GSR deposition along the bullet path in contact shots to composite models

In contact shots, all the materials emerging from the muzzle (combustion gases, soot, powder grains, and metals from the primer) will be driven into the depth of the entrance wound and the following sections of the bullet track. The so-called "pocket" ("powder cavity") under the skin containing soot and gunpowder particles is regarded as a significant indicator of a contact entrance wound since one would expect that the quantity of GSR deposited along the bullet's path rapidly declines towards the exit hole. Nevertheless, experience has shown that soot, powder particles, and carboxyhemoglobin may be found not only in the initial part of the wound channel, but also far away from the entrance and even at the exit. In order to investigate the propagation of GSRs under standardized conditions, contact test shots were fired against composite models of pig skin and 25-cm-long gelatin blocks using 9-mm Luger pistol cartridges with two different primers (Sinoxid® and Sintox®). Subsequently, 1-cm-thick layers of the gelatin blocks were examined as to their primer element contents (lead, barium, and antimony as discharge residues of Sinoxid® as well as zinc and titanium from Sintox®) by means of X-ray fluorescence spectroscopy. As expected, the highest element concentrations were found in the initial parts of the bullet tracks, but also the distal sections contained detectable amounts of the respective primer elements. The same was true for amorphous soot and unburned/partly burned powder particles, which could be demonstrated even at the exit site. With the help of a high-speed motion camera it was shown that for a short time the temporary cavitation extends from the entrance to the exit thus facilitating the unlimited spread of discharge residues along the whole bullet path.

Predicting the pathogen of diabetic toe osteomyelitis by two consecutive ulcer cultures with bone contact

In this study, we investigate the accuracy of two consecutive ulcer cultures with bone contact compared to bone biopsy for the diagnosis of diabetic toe osteomyelitis. The same nurse and orthopaedic surgeon obtained all samples: sample A-1: bone contact swabbing through the ulcer; sample A-2: a second culture swabbing from the bone surface within 24 h; sample B: surgical bone biopsy in the operating theatre. The kappa statistic measure between samples A-1 and A-2 (bone contact swabs) indicated 82.35% agreement. The sensitivity, specificity, positive and negative predictive values of the two samples A compared to B were 96%, 79%, 92% and 88%, respectively, for the causative pathogen. These results were similar with prior antibiotic treatment, discordant bone surface swabs or with monomicrobial infections. As a conclusion, two consecutive diabetic toe cultures with bone contact accurately predict the pathogen of diabetic toe osteomyelitis in 90% of cases.

Nano-stenciled RGD-gold patterns that inhibit focal contact maturation induce lamellipodia formation in fibroblasts

Cultured fibroblasts adhere to extracellular substrates by means of cell-matrix adhesions that are assembled in a hierarchical way, thereby gaining in protein complexity and size. Here we asked how restricting the size of cell-matrix adhesions affects cell morphology and behavior. Using a nanostencil technique, culture substrates were patterned with gold squares of a width and spacing between 250 nm and 2 µm. The gold was functionalized with RGD peptide as ligand for cellular integrins, and mouse embryo fibroblasts were plated. Limiting the length of cell-matrix adhesions to 500 nm or less disturbed the maturation of vinculin-positive focal complexes into focal contacts and fibrillar adhesions, as indicated by poor recruitment of ?5-integrin. We found that on sub-micrometer patterns, fibroblasts spread extensively, but did not polarize. Instead, they formed excessive numbers of lamellipodia and a fine actin meshwork without stress fibers. Moreover, these cells showed aberrant fibronectin fibrillogenesis, and their speed of directed migration was reduced significantly compared to fibroblasts on 2 µm square patterns. Interference with RhoA/ROCK signaling eliminated the pattern-dependent differences in cell morphology. Our results indicate that manipulating the maturation of cell-matrix adhesions by nanopatterned surfaces allows to influence morphology, actin dynamics, migration and ECM assembly of adhering fibroblasts.

Oral lichenoid contact lesions induced by areca nut and betel quid chewing: a mini review

Betel quid (BQ) and areca nut chewing is widely prevalent in many parts of Asia and Asian-migrant communities throughout the world. Global reports estimate 600 million users. Sufficient evidence of carcinogenicity has been found for BQ and its main ingredient, areca nut. BQ areca nut users have an increased risk of potentially malignant disorders. Among chewers, BQ remains in contact with the oral mucosa for prolonged periods. This review examines the clinical and pathological aspects of lichenoid lesions caused by areca nut and BQ, a condition that has received little attention in the published literature.

Assessment of exposure to Leptospira serovars in veterinary staff and dog owners in contact with infected dogs

OBJECTIVE: To assess patterns of seroreactivity to Leptospira serovars in veterinary professional staff and dog owners exposed to dogs with acute leptospirosis and to contrast these patterns in people with those observed in dogs. DESIGN: Cross-sectional study. SAMPLE POPULATION: Human subjects consisted of 91 people (50 veterinarians, 19 technical staff, 9 administrative personnel, and 13 dog owners) exposed to dogs with leptospirosis. Canine subjects consisted of 52 dogs with naturally occurring leptospirosis admitted to the University of Bern Vetsuisse Faculty Small Animal Clinic in 2007 and 2008. PROCEDURES: People were tested for seroreactivity to regionally prevalent Leptospira serovars by use of a complement fixation test. A questionnaire designed to identify risk factors associated with seropositivity was used to collect demographic information from each study participant. Dogs were tested for seroreactivity to Leptospira serovars by use of a microscopic agglutination test. RESULTS: On the basis of microscopic agglutination test results, infected dogs were seropositive for antibodies against Leptospira serovars as follows (in descending order): Bratislava (43/52 [83%]), Australis (43/52 [83%]), Grippotyphosa (18/52 [35%]), Pomona (12/52 [23%]), Autumnalis (6/52 [12%]), Icterohemorrhagiae (4/52 [8%]), Tarassovi (2/52 [4%]), and Canicola (1/52 [2%]). All 91 people were seronegative for antibodies against Leptospira serovars. Therefore, statistical evaluation of risk factors and comparison of patterns of seroreactivity to Leptospira serovars between human and canine subjects were limited to theoretical risks. CONCLUSIONS AND CLINICAL RELEVANCE: Seroreactivity to Leptospira serovars among veterinary staff adhering to standard hygiene protocols and pet owners exposed to dogs with acute leptospirosis was uncommon.