Period prevalence and mortality rates associated with hypocholesterolaemia in dogs and cats: 1,375 cases.

To determine the period prevalence of hypocholesterolaemia and the associated mortality rates in dogs and cats at a university teaching hospital. The secondary aim was to identify disease processes associated with hypocholesterolaemia. MATERIALS AND METHODS: Medical records over a 5-year period were reviewed to determine the severity of hypocholesterolaemia and its associated mortality rate. Medical records of animals with moderate to severe hypocholesterolaemia (<2.59 mmol/L in dogs, <1.81 mmol/L in cats) were analysed further. Animals with hospital-acquired hypocholesterolaemia were identified. RESULTS: Among 16,977 dogs and 3,788 cats that had at least one cholesterol measurement, the period prevalence of hypocholesterolaemia was 7.0% in dogs and 4.7% in cats. The mortality rate of hypocholesteraemic dogs and cats was 12% in both species which was significantly higher than that of animals with normal serum cholesterol. The degree of hypocholesterolaemia was significantly associated with mortality. Dogs, but not cats, with hospital-acquired hypocholesterolaemia had a higher mortality rate than those presenting with hypocholesterolaemia. Disease of hepatic, gastrointestinal and lymphoreticular systems were most commonly associated with hypocholesterolaemia, and infectious and neoplastic disease were the most commonly associated pathophysiologic processes in both species. Lymphoma was over-represented in dogs with neoplasia. CLINICAL SIGNIFICANCE: Hypocholesterolaemia is not a frequent abnormality but was associated with mortality in this study and may be a negative prognostic indicator. It is not known if hypocholesterolaemia is simply a marker for disease severity, or if it is has active physiologic effects contributing to poor outcomes.

Assessment of Canine Pancreas-Specific Lipase and Outcomes in Dogs with Hemodialysis-Dependent Acute Kidney Injury.

BACKGROUND: Renal replacement therapies can be life-saving for dogs with severe acute kidney injury (AKI), however, comorbidities including pancreatitis might affect outcome. HYPOTHESIS/OBJECTIVES: To investigate the prevalence of pancreas-specific lipase (Spec cPL) measurements consistent with pancreatitis (≥400 µg/L) in dogs undergoing intermittent hemodialysis (IHD) for treatment of AKI and to determine whether there were associations between 30-days outcomes and Spec cPL measurements. ANIMALS: Fifty-three client-owned dogs presented to teaching hospitals between November 2008 and September 2016 that underwent IHD. METHODS: Retrospective medical record review from dogs that received IHD for management of AKI and also had a Spec cPL measurement. Association between survival, dialysis-dependency, and Spec cPL measurements was assessed. RESULTS: Forty of 53 (76%) dogs were alive at 30-days and 33/53(62%) had a Spec cPL result ≥400 µg/L. Spec cPL was not significantly different either between surviving (635.5 µg/L, range 29-1,001) and nonsurviving dogs (860 µg/L, range 56-1,001; P = 0.75) or between dialysis-dependent (1,001 µg/L, range 177-1,001) and nondialysis-dependent dogs (520 µg/L, range 29-1,001; P = 0.08). Spec cPL ≥400 µg/L was not significantly associated either with survival (P = 0.74) or dialysis-dependency (P = 0.33). CONCLUSIONS AND CLINICAL IMPORTANCE: Results revealed a high prevalence of Spec cPL ≥400 µg/L in dogs with AKI treated with IHD. No significant associations between Spec cPL and survival or dialysis-dependency in dogs with AKI at 30 days were identified in the current study, however, the latter could be due to lack of power in this study.

Antimicrobial Susceptibility Patterns in Urinary Tract Infections in Dogs (2010-2013).

