Unraveling the Interplay of Dopamine, Carbon Monoxide, and Heme Oxygenase in Neuromodulation and Cognition

The dopaminergic system plays important roles in neuromodulation, including prominent roles in complex neurological functions such as cognition, reward, motivation, and memory. Understandably, the highly complex nature of such physiological functions means that their regulation is intertwined with other signaling pathways, as has been demonstrated by numerous studies. Contrary to its public perception of being poisonous at all concentrations, carbon monoxide (CO) is produced endogenously from heme degradation by heme oxygenase (HO) as part of the physiological process of red blood cell turnover. Physiological concentrations of CO can reach high micromolar ranges in the hemoglobin bound form. Low-dose CO has shown therapeutic effects in numerous animal models, including traumatic brain injury via engaging various hemoprotein targets. As such, the HO-CO axis has been shown to offer beneficial effects in organ protection, anti-inflammation, and neuroprotection, among many others. Further, a large number of publications have shown the interactions among CO, HO, and the dopaminergic system. In this review, we critically examine such experimental evidence in a holistic fashion and in the context of a possible dopamine-HO-CO signaling axis. We hope that this Perspective will stimulate additional investigations into the molecular connectivity related to this possible axis and open doors to the development of novel therapeutics that impact the dopaminergic system.

Plight of CORMs: The unreliability of four commercially available CO-releasing molecules, CORM-2, CORM-3, CORM-A1, and CORM-401, in studying CO biology

Carbon monoxide (CO) is an endogenously produced gaseous signaling molecule with demonstrated pharmacological effects. In studying CO biology, three delivery forms have been used: CO gas, CO in solution, and CO donors of various types. Among the CO donors, four carbonyl complexes with either a transition metal ion or borane (BH3) (termed CO-releasing molecules or CORMs) have played the most prominent roles appearing in over 650 publications. These are CORM-2, CORM-3, CORM-A1, and CORM-401. Intriguingly, there have been unique biology findings that were only observed with these CORMs, but not CO gas; yet these properties were often attributed to CO, raising puzzling questions as to why CO source would make such a fundamental difference in terms of CO biology. Recent years have seen a large number of reports of chemical reactivity (e.g., catalase-like activity, reaction with thiol, and reduction of NAD(P)+) and demonstrated CO-independent biological activity for these four CORMs. Further, CORM-A1 releases CO in an idiosyncratic fashion; CO release from CORM-401 is strongly influenced or even dependent on reaction with an oxidant and/or a nucleophile; CORM-2 mostly releases CO2, not CO, after a water-gas shift reaction except in the presence of a strong nucleophile; and CORM-3 does not release CO except in the presence of a strong nucleophile. All these beg the question as to what constitutes an appropriate CO donor for studying CO biology. This review critically summarizes literature findings related to these aspects, with the aim of helping result interpretation when using these CORMs and development of essential criteria for an appropriate donor for studying CO biology.

Reassessing CORM-A1: redox chemistry and idiosyncratic CO-releasing characteristics of the widely used carbon monoxide donor

Redox activity and unreliable carbon monoxide production of CO donor, CORM-A1, presents new complications in its use for studying CO biology.

Light-Activated CO Donor as a Universal CO Surrogate for Pd-Catalyzed and Light-Mediated Carbonylation

A low-molecular-weight, solid CO surrogate that only requires a low-power LED for activation to release 2 equiv of CO is reported. The surrogate can be universally implemented in various palladium-catalyzed carbonylative transformations. It is also compatible with protocols that employ blue-light to activate conventionally inaccessible substrates such as nonactivated alkyl halides. Furthermore, we demonstrate that the photolabile CO-releasing scaffold can be installed into polymeric materials, thereby creating new materials with CO-releasing capabilities.

Evaluation of reference genes for RT-qPCR gene expression analysis in Arabidopsis thaliana exposed to elevated temperatures

Increases in environmental temperature are directly linked to the issue of climate change and are known to significantly disrupt plant growth and development. Studies of gene expression in plants commonly include RT-qPCR but the reliability of the method depends on the use of suitable reference genes for data normalization. Despite this, no reference genes have been validated specifically for experiments in Arabidopsis thaliana employing treatments with elevated temperature. Here, ten genes were selected for expression stability analysis based on the screening of available literature and microarray data from temperature-treated A. thaliana. Expression levels of candidate reference genes were measured in 12-day-old seedlings, rosette leaves and flower buds of 5-week-old A. thaliana plants exposed to five different temperatures (22°C, 27°C, 32°C, 37°C and 42°C) and their expression stabilities were assessed using four statistical algorithms (BestKeeper, geNorm, NormFinder and comparative ΔC_q method). This study provides reliable reference genes for use in A. thaliana RT-qPCR expression analyses employing elevated temperature treatments, namely OGIO and PUX7 in seedlings, UBC21 and PUX7 in leaves, TIP41 and UBC21 in buds, and TIP41 and UBC21 in all three tissues combined. Orthologues of these genes can be of potential use in less studied plants, especially agricultural species heavily affected by climate change.

