Compositional analysis of oxide-embedded III-V nanostructures.

Nanowire growth enables creation of embedded heterostructures, where one material is completely surrounded by another. Through materials-selective post-growth oxidation it is also possible to combine amorphous oxides and crystalline, e.g. III-V materials. Such oxide-embedded structures pose a challenge for compositional characterization through transmission electron microscopy since the materials will overlap in projection. Furthermore, materials electrically isolated by an embedding oxide are more sensitive to electron beam-induced alterations. Methods that can directly isolate the embedded material, preferably at reduced electron doses, will be required in this situation. Here, we analyse the performance of two such techniques-local lattice parameter measurements from high resolution micrographs and bulk plasmon energy measurements from electron energy loss spectra-by applying them to analyse InP-AlInP segments embedded in amorphous aluminium oxide. We demonstrate the complementarity of the two methods, which show an overall excellent agreement. However, in regions with residual strain, which we analyse through molecular dynamics simulations, the two techniques diverge from the true value in opposite directions.

Disentangling Spectral Phases of Interfering Autoionizing States from Attosecond Interferometric Measurements.

We have determined spectral phases of Ne autoionizing states from extreme ultraviolet and midinfrared attosecond interferometric measurements and ab initio full-electron time-dependent theoretical calculations in an energy interval where several of these states are coherently populated. The retrieved phases exhibit a complex behavior as a function of photon energy, which is the consequence of the interference between paths involving various resonances. In spite of this complexity, we show that phases for individual resonances can still be obtained from experiment by using an extension of the Fano model of atomic resonances. As simultaneous excitation of several resonances is a common scenario in many-electron systems, the present work paves the way to reconstruct electron wave packets coherently generated by attosecond pulses in systems larger than helium.

Children's experiences about a structured assessment of health-related quality of life during a patient encounter.

BACKGROUND: It has been stated that care for children with chronic health conditions tends to focus on condition-specific issues rather than how these children experience their health and everyday life functioning. AIM: The aim of this study was to explore children's experiences about a structured assessment of health-related quality of life applied during a patient encounter. METHODS: Prior to the start of the study, a clinical intervention based on the questionnaire DISABKIDS Chronic Generic Measure (DCGM-37) was performed. A qualitative explorative design was chosen, and 25 children between 10-17 years of age were interviewed after the consultation at four different paediatric outpatient clinics. Data were analysed according to qualitative content analysis. RESULTS: The results were twofold: children experienced that the assessment was providing them with insights about their health, which motivated them to make lifestyle changes. When outcomes were discussed and requested, the children felt encouraged. CONCLUSIONS: The use of an assessment of health-related quality of life may promote insights about health and encourage children with chronic health conditions to discuss their outcomes with healthcare professionals.

Allergens. Heterogeneity of molecular sensitization profiles in grass pollen allergy--implications for immunotherapy?

BACKGROUND: Data on molecular allergy diagnostics in adults with grass pollen allergy with regard to conjunctival and nasal provocation test outcome and specific immunotherapy are lacking to date. OBJECTIVE: To assess whether molecular allergy diagnostics for grass pollen allergens could help with predicting provocation test outcomes and serve as a basis for future component-resolved specific immunotherapy. METHODS: Sera of 101 adults with grass pollen allergy was analysed for IgE against timothy grass pollen (Phleum pratense), rPhl p 1, rPhl p 2, nPhl p 4, rPhl p 5b, rPhl p 6, rPhl p 7, rPhl p 11 and rPhl p12 and correlated with the individuals' outcome in the nasal and conjunctival provocation tests and investigated in regard to a potential component-resolved specific immunotherapy. RESULTS: An increasing number of sensitizations to timothy grass allergens was correlated to a positive reaction in the conjunctival (4.9 vs. 3.6, P = 0.003) and nasal provocation tests (4.5 vs. 2.2, P = 0.0175). In molecular sensitization profiles, a substantial heterogeneity was detected, with none of the patients exactly matching the allergen composition of a previously published component-resolved specific immunotherapy containing Phl p 1, Phl p 2, Phl p 5a/b and Phl p 6. The results indicate that in 95% of the patients, a proportion of 50% of timothy-IgE would be targeted with such a specific immunotherapy, while in 50% and 10% of patients, 80% and 90% of timothy-IgE would be targeted, respectively. CONCLUSION AND CLINICAL RELEVANCE: Molecular allergy diagnostics is a prerequisite for future component-resolved specific immunotherapy due to the high heterogeneity of sensitization profiles. However, of current clinical relevance is the observed correlation between the number of sensitizations and provocation test outcome.

