Ionized calcium concentration in horses with surgically managed gastrointestinal disease: 147 cases (1988-1990).

Packed cell volume, total plasma protein, serum sodium, potassium, and ionized Ca2+ concentrations, and blood pH were determined at the time of admission and following surgery in 147 horses with acute abdominal crisis. Horses were allotted to 3 categories on the basis of the surgical lesion: (1) nonstrangulating obstruction of the ascending or descending colon (category A, n = 76), (2) strangulating and nonstrangulating infarction of the cecum or ascending colon (category B, n = 37), and (3) strangulating and nonstrangulating infarction of the small intestine (category C, n = 25). Horses with low serum ionized Ca2+ concentration following surgery were given 23% calcium gluconate (100 to 300 ml) IV to effect, and ionized Ca2+ concentration was determined following treatment. The serum ionized Ca2+ concentrations of horses in categories A, B, and C before and after surgery were lower than our normal laboratory reference range. Prior to surgery, serum ionized Ca2+ concentration measured from horses in category B and C was lower than that in horses in category A. There was no difference in ionized Ca2+ concentration in serum samples obtained before surgery in horses from category B and C, and in serum samples obtained following surgery. There was a decrease in ionized Ca2+ concentration during surgery in horses in category A. There was no change between preoperative and postoperative ionized Ca2+ concentration in the samples obtained from horses in category B and C. After calcium gluconate administration, all horses with low serum ionized Ca2+ after surgery had concentrations within our normal range. Measurement of serum ionized Ca2+ in horses with an acute abdominal crisis is recommended.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preliminary results of an anticircumsporozoite DNA vaccine trial for protection against avian malaria in captive African black-footed penguins (Spheniscus demersus).

Captive juvenile African black-footed penguins (Spheniscus demersus) housed in an outdoor enclosure at the Baltimore Zoo have an average 50% mortality from avian malarial (Plasmodium sp.) infection each year without intense monitoring for disease and chemotherapeutic intervention. During the 1996 malaria transmission season, the safety and efficacy of an anti-circumsporozoite (CSP) DNA vaccine encoding the Plasmodium gallinaceum CSP protein against P. relictum were studied. The goal was to reduce clinical disease and death without initiating sterile immunity after release into an area with stable, endemic avian malaria. The birds were monitored for adverse clinical signs associated with vaccination, the stimulation of an anti-CSP antibody response, and protection afforded by the vaccine. The presence of P. relictum in trapped culicine mosquitoes within the penguin enclosure was monitored to assess parasite pressure. Among the vaccinated penguins, the parasitemia rate dropped from approximately 50% to approximately 17% despite intense parasite pressure, as determined by mosquito infection rate. During the year of the vaccine trial, no mortalities due to malaria occurred and no undesirable vaccination side effects occurred. This is the first trial of an antimalarial vaccine in a captive penguin colony.     

Performance assessment and validation of a paramagnetic particle-based enzyme-linked immunosorbent assay for chlorpyrifos in agricultural runoff waters

A commercial magnetic particle-based enzyme-linked immunosorbent assay (ELISA) kit for the insecticide chlorpyrifos [O,O-diethyl-O-(3,5,6-trichloro-2-pyridyl) phosphorothioate] was evaluated for its specificity, precision, and accuracy, its susceptibility to matrix interferences in agricultural and environmental surface waters, and its comparability to a gas chromatographic/flame photometric (GC/FPD) method for the determination of organophosphorus pesticides in natural waters. Repeatability, reproducibility, and accuracy studies show that the kit satisfies current U.S. Environmental Protection Agency criteria for the assessment of analytical methods. Observable matrix effects were found to be present in all of the environmental test waters, with the slopes of calibration curves generated in each of the test matrices deviating from that of the control matrix by as much as 16%. Specificity studies indicate that the chlorpyrifos polyclonal antibody adequately differentiates the target compound from other structurally similar organophosphorus pesticides, with the exception of its methyl analogue. Cross-reactivity with chlorpyrifos-methyl was approximately 37%, while reactivity with diazinon, pyridaphenthion, diclofenthion, bromiphos-ethyl, bromiphos-methyl, pirimiphos-ethyl, and chlorpyrifos oxon ranged from 1.6 to 10.7%. Cross-reactivity with pirimiphos-methyl, 3,5,6-trichloro-2-pyridinol, diethyl phosphate, and diethyl thiophosphate was negligible (<1%). Validation of the paramagnetic particle ELISA format was accomplished using water samples from two monitoring studies that were collected, split, and analyzed directly by ELISA and by GC/FPD. Results of the two analytical methods were then compared using standard t tests, regression analysis, and differences against mean measurement (bias) plots. While the agreement between the two methods was determined to be satisfactory, ELISA exhibits consistent positive bias in environmental matrices. Several preanalysis mitigation steps were suggested that may help moderate bias, but additional study is recommended to explicate the exact factors responsible for its consistent overestimation of results.     

