Acta Medica Okayama volume51 issue3

Malignant lymphoma was induced in Japanese (JWY), New Zealand (NZY) and Dutch (DUY) white rabbits by oral spray of cell-free pellets of culture fluid (crude virus fraction) of Ts-B6 cells (cynomolgus monkey B-lymphoblastoid cells harboring Epstein Barr virus-related simian herpesvirus or Cyno-EBV). Nine of 11 inoculated rabbits developed malignant lymphomas within 42-160 days after oral inoculation (JWY, 2/3; NZY, 5/6; DUY, 2/2). In contrast, none of the control rabbits inoculated in the same fashion with B95-8 (EBV-producing marmoset cell line) cell-free pellets developed malignant lymphoma. Most rabbits showed increased anti-VCA IgG and anti-EA-DR IgG antibody titers after inoculation by oral spray of Ts-B6 cell-free pellets. EBV-encoded RNA-1 was revealed in the tumor cells by in situ hybridization. EBV DNA was detected in the rabbit peripheral blood leukocytes (PBL) by polymerase chain reaction; the earliest positive result was obtained only two days after oral inoculation. These data suggest that orally administered Cyno-EBV in Ts-B6 cells infects PBL and then induces malignant lymphoma in rabbits. The availability of this animal model promises to clarify the role of EBV in human lymphoma and provides a means for studying prophylactic and therapeutic regimens.

A retrospective study on postoperative complications and factors affecting prognosis was performed on elderly patients with gastric cancer. We studied the correlation of age, pathological depth, preoperative laboratory data, physical status, duration of surgery, volume of blood loss, blood transfusion, curability, and extent of lymph node dissection to postoperative complications and prognosis in 47 patients with gastric cancer over 80 years old. Preoperative function of lung and liver frequently showed abnormal data. Postoperative complications were noted in 47% of patients, especially in the pulmonary system, liver and heart. Curability and extent of lymph node dissection were the significant factor affecting survival. Some mortalities caused by initial malignancy were recognized in the conservative lymph node dissection in the stage I . The incidence of postoperative complications was not significantly different according to extent of lymph node dissection. Blood transfusion was the only significant factor for the incidence of postoperative complication. The most frequent cause of death was the initial malignancy. We recommend that a low grade lymph node dissection should not be readily chosen for elderly patients in early cases.

 The aim of the study was to investigate whether Na⁺ channels play a role in the twitch component of the response of the isolated frog rectus abdominis to Ca²⁺-free Ringer solution with 0.2 mM Na₂EDTA by using tetrodotoxin and some other well known drugs that exhibit a blocking action on Na⁺ channels. In the presence of 5 x 10^-7 M tetrodotoxin, the twitch component, measured isotonically, disappeared. Although 10^-7 M d-tubocurarine was found to be ineffective, a complete blockage of twitch amplitude was observed at 5 x 10^-6 M concentration of the drug. The inhibitory action of d-tubocurarine on twitch response was not antagonized by 10^-6 and 10^-5 M carbachol. Propranolol (10^-6 - 10^-5 M), lidocaine (2 x 10^-6 - 10^-5 M), quinine (10^-6 - 2 x 10^-5 M) and quinidine (10^-6 - 2 x 10^-5 M) inhibited maximal twitch amplitude in a concentration dependent manner. These findings strongly suggest that activation of tetrodotoxin sensitive Na⁺ channel may play a primary role at twitch generation during exposure of the frog rectus abdominis to Ca²⁺-free Ringer solution with Na₂ EDTA.

Physiological strain plays an important role in maintaining the normal function and metabolism of bone cells. It is well known that the mineral content of astronauts' bones decreases during spaceflight. Thus, gravity is one of the important factors in the muscloskeletal system. The vector-free horizontal clinostat has been used to simulate conditions of microgravity for examining such effects on cells in culture. We analyzed the effects of simulated microgravity using a horizontal clinostat on cultured osteoblast-like cells (HuO9 cell line). Total cellular protein, which was measured as an indication of cell proliferation, was not significantly inhibited under simulated microgravity conditions. No morphological changes were detected under microgravity conditions by phase-contrast microscopy. However, the alkaline phosphatase (ALP) activity and osteocalcin production of the HuO9 cells decreased significantly under microgravity conditions. Our data indicate that simulated microgravity directly inhibits some differentiation phenotypes and some functions of osteoblasts. On the other hand, the addition of 1,25-dihydroxy-vitamin D₃ (1,25-(OH)₂-D₃) increased ALP activity under simulated microgravity conditions, although the total activity of ALP in the cells treated with 1,25-(OH)₂-D₃ was still lower under simulated microgravity conditions than that in the control cells. However, the cells under simulated microgravity conditions showed a greater enhancement of ALP activity by treatment with 1,25-(OH)₂-D₃.

Our aim was to study the effect of iron supplementation on the following aspects of erythrocyte metabolism in experimental hyperthyroidism: glutathione (GSH) levels, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activities. Hyperthyroidism induced by L-thyroxine administrations significantly raised erythrocyte GSH, GSH-Px and SOD levels of the rats (P < 0.001). Likewise, we observed that iron supplementation induced significant rises in erythrocyte GSH, GSH-Px and SOD levels (P < 0.001) as compared with the control group. The erythrocyte GSH, GSH-Px and SOD levels of hyperthyroidism-induced iron-supplemented animals were significantly higher when compared with either the iron-supplemented group (P < 0.001) or the only L-thyroxine-administered hyperthyroid group (P < 0.001, P < 0.05, P < 0.01, respectively). The results of this study show that L-thyroxine administration and/or iron supplementation increases GSH, GSH-Px and SOD levels of erythrocytes.