Can immunoglobulin E-measurement replace challenge tests in allergic rhinoconjunctivits to grass pollen?

BACKGROUND: There is minimal data available concerning the dose-response relationship between allergen exposure and clinical reactivity for outdoor aeroallergens, such as timothy grass pollen. Timothy pollen-specific IgE (sIgE) determinations might assist in predicting the clinical reactivity in patients with allergic rhinoconjunctivitis (ARC). METHODS: Allergen-sIgE antibody levels of timothy grass pollen were correlated with individual threshold doses eliciting allergic reactions in skin prick test (SPT), conjunctival (CPT) and nasal (NPT) provocation tests in patients suffering from pollen-induced rhinoconjunctivitis and healthy controls. RESULTS: One hundred and four patients with ARC (median age: 27 years; range: 18-64; females: 58%) and 36 controls (25 years (22-77); females: 70%) were included in the study. Ninety-six percent of the patients showed a positive reaction in the nasal and 57% showed a positive reaction in the conjunctival provocation. With regarding to titrated SPT, 98% of the patients showed a positive skin test reaction; correlating with the level of sIgE for timothy (P < 0.001). For both provocation protocols, there was no correlation between the provocation concentration at the reaction and the level of sIgE for timothy. The ratio of sIgE/total IgE correlated with the dilution level of SPT (P < 0.002) and CPT (P < 0.01), respectively. CONCLUSION AND CLINICAL RELEVANCE: A dose-response relationship between the levels of sIgE and clinical outcome of timothy allergen exposure could not be established. Although IgE-determination remains an important key element in allergy diagnosis, provocation tests are procedures of choice if the clinical relevance of an allergen has to be confirmed.

Evaluation of the human prediction of clearance from hepatocyte and microsome intrinsic clearance for 52 drug compounds.

We compare three different approaches to scale clearance (CL) from human hepatocyte and microsome CL(int) (intrinsic CL) for 52 drug compounds. By using the well-stirred model with protein binding included only 11% and 30% of the compounds were predicted within 2-fold and the average absolute fold errors (AAFE) for the predictions were 5.9 and 4.1 for hepatocytes and microsomes, respectively. When predictions were performed without protein binding, 59% of the compounds were predicted within 2-fold using either hepatocytes or microsomes and the AAFE was 2.2 and 2.3, respectively. For hepatocytes and microsomes there were significant correlations (P = 8.7 x 10(-13), R(2) = 0.72; P = 2.8 x 10(-9), R(2) = 0.61) between predicted CL(int in vivo) (obtained from in vitro CL(int)) and measured CL(int in vivo) (obtained using the well-stirred model). When CL was calculated from the regression, 76% and 70% of the compounds were predicted within 2-fold and the AAFE was 1.6 and 1.8 for hepatocytes and microsomes, respectively. We demonstrate that microsomes and hepatocytes are in many cases comparable when scaling of CL is performed from regression. By using the hepatocyte regression, CL for 82% of the compounds in an independent test set (n = 11) were predicted within 2-fold (AAFE 1.4). We suggest that a regression line that adjusts for systematic under-predictions should be the first-hand choice for scaling of CL.

Anisotropic photoemission time delays close to a Fano resonance.

Electron correlation and multielectron effects are fundamental interactions that govern many physical and chemical processes in atomic, molecular and solid state systems. The process of autoionization, induced by resonant excitation of electrons into discrete states present in the spectral continuum of atomic and molecular targets, is mediated by electron correlation. Here we investigate the attosecond photoemission dynamics in argon in the 20-40 eV spectral range, in the vicinity of the 3s-1np autoionizing resonances. We present measurements of the differential photoionization cross section and extract energy and angle-dependent atomic time delays with an attosecond interferometric method. With the support of a theoretical model, we are able to attribute a large part of the measured time delay anisotropy to the presence of autoionizing resonances, which not only distort the phase of the emitted photoelectron wave packet but also introduce an angular dependence.

The FHIT and PTPRG genes are deleted in benign proliferative breast disease associated with familial breast cancer and cytogenetic rearrangements of chromosome band 3p14.

