Plasma concentrations of lidocaine in dogs following lidocaine patch application over an incision compared to intact skin

The objective was to compare plasma lidocaine concentrations when a commercially available 5% lidocaine patch was placed on intact skin vs. an incision. Our hypothesis was that greater absorption of lidocaine would occur from the incision site compared to intact skin. Ten dogs were used in a crossover design. A patch was placed over an incision, and then after a washout period, a patch was placed over intact skin. Plasma lidocaine concentrations were measured at patch placement; 20, 40 and 60 min; and 2, 4, 6, 12, 24, 36, 48, 72 and 96 h after patch placement. After patch removal, the skin was graded using a subjective skin reaction system. No dogs required rescue analgesia, and no toxicity or skin reaction was noted. Mean ± SD AUC and C_MAX were 3054.29 ± 1095.93 ng·h/mL and 54.1 ± 15.84 ng/mL in the Incision Group, and 2269.9 ± 1037.08 ng·h/mL and 44.5 ± 16.34 ng/mL in the No‐Incision Group, respectively. The AUC was significantly higher in the Incision Group. The results of the study demonstrate that the actual body exposure to lidocaine was significantly higher when an incision was present compared to intact skin. No adverse effects were observed from either treatment. Efficacy was not evaluated.     

Surgical stress and postoperative complications related to regional and radical mastectomy in dogs

Background

Surgery is the treatment of choice for regional control of mammary neoplasms in female dogs. Various surgical techniques may be used, as long as mammary gland anatomy, lymphatic drainage, and known prognostic factors are respected. The purpose of this study was to compare surgical stress—including duration of surgery, nociception and hematological changes—and postoperative complications in dogs undergoing regional and unilateral radical mastectomy. Eighteen dogs were selected for each technique. Postoperative pain (nociception), hematological changes, and postoperative complications were compared between the two groups.

Results

The group treated with radical mastectomy had a longer surgical duration, showed more intense physiological changes, achieved higher scores on nociception scales, and experienced more postoperative complications.

Conclusion

Compared to regional mastectomy, radical mastectomy was associated with longer surgical duration, greater nociceptive stimulus, greater surgical stress, and higher incidence of postoperative complications in dogs. Although evaluation of long-term results was not a goal of this study, it is suggested that postoperative recovery and patient quality of life should be considered when choosing a surgical approach for treating mammary tumors in dogs.     

Morphological and Morphometric Description of Female Reproductive Tract of Sapajus apella (Capuchin monkey)

Forest destruction has progressively hampered the survival of many species, and this is why it is so important to study of the lives of primates in captivity. This study aimed to describe the morphological aspects of the female reproductive tract of Sapajus apella. We used five animals obtained from the National Primate Center, Ananindeua – PA. The ovaries were paired, compact and symmetrical and had a smooth surface. The uterine tubes were bilateral and convoluted in adult animals and straight in young individuals. The uterus was simple and located in the pelvic region. The vagina was a long structure due to the position of the uterus. The external genitalia were located in the urogenital perineum and consisted of dark pigmented labia majora and labia minora, a vaginal vestibule as long as the vagina and a well‐developed clitoris. The results showed that the genitals of S. apella resemble those of other Neotropical primates.     

Cardiovascular tolerance of intravenous lidocaine in broiler chickens (Gallus gallus domesticus) anesthetized with isoflurane

ObjectiveTo determine the cardiovascular effects of lidocaine infused intravenously (IV) in broiler chickens.Study designTwo phase study: Phase 1, randomized up-and-down study to determine effective dose 50 (ED₅₀) for lidocaine; Phase 2, prospective randomized study to determine the cardiovascular effects of lidocaine.AnimalsSeventeen Ross-708 broiler chickens (Gallus gallus domesticus) [11 chickens (Phase 1) and 6 chickens (Phase 2)], weighing 2.6–4.3 kg.MethodsAfter induction of anesthesia with isoflurane and placement of monitoring equipment including invasive blood pressure, chickens were administered lidocaine IV. During Phase 1, using an up-and-down design, each animal received a variable dose selected based on the response of the previous animal. During Phase 2, each animal was administered 6 mg kg⁻¹ of lidocaine IV over 2 minutes. Clinically irrelevant cardiovascular effects were defined as a relative decrease of heart rate (HR) and mean blood pressure (MAP) <30% subsequent to IV lidocaine administration. The ED₅₀ was defined as the dose rate that would cause clinically irrelevant cardiovascular depression in 50% of the population.ResultsDuring Phase 1, using an up-and-down study design (n = 11), the ED₅₀ of lidocaine was determined to be 6.30 mg kg⁻¹ and 6.22 mg kg⁻¹ (95% confidence interval, 5.30–7.13 mg kg⁻¹), when calculated by Dixon's up-and-down method, and logistic regression, respectively. During Phase 2, following infusion of lidocaine (6 mg kg⁻¹), no clinically relevant effects on HR or MAP were detected in any animal.Conclusions and clinical relevancePrevious reports state that the dose of lidocaine used in birds should be =4 mg kg⁻¹. In this study, 6 mg kg⁻¹ of lidocaine injected IV was not associated with adverse cardiovascular effects. These results suggest that the dose of 4 mg kg⁻¹ can be exceeded, at least in chickens, and opens the possibility of other therapeutic uses for lidocaine in birds.     

