A longitudinal study of lymphocyte subsets in a cohort of cats naturally-infected with feline immunodeficiency virus

Despite the potential of feline immunodeficiency virus (FIV) as an animal model for human immunodeficiency virus (HIV) studies, the long term effects of naturally-occurring infection have not been determined. HIV infection causes an ongoing deterioration in immune function which directly correlates with disease, in particular acquired immunodefciency syndrome (AIDS). However, it is not known whether FIV-induced immunosuppression is progressive or related to the clinical condition. This study examined changes in lymphocyte subset numbers of serial samples, taken from cohorts of FIV-positive and FIV-negative cats over an 18-month period. FIV-positive cats were clinically staged as asymptomatic carriers (AC) or cats with AIDS-related complex (ARC), and FIV-negative cats matched and staged on the basis of similar diseases. During the course of the study, 4 FIV-positive cats developed AIDS, classed as the terminal stage of infection. There were no significant differences in the mean absolute numbers of any lymphocyte subset between the onset (to) and the completion (t18) of the study. Similarly there were no significant changes in subset numbers during the 18 months preceding the development of AIDS. While the study period was brief and the sample sizes small, it is postulated that FIV infection in Australia may not necessarily cause progressive immunodeficiency and that FIV-induced immunosuppression (as measured by subset analysis) may not be well correlated with the clinical status of the infected cat.     

Determination of Safe Depth of Pin Penetration for Repair of Distal Femoral Physeal Fractures in Immature Dogs: A Comparison of Normograde and Retrograde Pin Placement

Objective —The purpose of this study was to determine the depth that implants may be safely placed into the distal femoral epiphysis (DFE) for the repair of distal femoral physeal fractures.
Study Design —The depth of the DFE was related to the radiographic thickness of the patella in this experimental study.
Animals or Sample Population —Twenty immature canine cadavers.
Methods —Patella thicknesses were measured from lateral radiographs. Actual DFE depths were determined for pins driven in normograde fashion and for pins driven retrograde from the central depression between the metaphyseal pegs and from the cranial pegs. The association of DFE depth and patella thickness was evaluated using linear regression analysis. Using 95% confidence intervals, rules for estimating the safe depth of implant placement into the DFE were determined.
Results —DFE depth had significant correlation with patella thickness for pins placed in retrograde fashion from the central depression between the metaphyseal pegs (r²= .83) and from the cranial pegs (r²= .82) and for pins placed in normograde fashion (r²= .65).
Conclusions —Based on 95% confidence intervals, pins placed in retrograde fashion from the central depression between the metaphyseal pegs may be safely driven into the DFE a distance equal to 140% of patella thickness. Pins placed from the cranial metaphyseal pegs may be driven to a depth equal to 80% of patella thickness, and pins placed in normograde fashion may be driven to a depth equal to 30% of patella thickness.
Clinical Relevance —Measurement of patella thickness assists the surgeon in determining the approximate depth that pins may be driven into the DFE without penetrating the articular surface of the stifle joint.     

Conservative management of minimally displaced radial fractures in three horses

Minimally displaced, spiral, radial fractures were diagnosed in three adult horses. Two horses had open fractures and in one horse the fracture was closed. A diagnosis was made on radiographs taken 24 h, 5, and 9 days after the fracture. There was minimal displacement of the fracture fragments despite the considerable time which had elapsed between fracture and diagnosis and an unfavourable prognosis with internal fixation, so conservative therapy was the preferred method of treatment. One horse developed a sequestrum and draining sinus, which was treated surgically under general anaesthesia 3 months after diagnosis of the fracture. Other complications were minimal and transient. Two horses were being used for pleasure riding 12 months after fracture and one horse was pasture sound at 8 months.     

DOPPLER MEASUREMENT OF SPLANCHNIC BLOOD FLOW DURING DIGESTION IN UNSEDATED NORMAL DOGS

The purpose of this study was to measure splanchnic blood flow during digestion in unsedated dogs by using duplex Doppler sonography. The study population consisted of 12 healthy dogs. Blood flow in the cranial mesenteric artery, the celiac artery, and the aorta was measured before a test meal and at 20, 60, and 90 minutes after eating. The following measurements were made or calculated: vessel diameter, peak systolic velocity, end diastolic velocity, mean velocity, resistive index, pulsatility index, and flow volume. There was a significant postprandial decrease in the resistive and pulsatility indices in both the cranial mesenteric (preprandial RI = 0.867, postprandial RI = 0.796, preprandial PI = 3.033, postprandial PI = 2.173) and the celiac (preprandial RI = 0.854, postprandial RI = 0.769, preprandial PI = 2.639, postprandial PI = 1.930) arteries. In both vessels the end diastolic velocity, the mean velocity, and the flow volume increased significantly postprandially. These changes occurred significantly earlier in the celiac artery than in the cranial mesenteric artery. The findings most likely correspond to postprandial splanchnic vasodilation. Doppler ultrasound provide a good methode of detecting changes in postprandial splanchnic blood flow in the dog.     

Common sequence variants in the LOXL1 gene confer susceptibility to exfoliation glaucoma

Glaucoma is a leading cause of irreversible blindness. A genome-wide search yielded multiple single-nucleotide polymorphisms (SNPs) in the 15q24.1 region associated with glaucoma. Further investigation revealed that the association is confined to exfoliation glaucoma (XFG). Two nonsynonymous SNPs in exon 1 of the gene LOXL1 explain the association, and the data suggest that they confer risk of XFG mainly through exfoliation syndrome (XFS). About 25% of the general population is homozygous for the highest-risk haplotype, and their risk of suffering from XFG is more than 100 times that of individuals carrying only low-risk haplotypes. The population-attributable risk is more than 99%. The product of LOXL1 catalyzes the formation of elastin fibers found to be a major component of the lesions in XFG.     

Spontaneous formation of macroscopic chiral domains in a fluid smectic phase of achiral molecules

A smectic liquid-crystal phase made from achiral molecules with bent cores was found to have fluid layers that exhibit two spontaneous symmetry-breaking instabilities: polar molecular orientational ordering about the layer normal and molecular tilt. These instabilities combine to form a chiral layer structure with a handedness that depends on the sign of the tilt. The bulk states are either antiferroelectric-racemic, with the layer polar direction and handedness alternating in sign from layer to layer, or antiferroelectric-chiral, which is of uniform layer handedness. Both states exhibit an electric field-induced transition from antiferroelectric to ferroelectric.     

Uncertainty and adaptive management for biodiversity conservation

Adaptive management of natural resources is widely supported, but in biodiversity conservation there have been few practical applications of the approach in its entirety. Some of the contributions to this special publication examine progress in the implementation of adaptive approaches into conservation policy, while others explore novel theoretical and modeling approaches that seek to accommodate the complexities of real-world applications. Several of the papers address the treatment of uncertainty in adaptive management through innovative approaches to experimentation and monitoring, use and characterisation of expert knowledge and reconciliation of differences of opinion about parameters or systems. Drawing on these contributions, we discuss the major impediments to implementing adaptive management, why adaptive management has been slow to be implemented and how this can be redressed.