Left atrial rupture secondary to myxomatous mitral valve disease in 11 dogs.

The purpose of this retrospective study was to evaluate the long-term outcome in dogs with left atrial rupture secondary to myxomatous mitral valve disease. Eleven client-owned dogs met the inclusion criteria for the study. Median age was 11.6 yr (range, 8.3-17.8 yr), and median weight was 5.8 kg (range, 3.8-15.2 kg). Of the 11 dogs, 10 survived the initial 24 hr after diagnosis and 5 of the dogs were still alive at the conclusion of data collection. The median survival of all dogs was 203 days. Dogs with no previous history of congestive heart failure (CHF) at the time of diagnosis had a significantly longer median survival time (345 days) compared with dogs with a previous history of CHF (160 days, P = 0.0038). Outcome of dogs with myxomatous mitral valve disease presenting with left atria rupture was more favorable than previously reported, and dogs without previous CHF survived the longest.

Constrictive pericarditis following surgical repair of a peritoneopericardial diaphragmatic hernia in a cat.

A 4-year-old female spayed domestic longhair cat was referred for dyspnea. Further diagnostics revealed severe pleural effusion and a peritoneopericardial diaphragmatic hernia (PPDH). Following surgical correction of the PPDH the pleural effusion persisted. Re-check echocardiogram 4 weeks after initial evaluation revealed leftward deviation of the interventricular septum and interatrial septum occurring with inspiration. There were also exaggerated phasic changes in trans-tricuspid flow velocities suggestive of constrictive pericardial disease. Cardiac catheterization was performed and revealed elevated pressures in the right atrium and right ventricle. Constrictive pericarditis (CP) and epicarditis was confirmed at surgery, where subtotal pericardiectomy was performed with epicardial decortication. The cat continued to develop recurrent pleural effusion after surgery, although the volume and frequency of recurrence slowed over time. This is the first reported case of CP following PPDH repair in a cat.

Pneumatosis coli in a dog.

A 17-year-old, castrated male Maltese was presented with chronic polyphagia and a 2-week history of tenesmus, diarrhea, hematochezia, weight loss, and ribbon-like feces. Pneumatosis coli was diagnosed by abdominal radiography. Concurrent hyperadrenocorticism was suspected. The clinical signs of colorectal disease resolved within 2 days of initiating a lowresidue diet and oral metronidazole. Pneumatosis coli should be considered as a differential diagnosis for colorectal disease in dogs.

Lymphangiosarcoma in two cats.

Lymphangiosarcoma is a malignant neoplasm of the lymphatic endothelium that is rare in cats. This report describes two cases of feline lymphangiosarcoma that originated in the distal limb, causing intractable lymphoedema and serosanguineous discharge with ecchymoses in local and distant sites. In association with the neoplasia, one cat had cortical bone lysis of multiple metacarpal bones of the affected limb and the other had severe immune-mediated haemolytic anaemia (IMHA). The disease in both cases affected young cats and progressed rapidly. Persistent distal limb lymphoedema with serosanguineous discharge is suggestive of lymphangiosarcoma especially when local or distal ecchymoses are evident.

The influence of different temperature programmes on the bioremediation of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated soil by in-vessel composting.

The biodegradation of 16 US. EPA-listed polycyclic aromatic hydrocarbons (sigma PAHs), with accompanying humification and microbial community structure changes during simulated in-vessel composting-bioremediation of an aged coal-tar-contaminated soil amended with green waste were studied over 56 days. The experimental design compared one constant temperature profile (TC=38 degrees C) with three variable temperature profiles (TP1, TP2 and TP3), including treatment at 70 degrees C to comply with regulatory requirements. Greatest sigma PAHs removal (75.4+/-0.1%; k(1)=0.026 day(-1), R(2)=0.98) occurred at TC=38 degrees C compared to all variable temperature profiles TP1 (62.1+/-11.0%; k(1)=0.016 day(-1), R(2)=0.93), TP2 (71.8+/-8.2%; k(1)=0.021 day(-1), R(2)=0.95) and TP3 (45.3+/-9.7%; k(1)=0.010 day(-1), R(2)=0.91). This study proved that using thermophilic temperatures (70 degrees C) towards the end of in-vessel composting processes (TP2) resulted in greater sigma PAHs removal than using other variable temperature profiles (TP1, TP3), as long as the increase was stepwise via an intermediate temperature (55 degrees C). Phospholipid fatty acid (PLFA) signatures indicated that use of thermophilic temperatures towards the end of the in-vessel composting-bioremediation (TP2) resulted in a higher fungal to bacterial PLFA ratio and a lower Gram-positive to Gram-negative (G(+)/G(-)) bacterial ratio. Fluorescence excitation-emission matrix (EEM) showed the presence of peaks typical of humic-like (Ex/Em wavelength pair approximately 340/460 nm) and fulvic-acid-like (Ex/Em wavelength pair approximately 245/460 nm) substances, indicating mineralization and/or maturation of the compost. Varying the temperature during in-vessel composting to comply with regulatory requirements for pathogen control, promoted contaminant biodegradation, microbial activity and compost maturation.

Phenotypic and genotypic characterisation of Bacillus cereus isolates from Bangladeshi rice.

