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The distribution of T. gondii in commercial cuts of pork (ham, tenderloin, spareribs and arm picnic) by PCR and bioassay from experimentally infected pigs, was evaluated. Eighteen mixed breed pigs were divided into two groups (G). The G1 animals (n=10) were infected with 4 x10 4 oocysts of the T. gondii VEG strain and the G2 animals (n=8) were used as control. Pigs of both groups were slaughtered at 59 th day after infection, and meat samples were collected for bioassay and PCR. All animals from G1 were positive by at least one or both tests, and all control animals were negative. T. gondii was identified in pork by mouse bioassay and PCR in 27/40 (67.5%) and in 9/40 (22.5%) of the evaluated samples, respectively. There were no statistical differences in the distribution of tissue cysts from commercial cuts of pork by bioassay (P>0.05). However, statistical differences were observed when mouse bioassay and PCR were compared (P<0.01). Keywords: pork meat, mouse bioassay, PCR, Toxoplasma gondii RESUMO Avaliou-se a presença de T. gondii em cortes comerciais de carne suína (pernil, lombo, costela e paleta), por meio do bioensaio e PCR, em animais experimentalmente inoculados. Dois grupos (G) foram formados. Os animais do G1 (n=10) foram inoculados com 4 x10 4 oocistos da cepa VEG e os do G2 (n=8) permaneceram como grupo-controle, não inoculado. Todos os animais foram abatidos no dia

In previous work, sustained levels of circulating human growth hormone (hGH) and a highly significant weight increase were observed after electrotransfer of naked plasmid DNA (hGH-DNA) into the muscle of immunodeficient dwarf mice (lit/scid). In the present study, the efficacy of this in vivo gene therapy strategy is compared to daily injections (5 μg/twice a day) of recombinant hGH (r-hGH) protein, as assessed on the basis of several growth parameters. The slopes of the two growth curves were found to be similar (P > 0.05): 0.095 g/mouse/d for protein and 0.094 g/mouse/d for DNA injection. In contrast, the weight increases averaged 35.5% (P < 0.001) and 23.1% (P < 0.01) for protein and DNA administration, respectively, a difference possibly related to the electroporation methodology. The nose-to-tail linear growth increases were 15% and 9.6% for the protein and DNA treatments, respectively, but mouse insulin-like growth factor I (mIGF-I) showed a greater increase over the control with DNA (5- to 7-fold) than with protein (3- to 4-fold) administration. The weight increases of several organs and tissues (kidneys, spleen, liver, heart, quadriceps and gastrocnemius muscles) were 1.3- to 4.6-fold greater for protein than for DNA administration, which gave a generally more proportional growth. Glucose levels were apparently unaffected, suggesting the absence of effects on glucose tolerance. A gene transfer strategy based on a single hGH-DNA administration thus appears to be comparable to repeated hormone injections for promoting growth and may represent a feasible alternative for the treatment of growth hormone deficiency.

No abstract

This study investigated to what extent a single exposure to low doses of ionizing radiation can induce genotoxic damage in irradiated adult zebrafish (Danio rerio) and its non-irradiated F1 progeny. Four groups of adult zebrafish were irradiated with a single dose of X-rays at 0 (control), 100, 500 and 1000 mGy, respectively, and couples of each group were allowed to reproduce following irradiation. Blood of parental fish and whole-body offspring were analysed by the comet assay for detection of DNA damage. The level of DNA damage in irradiated parental fish increased in a radiation dose-dependent manner at day 1 post-irradiation, but returned to the control level thereafter. The level of DNA damage in the progeny was directly correlated with the parental irradiation dose. Results highlight the genotoxic risk of a single exposure to low-dose ionizing radiation in irradiated individuals and also in its non-irradiated progeny.

No abstract

Micronucleus (MN) assay constitutes a valuable surrogate to the chromosome aberration technique for in vitro testing of the genotoxicity of substances. As test substances, two peptidic compounds (DOTATATE and Ubiquicidin) used in nuclear medicine, were tested for in vitro cytotoxicity and genotoxicity in CHO-K1 cells. None of the compounds showed detectable cytotoxicity (0.5-7.3 ng/mL for DOTATATE and 0.3-4.5 ng/mL for UBI), genotoxicity (0.72, 7.2 and 72.0 ng/ml for DOTATATE and 0.45, 4.5 and 45.0 ng/mL for UBI) or cell cycle changes as compared to untreated controls at the concentrations tested. Statistical analysis showed good concordance between two independent analysts. The results corroborate the notion of the safety of the compounds and present improvements of the in vitro MN assay when performed in a pre-clinical trial context that increase the throughput of small-to-medium testing facilities as an alternative to high content screening systems.

These results show that hGH-DNA administration into non-exposed tibialis muscle followed by the new HV/LV electrotransfer protocol was an equally efficient, less traumatic treatment, much more suitable for pre-clinical testing than administration into exposed quadriceps.