Calibrant-Free Analyte Quantitation via a Variable Velocity Flow Cell.

In this paper, we describe a novel method for analyte quantitation that does not rely on calibrants, internal standards, or calibration curves but, rather, leverages the relationship between disparate and predictable surface-directed analyte flux to an array of sensing addresses and a measured resultant signal. To reduce this concept to practice, we fabricated two flow cells such that the mean linear fluid velocity, U, was varied systematically over an array of electrodes positioned along the flow axis. This resulted in a predictable variation of the address-directed flux of a redox analyte, ferrocenedimethanol (FDM). The resultant limiting currents measured at a series of these electrodes, and accurately described by a convective-diffusive transport model, provided a means to calculate an "unknown" concentration without the use of calibrants, internal standards, or a calibration curve. Furthermore, the experiment and concentration calculation only takes minutes to perform. Deviation in calculated FDM concentrations from true values was minimized to less than 0.5% when empirically derived values of U were employed.

Ecology of Bats, Their Ectoparasites, and Associated Pathogens on Saint Kitts Island.

Ectoparasites of bats and bat-associated pathogens are poorly studied in the Lesser Antilles Islands. We report on an 11-mo field study on Saint Kitts Island of bat populations, their associated ectoparasites, and pathogens. We report on five ectoparasite species, including four Streblidae (Diptera) and a Spinturnicidae (Acari). Several genotypes of unnamed Bartonella were isolated from bats and ectoparasites. Microfilaria of an undetermined Litomosoides spp. were detected in blood from Artibeus jamaicensis Leach (Chiroptera: Phyllostomidae) (and associated ectoparasites: Trichobius intermedius Peterson and Hurka (Diptera: Streblidae) and Periglischrus iheringi Oudemans (Acari: Spinturnicidae)). In addition, an Ehrlichia sp. and Rickettsia africae were detected in the blood of several bat species. Our study is one of the first surveys of ectoparasite-borne pathogens in wild mammals from St. Kitts.

Surgical management of vertebral malformation in a Manx cat.

A 15-week-old Manx kitten was presented for evaluation of progressive hind limb paresis and ataxia. Spinal radiographs and computed tomography revealed a malformation of T3 causing thoracic spinal cord compression. Decompressive surgery consisting of dorsal laminectomy, without vertebral stabilisation, resulted in improvement of clinical signs.

Outcomes of cellophane banding for congenital portosystemic shunts in 106 dogs and 5 cats.

OBJECTIVE: To report outcomes after cellophane banding of single congenital portosystemic shunts in dogs and cats. STUDY DESIGN: Retrospective study of sequential cases. ANIMALS: One hundred and six dogs and five cats. METHODS: Medical records were reviewed for breed, sex, age at surgery, shunt anatomy, results of pre- and postoperative biochemical analysis, development of postligation neurologic dysfunction, portal hypertension or other serious complications, and the owners' perception of their animal's response to surgery. RESULTS: Ninety-five dogs and all 5 cats had extrahepatic shunts. Eleven dogs had intrahepatic shunts. Six dogs (5.5%) died as a result of surgery from portal hypertension (2 dogs), postligation neurologic dysfunction (2), splenic hemorrhage (1) and suspected narcotic overdose (1). Serious complications were more common in dogs with intrahepatic shunts than those with extrahepatic shunts (P=.002). Postligation neurologic dysfunction necessitated treatment in 10 dogs and 1 cat; 8 dogs and the cat survived. Clinical signs attributed to portosystemic shunting resolved or were substantially attenuated in all survivors. Postoperative serum bile acid concentrations or results of ammonia tolerance testing were available for 88 animals; 74 (84%) were normal and 14 (16%) were abnormal. Multiple acquired shunts were documented in two animals. CONCLUSIONS: Cellophane banding is a safe and effective alternative to other methods of attenuation. CLINICAL RELEVANCE: Slow occlusion of portosystemic shunts using a variety of methods is being evaluated world wide. Cellophane banding is a relatively simple procedure with comparable safety and efficacy to previously reported techniques.

Digital radiography in the diagnosis of Toddler's fracture.

BACKGROUND: The objective of this study was to evaluate the accuracy of digital imaging in the diagnosis of toddler's fractures. METHODS: Medical records for a 9.4-year period were reviewed to locate children whose initial radiographs were interpreted as normal by a pediatric radiologist and whose subsequent bone scans or follow-up radiographs showed toddler's fractures. Radiographs from these children (ie, positive controls) and from children without toddler's fractures (ie, negative controls) were digitized to create a film bank that was reviewed by a panel of 14 physicians with various medical backgrounds. Medical records were reviewed for demographic information, findings on history and physical examination, and radiographic and laboratory tests. RESULTS: Pediatric radiology physicians correctly diagnosed 73.2 +/- 5.4% of the digitized images, as compared with pediatric emergency physicians, 66.7 +/- 6.5% and residents/fellows, 57.1 +/- 6.9%. CONCLUSION: Digitized images may be helpful in evaluating limping children with suspected toddler's fractures, possibly eliminating the need for further diagnostic studies.