BACKGROUND: Urinary tract infections (UTIs) are common in dogs. The responsible bacterial populations have evolved with increasing resistance to many antimicrobials. OBJECTIVE: To characterize the antimicrobial susceptibility patterns of canine urinary tract isolates over a 51-month period. ANIMALS: One thousand six hundred and thirty-six bacterial isolates from 1,028 dogs. METHODS: Aerobic bacterial isolate growth and susceptibility data from urine cultures of dogs were identified, retrospectively. Medical records were reviewed to obtain signalment, comorbidities, and antimicrobial use in the previous 30 days. The UTIs were further categorized as uncomplicated, complicated, or pyelonephritis. RESULTS: Common bacterial isolates identified were Escherichia coli (52.5%), Staphylococcus spp. (13.6%), and Enterococcus spp. (13.3%). In vitro susceptibility among all isolates varied for commonly prescribed antimicrobials (amoxicillin [59%], amoxicillin/clavulanic acid [76%], cephalexin [66%], enrofloxacin [74%] and trimethoprim-sulfamethoxazole [86%]). For all antimicrobials tested (except aminoglycosides), in vitro susceptibility was higher in uncomplicated versus complicated infections (P < .05). Uncomplicated infection isolate susceptibility rates remained ≤90% for PO administered antimicrobials. Administration of amoxicillin, doxycycline, and enrofloxacin, but not amoxicillin/clavulanic acid in the previous 30 days was associated with resistance to that antimicrobial. Multidrug resistant isolates of E. coli and Staphylococcus spp. were more common in dogs with complicated than uncomplicated UTIs (36% versus 21%, P < .0001). CONCLUSIONS AND CLINICAL IMPORTANCE: In vitro susceptibility was highly variable and no PO administered antimicrobial had >90% efficacy among isolates tested. Multidrug resistance was frequent among isolates tested suggesting that routine culture and susceptibility testing is indicated. Previously prescribed antimicrobials may affect empirical choices made pending susceptibility testing.

Incidence, severity and prognosis associated with hypernatremia in dogs and cats.

BACKGROUND: Hypernatremia has been associated with substantial morbidity and death in human patients. The incidence and importance of hypernatremia in dogs and cats has not been determined. HYPOTHESIS/OBJECTIVES: To describe the incidence of and prognosis associated with hypernatremia in dogs and cats at a university teaching hospital. ANIMALS: A total of 16,691 dogs and 4,211 cats with measured blood or serum sodium concentration. METHODS: Retrospective study. Medical records of animals with a blood or serum sodium concentration measured during a 60-month period were reviewed to determine the severity of hypernatremia and its associated case fatality rate. Cases with moderate (11-15 mmol/L above the reference range) or severe hypernatremia (≥16 mmol/L above the reference range) were further reviewed. RESULTS: A total of 957 dogs (5.7%) and 338 cats (8.0%) were diagnosed with hypernatremia. Case fatality rates of dogs and cats with hypernatremia was 20.6 and 28.1%, respectively compared to 4.4 and 4.5% with a normal blood or serum sodium concentration (P < .0001). The magnitude of hypernatremia was linearly associated with a higher case fatality rate (P < .0001). Hypernatremia was associated with a higher case fatality rate than hyponatremia. Among the animals with moderate or severe hypernatremia, 50% of dogs and 38.5% of cats presented with community-acquired hypernatremia, and 50% of dogs and 61.5% of cats developed hospital-acquired hypernatremia. CONCLUSIONS AND CLINICAL IMPORTANCE: Hypernatremia was found infrequently in this population but was associated with increased case fatality rates in dogs and cats. Presence and severity of hypernatremia might be useful as a prognostic indicator.

Accuracy of potassium supplementation of fluids administered intravenously.

