Long term consequences of low birthweight on postnatal growth, adiposity and brain weight at maturity in sheep

Low birth weight (LBW) as a result of restricted fetal growth increases the risk for later metabolic diseases and adiposity. However the relationship between LBW and postnatal growth and adult body composition has not been fully investigated. We have used sheep to determine the effects of LBW on postnatal growth and body composition at maturity. LBW was induced by twinning and placental embolization. At birth, LBW lambs were 38% lighter than controls (2.8 +/- 0.2 vs 4.4 +/- 0.3 kg, P<0.05), but had caught up in bodyweight by 8 weeks after birth. At approximately 2.3 years, bodyweights were not different between groups, but there were reductions in absolute (-8%) and relative (-17%) brain weights of LBW sheep (P<0.05) compared to controls. X-ray absorptiometry showed that the mature LBW sheep, compared to controls, had greater amounts of lean muscle (38.1 +/- 1.3 vs 35.3 +/- 0.5 kg, P<0.05) and tended to have more body fat (12.2 +/- 1.2 vs 9.6 +/- 0.9 kg; P=0.1); at autopsy abdominal fat mass was greater in LBW sheep (3.06 +/- 0.26 vs 2.20 +/- 0.25 kg, P<0.05). Plasma leptin concentrations were not different between groups. We conclude that, in sheep, LBW is associated with early postnatal catch-up in body weight, but body composition is permanently altered such that, relative to controls, adiposity is increased and brain weight is decreased.     

Intramuscular anesthesia of bonito and Pacific mackerel with ketamine and medetomidine and reversal of anesthesia with atipamezole

OBJECTIVE: To determine anesthetic effects of ketamine and medetomidine in bonitos and mackerels and whether anesthesia could be reversed with atipamezole. DESIGN: Clinical trial. ANIMALS: 43 bonitos (Sarda chiliensis) and 47 Pacific mackerels (Scomber japonica). PROCEDURE: 28 bonitos were given doses of ketamine ranging from 1 to 8 mg/kg (0.5 to 3.6 mg/lb), i.m., and doses of medetomidine ranging from 0.2 to 1.6 mg/kg (0.1 to 0.7 mg/lb), i.m. (ratio of ketamine to medetomidine, 2.5:1 to 20:1). Doses of atipamezole equal to 1 or 5 times the dose of medetomidine were used. The remaining 15 bonitos were used to determine the anesthetic effects of ketamine at a dose of 4 mg/kg (1.8 mg/lb) and medetomidine at a dose of 0.4 mg/kg (0.2 mg/lb). The mackerels were given ketamine at doses ranging from 11 to 533 mg/kg (5 to 242 mg/lb) and medetomidine at doses ranging from 0.3 to 9.1 mg/kg (0.1 to 4.1 mg/lb; ratio of ketamine to medetomidine, 3:1 to 800:1). Doses of atipamezole equal to 5 times the dose of medetomidine were used. RESULTS: I.m. administration of ketamine at a dose of 4 mg/kg and medetomidine at a dose of 0.4 mg/kg in bonitos and ketamine at a dose of 53 to 228 mg/kg (24 to 104 mg/lb) and medetomidine at a dose of 0.6 to 4.2 mg/kg (0.3 to 1.9 mg/lb) in mackerels was safe and effective. For both species, administration of atipamezole at a dose 5 times the dose of medetomidine reversed the anesthetic effects. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a combination of ketamine and medetomidine can safely be used for anesthesia of bonitos and mackerels and that anesthetic effects can be reversed with atipamezole.     

Increased sacral screw purchase minimizes screw loosening in canine triple pelvic osteotomy

