Cryptic bioluminescence in a midwater shrimp

The mesopelagic shrimp Sergestes similis emits ventrally directed bioluminescence that closely matches the intensity of downward-directed illumination and is able to rapidly modify its light output to match changes in background intensity. Masking experiments show that the photoreceptors involved are the compound eyes or adjacent tissues. Light emission originates from modified portions of the hepatopancreas and is similar to oceanic light in angular distribution and spectral characteristics. Normally oriented animals respond minimally to upward-directed light.     

Sulphur isotope ratios in water,air, soil and vegetation near teepee creek gas plant,Alberta

Baseline data relevant to assessing environmental impact of continued operation of the Teepee Creek gas plant or other similar future industrial operations included S concentrations, pH of soil and water, and S isotope determinations. Concentrations evaluated the S loading. while isotope determinations identified sources of environmental S. The industrial source was very enriched in ³⁴S(δ³⁴S = +24%.) while soil and vegetation were characterized by ³⁴S depletions (δ³⁴S values as low as ?20%.. mean value near ?8%.). Thus S isotope determinations provided an excellent tool for environmental assessment in the region. It was found that the following are the more significant observations:

1. Neither the pH data nor S isotope compositions of the water or soil samples reveal measurable S loading by the industrial operation.
2. The measured atmospheric SO₂ concentrations are well below permitted air quality standards.
3. Data from an atmospheric sampling array revealed that the directions of highest SO₂ concentrations did not correspond to the direction of the gas processing plant nor did high concentrations relate isotopically to the emissions.
4. In both soil and vegetation samples, increase of S concentration was identified isotopically with mineral layers in the sub-surface and not with the industrial operation.

Thus it is concluded that S in the environment surrounding the Teepee Creek gas plant was dominated by sources other than the plant emissions.     

Anatomic and volumetric characterization of the cisterna chyli using CT lymphangiography and computer‐assisted design software in dogs with idiopathic chylothorax

The objectives of this retrospective, observational study were to characterize the anatomical features of the cisterna chyli (CC) in a cohort of dogs diagnosed with idiopathic chylothorax that underwent CT lymphangiography (CTLa), and to evaluate the feasibility of computer‐assisted design (CAD) software to quantify volumetric measurements of the CC. Twenty‐three client‐owned dogs with idiopathic chylothorax were included. Additionally, CTLa was performed in three canine cadavers to assess the ability of CAD software to accurately acquire volumetric measurements. Injection sites, attenuation values, anatomic location, dimensions, and aortic diameter to CC ratio (Ao:CC) were recorded. Video records of video‐assisted thoracic surgery (VATS) thoracic duct ligation (TDL) were reviewed in eight out of 23 dogs to compare operative and CTLa findings. The CC was dorsal and right‐sided in 18 out of 23 dogs, located between L1 and L4 in 21 dogs, and extended as far cranially as T11 in two dogs. The median measurements for length, height, and width were 150.0, 5.5, and 13.3 mm, respectively. Median total volume was 1.82 mL. Median volumes to the right and left of the aorta were 1.46 and 0.49 mL, respectively (P = .014). Median total CC volume to body weight ratio (CC:bw) was 0.07 mL/kg. The presence of an intrathoracic CC was observed intraoperatively in six out of eight cases that underwent VATS TDL. Findings supported the use of CTLa and CAD as feasible methods for characterizing the CC in dogs diagnosed with chylothorax. These methods may facilitate interventional planning involving the CC such as embolization.     

HIGH DOSE NARCOTIC ANAESTHESIA USING SUFENTANIL IN SWINE AND DOGS

Abstract: Protocols for utilizing intravenous infusions of sufentanil were developed for experimental cardiac surgery in swine and dogs. After initial experiences with fentanyl, sufentanil was selected for these procedures due to its increased potency and shorter half life thus requiring a smaller volume for infusion and more control. In dogs with experimental mitral valve regurgitation, an initial bolus of sufentanil 3 γg/kg IV was followed by a continuous IV infusion at a rate of 9–13 γg/kg/hr. Swine used in experiments involving cardiac conduction system ablation received ketamine 33 mg/kg IM and acepromazine 1.1 mg/kg IM as a preanesthetic combination. Following the preanesthetic, an initial infusion of sufentanil 15 γg/kg/hr was started and a loading dose of sufentanil 7 γg/kg IV was administered as a bolus for induction. They were then maintained by a continuous IV infusion at a rate of 15–30 γg/kg/hr. Dogs but not pigs required periodic supplementation of anaesthesia with isoflurane and/or nitrous oxide during portions of the experimental protocol. No anaesthetic related deaths have occurred in either species using these anaesthetic protocols for cardiac procedures.     

Surgical management of left-divisional intrahepatic portosystemic shunts: outcome after partial ligation of, or ameroid ring constrictor placement on, the left hepatic vein in twenty-eight dogs (1995-2005)

OBJECTIVES: To evaluate outcome in dogs with left divisional intrahepatic portosystemic shunts (PSS) treated by partial ligation (PL) or ameroid ring constrictor (ARC) placement on the left hepatic vein. DESIGN: Retrospective study. ANIMALS: Dogs (n=28) with left divisional intrahepatic PSS. METHODS: Retrieved data from medical records of dogs with left divisional intrahepatic PSS that had PL (n=17) or ARC (n=11) were signalment, history, clinical signs, preoperative blood work, portal pressure measurements, ARC size, complications and postoperative technetium scintigraphy. Outcome assessed by owner interview 6 months-10 years after surgery was classified as excellent, good or poor. Differences were tested by exact chi2 test. RESULTS: Major complications occurred in 3 dogs: coagulopathy (1 PL dog died), ascites (1 PL dog survived) and seizures (1 ARC dog died). Eight PL dogs had technetium portal scintigraphy; 1 dog was negative and 7 dogs positive for persistent shunting. Seven ARC dogs had scintigraphy; 4 dogs were negative and 3 positive for persistent shunting. In PL dogs, long-term clinical outcome was excellent (92%) or good (8%) whereas, in ARC dogs it was excellent (20%), good (50%) or poor (30%). This outcome difference between treatment groups was significant (P=.0012). CONCLUSION: Dogs treated by PL had significantly better long-term outcome compared with ARC treated dogs. CLINICAL RELEVANCE: Based on these data, ARC placement on the left hepatic vein in dogs with left-divisional intrahepatic PSS cannot be recommended.     

Successful transmission of a retrovirus depends on the commensal microbiota

To establish chronic infections, viruses must develop strategies to evade the host's immune responses. Many retroviruses, including mouse mammary tumor virus (MMTV), are transmitted most efficiently through mucosal surfaces rich in microbiota. We found that MMTV, when ingested by newborn mice, stimulates a state of unresponsiveness toward viral antigens. This process required the intestinal microbiota, as antibiotic-treated mice or germ-free mice did not transmit infectious virus to their offspring. MMTV-bound bacterial lipopolysaccharide triggered Toll-like receptor 4 and subsequent interleukin-6 (IL-6)-dependent induction of the inhibitory cytokine IL-10. Thus, MMTV has evolved to rely on the interaction with the microbiota to induce an immune evasion pathway. Together, these findings reveal the fundamental importance of commensal microbiota in viral infections.