Density of states within the bandgap of perovskite thin films studied using the moving grating technique

In this work, we further study the moving grating technique applied to halide perovskite thin-film materials. First, we show some problems that emerge when analyzing the experimental data with the classical formulation, which does not distinguish between free and trapped carriers and hence only gives average quantities for the transport parameters. We show that using a more general framework, taking into account the multiple trapping of carriers within a density of localized states, allows for an accurate description. Since it includes the density of states (DOS) of the material, it enables the possibility to test different DOS models proposed in the past for halide perovskite thin films. We check whether these models give rise to the type of curves we have measured under different experimental conditions. Finally, we propose a new model for the DOS in the forbidden gap, which results in the best fit found for the measurements performed. This allows us to give ranges of values for the parameters that define the DOS, which, as far as we know, are given for the first time.

Fixed-dose, Body Weight-independent Subcutaneous LMW Heparin versus Adjusted Dose Unfractionated Intravenous Heparin in the Initial Treatment of Proximal Venous Thrombosis

Body weight-adjusted subcutaneous low-molecular-weight heparin (LMWH) has been proven to be at least as effective and safe as dose-adjusted intravenous unfractionated heparin (UFH) for the treatment of patients with venous thromboembolism. However, body weight-adjusted dosage of low-molecular-weight heparin may be cumbersome and could lead possibly to incorrect dosing. Therefore a fixed LMWH dose, independent of body-weight, might rationalize initial treatment for venous thromboembolism.

Patients with proven proximal deep-vein thrombosis were randomly assigned to fixed dose subcutaneous LMWH Certoparin (8,000 anti-factor Xa U b.i.d.; 265 patients) or to adjusted dose i.v. UFH (273 patients) for 12 days. Vitamin K antagonists were started between day 3 and 7 and continued for up to 6 months. The primary outcome measure was a 30 percent or greater improvement in the Marder Score, as revealed by repeated venography on day 12 (end of the initial treatment). The secondary composite outcome measure included death, recurrent venous thromboembolism and major bleeding and was assessed at day 12 and after 6 months by a blinded adjunction committee.

The Marder score improved by 30% or more in 30.3% and 25.0% of patients assigned to LMWH (198 paired venograms) and UFH (192 paired venograms), respectively (2p = 0.26). At the end of the initial treatment, the composite outcome was observed in 4 of the 265 patients (1.5%) randomized to LMWH, as compared with 14 of the 273 patients (5.1%) randomized to UFH (2p = 0.03). At 6 months these figures were 6.8% and 12.8%, respectively (risk reduction 0.53, confidence interval 0.31-0.90, 2p = 0.02).

Fixed dose subcutaneous LMWH certoparin is at least as efficacious as UFH in resolving proximal vein thrombosis. With respect to the composite outcome of death, recurrent venous thromboembolism and major bleeding LMWH treatment performed significantly better both during initial therapy and at a six-month follow-up.

Plasma concentrations and intakes of amino acids in male meat-eaters, fish-eaters, vegetarians and vegans: a cross-sectional analysis in the EPIC-Oxford cohort

BACKGROUND/OBJECTIVES

We aimed to investigate the differences in plasma concentrations and in intakes of amino acids between male meat-eaters, fish-eaters, vegetarians and vegans in the Oxford arm of the European Prospective Investigation into Cancer and Nutrition.

SUBJECTS/METHODS

This cross-sectional analysis included 392 men, aged 30-49 years. Plasma amino acid concentrations were measured with a targeted metabolomic approach using mass spectrometry, and dietary intake was assessed using a food frequency questionnaire. Differences between diet groups in mean plasma concentrations and intakes of amino acids were examined using analysis of variance, controlling for potential confounding factors and multiple testing.

RESULTS

In plasma, concentrations of 6 out of 21 amino acids varied significantly by diet group, with differences of -13% to +16% between meat-eaters and vegans. Concentrations of methionine, tryptophan and tyrosine were highest in fish-eaters and vegetarians, followed by meat-eaters, and lowest in vegans. A broadly similar pattern was seen for lysine, whereas alanine concentration was highest in fish-eaters and lowest in meat-eaters. For glycine, vegans had the highest concentration and meat-eaters the lowest. Intakes of all 18 dietary amino acids differed by diet group; for the majority of these, intake was highest in meat-eaters followed by fish-eaters, then vegetarians and lowest in vegans (up to 47% lower than in meat-eaters).

CONCLUSIONS

Men belonging to different habitual diet groups have significantly different plasma concentrations of lysine, methionine, tryptophan, alanine, glycine and tyrosine. However, the differences in plasma concentrations were less marked than and did not necessarily mirror those seen for amino acid intakes.

Baseline patterns of adipose tissue fatty acids and long-term risk of breast cancer: a case-cohort study in the Danish cohort Diet, Cancer and Health

BACKGROUND/OBJECTIVES

The evidence regarding fatty acids and breast cancer risk is inconclusive. Adipose tissue fatty acids can be used as biomarkers of fatty acid intake and of endogenous fatty acid exposure. Fatty acids in adipose tissue are correlated owing to common dietary sources and shared metabolic pathways, which group fatty acids into naturally occurring patterns. We aimed to prospectively investigate associations between adipose tissue fatty acid patterns and long-term risk of total breast cancer and breast cancer subtypes characterised by oestrogen and progesterone receptor status (ER and PR).

SUBJECTS/METHODS

This case-cohort study was based on data from the Danish cohort Diet, Cancer and Health. At baseline, a fat biopsy and information on lifestyle and reproductive factors were collected. From the 31 original fatty acids measured, patterns of fatty acids were identified using the treelet transform. During a median follow-up of 5.3 years, 474 breast cancer cases were identified. Hazard ratios and 95% confidence intervals of risk of total breast cancer and of subtypes according to quintiles of factor score were determined by weighted Cox proportional hazards regression.

