Ultrasonographic assessment of regional radial and longitudinal systolic function in healthy awake dogs

BACKGROUND: Strain (St) and strain rate (SR) imaging are new ultrasound modalities based on tissue Doppler imaging (TDI) that allow quantitative assessment of segmental myocardial contraction or stretching and rate of deformation, respectively. HYPOTHESIS: Regional peak systolic St and SR could allow repeatable and reproducible assessment of systolic function of the right (RVW) and left (LVFW) myocardial walls in dogs. ANIMALS: Six healthy Beagle dogs were used to determine the repeatability and reproducibility of regional peak systolic St and SR in the RVW and LVFW (Study 1). These variables were also assessed in 30 healthy dogs of several breeds (Study 2). METHODS: Longitudinal peak systolic St and SR were recorded in 2 segments (basal and apical) of the RVW and LVFW. Radial peak systolic St and SR of the LVFW were also assessed. RESULTS: All within- and most (7/10) between-day coefficients of variation were <15%. Absolute values of the longitudinal deformation indices were significantly higher (P < .001) in the RVW (St = -39.5 +/- 5.5% and SR = -5.2 +/- 0.8 s(-1) at the base; St = -36.3 +/- 4.3% and SR = -4.7 +/- 1.1 s(-1) at the apex) than in the LVFW. Absolute values were also higher for the radial (St = 62.9 +/- 10.4% and SR = 5.8 +/- 1.1 s(-1), P < .001) than for the longitudinal LFVW motions. CONCLUSIONS AND CLINICAL IMPORTANCE: St and SR imaging is a repeatable and reproducible method for assessing systolic myocardial function. The combination of these indices with conventional echocardiographic variables may be useful for screening canine myocardial diseases.     

X-ray Structure of a self-compartmentalizing sulfur cycle metalloenzyme

Numerous microorganisms oxidize sulfur for energy conservation and contribute to the global biogeochemical sulfur cycle. We have determined the 1.7 angstrom-resolution structure of the sulfur oxygenase reductase from the thermoacidophilic archaeon Acidianus ambivalens, which catalyzes an oxygen-dependent disproportionation of elemental sulfur. Twenty-four monomers form a large hollow sphere enclosing a positively charged nanocompartment. Apolar channels provide access for linear sulfur species. A cysteine persulfide and a low-potential mononuclear non-heme iron site ligated by a 2-His-1-carboxylate facial triad in a pocket of each subunit constitute the active sites, accessible from the inside of the sphere. The iron is likely the site of both sulfur oxidation and sulfur reduction.     

Small strongyle infection: consequences of larvicidal treatment of horses with fenbendazole and moxidectin

The study was undertaken to evaluate adverse effects of larvicidal treatment in horses naturally infected with cyathostomins. Out of 24 ponies kept on pasture, four animals were housed in September and anthelmintically cured to serve as worm-free controls (group C-0). The others were housed in December. Eight animals each were treated 8 weeks later with 5 x 7.5mg/kg fenbendazole (FBZ) or 1 x 0.4 mg/kg moxidectin (MOX). Four animals remained untreated (group C-i). Two, 4, 6 and 14 days after the end of treatment two animals of each of the treated groups were necropsied together with group C-0 and C-i animals. Infected animals before treatment showed weight loss, eosinophilia, increased plasma protein and globulin contents. Treatment was followed by weight gain and temporal plasma protein and globulin increase. Proportions of CD4+ and CD8+ T lymphocytes in the peripheral blood did not differ between the groups before treatment but dropped significantly temporally after FBZ treatment. Group C-0 was worm-free at necropsy. Group C-i animals contained variable numbers of luminal and tissue cyathostomins. Histological sections showed larval stages in the lamina propria und submucosa surrounded by macrophages. Either treatment was effective against luminal parasites and reduced the number of larvae in the bowel wall beginning 4-6 days after FBZ and 6-14 days after MOX treatment. Histologically, as a first reaction after FBZ application T lymphocytes accumulated around morphologically intact L4 in the submucosa. Subsequently T lymphocytes associated with eosinophils infiltrated the submucosa. Parasites became enclosed by granulomas with eosinophils adhering to and invading the larvae which started to disintegrate on day 4. Later on, particularly on day 14 inflammation extended into the mucosa and was frequently associated with ulcerations. Third stage larvae in general and L4 in the lamina propria, however, seemed not to be affected until day 14 and even then, parasites did usually not generate extensive inflammation. After MOX treatment severe morphologically detectable alterations of tissue larvae could not be observed earlier than day 14. Different from FBZ treatment, larvae disintegrated and were obviously resorbed without causing severe inflammation in the gut wall. In conclusion treatment with either drug was efficacious against tissue larvae of cyathostomins but there may be different clinical consequences: in contrast to MOX effects, killing of larvae due to FBZ was associated with severe tissue damage, which clinically may correspond to reactions caused by synchronous mass emergence of fourth stage larvae, i.e., may mimic larval cyathostominosis.     

