Exposure to the Neurotoxic Dinoflagellate,Alexandrium catenella,Induces Apoptosis of the Hemocytes of the Oyster,Crassostrea gigas

This study assessed the apoptotic process occurring in the hemocytes of the Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs) producer. Oysters were experimentally exposed during 48 h to the toxic algae. PSTs accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. Results show a significant increase of the number of hemocytes in apoptosis after 29 h of exposure. Two pro-apoptotic genes (Bax and Bax-like) implicated in the mitochondrial pathway were significantly upregulated at 21 h followed by the overexpression of two caspase executor genes (caspase-3 and caspase-7) at 29 h, suggesting that the intrinsic pathway was activated. No modulation of the expression of genes implicated in the cell signaling Fas-Associated protein with Death Domain (FADD) and initiation-phase (caspase-2) was observed, suggesting that only the extrinsic pathway was not activated. Moreover, the clear time-dependent upregulation of five (Bcl2, BI-1, IAP1, IAP7B and Hsp70) inhibitors of apoptosis-related genes associated with the return to the initial number of hemocytes in apoptosis at 48 h of exposure suggests the involvement of strong regulatory mechanisms of apoptosis occurring in the hemocytes of the Pacific oyster.     

Bioactivity-guided fractionation of the lipoxygenase and cyclooxygenase inhibiting constituents from Chisocheton polyandrus Merr

Lipoxygenase (LOX)-inhibiting compounds from the leaves of Chisocheton polyandrus Merr. were isolated in this study using a bioactivity-guided fractionation technique. Two dammarane triterpenoids, dammara-20,24-dien-3-one (1) (IC(50)=0.69±0.07 μM) and 24-hydroxydammara-20,25-dien-3-one (2) (IC(50)=1.11±0.38 μM), were isolated and identified based on the soybean LOX assay. Dammara-20,24-dien-3-one (1) exhibited dual inhibition of both human 5-LOX (IC(50)=24.27±2.92 μM) and cyclooxygenase-2 (COX-2) (IC(50)=3.17±0.90 μM), whereas 24-hydroxydammara-20,25-dien-3-one (2) did not exhibit any significant inhibitory effects. This report is the first to detail the inhibition of LOX and COX by both C. polyandrus and its isolated compounds.     

Intrahepatic portosystemic venous shunt in a neonatal roan antelope (Hippotragus equinus cottoni).

A 6-day-old, female roan antelope (Hippotragus equinus cottoni) was diagnosed with a single intrahepatic portosystemic venous shunt at necropsy. Clinical signs had included weakness, lethargy, hypothermia, diarrhea, and a weak suckle response. Multiple seizure episodes were associated with hypoglycemia and characterized by vocalization, muscle fasciculations, and disorientation. Hematologic abnormalities included anemia with hypochromasia, anisocytosis, poikilocytosis, and leukopenia with neutropenia and lymphopenia. Serum biochemical abnormalities included elevations in blood urea nitrogen and total serum bile acid concentration. A portosystemic vascular anomaly should be a differential diagnosis for nonthriving, exotic ruminant calves with overt or subtle neurologic signs, persistent hypoglycemia, and/or elevated bile acids. In very young calves, total bile acid concentration may be more useful in establishing a diagnosis than blood ammonia concentration.     

The effect of dystocia on physiological and behavioral characteristics related to vitality and passive transfer of immunoglobulins in newborn Holstein calves

The objective of this study was to examine the effect of calving difficulty or dystocia on the vitality of newborn calves and its association with blood pH, the apparent efficiency of immunoglobulin G (IgG) absorption (AEA), and weight gain. A total of 45 calving events (N = 48 calves) were monitored from the first sight of fetal membranes. All calves were assessed at the time of first attaining sternal recumbency (SR), at 2 and 24 h, and at 7 and 14 d of age. Measurements included time to SR, rectal temperature, respiration and heart rate, analysis of blood gases and other blood measures, suckling response, time to standing, passive transfer of IgG, and weight gain. Calves were separated from their dam 2 h after birth and fed a commercial colostrum replacer containing 180 g of IgG by esophageal tube feeder. Calves born following dystocia had lower venous blood pH and took longer to attain SR and attempt to stand than those born unassisted. Duration of calving interacted with the number of people required to extract the calf by pulling as a significant predictor of pH at SR. No association was found between pH at SR and AEA. However, reduced AEA was found in calves that were female and in calves that did not achieve SR within 15 min of birth. A longer calving duration, being born in July or August rather than June, and a shorter time spent standing in the first 2 d of life were significantly associated with reduced weight gain to 14 d. It was concluded that factors at calving impact the physiology, vitality, and subsequent weight gain of newborn calves.     