Scalable Production of Equine Platelet Lysate for Multipotent Mesenchymal Stromal Cell Culture

Translation of multipotent mesenchymal stromal cell (MSC)-based therapies is advancing in human and veterinary medicine. One critical issue is the in vitro culture of MSC before clinical use. Using fetal bovine serum (FBS) as supplement to the basal medium is still the gold standard for cultivation of many cell types including equine MSC. Alternatives are being explored, with substantial success using platelet lysate-supplemented media for human MSC. However, progress lags behind in the veterinary field. The aim of this study was to establish a scalable protocol for equine platelet lysate (ePL) production and to test the ePL in equine MSC culture. Whole blood was harvested into blood collection bags from 20 healthy horses. After checking sample materials for pathogen contamination, samples from 19 animals were included. Platelet concentrates were prepared using a buffy coat method. Platelets, platelet-derived growth factor BB, and transforming growth factor β1 concentrations were increased in the concentrates compared with whole blood or serum (p < 0.05), while white blood cells were reduced (p < 0.05). The concentrates were lysed using freeze/thaw cycles, which eliminated the cells while growth factor concentrations were maintained. Donor age negatively correlated with platelet and growth factor concentrations after processing (p < 0.05). Finally, all lysates were pooled and the ePL was evaluated as culture medium supplement in comparison with FBS, using adipose-derived MSC from four unrelated donor horses. MSC proliferated well in 10% FBS as well as in 10% ePL. However, using 5 or 2.5% ePL entailed highly inconsistent proliferation or loss of proliferation, with significant differences in generation times and confluencies (p < 0.05). MSC expressed the surface antigens CD90, CD44, and CD29, but CD73 and CD105 detection was low in all culture media. Adipogenic and osteogenic differentiation led to similar results in MSC from different culture media. The buffy coat method is useful to produce equine platelet concentrate with increased platelet and reduced white blood cell content in large scales. The ePL obtained supports MSC expansion similar as FBS when used at the same concentration (10%). Further investigations into equine MSC functionality in culture with ePL should follow.

Reticulocytosis in non-anaemic cats and dogs

OBJECTIVE

To evaluate the proportion of blood samples diagnosed with reticulocytosis without anaemia in cats and dogs and report the aetiology and mortality rate of affected animals.

MATERIALS AND METHODS

Retrospective multicentre study including haematological examination of 3956 cats and 11,087 dogs admitted to seven German veterinary clinics (2012 to 2014). The proportion of blood samples with reticulocytosis without anaemia was calculated, and after exclusion of multiple measurements of the same animal, clinical data were evaluated. Animals with reticulocytosis without anaemia were classified as healthy or diseased, and diseased patients were assigned to 12 disease groups. Pretreatment (i.e. non-steroidal anti-inflammatory drugs, glucocorticoids, dipyrone) was recorded.

RESULTS

The proportion of blood samples with reticulocytosis without anaemia was 3·1% (124/3956) in cats and 4·4% (492/11,087) in dogs. Overall, 1·8% (2/111) of cats and 1·5% (7/458) of dogs with reticulocytosis without anaemia were healthy. Blood loss/anaemia, cardiac/respiratory disorders, gastrointestinal disorders and inflammatory disorders as well as cancer were the most frequent underlying diseases. Pretreatment was noted in 39·5% (43/111) of cats and 42·4% (194/458) of dogs. The mortality rate was 37·8% (42/111) in cats and 29·7% (136/458) in dogs with reticulocytosis without anaemia; the median survival time in non-survivors was 1 day (range: 0 to 376 days in cats, 0 to 444 days in dogs).

CLINICAL SIGNIFICANCE

In both species, reticulocytosis without anaemia was observed in a low proportion of blood samples (dogs>cat). Though a bias towards sick animals is possible in our sample, reticulocytosis without anaemia was mainly seen in diseased animals and associated with a mortality rate of approximately one-third of patients.

Evaluation of the Cardiac reader® as a point-of-care instrument for measurement of fibrin D-dimers in dogs

Objective: The aim of this study was the evaluationof the automated point-of-care analyzer Cardiac reader® for quantitative fibrin D-dimer measurement compared to the Liatest™ D-Di™ run on the bench top analyzer STA Compact (all Roche). Material and methods: 41 fresh canine blood specimens submitted from the Clinic for Small Animals, Justus-Liebig-University Giessen were included. Measurement of fibrin D-dimers with the Liatest™ D-Di™ immunoturbidimetric assay was performed in citrated blood plasma stored at –80 °C until analysis. Using the Cardiac reader, D-dimer plasma concentrations were measured with an immunological assay in heparinized fresh (< 1 hour) whole blood specimens. Results: Mean intra-assay coefficient of variation (CV) was 6.13% (range: 2.2–10.0%) for the Liatest™ D-Di and 19.8% (range: 20.1–19.6%) for the Cardiac reader. Fibrin D-dimers detected with the STA Compact exceeded the upper limit of the reference interval (0.4 μg/ml; n = 62 healthy dogs) in 20/41 samples. There was a fair correlation between D-dimer measurements with the Cardiac reader and the comparison method (r = 0.78). Generally, results were underestimated with a mean proportional bias (0.45 μg/ml). The area under the Receiver Operating Characteristic (ROC) curve was 0.895 regarding the detection of increased fibrin D-dimers with the Cardiac reader. At a cut-off value of > 0.2 μg/ml, sensitivity/specificity were 85%/91% and positive/negative likelihood ratios were 8.93/0.17. At a lower cut-off value of 0.15 μg/ml sensitivity and specificity were 90% and 66%, respectively. Conclusion and clinical relevance: The Cardiac reader can be used for quantitative measurement of canine D-dimers, however, due to the odds of false negative results and the high imprecision the comparison method should be preferred.