Marine Pseudovibrio sp. as a Novel Source of Antimicrobials

Antibiotic resistance among pathogenic microorganisms is becoming ever more common. Unfortunately, the development of new antibiotics which may combat resistance has decreased. Recently, however the oceans and the marine animals that reside there have received increased attention as a potential source for natural product discovery. Many marine eukaryotes interact and form close associations with microorganisms that inhabit their surfaces, many of which can inhibit the attachment, growth or survival of competitor species. It is the bioactive compounds responsible for the inhibition that is of interest to researchers on the hunt for novel bioactives. The genus Pseudovibrio has been repeatedly identified from the bacterial communities isolated from marine surfaces. In addition, antimicrobial activity assays have demonstrated significant antimicrobial producing capabilities throughout the genus. This review will describe the potency, spectrum and possible novelty of the compounds produced by these bacteria, while highlighting the capacity for this genus to produce natural antimicrobial compounds which could be employed to control undesirable bacteria in the healthcare and food production sectors.     

Ascorbic acid determination in processed potatoes

A method to determine ascorbic acid at any stage of potato processing was developed. Potato samples are frozen in dry ice, lyophilized and analyzed using a modified spectrophotometric method. This method is simple, accurate, inexpensive and has a detection limit of 1.2 mg ascorbic acid/100 g dry weight potatoes.     

The aetiology of spinal deformity in Atlantic salmon, Salmo salar L.: influence of genetic factors on the frequency and severity in freshwater stages

A radiographic study was carried out on 2-year groups of pre-smolt parr to detect the comparative frequency of vertebral change in a range of defined pedigreed families of high growth rate of Atlantic salmon, Salmo salar L., reared under identical conditions. The observed frequency of deformity was related to the observed deformity level in the seawater parental generation, and to a potentially uncontrolled environmental determinant, i.e. stripping date. High and low parental deformity groups of families were found to produce offspring that had very similar levels of radiographically detectable spinal deformities in the pre-smolt parr, suggesting no genetic link. With regard to stripping date, the overall incidence was nearly half that seen in the preceding year (8.7% cf 16.6%). However, a non-significant trend to fewer radiographic spinal deformities was seen in the later stripping period.     

Ovarian remnant removal using minimally invasive laparoscopic techniques in four dogs

Four partially intact, female dogs with a median age of 6 · 5 years were presented to Angell Animal Medical Center for laparoscopic treatment of ovarian remnant syndrome. Dogs were positioned in dorsal recumbency and a three‐port laparoscopic technique was used to identify and remove en bloc any abnormal tissue in the area of the ovarian pedicles. None of the dogs required conversion to open coeliotomy and there were no major complications. Abnormal tissue, including granulosa thecal cell tumour (n = 1), was identified bilaterally in three dogs and unilaterally in one dog. Clinical signs associated with ovarian remnant syndrome resolved in all dogs following surgery.     

In-situ soil organic matter studies using scanning electron microscopy and low temperature ashing

The in-situ distribution and morphology of organic materials located on, or near, structural surfaces within some soils is examined on a submicroscopic scale by comparing scanning electron microscope images of the same areas of soil samples before and after low temperature ashing. Electron-translucent organic matter coatings up to 1/2 μm thick, and thinner, electron-opaque organic matter coatings were found on structural surfaces within these soils. Oribatid faecal pellets in one of the soils were found to contain aluminosilicate clay minerals. Fine-clay sized spheres of biogenic opaline silica were found to be contained within the epidermis of a decaying root. These studies show that the combined use of low temperature ashing and scanning electron microscopy will be a valuable technique for in-situ investigations of submicroscopic organic matter within soils.