Erratum to: Head/skull injury potential of empty 0.5-l beer glass bottles vs. 0.33-l Coke bottles.

In the context of further impact tests with various striking weapons against the skull, it turned out that the manufacturer had incorrectly calibrated the force measuring plate, which was used in our earlier experiments. When the tests were carried out again under the same conditions, the measurement results were significantly higher.

Head/skull injury potential of empty 0.5-l beer glass bottles vs. 0.33-l Coke bottles.

The medical and biomechanical assessment of injuries from blows to the head is a common task in forensic medicine. In the context of a criminal justice process, the injury potential of different striking weapons is important. The article at hand compares the injury potential of assaults with a 0.5-l beer bottle and a 0.33-l Coke bottle, both made of glass. The research team hit 30 used empty 0.5-l beer bottles and 20 used empty 0.33-l Coke bottles manually on an aluminum dummy skull set on a force measuring plate, using acrylic and pork rind as a scalp surrogate. There was no significant difference in fracture threshold and energy transfer between the examined beer and Coke bottles. Both glass bottles are able to cause fractures to the facial bones while cranial bone fractures are primarily not to be expected. Blows with a 0.5-l beer bottle or with a 0.33-l Coke bottle to the head can transfer up to 1.255 N and thus are able to cause severe blunt as well as sharp trauma injuries.

Beer stein blast to the head a rare case of combined blunt and sharp force trauma.

Cases of combined blunt and sharp force trauma to the head caused by one striking tool are rare. When beer steins are used as an assault weapon, they can cause blunt traumas upon initial contact phase. If the impact force exceeds the mechanical stability of the beer stein, it breaks into several sharp-edged pieces, which then can cause sharp force trauma injuries due to the interaction between the head and the stein fragments.We present a case of a 43-year old man, who suffered from blunt and sharp force head traumas due to one single blow with a 1-l beer stein. A forensic-biomechanical analysis of the event, together with witness testimony evaluation and experimental comparison helped to reconstruct the most probable chain of events. Based on these findings as well as on the medical diagnoses and treatment, the assault was assessed as a nonacute life-threatening, but potentially fatal offence. The case was indicted as grievous bodily harm.

Injury potential of one-litre beer steins.

Injuries resulting from blows with beer steins are a frequent occurrence during annual autumn fairs or at beer halls in South Germany and Austria. The majority of these cases are tried in court and thus being assessed by a forensic medicine expert. The article at hand gives a short overview on the injury potential of one-litre beer steins and explains the key variables to consider when analyzing beer stein injuries. On the basis of representative cases, which were assessed by specialists from the Institute of Legal Medicine of the Munich University over the last 5 years, the main biomechanical aspects and resulting injuries of one-litre beer stein assaults are discussed. Several severe and potentially life-threatening injuries have been observed after an assault with a one-litre beer stein. There is a discrepancy between the mechanical stability of brand new and used steins and the corresponding injuries, which can be explained by a decrease in impact tolerance of the steins with their use. In general, a blow with a one-litre glass or stonework beer stein to the head can cause severe and even life-threatening blunt as well as sharp trauma injuries.

Adrenergic and metabolic effects of electrical weapons: review and meta-analysis of human data.

INTRODUCTION: Electronic control with the CEW (conducted electrical weapon) has gained widespread acceptance as the preferred force option due to its significant injury reduction. However, a CEW application does stress the human body. In the case of the CEW, the human body response is similar to the challenge of physical exercise combined with emotional stress over a very short time interval. There has been concern whether the tension of the skeletal-muscle system together with the emotional stress of being exposed to the effects of a CEW, can lead to severe metabolic dysfunction. METHODS: A systematic and careful search of the MedLine database was performed to find publications describing pathophysiological effects of CEWs. Additional publications were collected through a manual search of reference lists in retrieved articles. After preliminary exclusions, we carefully reviewed the remaining publications and found 24 papers reporting prospective human clinical research data on adrenergic, ventilation, or metabolic effects. Where there were multiple studies on the same endpoints, we performed meta-analyses. RESULTS: A CEW exposure provides a clinically insignificant increase in heart rate (7.5 BPM) and a drop in both systolic and diastolic blood pressure. Alpha-amylase goes down but cortisol levels increase-both epinephrine and norepinephrine levels are increased by levels similar to mild exercise. A CEW exposure increases ventilation but does not appear to interfere with gas exchange. Lactate is increased slightly while the pH is decreased slightly with changes equivalent to mild exercise. The lactate and pH changes appear quickly and do not appear to be affected by increasing the exposure duration from 5 to 30 s. CONCLUSIONS: Thorough review and meta-analyses show that electrical weapon exposures have mixed and mild adrenergic effects. Ventilation is increased and there are metabolic changes similar to mild exercise.