RESULTS

After adjustment for potential confounders, factor scores for the seven patterns identified by the treelet transform were not associated with risk of total breast cancer, nor with risk of ER+, ER-, PR+ or PR- tumours.

CONCLUSIONS

No clear associations between the patterns of fatty acids at baseline and long-term risk of total breast cancer or ER+, ER-, PR+ or PR- tumours were observed.

Biochemical and pharmacological characterization of AZD1981, an orally available selective DP2 antagonist in clinical development for asthma

BACKGROUND AND PURPOSE

The discovery of DP2 as a second receptor for PGD2 has prompted the search for antagonists as potential novel therapies based on the associations between PGD2 and disease. Here we describe the biochemical and pharmacological properties of 4-(acetylamino)-3-[(4-chlorophenyl)thio]-2-methyl-1H-indole-1-acetic acid (AZD1981), a novel DP2 receptor antagonist.

EXPERIMENTAL APPROACH

Binding to DP2 , functional receptor pharmacology and selectivity were studied in both human and animal systems.

KEY RESULTS

AZD1981 displaced radio-labelled PGD2 from human recombinant DP2 with high potency (pIC50 = 8.4). Binding was reversible, non-competitive and highly selective against a panel of more than 340 other enzymes and receptors, including DP1 (>1000-fold selective). AZD1981 inhibited DP2 -mediated shape change and CD11b up-regulation in human eosinophils, shape change in basophils and chemotaxis of human eosinophils and Th2 cells with similar potency. AZD1981 exhibited good cross-species binding activity against mouse, rat, guinea pig, rabbit and dog DP2 . Evaluation in mouse, rat or rabbit cell systems was not possible as they did not respond to DP2 agonists. Agonist responses were seen in guinea pig and dog, and AZD1981 blocked DP2 -mediated eosinophil shape change. Such responses were more robust in the guinea pig, where AZD1981 also blocked DP2 -dependent eosinophil emigration from bone marrow.

CONCLUSIONS AND IMPLICATIONS

AZD1981 is a DP2 antagonist that blocks functional responses in eosinophils, Th2 cells and basophils. It exhibited similar potency irrespective of the cell type, DP2 agonist or species used. This selective orally active agent is currently under clinical evaluation as a potential therapeutic agent in respiratory diseases including asthma.

Lentiviral modification of enriched populations of bovine male gonocytes

Undifferentiated germ cells have the capacity to develop into sperm capable of fertilizing oocytes and contributing genetic material to subsequent generations. The most primitive prepubertal undifferentiated germ cells include gonocytes and undifferentiated spermatogonia, including spermatogonial stem cells (SSC). Gonocytes, present in the testis at birth, differentiate into SSC, which maintain spermatogenesis for the remainder of the male's life. Because of their capacity to contribute to lifelong spermatogenesis, undifferentiated germ cells are attractive targets for genetic modification to produce transgenic animals, including cattle. To maximize the efficiency of genetic modification of bovine gonocytes and SSC, effective enrichment techniques need to be developed. Selection of bovine gonocytes using differential plating was improved 8-fold (P < 0.001) when using a combination of extracellular matrix proteins, including laminin, fibronectin, collagen type IV, and gelatin, compared to using laminin and gelatin alone. Selected cells labeled with PKH26 formed colonies of donor-derived germ cells after transplantation into recipient mouse testes, indicating putative stem cell function. Significantly more colonies (P < 0.001) per 1 × 10(5) viable transplanted cells were formed from isolated nonadherent cells (203 ± 23.2) compared to adherent (20 ± 2.7) or Percoll (45.5 ± 4.5) selected cells. After selection, some gonocytes were transduced using a lentiviral vector containing the transgene for the enhanced green fluorescent protein. Transduction efficiency was 17%. Collectively, these data demonstrate effective methods for the selection and genetic modification of bovine undifferentiated germ cells.

Endocrine regulation of the establishment of spermatogenesis in pigs

Somatic and germ cell maturation precedes the start of spermatogenesis and is coordinated, so efficient spermatogenesis will occur in the adults. The present study was conducted to evaluate endocrine regulation of germ and somatic cell homeostasis in the neonatal boar testis associated with the establishment of spermatogenesis. Testis tissue obtained from 3-, 5-, 7- and 14-day-old piglets were ectopically xenografted onto castrated, immunodeficient nude mice. Grafts were removed 22 weeks later and evaluated for growth and the establishment of spermatogenesis. Recipient mouse testosterone biosynthesis and follicle-stimulating hormone (FSH) concentrations were also assayed. Testis tissue graft growth was significantly greater in testis grafts from 3-day donor tissue when compared to all other ages; 5-, 7- and 14-day-old donor tissue weights were not significantly different at removal. Follicle-stimulating hormone concentrations in recipient mice supporting testis grafts from 5-, 7- and 14-day-old donor tissues did not differ and were similar to normal physiological levels in age-matched, intact nude mice. Serum FSH levels were significantly lower in recipient mice supporting testis grafts from 3-day-old donor tissue. Radioimmunoassay and biological assay indicated no differences in testosterone production by testis tissue grafts of varying donor age. Porcine testis tissue obtained from 3-, 5-, 7- and 14-day-old neonatal boars were all capable of producing round and elongate spermatids after 22 weeks of grafting, but testis grafts from 14-day-old donors had a significantly greater (eightfold) percentage of seminiferous tubules with spermatids compared to all other donor ages (p < 0.05). Cryopreservation did not affect the ability of testis tissue grafts to grow, produce testosterone or establish spermatogenesis when compared to controls (p < 0.05). Collectively, these data demonstrate intrinsic differences in the biological activity of germ and somatic cell populations during neonatal boar testis development associated with the establishment of spermatogenesis.

