A fatal pneumonia due to coinfection of Pseudomonas putida and Staphylococcus pseudintermedius in a laboratory beagle dog

Background: Pseudomonas putida (P. putida) is widely distributed in the environment, and sometimes caused nosocomialinfections in human beings, but no case of infection has been reported in beagle dogs. Staphylococcus pseudintermedius(S. pseudintermedius) is a natural cutaneous bacterium in dogs and occasionally causes purulent infections of the skin yetrarely causes pneumonia. Both bacteria are opportunistic pathogens. Dogs, even well-controlled laboratory beagle dogs,maybe infected by the bacterium in certain conditions like this report. In order to provide information and give suggestionto veterinarians involved in dogs study, a complete profile of the coinfection was drawn in this report.Case: It is presented a case of an 8-month-old beagle dog, weighing 6 kg that suffered from coinfection of P. putida andS. pseudintermedius during a treatment of chemotherapy. The animal was confirmed as normal by appearance, physicalexamination and laboratory tests before arrival according to the applicable guidelines. After 14-day acclimation period, theanimal was administrated with a tyrosinase inhibitor once daily via oral gavage. From Day 8, coughing, decreased activity, hyporeflexia, squinting, shortness of breath (abdominal breathing), and discharge around the nose as well as cracklesin the lung and rapid heart rate were noted. Since the poor conditions progressed quickly and have not been improved bytreatment of ceftriaxone and dexamethasone. On Day 9, the animal was euthanized for humanitarian reasons. To define thepathogen, hilar lymph node and thoracic swab were collected for bacteria isolation and purification in special mediums,and at last characterized by Gram staining and 16s rRNA gene sequence analysis and positive PCR-restriction fragmentlength polymorphism. In clinical pathological examination, an increase in WBC, neutrophils, lymphocytes, monocytes...

A fatal pneumonia due to coinfection of Pseudomonas putida and Staphylococcus pseudintermedius in a laboratory beagle dog

Background: Pseudomonas putida (P. putida) is widely distributed in the environment, and sometimes caused nosocomialinfections in human beings, but no case of infection has been reported in beagle dogs. Staphylococcus pseudintermedius(S. pseudintermedius) is a natural cutaneous bacterium in dogs and occasionally causes purulent infections of the skin yetrarely causes pneumonia. Both bacteria are opportunistic pathogens. Dogs, even well-controlled laboratory beagle dogs,maybe infected by the bacterium in certain conditions like this report. In order to provide information and give suggestionto veterinarians involved in dogs study, a complete profile of the coinfection was drawn in this report.Case: It is presented a case of an 8-month-old beagle dog, weighing 6 kg that suffered from coinfection of P. putida andS. pseudintermedius during a treatment of chemotherapy. The animal was confirmed as normal by appearance, physicalexamination and laboratory tests before arrival according to the applicable guidelines. After 14-day acclimation period, theanimal was administrated with a tyrosinase inhibitor once daily via oral gavage. From Day 8, coughing, decreased activity, hyporeflexia, squinting, shortness of breath (abdominal breathing), and discharge around the nose as well as cracklesin the lung and rapid heart rate were noted. Since the poor conditions progressed quickly and have not been improved bytreatment of ceftriaxone and dexamethasone. On Day 9, the animal was euthanized for humanitarian reasons. To define thepathogen, hilar lymph node and thoracic swab were collected for bacteria isolation and purification in special mediums,and at last characterized by Gram staining and 16s rRNA gene sequence analysis and positive PCR-restriction fragmentlength polymorphism. In clinical pathological examination, an increase in WBC, neutrophils, lymphocytes, monocytes...(AU)

Expression dynamics of caveolin-1 in fibroblasts of newborn rats with chronic lung disease and its impact on lung fibroblast proliferation

Purpose: To evaluate the changes of caveolin-1 in lung fibroblasts in newborn Wistar rats when exposed to hyperoxic conditions, as well as lung fibroblasts cell cycle. Methods: One hundred newborn Wistar rats were randomly divided (50 rats/group) into experimental and control groups, exposed to hyperoxic conditions or normal air, respectively. The fraction of inspired oxygen (FiO2) in the experimental group was 90%, whereas this value was 21% in the control group. Lung fibroblasts were collected on days 3, 7, and 14 of the experiment. Caveolin-1 expression dynamics in lung fibroblasts was assayed in each group by immunofluorescence and Western blot analyses. Flow cytometry (FCM) was used to assess the proportions of lung fibroblasts at different stages of the cell cycle. Results: On day 3, no significant difference in caveolin-1 expression was observed between the hyperoxic and control groups; however, on days 7 and 14, caveolin-1 expression was significantly lower in the hyperoxic group than in the control (P 0.05). No apparent differences were observed in caveolin-1 expression in the control group at the different time points. Using FCM analysis, we showed that the proportion of lung fibroblasts in G0/G1 phase in the hyperoxic group decreased compared to that of the control group on day 7, while the proportion of S-phase cells increased (P 0.05). These differences were more significant when the groups were compared on day 14 (P 0.01). Conclusion: After seven days the exposure to hyperoxic conditions, lung fibroblasts proliferated and caveolin-1 expression decreased.(AU)

Dexmedetomidine preconditioning inhibits the long term inflammation induced by renal ischemia/reperfusion injury in rats

PURPOSE:To investigate the protective effects of dexmedetomidine (Dex) against renal ischemia/reperfusion injury (IRI).METHODS:Sprague-Dawley rats were randomly divided to sham group, IRI group and Dex group. The SD rats were subjected to 45 min of ischemia followed by eight weeks of reperfusion. Prior to ischemia, rats were either treated with Dex or not. Blood samples were collected for the detection of blood urea nitrogen (BUN) and creatinine (Cr) levels. Immunohistochemistry was performed for CD3 T-cell infiltrates. Real-time PCR and western blot were detected for the expression of TNF-α, IL-1β, ICAM-1, HMGB1 and TLR4.RESULTS:Compared with sham group, renal IRI significantly increased the serum levels of BUN and Cr. The H&E staining indicated that renal IRI resulted in obvious renal injury and immunohistochemistry found that there were more CD3 T-cell infiltrates in IRI group. Also, renal IRI upregulated the expression of TNF-α, IL-1β, ICAM-1, HMGB1 and TLR4. However, all these changes were alleviated by the treatment with Dex.CONCLUSIONS:Dexmedetomidine has beneficial effects on long term inflammation induced by renal ischemia/reperfusion injury. Its mechanisms may be achieved through inhibiting the HMGB1/TLR4 pathway to exert protective effects.(AU)