Cutaneous features of pseudoxanthoma elasticum in a patient with generalized arterial calcification of infancy due to a homozygous missense mutation in the ENPP1 gene.

BACKGROUND: Pseudoxanthoma elasticum (PXE) manifests with cutaneous lesions consisting of yellowish papules coalescing into plaques of inelastic skin. Histopathology demonstrates accumulation of pleiomorphic elastic structures with progressive mineralization. The classic form of PXE is caused by mutations in the ABCC6 gene. OBJECTIVES: A 2-year-old patient with PXE of the neck, inguinal folds and lower abdomen, and with extensive tissue mineralization, was evaluated for the underlying mutations in candidate genes known to be involved in ectopic mineralization disorders. METHODS: The patient's genotype was studied by sequencing ABCC6, MGP and ENPP1 genes, encoding proteins which harbour mutations in ectopic mineralization disorders. RESULTS: No pathogenetic mutations were found in the ABCC6 or MGP genes. Sequencing of ENPP1 disclosed a homozygous missense mutation, p.Y513C, associated with generalized arterial calcification of infancy. CONCLUSIONS: This study demonstrates the presence of the cutaneous features of PXE in a genetically distinct disease, generalized arterial calcification of infancy, and thus expands the spectrum of PXE-related disorders.

Raman spectroscopy-compatible inactivation method for pathogenic endospores.

Micro-Raman spectroscopy is a fast and sensitive tool for the detection, classification, and identification of biological organisms. The vibrational spectrum inherently serves as a fingerprint of the biochemical composition of each bacterium and thus makes identification at the species level, or even the subspecies level, possible. Therefore, microorganisms in areas susceptible to bacterial contamination, e.g., clinical environments or food-processing technology, can be sensed. Within the scope of point-of-care-testing also, detection of intentionally released biosafety level 3 (BSL-3) agents, such as Bacillus anthracis endospores, or their products is attainable. However, no Raman spectroscopy-compatible inactivation method for the notoriously resistant Bacillus endospores has been elaborated so far. In this work we present an inactivation protocol for endospores that permits, on the one hand, sufficient microbial inactivation and, on the other hand, the recording of Raman spectroscopic signatures of single endospores, making species-specific identification by means of highly sophisticated chemometrical methods possible. Several physical and chemical inactivation methods were assessed, and eventually treatment with 20% formaldehyde proved to be superior to the other methods in terms of sporicidal capacity and information conservation in the Raman spectra. The latter fact has been verified by successfully using self-learning machines (such as support vector machines or artificial neural networks) to identify inactivated B. anthracis-related endospores with adequate accuracies within the range of the limited model database employed.

Effects of factor XI deficiency on ferric chloride-induced vena cava thrombosis in mice.

BACKGROUND: Increased plasma levels of coagulation factor (F) XI are a risk factor for venous thrombosis. OBJECTIVE: To further explore the relationship between FXI and venous thrombosis, we evaluated FXI-deficient and wild-type mice in a ferric chloride (FeCl(3))-induced vena cava thrombosis model. METHODS AND RESULTS: Thrombosis was induced by 3-min topical application of filter papers containing increasing concentrations of FeCl(3) and the thrombus was measured at 30 min. In contrast to wild-type mice, FXI-deficient mice failed to form a thrombus with 5% FeCl(3,) and were partially protected against 7.5% and 10% FeCl(3,) respectively. The protective effect was substantially stronger than a high dose of heparin (1,000 units kg(-1), i.v.), clopidogrel (30 mg kg(-1), p.o.) or argatroban (30 mg kg(-1), i.p.). These antithrombotic agents resulted in off-scale bleeding in a tail bleeding time assay, whereas the bleeding time of FXI-deficient mice was unchanged compared to wild-type mice. In addition to its known effect on the coagulation cascade, enhanced clot lysis was demonstrated in FXI-deficient mouse and human plasma compared to those supplemented with FXIa. CONCLUSION: Given the strong antithrombotic efficacy (possibly contributed by strong anticoagulant activity associated with increased fibrinolytic activity) and mild bleeding diathesis associated with FXI deficiency, therapeutic inhibition of FXI may be a reasonable therapeutic strategy to treat or prevent venous thrombosis.

Murine model of ferric chloride-induced vena cava thrombosis: evidence for effect of potato carboxypeptidase inhibitor.