Bakterienisolate aus dem unteren Respirationstrakt von erkrankten Hunden und deren aktuelle Resistenzsituation

Gegenstand: Retrospektive Untersuchung der mittels bronchoalveolärer Lavage (BAL) gewonnenen Keimflora der tiefen Atemwege erkrankter Hunde auf ihre Antibiotikaempfindlichkeit über 5 Jahre.

Material und Methoden: Auswertung der Ergebnisse der Agardiffusionstests von Bakterienisolaten, die in den Jahren 2004–2009 von 84 Hunden isoliert wurden, und Vergleich mit den Resultaten einer gleichartigen Analyse der Jahre 1999/2000.

Ergebnisse: Bei den 99 geprüften Bakterienisolaten handelte es sich um Pasteurella spp. (27,3%), Bordetella bronchiseptica (20,2%), Staphylococcus spp. (18,2%), Escherichia coli (15,2%), Klebsiella spp. (8,1%), Pseudomonas spp. (7,0%) und Streptococcus spp. (4,0%). Bei acht Hunden lagen Mischkulturen vor. Die Mehrzahl der Bordetella-(B.-)bronchiseptica-Isolate erwies sich als sensibel gegenüber den Fluorchinolonen sowie Tetracyclin, Doxycyclin und Polymyxin B. Im Vergleich zu 1999/2000 zeigte sich ein höherer Anteil der gegenüber Amoxicillin/Clavulansäure und Chloramphenicol empfindlichen B.-bronchiseptica-Isolate, wobei die Zunahme bezüglich Chloramphenicol statistisch signifikant war. Die überwiegende Anzahl der Staphylococcus-Isolate erwies sich gegenüber Enrofloxacin, Marbofloxacin, Amoxicillin/Clavulansäure, Chloramphenicol, Cephalexin, Doxycyclin und Polymyxin B sensibel. Im Vergleich zu 1999/2000 ergab sich ein erhöhter Anteil an Chloramphenicolund Tetracyclin-sensiblen Staphylococcus-Isolaten. Der Anteil Enrofloxacin-sensibler KlebsiellenIsolate betrug 62,5%, während er 1999/2000 bei 100% lag. Eine Sensibilität aller getesteten Klebsiellen-Isolate ließ sich noch gegenüber Polymyxin B nachweisen. Kein Antibiotikum zeigte eine Wirksamkeit gegenüber allen E.-coli-Isolaten. Statistisch signifikant war die Abnahme der gegenüber Amoxicillin/Clavulansäure-sensiblen Isolate.

Schlussfolgerung und klinische Relevanz: Die Studie unterstreicht den Nutzen der BAL für eine ätiologische Diagnostik und den anschließenden fundierten Einsatz von Antibiotika. Die Mehrzahl der Bakterienisolate erwies sich als empfindlich gegenüber den Fluorchinolonen.

Myeloperoxidase deficiency in dogs observed with the ADVIA®120

Objective: In contrast to humans, neutrophil myeloperoxidase deficiency (MPOD) has been rarely investigated in dogs. The hematology analyzer ADVIA®120 differentiates leukocytes based on the cellular volume and their myeloperoxidase concentration. The aim of this study was the characterization of myeloperoxidase deficiency in dogs and the evaluation of the diagnostic use of the ADVIA®120 Myeloperoxidase Index (MPXI). Material and methods: ADVIA® peroxidase scatter plots indicative of MPOD were reviewed. Severity of MPOD was classified semiquantitatively in three groups (MPOD grade 1–3): MPOD grade 1 (MPOD-1): neutrophils showing an abnormal shift of the population, < 25% extending in the monocyte cluster and therefore misclassified, MPOD-2: ~25–50% of neutrophils misclassified, MPOD-3: 50–100% of the neutrophils misclassified due to their location in the monocyte cluster. Sex, age, and breed of the dogs as well as diagnosis, and MPXI were recorded. Results: 29 dogs (nine females and 20 males belonging to 23 breeds) with 38 analyses consistent with MPOD were found. Diseases were characterized by severe leukocyte consumption and included mainly parvovirosis (8/29), DIC/sepsis (3/29), pyometra, pyothorax, pneumonia, pancreatic abscess, and cystitis. A significantly lower mean MPXI in MPOD-3 was present in comparison to the mean MPXI of MPOD-1 (p < 0.05), however, there was a great overlap between the groups. Conclusion: Diseases associated with neutrophil consumption may show an acquired MPOD in dogs. High standard deviation limits the diagnostic use of the MPXI for detection of MPOD. Clinical relevance: The ADVIA®120 cytograms are a good screening tool for detection of MPOD in dogs, but the use of the MPXI is impaired in this species.