A novel antagonist of prostaglandin D2 blocks the locomotion of eosinophils and basophils

BACKGROUND

Chemoattractant receptor homologous molecule of Th2 cells (CRTH2) has been shown to mediate the chemotaxis of eosinophils, basophils and Th2-type T lymphocytes. The major mast cell product prostaglandin (PG) D(2) is considered to be the principal ligand of CRTH2.

MATERIALS AND METHODS

We developed a novel CRTH2 antagonist, AZ11665362 [2,5-dimethyl-3-(8-methylquinolin-4-yl)-1H-indole-1-yl]acetic acid, and characterized its efficacy in binding assay in HEK293 cells, eosinophil and basophil shape change assay and migration assay, platelet aggregation and eosinophil release from guinea pig bone marrow. The effects were compared with ramatroban, the sole CRTH2 antagonist clinically available to date.

RESULTS

AZ11665362 bound with high affinity to human and guinea pig CRTH2 expressed in HEK293 cells and antagonized eosinophil and basophil shape change responses to PGD(2). AZ11665362 was without effect on the PGD(2)-induced inhibition of platelet aggregation. In contrast, AZ11665362 effectively inhibited the in vitro migration of human eosinophils and basophils towards PGD(2). The release of eosinophils from the isolated perfused hind limb of the guinea pig was potently stimulated by PGD(2), and this effect was prevented by AZ11665362. In all assays tested, AZ11665362 was at least 10 times more potent than ramatroban.

CONCLUSIONS

AZ11665362 is a potent CRTH2 antagonist that is capable of blocking the migration of eosinophils and basophils, and the rapid mobilization of eosinophils from bone marrow. AZ11665362 might hence be useful for the treatment of allergic diseases.

Characterization of Aspergillus oryzae fermentation extract effects on the rumen fungus Neocallimastix frontalis, EB 188. Part 2. Carbon source utilization and effects on zoospore production

The effect of a commercial Aspergillus oryzae fermentation extract on the utilization of carbon source and zoospore production by the rumen fungus Neocallimastix frontalis EB 188 was determined. In addition, the composition of a soluble extract prepared from the commercial product was analyzed. This extract was added to N. frontalis EB 188 cultures grown on a variety of substrates and periodically assayed for protein, enzymes, zoospore production, and carbon source utilization. The powdered product contained 93% dry matter, more than 3,000 A. oryzaespores per gram, and did not contain strong buffers or high concentrations of salt. Measurable concentrations of DNA, protein, carbohydrate and several enzymes including cellulase and amylase were also found. Soluble extract increased fungal physiology and treated cultures produced significantly higher levels of supernatant protein and enzymes including amylase, cellulase and beta-glucosidase. The fungal response depended on culture carbon source. However, culture zoospore production was increased regardless of substrate provided. Culture utilization of glucose was more rapid in treated cultures, yet high levels of the extract greatly inhibited glucose utilization.

Characterization of Aspergillus oryzae fermentation extract effects on the rumen fungus Neocallimastix frontalis, EB 188. Part 1. Zoospore development and physiology

Experiments were performed to determine the effect of Aspergillus oryzae (AO) fermentation extract on zoospore development in the rumen fungus Neocallimastix frontalis EB 188. Powdered product, or liquid extract prepared from such powder, was added at the recommended value for supplementation in dairy cattle. Stationary and stirred cultures were periodically sampled and assayed for extracellular and intracellular protein and enzymes, gas production, zoospore production and maturation, and carbon source utilization. Soluble extract increased fungal physiology when grown in stirred vessels or stationary cultures. Treated cultures produced higher levels of enzymes (nearly double). Mobile zoospores matured into germination entities more rapidly in treated cultures, and when powdered product was used, nearly 3 times more motile zoospores were produced at 56 h of fungal growth. Levels of the intracellular enzyme malate dehydrogenase increased by 6-fold in the presence of powdered product. Product wheat bran carrier used as soluble extract or powder had very little effect on fungal cultures. Medium cellulose was completely hydrolyzed in all cultures but this occurred earlier in those containing AO treatment.

Measuring the elastic properties of fine wire

The elastic moduli of fine wires made from MP35N and 304SS used in implantable biomedical devices are assumed to be the same as those published in the literature. However, the cold working required to manufacture the wire significantly alters the elastic moduli of the material. We describe three experiments performed on fine wire made from MP35N and 304SS. The experimentally determined Young's and shear modulus of both wire types were significantly less than the moduli reported in the literature. Young's modulus differed by as much as 26%, and the shear modulus differed by as much as 14% from reported values.

Older people with impaired mobility have specific loci of periventricular abnormality on MRI

BACKGROUND

Recent investigations using MRI suggest that older persons with mobility impairment have a greater volume of abnormal cerebral white matter compared with persons with normal mobility, thus raising the possibility that those with impairment have lesions in areas critical for the control of mobility.

OBJECTIVE

To utilize automated image analysis methods to localize the specific regions of abnormal white matter that distinguish subjects with lower mobility from subjects with higher mobility.

METHODS

Tissue classification was performed on subjects' dual-echo long repetition time spin-echo MRI using computer algorithms operating on intensity criteria integrated with anatomic information. Statistical analysis of group differences was obtained after spatially normalizing each brain to a standard reference brain.

RESULTS

Four discrete periventricular regions, including bilaterally symmetric frontal and bilateral occipitoparietal regions, were identified as being sensitive (frontal) or specific (occipitoparietal) in discriminating the subjects with lower mobility from subjects with higher mobility. The symmetry of these lesions in individual subjects suggested pathology other than arteriolar infarction.

CONCLUSIONS

These results suggest that damage to discrete frontal and occipitoparietal periventricular white matter locations may be associated with a mobility disorder of aging.

