Subordination stress in Nile tilapia and its effect on plasma lysozyme activity

Dominant Nile tilapia had significantly higher lysozyme activity than did subordinate fishes (α=0·05). Plasma lysozyme level was not correlated with sex, parental origin, rearing length, weight, condition factor or rearing density.     

Effect of nickel on oxygen free radical metabolism

The effect of nickel on superoxide dismutase activity (SOD), as well as on rate of hydroxydopamine oxidation, was studied in vitro since lipid peroxidation has been implicated in cell damage by nickel, whose toxicity and carcinogenicity are well established. Nickel strongly inhibits SOD activity. The degree of inhibition is directly proportion to the nickel concentration (tested range 0.066 to 0.33 microgram/mL in the reaction mixture); to the substrate concentration (tested range 0.4 x 10 4M to 1.1 x 10 4M 6-hydroxydopamine); and to reaction mixture. Autoxidation of 6-hydroxydopamine was increased by nickel concentrations higher than 15 micrograms/mL. The combination of excessive oxygen free radical production and inhibition of their elimination by inhibition of SOD activity may contribute to the nickel toxicity that has been reported in industrial accidents, as well as to the high incidence of cancer occurring in nickel workers. It may also contribute to many complications in uremic patients, in whom increased serum nickel levels were reported to be in a similar range to those inhibiting SOD.     

Gastroscopic evaluation of anti-inflammatory agents

Gastroscopy was performed in 164 patients with rheumatoid arthritis (RA) and 85 with osteoarthritis (OA) to assess the effects of anti-inflammatory agents on the stomach. The main criterion for entry into the trial was the absence of active gastric lesions on pretreatment endoscopy. The patients were divided into groups to receive one of 12 anti-inflammatory drugs or combinations of these. Gastroscopy repeated at three to six and at 12 months disclosed gastric lesions in 78 cases (31%), patients in both disease categories being similarly affected. Lesions occurred in 41 of the 177 patients (23%) receiving a single drug and in 37 of the 72 (51%) receiving combined treatment. All the anti-inflammatory drugs caused gastric damage, the greatest offender being aspirin (13 out of 26 patients) and the least sulindac and diflunisal (two out of 19 (11%) and two out of 20 (10%) patients respectively). Corticosteroids caused gastric damage in only three out of 21 patients (14%), a lower incidence than expected.The indiscriminate prescribing of anti-inflammatory drugs to patients with OA is to be deplored. A lack of correlation between the patients'' subjective complaints of gastric discomfort and the gastroscopic findings emphasises the unreliability of patients'' complaints and the importance of gastroscopy in assessing gastric tolerance. It was not possible to assess minimal prescribing doses or minimum periods of treatment below which gastric damage may be guaranteed not to occur.     

Regulation of protein synthesis by estradiol-17beta in cultured hepatocytes

Estradiol-17beta added to cultured chick embryo hepatocytes induced the appearance in the medium of a phosphoprotein, identified as phosvitin on the basis of: (i) its behaviour on ionic exchange columns; (ii) its SDS-acrylamide gel electrophoretic mobility; (iii) its amino acid composition. The hormone treatment was also followed by a decreased synthesis of other proteins secreted by the hepatocytes.     

Bevacizumab Treatment for Meningiomas in NF2: A Retrospective Analysis of 15 Patients

Bevacizumab treatment can result in tumor shrinkage of progressive vestibular schwannomas in some neurofibromatosis 2 (NF2) patients but its effect on meningiomas has not been defined.To determine the clinical activity of bevacizumab against NF2-related meningiomas, we measured changes in volume of meningiomas in NF2 patients who received bevacizumab for treatment of progressive vestibular schwannomas. A radiographic response was defined as a 20% decrease in tumor size by volumetric MRI analysis. In addition, we determined the expression pattern of growth factors associated with tumor angiogenesis in paraffin-embedded tissues from 26 unrelated meningiomas. A total of 48 meningiomas in 15 NF2 patients were included in this study with a median follow up time of 18 months. A volumetric radiographic response was seen in 29% of the meningiomas (14/48). Tumor shrinkage was not durable: the median duration of response was 3.7 months and the median time to progression was 15 months. There was no significant correlation between pre-treatment growth rate and meningioma response in regression models. Tissue analysis showed no correlation between tumor microvascular density and expression of VEGF pathway components. This data suggests that, in contrast to schwannomas, activation of VEGF pathway is not the primary driver of angiogenesis in meningiomas. Our results suggest that a minority of NF2-associated meningiomas shrink during bevacizumab therapy and that these responses were of short duration. These results are comparable to previous studies of bevacizumab in sporadic meningiomas.     

Natural antibodies to interferon-gamma

Natural antibodies to interferon (IFN)-γ were detected in the serum of virus-infected patients and also, at a low titre, in the serum of healthy subjects. The increased titre of antibodies to IFN-γ in the sera of virus-infected patients, and its decrease with clinical resolution, indicate that these antibodies are related to viral infection and probably reflect IFN-γ production as a result of antigenic stimulationin vivo. Natural antibodies to IFN-γ were affinity purified and studied for their capability to interferein vitro with the multiple activities of the lymphokine. Data obtained show that these human anti-IFN-γ antibodies have no inhibitory effect on the antiviral and antiproliferative activity of IFN-γ and do not interfere with the binding of the lymphokine to its specific cell receptor. Instead, they can inhibit the expression of HLA-DR antigens induced by IFN-γ on U937 cells and interfere, in mixed lymphocyte culture, with the proliferation of lymphocytes and the generation of cytotoxic lymphocytes. Experiments in animal models suggest that natural antibodies to IFN-γ may have a role in the immunoregulatory process limiting the intensity and/or duration of immune response. As they can interfere only with the immunomodulating activities of IFN-γ, these antibodies might open up new therapeutic approaches to diseases with evidence of activated cell-mediated immunity.     

Oribatid mites reveal that competition for resources and trophic structure combine to regulate the assembly of diverse soil animal communities

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