Caveolin-1 is essential for liver regeneration

Liver regeneration is an orchestrated cellular response that coordinates cell activation, lipid metabolism, and cell division. We found that caveolin-1 gene-disrupted mice (cav1-/- mice) exhibited impaired liver regeneration and low survival after a partial hepatectomy. Hepatocytes showed dramatically reduced lipid droplet accumulation and did not advance through the cell division cycle. Treatment of cav1-/- mice with glucose (which is a predominant energy substrate when compared to lipids) drastically increased survival and reestablished progression of the cell cycle. Thus, caveolin-1 plays a crucial role in the mechanisms that coordinate lipid metabolism with the proliferative response occurring in the liver after cellular injury.     

Supercritical CO2 extraction and purification of compounds with antioxidant activity

Supercritical fluid extraction (SCFE), based on the utilization of a fluid under supercritical conditions, is a technology suitable for extraction and purification of a variety of compounds, particularly those that have low volatility and/or are susceptible to thermal degradation. The interest in SCFE is promoted by legal limitations of conventional solvents for food and pharmaceutical uses. The physicochemical properties of supercritical CO2 (higher diffusivity, lower viscosity, and lower surface tension than conventional solvents) facilitate mass transfer and allow an environmentally friendly operation. This article presents a comprehensive compilation of data on the supercritical CO2 extraction of antioxidant compounds from vegetal materials, with particular attention to those of a phenolic nature. Aspects concerning the supercritical operation for extraction and fractionation of antioxidants compounds are considered, including equilibrium solubility of pure compounds and effects of the operational conditions on the antioxidant activity of isolated fractions. The data are compared to those reported for synthetic antioxidants and natural extracts obtained by conventional solvent extraction from vegetal matrices.     

Evaluation of the effects of animal age, concurrent bacterial infection, and pathogenicity of porcine reproductive and respiratory syndrome virus on virus concentration in pigs

OBJECTIVE: To evaluate the influences of animal age, bacterial coinfection, and porcine reproductive and respiratory syndrome virus (PRRSV) isolate pathogenicity on virus concentration in pigs. ANIMALS: Twenty-one 2-month-old pigs and eighteen 6-month-old pigs. PROCEDURE: Pigs were grouped according to age and infected with mildly virulent or virulent isolates of PRRSV. The role of concurrent bacterial infection was assessed by infecting selected pigs with Mycoplasma hyopneumoniae 21 days prior to inoculation with PRRSV. On alternating days, blood and swab specimens of nasal secretions and oropharyngeal secretions were collected. On day 21 after inoculation with PRRSV, selected tissues were harvested. Concentrations of PRRSV were determined by use of quantitative real-time PCR and expressed in units of TCID(50) per milliliter (sera and swab specimens) or TCID(50) per gram (tissue specimens). RESULTS: Concentrations of virus were higher in blood and tonsils of pigs infected with virulent PRRSV. Pigs infected with virulent PRRSV and M hyopneumoniae had significantly higher concentrations of viral RNA in lymphoid and tonsillar tissue. Coinfection with M hyopneumoniae resulted in a higher viral load in oropharyngeal swab specimens and blood samples, independent of virulence of the PRRSV isolate. Two-month-old pigs had significantly higher viral loads in lymph nodes, lungs, and tracheal swab specimens than did 6-month-old pigs, independent of virulence of the PRRSV isolate. CONCLUSIONS AND CLINICAL RELEVANCE: Multiple factors affect PRRSV concentration in pigs, including pathogenicity of the PRRSV isolate, age, and concurrent infection with M hyopneumoniae.     