Koagulopathien bei Hund und Katze

Der Gerinnungsprozess findet in drei Phasen statt, der primären und sekundären (plasmatischen) Hämostase sowie der Gerinnungsinhibition/Fibrinolyse. Nach der neueren Definition von Koagulopathien werden diese in „Minus-Koagulopathien“ (= verminderte sekundäre Hämostase) und „Plus-Koagulopathien“ (= Thrombophilie, d. h. Thromboseneigung) unterteilt. Minus-Koagulopathien können angeboren oder erworben sein. Die wichtigsten angeborenen Koagulopathien beim Hund umfassen Faktor-VIIIund FaktorIX-Mangel (Hämophilie A/B). Bei Katzen ist ein Faktor-XII-Mangel bekannt, der jedoch nicht mit ausgeprägten klinischen Symptomen einhergeht. Die häufigste erworbene Minus-Koagulopathie ist die disseminierte intravasale Gerinnung (DIC), gefolgt von Kumarinvergiftung, hochgradigem Leberversagen oder einer Heparintherapie. Die Ätiologie von Plus-Koagulopathien umfasst renalen Proteinverlust, Neoplasien, immunvermittelte Anämie und Vaskulitis. Patienten mit Minus-Koagulopathien zeigen klinisch Hämatome, Epistaxis und Blutungen in Körperhöhlen. Dagegen sind Erkrankungen der primären Hämostase durch Petechien/Ekchymosen charakterisiert. Die Symptome von Störungen der Gerinnungsinhibition sind vielfältig und von der Lokalisation der Thrombusbildung abhängig. Die Patienten können Lahmheit (bei Aortenthrombose) oder Dyspnoe im Fall einer Lungenembolie zeigen. Die wichtigsten diagnostischen Tests bei Patienten mit Blutungsneigung sind die Bestimmung der Thrombozytenzahl sowie eine Messung der Thromboplastinzeit (PT) und aktivierten partiellen Thromboplastinzeit (aPTT). Bei Hunden mit Verdacht auf DIC sollten zusätzlich D-Dimere und Fibrinogen bestimmt werden. Ein erhöhter D-Dimer-Wert ist Anzeichen einer Lyse quervernetzter Fibringerinnsel und kann auch bei Hunden mit Thromboembolien, vorangegangenen chirurgischen Eingriffen oder Blutungen in Körperhöhlen auftreten. Die Therapie von Koagulopathien ist variabel und abhängig von der Ätiologie der Erkrankung.

Hemostatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus

OBJECTIVE

Prospective characterization of hemostastatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus (GDV).

MATERIAL AND METHODS

Coagulation variables (platelets, prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen, antithrombin [AT], protein C [PC], protein S [PS], D-dimers), plasma lactate concentration and inflammatory biomarkers (C-reactive protein, white blood cell [WBC] count, lymphocyte and neutrophil numbers) were assessed in 20 dogs with GDV presented between 2011 and 2012. Blood was taken preoperatively and at days 1 and 3 postoperatively. The prognostic value of these variables before and after surgery was evaluated as well as the behavior of variables during the study.

RESULTS

Overall, 7/20 (35%) dogs did not survive; two dogs (29%) were euthanized during surgery due to severe gastric necrosis and 5 (71%) dogs after surgery due to sepsis and disseminated intravascular coagulopathy. Prior to surgery, median plasma lactate concentration was significantly (p = 0.01) lower in survivors (6.2 mmol/l, range 1.9-9.7 mmol/l) when compared to non-survivors (11.8 mmol/l, range 7.5-16.2 mmol/l). In dogs dying after surgery, significantly higher plasma lactate concentration, coagulation times and D-dimer concentration were present as well as lower fibrinogen concentration and activity of PC and AT compared to survivors. At discharge, activity of AT, PC and PS were markedly below the reference interval in 6/13 (46%), 11/13 (85%), and 8/13 (62%) dogs, respectively.

CLINICAL RELEVANCE

Only lactate plasma concentration was of preoperative prognostic value. After surgery, severe abnormalities of coagulation variables, especially the endogenous anticoagulants were present in most of the dogs. The severity of the abnormalities was associated with survival.

[Extreme neutrophilia in cats - aetiology and prognosis]

OBJECTIVE

The aim of this retrospective study was to evaluate the aetiology and prognostic factors of extreme neutrophilia in cats.

MATERIAL AND METHODS

Patient data over a 5-year period (January 2008  -  December 2013) were reviewed. Cats with a neutrophil count > 40 x 10⁹/l were included. They were further assigned to four groups: "inflammation", "neoplasia", "immune-mediated diseases", "unknown aetiology". Clinical signs, rectal temperature, hospitalisation, duration of hospitalisation, survival, left-shift and toxicity of neutrophils were evaluated.