We studied 92 patients with allergic rhinitis in Syodoshima, Japan, during the pollen season between April and June to evaluate the cross-reactivity to different antigens, including pollen from the olive tree (Olea europaea) and orchard grass (Dactylis glomerata). Olive tree pollen was present in the atmosphere for 23 days, from May 19 to June 12, 1994. Specific IgE antibodies for olive tree pollen antigen were present in 21 (26.9%) of the 78 patients with allergic rhinitis. Nine (24.3%) of the 37 patients with allergic rhinitis exhibited positive skin reactivity to an extract of olive tree pollen. Fifteen (88.2 %) of the 17 patients who had IgE reactivity in their sera to olive tree pollen antigen demonstrated allergic reactions to an extract of olive tree pollen. Specific IgE antibodies for orchard grass pollen antigen were present in 43 (48.3%) of the 89 patients with allergic rhinitis and 20 (95.2%) of the 21 patients who had IgE reactivity in their sera to olive tree pollen antigen. The inhibition test using the CAP System revealed that the reactivity of the IgE antibody specific for olive tree pollen antigen was inhibited dose-dependently by an extract of orchard grass pollen. These findings show that there is a reaction in some patients with grass (Gramineae) pollinosis that might be induced by olive tree pollen.

We have established an Adriamycin (ADM) -resistant small cell lung cancer (SCLC) cell line, SBC-3/ADM100, which shows multifactorial mechanisms of resistance to ADM, such as overexpression of P-glycoprotein, an enhanced detoxifying system and a decrease in topoisomerase II activity. In the present study, we confirmed that SBC-3/ADM 100 showed collateral sensitivity to methotrexate and TNP-351, a new antifolate, though this cell line showed a typical multidrug resistance (MDR) pattern. We also demonstrated a faster uptake and higher accumulation (1.3-fold) of TNP-351 in the SBC-3/ADM100 cells than those in the parent SBC-3 cells. These results explain one of the mechanisms for collateral sensitivity in the resistant cells. Furthermore, this cell line was found to have no cross-resistance to edatrexate and minimal cross-resistance to trimetrexate, 254-S (cisplatin analog), 5-fluorouracil and 4-hydroperoxyifosfamide. These drugs will have clinical importance in patients with SCLC who were previously treated with an ADM-containing regimen. Thus, antifolates, especially TNP-351 and edatrexate, can be expected to eradicate residual multidrug resistant SCLC cells selected by ADM.

Sixty-seven trigger fingers of 58 idiopathic and hemodialysis patients were treated by percutaneous A1-pulley release technique. Severity of triggering was classified into five grades for treatment selection and prediction of possible results. Results were excellent in 41 fingers, good in 9, fair in 7, and poor in 10, requiring additional treatment. The results of the lower grades were better, and those of the higher grades were poor. Excellent or good results appeared to depend on the proper selection of the patients according to the grading system and confirmation of triggering disappearance just after the release. There were neither infections nor neuro-vascular deficits after treatment. Compared to conventional open release, this treatment was found to be more useful from the standpoints of ease and safety of the technique, and the patients' quick return to normal life.

We compared the transfection efficiency of four types of positively charged liposomes composed of (i) N-(α-trimethylammonioacetyl)-didodecyl-D-glutamate chloride (TMAG), dilauroylphosphatidylcholine (DLPC), and dioleoylphosphatidylethanolamine (DOPE) (1:2:2 molar ratio); (ii) 3β [N-(N′, N′-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and DOPE (3:2 molar ratio); (iii) dimethyldioctadecylammonium bromide (DDAB) and DOPE (1:2.2 molar ratio); (iv) N-[1-(2,3-dioleyloxy) propyl] -N,N,N-trimethylammonium chloride (DOTMA) and DOPE (1:1, w/w; lipofectin). Luciferase gene was used as a reporter gene. Among the cationic liposomes used, the liposomes composed of TMAG, DOPE and DLPC showed a much higher efficiency of plasmid DNA entrapment than the other cationic liposomes tested. In the absence of serum, the cationic multilamellar vesicles (MLV) and small unilamellar vesicles (SUV) composed of TMAG, DOPE and DLPC gave highly efficient transfection. On the other hand, MLV, dehydration-rehydration vesicles (DRV), and SUV liposomes prepared with the mixtures of DC-Chol and DOPE showed similar levels of transfection efficiency. However, the cationic liposomes composed of DDAB and DOPE showed inferior efficiency, whether in the form of DRV, SUV or MLV. The transfection efficiency of lipofectin was also low. In the presence of serum, on the other hand, a considerable (about 30-50%) amount of transfection activity was still observed at 10% fetal calf serum in the cationic MLV and SUV composed of TMAG, DOPE and DLPC. Cationic MLV, composed of TMAG, DOPE and DLPC, can transfect plasmid DNA, not only in the adherent cell lines but also in the suspension cell lines. These findings indicate that the transfection efficiency of cationic liposomes is affected by the lipid composition, the type of liposome, or the presence or absence of serum. They also indicate that the cationic liposomes containing TMAG, DOPE and DLPC are efficient vectors for gene transfer into cells.