The discovery of sulfonylated dipeptides as potent VLA-4 antagonists

Directed screening of a carboxylic acid-containing combinatorial library led to the discovery of potent inhibitors of the integrin VLA-4. Subsequent optimization by solid-phase synthesis afforded a series of sulfonylated dipeptide inhibitors with structural components that when combined in a single hybrid molecule gave a sub-nanomolar inhibitor as a lead for medicinal chemistry. Preliminary metabolic studies led to the discovery of substituted biphenyl derivatives with low picomolar activities. SAR and pharmacokinetic characterization of this series are presented.

Attrition in an exercise intervention: a comparison of early and later dropouts

OBJECTIVE

To identify reasons for dropout and factors that may predict dropout from an exercise intervention aimed at improving physical function in frail older persons.

DESIGN/SETTING

An 18-month randomized controlled intervention in a community setting. The intervention comprised 2 groups: class-based and self-paced exercise.

PARTICIPANTS

155 community-dwelling older persons, mean age 77.4, with mildly to moderately compromised mobility.

MEASUREMENTS

The primary outcome measure was dropout. Dropouts were grouped as: D0, dropout between baseline and 3-month assessment, and D3, dropout after 3-month assessment.

MEASUREMENTS

Measurements of demographics, health, and physical performance included self-rated health, SF-36, disease burden, adverse events, PPT-8, MacArthur battery, 6-minute walk, and gait velocity.

RESULTS

There were 56 dropouts (36%), 31 in first 3 months. Compared with retained subjects (R), the D0 group had greater disease burden (P = .011), worse self-perceived physical health (P = .014), slower usual gait speed (P = .001), and walked a shorter distance over 6 minutes (P<.001). No differences were found between R and D3. Multinomial logistic regression showed 6-minute walk (P<.001) and usual gait velocity (P<.001) were the strongest independent predictors of dropout. Controlling for all other variables, adverse events after randomization and 6-minute walk distance were the strongest independent predictors of dropout, and self-paced exercise assignment increased the risk of dropout.

CONCLUSIONS

We observed baseline differences between early dropouts and retained subjects in disease burden, physical function, and endurance, suggesting that these factors at baseline may predict dropout. Improved understanding of factors that lead to and predict dropout could allow researchers to identify subjects at risk of dropout before randomization. Assigning targeted retention techniques in accordance with these factors could result in decreased attrition in future studies. Therefore, the results of selective attrition of frailer subjects, such as decreased heterogeneity, restricted generalizability of study findings, and limited understanding of exercise effects in this population, would be avoided.

Quantitative, low cycle, crack initiation fatigue testing of fine wires and CENELEC standard pacing coil

Uniaxial fatigue testing was performed on different diameters of fine wires made from MP35N. The fatigue limits of the wires differed from each other based on the diameter of the wire. Multiaxial (shear) fatigue testing was also performed on a benchmark coil used to evaluate the fatigue life of all modern pacemaker leads (the CENELEC standard coil). A computer algorithm was used to quantify the maximum shear stress and strain on the coil. The bend radius, coil diameter, wire diameter, and pitch of the coil all affect the shear stress and strain and therefore the fatigue properties of conductor coils. Based on the analysis presented, it was determined that the portion of the CENELEC standard dealing with fatigue, when used in its present format, is not a valid fatigue test for pacemaker leads.

Fixed-dose, body weight-independent subcutaneous LMW heparin versus adjusted dose unfractionated intravenous heparin in the initial treatment of proximal venous thrombosis. EASTERN Investigators

BACKGROUND

Body weight-adjusted subcutaneous low-molecular-weight heparin (LMWH) has been proven to be at least as effective and safe as dose-adjusted intravenous unfractionated heparin (UFH) for the treatment of patients with venous thromboembolism. However, body weight-adjusted dosage of low-molecular-weight heparin may be cumbersome and could lead possibly to incorrect dosing. Therefore a fixed LMWH dose, independent of body-weight, might rationalize initial treatment for venous thromboembolism.

METHODS

Patients with proven proximal deep-vein thrombosis were randomly assigned to fixed dose subcutaneous LMWH Certoparin (8,000 anti-factor Xa U b.i.d.; 265 patients) or to adjusted dose i.v. UFH (273 patients) for 12 days. Vitamin K antagonists were started between day 3 and 7 and continued for up to 6 months. The primary outcome measure was a 30 percent or greater improvement in the Marder Score, as revealed by repeated venography on day 12 (end of the initial treatment). The secondary composite outcome measure included death, recurrent venous thromboembolism and major bleeding and was assessed at day 12 and after 6 months by a blinded adjunction committee.

RESULTS

The Marder score improved by 30% or more in 30.3% and 25.0% of patients assigned to LMWH (198 paired venograms) and UFH (192 paired venograms), respectively (2p = 0.26). At the end of the initial treatment, the composite outcome was observed in 4 of the 265 patients (1.5%) randomized to LMWH, as compared with 14 of the 273 patients (5.1%) randomized to UFH (2p = 0.03). At 6 months these figures were 6.8% and 12.8%, respectively (risk reduction 0.53, confidence interval 0.31-0.90, 2p = 0.02).

CONCLUSION

Fixed dose subcutaneous LMWH certoparin is at least as efficacious as UFH in resolving proximal vein thrombosis.