A proclaimed accidental fall of an infant-an experimental case reconstruction study.

The differentiation between a non-accidental injury and injuries resulting from accidents, such as falls to the ground or onto various objects, is a challenge not only for forensic experts but also for all clinicians caring for children. The forensic-biomechanical analysis of accidents in infants aims at the assessment of the loading characteristics based on the reconstruction of the particular incident. It includes an evidence-based analytical comparison between the actual injuries presented and the injuries that should be expected as a result of the proclaimed accident. With the help of kinematical and dynamical parameters of the described actions and the resulting loading situations, the forensic-biomechanical analysis can assess the plausibility of the proclaimed course of the event and thus contribute to the differentiation between accidental and non-accidental injuries. The quality of such a forensic-biomechanical expert opinion depends on the accuracy and quantity of available data regarding biomechanical tolerance of tissues, organs, and body parts. Case-specific measurements can contribute significantly to the insight of the kinematics and dynamics of the proclaimed event, its feasibility, etc. The present article demonstrates, based on one case report, the potential as well as the limits of such an analysis of proclaimed accidental fall injuries.

Vascular stenosis asymmetry influences considerably pressure gradient and flow volume.

Vascular stenosis is often described only by its percentage in both clinical and scientific praxis. Previous studies gave inconclusive results regarding the effect of stenosis eccentricity on its hemodynamic effect. The aim of this experimental study was to investigate and quantify the effect of stenosis severity and eccentricity on the pressure drop. A combination of pressure and flow measurements by Particle Imaging Velocimetry (PIV) method was used. Models of the same stenosis significance but with different levels of eccentricity were studied in vitro by PIV. This study has shown that stenosis asymmetry is associated with more profound pressure drop and flow volume decrease. On the contrary, pressure drop and flow volume decrease were not further significantly influenced by the level of asymmetry. Hemodynamic changes associated with stenosis eccentricity must be taken into account in both clinical and scientific studies.

Secretoglobin and Transferrin Expression in Bronchoalveolar Lavage Fluid of Horses with Chronic Respiratory Disease.

BACKGROUND: Lower expression of secretoglobin and transferrin has been found in the bronchoalveolar lavage fluid (BALF) of a small number of horses with experimentally induced signs of recurrent airway obstruction (RAO) compared to healthy controls. HYPOTHESIS/OBJECTIVES: Secretoglobin and transferrin BALF expression will be similarly decreased in horses with naturally occurring clinical signs of RAO and in horses with experimentally induced clinical signs of RAO as compared to healthy controls and intermediate in horses with inflammatory airway disease (IAD). ANIMALS: Recurrent airway obstruction-affected and control horses were subjected to an experimental hay exposure trial to induce signs of RAO. Client-owned horses with a presumptive diagnosis of RAO and controls from the same stable environments were recruited. METHODS: Pulmonary function and BALF were evaluated from control and RAO-affected research horses during an experimental hay exposure trial (n = 5 in each group) and from client-owned horses (RAO-affected horses, n = 17; IAD-affected horses, n = 19; healthy controls, n = 5). The concentrations of secretoglobin and transferrin in BALF were assessed using Western blots. RESULTS: Naturally occurring and experimentally induced RAO horses had similar decreases in BALF transferrin expression, but secretoglobin expression was most decreased in naturally occurring RAO. Secretoglobin and transferrin expression were both lower in BALF of RAO-affected horses than in IAD-affected and control horses. CONCLUSIONS AND CLINICAL IMPORTANCE: Secretoglobin and transferrin expression is decreased in BALF of RAO-affected horses after both experimental and natural exposure. Secretoglobin and transferrin likely play clinically relevant roles in the pathophysiology of RAO, and may thus be used as biomarkers of the disease.

Common carotid wall shear stress and carotid atherosclerosis in end-stage renal disease patients.