Azotemia and glomerular filtration rate in dogs with chronic valvular disease

BACKGROUND: Little information is available about the prevalence of renal dysfunction in dogs with chronic valvular heart disease (CVD). HYPOTHESIS: Azotemia and a decrease in glomerular filtration rate (GFR) are more severe with increased severity of CVD. ANIMALS: 124 (study No. 1) and 24 (study No. 2) client-owned dogs with CVD. METHODS: A retrospective study (study No. 1) was performed to assess the prevalence of azotemia in the New York Heart Association (NYHA) classes of heart failure in dogs with CVD. A prospective study (study No. 2) was then designed to determine GFR in dogs with different degrees of CVD severity. Complete physical examination, electrocardiography, blood pressure measurement, thoracic radiographs, echocardiography, and plasma and urine analyses were also performed. RESULTS: In study No. 1, 50% of the dogs were azotemic and the percentage of azotemic dogs increased with functional class (up to 70% in NYHA class IV patients). In study No. 2, 8/24 dogs were azotemic. Plasma urea and creatinine were higher in NYHA class III-IV dogs compared with class I-II dogs. The GFR was lower (P < .001) in NYHA class III-IV dogs (1.7 +/- 0.7 mL/min/kg) than in class I to II dogs (3.1 +/- 0.8 mL/min/kg). Only 1 dog in class I-II had a GFR below 2 mL/min/kg and only 2/9 class III-IV dogs had a GFR above 2 mL/min/kg. CONCLUSION AND CLINICAL RELEVANCE: Azotemia and renal impairment increase with the severity of congestive heart failure and are frequent findings in dogs with CVD. It remains to be shown if deterioration of renal function is a direct result of progression of the heart disease.     

Soricid response to coarse woody debris manipulations in Coastal Plain loblolly pine forests

We assessed shrew (soricids) response to coarse woody debris (CWD) manipulations in managed upland loblolly pine (Pinus taeda) stands in the upper Coastal Plain of South Carolina over multiple years and seasons. Using a completely randomized block design, we assigned one of the following treatments to 12, 9.3-ha plots: removal (n = 3; all CWD ≥ 10 cm in diameter and ≥60 cm long removed), downed (n = 3; 5-fold increase in volume of down CWD), snag (n = 3; 12-fold increase in standing dead CWD), and control (n = 3; unmanipulated). Therein, we sampled shrews during winter, spring, and summer seasons, 2003–2005, using drift-fence pitfall arrays. During 1680 drift-fence plot nights we captured 253 Blarina carolinensis, 154 Sorex longirostris, and 51 Cryptotis parva. Blarina carolinensis capture rate was greater in control than in snag treatments. Sorex longirostris capture rate was lower in removal than downed and control plots in 2005 whereas C. parva capture rate did not differ among treatments. Overall, the CWD input treatments failed to elicit the positive soricid response we had expected. Lack of a positive response by soricid populations to our downed treatments may be attributable to the early CWD decay stage within these plots or an indication that within fire-adapted pine-dominated systems of the Southeast, reliance on CWD is less than in other forest types.     

Prospective evaluation of complications associated with transesophageal echocardiography in dogs with congenital heart disease

BackgroundTransesophageal echocardiography (TEE) is useful in the assessment and procedural monitoring of congenital heart disease (CHD) with a relatively low complication rate in humans.ObjectivesTo evaluate the safety of TEE and report complications in dogs.AnimalsForty client‐owned dogs with CHD.MethodsProspective observational study including gastroesophagoscopy before and after TEE imaging. TEE was planned with a GE 6VT‐D adult probe in dogs weighing ≥4 kg and a GE 10T‐D microprobe alternating with an intracardiac echocardiography probe placed in the esophagus in dogs <4 kg. Difficulties with probe placement, probe interference and TEE probe imaging times were recorded. Dogs were monitored in the recovery period after TEE using an established nausea scoring system.ResultsNew gastroesophageal abnormalities were identified after TEE in 4 dogs including 4 areas of mucosal damage involving <25% of the lower esophageal sphincter (n = 4) and 1 lesion at the heart base (n = 1) and were not attributed to longer imaging times or a specific probe. Lesions identified before TEE in 4 dogs remained unchanged after TEE. The 6VT‐D probe could not be placed in 1 dog with enlarged tonsils, and it obstructed fluoroscopic views in 3 dogs. The probes did not compress any structures in dogs in which fluoroscopy was performed (n = 20). Four dogs had evidence to suggest nausea after the procedure.Conclusions and Clinical ImportanceWhile major complications remain possible, complications in this study were mild and few in number. Dog size and probe characteristics are factors to consider when performing TEE.