OBJECTIVE: To determine if screw loosening in triple pelvic osteotomies (TPO) is minimized when screws cranial to the ilial osteotomy had maximal sacral purchase. STUDY DESIGN: Prospective study. ANIMALS: Forty-six dogs with decreased acetabular coverage of the femoral head and minimal degenerative joint changes. METHODS: TPOs were performed where screws cranial to the ilial osteotomy were inserted to maximally engage sacral bone. Data collected were: use of ilial and ischial cerclage wire, screw length, ventrodorsal radiographic sacral width (most caudal aspect), pelvic canal diameter, and sacral penetration of the 3 cranial screws. On all subsequent radiographs, changes in screw position, pelvic canal diameter, and sacral purchase were noted. RESULTS: For 69 TPOs, 414 screws were used. Mean radiographic cranial screw length was 34.54 mm. Combined sacral depth of all 3 screws was 93.3% of sacral width. All osteotomies healed uneventfully. Twenty-four screws (6%) loosened with 12 being in the most cranial positions. Use of ischial or ilial cerclage wires did not statistically influence screw loosening. Pelvic diameter decreased by a mean of 7.79% from postoperative radiographs to the last radiographic recheck. CONCLUSIONS: By sufficiently engaging the sacrum with screws cranial to the ilial osteotomy, implant failures can be avoided and screw loosening minimized when a 6-hole TPO plate is used. CLINICAL RELEVANCE: To minimize screw-loosening in TPO, screws inserted cranial to the ilial osteotomy should be inserted to maximum sacral depth without penetrating the vertebral canal.     

Neurobiological substrates of dread

Given the choice of waiting for an adverse outcome or getting it over with quickly, many people choose the latter. Theoretical models of decision-making have assumed that this occurs because there is a cost to waiting-i.e., dread. Using functional magnetic resonance imaging, we measured the neural responses to waiting for a cutaneous electric shock. Some individuals dreaded the outcome so much that, when given a choice, they preferred to receive more voltage rather than wait. Even when no decision was required, these extreme dreaders were distinguishable from those who dreaded mildly by the rate of increase of neural activity in the posterior elements of the cortical pain matrix. This suggests that dread derives, in part, from the attention devoted to the expected physical response and not simply from fear or anxiety. Although these differences were observed during a passive waiting procedure, they correlated with individual behavior in a subsequent choice paradigm, providing evidence for a neurobiological link between the experienced disutility of dread and subsequent decisions about unpleasant outcomes.     

The Drought Calculator: Decision Support Tool for Predicting Forage Growth During Drought

The Drought Calculator (DC), a spreadsheet-based decision support tool, was developed to help ranchers and range managers predict reductions in forage production due to drought. Forage growth potential (FGP), the fraction of historical average production, is predicted as a weighted average of monthly precipitation from January through June. We calibrated and evaluated the DC tool in the Great Plains of the United States, using FGP and precipitation data from Colorado (CO), North Dakota (ND), and Wyoming (WY). In CO, FGP was most sensitive to precipitation in April and May, in ND to precipitation in April and June, and in WY to precipitation in April, May, and June. Weights in these months ranged from 0.16 to 0.52. Prediction was better for CO and WY than for ND. When January–June precipitation was used, the tool correctly predicted 83% of the years with FGP reduced by drought for CO, 82% for WY, and only 67% for ND. Positive values of the True Skill Statistic (0.53 for CO, 0.42 for WY, and 0.17 for ND) indicate that FGP was classified as above or below average better than random selection. Predicting FGP earlier than April in CO and WY will require accurate forecasts of April–June precipitation. Use of the DC is most limited by insufficient forage data to determine the site-specific relationships between FGP and monthly precipitation. Even so, the decision tool is useful for discriminating drought effects on FGP classification being above or below the long-term average, and it provides a quantitative prediction to producers for their destocking decisions in drought years.     

The immune modifying effects of amino acids on gut-associated lymphoid tissue

The intestine and the gut-associated lymphoid tissue（GALT） are essential components of whole body immune defense,protecting the body from foreign antigens and pathogens,while allowing tolerance to commensal bacteria and dietary antigens.The requirement for protein to support the immune system is well established.Less is known regarding the immune modifying properties of individual amino acids,particularly on the GALT.Both oral and parenteral feeding studies have established convincing evidence that not only the total protein intake,but the availability of specific dietary amino acids（in particular glutamine,glutamate,and arginine,and perhaps methionine,cysteine and threonine） are essential to optimizing the immune functions of the intestine and the proximal resident immune cells.These amino acids each have unique properties that include,maintaining the integrity,growth and function of the intestine,as well as normalizing inflammatory cytokine secretion and improving T-lymphocyte numbers,specific T cell functions,and the secretion of IgA by lamina propria cells.Our understanding of this area has come from studies that have supplemented single amino acids to a mixed protein diet and measuring the effect on specific immune parameters.Future studies should be designed using amino acid mixtures that target a number of specific functions of GALT in order to optimize immune function in domestic animals and humans during critical periods of development and various disease states.     