RESULTS

In total, 28/5185 cats (0.5%) displayed extreme neutrophilia with a mean neutrophil count of 48.5 x 10⁹/l (40.0-76.0 x 10⁹/l). The most common aetiology was a severe inflammation, as seen in 16/28 cats (57%), whereby peritonitis (5/15 cats, 31%) predominated. In cats with neoplastic diseases (9/28 cats, 32%), intestinal neoplasia with subsequent peritonitis was the most common diagnosis (4/9 cats, 44%). Diseases of unknown aetiology (2/28 cats, 7%) and immune-mediated diseases (1/28, 3.6%) were rare. The most common clinical indications included lethargy, anorexia, fever, and gastrointestinal signs. Rectal temperature ranged between 33.9  °C and 40.2   °C, whereby in 2/24 cats (8%) hyperthermia (> 39.3°C) and in 5/24 cats (21%) hypothermia (< 38.0°C) was observed. Hospitalisation occurred in 21/28 cats (75%) with a median duration of 5.5 days (1-30 days). In 24/28 cats, a manual differential count was performed. A left-shift and toxicity of neutrophils were seen in 23/24 cats (96%) and 21/24 cats (88%), respectively. The overall median survival rate was 50%, whereby the survival rate was significantly lower in cats with neoplasia than in those with inflammatory diseases (22% vs. 56%, p < 0.0001).

CLINICAL RELEVANCE

An extreme neutrophilia is rare. It is commonly caused by peritonitis due to foreign bodies or ruptured intestinal tumours (in particular, intestinal lymphomas) and is characterised by a high mortality.

Complexation of Cm(iii) with the recombinant N-lobe of human serum transferrin studied by time-resolved laser fluorescence spectroscopy (TRLFS)

The complexation of Cm(iii) with the recombinant N-lobe of human serum transferrin hTf/2N is investigated using TRLFS. The results reveal significant differences in the complexation properties of transferrin and the half molecule.

A retrospective study of 1,098 blood samples with anemia from adult cats: frequency, classification, and association with serum creatinine concentration

BACKGROUND

Frequency and classification of anemia in terms of regeneration status and erythrocyte indices are not well described in cats.

OBJECTIVE

To determine frequency and regenerative status of anemia in samples from adult cats, to assess the sensitivity and specificity of macrocytosis and hypochromasia for detecting regenerative anemia (RA), and to evaluate the association of anemia with increased serum creatinine concentration (SC).

STUDY POPULATION

Laboratory records from 30,503 blood samples from cats (2003-2011).

METHODS

Clinicopathologic data reviewed retrospectively. Anemia defined as hematocrit (Ht) ≤27%, red blood cell count (RBC) ≤5.5 × 10(6)/μL and hemoglobin (Hb) ≤9.0 g/dL. RA defined by manual absolute reticulocyte count >50 × 10(3)/μL. Macrocytosis was defined as mean corpuscular volume (MCV) >55 fL and hypochromasia as mean corpuscular hemoglobin concentration (MCHC) <31 g/dL. Cutoff for increased serum creatinine concentration was 1.6 mg/dL.

RESULTS

Overall, 1,098 of 30,503 blood samples (3.6%) from cats fulfilled criteria for anemia, 633 of 1,098 (57.7%) classified as nonregenerative (NRA) and 465 of 1,098 (42.3%) as regenerative. RBC, Ht, and Hb were significantly lower in the RA compared to NRA group (P < .05). Sensitivity and specificity of the combined high MCV and low MCHC to detect samples with RA were 19.5 and 90.7%. SC was increased in 572 of the 1,098 anemic samples (52.1%) and in 11,121 of 29,405 of nonanemic samples (37.8%).

CONCLUSIONS AND CLINICAL IMPORTANCE

Majority of anemic samples were classified as NRA. Anemia was more severe in cats with RA. Erythrocyte indices were not sensitive indicators of RA.

[Radio-induced breast morphoea: an unrecognized complication]

Morphoea is a localized scleroderma. Since the 1990s, it is described as a complication after irradiation for breast cancer. This complication is unrecognized and underdiagnosed. Irradiation seems to be a factor inducing an autoimmune process. Clinicians should be aware in case of an erythema in a treated area, appearing on average one year after the end of the irradiation. Histology alone can prove the diagnosis and rule out differential diagnoses: principally mastitis (carcinomatous, infectious), chronic radiodermatitis or radiation recall. Treatment of this rare complication is not consensual; it is most often topical steroids. The evolution is marked by a gradual decrease from the initial inflammation. Sclerosis persists, more or less substantially.

