Contagem total e diferencial dos leucócitos presentes no leite de cabras sadias utilizando-se a coloração de verde de metil e pironina e a citocentrifugação / Total and differential leukocyte counts in the milk of healthy goats, using methyl green-pyronin stain and cytocentrifugation

As particularidades da secreção láctea do tipo apócrina, na espécie caprina, tornam necessárias técnicas específicas para a determinação da quantidade e da qualidade das células presentes no leite desta espécie. Dentre estas particularidades, pode-se citar a presença dos corpúsculos citoplasmáticos. De acordo com estas características, o objetivo do presente trabalho foi determinar a contagem total de leucócitos no leite de cabras sadias, por meio da contagem microscópica direta com verde de metil e pironina-Y, e a contagem celular automática por citometria de fluxo, assim como determinar os tipos leucocitários, através da técnica de citocentrifugação. Foram analisadas 102 de leite de cabras sadias, das raças Saanen, Parda Alpina e Toggenburg. O valor mediano obtido pela contagem microscópica direta e automática foi de 142.840 e 406.000 células somáticas/mL de leite, respectivamente. Os valores médios obtidos na citocentrifugação foram de 73,24 ± 18,35% de neutrófilos, 3,55 ± 3,06% de linfócitos e 24,33 ± 18,89% de monócitos e células epiteliais. De acordo com os resultados, pode-se concluir que o valor obtido pela coloração de verde de metil e pironina-Y é significativamente menor, sendo um importante método para a determinação da celularidade presente no leite de cabras, pois exclui os corpúsculos citoplasmáticos característicos desta espécie.

The characteristics of the apocrine milk secretion observed in goats make it necessary to use specific techniques to determine the quantity and quality of cells found in this kind of milk. Among these characteristics is the presence of cytoplasmic bodies. The objective of the present study was to determine total leukocyte counts in the milk of healthy goats using direct microscopy and methyl green-pyronin Y and automatic cell count by flow cytometry as well as to determine leukocyte types by means of cytocentrifugation. A total of 102 milk samples from healthy Saanen, Brown Alpine and Toggenburg goats were analyzed. The median value of direct microscopic and automatic counts was 142,840 and 406,000 somatic cells/mL of milk, and mean values obtained in cytocentrifugation were 73.24 ± 18.35% neutrophils, 3.55 ± 3.06% lymphocytes and 24.33 ± 18.89% monocytes and epithelial cells. According to the results obtained, it was concluded that methyl green-pyronin Y is an important method, perhaps the most precise one, for determining cell counts in goat milk, because it excludes cytoplasmic bodies. Moreover, the different cell types found in milk are important defenses of the mammary gland against mastitis-causing pathogens.

Bone formation following implantation of titanium sponge rods into humeral osteotomies in dogs: a histological and histometrical study.

BACKGROUND: Titanium (Ti) is widely proven to enhance bone contact and growth on its surface. It is expected that bone defects could benefit from Ti to promote healing and to increase strength of the implanted area. PURPOSE: The present study aimed at comparing the potential of porous Ti sponge rods with synthetic hydroxyapatite (HA) for the healing of bone defects in a canine model. MATERIAL AND METHODS: Six mongrel dogs were submitted to three trephined osteotomies of 6.0 x 4.0 mm in one humerus and after 2 months another three osteotomies were performed in the contralateral humerus. A total of 36 defects were randomly filled either with Ti foam, particulate HA, or coagulum (control). The six animals were killed 4 months after the first surgery for histological and histometrical analysis. RESULTS: The Ti-foam surface was frequently found in intimate contact with new bone especially at the defect walls. Control sites showed higher amounts of newly formed bone at 2 months - Ti (p = 0.000) and HA (p = 0.009) - and 4 months when compared with Ti (p = 0.001). Differently from HA, the Ti foam was densely distributed across the defect area which rendered less space for bone growth in the latter's sites. The use of Ti foams or HA resulted in similar amounts of bone formation in both time intervals. Nevertheless, the presence of a Ti-foam rod preserved defect's marginal bone height as compared with control groups. Also, the Ti-foam group showed a more mature bone pattern at 4 months than HA sites. CONCLUSION: The Ti foam exhibited good biocompatibility, and its application resulted in improved maintenance of bone height compared with control sites. The Ti foam in a rod design exhibited bone ingrowth properties suitable for further exploration in other experimental situations.

SmvA, and not AcrB, is the major efflux pump for acriflavine and related compounds in Salmonella enterica serovar Typhimurium.

OBJECTIVES: The aim was to study the role played by SmvA pump in the efflux of quaternary ammonium compounds (QACs) in Salmonella enterica serovar Typhimurium (Salmonella Typhimurium). METHODS: Mutants in the smvA, acrB and tolC genes were constructed by the red swap method. P22 was used to transduce tolC to acrB and smvA mutant strains. The susceptibility of these strains to acriflavine and a variety of QACs was determined by MIC assays. RESULTS: In comparison with the Salmonella Typhimurium wild-type strain, the smvA mutant was more susceptible to QACs than the acrB mutant strain. A tolC single mutant was more susceptible than an acrB mutant to QACs, acriflavine, ethidium bromide, malachite green and pyronin B. The tolC-acrB double mutant was as susceptible as the single tolC mutant to QACs. Additionally, the smvA mutant strain was more susceptible to acriflavine than the acrB mutant (MICs = 31.3 versus 125 mg/L, i.e. 4-fold). Finally, the tolC-smvA double mutant (3.9 mg/L) was approximately 10 times more susceptible to acriflavine than either smvA (31.3 mg/L) or tolC (31.3 mg/L) single mutants. CONCLUSIONS: It is the SmvA efflux pump, and not AcrB, that plays the major role in the efflux of acriflavine and other QACs from Salmonella Typhimurium. This apparently conflicting report is due to the fact that in Escherichia coli the smvA gene does not exist. Our results suggest that tolC and smvA genes encode components of two different efflux systems with overlapping specificities that work in parallel to export acriflavine and other QACs.