We report the first phenotypic and genotypic characterisation of Bacillus cereus from Bangladeshi rice. Seven strains of B. cereus were isolated from two high-yielding rice varieties (BR5 and BRRI Dhan28) which are cultivated during different rice-growing seasons in Bangladesh. The strains were identified as B. cereus based on colonial and cellular (light microscopic) morphology and were confirmed using the API 50 CHB test system and 16S rDNA analysis. They could also be distinguished from each other based on their substrate-utilisation patterns using the API system. No psychrotrophic (cold-tolerant) isolates were obtained and all were mesophilic with a minimum growth temperature of 10 degrees C, but with an ability to grow at a higher rate than normal temperature (45 degrees C) for B. cereus. All strains had temperature optima between 35 and 45 degrees C, but two groups could be distinguished based on having either a narrow or a broad optimum range. The different strains could not be distinguished based on their phospholipid compositions including major fatty acyl chains which were typical for B. cereus. However, capillary-GC/MS analysis of trace fatty acyl components of the lipids has been used for the first time to group the isolates. Genotypic analysis of the rDNA region has also been used to distinguish the strains. Restriction fragment length polymorphism (RFLP) analysis of the spacer region between the 16S and 23S rRNA genes yielded two groups based on different base sequences, whereas sequence analysis of variable regions in the 16S rRNA gene gave four different groups by base differences at two positions. Despite their association with rice, none of the strains produced emetic toxin. The spore germination response of heat-activated spores of the Bangladeshi B. cereus strains was typical of the bacterium, but three different groups could be identified based on differences in germination rates. The use of this polyphasic approach to taxonomy has enabled all the B. cereus strains to be distinguished from each other.

The Antarctic Psychrobacter sp. TAD1 has two cold-active glutamate dehydrogenases with different cofactor specificities. Characterisation of the NAD+-dependent enzyme.

Psychrobacter sp. TAD1 is a psychrotolerant bacterium from Antarctic frozen continental water that grows from 2 to 25 degrees C with optimal growth rate at 20 degrees C. The new isolate contains two glutamate dehydrogenases (GDH), differing in their cofactor specificities, subunit sizes and arrangements, and thermal properties. NADP+-dependent GDH is a hexamer of 47 kDa subunits and it is comparable to other hexameric GDHs of family-I from bacteria and lower eukaria. The NAD+-dependent enzyme, described in this communication, has a subunit weight of 160 kDa and belongs to the novel class of GDHs with large size subunits. The enzyme is a dimer; this oligomeric arrangement has not been reported previously for GDH. Both enzymes have an apparent optimum temperature for activity of approximately 20 degrees C, but their cold activities and thermal labilities are different. The NAD+-dependent enzyme is more cold active: at 10 C it retains 50% of its maximal activity, compared with 10% for the NADP+-dependent enzyme. The NADP+-dependent enzyme is more heat stable, losing only 10% activity after heating for 30 min, compared with 95% for the NAD+-dependent enzyme. It is concluded that in Psychrobacter sp. TAD1 not only does NAD+-dependent GDH have a novel subunit molecular weight and arrangement, but that its polypeptide chains are folded differently from those of NADP+-dependent GDH, providing different cold-active properties to the two enzymes.

Ether-bond scission in the biodegradation of alcohol ethoxylate nonionic surfactants by Pseudomonas sp. strain SC25A.

Pseudomonas sp. strain SC25A, previously isolated for its ability to grow on alcohol ethoxylates (PEG dodecyl ethers) as sole source of carbon and energy, was shown to be capable of growth on the dodecyl ethers of mono-, di, tri- and octaethylene glycols. Comparative growth yields for this series of alcohol ethoxylate nonionic surfactants indicated that, whereas all of the carbon of monoethylene glycol dodecyl ether (MEGDE) was assimilable, only the alkyl chains were assimilated from the higher ethoxamers. These results are interpreted in terms of a primary biodegradation mechanism in which the scission of the dodecyl-ether bond is the first step. In the case of MEGDE this step separates the dodecyl chain from a C2 fragment, both of which are readily assimilable; for the higher ethoxamers, the assimilable dodecyl chain is accompanied by an ether-containing PEG derivative which would require further rounds of either scission before assimilation. Whole cells and cell extracts converted [1-14C]MEGDE initially and very rapidly to radiolabelled dodecanol. Disappearance of [14C]dodecaol was accompanied by production of [14C]dodecanal. [14C]Dodecanoic acid was present at relatively low concentrations throughout the incubation periods. [14C]Dodecan-1, 12-dioic acid was produced in significant quantities (up to 25% radiolabel), and the onset of its production coincided with the peak concentration of dodecanal, the disappearance of which mirrored the appearance of the dioic acid. Under anaerobic conditions in the presence of cell extracts, dodecanol (55% of radiolabel) and dodecanal (22%) accumulated rapidly from MEGDE, but there was little subsequent conversion to mono- or dicarboxylic acids. These results are interpreted in terms of a pathway initiated by dodecyl-ether cleavage to produce dodecanol, which is subsequently oxidized to dodecanal and dodecanoic acid. The formation of dodecan-1, 12-dioic acid, probably from dodecanal, may represent a means of harbouring carbon under non-growing conditions.