Thermal inactivation of a single strain each of serotype O26:H11, O45:H2, O103:H2, O104:H4, O111:H⁻, O121:H19, O145:NM, and O157:H7 cells of Shiga toxin-producing Escherichia coli in wafers of ground beef

For each of two trials, freshly ground beef of variable fat content (higher: 70:30 %lean:%fat; lower: 93:7 %lean:%fat) was separately inoculated with ca. 7.0 log CFU/g of a single strain of Escherichia coli serotypes O26:H11, O45:H2, O103:H2, O104:H4, O111:H⁻, O121:H19, O145:NM, and O157:H7. Next, ca. 3-g samples of inoculated beef were transferred into sterile filter bags and then flattened (ca. 1.0 mm thick) and vacuum sealed. For each temperature and sampling time, three bags of the inoculated wafers of beef were submerged in a thermostatically controlled water bath and heated to an internal temperature of 54.4°C (130°F) for up to 90 min, to 60°C (140°F) for up to 4 min, or to 65.6°C (150°F) for up to 0.26 min. In lower fat wafers, D-values ranged from 13.5 to 23.6 min, 0.6 to 1.2 min, and 0.05 to 0.08 min at 54.4, 60.0, and 65.6°C, respectively. Heating higher fat wafers to 54.4, 60.0, and 65.6°C generated D-values of 18.7 to 32.6, 0.7 to 1.1, and 0.05 to 0.2 min, respectively. In addition, we observed reductions of ca. 0.7 to 6.7 log CFU/g at 54.4°C after 90 min, ca. 1.1 to 6.1 log CFU/g at 60.0°C after 4 min, and 0.8 to 5.8 log CFU/g at 65.6°C after 0.26 min. Thus, cooking times and temperatures effective for inactivating a serotype O157:H7 strain of E. coli in ground beef were equally effective against the seven non-O157:H7 Shiga toxin-producing strains investigated herein.

[Bacterial susceptibility testings of the lower airways of diseased dogs]

OBJECTIVE

In this retrospective study over 5 years the bacterial flora of the deep airways of diseased dogs was sampled using bronchioalveolar lavage and its in-vitro susceptibility to numerous antimicrobial agents was analysed.

MATERIAL AND METHODS

Susceptibility testing of bacterial isolates from 84 dogs performed from 2004 to 2009 were evaluated and compared to data collected in 1999/2000.

RESULTS

The 99 bacterial isolates comprised Pasteurella spp. (27.3%), Bordetella bronchiseptica (20.2%), Staphylococcus spp. (18.2%), Escherichia coli (15.2%), Klebsiella spp. (8.1%), Pseudomonas spp. (7.0%), and Streptococcus spp. (4.0%). Lavage samples of eight dogs revealed simultaneous occurrence of more than one species. The majority of the tested Bordetella bronchiseptica-isolates were susceptible to fluoroquinolones as well as tetracycline, doxycycline and polymyxin B. The number of amoxicillin/clavulanic acid- and chloramphenicol-resistant isolates decreased compared to 1999/2000. The increase of chloramphenicol-susceptible isolates was statistically significant. The tested Staphylococcus-isolates revealed a susceptibility to fluoroquinolones, amoxicillin, cephalexin, doxycycline, and polymyxin B. Compared to the earlier study, a major portion exhibited susceptibility to chloramphenicol and tetracycline. None of the Klebsiella spp. tested in 1999/2000 was resistant to enrofloxacin, whereas only 62.5% of the isolates examined during 2004-2009 were susceptible. A susceptibility of all tested Klebsiella -isolates was detectable with respect to polymyxin B. Regarding E.coli , none of the tested antibiotics revealed an in-vitro activity against all of the tested isolates. The increase of amoxicillin/clavulanic acid-resistant isolates was statistically significant.

CONCLUSION AND CLINICAL RELEVANCE

The study demonstrates the benefits of bronchioalveolar lavage as a diagnostic tool to ensure a responsible utilisation of antibiotics. Most of the tested bacterial isolates were susceptible to fluoroquinolones.

[Stereotactic radiotherapy of intracranial benign tumors]

Stereotactic radiotherapy can be delivered in one fraction or in multiple fractions schedule. It is used in benign tumours such as meningiomas, mainly localized in the base of the skull, for acoustic schwannoma and pituitary tumours. Whatever the tumour, results with the Gamma Knife(®) are the most numerous, but those obtained by linear accelerators, adapted or dedicated, are comparable. The peripheral dose is preferred to the dose delivered to the isocentre. One fraction stereotactic irradiation should be proposed in small lesions and fractionated treatment for tumours larger. Whatever the tumour, the results are satisfactory with a control rate of 90%. However, this value reflects a disparity assessment, radiological stability for meningiomas, radiological stability and preservation of useful hearing in schwannoma and radiological stability and a decrease in hormonal secretions for pituitary adenomas. Overall complication rates are low. In total, the treatment of benign lesions with stereotactic irradiation gives satisfactory results with few complications.

Haematopoietic stem cell differentiation promotes the release of prominin-1/CD133-containing membrane vesicles--a role of the endocytic-exocytic pathway

The differentiation of stem cells is a fundamental process in cell biology and understanding its mechanism might open a new avenue for therapeutic strategies. Using an ex vivo co-culture system consisting of human primary haematopoietic stem and progenitor cells growing on multipotent mesenchymal stromal cells as a feeder cell layer, we describe here the exosome-mediated release of small membrane vesicles containing the stem and cancer stem cell marker prominin-1 (CD133) during haematopoietic cell differentiation. Surprisingly, this contrasts with the budding mechanism underlying the release of this cholesterol-binding protein from plasma membrane protrusions of neural progenitors. Nevertheless, in both progenitor cell types, protein–lipid assemblies might be the essential structural determinant in the release process of prominin-1. Collectively, these data support the concept that prominin-1-containing lipid rafts may host key determinants necessary to maintain stem cell properties and their quantitative reduction or loss may result in cellular differentiation.