BACKGROUND/OBJECTIVE: Thrombin-activatable fibrinolysis inhibitor (TAFI) is a plasma carboxypeptidase that renders a fibrin-containing thrombus less sensitive to lysis. In the present study, we describe the development of a murine model of vena cava thrombosis and its use to characterize the antithrombotic activity of potato carboxypeptidase inhibitor (PCI) of TAFIa (activated TAFI) in mice. METHODS/RESULTS: Vena cava thrombosis was induced by various concentrations of FeCl(3) in C57BL/6 mice. A relatively mild stimulus (3.5% FeCl(3)) induced thrombosis that was consistent and sensitive to reference antithrombotic agents such as clopidogrel and heparin. Dose-response studies identified a PCI dose (5 mg kg(-1) bolus plus 5 mg kg(-1) h(-1), i.v.) that produced a maximum 45% decrease in vena cava thrombus mass as assessed by protein content (n = 8, P < 0.01 compared to vehicle) in the 3.5% FeCl(3)-induced model without exogenous tissue plasminogen activator administration. In contrast, PCI had no effect on 3.5% FeCl(3)-induced carotid artery thrombosis in mice. In a tail transection bleeding model, the 5 mg kg(-1) bolus plus 5 mg kg(-1) h(-1) dose of PCI increased tail-bleeding time up to 3.5 times control (n = 8, P < 0.05). The ex vivo activity of antithrombotic doses of PCI was also demonstrated by the enhanced lysis of whole blood clots formed in a thrombelastograph with the addition of a sub-threshold concentration of tPA. CONCLUSION: These studies provide evidence for a role of TAFIa in venous thrombosis in mice, and describe an optimized vena cava injury model appropriate for the evaluation of antithrombotic drugs and the characterization of novel therapeutic targets.

Effects of factor IX or factor XI deficiency on ferric chloride-induced carotid artery occlusion in mice.

Factor XI (FXI) and factor IX (FIX) are zymogens of plasma serine proteases required for normal hemostasis. The purpose of this work was to evaluate FXI and FIX as potential therapeutic targets by means of a refined ferric chloride (FeCl(3))-induced arterial injury model in factor-deficient mice. Various concentrations of FeCl(3) were used to establish the arterial thrombosis model in C57BL/6 mice. Carotid artery blood flow was completely blocked within 10 min in C57BL/6 mice by application of 3.5% FeCl(3). In contrast, FXI- and FIX-deficient mice were fully protected from occlusion induced by 5% FeCl(3), and were partially protected against the effect of 7.5% FeCl(3). The protective effect was comparable to very high doses of heparin (1000 units kg(-1)) and substantially more effective than aspirin. While FXI and FIX deficiencies were indistinguishable in the carotid artery injury model, there was a marked difference in a tail-bleeding-time assay. FXI-deficient and wild-type mice have similar bleeding times, while FIX deficiency was associated with severely prolonged bleeding times (>5.8-fold increase, P < 0.01). Given the relatively mild bleeding diathesis associated with FXI deficiency, therapeutic inhibition of FXI may be a reasonable strategy for treating or preventing thrombus formation.

Retro-binding thrombin active site inhibitors: identification of an orally active inhibitor of thrombin catalytic activity.

A series of retro-binding inhibitors of human alpha-thrombin was prepared to elucidate structure-activity relationships (SAR) and optimize in vivo performance. Compounds 9 and 11, orally active inhibitors of thrombin catalytic activity, were identified to be efficacious in a thrombin-induced lethality model in mice.

[Poly-beta-hydroxybutyric acid (PHB) films and plates in defect covering of the osseus skull in a rabbit model]. / Polyhydroxybuttersäure (PHB)-Folien und -Platten zur Defektdeckung des knöchernen Schädels im Kaninchenmodell.

BACKGROUND: Titan plates have proven a success in the operative assistance of middle face fractures for stabile osteosynthesis. Also bioresorbant materials are being used increasingly. METHOD: Films and plates made from poly-beta-hydroxybutyric acid (PHB) with two holes and bolts are tested subperiostally on the osseus skull of 15 rabbits or respectively on cut trough zygomatic arches. The test bodies and the surrounding tissue are explantated after a defined period and are clinically and histologically prepared. RESULTS: All implants healed well. There were no macroscopic or microscopic signs of inflammation. A very slow, clinically not recordable decomposition followed. A "leap" in the decomposition evidently took place between the 20th and 25th month. Only initial signs of resorbation were to be found microfocally on the surface of the implant until 20 months after implantation but no more test body could be detected after 25 months. CONCLUSION: PHB is suitable for defect covery of the osseus skull or respectively as osteosynthesis material for fractures of the visceral cranium.

Bacterial cytochrome c nitrite reductase: new structural and functional aspects.

