Backspatter from experimental close-range shots to the head

Backspatter is the ejection of biological material from a gunshot entrance wound against the line of fire. This phenomenon was investigated experimentally in transverse gunshots to the heads of calves (n = 9) using two types of 9 mm Parabellum ammunition from shooting distances of 0–10 cm. The resulting bloodstains were documented on white paper placed horizontally 60 cm below the impact site. In this report the analysis was restricted to stains with a diameter > 0.5 mm. Backspatter was documented after every gunshot. The number of stains varied from 31–324 per gunshot and appeared to be independent of the shooting distance. The maximum distance droplets travelled varied from 72–119 cm. The majority of droplets accumulated between 0 and 50 cm. The number of droplets and the distances travelled should be higher in man for anatomical reasons. The direction a single droplet can take comprises every possible angle between the most tangential ones to the skin surface. This resulted in a semi-circle of 180° covered with stains. Skin ruptures of the entrance wound were not observed. The succession of events was documented on high speed film and started with the recoil of the firearm, immediately followed by a blow-out effect of the skin. Large droplets exited approximately 0.7–4 ms after the bullet impacted the skin. The calculated minimum initial velocity of these droplets was 13–61 m/s. Backspatter from gunshots to the head likely is caused by the hot gases expanding subcutaneously and by cavitation-related intracranial overpressure and tail splashing. In three out of nine gunshots, secondary backspatter additionally occurred as a result of droplets produced by a stream of blood from the entrance wound impacting the paper surface.     

Proposed definition of a smokeless tobacco user based on “potential” nicotine consumption

This study examined and operationally defined "light," "moderate," and "heavy" users of smokeless tobacco according to the potential amounts of nicotine consumed per week from chewing tobacco and/or snuff products. Fifty adult male smokeless tobacco users ranging in ages from 18-85 were tested to determine nicotine content of smokeless tobacco products consumed. The smokeless tobacco products were blindly analyzed by gas chromatography to determine nicotine content. Mean nicotine yield per week was calculated by multiplying the number of cans and/or pouches used per week and placed on a normal probability distribution. The mean nicotine yielded 238 mg/wk and the categories emerged as "light" less than or equal to 87 mg/wk, "moderate" 88-388 mg/wk and "heavy" users greater than or equal to 389 mg/wk. Differences regarding type of user (light, moderate, heavy) were crossed tabbed with educational levels, years of smokeless tobacco use, age the habit was initiated, perception of harm and whether habit forming, and reason for using smokeless tobacco.     

Dose response, coasting, and differential fiber vulnerability in human toxic neuropathy: a prospective study of pyridoxine neurotoxicity.

We administered either 1 or 3 g/d of pyridoxine (vitamin B6) to five healthy volunteers and repeatedly followed serum pyridoxal phosphate levels, clinical symptoms and signs, quantitative sensory thresholds (QSTs), and sural nerve electrophysiology. Pyridoxine was discontinued at the first sign of either clinical or laboratory abnormality. In all subjects, sensory symptoms and QST abnormalities occurred concurrently. Subjects receiving higher doses became symptomatic earlier than low-dose subjects. Elevation of thermal QSTs preceded or exceeded that for vibration in the three low-dose subjects; vibration and thermal QST became abnormal simultaneously in the higher-dose subjects. A reduction in the amplitude of the sural sensory potential lagged behind QST changes in two of three subjects. Symptoms continued to progress ("coasting") for 2 to 3 weeks despite stopping pyridoxine administration and the return of serum pyridoxal phosphate levels to normal. This study suggests that (1) there is a clear dose-percent relationship for pyridoxine-induced neuropathy, (2) QST is a sensitive measurement for detecting early peripheral neuropathy; QST abnormalities may precede changes in nerve conduction studies, (3) coasting appears unrelated to persistently elevated blood levels of the toxin, and (4) a dose-dependent vulnerability may exist among nerve fibers of different caliber when exposed to an axonal toxin, such as pyridoxine.     

Surgical indications status in ileus using a simple clinical index

Based on a retrospective analysis of a group of patients with ileus disease in regard of the indication for operative intervention an "ileus index" was created which is derived from simple clinical and radiological findings and laboratory data. Prospective evaluation of this index showed its effectiveness in separating patients who had to undergo an emergency operation from those who could be operated electively after preceding diagnostic procedures or could be treated conservatively.     

In vitro studies on the effect of delaminated a-C:H film fragments on bone marrow cell cultures

Amorphous hydrogenated carbon (a-C:H) films have many outstanding properties required for a protective coating material on load bearing medical implants. Recently, titanium doped a-C:H films have been evaluated regarding their effects on bone marrow cell cultures. But many materials that are well-tolerated in bulk form are able to induce toxic reaction if present particulate form. In order to further assess biocompatibility aspects of these two coatings, film delamination has been mimicked in exposure to fluids. In the present study, particles from a-C:H, a-C:H/Ti and a-C:H-a-C:H/Ti bilayer films were added to bone marrow cell cultures in vitro. The results showed that plain a-C:H and to a certain extent a-CH/Ti particles were inert. Both kinds of particles did not significantly stimulate the osteoclast-related enzyme tartrate resistant acid phosphatase (TRAP). A slight increase in cell proliferation and total culture TRAP was found in cultures treated by a-C:H-a-C:H/Ti bilayer films. Latter effect can probably be traced back by the relative high percentage of small particles of a size of around 2 microm. However, if corrected by the cell number also no differences between particle-treated and untreated control cultures could be found, indicating the absence of a toxic effect from delaminated a-C:H coatings.     

