Kimihiro Akagi

Purification and properties of alkaline ribonuclease from human serum

1. Five alkaline ribonucleases (EC 3.1.4.22) were purified about 140- to 1900-fold from human serum by phosphocellulose and DEAE-cellulose chromatographies and Sephadex G-75 filtration, with a total recovery of 22%. These were designated as RNAases 1-5. 2. Optimum activities were observed at pH 8.5-8.7 for RNAases 1-4, and at pH 7.5 for RNAase 5. The molecular weights of these enzymes were estimated by gel filtration as 45 000, 32 000, 20 000, 13 000 and 8500, respectively. 3. These RNAases were found to be heat-labile proteins but are markedly stabilized with bovine plasma albumin. The reaction was activated by Na+, K+, Mg2+ and Ca2+, and inhibited by Co2+, Fe2+, Cu2+ and Zn2+. EDTA had little effect on the velocity of the reaction. Spermine caused 2- to 7-fold activation. 4. Among the substrates examined, these RNAases preferentially hydrolyzed pyrimidine bodies and except for RNAase 5 had a higher affinity for poly(C) than poly(U) as substrate. Each enzyme was free from other nucleolytic enzymes and hydrolyzed only RNA.

Thyroid function in Yusho patients exposed to polychlorinated biphenyls (PCB)

Thyroid function was investigated in 123 yusho patients who were exposed to toxic levels of polychlorinated biphenyls (PCBs) 16 years ago. In yusho patients, compared with the patients without evidence of yusho or normal controls, the serum triiodothyronine (T3) and thyroxine (T4) levels were significantly higher, while thyroid stimulating hormone (TSH) levels measured by sensitive assay were normal. There was no difference in serum levels of albumin, alkaline phosphatase, total cholesterol, and thyroxine binding globulin (TBG) between the two groups and the prevalence of positive antithyroid autoantibodies was almost the same, suggesting that hyperthyroxinemia in yusho patients was not due to increased TBG binding or abnormal autoimmune mechanism. Serum free T4 levels, however, were not elevated, although T4/TBG ratio was significantly higher. The thyroid hormone levels were higher than normal value in 4 of 123 yusho patients but only 1 case had clinical symptoms such as excessive perspiration. Despite higher serum PCBs in yusho patients, there was no correlation between PCB levels and levels of T3, T4, or TSH. The present results suggest hyperthyroxinemia without obvious clinical symptoms in yusho patients long after exposure to PCBs.

Familial primary biliary cirrhosis associated with impaired concanavalin A-induced lymphocyte transformation in relatives

The familial occurrences of biochemical and immunological abnormalities and histocompatibility antigens were studied in 18 healthy first-degree relatives of patients with primary biliary cirrhosis (PBC) in two families. In each of these two families, there were two members who suffered from PBC. All relatives had normal serum aspartate aminotransferase, alkaline phosphatase, bilirubin, total cholesterol, and immunoglobulins except the two, who had a mild elevation of alkaline phosphatase without cholestasis. Autoantibodies were present in some relatives; five (28%) for antithyroglobulin antibody and antithyroid microsomal antibody, one (6%) for antimitochondrial and antinuclear antibody, and one (6%) for rheumatoid factor. Abnormalities of T or B lymphocytes in peripheral blood were detected in two (11%) relatives. Impairment of concanavalin A-induced lymphocyte transformation determined by ethidium bromide fluoroassay was found in seven (39%) relatives, although an abnormal response for phytohemagglutinin was detected in none of the relatives. The HLA haplotypes were not necessarily associated with positive autoantibodies or impaired concanavalin A-induced lymphocyte transformation in these families. These findings suggest that impairment of concanavalin A-inducible lymphocytes (mainly suppressor T cells) is one of the contributing factors in the development of PBC.

Effects of recombinant leukocyte interferon on serum immunoglobulin concentrations and lymphocyte subpopulations in chronic hepatitis B

To investigate immune effects of interferon (IFN) therapy in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, serum immunoglobulin concentrations and peripheral lymphocyte subpopulations were sequentially studied before, during, and after therapy in nine patients who were treated with recombinant human α-IFN in doses ranging from 3 to 10 million units per day for 28 days. Serum immunoglobulin A levels decreased significantly, from 414±23 mg/dl (mean ± SE) to 379±28 mg/dl (P<0.05), after the first week of therapy and to a bottom value of 323±20 mg/dl (P<0.001) at the fourth week. Immunoglobulin G levels decreased significantly, from 2603±175 to 2328±169 mg/dl (P<0.005), after the first week of therapy and to a bottom value of 2005±199 mg/dl (P<0.001) at the fourth week. Immunoglobulin M levels were also reduced significantly after 3 weeks of therapy (from 229±23 to 188±15 mg/dl;P<0.01). These reductions in immunoglobulins A, G, and M returned to pretreatment levels by 4 months after the end of the therapy. In lymphocyte subpopulations, significant depressions were found in CD3-, CD4-, CD8-, and B1-positive cells in peripheral blood after the first week of therapy (CD3, from 1700±114 to 1234±114/mm3,P<0.005; CD4, from 1036±88 to 780±64/mm3,P<0.005; CD8, from 620±57 to 426±60/mm3,P<0.05; and B1, from 519±84 to 276±48/mm3,P<0.01) followed during therapy, while Leul la-positive cells did not change significantly. During the 6-month follow-up period, three patients had a sustained clinical remission in which HBeAg disappeared from serum. Disappearance of HBeAg was unassociated with initial levels or percentage changes of serum immunoglobulins and peripheral lymphocytes expressing each of the test markers in these patients. These findings suggest that immune effects of IFN therapy are independent from its antiviral effects.

