Alveolar recruiting maneuver in dogs under general anesthesia: effects on alveolar ventilation,gas exchange,and respiratory mechanics

The aim of this study was to evaluate the effects of a recruiting maneuver (RM) on lung aeration, gas exchange, and respiratory mechanics during general anesthesia in mechanically ventilated dogs. A thoracic computed tomography (CT) scan, an arterial blood sample, and measurement of respiratory mechanics were performed 10 min before (baseline) and both 5 and 30 min after a vital capacity RM in 10 dogs under general anesthesia. The RM was performed by inflating the lung at 40 cm H₂O for 20 s. Lung aeration was estimated by analyzing the radiographic attenuation of the CT images. Lung aeration and gas exchange improved significantly 5 min after the RM compared to baseline and returned to values similar to baseline by 30 min. Static lung compliance was not significantly affected by the RM. An RM induces a temporary improvement in lung function in healthy dogs under general anesthesia.

     

Detection of early embryonic development in chicken eggs using visible light transmission

1. In two separate experiments, the possibility of detecting embryonic development in chicken eggs was assessed using the same spectrophotometric method used to detect blood in Table eggs, using a combination of two wavelengths (577 and 610 nm) of the transmission spectrum. 2. In the first experiment, during the first 10 d of incubation, transmission spectra of 30 Hisex White eggs and 30 Hybro eggs were measured daily. 3. In the second experiment, 292 Hisex White eggs were incubated. Seven groups were randomly assigned. Six received an injection of sodium azide (NaN3) at different times during incubation in order to stop embryonic development, and during the first 12 d of incubation the transmission spectrum was measured daily. The acoustic resonance analysis method was also used on a group of uninjected eggs. 4. In the first experiment, it was possible to detect embryonic development from 120 h of incubation onwards in fertile eggs. In the second experiment changes in light transmission due to embryonic development were detected from 108 h of incubation. Detection of embryonic development using the acoustic resonance analysis method in the second experiment was possible only from 120 h of incubation. 5. It was concluded that the detection of embryonic development using visible light transmission is not directly linked with the formation of blood, but with the formation of sub-embryonic fluid, which takes place from 72 h of incubation onwards. This fluid makes the yolk sac translucent so that absorption of light at 577 nm can be detected.     

Comparison of conservative management and juvenile pubic symphysiodesis in the early treatment of canine hip dysplasia.

OBJECTIVES: To evaluate the efficacy of juvenile pubic symphysiodesis (JPS) in a clinical setting for the early treatment of canine hip dysplasia (CHD), and to identify its indications and contraindications. METHODS: The final degree of CHD using the FCI (Fédération Cynologique Internationale) CHD classification in 5 Grades (A, B, C, D, E) was assessed at skeletal maturity in two homogeneous groups of dogs assessed at the age of 14 to 22 weeks and selected according to their susceptibility to CHD; one group was treated with JPS and one group was conservatively managed. Two hundred seventeen puppies completed the study; 81 were treated with JPS (group 1) and 76 were conservatively managed (group 2). A third group of 60 puppies with normal hips was followed as a negative control group. RESULTS: In group 1, 43.2% of the puppies had regression or a lack of progression of the disease in the final evaluation (Grade A & B), 25.9% had mild CHD (Grade C) and 30.9% had moderate and severe CHD (Grade D & E). In group 2, 23.6% of the puppies did not show any development of the disease (Grade A & B), 21.1% had mild CHD (Grade C) and 55.3% developed moderate to severe CHD (Grade D & E). Further investigation was done by comparing the severity of early signs of susceptibility to CHD with the final FCI Grades at adulthood in both groups. CLINICAL SIGNIFICANCE: The JPS procedure increased the odds of arresting or limiting the progression of CHD in mild to moderate grades of CHD, while it was less effective or ineffective in more severe forms.     

The Bovine Luteal Histological Composition: A Topographic Point of View

High‐yielding dairy cows are struggling with a high incidence of embryonic loss, among others caused by an insufficient peripheral progesterone concentration which for its part might be associated with an impaired luteal progesterone production. This impaired capacity to produce progesterone might be reflected in the histology of the gland. The aim of the present pilot study was the assessment of the variation in cell density within a bovine luteal gland (LG), to examine whether it is possible to analyse histologically the functionality of the gland based on one single tissue sample. Six LGs (stage II or III) were harvested out of just as many healthy cows at the slaughterhouse. The luteal cell density was assessed by calculating the nuclear density (ND) of the different luteal cell types on haematoxylin‐eosin‐stained histological sections from a number of topographic regions evenly spread throughout the glands, to give an overview of the pattern of cellular distribution within the whole gland. Cells were differentiated into ‘large luteal cells’, ‘small luteal cells’ and ‘non‐steroidogenic cells’. Results show that the cellular density, within a tissue sample is not significantly influenced by its location in relation to the gland's equatorial plane. However, the position with respect to the polar axis of the gland has a decisive effect, as the ND is significantly higher (p < 0.05) in the peripheral regions (outer zone) when compared with the central regions (inner zone) of the gland, and this counts for all three cell types.     

