Capnographic documentation of nasoesophageal and nasogastric feeding tube placement in dogs

Objective: To evaluate the ability of capnography to document proper placement of nasoesophageal (NE) and nasogastric (NG) feeding tubes. This study was conducted in 3 phases. Phase I of this study was designed in order to test the efficacy of capnography to distinguish placement of a feeding tube in the alimentary tract versus the respiratory tract. Phase II was designed in order to document that carbon dioxide (CO₂) could be measured through a polyvinyl chloride (PVC) feeding tube. Phase III was performed in order to evaluate the technique of continuous monitoring during insertion of the feeding tube into the esophagus and stomach as would be performed during a clinical‐tube placement. Design: Prospective study. Setting: Research laboratory. Animals: 24 adult dogs. Interventions: In Phase I, sedated dogs were instrumented with an intratracheal catheter and an 8 French feeding tube placed nasally into the distal esophagus and later advanced into the stomach. In Phase II, dogs were anesthetized and an 8 French feeding tube was placed down the endotracheal tube, then into the esophagus and later advanced into the stomach. In Phase III, sedated dogs were instrumented with an 8 French feeding tube inserted intranasally and then advanced to the level of the nasopharynx, distal esophagus and, lastly, the stomach. Fluoroscopy was used in order to determine location of the feeding tube. Measurements and main results: Phase I measurements included respiratory rate and CO₂ from the trachea, esophagus, and stomach and pH of gastric fluid sample. Phase II measurements included respiratory rate and CO₂ from the endotracheal tube, feeding tube in the endotracheal tube, feeding tube in the distal esophagus, and feeding tube in the stomach. Phase III data collection included respiratory rate and CO₂ as the tube was passed through the nasal cavity, nasopharynx, esophagus and stomach. Phase I fluid samples were collected from 5 of the 9 dogs and had pH values from 1.68 to 4.20. In both phases, values for the respiratory rate and CO₂ from the esophagus and stomach were 0 ± 0, significantly lower (P < 0.001) than the values from the trachea. In Phase II, there was no significant difference between the respiratory rates (P = 0.886) and CO₂ (P = 0.705) readings obtained from the endotracheal tube compared to readings from the feeding tube in the endotracheal tube. In Phase III, there was a significant difference (P < 0.001) between the respiratory rates and CO₂ readings obtained from the nasal cavity and the nasopharynx when compared to those readings obtained from the esophagus and stomach. Measurement of CO₂ and respiratory rate resulted in a reading of 0 every time the feeding tube was in the esophagus or stomach. Conclusions: Capnography may be used in order to detect airway placement of NE and NG tubes.     

Production of primary cell cultures on a semi-industrial scale. 1. Modification of the trypsinization procedure--possible means to improve cell yield

To produce large quantities of primary cell suspensions on efficient technique is described which is named "Biomix-Method". By this technique first tissue mince is performed automatically using tissue amounts between 300 g and 500 g. Trypsinization takes place in a three-litre trypsinization vessel using a stirring mechanism according to a defined trypsinization mode. In regard to optimal cell seeding concentration and a justifiable productivity one kidney of newborn or suckling calf yields 6--9 1 cell suspension and that of piglet 1,8-2,3 1, respectively. Proliferation behaviour and effectivity of primary cells are discussed and compared with other cell systems.     

Association of hyponatremia and hyperglycemia with outcome in dogs with congestive heart failure

Objective: To evaluate plasma sodium and glucose concentrations in dogs with congestive heart failure (CHF) prior to treatment and evaluate the differences between survivors and non‐survivors. Design: Retrospective study. Animals: Fifty‐nine dogs with CHF prior to receiving cardiac medication. Interventions: None. Measurements and main results: The mean plasma sodium concentration in dogs with CHF was below the reference range (144–156 mmol/L) and significantly lower (P=0.009) in non‐survivors (141±6 mmol/L) compared with survivors (147±4 mmol/L). The mean plasma glucose concentration was above the reference range (76–117 mg/dL) and significantly higher (P=0.004) in non‐survivors (128±52 mg/dL) compared with survivors (100±13 mg/dL). Forty‐four percent of non‐survivors had concurrent low plasma sodium and high plasma glucose concentrations, whereas no survivors had both abnormalities (P<0.0001). Conclusions: Lower plasma sodium and higher plasma glucose are associated with a worse outcome in dogs with CHF.     

