Serotypes and intimin types of intestinal and faecal strains of eae+ Escherichia coli from weaned pigs

Enteropathogenic Escherichia coli (EPEC) that are known to cause severe diarrhoea in children and young rabbits are well characterized, but there are few reports on the serotypes and intimin (eae) types of EPEC in weaned pigs. Based on detection of the eae gene by PCR and by DNA-hybridisation with LEE specific gene probes, 20 intestinal and 17 faecal eae(+) strains from diarrhoeal (164) and non-diarrhoeal (57) weaned pigs from 13 Hungarian farms, representing 12.8% of diarrhoeal and 14.0% of non-diarrhoeal pigs, were identified. The dominant serotype was O123:H11 (40%) among intestinal, and O108:H9 (23%) among faecal strains. The majority (85%) of the intestinal strains possessed eae-beta and 10% carried eae-gamma gene. In contrast, significantly (p<0.025) fewer faecal strains (53%) harboured the eae-beta gene, and 23% were eae-gamma positive. In vitro adhesion tests of intestinal and faecal eae(+) strains indicated adhesion of 20/37 of the strains to PK15 (porcine kidney) cells while only 3/37 strains adhered to HeLa cells. The ultrastructure of intimate bacterial attachment of representative porcine eae(+) strains to PK15 cells showed no pedestal formation, in contrast to the human EPEC (O127:H5, eae-alpha) strain. In conclusion, the data do not demonstrate a significant role for the eae(+)E. coli in porcine post-weaning diarrhoea, but provide new information on a dominant porcine serotype (O123:H11, eae-beta), and on differences of serotypes and intimin types of porcine eae(+) strains according to their site of isolation. Furthermore there was an indication that the PK15 cell line could be used as a model to study in vitro adherence of eae(+)E. coli of some human and porcine origin.     

Muscle Potassium Content and Potassium Gluconate Supplementation in Normokalemic Cats With Naturally Occurring Chronic Renal Failure

Muscle potassium content and supplementation with potassium gluconate were evaluated in normokalemic cats with chronic renal failure (CRF). Affected cats received standard medical therapy for renal failure and either placebo (sodium gluconate! or potassium gluconate. At the beginning of the study and after 6 months of supplementation, glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were estimated using ³H-inulin and ¹⁴C-tetraethylammo-nium bromide (TEA) clearances. Muscle potassium content was determined in biopsy specimens using atomic absorption spectroscopy. Muscle biopsy samples obtained from cats with CRF before treatment had significantly lower muscle potassium content than did those from normal control cats. Over the 6-month period of supplementation, muscle potassium content increased both in cats with CRF that received potassium gluconate and in those that received placebo (sodium gluconate). Serum potassium concentration and fractional excretion of potassium remained relatively unchanged in both groups of cats throughout the treatment period. There were no significant differences in the percentage change in GFR and ERPF between treatment groups over the 6-month time period. Median values for pH, HCO₃, and total CO₂ at 6 months were higher than baseline in the potassium gluconate group but lower than baseline in the sodium gluconate group.     

Low-dose cyclophosphamide selectively decreases regulatory T cells and inhibits angiogenesis in dogs with soft tissue sarcoma

Background: Low‐dose, continuous (metronomic) chemotherapy improves tumor control by inhibiting tumor angiogenesis and suppressing regulatory T cells (Treg) in mice and humans. The effects of metronomic chemotherapy on Treg and tumor angiogenesis in dogs has not been investigated previously. Objective: To determine whether metronomic cyclophosphamide (CYC) therapy decreases Treg or exhibits antiangiogenic activity or both in dogs with soft tissue sarcoma (STS). We hypothesized that Treg numbers would be increased in dogs with STS and that continuous dosing of CYC would decrease Treg in a dose‐dependent manner, as well as exhibit antiangiogenic activity. Animals: Eleven client‐owned dogs with grade I or II STS. Twenty‐one healthy dogs were used as controls. Methods: Prospective, open, clinical trial. Dogs with STS were enrolled in 2 dose cohorts and administered CYC at 12.5 or 15 mg/m² PO once daily for 28 days. Whole blood and tumor biopsy specimens were obtained on days 0, 14, and 28 to assess changes in T lymphocyte subsets by flow cytometry and tumor microvessel density (MVD), respectively. Results: Administration of CYC at 12.5 mg/m²/d significantly decreased the number of Treg from days 0 to 28, but there was no change in the percentage of Treg or tumor MVD. In dogs that received CYC at 15.0 mg/m²/d, both the number and percent of Treg as well as tumor MVD were significantly decreased over 28 days. Conclusions: CYC administered at 15 mg/m²/d should be used in further studies examining the antitumor properties of low‐dose CYC in dogs.     

