Optical detection of DNA conformational polymorphism on single-walled carbon nanotubes

The transition of DNA secondary structure from an analogous B to Z conformation modulates the dielectric environment of the single-walled carbon nanotube (SWNT) around which it is adsorbed. The SWNT band-gap fluorescence undergoes a red shift when an encapsulating 30-nucleotide oligomer is exposed to counter ions that screen the charged backbone. The transition is thermodynamically identical for DNA on and off the nanotube, except that the propagation length of the former is shorter by five-sixths. The magnitude of the energy shift is described by using an effective medium model and the DNA geometry on the nanotube sidewall. We demonstrate the detection of the B-Z change in whole blood, tissue, and from within living mammalian cells.     

Impact of different stages of juice processing on the anthocyanin, flavonol, and procyanidin contents of cranberries

Juice is the most common form in which cranberries are consumed; however there is limited information on the changes of polyphenolic content of the berries during juice processing. This study investigated the effects of three different pretreatments (grinding plus blanching; only grinding; only blanching) for cranberry juice processing on the concentrations of anthocyanins, flavonols, and procyanidins throughout processing. Flavonols and procyanidins were retained in the juice to a greater extent than anthocyanins, and pressing resulted in the most significant losses in polyphenolics due to removal of the seeds and skins. Flavonol aglycones were formed during processing as a result of heat treatment. Drying of cranberry pomace resulted in increased extraction of flavonols and procyanidin oligomers but lower extraction of polymeric procyanidins. The results indicate that cranberry polyphenolics are relatively stable during processing compared to other berries; however, more work is needed to determine their fate during storage of juices.     

Aerobic bacteria from mucous membranes, ear canals, and skin wounds of feral cats in Grenada, and the antimicrobial drug susceptibility of major isolates

In a 2-year period 54 feral cats were captured in Grenada, West Indies, and a total of 383 samples consisting of swabs from rectum, vagina, ears, eyes, mouth, nose and wounds/abscesses, were cultured for aerobic bacteria and campylobacters. A total of 251 bacterial isolates were obtained, of which 205 were identified to species level and 46 to genus level. A commercial bacterial identification system (API/Biomerieux), was used for this purpose. The most common species was Escherichia coli (N = 60), followed by Staphylococcus felis/simulans (40), S. hominis (16), S. haemolyticus (12), Streptococcus canis (9), Proteus mirabilis (8), Pasteurella multocida (7), Streptococcus mitis (7), Staphylococcus xylosus (7), S. capitis (6), S. chromogenes (4), S. sciuri (3), S. auricularis (2), S. lentus (2), S. hyicus (2), Streptococcus suis (2) and Pseudomonas argentinensis (2). Sixteen other isolates were identified to species level. A molecular method using 16S rRNA sequencing was used to confirm/identify 22 isolates. Salmonella or campylobacters were not isolated from rectal swabs. E. coli and S. felis/simulans together constituted 50% of isolates from vagina. S. felis/simulans was the most common species from culture positive ear and eye samples. P. multocida was isolated from 15% of mouth samples. Coagulase-negative staphylococci were the most common isolates from nose and wound swabs. Staphylococcus aureus, or S. intemedius/S. pseudintermedius were not isolated from any sample. Antimicrobial drug resistance was minimal, most isolates being susceptible to all drugs tested against, including tetracycline.     

Unilateral invasive intraocular melanoma with choroidal and optic nerve involvement resulting in bilateral vision loss in a Labrador Retriever

A 10-year-old male castrated Labrador Retriever cross was referred for evaluation of acute vision loss. Ophthalmic examination revealed mild left sided exophthalmos, bilateral resting mydriasis, an absent direct and reduced consensual PLR in the left eye and reduced direct and absent consensual PLR in the right eye. Examination of the cornea and anterior segment with slit lamp biomicroscopy was unremarkable. Indirect fundoscopy revealed a left optic nerve head obscured by a darkly pigmented lesion. Fundic examination in the right eye was unremarkable. Magnetic resonance imaging revealed a smoothly marginated, lobulated cone to irregularly shaped, strongly T1 hyperintense, T2 and T2 fluid-attenuated inversion recovery hypointense, strongly contrast enhancing mass closely associated with the entire left optic nerve, extending across the optic chiasm and into the right optic nerve ventrally. Full clinical staging revealed no evidence of metastasis. Exenteration of the left eye was performed. Histopathology revealed an unencapsulated, poorly demarcated, multilobulated and infiltrative pigmented mass that was effacing the posterior choroid and optic nerve. The mass was composed of a moderately pleomorphic population of heavily pigmented polygonal cells arranged in sheets and clusters, displaying moderate anisocytosis and anisokaryosis. The population of cells contained moderate amounts of abundant brown-black granular pigment consistent with melanin within the cytoplasm. Mitotic figures averaged approximately three per ten 400× fields (2.37 mm²). This is the first report of a melanocytic tumor invading along the optic nerve and tract to result in contralateral vision loss.     

Refractory shock,hypercoagulability, and multiorgan thrombosis associated with hypertrophic osteodystrophy in a dog

Objective

To describe the clinical findings and case progression in a dog presenting with severe systemic inflammatory response, refractory shock, progressive metabolic acidosis, and respiratory failure that was ultimately diagnosed with hypertrophic osteodystrophy (HOD).

Case Summary

A 4-month-old male intact Mastiff presented with a 24-hour history of lethargy and generalized ostealgia. On examination, the dog was recumbent, febrile, and tachycardic with pain on palpation of the abdomen, right femur, and mandible. Appendicular joint radiographs showed changes consistent with osteochondrosis and ulnar-retained cartilaginous cores, with no overt evidence of HOD. Initial treatment included IV fluid therapy, multimodal analgesia, and broad-spectrum antimicrobials. Vasopressor therapy was initiated following hemodynamic decompensation. Synovial fluid cytological analysis and culture revealed nonseptic suppurative inflammation and no bacterial growth, respectively. Blood and urine cultures also yielded no growth. Viscoelastic testing was consistent with hypercoagulability. The dog initially had a metabolic acidosis with appropriate respiratory compensation that progressed to a mixed metabolic and respiratory acidosis despite aggressive therapies that included antimicrobials, vasopressors, positive inotropes, and corticosteroids. Humane euthanasia was elected approximately 32 hours after admission. Necropsy yielded a diagnosis of HOD.

New or Unique Information Provided

This is the first report detailing the occurrence of refractory shock and hypercoagulability associated with HOD in a dog without evidence of another identified comorbidity. HOD should be considered in any young, large-breed dog with generalized ostealgia and signs of systemic illness, even in the absence of classic radiographic abnormalities. Further investigation of coagulation status in dogs with HOD and a secondary systemic inflammatory response is warranted.