We have used nested reverse transcription-PCR (RT-PCR) and PCR on genomic DNA to search for aberrations in the FHIT and PTPRG genes, both located in chromosomal band 3p14.2, in specimens from cytogenetically analyzed benign breast lesions (three samples with atypical hyperplasia and one with fibroadenosis) from two women belonging to breast cancer families. The transcription analysis showed that the FHIT gene was either not expressed or that its expression was dramatically reduced to a level not detectable by nested RT-PCR in the samples with atypical hyperplasia. Genomic analysis of exons 3 and 5 of FHIT and exon 12 of PTPRG provided evidence that these DNA segments were homozygously deleted in the majority of the cells. These data are in line with the histopathological features and cytogenetic findings in the three samples; none contained normal parenchyma, and all had chromosomal aberrations involving band 3p14. RT-PCR analysis of the fibroadenosis specimen, which had a normal karyotype, detected the expected 856-bp fragment as well as an additional alternative transcript variant of FHIT with 1014 bp. The additional 158-bp sequence, which may add 38 amino acids to the NH2-terminal part of the previously described FHIT protein, was inserted between exons 4 and 5 and seems to be a new exon located in intron 4 of FHIT.

Increased fragility in patients with fracture of the proximal humerus: a case control study.

The aim of this study was to evaluate whether a fracture of the proximal humerus is associated with an increased prevalence of preceding fractures or a risk of subsequent fractures. All patients who were treated at the Malmö General Hospital in 1987 for a fresh fracture of the proximal humerus were identified, representing practically all fractures of the proximal humerus in Malmö city (250,000) that year. Two hundred fifty-three adult patients, 54 men with an average age of 66 (24-90) and 199 women with a mean age of 74 (22-98) years, were included in the study together with 475 age- and gender-matched control persons. In 1999, fracture prevalence of patients and controls were rated by a survey at the Dept. of Radiology. There was a significantly increased prevalence of previous fractures before 1987 in the humerus fracture group with an odds ratio (OR) of 3.5 [95% confidence interval (95% CI), 2.2-5.5] for a spinal fracture, OR 1.8 (95% CI, 1.3-2.6) for a previous fracture to the upper extremity, and OR 1.8 (95% CI, 1.2-2.6) for a preceding fracture of the lower limb. The proximal humerus fracture also predicted a significantly increased risk of a subsequent fracture. The hazard ratio (HR) was 2.5 (95% CI, 1.7-3.7) for a forthcoming spinal fracture, HR 2.8 (95% CI, 2.0-3.7) for a future fracture of the upper extremity, and HR 2.0 (95% CI, 1.2-3.5) for a lower limb fracture. In a subgroup of male patients, an almost five times increased risk of sustaining subsequent extremity fractures was observed. In summary, a fracture of the proximal humerus is associated both with increased prevalence of previous fractures of the spine and extremities and also predicting an increased risk of future fractures.

The development of an assay for human neutrophil lipocalin (HNL)--to be used as a specific marker of neutrophil activity in vivo and vitro.

Human neutrophil lipocalin (HNL) is a newly discovered protein from human neutrophil secretory granules. A double-antibody radioimmunoassay (RIA) was developed for the measurement of HNL in various body fluids and its high specificity was confirmed by the absence of cross-reaction with other granulocyte granule proteins. The RIA measures HNL within the range of 4-256 micrograms/l. The intra- and interassay coefficients of variation were less than 6% and 10%, respectively. When HNL was added to serum samples full recovery was obtained. Sera and plasma from 100 apparently healthy individuals revealed a mean level of 78.40 micrograms/l (range 37.95-190.87 micrograms/l) in serum and a mean level of 50.65 micrograms/l (range 30.51-105.8 micrograms/l) in EDTA-plasma. The distribution of HNL after gel filtration indicated that HNL exists mainly in two major forms, dimer and monomer. This, in addition to the excellent recovery, suggests that these major forms of HNL do not bind to compounds in serum or plasma that would interfere with the assay. The high specificity, sensitivity, reproducibility and accuracy of the present assay should facilitate the measurement of HNL in blood and other body fluids.

A new method to visualize the Helicobacter pylori-associated Lewis(b)-binding adhesin utilizing SDS-digested freeze-fracture replica labeling.

Freeze-fracture replica labeling has become a versatile tool to visualize both membrane components and other cell structures using SDS-replica cleaning before specific immunogold labeling of proteins or lipids. We report here for the first time the adoption and optimization of the method to studies of bacterial envelopes, as applied to structural analysis of the distribution of the unique BabA-adhesin of the gastric pathogen Helicobacter pylori. BabA is important for bacterial adherence to the human epithelial cell lining of the stomach. The adhesin was found to be distributed all over the bacterial cell surfaces. Our results suggest that the SDS-replica labeling allows assessment of protein localization to distinct cell compartments and analysis of co-localization with neighboring membrane structures.

Clonal chromosome-aberrations in fibrocystic breast disease-associated with increased risk of cancer.