An accurate, convective energy equation based automated meshing technique for analysis of blood vessels and tissues

An automated three-element meshing method for generating finite element based models for the accurate thermal analysis of blood vessels imbedded in tissue has been developed and evaluated. The meshing method places eight noded hexahedral elements inside the vessels where advective flows exist, and four noded tetrahedral elements in the surrounding tissue. The higher order hexahedrals are used where advective flow fields occur, since high accuracy is required and effective upwinding algorithms exist. Tetrahedral elements are placed in the remaining tissue region, since they are computationally more efficient and existing automatic tetrahedral mesh generators can be used. Five noded pyramid elements connect the hexahedrals and tetrahedrals. A convective energy equation (CEE) based finite element algorithm solves for the temperature distributions in the flowing blood, while a finite element formulation of a generalized conduction equation is used in the surrounding tissue. Use of the CEE allows accurate solutions to be obtained without the necessity of assuming ad hoc values for heat transfer coefficients. Comparisons of the predictions of the three-element model to analytical solutions show that the three-element model accurately simulates temperature fields. Energy balance checks show that the three-element model has small, acceptable errors. In summary, this method provides an accurate, automatic finite element gridding procedure for thermal analysis of irregularly shaped tissue regions that contain important blood vessels. At present, the models so generated are relatively large (in order to obtain accurate results) and are, thus, best used for providing accurate reference values for checking other approximate formulations to complicated, conjugated blood heat transfer problems.

On the use of primary reference grade polydimethylsiloxane

There has been an increase in the use of primary reference material as a standard for identifying the cellular response to biomaterials. One such material is NHLBI-DTB polydimethylsiloxane (PDMS). The PDMS was developed for blood contacting studies and is composed of PDMS backed on one side with mylar. The results of implantation studies of two different publications are discussed in light of the different materials and different surface topographies of each of the materials. The appropriateness of in vivo studies using this reference material is questioned.

The role of ultrasound in patients with possible penetrating cardiac wounds: a prospective multicenter study

BACKGROUND

Ultrasound is quickly becoming part of the trauma surgeon's practice, but its role in the patient with a penetrating truncal injury is not well defined. The purpose of this study was to evaluate the accuracy of emergency ultrasound as it was introduced into five Level I trauma centers for the diagnosis of acute hemopericardium.

METHODS

Surgeons or cardiologists (four centers) and technicians (one center) performed pericardial ultrasound examinations on patients with penetrating truncal wounds. By protocol, patients with positive examinations underwent immediate operation. Vital signs, base deficit, time from examination to operation, operative findings, treatment, and outcome were recorded.

RESULTS

Pericardial ultrasound examinations were performed in 261 patients. There were 225 (86.2%) true-negative, 29 (11.1%) true-positive, 0 false-negative, and 7 (2.7%) false-positive examinations, resulting in sensitivity of 100%, specificity of 96.9%, and accuracy of 97.3%. The mean time from ultrasound to operation was 12.1+/-5 minutes.

CONCLUSION

Ultrasound should be the initial modality for the evaluation of patients with penetrating precordial wounds because it is accurate and rapid.

Electron microscopy and capillaroscopically guided nailfold biopsy in connective tissue diseases: detection of ultrastructural changes of the microcirculatory vessels

The aims of the study were to describe and compare the frequency and nature of histologically detectable microvascular lesions in patients with various connective tissue diseases (CTD). An electron microscopic examination of specimens obtained by the technique of capillaroscopically guided nailfold biopsy was performed in 52 patients with CTD [nine systemic lupus erythematosus (SLE), eight mixed CTD, 18 scleroderma, 17 undifferentiated CTD] and 27 controls. The microvascular changes most frequently observed by electron microscopy were multilayering of the basal lamina (approximately 70% of the CTD patients), an increased amount of perivascular connective tissue, perivascular oedema formation, and an increased number of perivascular fibroblasts and mast cells (each in 30-37% of the CTD patients). In contrast, no particular histopathological feature was found in > 25% of the controls, multilayering (22.6%) being the most frequently observed. Comparing the different conditions studied, there were distinct differences in the frequency and nature of the histologically observed microvascular changes. In particular, SLE seems to be based on a separable type of vasculopathy consisting of significantly less frequent microvascular abnormalities. In conclusion, ultrastructural abnormalities of the microvascular system are a frequent finding in CTD. Electron microscopic examination of specimens obtained by capillaroscopically guided nailfold biopsy is able to disclose histopathological differences between defined entities. Therefore, this approach may be a useful tool to gain further insights into potentially separable aetiopathological mechanisms of the various types of CTD.

Early detection of hemoperitoneum by ultrasound examination of the right upper quadrant: a multicenter study

BACKGROUND

The focused assessment for the sonographic examination of the trauma patient (FAST) is a rapid diagnostic test that sequentially surveys for hemopericardium and then the right upper quadrant (RUQ), left upper quadrant (LUQ), and pelvis for hemoperitoneum in patients with potential truncal injuries. The sequence of the abdominal part of the examination, however, has yet to be validated. The objectives of this multicenter study were as follows: (1) to determine where hemoperitoneum is most frequently identified on positive FAST examinations; and (2) to determine if a relationship exists between that areas and the organs injured.

METHODS

Ultrasound registries from four Level I trauma centers identified patients who had true-positive FAST examinations. Demographic data, areas positive on the FAST, and organs injured were recorded; injuries were classified as multiple, single solid organ (liver or spleen), isolated hollow viscus, or retroperitoneal. Relationships between positive locations on the FAST examinations and the associations of organs injured to areas positive were assessed using McNamara's chi2 test; a p value < 0.05 was considered statistically significant.

RESULTS

The RUQ was the most common site where hemoperitoneum was detected, and this was statistically significant compared with either the LUQ or the pelvis. Also, statistically significant correlations (p < 0.001) were observed between positive RUQ areas on the FAST and multiple injuries, single solid organ (liver or spleen) injury, and retroperitoneal injuries.

CONCLUSION

Blood is most often found on the FAST in the RUQ area in patients with multiple intraperitoneal injuries or isolated injury to the liver, spleen, or retroperitoneum, but not when there is injury to a hollow viscus.