Effect of administration of a controlled-release monensin capsule on incidence of calving-related disorders, fertility, and milk yield in dairy cows

OBJECTIVE: To determine the effect of a controlled-release monensin capsule administered at cessation of lactation on incidence of calving-related disorders, fertility, and milk yield in dairy cows. ANIMALS: 290 dairy cows treated with monensin and 290 untreated control cows. PROCEDURE: Treated cows received a capsule that released monensin at 335 mg/d for 95 days. Incidence of calving-related disorders; daily milk yield up to 20 days postpartum; test-day milk yield, fat, protein, and mature-equivalent 305-day milk production; and body condition score at calving were determined. Reproductive variables were conception rate at first service, pregnancy rate, and calving-to-conception interval. RESULTS: Cows treated with monensin were 2.1 times as likely to develop dystocia and 0.8 times as likely to develop metritis as control cows. For milk yield, there was an interaction of treatment X time X parity. In multiparous cows, monensin significantly improved milk yield at test days 4 and 7. In addition, monensin increased body condition score at calving. CONCLUSIONS AND CLINICAL RELEVANCE: Despite increasing the likelihood of developing dystocia and metritis, administration of monensin improved the lactational performance of multiparous cows and may be a promising additive for use at the time of cessation of lactation.     

Quantitative assessment of velocities of the annulus of the left atrioventricular valve and left ventricular free wall in healthy cats by use of two-dimensional color tissue Doppler imaging

OBJECTIVE: To analyze velocities of the annulus of the left atrioventricular valve and left ventricular free wall (LVFW) in a large population of healthy cats by use of 2-dimensional color tissue Doppler imaging (TDI). ANIMALS: 100 healthy cats (0.3 to 12.0 years old; weighing 1.0 to 8.0 kg) of 6 breeds. PROCEDURE: Radial myocardial velocities were recorded in an endocardial and epicardial segment, and longitudinal velocities were recorded in 2 LVFW segments (basal and apical) and in the annulus of the left atrioventricular valve. RESULTS: LVFW velocities were significantly higher in the endocardial than epicardial layers and significantly higher in the basal than apical segments. For systole, early diastole, and late diastole, mean +/- SD radial myocardial velocity gradient (MVG), which was defined as the difference between endocardial and epicardial velocities, was 2.2 +/- 0.7, 3.3 +/- 1.3, and 1.8 +/- 0.7 cm/s, respectively, and longitudinal MVG, which was defined as the difference between basal and apical velocities, was 2.7 +/- 0.8, 3.1 +/- 1.4, and 2.1 +/- 0.9 cm/s, respectively. A breed effect was documented for several TDI variables; therefore, reference intervals for the TDI variables were determined for the 2 predominant breeds represented (Maine Coon and domestic shorthair cats). CONCLUSIONS AND CLINICAL RELEVANCE: LVFW velocities in healthy cats decrease from the endocardium to the epicardium and from the base to apex, thus defining radial and longitudinal MVG. These indices could complement conventional analysis of left ventricular function and contribute to the early accurate detection of cardiomyopathy in cats.     

U1 and U2 small nuclear RNA genetic linkage: a novel molecular tool for identification of six sole species (Soleidae, Pleuronectiformes)

We evaluated the usefulness of a genetic linkage between the U1 and U2 small nuclear RNAs for species identification. Six soles belonging to the genera Solea, Dicologlossa, and Microchirus were studied. A simple methodology based on two single PCRs is described. Reproducible band profiles were generated for all samples. This rapid and discriminatory molecular method is highly promising for determining the authenticity of sole fillets in the food industry.     

Heat and pH effects on the conjugated forms of genistin and daidzin isoflavones

Isoflavones occur primarily as glycosides (namely, malonyl-, acetyl-, and non-conjugated beta-glycosides) and a small percentage as the bioactive aglycon. The different chemical structures of isoflavones can dictate their stability during processing. Therefore, our objective was to determine the effects of pH and thermal treatments on conjugated isoflavones with regard to interconversions and loss. Conjugated daidzin and genistin were heated at 25, 80, and 100 degrees C under neutral, acidic, and basic conditions. Changes in isoflavone derivatives were monitored using high-performance liquid chromatography. Along with interconversions, considerable loss in total known isoflavone derivatives was noted for each isoflavone, especially under elevated pH and temperature. The malonylglycosides showed more stability than acetylglycosides, especially under acidic conditions. Overall, loss in isoflavone derivatives was significantly higher for daidzin than for genistin glycoside forms. Our results highlighted the significance of chemical structure with regard to stability, which is a key factor in determining soy processing conditions.