MAGNETIC RESONANCE, ULTRASOUND AND HISTOPATHOLOGIC CORRELATION OF ACUTE AND HEALING EQUINE TENDON INJURIES

Ultrasonography and MRI have become valuable tools for imaging of tendon injuries. The current study examines the histopathologic basis for the imaging abnormalities. Five injured equine forelimbs and two normal contralateral limbs were studied with high resolution real time ultrasound and MRI. Histologic sections were made and correlated with the diagnostic images. All lesions were readily seen by both modalities. Lesions characterized by hemorrhage, edma, and cellular infiltration were sonolucent on ultrasound and bright on MRI images. MRI returned to normal as fibrogenesis ensued. Ultrasound images remained abnormal until fibrillar reallgnment occured with completion of the healing process. High resolution real time ultrasound and MRI both accurately reflect the tissue abnormalities in acute tendon injuries. The injured horse does appear to be an effective model for correlative imaging studies of tendon injuries.     

Use of 64Copper Measurements to Diagnose Canine Copper Toxicosis

Inherited canine copper toxicosis is a serious problem in Bedlington terriers and West Highland White terriers, and may also be a problem in other less-studied breeds. Affected dogs become ill at midlife with progressive and ultimately fatal liver disease. Treatments for removal of copper and prevention of copper accumulation are available, but are most effective if begun before the dog becomes ill. Until recently diagnosis has not been available until the dog is 1 year of age, and then only by an invasive liver biopsy with determination of liver copper concentration. The authors studied the use of 64copper for early diagnosis of canine copper toxicosis. Two procedures were evaluated. The first involved measuring the concentration of 64copper in blood 24 hours after oral administration of the radioisotope. At this time, 64copper was associated primarily with ceruloplasmin secreted into the blood by the liver. This procedure is useful in the diagnosis of the human counterpart, Wilson's disease. However, the authors found it to be nondiscriminatory between affected and unaffected dogs. In contrast, the second procedure, which involved measuring 64copper excreted in stool during 48 hours after an intravenous dose of radioisotope, yielded results that differentiated most affected and unaffected dogs.     

USE OF 123IODINE METAIODOBENZYLGUANIDINE SCINTIGRAPHY FOR THE DIAGNOSIS OF A PHEOCHROMOCYTOMA IN A DOG

A 13-year-old neutered female Yorkshire terrier presented with a history of progressive episodic weakness and disorientation of 4 months duration. Physical and neurologic examinations were normal at presentation. Abdominal ultrasound revealed a mass involving the right adrenal gland. Standard planar scintigraphy was performed at 4, 18, and 24 hours after intravenous injection 185 MBq (5mCi) of ¹²³I-labeled metaiodobenzylguanidine (¹²³I-MIBG). An area of focal intense uptake was identified in the area of the right adrenal gland. A pheochromocytoma was confirmed histologically after surgical excision.     

Evaluation of Transmittance and Reflectance Pulse Oximetry in a Canine Model of Hypotension and Desaturation

Ten, anesthetized dogs were instrumented with three pulse oximeter probes; two lingual transmittance probes and one rectal reflective probe. Arterial oxygen desaturation was produced by decreasing the inspired oxygen concentration. Hypotension was produced with an infusion of nitroprusside. Simultaneous pulse oximeter readings (SpO₂) were compared to co-oximeter measured arterial saturation (SaO₂) collected over a range of SaO₂ (50–100%) and mean arterial pressures (40–100mmHg). Each of the monitors and means of evaluating SpO₂ studied provided accurate SpO₂ measurements over a range of mean arterial pressure from 40–100mmHg. All of the monitors tested tended to overestimate the SaO₂ when the arterial saturation was less than 70%.     

Apoplastic redox metabolism: Synergistic phenolic oxidation and a novel oxidative burst

The plant apoplast is an important mediator of communication between the cell cytoplasm and its surroundings. Plant cell suspensions offer a convenient model system to gain insight into apoplastic physiology. Here, we describe a novel phenomenon that took place when two naturally occurring phenolics were added together to either soybean or tobacco cell suspensions. Acetosyringone (AS) and/or hydroxyacetophenone (HAP), phenolics found in the extracellular/apoplast of tobacco cells, were added to soybean or tobacco cell suspensions undergoing an oxidative burst. Individually, AS appeared to be utilized as a typical peroxidase substrate to scavenge hydrogen peroxide, while HAP was utilized at a much lower rate. However, when added together the rate of utilization of both phenolics increased and surprisingly resulted in the production of hydrogen peroxide. We have further characterized this novel phenomenon in suspension cells. This study demonstrates that certain phenolics in plants can cause co-oxidation which, as in animals, could alter the structure and bioactivity of surrounding phenolics.     