Purification and properties of urinary alkaline ribonucleases from patients with nephrotic syndrome

Four urinary alkaline ribonucleases (RNase, EC 3.1.4.22) were purified from patients with nephrotic syndrome using phosphocellulose, DEAE-cellulose and Sephadex G-75 chromatographiy. These enzymes were designated as RNases 1--4, respectively, in order of elution on phosphocellulose chromatography. The respective purification of each fraction was 41-, 23-, 34- and 27-fold with a total recovery of 25%. The pH optima of these RNases were around 8.5 with Tris/HCl buffer and the reaction was activated by mono- and divalent cations, such as Na+, K+, Mg2+ and Ca2+, but inhibited by Fe2+, Cu2+ and Zn2+. EDTA had little effect on the velocity of reaction. The molecular weights of RNases 1--4 were estimated by gel filtration as 45 000, 32 000, 20 000, and 13 000, respectively. Each enzyme hydrolyzed pyrimidine nucleotides preferentially with higher affinity for poly(C) than poly (U) as determined with synthetic polymers and was free from other nucleolytic enzymes. The patients with renal disorders excreted one to four RNases in urine and the number of enzymes increased as the concentration of urinary protein increased. On the other hand, normal subjects excreted a single fraction essentially identical to RNase 1.

Ileal perforation in diffuse intestinal Behçet disease: Report of a case

Abstract Intestinal ulcers in Behçet disease tend to cause perforation, and postoperative recurrence is common with a high mortality rate. The optimal therapeutic strategy has yet to be elucidated, particularly in cases of diffuse intestinal involvement. We herein present a case of diffuse intestinal Behçet disease with ileal perforation. A 57-year-old Japanese woman was referred to our institution with complaints of intractable oral ulcers and abdominal pain. The patient underwent an emergency laparotomy for perforated peritonitis in spite of the intravenous administration of prednisolone (1.5 mg/kg) under total parenteral nutrition. Macroscopically, an inflamed ileum measuring 1.6 m in length was resected, including a 1-cm perforated ulceration. Innumerable small and deep ulcers were also observed, consisting of nonspecific inflammation. The patient has been free from any recurrence of intestinal ulcers while being treated with prednisolone, colchicine, and a low-residue diet for 1.5 years.

Low activity of gamma-glutamyl transpeptidase in serum of acute intrahepatic cholestasis

Low gamma-glutamyl transpeptidase (gamma-GTP) activity in serum was observed in 11 patients with acute intrahepatic cholestasis (cholestatic hepatitis and fulminant hepatitis), despite a marked increase in bilirubin levels. Inhibitors of gamma-GTP were not detected in sera of these patients. Their gamma-GTP levels in the liver were significantly higher than those in chronic liver diseases. An electrophoretic study of liver gamma-GTP in acute intrahepatic cholestasis showed the same mobility as in chronic liver diseases. These results suggest that the low serum gamma-GTP activity in acute intrahepatic cholestasis is due to factors inhibiting the release of the enzyme from the liver.

Fatal colorectal cancer in juvenile polyposis syndrome

The patient was admitted to Kyushu Central Hospital at the age of 22 years because of abdominal pain and iron-deficiency anemia (hemoglobin level, 7.4g/dl). He had neither congenital deformity nor a family history of gastrointestinal carcinomas. Gastrointestinal investigations revealed a few tiny gastric polyps and nine colorectal polyps, measuring up to 4cm in diameter. A barium meal follow-through study showed no abnormality in the small intestine. Histologic examination of biopsy specimens taken from the gastric polyps demonstrated mild foveolar hyperplasia in relatively abundant stroma. Six colonic polyps, each more than 1cm in diameter, were removed by endoscopic polypectomy with a cautery snare, as described in a previous report.1 All of the resected polyps were histologically consistent with typical juvenile polyp. The largest pedunculated polyp

Efficasy of partial splenic embolization for the treatment of liver cirrhosis with hypersplenism: A case report.

症例は57歳女性,肝硬変で外来通院中に肝機能が低下し,腹水を認めたため入院した.脾機能亢進(巨大脾腫,汎血球減少)を伴う非代償性肝硬変と診断し,その治療として部分脾動脈塞栓療法(以下SE)を施行した.脾梗塞率は90%であった.SE術後,末梢血球数が増加したのみでなく,肝機能の著明な改善(Child CからA)が見られ,術後1年半後には,CT上で測定された肝容積は術前640cm3から780cm3に増加した.また,術前脾門部の3ヵ所に径1-1.5cmの脾動脈瘤が認められたが,術後3ヵ月には2ヵ所は縮小し,1ヵ所は血栓化し消失した.SEは肝硬変患者の脾機能亢進による汎血球減少のみでなく,肝機能の改善が期待される有用な治療法と考えられる.さらに,脾動脈瘤の治療としても有用である可能性が示唆された.