BACKGROUND: Potassium (K+) supplementation of isotonic crystalloid fluids in daily fluid therapy is commonly performed, yet its accuracy in veterinary medicine is undetermined. OBJECTIVE: To investigate the accuracy of K+ supplementation in isotonic crystalloid fluids. ANIMALS: None. METHODS: Observational study. 210 bags of fluid supplemented with KCl being administered to hospitalized dogs and cats intravenously (IV) were sampled over a 3-month period. Measured K+ concentration ([K+]) was compared to the intended [K+] of the bag. In a second experiment, 60 stock fluid bags were supplemented to achieve a concentration of 20 mmol/L K+, mixed well and [K+] was measured. In another 12 bags of 0.9% NaCl, K+ was added without mixing the bag, and [K+ ] of the delivered fluid was measured at regular time points during constant rate infusion. RESULTS: The measured [K+] was significantly higher than intended [K+] (mean difference 9.0 mmol/L, range 6.5 to >280 mmol/L, P < .0001). In 28% of clinical samples measured [K+] was ≥5 mmol/L different than intended [K+]. With adequate mixing, K+ supplementation of fluids can be accurate with the mean difference between measured and intended [K+] of 0.7 (95% CI -0.32 to 1.7) mmol/L. When not mixed, K(+) supplementation of 20 mmol/L can lead to very high [K+] of delivered fluid (up to 1410 mmol/L). CONCLUSIONS AND CLINICAL IMPORTANCE: Inadequate mixing following K+ supplementation of fluid bags can lead to potentially life threatening IV infused [K+]. Standard protocols for K+ supplementation should be established to ensure adequate mixing.

Influence of needle gauge used for venipuncture on automated platelet count and coagulation profile in dogs.

OBJECTIVE: To determine if differing gauge (G) needles used for venipuncture altered the automated platelet count and coagulation profile (prothrombin time (PT) and activated partial thromboplastin time (aPTT)) in clinically healthy dogs. DESIGN: Prospective, observational, randomised, clinical study. METHODS: We enrolled 20 clinically healthy dogs. Blood was collected via direct venipuncture of the jugular veins with 21G, 23G and 25G needles in a random order. Automated haematology and automated coagulation times were performed on the blood samples. Values were analysed for differences among the needle gauges and also the order of sample collection. RESULTS: No difference was found in the automated platelet count or automated coagulation times for the three needle gauges used or the order in which the samples were collected. CONCLUSION: Venipuncture can be performed with a 21G, 23G or 25G needle to obtain blood from dogs for automated platelet count and PT/aPTT measurement without affecting the results.

Diagnostic yield of cytologic analysis of pericardial effusion in dogs.

BACKGROUND: Pericardial effusion cytology is believed by many to be of limited value, yet few studies have evaluated its diagnostic utility. OBJECTIVES: To determine the diagnostic utility of cytologic analysis of pericardial effusion in dogs and to determine if consideration of additional data could improve the diagnostic yield. ANIMALS: Two hundred and fifty-nine dogs with cytologic analysis of pericardial effusion performed between April 1990 and June 2012. METHODS: Electronic medical records from a university teaching hospital were retrospectively reviewed; signalment, complete blood count, serum biochemistry, cytologic analysis of pericardial effusion, and echocardiographic data were recorded. Cytology was classified as diagnostic (infectious or neoplastic) or nondiagnostic (hemorrhagic or other) and groups were compared with multiple Student's t-tests. RESULTS: Cytology was grouped as nondiagnostic (92.3%) or diagnostic (7.7%) and characterized as hemorrhagic (90%), neoplastic (4.6%), infectious (3.1%), or other (2.3%). Overall cytologic analysis of pericardial effusion diagnostic utility was 7.7% and increased to 20.3% if the effusion hematocrit (HCT) <10%; echocardiographic evidence of a mass did not result in a significant increase in the diagnostic utility. CONCLUSIONS AND CLINICAL IMPORTANCE: The diagnostic utility of cytologic analysis of canine pericardial effusion is variable depending on the underlying etiology. In this group of dogs, the diagnostic yield of cytologic analysis was greater for pericardial effusion samples in which the HCT was less than 10%.

Diagnostic utility of D-dimer concentrations in dogs with pulmonary embolism.