Decrease of arterial wall shear stress (WSS) is associated with higher probability of atherosclerotic plaque development in many disease conditions. End-stage renal diseases (ESRD) patients suffer from vascular disease frequently, but its nature differs from general population. This study was aimed at proving an association between common carotid wall shear stress and the presence of carotid bifurcation plaques in a group of ESRD patients. ESRD subjects, planned for the creation of a dialysis access and therapy were included. Wall shear rate (WSR) was used as a surrogate of WSS and was analyzed in the common carotid arteries by duplex ultrasonography. Intima media thickness (IMT) was measured at the same site. The presence/absence of carotid bifurcation plaques was recorded. The endothelial function was estimated by the levels of von Willebrand factor (vWf). 35 ESRD patients were included (19 females, 17 diabetics). Atherosclerotic plaque was present in 53 % of bifurcations. Wall shear rate was lower in arteries with plaques (349+/-148 vs. 506+/-206 s(-1), p=0.005) and was directly related to the height of IMT and inversely to the activity of vWf (r= -0.65, p=0.016). Lower wall shear rate in the common carotid arteries is linked to the endothelial dysfunction and to the presence of atherosclerotic plaques in carotid bifurcations in ESRD subjects. Faster arterial dilatation may facilitate this process in ESRD subjects.

The crossed leg sign indicates a favorable outcome after severe stroke.

OBJECTIVE: We investigated whether crossed legs are a prognostic marker in patients with severe stroke. METHODS: In this controlled prospective observational study, we observed patients with severe stroke who crossed their legs during their hospital stay and matched them with randomly selected severe stroke patients who did not cross their legs. The patients were evaluated upon admission, on the day of leg crossing, upon discharge, and at 1 year after discharge. The Glasgow Coma Scale, the NIH Stroke Scale (NIHSS), the modified Rankin Scale (mRS), and the Barthel Index (BI) were obtained. RESULTS: Patients who crossed their legs (n = 34) and matched controls (n = 34) did not differ in any scale upon admission. At the time of discharge, the GCS did not differ, but the NIHSS was better in crossed legs patients (6.5 vs 10.6; p = 0.0026), as was the mRS (3.4 vs 5.1, p < 0.001), and the BI (34.0 vs 21.1; p = 0.0073). At 1-year follow-up, mRS (2.9 vs 5.1, p < 0.001) and the BI (71.3 vs 49.2; p = 0.045) were also better in the crossed leg group. The mortality between the groups differed grossly; only 1 patient died in the crossing group compared to 18 in the noncrossing group (p < 0.001). CONCLUSION: Leg crossing is an easily obtained clinical sign and is independent of additional technical examinations. Leg crossing within the first 15 days after severe stroke indicates a favorable outcome which includes less neurologic deficits, better independence in daily life, and lower rates of death.

Bowman-Birk inhibitor affects pathways associated with energy metabolism in Drosophila melanogaster.

Bowman-Birk inhibitor (BBI) is toxic when fed to certain insects, including the fruit fly, Drosophila melanogaster. Dietary BBI has been demonstrated to slow growth and increase insect mortality by inhibiting the digestive enzymes trypsin and chymotrypsin, resulting in a reduced supply of amino acids. In mammals, BBI influences cellular energy metabolism. Therefore, we tested the hypothesis that dietary BBI affects energy-associated pathways in the D. melanogaster midgut. Through microarray and metabolomic analyses, we show that dietary BBI affects energy utilization pathways in the midgut cells of D. melanogaster. In addition, ultrastructure studies indicate that microvilli are significantly shortened in BBI-fed larvae. These data provide further insights into the complex cellular response of insects to dietary protease inhibitors.

Particle image velocimetry measurement in the model of vascular anastomosis.

Neointimal hyperplasia is the most common complication of all forms of arterial reconstructions. This response of the vascular wall to injury is influenced by many factors, especially, but not limited to, by the hemodynamic profile in the area of vascular anastomosis and in its close proximity. To eliminate this negative influence of hemodynamics on progression of neointimal hyperplasia, we tried to develop anastomosis with optimal hemodynamic parameters. In our experimental study we used Particle Image Velocimetry measurement and 3D blood flow simulation for studying flow characteristics for different length and angles of anastomoses. Based on our experimental studies and numerical simulations we believe that anastomosis with smaller angle demonstrates better hemodynamic parameters, optimal angle being less than 30 dg. Length of anastomosis in this smaller angle anastomosis is app. 2-2.5 of native vessel diameter.

Hybrid molecules of estrone: new compounds with potential antibacterial, antifungal, and antiproliferative activities.

