Spectrofluorometric determination of histamine in fish and meat products

A method has been developed for spectrofluorometric determination of histamine in fish and meat products. After a perchloric extract is obtained from samples, histamine is extracted with n-butanol and transferred to hydrochloric acid. Finally, histamine is subjected to a condensation reaction with o-phthalaldehyde (OPT). The method was tested for lack of interference from other amines. Precision of the method in fish products was 6.60% CV; recovery was 96.50%. In meat products, precision was 5.42% CV; recovery was 96.20%. By analysis of variance (P = 0.05), no significant statistical differences were found for recovery values vs histamine content in both foods.     

Blood gas analysis and cooximetry in retired racing Greyhounds

Objective – The purposes of this study were to evaluate the oxygen affinity of hemoglobin (Hb) in healthy retired racing Greyhounds via cooximetry, and to establish reference intervals for blood gases and cooximetry in this breed. Design – Prospective clinical study. Setting – University Teaching Hospital. Animals – Fifty‐seven Greyhounds and 30 non‐Greyhound dogs. Interventions – Venous blood samples were collected from the jugular vein and placed into heparinized tubes. The samples were analyzed within 30 minutes of collection using a blood gas analyzer equipped with a cooximeter. Measurements and Main Results – Greyhounds had significantly higher pH, PO₂, oxygen saturation, oxyhemoglobin, total Hb, oxygen content, and oxygen capacity and significantly lower deoxyhemoglobin and P₅₀ when compared with non‐Greyhound dogs. Conclusion – These findings support the fact that this breed is able to carry a higher concentration of total oxygen in the blood. As reported previously, this breed also has lower P₅₀ and, therefore, high oxygen affinity. In light of recent findings suggesting that in certain tissues a high affinity for oxygen is beneficial, this adaptation may be of benefit during strenuous exercise.     

Successful outcome after a single endoscopic fecal microbiota transplantation in a Shiba dog with non-responsive enteropathy during the treatment with chlorambucil

A 7-year 6-month-old, castrated male Shiba dog presented with a 1-month history of lethargy, anorexia, vomiting, and frequent watery diarrhea. Weight loss, hypoalbuminemia, anemia, and leukocytosis were detected at the first visit. The dog was diagnosed with non-responsive enteropathy (NRE) based on clinical and histopathological examinations. Since the dog did not respond to the immunosuppressive drugs, fecal microbiota transplantation (FMT) was performed during the treatment with chlorambucil. A single endoscopic FMT into the cecum and colon drastically recovered clinical signs and clinicopathological abnormalities and corrected dysbiosis in the dog. No recurrence or adverse events were observed. The present case report suggests that FMT, possibly together with chlorambucil, might be a treatment option for NRE in Shiba dogs that have poorer prognosis compared with other dog breeds.     

Molecular architecture of the "stressosome," a signal integration and transduction hub

A commonly used strategy by microorganisms to survive multiple stresses involves a signal transduction cascade that increases the expression of stress-responsive genes. Stress signals can be integrated by a multiprotein signaling hub that responds to various signals to effect a single outcome. We obtained a medium-resolution cryo-electron microscopy reconstruction of the 1.8-megadalton "stressosome" from Bacillus subtilis. Fitting known crystal structures of components into this reconstruction gave a pseudoatomic structure, which had a virus capsid-like core with sensory extensions. We suggest that the different sensory extensions respond to different signals, whereas the conserved domains in the core integrate the varied signals. The architecture of the stressosome provides the potential for cooperativity, suggesting that the response could be tuned dependent on the magnitude of chemophysical insult.     

Direct visualization of horizontal gene transfer

Conjugation allows bacteria to acquire genes for antibiotic resistance, novel virulence attributes, and alternative metabolic pathways. Using a fluorescent protein fusion, SeqA-YFP, we have visualized this process in real time and in single cells of Escherichia coli. We found that the F pilus mediates DNA transfer at considerable cell-to-cell distances. Integration of transferred DNA by recombination occurred in up to 96% of recipients; in the remaining cells, the transferred DNA was fully degraded by the RecBCD helicase/nuclease. The acquired integrated DNA was tracked through successive replication rounds and was found to occasionally split and segregate with different chromosomes, leading to the inheritance of different gene clusters within the cell lineage. The incidence of DNA splitting corresponds to about one crossover per cell generation.     

Serum Cardiac Troponin I Concentration in Retired Racing Greyhounds

Background: Cardiac troponin I (cTnI) is a polypeptide found specifically in cardiac muscle tissue that has been used as a diagnostic and prognostic indicator of cardiomyopathy. Increases in cTnI are associated with myocardial pathologic processes. However, high serum cTnI concentrations have been observed in normal Greyhounds.
Hypothesis: We hypothesized that Greyhounds have cTnI concentrations higher than non-Greyhound dogs, and that a separate reference range should be established for Greyhounds.
Animals: Blood samples were collected from the jugular vein from a group of 20 healthy Greyhound blood donors.
Methods: Analysis of serum cTnI was performed with an immunoassay system with a detection level of 0.01 ng/mL, as described previously. The Greyhound values were compared with 2 groups of Boxers with and without arrhythmogenic right ventricular cardiomyopathy (ARVC), and to a group of non-Boxer control dogs from a previous study.
Results: The mean cTnI concentration in Greyhounds was significantly higher ( P < .0001) than that in non-Greyhound control dogs, although not significantly different from normal Boxers ( P = .50), or Boxers with ARVC ( P = .58). Greyhound serum cTnI concentrations were in the range found in Boxers with ARVC. The proposed reference range for cTnI in Greyhounds is 0.05–0.16 ng/mL.
Conclusions and Clinical Importance: Greyhounds have a reference range for serum cTnI concentrations that differs from that of other previously published reference ranges for dogs of other breeds. Until a broader database and more precise reference range can be established, caution should be exercised in interpreting serum cTnI concentrations in Greyhounds with suspected cardiac disease.