Cytochrome c nitrite reductase catalyzes the six-electron reduction of nitrite to ammonia as a key step within the biological nitrogen cycle. Most recently, the crystal structure of the soluble enzyme from Sulfurospirillum deleyianum could be solved to 1.9 A resolution. This set the basis for new experiments on structural and functional aspects of the pentaheme protein which carries a Ca(2+) ion close to the active site heme. In the crystal, the protein was a homodimer with ten hemes in very close packing. The strong interaction between the nitrite reductase monomers also occurred in solution according to the dependence of the activity on the protein concentration. Addition of Ca(2+) to the enzyme as isolated had a stimulating effect on the activity. Ca(2+) could be removed from the enzyme by treatment with chelating agents such as EGTA or EDTA which led to a decrease in activity. In addition to nitrite, the enzyme converted NO, hydroxylamine and O-methyl hydroxylamine to ammonia at considerable rates. With N2O the activity was much lower; most likely dinitrogen was the product in this case. Cytochrome c nitrite reductase exhibited a remarkably high sulfite reductase activity, with hydrogen sulfide as the product. A paramagnetic Fe(II)-NO, S = 1/2 adduct was identified by rapid freeze EPR spectroscopy under turnover conditions with nitrite. This potential reaction intermediate of the reduction of nitrite to ammonia was also observed with PAPA NONOate and Spermine NONOate.

Methods for improving emergency department operational process.

It's not just the pain or injury that gives patients a natural aversion to visiting the emergency department, but the ED's entire operational process. William Schumacher, M.D., a board-certified emergency medical physician, writes about ways to improve efficiency and make the ED experience more agreeable.

[Variations in the course of the internal carotid artery: possible risks in so-called standard operations in the area of the pharynx]. / Verlaufsvarianten der Arteria carotis interna: Mögliche Risiken bei sogenannten Standardoperationen im Pharynxbereich.

BACKGROUND: Many abnormalities in the course of the major vessels of the head and neck have been described. Special care must be taken in case of deviation of the internal carotid artery bulging the pharyngeal wall. PATIENTS: In two cases we demonstrate internal carotid arteries partially running underneath the posterior pharyngeal wall. RESULTS: Those variations are often asymptomatic, only requiring surgical treatment when causing neurologic complaints. On the other hand, they may be very dangerous, if operations in the upper pharynx are carried out. CONCLUSIONS: The surgeon (in special the younger surgeon) must be well-informed about potential vascular abnormalities, before performing "routine-operations" (tonsillectomies, adenotomies) in the upper pharynx.

Dehalobacter restrictus gen. nov. and sp. nov., a strictly anaerobic bacterium that reductively dechlorinates tetra- and trichloroethene in an anaerobic respiration.

The highly enriched anaerobic bacterium that couples the reductive dechlorination of tetrachloroethene to growth, previously referred to as PER-K23, was obtained in pure culture and characterized. The bacterium, which does not form spores, is a small, gram-negative rod with one lateral flagellum. It utilized only H2 as an electron donor and tetrachloroethene and trichloroethene as electron acceptors in an anaerobic respiration process; it could not grow fermentatively. Acetate served as a carbon source in a defined medium containing iron as the sole trace element, the two vitamins thiamine and cyanocobalamin, and the three amino acids arginine, histidine, and threonine. The cells contained menaquinones and b-type cytochromes. The G+C content of the DNA was 45.3 +/- 0.3 mol%. The cell wall consisted of type-A3gamma peptidoglycan with ll-diaminopimelic acid and one glycine as an interpeptide bridge. The cells are surrounded by an S-layer; an outer membrane was absent. Comparative sequence analysis of the 16S rRNA sequence showed that PER-K23 is related to gram-positive bacteria with a low G+C content of the DNA. Based on the cytological, physiological, and phylogenetic characterization, it is proposed to affiliate the isolate to a new genus, Dehalobacter, with PER-K23 as the type strain of the new species Dehalobacter restrictus.

[An unusual injury pattern in magically increased false sex crime]. / Ungewöhnliches Verletzungsmuster bei magisch überhöhtem unechtem Triebdelikt.

Case report on a rape-homicide by manual strangulation involving a 59 year old female. The autopsy disclosed a peculiar cross-shaped superficial incised wound of the abdomen, encircled by 12 stab-wounds, furthermore multiple superficial and deep incised wounds of the genitalia. The injury pattern was in good agreement with the psychiatric interpretation of the sexual behaviour as outlet of severe aggressive impulses originating from non-sexual motives.

Contaminated environments in the subsurface and bioremediation: organic contaminants.