New hybrid molecules of estrone were synthesized as compounds indicating promising biological activity (antibacterial, antimycobacterial, antifungal, and antiproliferative). The prepared molecules contained various heterocyclic units (pyridine, benzylsulfanyl derivatives of pyridine or derivatives of tetrazole) linked to estrone by n-heptyl bridges. The compounds with charge on molecule (the hybrid pyridinium or benzylsulfanylpyridinium salts) exhibited significant biological activity (antibacterial, antimycobacterial, antifungal, and antiproliferative). On the other hand, the compounds not in the form of salts (omega-(1-phenyl-5-tetrazolylthio)heptylethers of estrone) were inactive. The antimycobacterial activities of three different series of tetrazole derivatives (i.e., the hybrid molecules with estrone, tetrazole-5-thiols, and 5-benzylsulfanyl-1-phenyltetrazoles) with the same substituents on phenyl ring were compared. Amongst them, the 5-benzylsulfanyl-1-phenyltetrazoles were the most potent.

1-Aryl-5-benzylsulfanyltetrazoles, a new group of antimycobacterial compounds against potentially pathogenic strains.

A set of 21 1-phenyl-5-benzylsulfanyltetrazoles substituted on the phenyl ring as well as on the benzyl moiety was evaluated for in vitro antimycobacterial activity against Mycobacterium avium and two strains of M. kansasii. We tried to use the Hansch approach, the Free-Wilson approach and their combination for structure-activity correlation but the calculations were statistically insignificant.

Substrate binding changes conformation of the alpha-, but not the beta-subunit of mitochondrial processing peptidase.

Lifetime analysis of tryptophan fluorescence of the mitochondrial processing peptidase (MPP) from Saccharomyces cerevisiae clearly proved that substrate binding evoked a conformational change of the alpha-subunit while presence of substrate influenced neither the lifetime components nor the average lifetime of the tryptophan excited state of the beta-MPP subunit. Interestingly, lifetime analysis of tryptophan fluorescence decay of the alpha-MPP subunit revealed about 11% of steady-state fractional intensity due to the long-lived lifetime component, indicating that at least one tryptophan residue is partly buried at the hydrophobic microenvironment. Computer modeling, however, predicted none of three tryptophans, which the alpha-subunit contains, as deeply buried in the protein matrix. We conclude this as a consequence of a possible dimeric (oligomeric) structure.

Two-step processing of human frataxin by mitochondrial processing peptidase. Precursor and intermediate forms are cleaved at different rates.

We showed previously that maturation of the human frataxin precursor (p-fxn) involves two cleavages by the mitochondrial processing peptidase (MPP). This observation was not confirmed by another group, however, who reported only one cleavage. Here, we demonstrate conclusively that MPP cleaves p-fxn in two sequential steps, yielding a 18,826-Da intermediate (i-fxn) and a 17,255-Da mature (m-fxn) form, the latter corresponding to endogenous frataxin in human tissues. The two cleavages occur between residues 41-42 and 55-56, and both match the MPP consensus sequence RX downward arrow (X/S). Recombinant rat and yeast MPP catalyze the p --> i step 4 and 40 times faster, respectively, than the i --> m step. In isolated rat mitochondria, p-fxn undergoes a sequence of cleavages, p --> i --> m --> d(1) --> d(2), with d(1) and d(2) representing two C-terminal fragments of m-fxn produced by an unknown protease. The i --> m step is limiting, and the overall rate of p --> i --> m does not exceed the rate of m --> d(1) --> d(2), such that the levels of m-fxn do not change during incubations as long as 3 h. Inhibition of the i --> m step by a disease-causing frataxin mutation (W173G) leads to nonspecific degradation of i-fxn. Thus, the second of the two processing steps catalyzed by MPP limits the levels of mature frataxin within mitochondria.

Iron-dependent self-assembly of recombinant yeast frataxin: implications for Friedreich ataxia.

