Persistence of the activity of topical ivermectin against biting lice (Bovicola bovis)

To assess the persistence of the activity of topical ivermectin against a natural challenge with biting lice (Bovicola bovis), 90 mixed-breed cattle that had been treated to remove lice, were blocked by bodyweight within sex and randomly allocated to three treatments: untreated control, doramectin at 200 micrograms/kg by subcutaneous injection, and ivermectin at 500 micrograms/kg by topical application. Forty-five pens were blocked into three groups of 15, and the blocks of pens were randomly allocated to three 14-day challenge periods starting 21, 28 and 35 days after treatment. There were five pens per treatment for each challenge period, and one B bovis-infested donor calf was introduced into each pen containing two principal calves at the start of the challenge period for that block of pens. The calves were examined thoroughly for B bovis seven, 14 and 21 days after the introduction of the donors. There were no significant differences between the control and doramectin groups for the numbers of animals infested, or the geometric mean louse counts at the final examination for any of the challenge periods. At the final examination for each challenge period, the louse counts of the cattle treated with topical ivermectin were all zero, and significantly (P < 0.05) fewer cattle treated with topical ivermectin were infested than either the controls or cattle treated with doramectin.     

Multiple roles of interferon-gamma in the mediation of interleukin 12-induced tumor regression

Administration of recombinant interleukin 12 (IL-12) induces tumor regression that is associated with T-cell infiltration in the OV-HM ovarian carcinoma and CSA1M fibrosarcoma models. After confirming the blocking of regression by injection of anti-IFN-gamma monoclonal antibody (mAb), we investigated the mechanisms underlying the requirement of IFN-gamma in T-cell migration and tumor regression. T-cell migration was inhibited by injection of anti-IFN-gamma mAb to OV-HM tumor-bearing mice prior to IL-12 treatment. We examined, using the lymphoid cell migration assay, whether IFN-gamma is required for enhancing the migratory capacity of T cells or the T cell-accepting potential of tumor masses during IL-12 treatment. Spleen cells from IL-12-treated or untreated OV-HM-bearing mice were stained in vitro with a fluorescein chemical and transferred i.v. into OV-HM-bearing mice that were not treated with IL-12. Migration of donor cells was quantitated by counting the number of fluorescent cells on cryostat sections of tumor masses from recipient mice. Compared to spleen cells from OV-HM-bearing mice that were not treated with IL-12, enhanced migration was observed for cells from IL-12-treated OV-HM-bearing mice. Anti-IFN-gamma pretreatment of donor mice before IL-12 treatment did not reduce the migratory capacity of T cells, whereas migration was markedly inhibited in recipient mice injected with anti-IFN-gamma. Anti-IFN-gamma pretreatment decreased vascular cell adhesion molecule-1 (VCAM-1)-/intercellular adhesion molecule-1 (ICAM-1)-positive blood vessels at tumor sites. Consistent with this, migration was also inhibited by treatment of recipient mice with either anti-VCAM-1 or anti-ICAM-1 mAb. In contrast to the OV-HM model, T-cell migration was not affected in the CSA1M model following preinjection of anti-IFN-gamma mAb. In this model, VCAM-1-/ICAM-1-positive blood vessels existed even after anti-IFN-gamma treatment, although tumor regression was completely inhibited. These results indicate that IFN-gamma plays two distinct roles in expressing the antitumor efficacy of IL-12: one is to support the T-cell acceptability of tumor masses, and the other is to mediate the antitumor effects of migrated T cells.     

Bacterial and human cell mutagenicity study of some C18H10 cyclopenta-fused polycyclic aromatic hydrocarbons associated with fossil fuels combustion

Maximal activity of NADP.H-cytochrome c reductase was found in the liver, the lowest one--in the retina. On the contrary, the highest activity of aldose reductase was observed in the retina, the lowest one--in the liver. The activity of NADP.H-cytochrome c reductase in the retina of rats with hereditary degeneration of the retina increased to the 60th day of postnatal life by 33%, the increase reaching 273% to the 90th day. In the brain cortex, the increase in the activity to the 45-60th days amounted to 22-34%, whereas at the age of 90 days the difference between healthy and patient rats, as well as the difference between males and females became less significant. The activity of aldose reductase in the cortex and retina in patient rats at the 20th day was 35% lower than in healthy animals. In the liver of patient rats, to the age of 45 days, the activity of aldose reductase decreased by 38%. At other periods, no significant differences were observed between healthy and patient animals with respect to the activity of this enzyme.     

Impact of scale standardization on images of digital radiography systems

OBJECTIVES: To test the effect of altering image size on diagnostic quality. METHODS: Endodontic files, size 10 and 15 were prepared to full root length and 1.5 mm short, in upper and lower molars and premolars. Digital images of the Sidexis (S) and Visualix/Vixa (V) system were reduced in size to Digora (D) scale, and the D images were enlarged to S scale. ROC analysis was performed and data analysed with MANOVA statistics. RESULTS: Assessment of root canal length with file size 10 was less accurate for the S images reduced in size, compared with the original S images (P < 0.011). All other differences were not significant (P > 0.081). CONCLUSIONS: Relevant diagnostic information may be lost when images are reduced in size. Therefore, for optimal presentation, the smaller images should be enlarged rather than the larger ones reduced.     

Management of a maxillary canine with dens invaginatus and a vital pulp

A case is presented that demonstrates successful management of a maxillary canine with dens invaginatus (Oehlers' type 3 invagination) with associated chronic periradicular periodontitis and a vital pulp. Debridement and obturation of the invaginated space resulted in resolution of the associated periradicular radiolucency. Pulp vitality was retained after endodontic treatment of the invagination.