Radiopaque Markers to Evaluate Gastric Emptying and Small Intestinal Transit Time in Healthy Cats

Determinations of gastric emptying time (GET) and small intestinal transit time (SITT) are useful in detecting gastrointestinal motility disorders and partial obstructions of the pylorus or small intestine. Barium-impregnated, polyethylene radiopaque spheres with diameters of 1.5 mm and 5.0 mm have been developed for quantitative assessment of gastrointestinal transit.
The purpose of this study was to evaluate GET and SITT using these radiopaque spheres in 10 healthy cats. The cats were randomly assigned to 1 of 3 treatment groups: fasted, fed, and fed plus sedation (acetylpromazine maleate 0.10 mg/kg subcutaneously). A repeated measures study design was used.
The mean GETs of 50%, 75%, and 90% of the 1.5-mm and the 5-mm spheres in the unfed cats were 0.36, 0.58, and 0.74 hours, and 0.41, 0.68, and 1.02 hours, respectively. These values were significantly (P ±.05) more rapid than the GETs of 50%, 75%, and 90% of the 1.5-mm and 5-mm spheres of either the sedated fed cats (4.39, 5.68, 6.65 and 5.15, 5.99, 6.91 hours) or the unsedated fed cats (6.43, 8.12, 9.06 and 7.49, 8.49, 9.22 hours).
The mean GETs of 50% and 75% of the 1.5-mm and 5-mm and of 90% of the 1.5-mm spheres were significantly ( P ±.05) more rapid in sedated than in unsedated fed cats. The GET of 50% of the 1.5-mm spheres was significantly more rapid ( P ±.05) than that of the 5-mm spheres in the fed cats. The mean SITTs, which ranged from 2.25 to 3.05 hours, were not significantly different ( P > .05) among the treatment groups or between the 1.5-mm and 5-mm spheres.
The GET of spheres given to fasted cats is significantly more rapid than that of fed cats. Subcutaneous injection of acetylpromazine speeds GET in fed cats. The SITT of small and large spheres was not influenced by feeding or by acetyl-promazine injection.     

Comparison of Continuous Versus Intermittent Enteral Feeding in Dogs

In humans, continuous intragastric feeding has been suggested to cause fewer gastrointestinal (GI) adverse effects, better weight gain and nitrogen balance, and less glucose intolerance than bolus feeding. The aim of this study was to compare the GI adverse effects and the metabolic and nutritional consequences of intragastric feeding of an enteral formula (Jevity; Ross Laboratories, Columbus, OH) intermittently or continuously to dogs. Using a cross-over study design, 10 healthy dogs were randomly assigned to be fed Jevity via gastrostomy tube either continuously (CFI or in 3 bolus meals/day (IF) for 10 days. The dogs were weighed daily. Serum chemistry and glucose tolerance tests (GlT were performed before and after each 10–day trial period. Fecal dry matter (FDM), serum osmolality (sOsm), and serum electrolytes (sElec) were determined 5 times during each 10 day trial period. Urine specific gravity was checked intermittently. Hydrogen breath tests were performed on days 0, 3, and 10. During the last 6 days of each trial period, nitrogen balance and digestibility of the Jevity were determined. There were no GI adverse effects noted on either protocol, and no significant ( P > .05) differences in body weights, serum chemistry results, sElec, sOsrn, GTT, hydrogen breath tests, digestibility trials, or nitrogen balance. There was a significant (P < .051 decrease in FDM over time for both protocols, and a significant (P < .051 increase in urine volume for IF compared with CF. In summary, there were no significant differences between treatments in weight maintenance, GI adverse effects, GTT, nitrogen balance, or feed digestibility. Changes in FDM suggest that the dogs received excess water. In conclusion, this study of healthy dogs provides no support for the preferential use of continuous intragastric feeding over bolus feeding. J Vet Intern Med 1996;10:133–138. Copyright © 1996 by the American College of Veterinary Internal Medicine .     

In vitro biomechanical comparison of dynamic compression plates with a rough contact surface and a polished contact surface for fixation of osteotomized equine third metacarpal bones

Objectives: To compare the number of cycles to failure of 4.5 mm broad dynamic compression plates (DCP), 4.5 mm broad limited‐contact dynamic compression plates (4.5‐LC‐DCP), and 5.5 mm broad limited‐contact dynamic compression plates (5.5‐LC‐DCP) having a rough (denoted by a prefix R‐) versus a standard smooth contact surface for the fixation of osteotomized equine 3rd metacarpal (MC3) bones. Study Design: Experimental. Animal Population: Fifteen pairs of adult equine cadaveric MC3 bones. Methods: Fifteen pairs of equine MC3 were divided into 3 test groups (5 pairs each) for comparison of (1) R‐DCP fixation with DCP fixation, (2) R‐4.5‐LC‐DCP fixation with 4.5‐LC‐DCP fixation, and (3) R‐5.5‐LC‐DCP fixation with 5.5‐LC‐DCP fixation to repair osteotomized equine MC3 bones under palmarodorsal 4‐point bending cyclic fatigue testing. For each group an 8‐hole plate with rough contact surface was applied to the dorsal surface of one randomly selected bone from each pair and a corresponding 8‐hole plate with smooth contact surface was applied dorsally to the contralateral bone from each pair. All plates and screws were applied using standard ASIF techniques. All MC3 bones had mid‐diaphyseal osteotomies. Mean number of cycles to failure for each method were compared using a paired t‐test within each group. Significance was set at P<.05. Results: Mean cycles to failure ± standard deviation was significantly greater for the R‐DCP fixation (230,025 ± 23,129) compared with the DCP fixation (103,451 ± 14,556), for the R‐4.5‐LC‐DCP fixation (99,237 ± 14,390) compared with the 4.5‐LC‐DCP fixation (46,464 ± 6325) and for the R‐5.5‐LC‐DCP fixation (65,113 ± 7796) compared with the 5.5‐LC‐DCP fixation (34,224 ± 3835). Conclusion: For the fixation of osteotomized MC3 bones, the constructs with plates having rough contact surface were superior to the corresponding constructs with plates having standard smooth contact surfaces in resisting cyclic fatigue under palmarodorsal 4‐point bending.     