Process-based modelling of erosion,sediment transport and reservoir siltation in mesoscale semi-arid catchments

Purpose

To support scientifically sound water management in dryland environments a modelling system has been developed for the quantitative assessment of water and sediment fluxes in catchments, transport in the river system, and retention in reservoirs. The spatial scale of interest is the mesoscale because this is the scale most relevant for management of water and land resources.

Materials and methods

This modelling system comprises process-oriented hydrological components tailored for dryland characteristics coupled with components comprising hillslope erosion, sediment transport and reservoir deposition processes. The spatial discretization is hierarchically designed according to a multi-scale concept to account for particular relevant process scales. The non-linear and partly intermittent run-off generation and sediment dynamics are dealt with by accounting for connectivity phenomena at the intersections of landscape compartments. The modelling system has been developed by means of data from nested research catchments in NE-Spain and in NE-Brazil.

Results and discussion

In the semi-arid NE of Brazil sediment retention along the topography is the main process for sediment retention at all scales, i.e. the sediment delivery is transport limited. This kind of deposition retains roughly 50 to 60 % of eroded sediment, maintaining a similar deposition proportion in all spatial scales investigated. On the other hand, the sediment retained in reservoirs is clearly related to the scale, increasing with catchment area. With increasing area, there are more reservoirs, increasing the possibility of deposition. Furthermore, the area increase also promotes an increase in flow volume, favouring the construction of larger reservoirs, which generally overflow less frequently and retain higher sediment fractions. The second example comprises a highly dynamic Mediterranean catchment in NE-Spain with nested sub-catchments and reveals the full dynamics of hydrological, erosion and deposition features. The run-off modelling performed well with only some overestimation during low-flow periods due to the neglect of water losses along the river. The simulated peaks in sediment flux are reproduced well, while low-flow sediment transport is less well captured, due to the disregard of sediment remobilization in the riverbed during low flow.

Conclusions

This combined observation and modelling study deepened the understanding of hydro-sedimentological systems characterized by flashy run-off generation and by erosion and sediment transport pulses through the different landscape compartments. The connectivity between the different landscape compartments plays a very relevant role, regarding both the total mass of water and sediment transport and the transport time through the catchment.     

Effects of Low Doses of Glufosinate-Ammonium on Upland Rice Agronomic Traits

The use of herbicides and growth regulators in agricultural crops to reduce vegetative growth is widely studied worldwide. This study aimed to evaluate the agronomic traits of upland rice subjected to low doses of glufosinate-ammonium applied at different development stages. The treatments consisted of five low doses (0; 15; 30; 60; and 100?g a.i. ha^?1; a.i.: active ingredient) of glufosinate-ammonium herbicide: a single low dose between active tillering (AT) and floral differentiation (FD); a single low dose after FD; low dose divided into two applications, the first at the beginning of the AT and the second between AT and FD; low dose divided into three applications, the first at the beginning of the AT, the second between AT and FD and the third after the FD, with four replications. The agronomic traits of upland rice were negatively affected due to the application of low doses of glufosinate-ammonium, with reduction in grain yield, 1000-grain weight, number of panicles, full spikelets and spikelets per panicle. Glufosinate-ammonium has no potential to be used as hormesis effect in rice plants due to loss in grain yield.

     

Interaction of common beans cultivars of the black group with years, locations and sowing seasons

The objectives of this study were to assess which environmental factors (local, season or years) are the most important to contribute for the interactions with genotypes of common black beans and to verify the existence of genotypes with broad and/or specific adaptation to the diverse planting seasons in Central Brazil. Data of grain yields for 13 genotypes in 18 field trials used for cultivar registration were utilized, across 2?years (2003 and 2004). Analyses of variance were carried out with decomposition of the genotype x environment interactions. Firstly, data of 18 trials were used, allowing a partial isolation of factors and, subsequently, eight trials were used to allow a complete isolation of the factors. The genotype x sowing seasons (R²?=?4.2?%) and genotype x year (R²?=?4.1?%) interactions were of the greatest important, while genotype x location was less important (R²?=?3.0?%). It was concluded that is more important to conduct evaluations of genotypes in different seasons and years rather than in different locations. The majority of the genotypes tested presented specific adaptation, although it was possible to identify superior lines with wide adaptation.     

Marjolin’s Ulcer in Two Horses with Hereditary Equine Regional Dermal Asthenia

Two Quarter Horse mares with hereditary equine regional dermal asthenia (HERDA) were diagnosed with metastatic squamous cell carcinoma (SCC) associated with chronic nonhealing wounds. The lesions were similar to the development of SCC from chronic nonhealing ulcers, known as Marjolin’s ulcers in humans. The horses showed recurrent skin wounds in the saddle and paralumbar regions and were confirmed by molecular techniques as having HERDA. Both horses were maintained as research animals for prolonged periods and received regular veterinary care and wound treatment. Both horses were ultimately euthanized because of their chronic progressive wounds, coupled with declining health. At necropsy, the nonhealing wounds were found to be complicated by infiltrative SCC; both horses had metastasis to lungs. Chronically inflamed, recurrent skin wounds that heal slowly and incompletely as a consequence of HERDA are proposed as a major pathogenetic factor in tumorigenesis. Consistent findings with respect to proliferation index (Ki-67) and mutations of p53 tumor suppressor gene were confirmed by immunohistochemistry in one horse. SCC consistent with Marjolin’s ulcer has been previously suggested in association with chronic ulcers or burn scars in horses, but this is the first report of an association with chronic poor healing wounds in HERDA horses.