Effect of background serum lithium concentrations on the accuracy of lithium dilution cardiac output determination in dogs

OBJECTIVES: To assess the effect of increasing serum lithium concentrations on lithium dilution cardiac output (LiDCO) determination and to determine the ability to predict the serum lithium concentration from the cumulative lithium chloride dosage. ANIMALS: 10 dogs (7 males, 3 females). PROCEDURE: Cardiac output (CO) was determined in anesthetized dogs by measuring LiDCO and thermodilution cardiac output (TDCO). The effect of the serum lithium concentration on LiDCO was assessed by observing the agreement between TDCO and LiDCO at various serum lithium concentrations. Also, cumulative lithium chloride dosage was compared with the corresponding serum lithium concentrations. RESULTS: 44 paired observations were used. The linear regression analysis for the effect of the serum lithium concentration on the agreement between TDCO and LiDCO revealed a slope of -1.530 (95% confidence interval [CI], -2.388 to -0.671) and a y-intercept of 0.011 (r2 = 0.235). The linear regression analysis for the effect of the cumulative lithium chloride dosage on the serum lithium concentration revealed a slope of 2.291 (95% CI, 2.153 to 2.429) and a y-intercept of 0.008 (r2 = 0.969). CONCLUSIONS AND CLINICAL RELEVANCE: The LiDCO measurement increased slightly as the serum lithium concentration increased. This error was not clinically relevant and was minimal at a serum lithium concentration of 0.1 mmol/L and modest at a concentration of 0.4 mmol/L. The serum lithium concentration can be reliably predicted from the cumulative lithium dosage if lithium chloride is administered often within a short period.     

Detection of canine microalbuminuria using semiquantitative test strips designed for use with human urine

Background — Commercial testing for microalbuminuria in human urine is often performed with point-of-care semiquantitative test strips followed by quantitative testing when indicated. An ELISA that quantifies canine urine albumin concentration has been developed, but semiquantitative test strips for use in the dog are not available.
Objective — The purpose of this study was to prospectively determine the concordance of canine urine albumin concentrations measured by a commercial human test strip and by ELISA.
Methods — Urine samples were obtained from 67 dogs evaluated for a variety of clinical conditions. Dipstick urinalyses were performed on all samples; clinician discretion determined method of urine collection and performance of urine sediment examination and/or urine culture. Urine albumin concentration was determined using test strips (Clinitek Microalbumin, Bayer Corporation, Elkhart, Ind, USA), and results were compared with those obtained by ELISA.
Results — The Clinitek strips correctly determined albumin concentration in 42 of 67 (63%) urine samples tested. Concordance was lowest (48%) for dogs with microalbuminuria (10–300 μg/mL by ELISA). Clinitek strip sensitivity and specificity for correct identification of microalbuminuria were 48% and 75%, respectively. Concordance was lower in dogs with urinary tract infection or hematuria and in samples collected by catheterization. Sensitivity and specificity for correct identification of microalbuminuria after exclusion of dogs with urinary tract infection or hematuria were 59% and 83%, respectively.
Conclusion — These results suggest that the Clinitek strips lack sufficient concordance with results obtained by ELISA to be reliable screening tests for microalbuminuria in the dog. A reliable semiquantitative point-of-care test for canine urine albumin concentrations below those detected by standard urine dipsticks is still needed.     

Right Dorsal Colitis

Moderate to severe ulcerative colitis of the right dorsal colon was diagnosed by necropsy or by exploratory celiotomy and biopsy in 13 horses with a primary clinical complaint of either colic, diarrhea, or weight loss. Clinical signs varied from acute fulminating diarrhea (possibly with fever), colic, dehydration, endotoxic shock and death, to a chronic condition manifested by mild intermittent colic up to several months in duration, and weight loss with or without mild diarrhea. In a large percentage of the horses, those affected had been hypovolemic and received nonsteroidal anti-inflammatory drugs (NSAID) or had received inappropriately high doses of phenylbutazone before the onset of illness. Experimental treatment of two horses with high doses of a phenylbutazone oral paste preparation (6 gm once daily for 5 days) and limitation of their water intake to approximately one half of maintenance requirement (for 5 days) resulted in reproduction of ulcerative colitis involving only the right dorsal colon, which was apparent at necropsy examination 11 and 15 days after initiation of drug use. It was concluded that localized ulcerative lesions in the right dorsal colon may be a previously unreported manifestation of toxicity due to the administration of NSAID.     

Distribution and depletion of [14C]resmethrin isomers administered orally to laying hens

The cis and trans isomers of the synthetic pyrethroid resmethrin, labelled with radiocarbon in either the alcohol or acid moiety, were individually administered orally to White Leghorn laying hens at a dosage of 10 mg kg^?1. With each isomer and label position, greater than 90% of the radiocarbon was eliminated in the excreta within 24 h after the treatment. Radiocarbon residues in the egg white and yolk fractions were low, with peak levels observed 1 and 4-5 days after treatment in white and yolk, respectively. In birds sacrificed 12 h after treatment, radiocarbon residues in tissues were low; the highest levels were found in the liver and kidney.     