Due to leakages, spills, improper disposal and accidents during transport, organic compounds have become subsurface contaminants that threaten important drinking water resources. One strategy to remediate such polluted subsurface environments is to make use of the degradative capacity of bacteria. It is often sufficient to supply the subsurface with nutrients such as nitrogen and phosphorus, and aerobic treatments are still dominating. However, anaerobic processes have advantages such as low biomass production and good electron acceptor availability, and they are sometimes the only possible solution. This review will focus on three important groups of environmental organic contaminants: hydrocarbons, chlorinated and nitroaromatic compounds. Whereas hydrocarbons are oxidized and completely mineralized under anaerobic conditions in the presence of electron acceptors such as nitrate, iron, sulfate and carbon dioxide, chlorinated and nitroaromatic compounds are reductively transformed. For the aerobic often persistent polychlorinated compounds, reductive dechlorination leads to harmless products or to compounds that are aerobically degradable. The nitroaromatic compounds are first reductively transformed to the corresponding amines and can subsequently be bound to the humic fraction in an aerobic process. Such new findings and developments give hope that in the near future contaminated aquifers can efficiently be remediated, a prerequisite for a sustainable use of the precious-subsurface drinking water resources.

Redox chemistry of cobalamin and iron-sulfur cofactors in the tetrachloroethene reductase of Dehalobacter restrictus.

Respiration of Dehalobacter restrictus is based on reductive dechlorination of tetrachloroethene. The terminal component of the respiratory chain is the membrane-bound tetrachloroethene reductase. The metal prosthetic groups of the purified enzyme have been studied by optical and EPR spectroscopy. The 60-kDa monomer contains one cobalamin with Em(Co[1+/2+]) = -350 mV and Em(Co[2+/3+]) > 150 mV and two electron-transferring [4Fe-4S](2+;1+) clusters with rather low redox potentials of Em approximately -480 mV. The cob(II)alamin is present in the base-off configuration. A completely reduced enzyme sample reacted very rapidly with tetrachloroethene yielding base-off cob(II)alamin rather than trichlorovinyl-cob(III)alamin.

Nutritional intake of 2868 IDDM patients from 30 centres in Europe. EURODIAB IDDM Complications Study Group.

The EURODIAB IDDM Complications Study, a cross-sectional, clinic-based study, was designed to measure the prevalence of diabetic complications in stratified samples of European insulin-dependent diabetic (IDDM) patients. As diet may be related to diabetic complications, nutritional intake was analysed in the study population. The aims of this first nutritional paper are to describe the nutrient intake in 2868 IDDM patients from 30 centres in 16 countries throughout Europe, to investigate the degree of regional differences in nutrient intake and to compare current intakes with recommended levels. Nutritional intake from 1458 male and 1410 female IDDM patients was assessed by a validated 3-day record (two weekdays, Sunday) and centrally analysed. Mean energy intake for all patients was 2390 +/- 707 kcal/day. Mean protein intake was 1.5 +/- 0.5 g/kg body weight. Carbohydrate intake was 43% and fibre intake 18 g/day. Alcohol intake for the total cohort was 2% of energy. Total fat contributed 38% of energy, with 14% from saturated fat. The Italian centres reported lower total and saturated fat intakes compared with other centres. Recommendations from the Diabetes and Nutrition Study Group of the EASD for total fat, saturated fatty acids and carbohydrate were only achieved by 14%, 14% and 15% of patients, respectively. The data of the present study clearly indicate current problems in the nutritional intake of European IDDM patients. These findings contribute to the definition of future targets in the nutritional management of IDDM patients, to be achieved as part of the initiatives taken by the St. Vincent Declaration action programme.

Low-molecular-weight heparin (fragmin) and thrombin active-site inhibitor (argatroban) compared in experimental arterial and venous thrombosis and bleeding time.

The antithrombotic and bleeding effects of a low-molecular-weight heparin (LMWH, fragmin) and a thrombin active-site inhibitor (argatroban) were determined in anesthetized rats. Occlusive thrombi were produced in the vena cava, either by partial stasis of blood flow or transmural vessel injury, and in the carotid artery by transmural vessel injury. Bleeding time was measured by puncturing small mesenteric arteries. Each drug was tested in multiple intravenous (i.v.) doses and inhibited venous and arterial thrombosis when the activated partial thromboplastin time (APTT) was increased as much as or more than twofold, although greater APTT increases were required with fragmin and against arterial thrombosis. Fragmin and argatroban decreased to an equivalent extent the weight of venous thrombi induced by stasis (> or = 99%) or vessel injury (90 and 96%, respectively). The maximum inhibition of arterial thrombosis was less with fragmin (69%) and argatroban (65%) and required higher doses of each drug relative to venous thrombosis. At doses that were just optimal against arterial thrombosis, bleeding time was increased moderately by fragmin (32%) and was unaffected by argatroban. These studies demonstrate that doses of fragmin and argatroban that exert comparable antithrombotic activity in large arteries and veins have only moderate effects on bleeding time in small arteries.