Characterization and quantitation of NF-kappaB nuclear translocation induced by interleukin-1 and tumor necrosis factor-alpha. Development and use of a high capacity fluorescence cytometric system

A new quantitative cytometric technique, termed the ArrayScanTM, is described and used to measure NF-kappaB nuclear translocation induced by interleukin (IL)-1 and tumor necrosis factor-alpha (TNFalpha). The amount of p65 staining is measured in both the nuclei defined by Hoechst 33342 labeling and in the surrounding cytoplasmic area within a preselected number of cells/well in 96-well plates. Using this technique in synchronously activated human chondrocytes or HeLa cells, NF-kappaB was found to move to the nucleus with a half-time of 7-8 min for HeLa and 12-13 min for chondrocytes, a rate in each case about 4-5 min slower than that of Ikappa Balpha degradation. IL-1 receptor antagonist and anti-TypeI IL-1 receptor antiserum on the one hand and anti-TNFalpha and monoclonal anti-TNF receptor 1 antibodies on the other hand could be shown to respectively inhibit IL-1 and TNFalpha stimulation in both cell types. In contrast, a polyclonal anti-TNF receptor 1 antiserum exhibited both a 50% agonism and a 50% antagonism to a TNFalpha stimulation in a dose-dependent fashion, indicating that subtle functional responses to complex agonist and antagonist stimuli could be measured. The effects of different proteasome inhibitors to prevent Ikappa Balpha degradation and subsequent NF-kappaB translocation could also be discriminated; Leu-Leu-Leu aldehyde was only a partial inhibitor with an IC50 of 2 microM, while clastolactacystin beta-lactone was a complete inhibitor with an IC50 of 10 microM. The nonselective kinase inhibitor K252a completely inhibited both IL-1 and TNFalpha stimulation in both cell types with an IC50 of 0.4 microM. This concentration, determined after a 20-min stimulation, was shown to be comparable with that obtained for inhibition of IL-6 production induced by a 100-fold lower IL-1 and TNFalpha concentration measured after 17 h of stimulation. These results suggest that the ArrayScanTM technology provides a rapid, sensitive, quantitative technique for measuring early events in the signal transduction of NF-kappaB.

Surgeon-performed ultrasound for the assessment of truncal injuries: lessons learned from 1540 patients

OBJECTIVE

To determine the accuracy of the Focused Assessment for the Sonographic examination of the Trauma patient (FAST) when performed by trauma team members during a 3-year period, and to determine the clinical conditions in which the FAST is most accurate in the assessment of injured patients.

SUMMARY BACKGROUND DATA

The FAST is a rapid test that sequentially surveys the pericardial region for hemopericardium and then the right and left upper quadrants and pelvis for hemoperitoneum in patients with potential truncal injuries. The clinical conditions in which the FAST is most accurate in the assessment of injured patients have yet to be determined.

METHODS

FAST examinations were performed on patients with precordial or transthoracic wounds or blunt abdominal trauma. Patients with a positive ultrasound (US) examination for hemopericardium underwent immediate surgery, whereas those with a positive US for hemoperitoneum underwent a computed tomography scan (if they were hemodynamically stable) or immediate celiotomy (if they were hemodynamically unstable- blood pressure < or = 90 mmHg).

RESULTS

FAST examinations were performed in 1540 patients (1227 with blunt injuries, 313 with penetrating injuries). There were 1440 true-negative results, 80 true-positive results, 16 false-negative results, and 4 false-positive results; the sensitivity was 83.3%, the specificity 99.7%. US was most sensitive and specific for the evaluation of patients with precordial or transthoracic wounds (sensitivity 100%, specificity 99.3%) and hypotensive patients with blunt abdominal trauma (sensitivity 100%, specificity 100%).

CONCLUSIONS

US should be the initial diagnostic modality for the evaluation of patients with precordial wounds and blunt truncal injuries because it is rapid and accurate. Because of the high sensitivity and specificity of US in the evaluation of patients with precordial wounds and hypotensive patients with blunt torso trauma, immediate surgical intervention is justified when those patients have a positive US examination.

Infrared thermography in the diagnosis of Raynaud's phenomenon in vibration-induced white finger

BACKGROUND

Frequent use of vibrating tools over several years may lead to a neurovascular disturbance of finger circulation with the development of typical Raynaud's phenomenon, attacks being triggered by vibration and/or cold exposure. The condition is recognized as an occupational disease and known as vibration-induced white finger (VWF). Aim of the present study was to evaluate the usefulness of infrared thermography (IRT) with a cold provocation test in the diagnosis of Raynaud's phenomenon in VWF.

PATIENTS AND METHODS

24 patients with the diagnosis of VWF, previously established by other methods, were compared with 12 matched control subjects. We carried out IRT-measurements simultaneously on both hands before, directly after and 5, 10, 15, 20, and 30 mins following a 3 min exposure of both hands to a waterbath of 12 degrees C. The results of temperature measurements of all fingers were analyzed and the time to complete rewarming of all fingers was recorded.

RESULTS

The basal thermograms did not differ between both groups, whereas the mean finger temperatures after cold exposure were significantly lower in VWF-patients compared to controls, with a considerable individual overlap between both groups. Therefore, determination of absolute finger temperature reveals not to be a useful diagnostic tool in individual cases, but might be helpful for pharmacological studies (group-analysis). In contrast to absolute finger temperatures, the parameter of rewarming time after cold exposure revealed to be diagnostic on an individual basis: a complete rewarming after 15 min indicates a normal vascular reactivity and an incomplete rewarming 30 min following the cold provocation points to an impaired vascular reactivity due to VWF.

CONCLUSIONS

IRT revealed to be a useful tool in the diagnosis of Raynaud's phenomenon in VWF, and provides a sufficient documentation suitable for further follow-up examination.