Interrelationships of erythrocyte glutathione peroxidase system enzymes in the fasted Beagle

Eight adult female Beagles were fasted for 21 days to investigate responses of the erythrocyte glutathione peroxidase system enzymes. Blood samples were collected once a week. Erythrocyte reduced glutathione was maintained within 10% of base-line value. Hexose monophosphate pathway dehydrogenases showed a significant inverse relationship to glutathione reductase (GR) activity. Further, active GR, as a percentage of total GR, increased as hexose monophosphate pathway dehydrogenase activity fell. A similar relationship between these enzymes has been reported in human glucose-6-phosphate dehydrogenase deficiency. Also, glutathione peroxidase showed an inverse linear response to erythrocytic reduced glutathione. Though the responses of this system are complex, they appear interrelated.     

Escherichia coli challenge and one type of smectite alter intestinal barrier of pigs

An experiment was conducted to determine how an E. coil challenge and dietary clays affect the intestinal barrier of pigs. Two groups of 32 pigs （initial BW： 6.9 ± 1.0 kg） were distributed in a 2 x 4 factorial arrangement of a randomized complete block design （2 challenge treatments： sham or E. coil, and 4 dietary treatments： control, 0.3% smectite A, 0.3% smectite B and 0.3% zeolite）, with 8 replicates total. Diarrhea score, growth performance, goblet cell size and number, bacterial translocation from intestinal lumen to lymph nodes, intestinal morphology, and relative amounts of sulfo and sialo mucins were measured. The E. coli challenge reduced performance, increased goblet cell size and number in the ileum, increased bacterial translocation from the intestinal lumen to the lymph nodes, and increased ileal crypt depth. One of the clays （smectite A） tended to increase goblet cell size in ileum, which may indicate enhanced protection. In conclusion, E. coli infection degrades intestinal barrier integrity but smectite A may enhance it.     

Microbial diffusion assay for antibiotics in feeds using a simplified design

Results are compared for the microbiological analysis of antibiotics in feeds using the AOAC plate diffusion assay and the simplified 2-plate assay. Five antibiotics, bacitracin, chlortetracycline, oxytetracycline, penicillin, and streptomycin, were used to supplement feed extracts at levels of 100 and 25 micrograms antibiotic/g feed (bacitracin at 100 micrograms/g only). For bacitracin at the one level and for penicillin at both levels, the 2-plate design yielded significantly more accurate results than those of the AOAC assay. The same was true for the 25 micrograms/g level of oxytetracycline and the 100 micrograms/g level of streptomycin. For streptomycin at the 25 micrograms/g supplementation, the AOAC assay results showed better accuracy. There was no significant difference in results between the 2 designs for oxytetracycline at 100 micrograms/g and chlortetracycline at either level. The accuracy and precision of the results for the 2-plate design are equivalent to or better than those obtained using the AOAC design; in addition, the 2-plate assay is less labor-intensive, is more cost-effective, and is able to determine reasonable conditions of similarity.     

Induction of phase II detoxification enzymes in rats by plant-derived isothiocyanates: comparison of allyl isothiocyanate with sulforaphane and related compounds

Plants of the family Brassicaceae contain high levels of glucosinolates. The latter compounds are degraded to isothiocyanates, some of which have been shown to be potent inducers of phase II detoxification enzymes in vitro. In the present study, the ability of six plant-derived isothiocyanates (allyl isothiocyanate, iberverin, erucin, sulforaphane, iberin, and cheirolin) to increase tissue levels of the phase II detoxification enzymes quinone reductase (QR) and glutathione S-transferase (GST) in a variety of rat tissues has been compared. At the low dose level employed (40 micromol/kg/day), cheirolin was without effect in any tissue. All of the other isothiocyanates, however, increased GST and QR activities in the duodenum, forestomach, and/or the urinary bladder of the animals, with the greatest effects being seen in the urinary bladder. With the exception of cheirolin, little difference was observed in the inductive activity of the various isothiocyanates. Phase II enzymes are known to protect against chemical carcinogenesis, and the selectivity of isothiocyanates in inducing such enzymes in the bladder is of interest in view of recent epidemiological studies showing a decreased incidence of cancer of this organ in individuals with a high dietary intake of Brassica vegetables.     

Diagnosis of gaucher's disease and niemann-pick disease with small samples of venous blood

Enzymes which catalyze the hydrolysis of glucocerebroside and sphingomyelin have been demonstrated in preparations of washed human white blood cells. The level of activity of these respective enzymes is markedly decreased in leukocyte preparations obtained from patients with Gaucher's and Niemann-Pick diseases. Assay of these enzymes may be useful in the differential diagnosis of the sphingolipidoses.