Evaluation of bacterial diversity in the rumen and feces of cattle fed different levels of dried distillers grains plus solubles using bacterial tag-encoded FLX amplicon pyrosequencing

Dietary components and changes cause shifts in the gastrointestinal microbial ecology that can play a role in animal health and productivity. However, most information about the microbial populations in the gut of livestock species has not been quantitative. In the present study, we utilized a new molecular method, bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP) that can perform diversity analyses of gastrointestinal bacterial populations. In the present study, cattle (n = 6) were fed a basal feedlot diet and were subsequently randomly assigned to 1 of 3 diets (n = 2 cows per diet). In each diet, 0, 25, or 50% of the concentrate portion of the ration was replaced with dried distillers grain (DDGS). Ruminal and fecal bacterial populations were different when animals were fed DDGS compared with controls; ruminal and fecal Firmicute:Bacteroidetes ratios were smaller (P = 0.07) in the 25 and 50% DDG diets compared with controls. Ruminal pH was decreased (P < 0.05) in ruminal fluid from cattle fed diets containing 50% compared with 0% DDGS. Using bTEFAP, the normal microbiota of cattle were examined using modern molecular methods to understand how diets affect gastrointestinal ecology and the gastrointestinal contribution of the microbiome to animal health and production.

Myeloperoxidase deficiency in dogs observed with the ADVIA®120. A retrospective study

OBJECTIVE

In contrast to humans, neutrophil myeloperoxidase deficiency (MPOD) has been rarely investigated in dogs. The hematology analyzer ADVIA®120 differentiates leukocytes based on the cellular volume and their myeloperoxidase concentration. The aim of this study was the characterization of myeloperoxidase deficiency in dogs and the evaluation of the diagnostic use of the ADVIA®120 Myeloperoxidase Index (MPXI).

MATERIAL AND METHODS

ADVIA® peroxidase scatter plots indicative of MPOD were reviewed. Severity of MPOD was classified semiquantitatively in three groups (MPOD grade1-3): MPOD grade1 (MPOD-1): neutrophils showing an abnormal shift of the population, <25% extending in the monocyte cluster and therefore misclassified, MPOD-2: ~25-50% of neutrophils misclassified, MPOD-3: 50-100% of the neutrophils misclassified due to their location in the monocyte cluster. Sex, age, and breed of the dogs as well as diagnosis, and MPXI were recorded.

RESULTS

29 dogs (nine females and 20 males belonging to 23 breeds) with 38 analyses consistent with MPOD were found. Diseases were characterized by severe leukocyte consumption and included mainly parvovirosis (8/29), DIC/sepsis (3/29), pyometra, pyothorax, pneumonia, pancreatic abscess, and cystitis. A significantly lower mean MPXI in MPOD-3 was present in comparison to the mean MPXI of MPOD-1 (p<0.05), however, there was a great overlap between the groups.

CONCLUSION

Diseases associated with neutrophil consumption may show an acquired MPOD in dogs. High standard deviation limits the diagnostic use of the MPXI for detection of MPOD.

CLINICAL RELEVANCE

The ADVIA®120 cytograms are a good screening tool for detection of MPOD in dogs, but the use of the MPXI is impaired in this species.

Population structure and historical biogeography of European Arabidopsis lyrata

Understanding the natural history of model organisms is important for the effective use of their genomic resources. Arabidopsis lyrata has emerged as a useful plant for studying ecological and evolutionary genetics, based on its extensive natural variation, sequenced genome and close relationship to A. thaliana. We studied genetic diversity across the entire range of European Arabidopsis lyrata ssp. petraea, in order to explore how population history has influenced population structure. We sampled multiple populations from each region, using nuclear and chloroplast genome markers, and combined population genetic and phylogeographic approaches. Within-population diversity is substantial for nuclear allozyme markers (mean P=0.610, A(e)=1.580, H(e)=0.277) and significantly partitioned among populations (F(ST)=0.271). The Northern populations have modestly increased inbreeding (F(IS)=0.163 verses F(IS)=0.093), but retain comparable diversity to central European populations. Bottlenecks are common among central and northern Europe populations, indicating recent demographic history as a dominant factor in structuring the European diversity. Although the genetic structure was detected at all geographic scales, two clear differentiated units covering northern and central European areas (F(CT) =0.155) were identified by Bayesian analysis and supported by regional pairwise F(CT) calculations. A highly similar geographic pattern was observed from the distribution of chloroplast haplotypes, with the dominant northern haplotypes absent from central Europe. We conclude A. l. petraea's cold-tolerance and preference for disturbed habitats enabled glacial survival between the alpine and Nordic glaciers in central Europe and an additional cryptic refugium. While German populations are probable peri-glacial leftovers, Eastern Austrian populations have diversity patterns possibly compatible with longer-term survival.