Validation of surgeon-performed emergency abdominal ultrasonography in pediatric trauma patients

BACKGROUND/PURPOSE

The focused assessment for the sonographic evaluation of trauma patients (FAST) in adults is effective in detecting intraperitoneal and intrapericardial fluid and can be performed quickly by surgeons in the emergency department (ED). The authors sought to validate the accuracy of FAST performed by surgeons during ED resuscitation of pediatric trauma patients.

METHODS

Patients were assigned to one of three groups based on standard clinical criteria: immediate surgery, abdominal computed tomography (CT), or observation alone. FAST was then performed in the ED by a surgery resident (postgraduate year 3 or higher) or an attending trauma surgeon. Four views were used to assess the possible presence of fluid in the pericardial, subphrenic, subhepatic, and pelvic spaces. Time needed to conduct FAST was noted. Presence of peritoneal or pericardial fluid by FAST was compared with that determined by CT or surgery. Sensitivity, specificity, and predictive values were calculated. For those who did not undergo CT or surgery, FAST findings were compared with the clinical course.

RESULTS

Technically adequate studies could be performed on 192 of 196 eligible children. Their ages ranged from 3 months to 14 years (mean, 6.9 years); 119 were boys (62%), and 188 (98%) had sustained a blunt injury. FAST was performed in a mean time of 3.9 minutes (range, 1-17 minutes). All FAST examinations were reviewed by our senior surgeon-sonographer (GSR). Interrater agreement between the performing and reviewing surgeon-sonographer was 100%. Sixty (31%) patients underwent either abdominal CT (n = 56; mean Injury Severity Score (ISS), 9.6) or immediate operation (n = 4; mean ISS, 18.8). Of the 10 patients with verified presence of intraperitoneal fluid, eight had positive and two had false-negative FAST examination results. Of the 50 patients with verified absence of intraperitoneal fluid, none had a positive FAST (ie, no false-positives); sensitivity was 80%; specificity, 100%; predictive value positive, 100%; predictive value negative, 96%. None of the 132 patients followed up clinically without CT or surgery (mean ISS, 4.5) had fluid documented by FAST, and all did well.

CONCLUSIONS

The focused assessment for the sonographic evaluation of pediatric blunt trauma patients performed by surgical residents and attendings in the ED rapidly and accurately predicted the presence or absence of intraperitoneal fluid. The FAST is a potentially valuable tool to rapidly prioritize the need for laparotomy in the child with multiple injuries and extraabdominal sources of bleeding.

Bipolar pacemaker leads: new materials, new technology

This commentary is in response to a review published earlier in this journal. It is intended to provide additional information and supplement the original paper. A short review of the failure mechanisms of polyurethane pacing lead materials is provided. Two specific degradation mechanisms, environmental stress cracking and metal ion oxidation, are discussed. Environmental stress cracking has been extensively studied and is a well understood failure mechanism. Methods for reducing the problem have been developed and tested in vivo. As a result, stress cracking failures can be virtually eliminated. Metal ion oxidation failures now dominate pacing lead recalls. Two new materials, polycarbonate urethanes and ethylenetetrafluoroethylene, have been introduced as insulators for pacing leads. These materials do not fail by stress cracking and preliminary test results are very positive.

[Standardization of nailfold capillary microscopy in routine diagnosis]

BACKGROUND

Nailfold capillary microscopy is scientifically established and recognized as a diagnostic tool in clinical routine. It is, however, practiced in only a few centres.

METHODS

But since a more widespread use of the method is to be expected for the near future, a consensus-meeting was held, where all German-speaking clinicians and scientists, involved in capillary microscopy, were invited. Here, the technical procedure and the most important morphological parameters were evaluated and defined according to practical clinical aspects.

RESULTS AND CONCLUSION

The main task of the consensus-meeting was to develop a standard evaluation sheet, accompanied by an explanation sheet. This standard evaluation sheet focuses on semiquantitative registration of morphological parameters like density, dilation, avascular fields, perivascular edema, microbleeding, torsion, atypical capillaries and giant capillaries. This standard evaluation sheet is to be validated by determining the inter-observer-variance. Later-on an illustrated practical guideline will be published.

Expression and immunoaffinity purification of human inducible nitric-oxide synthase. Inhibition studies with 2-amino-5,6-dihydro-4H-1,3-thiazine

Recombinant human inducible nitric-oxide synthase (rH-iNOS) was expressed in the baculovirus system and purified by a novel immunoaffinity column. rH-iNOS and its native counterpart from cytokine-stimulated primary hepatocytes exhibited similar molecular mass of 130 kDa on SDS-polyacrylamide gel electrophoresis, recognition by antipeptide antibodies, specific activities, and IC50 values for inhibitors. The active dimeric form exhibited a specific activity range of 114-260 nmol/min/mg at 37 degrees C and contained 1.15 +/- 0.04 mol of calmodulin/monomer. The enzyme exhibited a Soret lambdamax at 396 nm with a shoulder at 460 nm and contained 0. 28-0.64 mol of heme/monomer. Dithionite reduction under CO yielded an absorbance maximum at 446 nm, indicating a P450-type heme. Imidazole induced a type II difference spectrum, reversible by L-Arg. 2-Amino-5,6-dihydro-4H-1,3-thiazine (ADT) was competitive versus L-Arg (Ki = 22.6 +/- 1.9 nM), reversed the type II difference spectrum induced by imidazole (Kd = 17.7 nM), and altered the CO-ferrous absorbance of rH-iNOS. L-Arg did not perturb the CO-ferrous adduct directly, but it partially reversed the ADT-induced absorbance shift, indicating that both bind similarly to the protein but interact differently with the heme.

