Conventional and extended intramammary therapy of persistent subclinical mastitis using nafcillin-penicillin- dihydrostreptomycin in lactating dairy cattle

Summary The objective of the present study was to compare the efficacy of conventional and extended intramammary (IMM) therapy of persistent subclinical mastitis in lactating dairy cattle using nafcillinpenicillin-dihydrostreptomycin combination (NPD). Sixty-five dairy cows with 126 infected quarters were enrolled in the study. Infected cows were allocated randomly to 1 of 3 different treatment regimens: (1) conventional group: NPD administered IMM 3 times at 24-h intervals (20 infected cows, 43 intramammary infections [IMI]), (2) extended group: NPD administered IMM 6 times at 24-h intervals (23 cows, 43 IMI), and (3) untreated control group (22 cows, 40 IMI). The overall bacteriological cure (BC) rates for subclinical IMI were 86.04%, 100%, and 20% for the conventional, extended and the control groups, respectively; indicating a higher BC rate (P<0.0001) for the treated groups than the control group. Significant difference (P=0.029) concerning the BC rate was also observed between the extended and the conventional groups. Significant difference (P=0.0021) in somatic cell count (SCC) was detected between the extended and the control group. Fat percentage increased in the conventional (P=0.029) and in the extended (P<0.0001) groups, and protein percentage increased only in the extended group (P=0.0016). There was no significant difference in posttreatment milk production between the groups (P>0.05). Results of this study indicate that NPD therapy was effective in eliminating subclinical IMI in lactating dairy cows, and that extended therapy enhanced BC rate and reduced SCC

Chromosomes are target sites for photodynamic therapy as demonstrated by subcellular laser microirradiation.

The present investigation has been undertaken to examine the possibility that the cell nucleus, and specifically the genetic material, is a target site for photodynamic therapy. PTK2 and Hep-2 cells are pretreated with a medium containing 15 microg/ml (0.09 mM) 5-aminolevulinic acid (ALA). Individual fluorescence images are recorded for each selected cell using a cooled charge-coupled device (CCD). A laser microbeam system generating 630 nm is used for subcellular-region irradiation of specific targets: chromosomes, the mitotic spindle, the perispindle region and the peripheral cytoplasm. Nuclei of interphase cells are also irradiated. Data comparing the sensitivities of the different subcellular microirradiation sites in ALA-treated mitotic cells demonstrate that under the irradiation conditions used, the chromosome is the most sensitive subcellular target followed by the perispindle region, the peripheral cytoplasm and spindle, and, lastly, the interphase nucleus

Chromosomes are target sites for photodynamic therapy as demonstrated by subcellular laser microirradiation.

The present investigation has been undertaken to examine the possibility that the cell nucleus, and specifically the genetic material, is a target site for photodynamic therapy. PTK2 and Hep-2 cells are pretreated with a medium containing 15 microg/ml (0.09 mM) 5-aminolevulinic acid (ALA). Individual fluorescence images are recorded for each selected cell using a cooled charge-coupled device (CCD). A laser microbeam system generating 630 nm is used for subcellular-region irradiation of specific targets: chromosomes, the mitotic spindle, the perispindle region and the peripheral cytoplasm. Nuclei of interphase cells are also irradiated. Data comparing the sensitivities of the different subcellular microirradiation sites in ALA-treated mitotic cells demonstrate that under the irradiation conditions used, the chromosome is the most sensitive subcellular target followed by the perispindle region, the peripheral cytoplasm and spindle, and, lastly, the interphase nucleus