Adhesion of Escherichia coli K88ab fimbriae to porcine enterocytes: effect on enzymatic activities of the brush border, and cyclic AMP and GMP levels

We have studied the cellular alterations, after in vitro adherence, of purified K88ab fimbriae to membranes of porcine enterocytes. Effects on enzymatic activities as disaccharydases and alkaline phosphatase show low changes. While cAMP levels were decreased (44%), guanylyl cyclase was increased (up to 200%), and levels of cGMP were in consequence significantly affected. This study support the role of cyclic GMP as intracellular mediator for adherence, and suggest their implication in disease, affecting a membrane-mediated mechanisms for guanylate cyclase activation, that is unique in the intestine.     

A survey of mutations in the Cochliomyia hominivorax (Diptera: Calliphoridae) esterase E3 gene associated with organophosphate resistance and the molecular identification of mutant alleles

Cochliomyia hominivorax (Calliphoridae) is one of the most important myiasis-causing flies and is responsible for severe economic losses to the livestock industry throughout the Neotropical region. In Brazil, C. hominivorax has been controlled mainly with organophosphate (OP) insecticides, although the inappropriate use of these chemicals can result in the selection of resistant flies. Changes in carboxylesterase activity have been associated with OP insecticides in some arthopodan species. In this work, we isolated and characterized part of the E3 gene in C. hominivorax (ChE7), which contained the same substitutions responsible for the acquisition of OP hydrolase activity in Lucilia cuprina (Calliphoridae). Digestion of the polymerase chain reaction products with a restriction enzyme that specifically recognized the mutation site unambiguously differentiated wild and mutated esterase alleles. The PCR-RFLP assay therefore provided a fast, reliable DNA-based method for identifying C. hominivorax individuals with a mutation in the esterase gene. Further bioassays to determine the association of this mutation with OP resistance in C. hominivorax should allow the development of more effective strategies for managing this species.     

Serum α-globulin fraction in horses is related to changes in the acute phase proteins

Serum electrophoresis is a useful technique to diagnose some diseases characterized by quantitative and qualitative changes in the serum proteins, such as the acute phase proteins. An increased synthesis of acute phase proteins has been associated with acute infection and inflammation. We wanted to study whether gastrointestinal diseases and disorders of the locomotor system in horses produce enough inflammatory reaction so the acute phase proteins can be detected by electrophoresis in serum. Serum total proteins were calculated, and the serum electrophoresis from 63 horses was performed. The horses were classified in 3 groups: Group I (19 healthy horses), Group II (20 horses suffering from inflammatory disorders of the gastrointestinal tract), and Group III (24 horses with inflammatory disorders of the locomotor system). Results indicated an increase of the acute phase proteins only in patent inflammatory disorders that showed a rapid progression. A global increase in those proteins was observed only for α₁-globulins from Group II.     

Muscle reorganisation through local injection of stem cells in the diaphragm of mdx mice

Background

The diaphragm is the major respiratory muscle affected by Duchenne muscular dystrophy (DMD) and is responsible for causing 80% of deaths. The use of mechanical forces that act on the body or intermittent pressure on the airways improves the quality of life of patients but does not prevent the progression of respiratory failure. Thus, diseases that require tissue repair, such as DMD, represent a group of pathologies that have great potential for cell therapy. The application of stem cells directly into the diaphragm instead of systemic application can reduce cell migration to other affected areas and increase the chances of muscle reorganisation. The mdx mouse is a suitable animal model for this research because its diaphragmatic phenotype is similar to human DMD. Therefore, the aim of this study was to assess the potential cell implantation in the diaphragm muscle after the xenotransplantation of stem cells.

Methods

A total of 9 mice, including 3 control BALB/Cmice, 3 5-month-old mdx mice without stem cell injections and 3 mdx mice injected with stem cells, were used. The animals injected with stem cells underwent laparoscopy so that stem cells from GFP-labelled rabbit olfactory epithelium could be locally injected into the diaphragm muscle. After 8 days, all animals were euthanised, and the diaphragm muscle was dissected and subjected to histological and immunohistochemical analyses.

Results

Both the fresh diaphragm tissue and immunohistochemical analyses showed immunopositive GFP labelling of some of the cells and immunonegativity of myoblast bundles. In the histological analysis, we observed a reduction in the inflammatory infiltrate as well as the presence of a few peripheral nuclei and myoblast bundles.

Conclusion

We were able to implant stem cells into the diaphragm via local injection, which promoted moderate muscle reorganisation. The presence of myoblast bundles cannot be attributed to stem cell incorporation because there was no immunopositive labelling in this structure. It is believed that the formation of the bundles may have been stimulated by cellular signalling mechanisms that have not yet been elucidated.