Frataxin deficiency is the primary cause of Friedreich ataxia (FRDA), an autosomal recessive cardiodegenerative and neurodegenerative disease. Frataxin is a nuclear-encoded mitochondrial protein that is widely conserved among eukaryotes. Genetic inactivation of the yeast frataxin homologue (Yfh1p) results in mitochondrial iron accumulation and hypersensitivity to oxidative stress. Increased iron deposition and evidence of oxidative damage have also been observed in cardiac tissue and cultured fibroblasts from patients with FRDA. These findings indicate that frataxin is essential for mitochondrial iron homeostasis and protection from iron-induced formation of free radicals. The functional mechanism of frataxin, however, is still unknown. We have expressed the mature form of Yfh1p (mYfh1p) in Escherichia coli and have analyzed its function in vitro. Isolated mYfh1p is a soluble monomer (13,783 Da) that contains no iron and shows no significant tendency to self-associate. Aerobic addition of ferrous iron to mYfh1p results in assembly of regular spherical multimers with a molecular mass of approximately 1. 1 MDa (megadaltons) and a diameter of 13+/-2 nm. Each multimer consists of approximately 60 subunits and can sequester >3,000 atoms of iron. Titration of mYfh1p with increasing iron concentrations supports a stepwise mechanism of multimer assembly. Sequential addition of an iron chelator and a reducing agent results in quantitative iron release with concomitant disassembly of the multimer, indicating that mYfh1p sequesters iron in an available form. In yeast mitochondria, native mYfh1p exists as monomer and a higher-order species with a molecular weight >600,000. After addition of (55)Fe to the medium, immunoprecipitates of this species contain >16 atoms of (55)Fe per molecule of mYfh1p. We propose that iron-dependent self-assembly of recombinant mYfh1p reflects a physiological role for frataxin in mitochondrial iron sequestration and bioavailability.

PCR method for generating multiple mutations at adjacent sites.

Procedures to introduce point mutations, restriction sites and insert or delete DNA fragments are very important tools to study protein function. We describe here two-step PCR-based method for generating single or multiple mutations, insertions and deletions in a small region of the sequence. In the first step, a unique restriction site is introduced near the part of DNA sequence to be changed, without changing the amino acid sequence. For this step, one of the methods already described can be used. In the second step, mutations are introduced using mutagenic primers containing the unique restriction site from the first step at the 5' end, paired with a universal primer crossing another unique restriction site present originally in the sequence. The method is very simple, economic and rapid. In comparison with the traditional in vitro mutagenesis methods, one can generate large numbers of mutated plasmids in hours.

Complementation between mitochondrial processing peptidase (MPP) subunits from different species.

Mitochondrial processing peptidase (MPP), a dimer of nonidentical subunits, is the primary peptidase responsible for the removal of leader peptides from nuclearly encoded mitochondrial proteins. Alignments of the alpha and beta subunits of MPP (alpha- and beta-MPP) from different species show strong protein sequence similarity in certain regions, including a highly negatively charged region as well as a domain containing a putative metal ion binding site. In this report, we describe experiments in which we combine the subunits of MPP from yeast, rat, and Neurospora crassa, both in vivo and in vitro and mesure the resultant processing activity. For in vivo complementation, we used the temperature sensitive mif1 and mif2 yeast mutants, which lack MPP activity at the nonpermissive temperature (37 degrees C). We found that the defective alpha-MPP of mif2 cannot be substituted for by the alpha-MPP from rat or Neurospora. On the other hand, the beta-MPP from rat and Neurospora can fully substitute for the defective beta-MPP in the mif1 mutant. These results were confirmed in in vitro experiments in which individually expressed subunits were combined. Only combinations of the alpha-MPP from yeast with the beta-MPP from rat or Neurospora produced active MPP.

Yeast and human frataxin are processed to mature form in two sequential steps by the mitochondrial processing peptidase.

Frataxin is a nuclear-encoded mitochondrial protein which is deficient in Friedreich's ataxia, a hereditary neurodegenerative disease. Yeast mutants lacking the yeast frataxin homologue (Yfh1p) show iron accumulation in mitochondria and increased sensitivity to oxidative stress, suggesting that frataxin plays a critical role in mitochondrial iron homeostasis and free radical toxicity. Both Yfh1p and frataxin are synthesized as larger precursor molecules that, upon import into mitochondria, are subject to two proteolytic cleavages, yielding an intermediate and a mature size form. A recent study found that recombinant rat mitochondrial processing peptidase (MPP) cleaves the mouse frataxin precursor to the intermediate but not the mature form (Koutnikova, H., Campuzano, V., and Koenig, M. (1998) Hum. Mol. Gen. 7, 1485-1489), suggesting that a different peptidase might be required for production of mature size frataxin. However, in the present study we show that MPP is solely responsible for maturation of yeast and human frataxin. MPP first cleaves the precursor to intermediate form and subsequently converts the intermediate to mature size protein. In this way, MPP could influence frataxin function and indirectly affect mitochondrial iron homeostasis.