BACKGROUND: Pulmonary embolism (PE) is a complication of systemic disease in dogs. Antemortem diagnosis is challenging because of the lack of a confirmatory test. OBJECTIVES: To retrospectively determine the diagnostic utility of D-dimer concentrations in dogs with necropsy-confirmed PE. ANIMALS: Ten dogs with PE confirmed at necropsy that had D-dimer concentrations measured and 10 control dogs with D-dimer concentrations available that lacked PE on necropsy. METHODS: The computerized medical record database was searched for dogs with necropsy-confirmed PE that had D-dimer concentrations measured at that visit. An age-, sex-, and breed-matched control group was identified. Signalment, location of PE, and coagulation profiles were collected. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated using a D-dimer concentration of 250 ng/mL. RESULTS: Coagulation profiles were not different between dogs with and without PE. Using 250 ng/mL as a cut-off D-dimer concentration, the sensitivity and specificity were 80 and 30%, respectively, for the diagnosis of PE. The NPV and PPV were 60 and 53.0%, respectively. D-dimer concentration <103 ng/mL had 100% sensitivity for ruling out PE and no value was 100% specific. CONCLUSIONS AND CLINICAL IMPORTANCE: D-dimer concentrations <250 ng/mL have a high sensitivity for the absence of PE, but PE still can occur in dogs with a normal D-dimer concentration. Increased D-dimer concentrations are not specific for PE.

Incidence, nature, and etiology of metabolic alkalosis in dogs and cats.

BACKGROUND: The incidence and causes of metabolic alkalosis in dogs and cats have not been fully investigated. OBJECTIVES: To describe the incidence, nature, and etiology of metabolic alkalosis in dogs and cats undergoing blood gas analysis at a veterinary teaching hospital. ANIMALS: Dogs and cats at a veterinary medical teaching hospital. METHODS: Acid-base and electrolyte results for dogs and cats measured during a 13-month period were retrospectively collected from a computer database. Only the first measured (venous or arterial) blood gas analyzed in a single hospitalization period was included. Animals with a base excess above the reference range for the species were included. RESULTS: A total of 1,805 dogs and cats were included. Of these, 349 (19%) were identified as having an increased standardized base excess, 319 dogs and 30 cats. The mixed acid-base disorder of metabolic alkalosis with respiratory acidosis was the most common abnormality identified in both dogs and cats. Hypokalemia and hypochloremia were more common in animals with metabolic alkalosis compared to animals without metabolic alkalosis. The 4 most commonly identified underlying diseases were respiratory disease, gastrointestinal tract obstruction, furosemide administration, and renal disease. CONCLUSIONS AND CLINICAL IMPORTANCE: Metabolic alkalosis was less common than metabolic acidosis in the same population of animals. Evidence of contraction alkalosis was present in many patients in this study. Hypokalemia and hypochloremia were more frequent in patients with metabolic alkalosis and suggest the importance of evaluation of acid-base status in conjunction with serum electrolyte concentrations.

Comparative accuracy of several published formulae for the estimation of serum osmolality in cats.

OBJECTIVE: To determine the osmole gap utilizing 18 previously published formulae for the estimation of serum osmolality in cats. PROCEDURES: Serum samples were frozen at -80°C after routine biochemical analysis. An Advanced Micro Osmometer 3300 was used to measure serum osmolality. Eighteen previously reported formulae were used to calculate osmolality from biochemical analysis results. The calculated osmolality was subtracted from the measured osmolality to determine the osmole gap. Osmole gaps for azotaemic and hyperglycaemic cats were compared to those from cats without azotaemia or hyperglycaemia using each formula. RESULTS: The osmole gaps varied dependent on the formula used and the presence or absence of hyperglycaemia or azotaemia. Eleven formulae led to calculated osmolality and osmole gaps that were not statistically different when hyperglycaemia, azotaemia or both were present. Four of these 11 formulae resulted in osmole gaps near zero. For each formula used, the osmole gap increased with increasing osmolality. CLINICAL SIGNIFICANCE: Multiple formulae to calculate serum osmolality can be used, but they result in significantly different osmole gaps. Clinicians should be aware of the specific reference interval for the formula being used. The formula [2(Na(+) ) + glucose + BUN] is recommended as it is easy to use and reliable even in the presence of hyperglycaemia and/or azotaemia.

Incidence, nature, and etiology of metabolic acidosis in dogs and cats.