The proton/electron ration of the menaquinone-dependent electron transport from dihydrogen to tetrachloroethene in "Dehalobacter restrictus".

In the anaerobic respiration chain of "Dehalobacter restrictus," dihydrogen functioned as the electron donor and tetrachloroethene (PCE) functioned as the electron acceptor. The hydrogenase faced the periplasm, and the PCE reductase faced the cytoplasmic side of the membrane. Both activities were associated with the cytoplasmic membrane. UV spectroscopy showed that membrane-bound menaquinone (MQ) was reduced by oxidation of H2 and reoxidized by reduction of PCE, indicating that MQ functions as an electron mediator. Fast proton liberation (t1/2 = 6 +/- 2 s) during electron transport from H2 to PCE and to trichloroethene (TCE) after addition of either PCE or TCE to H2-saturated cells resulted in an extrapolated H+/e- ratio of 1.25 +/- 0.2. This ratio indicated that besides the formation of protons upon oxidation of H2, vectorial translocation of protons from the inside to the outside could also occur. Proton liberation was inhibited by carbonylcyanide m-chlorophenylhydrazone (CCCP), 2-n-heptyl-4-hydroxyquinoline N-oxide (HOQNO), and CuCl2. Fast proton liberation with an H+/e- ratio of 0.65 +/- 0.1 was obtained after addition of the MQ analog 2,3-dimethyl-1,4-naphthoquinone (DMN) as an oxidant pulse. This acidification was also inhibited by CCCP, HOQNO, and CuCl2. Oxidation of reduced DMN by PCE was not associated with fast acidification. The results with DMN indicate that the consumption and release of protons associated with redox reactions of MQ during electron transfer from H2 to PCE both occurred at the cytoplasmic side of the membrane. The PCE reductase was photoreversibly inactivated by 1-iodopropane, indicating that a corrinoid was involved in the PCE reduction.

A ferret model of electrical-induction of arterial thrombosis that is sensitive to aspirin.

An experimental model of acute thrombosis was developed in pentobarbital- anesthetized ferrets. A 10-min anodal electrical stimulation of 1 mA was delivered to the external surface of the carotid artery while measuring carotid blood flow (CBF). This produced an occlusive thrombus in all vehicle-treated ferrets within 41 +/- 3 min with an average weight of 8 +/- 1 mg (n = 7). These thrombi were enriched in both platelets and fibrin and were adherent at the site of transmural vascular injury as determined by light and electron microscopy. To determine the model's sensitivity to antiplatelet drugs, aspirin or a thromboxane (TxA2) receptor antagonist (ifetroban) were administered 15 min before electrical stimulation. Thrombus weight was reduced 58% by aspirin (10 mg/kg, i.v.) and 74% by ifetroban (1 mg/kg + 1 mg/kg per hr, i.v.). Both drugs also improved CBF and decreased vascular occlusion. Ferrets were more sensitive than rats to aspirin's inhibition of collagen-induced platelet aggregation as determined ex vivo in whole blood. Separate in vitro platelet aggregation studies revealed species differences in reactivity to U-46619 (TxA2 receptor agonist) and collagen in the order of human > ferret > rat, with relatively lesser variations in ADP responses. These studies identify the ferret as a useful species for evaluating antithrombotic drugs in a model in which aspirin is efficacious.

Sensitivity of experimental venous and arterial thrombosis and bleeding to ancrod-induced defibrinogenation.

The effect of ancrod-induced defibrinogenation on thrombosis and bleeding time was determined in anesthetized rats. Functional plasma fibrinogen levels were reduced 42, 71, 94 and 93% by ancrod doses of 5, 10, 20 and 30 U/kg, respectively, while a 2.5 U/kg dose was without significant effect. Ancrod inhibited vena cava thrombosis induced by partial stasis of blood flow combined with mild vascular injury. Thrombus weight was decreased 85 and 93% by the 10 and 20 U/kg doses, but was unaffected at lower doses. In contrast, ancrod doses of up to 30 U/kg did not significantly decrease carotid artery thrombi formed in response to oxidative transmural vessel injury. Ancrod caused a dose-dependent increase in bleeding time measured by puncturing small mesenteric arteries with a hypodermic needle. The bleeding time increase was approximately 38% in response to the 2.5 and 5 U/kg doses, and 182% in response to the 10 U/kg dose. These studies demonstrate that ancrod-induced reductions in plasma fibrinogen more effectively inhibit venous compared to arterial thrombosis, although these activities require doses that also increase bleeding time in small arteries.