Changes in wood properties at the boundary of polyporus amarus decay pockets

Summary Incense cedar heartwood infected by the pocket rot fungus Polyporus amarus was subjected to microtensile testing and miscroscopical examination to determine effects of this fungus upon wood substance adjacent to advanced decay pockets. Although springwood of the annual ring nearest the decay pocket in some samples had a slightly lower tensile strength than springwood from the same ring but a distance from the pocket, the difference was not statistically significant. Microscopical examination revealed the presence of small, sparse bore holes and hyphae in approximately the same number inside and outside the advanced decay pockets, and in discolored regions of incipient decay. A few bore holes and hyphae were found in specimens from what was macroscopically considered to be sound wood. Polarized illumination revealed no evidence of diffusion of cellulolytic enzymes from the hyphae in regions other than within advanced decay pockets, but the small numbers of hyphae and bore holes observed in decay pockets indicated that considerable enzyme diffusion might be necessary for decay to procede. The data suggest that possible alteration of physical, mechanical, and chemical properties in wood substance surrounding decay pockets need not be a significant factor for consideration in utilization of pecky incense cedar.

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Zusammenfassung Kernholz von Zeder (Libocedrus decurrens), das von Polyporus amarus befallen worden war, wurde Mikro-Zugfestigkeitsprüfungen und einer mikroskopischen Durchmusterung unterworfen. Es sollten die Auswirkungen dieses Pilzbefalles auf jene Teile der Holzsubstanz geprüft werden, die unmittelbar an die Befallsstellen angrenzen. Das Frühholz eines Jahrringes, das einer Befallsstelle am nächsten lag, zeigte zwar bei einigen Proben eine geringfügig niedrigere Zugfestigkeit als das Frühholz desselben Jahrringes, das aber von der Befallsstelle weiter entfernt lag. Die Unterschiede waren jedoch statistisch nicht signifikant. Die mikroskopische Durchmusterung deckte das Vorhandensein von kleinen, etwas zerstreut liegenden Bohrlöchern und Hyphen auf, in etwa gleichgroßer Anzahl innerhalb und außerhalb der Stellen fortgeschrittenen Befalls und in den verfärbten Bereichen des beginnenden Befalls. Einige wenige Bohrlöcher und Hyphen wurden ferner in Proben festgetsellt, die bei makroskopischer Betrachtung gesund erschienen. Im polarisierten Licht ließ sich keine Diffusion von aus Hyphen stammenden celluloitischen Enzymen außerhalb der Befallsbereiche beobachten. Die wenigen Hyphen und Bohrlöcher, die in den Befallsstellen beobachtet werden konnten, gaben aber einen Hinweis darauf, daß bei der Ausbreitung eine beträchtliche Enzymdiffusion stattfinden muß. Die ermittelten Werte weisen darauf hin, daß die möglicherweise eintretende Änderung der physikalischen, mechanischen und chemischen Eigenschaften des Holzes in unmittelbarer Umgebung der Befallsstellen als wichtige Faktoren bei der Verarbeitung dieses Holzes beachtet werden müssen.

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Presented at the 1968 Forest Products Research Society Annual Meeting.     

Detection of Incipient Germination in Malting Barley with a Starch Viscosity Method and a Proposed Ethanol Emission Method

The risk of germination loss during storage in two‐row malting barley can be reduced by identifying grain lots that have undergone incipient germination (IG) during harvest. A method based on starch viscosity that utilizes a Rapid Visco Analyzer (RVA) is currently available for IG analysis. A new potential method, based on the measurement of ethanol emission (EE) from whole barley, may be more efficient and less expensive than the RVA procedure. Three storage experiments were performed: experiments 1 and 3 at 25°C and 80% rh, and experiment 2 in unheated, uninsulated buildings. Decline in germination energy (GE) varied from <1% to about 80% during storage. In experiments 1 and 3, R² for GE loss (expressed as [weeks to 5% loss of GE]^0.2) versus EE was 0.76 in both cases, whereas R² for GE loss versus RVA viscosity was 0.64 and 0.68, respectively. In experiment 2, the greatest loss of GE was associated with high temperatures and relative humidity in July and August. EE performed as well as RVA in the prediction of germination loss in all three trials. Although further evaluation of the EE method is required, it appears to be a promising alternative to the RVA technique.     

Long-term changes in forest floor processes in southern Appalachian forests

Soil nutrient concentrations decreased in an aggrading southern Appalachian forest over a 20-year period. Construction of nutrient budgets showed significant nutrient sequestration aboveground including increased forest floor mass. We hypothesized that the changes in forest floor mass resulted from decreased litter decomposition rates because of decreased litter quality. In 1992 and 1993, we repeated a litter decomposition experiment conducted in 1969 and 1970 to test this hypothesis. In addition, we examined microarthropod populations and functional groups as litter decomposed. For four of the five species tested, first-year decomposition rates were about the same in both experiments. Initial litter nutrient concentrations of P were lower in all tree species in the most recent sampling. N, Ca, and Mg concentrations also declined in some species. These declines often resulted in decreased nutrient release rates during decomposition. Microarthropod populations differed significantly among litter species, as well as between years (probably resulting from differences in growing-season rainfall). For some litter species we found significant relationships between microarthropod populations and nutrient concentration (primarily C and N); however, most r²-values were low. Data suggest that changes in forest floor mass probably resulted from decreased litter quality and that those changes may have an effect on microarthropod populations.