BACKGROUND: Metabolic acidosis is an important abnormality in ill and injured dogs and cats. OBJECTIVES: To describe the incidence, nature, and etiology of metabolic acidosis in dogs and cats that had arterial or venous blood gases measured for any reason at a university teaching hospital. ANIMALS: Dogs and cats at the Veterinary Medical Teaching Hospital. METHODS: Acid base parameters and electrolyte and lactate concentrations in dogs and cats measured during a 13-month period were retrospectively retrieved from a computer database. Metabolic acidosis was defined as a standardized base excess (SBE) in dogs of <-4 mmol/L and in cats <-5 mmol/L. RESULTS: A total of 1,805 dogs and cats were included; of these, 887 (49%) were classified as having a metabolic acidosis (753 dogs and 134 cats). Primary metabolic acidosis was the most common disorder in dogs, whereas mixed acid base disorder of metabolic acidosis and respiratory acidosis was most common in cats. Hyperchloremic metabolic acidosis was more common than a high anion gap (AG) metabolic acidosis; 25% of dogs and 34% of cats could not be classified as having either a hyperchloremic metabolic acidosis or a high AG metabolic acidosis. CONCLUSIONS AND CLINICAL IMPORTANCE: Metabolic acidosis was found commonly in this patient population and was associated with a wide variety of disease processes. Mixed acid base disorders occur frequently and routine categorization of metabolic acidosis based on the presence of high AG or hyperchloremia may be misleading in a large proportion of cases.

Prevalence and persistence of antibodies to herpes viruses, Chlamydia pneumoniae and Helicobacter pylori in Alaskan Eskimos: the GOCADAN Study.

The prevalence and persistence of antibodies against cytomegalovirus (CMV), herpes simplex virus types 1 (HSV1) and 2 (HSV2), Helicobacter pylori and Chlamydia pneumoniae were determined in Alaskan Eskimos. The study included 610 individuals (mean age 43 +/- 15 years; 45% males) participating in the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study. Archived serum samples and those collected during the GOCADAN study were analysed for antibodies against the above pathogens by ELISA. The current prevalence of antibody seropositivity was 94% to CMV, 90% to HSV1, 38% to HSV2, 80% to H. pylori, and 42% to C. pneumoniae. The persistence of antibodies (in both archived and current samples) against CMV, HSV1 and H. pylori was high (83%, 84% and 67%, respectively) compared with those against HSV2 (26%) and C. pneumoniae (29%). Moreover, the seroconversion rates to these organisms were low. Most individuals acquired CMV, HSV1 and H. pylori antibodies by the age of 24 years (94%, 90% and 72%, respectively), and >50% carried HSV2 and C. pneumoniae antibodies by the age of 45 years. There were gender differences in antibody seropositivity rates. Over 70% of individuals had antibodies to at least three of the five pathogens tested. The study demonstrated the high prevalence and lifelong persistence of multiple antibodies, suggesting chronic infections among Alaskan Eskimos.

Local delivery of marrow-derived stromal cells augments collateral perfusion through paracrine mechanisms.

BACKGROUND: Bone marrow cell therapy is reported to contribute to collateral formation through cell incorporation into new or remodeling vessels. However, the possible role of a paracrine contribution to this effect is less well characterized. METHODS AND RESULTS: Murine marrow-derived stromal cells (MSCs) were purified by magnetic bead separation of cultured bone marrow. The release of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), placental growth factor (PlGF), and monocyte chemoattractant protein-1 (MCP-1) was demonstrated by analysis of MSC conditioned media (MSC-CM). MSC-CM enhanced proliferation of endothelial cells and smooth muscle cells in a dose-dependent manner; anti-VEGF and anti-FGF antibodies only partly attenuated these effects. Balb/C mice (n=10) underwent distal femoral artery ligation, followed by adductor muscle injection of 1x10(6) MSCs 24 hours later. Compared with controls injected with media (n=10) or mature endothelial cells (n=8), distal limb perfusion improved, and mid-thigh conductance vessels increased in number and total cross-sectional area. MSC injection improved limb function and appearance, reduced the incidence of auto-amputation, and attenuated muscle atrophy and fibrosis. After injection, labeled MSCs were seen dispersed between muscle fibers but were not seen incorporated into mature collaterals. Injection of MSCs increased adductor muscle levels of bFGF and VEGF protein compared with controls. Finally, colocalization of VEGF and transplanted MSCs within adductor tissue was demonstrated. CONCLUSIONS: MSCs secrete a wide array of arteriogenic cytokines. MSCs can contribute to collateral remodeling through paracrine mechanisms.