Landscape setting and risk of Ranavirus mortality events

Amphibian mortality events in relatively pristine and protected settings cause particular concern because they may be linked to larger scale, off-site factors that interact with local landscape features. We used logistic regression and model selection criterion (QAIC_c) to identify landscape features key to predicting disease incidence in Acadia National Park (ANP), Maine, USA. High catchment position was the most important landscape feature associated with larval mortality events in ANP wetlands, and was present in all competing models. No spatial autocorrelation of disease events was observed, suggesting that within our study area, epizootics are not clustered and landscape and within-pond stressors may be more influential in mortality occurrence than vector movement. However, our model may be a considerable underestimate of in-field infection rates because it was based on die-off event incidences and did not include infected reservoirs or vectors. This study provides the first clear connection between landscape position and Ranavirus mortality events. Conservation and disease containment efforts in ANP should be directed toward higher catchment position and headwater wetlands such as vernal pools.     

Experimental snowpack reduction alters organic matter and net N mineralization potential of soil macroaggregates in a northern hardwood forest

Climate change is predicted to reduce or delay annual wintertime snow pack formation in the forests of the northeastern US. Any delay in snowpack formation could increase soil freezing in winter and, thereby, alter soil characteristics and processes. We examined the hypothesis that delayed snowpack would disrupt soil structure and change organic matter bioavailability in an experimental snow removal study at the Hubbard Brook Experimental Forest (HBEF), NH, USA. Pairs of reference and snow removal treatment plots were studied in four different sites at HBEF. Snow was removed from November–January of two winters, inducing soil freezing throughout both winters. Size class distribution and organic matter concentration and content of aggregates, and carbon and nitrogen mineralization potential of size fractions were quantified for surface mineral soils in the spring of both years immediately after snowmelt. In the first year of sampling, the only significant effect of snow removal was an increase in the smallest (<53 μm) size fraction of mineral soil. In the second year, snow removal increased organic matter concentrations of macroaggregate (250–2,000 μm) and microaggregate (53–250 μm) size fractions. This change corresponded to an increase in net N mineralization potential and the ratio of N to C mineralized in the macroaggregate fraction, but there were no effects of snow removal on C mineralization. We propose that soil freezing increases the movement of organic matter from organic to mineral soil horizons and increases the N content of mineralizable substrates in mineral soil following years with delayed snowpack formation.     

Stress alters the cellular and proteomic compartments of bovine bronchoalveolar lavage fluid

The stresses of transportation, weaning and commingling are associated with an increased incidence of bacterial and viral pneumonia in cattle. Proteins expressed in the epithelial lining fluid (ELF) of the lungs, in conjunction with resident leukocytes, represent the first line of defence against opportunistic pathogens, and stress-induced alterations in their expression may reveal markers of disease susceptibility. Bronchoalveolar lavage fluid was sampled in weaned and transported calves and ELF protein expression was compared to a control group of calves using two-dimensional electrophoresis (2DE). Serum and pulmonary haptoglobin were increased following stress concurrent with the number of blood neutrophils. Using 2DE, significant changes in expression were observed in spots identified by mass spectrometry as annexin A1 and A5, odorant-binding protein (OBP), isocitrate dehydrogenase, fibrinogen, heme-binding protein, alpha-2-HS-glycoprotein, alpha-1-antichymotrypsin and albumin. Quantification of OBP mRNA by real-time RT-PCR and OBP protein by western blot revealed gender-dependent differences in relative OBP expression in response to stress. These findings reveal stress-associated protein changes in pulmonary ELF and suggest a mechanism through which stress alters respiratory disease susceptibility.     

Pinch-induced behavioral inhibition ('clipnosis') in domestic cats

Research has documented immobilization of rodents, rabbits, guinea pigs and dogs by mechanical means, typically using neck clips or inversion ('animal hypnosis'). In contrast, only a few studies of mechanical immobilization of cats are available, although some success has been reported in the literature. Domestic cats may be effectively immobilized by clips placed along the animal's dorsum. We use the term 'pinch-induced behavioral inhibition' (PIBI) for this behavior because it describes both the method and the response, while avoiding the more anthropomorphic term 'hypnosis'. We investigated the effectiveness of PIBI and its neurological and habituation effects in healthy cats and cats with idiopathic cystitis (IC). Although not all cats were susceptible to PIBI and effectiveness varied among individuals, PIBI was useful for gentle restraint in most cats.