Central diabetes insipidus in a cat with central nervous system B cell lymphoma

A 6-year-old male neutered cat presented with blindness, lethargy, polydipsia, hyposthenuria and severe hypernatraemia. Central diabetes insipidus was demonstrated by means of a low measured anti-diuretic hormone (ADH) concentration in the face of hypernatraemia, and clinical response to supplementation with desmopressin. Magnetic resonance imaging of the brain showed a discrete mass in the region of the hypothalamus. The cat was euthanased and post-mortem histological examination demonstrated B cell lymphoma involving the brain, optic nerves, urinary bladder wall and diaphragm. To the authors' knowledge, this case report is the first to describe central diabetes insipidus caused by central nervous system lymphoma in the cat.     

Administration divided over OECD biotech plan

For the past two years, members of the Organization for Economic Cooperation and Development (OECD)--which includes the United States, most of its European allies, and Japan--have been discussing how to set up international guidelines to regulate the emerging biotechnology industry. A May 1985 first draft of the guidelines spawned many objections, and now a revised draft, called "Safety and Regulations in Biotechnology," has encountered mixed responses from U.S. federal agencies. The Environmental Protection Agency generally supports the document, but the State Department, Food and Drug Administration, and Department of Agriculture have significant objections to its tone and substance, particularly in regard to the specificity of safety controls over the commercial development of recombinant DNA organisms used in large-scale production and for agricultural purposes.     

Analysis of major phospholipid species and ergosterol in fermenting industrial yeast strains using atmospheric pressure ionization ion-trap mass spectrometry

Knowledge of the individual lipid species that are associated with ethanol tolerance in Saccharomyces cerevisiae is necessary to understand potential mechanisms of how this organism uses these molecules to mitigate the toxic effects of ethanol. Three industrial yeast strains with varying degrees of ethanol tolerance were examined utilizing normal phase high-performance liquid chromatography and atmospheric pressure ionization-ion-trap mass spectrometry methods to quantitatively determine phospholipid and ergosterol levels at numerous fermentation time points. Both high and low Brix fermentations were performed to assess the sugar utilization capabilities of the strains. The results indicated that the strain with the most robust fermentation characteristics had the highest phosphatidylinositol levels and lowest phosphatidylcholine levels. Examination of the phospholipid structural data from tandem MS experiments indicated that the levels of several phospholipid species were unique to the slowest fermenting strain. The relation of ergosterol and other phospholipids to ethanol tolerance is also discussed.     

Another threat to fetal research

A bill introduced in the 97th Congress by Representative William Dannemeyer would prohibit the use of federal funds for experimentation on living fetuses except to insure the survival of the fetus or infant. Pro-life groups are supporting the bill; critics claim it is poorly worded, will prevent needed research, and is unnecessary because existing NIH regulations on fetal research are adequate.     

Chinese decry dishonesty in scientific research

Chinese journals are reporting instances of misconduct by researchers similar to those that have been troubling the American scientific community. Several articles are cited which report cases of fabrication of data, plagiarism, or unfair claims to authorship. A Chinese scientific journal has begun a regular column on ethics in science, and researchers have drafted a code of ethics for the Peking scientific community.     

Characterizing the Saltol Quantitative Trait Locus for Salinity Tolerance in Rice

This study characterized Pokkali-derived quantitative trait loci (QTLs) for seedling stage salinity tolerance in preparation for use in marker-assisted breeding. An analysis of 100 SSR markers on 140 IR29/Pokkali recombinant inbred lines (RILs) confirmed the location of the Saltol QTL on chromosome 1 and identified additional QTLs associated with tolerance. Analysis of a series of backcross lines and near-isogenic lines (NILs) developed to better characterize the effect of the Saltol locus revealed that Saltol mainly acted to control shoot Na⁺/K⁺ homeostasis. Multiple QTLs were required to acquire a high level of tolerance. Unexpectedly, multiple Pokkali alleles at Saltol were detected within the RIL population and between backcross lines, and representative lines were compared with seven Pokkali accessions to better characterize this allelic variation. Thus, while the Saltol locus presents a complex scenario, it provides an opportunity for marker-assisted backcrossing to improve salt tolerance of popular varieties followed by targeting multiple loci through QTL pyramiding for areas with higher salt stress.