Prediction of fat percentage within marbling score on beef longissimus muscle using 3 different fat determination methods

Consumers are concerned with fat consumption from meat products, and the ability to determine fat has changed with recent technological advances. The objective of this study was to predict fat percentage within marbling scores and compare 3 fat analysis procedures. Steaks (n = 119) were selected by USDA grading system using an E + V Vision Grading camera at a commercial beef plant during 1 d. Two samples per carcass were cut from the 13th rib, both sides, and transported to the University of Missouri meat laboratory. The sample from the right side of the carcass was allotted to Warner-Bratzler shear force, and the sample from the left side, which was graded by the camera, was allotted to fat extraction. Warner-Bratzler shear force samples were cut into 2.54-cm steaks and aged for 14 d. Steaks allotted to fat extraction were trimmed of all external fat and twice ground using 8- and 4-mm grinding plates. The finely ground beef was then split into its allotted fat-extraction methods. The 3 methods used in fat extraction were 2:1 chloroform/methanol (Folch), ether-extractable fat (ether), and microwave drying and nuclear magnetic resonance (CEM). Warner-Bratzler shear force values were not different between marbling scores (P > 0.05). Regardless of fat extraction method, fat percentage increased as marbling score increased (P < 0.05). All regression equations for fat percentage, regardless of extraction method, were linear. Prediction equation for fat percentage using CEM was -3.46 + 0.016 (marbling score), R(2) of 0.824 (P < 0.0001). Prediction equation for fat percentage using ether was -3.08 + 0.017 (marbling score), R(2) of 0.859 (P < 0.0001). Prediction equation for fat percentage using Folch was -3.42 + 0.019 (marbling score), R(2) of 0.816 (P < 0.0001). When the CEM, Folch, and ether methods were compared, CEM and Folch regression lines had different slopes (P < 0.05). The slope of the regression line for ether was not different (P > 0.05) from CEM or Folch. Overall, ether is the most accurate method based on the R(2) value, but CEM is environmentally safe and the fastest method for determining total crude fat percentage.     

Increased monocyte chemotactic protein-1 concentration and monocyte count independently associate with a poor prognosis in dogs with lymphoma

Overexpression of the chemokine monocyte chemotactic protein-1 (MCP-1) has been associated with a poor prognosis in many human cancers. Increased MCP-1 concentrations may promote tumour progression by increasing mobilization of myeloid derived suppressor cells such as immature monocytes and neutrophils. We hypothesized that increased numbers of peripheral neutrophils or monocytes and increased MCP-1 concentrations would predict a worse outcome in dogs with multicentric lymphoma. In this retrospective study involving 26 client-owned dogs diagnosed with lymphoma, we show that peripheral neutrophil and monocyte counts as well as serum MCP-1 concentrations were significantly elevated relative to healthy control animals, and that such increases were associated with a decreased disease-free interval in dogs treated with chemotherapy based on cyclophosphamide, vincristine, doxorubicin and prednisone (CHOP). To our knowledge, this is the first study showing that pretreatment evaluation of monocyte and neutrophil counts can provide important prognostic information in dogs with lymphoma. The mechanisms underlying these observations remain to be determined.     

PD‐1 expression by canine T cells and functional effects of PD‐1 blockade

The co‐inhibitory checkpoint molecule programmed death receptor 1 (PD‐1) can trigger T cell functional exhaustion upon binding to its ligand PD‐L1 expressed on tumour cells or macrophages. PD‐1 blocking antibodies have generated remarkable results in human cancer patients, including inducing durable responses in a number of advanced cancers. Therefore, monoclonal antibodies specific for canine PD‐1 were assessed for T cell binding and induction of functional activation. A total of 5–10% of CD4 T cells and 20–25% of CD8 T cells from healthy dogs expressed PD‐1, and PD‐1 expression was upregulated on T cells from dogs with cancer. Functionally, PD‐1 antibodies significantly enhanced T‐cell activation, as assessed by proliferation and interferon‐gamma (IFN‐γ) production. PD‐1 antibodies also reversed T‐cell suppression induced by canine soluble PD‐L1 and by tumour cells and tumour explant fragments. These findings indicate that PD‐1 antibodies have potential for use in cancer immunotherapy in dogs.     

Hypokalemia in cats: 186 cases (1984-1987)

Retrospective review of serum biochemical data obtained from 501 cats over a 3-year period (1984-1987) indicated that 186 (37%) had hypokalemia (serum potassium concentration less than 4.1 mEq/L). After adjusting for disease diagnosis, cats fed either of 2 commercial diets were 4 times more likely to be hypokalemic than cats fed other diets. Odds ratios (OR; measure of association), adjusted for diet type, were calculated to determine the odds of hypokalemia for a given disease, compared with odds of normokalemia for the same disease. Chronic renal failure (OR = 14.4), hepatic disease (OR = 5.7), systemic infectious diseases (viral or bacterial; OR = 2.7), and neuromuscular or CNS disease (OR = 2.4) were all significantly associated (P less than 0.05) with the occurrence of hypokalemia. Significant differences in age or sex between hypokalemic and normokalemic cats were not found. Within the group of 186 hypokalemic cats, hypercholesterolemia (89 cats; 48%), hyperglycemia (88 cats; 47%), high serum urea nitrogen concentration (86 cats; 46%), hyperchloridemia (80 cats; 43%), and high serum creatinine concentration (73 cats; 39%) were the most common biochemical abnormalities. When disease diagnosis was compared among cats with severe hypokalemia (serum potassium concentration less than 3.0 mEq/L) and those with moderate hypokalemia, cats with severe hypokalemia were 3.5 times more likely to have chronic renal failure than cats with less severe hypokalemia.(ABSTRACT TRUNCATED AT 250 WORDS)