Serum butyrylcholinesterase activity in healthy dogs with and without exposure to diazinon.

BACKGROUND: Cholinesterase is a biomarker for poisonings by anticholinesterase agents, but its reference values are scarce, and possible interaction with collars containing parasiticides has not been studied. OBJECTIVES: We aimed to evaluate the serum cholinesterase activity of healthy dogs without a history of contact with anticholinesterase agents and healthy animals exposed to commercial collars containing organophosphate. METHODS: Ninety-nine dogs were used and included healthy animals without recent exposure to anticholinesterase agents and healthy animals previously exposed to diazinon collars. Serum quantification of the enzyme butyrylcholinesterase (BuchE) through spectrophotometry was conducted on all samples. In experiment 1, BuchE activity was quantified at time 0 and 7 days after, a time when the samples were kept at -18°C. In experiment 2, sampling times were 0, 7, 14, 21, 28, and 56 days. RESULTS: Time 0 values were 4622.38 ± 1311.53 U/L. After 7 days, a significant decay was observed, with a mean of 3934.45 ± 1430.45 U/L. Spearman's test was performed, finding a weak correlation between ALT, creatinine, total plasma proteins, age, weight, red blood cells, platelets, leukocytes, and BuchE activities. In experiment 2, the mean at time 0 was 4753 ± 454.8 U/L. With exposure to the collar, there was a decay of up to 93% after 14 days. CONCLUSIONS: Normality values of serum BuchE in healthy dogs without a history of exposure to anticholinesterase agents were 4360.8-4883.96 U/L. Freezing serum caused a decrease in BuchE activity. Exposure to commercial collars containing diazinon also reduced BuchE activity without clinical signs, indicating that previously exposed animals should be evaluated carefully.

Influential Factors on the Evaluation of Adamkiewicz Artery Using a 320-Detector Row Computed Tomography Device.

BACKGROUND: Understanding the difference of Adamkiewicz artery (AKA) presentation in healthy and diseased subjects, and the influence of atherosclerotic factors prevalent in aortic disease patients, are important for aortic disease therapeutic planning. This study used a 320-detector row computed tomography (CT) device to examine the impact of clinical aspects of AKA identification in individuals with and without aortic disease. METHODS: Angio-CTs obtained from 115 patients were assessed and the individuals grouped according to the presence or absence of aortic disease. Datasets were analyzed using OsiriX software, and AKA was identified by three-dimensional multiplanar reconstruction. RESULTS: The group without aortic disease (Group A) comprised 32 (52.5%) men and 29 women, with a mean age of 53.7 ± 16.8 years. The group with aortic disease (Group B) comprised 31 (57.4%) men and 23 women, with a mean age of 64.8 ± 11.6 years. AKA was identified in 49 (80.3%) participants of Group A and 23 (42.6%) individuals of Group B (P ≤ 0.0001). In 53 cases (73.6%), AKA originated on the left side. AKA was mainly detected on the left side (73.6%), at the level of T10 to T12 (70%). Tobacco smokers, former smokers, and hypertensive patients had increased odds of having undetected AKA. CONCLUSIONS: Using the method described and a state of the art 320-detector row CT device, AKA was detected more frequently among individuals without aortic disease. Thus, aortic disease and atherosclerotic risk factors hindered AKA detection.

Effect of short-term regulated temperature variations on the swimming economy of Atlantic salmon smolts.

Migratory species travelling long distances between habitats to spawn or feed are well adapted to optimize their swimming economy. However, human activities, such as river regulation, represent potential threats to fish migration by changing environmental parameters that will have impact on their metabolism. The main objective of this study was to evaluate the changes in the swimming energetics of a salmonid species, Atlantic salmon (Salmo salar L.), caused by short-term temperature variations that usually result from the operation of hydroelectrical dams. Intermittent flow respirometry in swim tunnels allows to obtain high resolution data on oxygen consumption of swimming fish which can reflect aerobic and anaerobic metabolism. This method was used to compare the metabolic rates of oxygen consumption before, during and after sudden thermal change. Control (no temperature variation) and experimental (temperature variation of approximately 4°C in 1 h) swimming trials were conducted to achieve the following objectives: (i) quantify the variations in oxygen consumption associated with abrupt temperature decrease, and (ii) assess if the tested fish return quickly to initial oxygen consumption rates. Main results revealed that Atlantic salmon smolts show a strong response to sudden temperature variation, significantly reducing the oxygen consumption rate up to a seven-fold change. Fish quickly returned to initial swimming costs shortly after reestablishment of temperature values. Results from this study can be used to evaluate the species-specific effects of the applied operation modes by hydroelectrical dams and to increase the success of conservation and management actions directed to fish species inhabiting regulated rivers.

