susceptibility and typical relaxation time in order to distinguish between the transitions and the blocking phenomena. We used iron-nitride magnetic fluids containing nearly uniform particles so as to remove the effects of particle-size distribution. In the densest sample, we observed the growth of ferromagnetic fluctuations and, in the diluted samples, a temperature-induced first-order phase transition.

Secondary aortoduodenal fistula complicating aortic grafting, as a cause of intermittent chronic intestinal bleeding.

Intermittent intestinal bleeding persisted in a 77-year-old male, who had undergone grafting for abdominal aortic aneurysm. Each attack lasted for a few weeks and spontaneously resolved. Only a minute abnormality was found in the third portion of the duodenum; barium studies showed a segmental narrowing, but endoscopy disclosed only a small erosion in that portion. Massive and fatal gastrointestinal hemorrhage broke out 6 months after the onset of bleeding. Autopsy revealed an adhesion area with a small fistula formation between the duodenum and aorta. Even slight endoscopic findings should be considered suggestive of aortoenteric fistula in patients after aortic surgery.

Follicular dendritic cell tumor with histiocytic characteristics and fibroblastic antigen.

A report is presented of a follicular dendritic cell (FDC) tumor arising in the lymph nodes and inguen of a 55-year-old Japanese female, who had suffered from schizophrenia for 25 years. The left submandibular lymph nodes had completely lost their normal architecture, except for the capsule, due to tumor cell infiltration. Occasional nodular structures resembling epithelioid granulomas, attributable, at least in part, to follicular involvement of tumor cells, were observed. These nodules were composed of epithelioid- or fibroblast-like tumor cells forming interwoven fascicles, to which small lymphocytes were attached. Tumor cells were also scattered in the internodular areas. For more atypical tumor cells, arranged in a sheet-like structure, were present in the inguinal specimen, the tumor cells of which expressed Ki-M4p, CD21, CD35 and other antigens known to be expressed on FDC. Furthermore, they also expressed the monocyte/macrophage antigens, alpha 1-antitrypsin, alpha 1-antichymotrypsin, lysozyme, CD14, CD33, CD68 and Mac387 and fibroblastic antigen. Ultrastructural studies demonstrated lysosomal granules as well as a few desmosomes, indicating the tumor cells possessed fibrohistiocytic and FDC characteristics.

[Secondary non-Hodgkin lymphoma of the prostate: a case report].

A 72-year-old man presenting with difficulty of urination, was diagnosed with benign prostatic hyperplasia and transurethral resection of prostate (TUR-P) was performed. However, pathological diagnosis of 40% of the TUR-specimen was of malignant lymphoma. Immunohistochemical examination revealed B-cell origin, diffuse and medium-cell type, according to the LSG classification. Then we performed chemotherapy with a combination of cyclophosphamide, adriamycin, vincristine and prednisolone. Trans-rectal biopsy specimens of the prostate after 3 courses of chemotherapy, revealed no cells of malignant lymphoma.

Mechanisms of corticosteroid action in immune thrombocytopenic purpura (ITP): experimental studies using ITP-prone mice, (NZW x BXSB) F1.

To determine the mechanism by which platelet counts increase after corticosteroid therapy for human immune thrombocytopenic purpura (ITP), we studied the platelet kinetics using prednisolone (PDN)-treated ITP-prone mice, (NZW x BXSB) F1 (W/B F1). An increase in platelet counts was observed in W/B F1 mice (n = 10, mean +/- SD, 1,202 +/- 202 x 10(3)/microL) 4 weeks after treatment with PDN (2 mg/kg/d); no increase occurred in nontreated W/B F1 mice (n = 5,651 +/- 126, P less than .005). Prolonged platelet life-spans (PLSs) were observed in treated W/B F1 mice (1.29 +/- 0.40 days), but not in nontreated controls (0.60 +/- 0.24 days, P less than .01). No increase in platelet production (platelet turnover) was found in PDN-treated W/B F1 mice, but significant decreases in platelet-associated antibodies (PAAs) and platelet-bindable serum antibodies (PBAs) were noted. Studies on organ localization of radiolabeled platelets showed that hepatic uptake significantly decreased in the treated W/B F1 mice, but not in nontreated W/B F1 mice. To elucidate the effect of PDN on the reticulo-endothelial phagocytic activity in W/B F1 mice, we studied in vivo clearance of IgG-sensitized, 51Cr-labeled autologous erythrocytes. W/B F1 mice treated with PDN showed a marked impairment of their ability to clear these cells, although PDN had little effect on the number of splenic or hepatic macrophage Fc gamma receptors. These results and our previous findings of splenectomy suggest that PDN improves platelet counts not only by suppressing systemic reticulo-endothelial phagocytic function but also by reducing antibody production.

[Acute myelogenous leukemia accompanied by HTLV-I associated myelopathy (HAM) caused by blood transfusion].

A case of AML accompanied by HTLV-I associated myelopathy (HAM) is reported. A 37-year-old woman was admitted to our hospital in April 1985 because of severe anemia, general malaise and fever. On admission, anemia, thrombocytopenia and leukocytosis consisting of 32% myeloblasts and 6% promyelocytes were noted. A bone marrow study revealed marked myeloid hyperplasia, and a diagnosis of acute myelogenous leukemia (M2) was made. In order to improve the patient's severe anemia and thrombocytopenia, a large amount of blood transfusion was applied at once. Thereafter BHAC-DMP therapy was commenced resulting in complete remission 3 months after initiating chemotherapy. Hematological improvement has continued (as of May 1988). In June 1986 the patient showed a gait disturbance of slowly progressive course. Neurological examination revealed hyperactive knee and ankle jerks with a positive Babinski's sign, and foot clonus were also noted bilaterally. Sphincter impairment was detected. A CSF sample contained slight pleocytosis with some abnormal lymphocytes similar to those found in adult T cell leukemia. Antibodies to HTLV-I were found in the CSF and serum by EIA method. According to these findings we diagnosed the patient's illness as HAM, referring to the new clinical entity named by Osame. This patient had undergone a blood transfusion 14 months before the onset of this myelopathy, therefore the transmission of exogenous antigens through blood transfusion may be the cause of HAM. Corticosteroid pulse treatment was administered and striking improvements countering gait disturbance resulted in this patient.