Marrow-derived stromal cells express genes encoding a broad spectrum of arteriogenic cytokines and promote in vitro and in vivo arteriogenesis through paracrine mechanisms.

We recently demonstrated that marrow stromal cells (MSCs) augment collateral remodeling through release of several cytokines such as VEGF and bFGF rather than via cell incorporation into new or remodeling vessels. The present study was designed to characterize the full spectrum of cytokine genes expressed by MSCs and to further examine the role of paracrine mechanisms that underpin their therapeutic potential. Normal human MSCs were cultured under normoxic or hypoxic conditions for 72 hours. The gene expression profile of the cells was determined using Affymetrix GeneChips representing 12 000 genes. A wide array of arteriogenic cytokine genes were expressed at baseline, and several were induced >1.5-fold by hypoxic stress. The gene array data were confirmed using ELISA assays and immunoblotting of the MSC conditioned media (MSC(CM)). MSC(CM) promoted in vitro proliferation and migration of endothelial cells in a dose-dependent manner; anti-VEGF and anti-FGF antibodies only partially attenuated these effects. Similarly, MSC(CM) promoted smooth muscle cell proliferation and migration in a dose-dependent manner. Using a murine hindlimb ischemia model, murine MSC(CM) enhanced collateral flow recovery and remodeling, improved limb function, reduced the incidence of autoamputation, and attenuated muscle atrophy compared with control media. These data indicate that paracrine signaling is an important mediator of bone marrow cell therapy in tissue ischemia, and that cell incorporation into vessels is not a prerequisite for their effects.

Effects of hepatitis A vaccination on atherogenesis in a murine model.

Our laboratory demonstrated that seropositivity to hepatitis A virus (HAV) independently predicts risk for coronary artery disease (CAD). As these findings are based only on the presence of HAV-specific antibodies, and not infectious virus, this prompted questions regarding possible effects of HAV vaccines on CAD development. If seropositivity to HAV alone, resulting from HAV vaccination, leads to increased atherogenesis, this raises important issues regarding the benefit of protection against HAV infection vs the risk of developing CAD. This study examines the effect of HAV vaccination on atherosclerosis development in a cholesterol-fed mouse model. Animals either received HAV vaccine, adjuvant, or saline. After 15 weeks, no significant differences were found in lesion area between the groups: HAV vaccine, 13,470 microm2; adjuvant, 16,332 microm2 and saline, 14,356 microm2. Only animals receiving HAV vaccination developed HAV-specific IgG. Thus, in this mouse model, vaccination against HAV does not contribute to the development of atherosclerosis.

Could plasmid-mediated gene transfer into the myocardium be augmented by left ventricular guided laser myocardial injury?

Early studies have indicated no correlation between the amount of mechanical injury and the level of myocardial gene expression following direct plasmid vector injection. Recently, however, evidence suggests that combined laser myocardial injury and plasmid-based gene delivery exert synergistic effects on gene expression and activity. The purpose of the study was to determine whether laser-induced myocardial injury followed by transendocardial gene transfer increases gene expression compared to gene transfer alone. We assessed the ability of a plasmid vector to express its transgene after injection into porcine ischemic myocardium with and without preceding laser myocardial injury. Thirteen animals had transendocardial injections of the luciferase reporter gene in a plamid vector using a catheter-based injection system. Injections (0.5 mg per animal, 50 microg per injection site) were divided into 10 sites in the ischemic territory. Eight animals underwent transendocardial laser injury of the ischemic region (2 Joule per pulse x 10 sites) prior to gene delivery. In five animals, gene injection sites were dispersed between laser channels, and in three animals laser and gene delivery were applied in close proximity (< 5 mm) or at the same location. Luciferase activity was measured at 3 and 7 days. Luciferase expression in ischemic zones was markedly elevated at day 3 and 7, and similar whether animals were pretreated using laser injury followed by gene transfer compared to gene transfer alone. Neither same-spot injection nor dispersed gene delivery were associated with augmented gene expression compared to gene transfer alone. Using the above-described catheter-based approach to combine localized laser injury and injection of naked DNA into ischemic myocardium, laser injury did not augment gene expression above levels present with gene transfer alone.

