Experimental Design and Surgical Approach to Create a Spinal Fusion Model in a New Zealand White Rabbit (Oryctolagus cuniculus)

There are several animal models routinely used for study of the spinal fusion process and animal selection largely depends on the scientific question to be answered. This review outlines the advantages and disadvantages of various animal models used to study spinal fusion and describes the New Zealand White (NSW) rabbit which is the most popular preclinical model to study spinal fusion. We outline critical steps required in planning and performing spinal fusion surgery in this model. This includes determination of the required animal number to obtain statistical significance, an outline of appropriate technique for posterolateral fusion and other components of completing a study. As advances in drug delivery move forward and our understanding of the cascade of gene expression occurring during the fusion process grows, performing and interpreting preclinical animal models will be vital to validating new therapies to enhance spinal fusion.     

Papillary thyroid carcinomas with and without BRAF V600E mutations are morphologically distinct

Finkelstein A, Levy G H, Hui P, Prasad A, Virk R, Chhieng D C, Carling T, Roman S A, Sosa J A, Udelsman R, Theoharis C G & Prasad M L
(2012) Histopathology  60, 1052–1059 Papillary thyroid carcinomas with and without BRAF V600E mutations are morphologically distinct Aims: The BRAF V600E mutation resulting in the production of an abnormal BRAF protein has emerged as the most frequent genetic alteration in papillary thyroid carcinomas (PTCs). This study was aimed at identifying distinctive features in tumours with and without the mutation. Methods and results: Thirty‐four mutation‐positive and 22 mutation‐negative tumours were identified by single‐strand conformation polymorphism of the amplified BRAF V600E region in the tumour DNA. Mutation‐positive tumours were more common in patients older than 45 years (24/33, P = 0.05), in classic (23/30, P = 0.01), tall cell (4/5) and oncocytic/Warthin‐like (2/2) variants of PTC, and in subcapsular sclerosing microcarcinomas (4/4). In contrast, all 12 follicular variants (P < 0.0001) and two diffuse sclerosing variants were negative for the mutation. Mutation‐positive tumours displayed infiltrative growth (32/34, P = 0.02), stromal fibrosis (33/34, P < 0.001), psammoma bodies (17/34, P = 0.05), plump eosinophilic tumour cells (22/34, P = 0.01), and classic fully developed nuclear features of PTC (33/34, P = 0.0001). Encapsulation was significantly associated with mutation‐negative tumours (15/22, P = 0.02). Conclusions: BRAF V600E mutation‐positive and negative PTCs are morphologically different. Recognition of their morphology may help in the selection of appropriate tumours for genetic testing.     

International travel and exposure risks in solid-organ transplant recipients

BACKGROUND: Although solid-organ transplant recipients (SOTR) have an increased risk of acquiring illnesses, they may not receive optimal pretravel care. We conducted a cross-sectional survey of travel activities and outcomes among SOTR. METHODS: Two thousand five hundred fifty-four consecutive living SOTR from Mayo Clinic were surveyed regarding travel practices, pretravel counseling, exposure risks, and illness using a previously standardized and validated questionnaire. RESULTS: One thousand one hundred thirty SOTR (44%) responded to the survey and were included in the study. The most common transplanted organs were liver (519 patients) and kidney (515 patients). Three hundred and three (27%) respondents reported travel outside of the United States or Canada after their transplant. Liver recipients were more likely to travel than other organ recipients. Ninety-six percent of travelers reported that they did not seek specific pretravel healthcare before their trip. Forty-nine SOTR (16%) traveled to destinations at higher risk for infectious diseases; travelers to these destinations were more likely to be men (73% vs. 54% of low-infection risk travelers, P=0.018) or born outside the United Stated or Canada (29% vs. 6% P<0.0001). Twenty-four travelers (8%) required medical attention because of illness; illness was more likely among travelers to high-infection risk (18%) than low-risk (6%) destinations, P=0.004. CONCLUSIONS: International travel was common after solid organ transplantation, although the majority traveled to destinations at low risk for infectious disease. Although generally SOTR were able to travel safely, travelers to destinations at high-risk for infection had a significant rate of illness. Pretravel counseling and interventions were infrequent and should be improved.     

Mechanism of drug resistance in clonally related clinical isolates of Vibrio fluvialis isolated in Kolkata, India

The molecular mechanisms of drug resistance in 19 strains of Vibrio fluvialis isolated from 1998 to 2002 in Kolkata, India, were investigated. Class 1 integrons were detected in eight strains, and four strains were found to carry SXT integrases. In the presence of carbonyl cyanide m-chlorophenylhydrazone or reserpine, all nalidixic acid- and ciprofloxacin-resistant strains became sensitive, suggesting that drug efflux plays a major role in quinolone resistance in V. fluvialis. It was further seen that strains which had MICs of > 25 microg/ml for nalidixic acid had a sense mutation (Ser to Ile) at position 83 of the quinolone resistance-determining region of gyrA. All except one of the integron- and SXT integrase-bearing strains belonged to the same ribotype.