Short-term cultures of 29 samples of fibrocystic breast disease were cytogenetically analyzed. Clonal chromosome aberrations were found in six specimens, whereas the remaining 23 had a normal karyotype. Three of the abnormal samples displayed karyotypic anomalies previously associated with breast cancer, i.e., gain of Iq, trisomy 18 and cytogenetic multiclonality. Furthermore, all cytogenetically aberrant specimens had either proliferative disease without atypia or atypical hyperplasia, features of fibrocystic disease considered risk factors for subsequent breast cancer development. The cytogenetic similarities between breast carcinomas and proliferative fibrocystic breast disease add further support for classifying certain types of fibrocystic disease as a premalignant condition. Whether cytogenetically abnormal fibrocystic lesions are the ones that subsequently progress to cancer remains to be elucidated.

Cytogenetic findings in phyllodes tumors of the breast: karyotypic complexity differentiates between malignant and benign tumors.

Clonal karyotypic abnormalities were detected in short-term cell cultures from six phyllodes tumors of the breast. Whereas all five benign tumors had simple chromosomal changes, the highly malignant one had a near-triploid stemline, indicating that karyotypic complexity is a marker of malignancy in phyllodes tumors. Interstitial deletions of the short arm of chromosome 3, del(3)(p12p14) and del(3)(p21p23),were the only aberrations in two benign tumors. Cytogenetic polyclonality was detected in three benign tumors: two had cytogenetically unrelated clones, whereas the third had three different, karyotypically related cell populations as evidence of clonal evolution. The finding of clonal chromosome abnormalities in both the epithelial and connective tissue components of the phyllodes tumors indicates that they are genuinely biphasic, that is, that both components are part of the neoplastic parenchyma.

Karyotypic changes in phyllodes tumors of the breast.

Cytogenetic analysis of short-term cultures of five phyllodes tumors of the breast-classified as benign (one tumor), borderline malignant (two tumors removed from the same breast in 1991 and 1993), and malignant (two tumors)--revealed clonal changes with simple structural abnormalities in the benign tumor, the borderline malignant tumors, and one malignant tumor in which benign areas and areas of borderline malignancy were also present. In contrast, the malignant tumor without admixed borderline malignant or benign areas had a complex karyotype. The karyotype of the benign phyllodes tumor was 46,XX,del(12)(p11p12)/46,XX,t(8;18)(p11;p11)/46,XX. The first borderline malignant phyllodes tumor had t(3;20)(p21;q13) as the sole abnormality. When the tumor recurred, this was no longer the only clone detected and the tumor karyotype was now 46,XX,t(3;20)(p21;q13)/46,XX,t(9;10)(p22;q22)/46,XX,t(1;8) (p34;q24)/46,XX,del(11)(q22-23)/46,XX. The malignant/borderline malignant/benign tumor had t(1;6)(p34;p22) as the sole clonal abnormality. Finally, the karyotype of the malignant phyllodes tumor which contained no benign or borderline malignant areas was 42,XX,der(1)t(1;4)(q21;q21),der(3)t(3;17)(q29;q21), -4,i(8)(q10), -10, -13,i(13)(q10),der(14)t(1;14)(q21;p11),der(14)t(4;14) (p12;p11), -17/80-90,idemx2, +del(1)(q12), +i(1)(p10), +dic(5;5)(p14;p14), +i(6)(p10), +del(7)(p11), +dup(7)(q11q36), +i(15)(q10),inc/46,XX. The findings indicate some cytogenetic similarities between benign/borderline malignant phyllodes tumors and fibroadenomas of the breast, presumably reflecting similar pathogenetic mechanisms in the two types of mixed-lineage tumors.

Structural and serological characterization of Hafnia alvei lipopolysaccharide core region.

The structures and serological activities of core oligosaccharide of Hafnia alvei strains have been investigated. Methylation analysis, NMR spectroscopy and various specific degradation procedures were the principal methods used. It is concluded that, core hexasaccharides are identical in the lipopolysaccharides tested and are built of two glucose, three heptose and one 2-keto-3-deoxyoctulosonic acid residues. The antiserum raised against the ATCC13337 oligosaccharide core-tetanus toxoid conjugate cross-reacted strongly with all lipopolysaccharides used as antigens in ELISA test, suggesting that this core region is the common structure in the Hafnia genus.

Preparation and characterization of monoclonal antibodies against bovine myeloperoxidase.