Serum of cytomegalovirus-infected mice induces monocyte chemoattractant protein-1 expression by endothelial cells.

Inflammation plays a central role in atherogenesis. It was hypothesized that infection of apolipoprotein E-deficient mice with murine cytomegalovirus (MCMV) increases serum levels of proinflammatory cytokines, which may induce "proatherosclerotic" changes in endothelial cells (ECs). Serum samples were collected from uninfected and infected mice. ELISA was used to determine cytokine serum levels and monocyte chemoattractant protein-1 (MCP-1) levels in the supernatant of mouse ECs incubated with serum-containing medium. Serum samples from infected mice induced MCP-1 expression by ECs. These serum samples contain interferon (IFN)-gamma, whereas IFN-gamma was undetectable in serum samples from uninfected mice. Preincubating infected mouse serum with anti-IFN-gamma monoclonal antibody significantly decreased serum-induced EC expression of MCP-1. Thus, MCMV infection increases IFN-gamma serum levels, such serum can induce MCP-1 in ECs, and the serum-induced MCP-1 expression is due, at least in part, to IFN-gamma. If these changes in EC function also occur in vivo in response to infection, they could exacerbate atherogenesis.

Transendocardial delivery of autologous bone marrow enhances collateral perfusion and regional function in pigs with chronic experimental myocardial ischemia.

OBJECTIVES: We tested the hypothesis that intramyocardial injection of autologous bone marrow (ABM) promotes collateral development in ischemic porcine myocardium. We also defined, in vitro, whether bone marrow (BM) cells secrete vascular endothelial growth factor (VEGF) and macrophage chemoattractant protein-1 (MCP-1). BACKGROUND: The natural processes leading to collateral development are extremely complex, requiring multiple growth factors interacting in concert and in sequence. Because optimal angiogenesis may, therefore, require multiple angiogenic factors, we thought that injection of BM, which contains cells that secrete numerous angiogenic factors, might provide optimal therapeutic angiogenesis. METHODS: Bone marrow was cultured four weeks in vitro. Conditioned medium was assayed for VEGF and MCP-1 and was added to cultured pig aortic endothelial cells (PAEC) to assess proliferation. Four weeks after left circumflex ameroid implantation, freshly aspirated ABM (n = 7) or heparinized saline (n = 7) was injected transendocardially into the ischemic zone (0.2 ml/injection at 12 sites). Echocardiography to assess myocardial thickening and microspheres to assess perfusion were performed at rest and during stress. RESULTS: Vascular endothelial growth factor and MCP-1 concentrations increased in a time-related manner. The conditioned medium enhanced, in a dose-related manner, PAEC proliferation. Collateral flow (ischemic/normal zone X 100) improved in ABM-treated pigs (ABM: 98 +/- 14 vs. 83 +/- 12 at rest, p = 0.001; 89 +/- 18 vs. 78 +/- 12 during adenosine, p = 0.025; controls: 92 +/- 10 vs. 89 +/- 9 at rest, p = 0.49; 78 +/- 11 vs. 77 +/- 5 during adenosine, p = 0.75). Similarly, contractility increased in ABM-treated pigs (ABM: 83 +/- 21 vs. 60 +/- 32 at rest, p = 0.04; 91 +/- 44 vs. 36 +/- 43 during pacing, p = 0.056; controls: 69 +/- 48 vs. 64 +/- 46 at rest, p = 0.74; 65 +/- 56 vs. 37 +/- 56 during pacing, p = 0.23). CONCLUSIONS: Bone marrow cells secrete angiogenic factors that induce endothelial cell proliferation and, when injected transendocardially, augment collateral perfusion and myocardial function in ischemic myocardium.