Profile of Steroid Receptors and Increased Aromatase Immunoexpression in Canine Inflammatory Mammary Cancer as a Potential Therapeutic Target

Canine inflammatory mammary cancer (IMC) has been proposed as a model for the study of human inflammatory breast cancer (IBC). The aims of this study were to compare the immunohistochemical expression of aromatase (Arom) and several hormone receptors [estrogen receptor α (ERα), estrogen receptor β (ERβ), progesterone receptor (PR) and androgen receptor (AR)], in 21 IMC cases vs 19 non‐IMC; and to study the possible effect of letrozole on canine IMC and human inflammatory breast cancer (IBC) in vitro using IPC‐366 and SUM‐149 cell lines. Significant elevations of the means of Arom Total Score (TS), ERβ TS and PR TS were found in the IMC group (p = 0.025, p = 0.038 and p = 0.037, respectively). Secondary IMC tumours expressed higher levels of Arom than primary IMC (p = 0.029). Non‐IMC PR‐ tumours contained higher levels of Arom than non‐IMC PR+ tumours (p = 0.007). After the addition of letrozole, the number of IMC and IBC cells dropped drastically. The overexpression of Arom found and the results obtained in vitro further support canine IMC as a model for the study of IBC and future approaches to the treatment of dogs with mammary cancer, and especially IMC, using Arom inhibitors.     

Serum levels of reproductive steroid hormones in captive sand tiger sharks, <Emphasis Type="Italic">Carcharias</Emphasis><Emphasis Type="Italic">taurus</Emphasis> (Rafinesque), and comments on their relation to sexual conflicts

Levels of reproductively-related steroids were determined in captive male sand tiger sharks, Carcharias taurus, maintained at two institutions: SeaWorld Adventure Park Orlando and the National Aquarium in Baltimore. Sexual conflicts were absent at the former, but were documented at the latter. Serum titers of 17β-estradiol, progesterone, testosterone, and 5α-dihydrotestosterone were determined via radioimmunoassay in adult male sharks from 1988 to 2000. Sampling overlap between the two institutions occurred for 3 months of the year, but steroid concentrations were compared only for April due to the occurrence of sexual conflicts in the sharks at the National Aquarium in Baltimore in that month. For April, testosterone and dihydrotestosterone were significantly higher in the SeaWorld males, and progesterone was significantly higher in the National Aquarium in Baltimore males, while estradiol was not significantly different. Steroid levels were also determined from serial samples taken monthly over 17 months from three male sharks and one female shark at the National Aquarium in Baltimore in 2001–2002 and were compared with corresponding observed sexual conflicts. The steroid levels obtained showed distinct annual hormonal cycles in the male sharks and corroborated a biennial cycle for the single serially-sampled female shark. Furthermore, the steroid levels for individual males correlated with sexual conflicts as well as their position within the male dominance hierarchy. As this species is depleted in some regions globally, insight into the steroid profile of mature sand tiger sharks is important for a greater understanding of the relationship between their reproductive physiology and behavior, and may aid in captive management and reproduction. L. E. L. Rasmussen—Deceased.     

Renal myxozoanosis in weedy sea dragons, Phyllopteryx taeniolatus (Lacepède), caused by Sinuolinea phyllopteryxa n. sp.

Renal myxozoanosis was diagnosed histologically in 11 captive, wild caught, adult weedy (common) sea dragons, Phyllopteryx taeniolatus, from three separate public aquaria in the United States. Myxozoan spores were visible in wet mounts of kidney tissue and were associated with renal tubular dilatation and tubular epithelial cell hypertrophy. Light and electron microscopy revealed spore morphology consistent with the genus Sinuolinea. Spores were spheroidal, slightly dorso-ventrally compressed, length (L) 17.1 x width (W) 16.4 x thickness (T) 15.6 microm, with two shell valves joined at a distinct, sinuous sutural ridge, and had two nearly spherical polar capsules, L 5.5 x W 5.0 microm, with five to seven turns of the polar filament. There were no extra-valvular ridges or protrusions. DNA sequencing required the design of three new primers that yielded 1740 bp of 18S ribosomal DNA sequence. The parasite was determined to be novel based on morphological and molecular data, and was given the name Sinuolinea phyllopteryxa after its vertebrate host.     

Heavy Metal Contamination of Soil and Vegetation in the Vicinity of Industries in Bangladesh

Water, Air, &; Soil Pollution - A study was conducted to investigate the heavy metal contamination of soil and vegetation in the vicinity of industries around Dhaka city in Bangladesh....     

Major bacterial contribution to marine dissolved organic nitrogen

Next to N2 gas, the largest pool of reduced nitrogen in the ocean resides in the enormous reservoir of dissolved organic nitrogen (DON). The chemical identity of most of this material, and the mechanisms by which it is cycled, remain fundamental questions in contemporary oceanography. Amino acid enantiomeric ratios in the high molecular weight fraction of DON from surface and deep water in three ocean basins show substantial enrichment in D enantiomers of four amino acids. The magnitude and pattern of these D/L enrichments indicate that peptidoglycan remnants derived from bacterial cell walls constitute a major source of DON throughout the sea. These observations suggest that structural properties of specific bacterial biopolymers, and the mechanisms for their accumulation, are among the central controls on long-term cycling of dissolved organic nitrogen in the sea.