An unusual case of dysphagia after endovascular exclusion of thoracoabdominal aortic aneurysm.

PURPOSE: To report an unusual case of dysphagia that developed immediately after stent-grafting of a thoracoabdominal aortic aneurysm. CASE REPORT: A 79-year-old woman was submitted to a staged hybrid repair of a thoracoabdominal aortic aneurysm and developed new onset dysphagia and regurgitation early after stent-grafting of the thoracic aorta. Esophageal imaging showed a marked endoluminal stenosis, suggesting the development of secondary achalasia. The patient was submitted to endoscopic injections of botulinum toxin at the lower esophageal sphincter, which completely resolved the symptoms. CONCLUSION: Acute dysphagic syndrome after thoracic aorta endografting has been anecdotically reported, and its etiology remains undefined. In this report, we illustrate the clinical features of this rare condition, discuss etiological hypotheses, and suggest a noninvasive therapeutic approach.

An extrasolar planetary system with three Neptune-mass planets.

Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 au (the Sun-Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star.

Mercury's capture into the 3/2 spin-orbit resonance as a result of its chaotic dynamics.

Mercury is locked into a 3/2 spin-orbit resonance where it rotates three times on its axis for every two orbits around the sun. The stability of this equilibrium state is well established, but our understanding of how this state initially arose remains unsatisfactory. Unless one uses an unrealistic tidal model with constant torques (which cannot account for the observed damping of the libration of the planet) the computed probability of capture into 3/2 resonance is very low (about 7 per cent). This led to the proposal that core-mantle friction may have increased the capture probability, but such a process requires very specific values of the core viscosity. Here we show that the chaotic evolution of Mercury's orbit can drive its eccentricity beyond 0.325 during the planet's history, which very efficiently leads to its capture into the 3/2 resonance. In our numerical integrations of 1,000 orbits of Mercury over 4 Gyr, capture into the 3/2 spin-orbit resonant state was the most probable final outcome of the planet's evolution, occurring 55.4 per cent of the time.

Treatment of Paget's disease of bone with ethane-1, hydroxy-1,1 diphosphonate (EHDP) at a low dosage (5 mg/kg/day).

Paget's disease of bone in 51 patients was treated with ethane-1, hydroxy-1,1 diphosphonate (EHDP) for six months at a dosage of 5 mg/kg/day. Clinically, the analgesic effect on bone pain is clear, with parallel reduction in radioisotope uptake observed by quantitative bone scintigraphy. There is also a reduction of about 70% of the excess level of serum alkaline phosphatase and total 24-hour urinary hydroxyproline. Histologically, there is a significant reduction in both the osteoclastic resorption surfaces and the number of osteoclasts. In contrast to that obtained by calcitonin, these clinical, biologic, and histologic changes continue for at least one year beyond the end of the treatment. That is the main characteristic of this treatment, of which the clinical and biologic tolerance is admittedly very satisfactory. Accumulation of osteoid tissue, which is indicative of a mineralization defect, does not appear at low dosages under the prescribed conditions. EHDP (5 mg/kg/day) can be regarded as effective treatment for some patients with Paget's disease of bone.

Effects of disodium dichloromethylene diphosphonate on hypercalcemia produced by bone metastases.

The aim of this study was to determine the ability of disodium dichloromethylene diphosphonate (Cl2MDP) to reduce the hypercalcemia secondary to skeletal metastases and induced by stimulation of bone resorption by malignant cells. Five patients with hypercalcemia due to bone metastases of breast or renal cancer were treated orally for 4 wk with 3,200 mg of Cl2MDP and 4 wk with a placebo in a double blind, crossover study. During the Cl2MDP period of administration four patients experienced a rapid and significant decrease in serum calcium and urinary calcium excretion together with an increase in alkaline phosphatase. In the remaining patient who developed a sudden paraplegia at the onset of the therapy followed by a marked increase in serum calcium levels and urinary calcium excretion, Cl2MDP was able to reverse this worsening of hypercalcemia or to reduce serum and urinary calcium to normal values. For all patients, urinary hydroxyproline excretion was unchanged during the Cl2MDP period when compared with the prestudy or placebo periods. From these results, and because of the rapid relapse of hypercalcemia during the placebo period or after withdrawal of the treatment, we can conclude that Cl2MDP is capable of reducing excessive mobilization of calcium resulting from bone metastases.