Acute effects of therapeutic ultrasound delivered at varying parameters on the blood flow velocity in a muscular distribution artery

Therapeutic modalities that alter hemodynamic parameters may have a dramatic impact on the viability of living tissues. The purpose of the current study was to investigate the response of blood flow velocity to various treatment parameters of therapeutic ultrasound. Twenty healthy volunteers attended six randomly selected, 15-minute treatment sessions of the following parameters: Tx-1 = 1.0 MHz at 1.5 W/cm2, Tx-2 = 1.0 MHz at 1.0 W/cm2; Tx-3 = 3.0 MHz at 1.2 W/cm2; Tx-4 = 3.0 MHz at 1.0 W/cm2, Tx-5 = sham; and Tx-6 = control. Ultrasound was applied to a circular area over the triceps surae muscle mass. Blood flow velocity in the popliteal artery was assessed after 5, 10, and 15 minutes of ultrasound and at two posttreatment intervals via a dual frequency, bidirectional ultrasound Doppler. A two-factor analysis of variance (p < or = 0.05) with repeated measures for treatment and time was performed on the data. Groups Tx-1 and Tx-2 showed significant increases in blood flow velocity when compared with the control and all other groups. The sham group showed significant increases in blood flow velocity when compared with the control group. Group Tx-3 and Tx-4 showed no significant change when compared with the sham condition. The results of the current study indicate that 1.0 MHz ultrasound delivered at 1.0 and 1.5 W/cm2 to the triceps surae musculature as described in the present study can increase the blood flow velocity in the popliteal artery.

Gas-phase reactions of glycine, alanine, valine and their N-methyl derivatives with the nitrosonium ion, NO+

The gas-phase reactions of the nitrosonium ion, NO+ with the amino acids glycine, alanine and valine and their N-methyl derivatives were investigated under chemical ionization mass spectrometric (CIMS) conditions. Two products were observed in all cases: the formation of the iminium ion and the formation of an [M-H]+ ion. The latter product is consistent with a reaction channel involving hydride abstraction by NO+, and was confirmed by (i) examining the Ar+CI mass spectra of the same amino acids under similar source conditions and (ii) examining the unimolecular fragmentation reactions of the [M + H]+ ions of the N-nitroso-N-methyl derivatives of each of the amino acids in a tandem mass spectrometer. Further insights into the reaction of glycine with NO+ were obtained by performing ab initio calculations (at the MP2/6-31G* parallel HF/6-31G* level). These results indicate that four reactions are thermodynamically viable for glycine: (i) hydride abstraction; (ii) iminium ion formation (with concomitant loss of HONO and CO); (iii) diazonium ion formation; and (iv) diazonium ion formation followed by loss of N2. Possible reasons why reactions (iii) and (iv) are not observed are discussed, and comparisons with solution reactivity and the gas-phase reactivity of NO+ are also made.

Ultrasound training during ATLS: an early start for surgical interns

OBJECTIVES

Determine if: (1) surgical interns could learn essential ultrasound principles of the focused assessment for the sonographic examination of the trauma patient (FAST) during Advanced Trauma Life Support (ATLS), and (2) swine are adequate models for learning the FAST.

DESIGN

Lecture, videotape, pre/posttests, and practical examination.

METHODOLOGY

Day 1: Survey, pretest, lecture, and videotape. Day 2: Three swine, used in ATLS, had diagnostic peritoneal lavage catheters reinserted to infuse fluid and produce "positive" ultrasound examinations. Two fresh swine were "negatives"; however, all five swine were draped similarly to disguise interventions. Interns were tested individually by surgeon-sonographers to determine whether the ultrasound image was "positive" or "negative." Posttests were completed while surgeons performed postmortem examinations on two swine.

STATISTICS

Paired Student's t test and Wilcoxon Rank Sum test.

RESULTS

Survey (5 min): 48% had exposure to ultrasound. Relationship of test scores showed no significant difference (p = 0.46 to 0.91) between interns with and without ultrasound experience. Tests (30 min): Mean pre- and posttests scores = 65.6 and 90.8, respectively (p < 0.001). Practical examination (140 min): Mean score = 89.6. Postmortem examinations: Left hepatic lobe partially obscured the spleen.

CONCLUSIONS

(1) Surgical interns can learn essential ultrasound principles of the FAST during ATLS (2) Swine are feasible models for learning the FAST.

Active-site structure analysis of recombinant human inducible nitric oxide synthase using imidazole

Nitric oxide synthase catalyzes the pyridine nucleotide-dependent oxidation of L-arginine to nitric oxide and L-citrulline. It is a specialized cytochrome P450 monooxygenase that is sensitive to inhibition by imidazole. Steady-state kinetic studies on recombinant human inducible nitric oxide synthase (rH-iNOS) demonstrate that imidazole and 1-phenylimidazole are competitive and reversible inhibitors versus L-arginine. Structure-activity relationship and pH dependence studies on the inhibition suggest that the neutral form of imidazole may be the preferred species and that the only modifications allowed without the loss of inhibition are at the N-1 position of imidazole. Optical spectrophotometric studies of rH-iNOS with imidazole and 1-phenylimidazole yielded type II difference spectra exhibiting Kd values of 63 +/- 2 and 28 +/- 3 microM, respectively. These values were in good agreement with the steady-state Ki of 95 +/- 10 and 38 +/- 4 microM, respectively, and confirms the site of binding is at the sixth axial ligand of the heme. Imidazole (2.2 mM) also perturbed the Kd of L-arginine from 3.03 +/- 0.45 to 209 +/- 10 microM. The observed increase in the Kd for L-arginine is consistent with imidazole being a competitive inhibitor versus L-arginine. The IC50 values of imidazole and 1-phenylimidazole were lower in the absence of exogenous BH4, and both inhibitors also competitively inhibited the BH4-dependent activation of the enzyme. These data taken together suggest that the L-arginine, dioxygen, and the BH4 binding sites are in close proximity in rH-iNOS. Furthermore, these studies demonstrate the usefulness of imidazole compounds as active site probes for recombinant human iNOS.