Small bowel transplantation in a child. Morphologic, immunohistochemical, and clinical results

A small bowel transplant was performed on a five-year-old boy with a short bowel syndrome. The donor was the child's mother. Despite immunosuppressive therapy, the transplant was acutely rejected and had to be explanted on the twelfth day. Morphologic and immunohistochemical investigations on subsequent biopsies taken from the small bowel transplant were carried out. Besides typical changes in epithelial cells and the presence of T-cell infiltrates and Ig-deposits in vessels, many macrophages were seen. The submucosa in particular was invaded before rejection by numerous macrophages with positive results of antimonocyte/macrophage antibodies Ki-M6 and Ki-M7. The number of the macrophage antibodies Ki-M6 and Ki-M7. The number of the monocyte/macrophage cells and the immunohistochemical characteristics of the same may be important parameters for monitoring small bowel transplantations.     

Gender and smoking-related risk reduction of periodontal disease with variant myeloperoxidase alleles

Myeloperoxidase (MPO) is an oxidative enzyme expressed in polymorphonuclear leukocytes. It is involved in the defence against periodontal bacteria, and is also able to mediate inflammatory tissue destruction in periodontal disease. A G/A polymorphism in the promoter region of the MPO gene at position -463 has been assumed to exert profound effects on the expression of the enzyme. It is the aim of this study to evaluate whether this polymorphism may influence the risk of periodontal diseases. A total of 3148 subjects were randomly selected from the general population in the SHIP study (Study of Health in Pomerania). Periodontal status, health-related and socio-economic items were assessed. All subjects aged 40-60 years (n = 1103) were included in this study, and 1083 genotyped for the MPO -463 G/A polymorphism by PCR and RFLP methods. The genotype frequencies determined were homozygous wild type G/G 65.9% (95% CI 63.5-68.6), heterozygous A/G 31.4% (28.8-34.4), and homozygous variant A/A 2.7% (2.0-3.8). Only female subjects have a significantly reduced risk of severe periodontal disease when bearing the variant genotypes A/G or A/A. In female subjects the reduction in periodontal risk was significant for non-smokers (OR = 0.48; 95% CI 0.23-0.96); the smoke-related increase in risk was also reduced (OR = 0.50; 95% CI 0.22-1.10). When adjusted for age, smoking, and education the odds ratios were calculated as 0.52 (P = 0.01) and 0.97 (P = 0.90) for female and male subjects, respectively. The results of this study confirm the assumption that the MPO -463A allele variants are protective in the pathogenesis of periodontal diseases. This holds true only with women but not with men. The results are discussed with respect to the known influences of sexual hormones on MPO activity.     

Prevalence and phylogenetic characterisation of TT-virus in the blood donor population of Auckland, New Zealand

TT-virus (TTV, patient initials: T.T.), a novel DNA virus, was first isolated in Japan in 1997 from serum of a patient with post-transfusion hepatitis of unknown aetiology. To date, the contribution of TTV to liver disease remains doubtful. The potential for transmission via blood and blood products makes it essential to establish the prevalence of TTV viraemia in the blood donor population. 413 blood donor serum samples were chosen randomly, the DNA was extracted and TTV-specific DNA amplified by nested polymerase chain reaction (PCR). TTV infection was present in 13 out of 413 (3.15%) blood donors in the Auckland region of New Zealand using a set of primers targeting open reading frame (ORF) 1. These 13 amplification products (264 bp) were sequenced and TTV genotypes determined. Alignment with published TTV sequences showed that seven (53.8%) of the thirteen positive serum samples belonged to genotype 1, five (38.5%) belonged to genotype 2 and one (7.7%) could not be classified as either genotype 1 or 2. One hundred twenty-seven blood donor serum samples were retested with a second set of primers targeting the 5' region of the TTV genome in a single round PCR. Forty-three samples were positive for TTV DNA with these primers resulting in a prevalence of 37%. The data demonstrate that TTV is present among New Zealand blood donors and support the need for further investigation into the natural history of TTV infection.     

Case of synovitis potentially caused by Dolosigranulum pigrum

We report a case of synovitis in a 64-year-old man who developed the infection while on steroid therapy for rheumatoid arthritis. Dolosigranulum pigrum, a gram-positive catalase-negative coccus, was isolated from two sets of blood cultures prior to antibiotic therapy. The patient was treated with 4 weeks of appropriate antibiotics, and the synovial inflammation resolved. Although synovial aspirates were never positive for any bacteria or fungi, the timing of positive blood cultures and absence of other pathogens suggest the possible etiology as D. pigrum.