New insights into the cell biology of hematopoietic progenitors by studying prominin-1 (CD133)

Prominin-1 (alias CD133) has received considerable interest because of its expression by several stem and progenitor cells originating from various sources, including the neural and hematopoietic systems. As a cell surface marker, prominin-1 is now used for somatic stem cell isolation. Its expression in cancer stem cells has broadened its clinical value, as it might be useful to outline new prospects for more effective cancer therapies by targeting tumor-initiating cells. Cell biological studies of this molecule have demonstrated that it is specifically concentrated in various membrane structures that protrude from the planar areas of the plasmalemma. Prominin-1 binds to the plasma membrane cholesterol and is associated with a particular membrane microdomain in a cholesterol-dependent manner. Although its physiological function is not yet determined, it is becoming clear that this cell surface protein, as a unique marker of both plasma membrane protrusions and membrane microdomains, might reveal new aspects of the cell biology of rare stem and cancer stem cells. The aim of this review is to outline the recent discoveries regarding the dynamic reorganization of the plasma membrane of rare CD133+ hematopoietic progenitor cells during cell migration and division.

Curcumin inhibits constitutive STAT3 phosphorylation in human pancreatic cancer cell lines and down-regulates survivin/BIRC5 gene expression

15030

The anti-apoptotic gene survivin/BIRC5 plays an important role in cellular proliferation and survival of cancer cells. Regulated by constitutively activated STAT3, Survivin/BIRC5 may be a target for inhibiting cellular proliferation in pancreatic cancer cell lines. The purpose of this study was (a) to determine the effect of curcumin (diferuloylmethane) on survivin/BIRC5 expression and (b) a possible role of STAT3 activation in Survivin/BIRC5 expression in pancreatic cancer cell lines. We have incubated four pancreatic cancer cell lines with different amounts of curcumin. The expression of Survivin/BIRC5 on mRNA and protein level was measured with RT-PCR and western blot analysis. The activation of STAT3 through phosphorylation, contributing to the regulation of survivin was analyzed with western blot analysis. The incubation of the pancreatic cancer cell lines with curcumin resulted in a down-regulation of cellular proliferation in all cell lines tested but with different rates of inhibition. The expression of survivin/BIRC5 on mRNA and protein level was significantly down-regulated after treatment with 30 μM. Curcumin blocked the phosphorylation of STAT3 in a concentration-dependent manner. Treatment of pancreatic cancer cell lines with curcumin resulted in an induction of apoptosis as measured with FacScan analysis. We conclude that curcumin inhibits several key factors in cancer cellular pathways and may have the potential to be investigated in pancreatic cancer.

No significant financial relationships to disclose.

Treatment with rAD001 improves the efficacy of siRNA mediated down-regulation of survivin/BIRC5 in pancreatic carcinoma cell lines

15146

The rapamycin derived mTOR inhibitor RAD001 (everolimus) is cytotoxic to a number of cell lines. Because survivin, an important mediator of apoptosis and cell survival, is one of the targets down-regulated by RAD001, we tested the ability of a combination of RAD001 and siRNA mediated inhibition of survivin to enhance the cytotoxic effects. We have used four pancreatic cancer cell lines, MiaPaCa-2, BxPC-3, AsPC-1 and Panc-1. We found that the cytotoxic effect was enhanced in all cell lines after treatment with RAD001 and survivin siRNA. An efficient way of treatment was the initial down-regulation of survivin with RAD001 and a subsequent incubation with survivin siRNA. We conclude, that the transformation efficiency of siRNA, still a limiting factor in using this method, is more sufficiently combining both ways to down-regulate survivin. Our data indicate that a combination of mTOR inhibitors like RAD001 and survivin-targeted down-regulation with siRNA may improve the efficacy of therapy in pancreatic cancer.

No significant financial relationships to disclose.

Polarization of human hematopoietic progenitors during contact with multipotent mesenchymal stromal cells: effects on proliferation and clonogenicity

Establishment of a defined cell culture system that facilitates ex vivo expansion of isolated hematopoietic stem and progenitor cells (HSPCs) is a crucial issue in hematology and stem cell transplantation. Here we have evaluated the capacity of primary human multipotent mesenchymal stromal cells (MSCs) to support the ex vivo expansion of peripheral CD34(+)-enriched HSPCs. We observed that HSPCs co-cultured on MSCs showed a substantially higher total expansion rate compared to those growing without. Moreover, in addition to the expansion of CD34(+)CD133(+) and CD34(+)CD133(-) cells, a third population of CD133(+)CD34(-) stem cells became detectable after expansion. Direct contact between HSPCs and the feeder layer appears beneficial for the expansion of HSPCs harboring CD133(+) phenotype, i.e., CD34(+)CD133(+) and CD133(+)CD34(-), in contrast to CD34(+)CD133(-) cells. Interestingly, electron microscopy and immunofluorescence analyses revealed that adherent HSPCs display various morphologies; they are either round with, in some cases, the appearance of a microvillar pole or exhibit several distinct types of plasma membrane protrusions such as lamellipodium and magnupodium. CD133 is selectively concentrated therein, whereas CD34 is randomly distributed over the entire surface of HSPCs. Together, this co-culture offers a unique experimental system to further characterize the biology and role of markers of rare stem cell populations.