We established eight cloned B-cell hybridomas producing monoclonal antibodies (Mo abs) against bovine myeloperoxidase (MPO). These anti-MPO (AM) Mo abs, designated AM1-AM8, all reacted similarly to three chromatographic forms of MPO, isolated from a single donor, in an enzyme linked immunosorbent assay. According to immunoblot analysis and ELISA the AM Mo abs are specific to bovine MPO and show no cross reactivity with other neutrophil granule proteins such as lactoferrin, lactoperoxidase and serum albumin. In immunoblot analyses IgG1 class AM1, AM2, AM3 and AM4 Mo abs immunostained the heavy subunit of the MPO (57 kDa). Additionally, the AM Mo abs seem to bind either the reactive site or epitopes on bovine MPO that affect the peroxidase activity of this enzyme. AM Mo abs reacted specifically with neutrophils but did not react with lymphocytes or epithelial cells. The present study shows that these AM Mo abs could be used for developing immunoassays to measure bovine MPO from biological fluids and for localizing neutrophils at sites of infections. They could also be useful in studies assessing the involvement of MPO in inflammatory processes in bovine species.

Isolation and purification of bovine myeloperoxidase from neutrophil granules.

Bovine myeloperoxidase (MPO) was isolated and purified from neutrophil granules using protein extraction at pH 4 and gel filtration combined with fast protein liquid chromatography. The extracted protein was identified as MPO based on its absorption spectrum, amino acid composition, peroxidase activity and polypeptide structure. Bovine neutrophils contained three different forms of MPO (I, II and III). When subjected to sodium dodecyl sulphate polyacrylamide gel electrophoresis each of the three purified forms showed two distinct bands corresponding to heavy and light polypeptide chains of approximately 57,000 and 15,000 molecular radius. Amino acid analysis of the three forms showed that there was an overall similarity between them. Slight differences were found between MPO Form III and the other two forms. The three forms of bovine MPO were shown to differ in their specific enzyme activities in a luminol-dependent chemiluminescence assay. MPO Form III showed the highest enzyme activity. The amount recovered during purification of the respective MPO forms varied, with the recovery being highest for MPO I. Our findings suggest that there are intrinsic differences between the three forms of bovine MPO. In terms of their amino acid composition and molecular weight, the bovine MPO closely resembled human and canine MPO.

Drug consumption during the first 18 months of life of infants from smoking and non-smoking families.

In a geographically well defined population in southern Sweden, a study was made of the overall consumption of drugs by infants during their first 18 months of life. The study population comprised 240 infants, of whom 90 were from families where tobacco was smoked by one or both parents and 150 were from non-smoking families. The investigation was carried out retrospectively by interviewing the mothers at the routine 18-month check up at the child health clinic, combined with study of the medical records at the district health centre, and at the paediatric and ear, nose and throat departments of the nearby hospital. In addition, the reliability of the interview method compared with review of medical records was investigated. Particular attention was paid to the consumption of antibiotics and the relationship between 'passive smoking' and consumption of antibiotics necessitated by respiratory tract infections. There was widespread use of both prescribed and non-prescription remedies. At the age of 18 months, about two thirds of all infants in the area had been prescribed an antibiotic (or other antibacterial agent) on at least one occasion. Infants from smoking families had been prescribed significantly more antibiotics than had infants from non-smoking families. The same pattern was also apparent for nose drops and dimethicone/dicyclomine hydrochloride. The incidence of respiratory tract infections requiring antibiotic treatment was higher in infants from smoking families than from non-smoking families in all the three-month age groups up to 15 months. The responses to the retrospective interview accorded closely with the details recorded in the medical records.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural studies of the O-specific chain of Hafnia alvei strain PCM 1190 lipopolysaccharide.

The structure of the O-specific side-chain of the lipopolysaccharide of Hafnia alvei strain PCM 1190 has been investigated. Methylation analysis, partial acid hydrolysis, Smith degradation, NMR spectroscopy, MALDI-TOF, and FAB mass spectrometry in combination with collision-induced-decomposition MS/MS were the principal methods used. It was concluded that the polysaccharide is composed of heptasaccharide repeating units having the following structure: [formula: see text] Only 80% of the repeating units are complete, whereas 20% of them are lacking the alpha-D-glucopyranosyl group.

Structural studies of the O-specific chain and a core hexasaccharide of Hafnia alvei strain 1192 lipopolysaccharide.

The structure of the O-specific side-chain and a core hexasaccharide of the Hafnia alvei strain 1192 lipopolysaccharide has been investigated. Methylation analysis, NMR spectroscopy, MALDI-TOF spectrometry, and various specific chemical degradations were the principal methods used. It is concluded that the polysaccharide is composed of hexasaccharide repeating-units having the following structure which is partially O-acetylated in the 2-position of the --> 4)-alpha-D-Glc pA-(1-->(70%) and on different positions of the L-Rha residues (50%). [Formula: see text] The core hexasaccharide was found to have the following structure: [Formula: see text]