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PubMed2000

Protein spray-freeze drying. Effect of atomization conditions on particle size and stability.

PURPOSE: To investigate the effect of atomization conditions on particle size and stability of spray-freeze dried protein. METHODS: Atomization variables were explored for excipient-free (no zinc added) and zinc-complexed bovine serum albumin (BSA). Particle size was measured by laser diffraction light scattering following sonication in organic solvent containing poly(lactide-co-glycolide) (PLG). Powder surface area was determined from the N2 vapor sorption isotherm. Size-exclusion chromatography (SEC) was used to assess decrease in percent protein monomer. Fourier-transform infrared (FTIR) spectroscopy was employed to estimate protein secondary structure. PLG microspheres were made using a non-aqueous, cryogenic process and release of spray-freeze dried BSA was assessed in vitro. RESULTS: The most significant atomization parameter affecting particle size was the mass flow ratio (mass of atomization N2 relative to that for liquid feed). Particle size was inversely related to specific surface area and the amount of protein aggregates formed. Zinc-complexation reduced the specific surface area and stabilized the protein against aggregation. FTIR data indicated perturbations in secondary structure upon spray-freeze drying for both excipient-free and zinc-complexed protein. CONCLUSIONS: Upon sonication, spray-freeze dried protein powders exhibited friability, or susceptibility towards disintegration. For excipient-free protein, conditions where the mass flow ratio was > -0.3 yielded sub-micron powders with relatively large specific surface areas. Reduced particle size was also linked to a decrease in the percentage of protein monomer upon drying. This effect was ameliorated by zinc-complexation, via a mechanism involving reduction in specific surface area of the powder rather than stabilization of secondary structure. Reduction of protein particle size was beneficial in reducing the initial release (burst) of the protein encapsulated in PLG microspheres.

Biocompatible Materials↗

PubMed2001

Estuarine macrobenthic community structure in the Hawkesbury River, Australia: relationships with sediment physicochemical and anthropogenic parameters.

Macrobenthic community assemblage diversity and abundance were monitored on both Cowan and Berowra Creeks in the estuarine reaches of the Hawkesbury River, Sydney Australia during 1997-1998. Natural sediment physicochemical differences were assessed, along with low-level anthropogenic contaminants including copper, lead, zinc, phosphorus and nitrogen. Contaminant levels at all sites were below sediment guideline values for biological effects. Natural physicochemical sediment differences were the main determinants in species assemblage patterns among sites. Three groupings of sites with similar assemblages were observed during February 1998. Berowra Creek sites, which were higher in organic content and silt/clay (and thus metals and nutrients), higher in pH and lower in salinity, were similar in terms of contributions by the polychaetes Ceratoneresis aequisetis, Scoloplos normalis, the isopod Cyathura hakea and the bivalve mollusc Soletellina alba. Sites on upper Cowan Creek, higher in organic content, silt/clay (nutrients and metals) and lower in salinity, were similar and separated from other sites in terms of the polychaete Carazziella victoriensis and the gastropod mollusc Nassarius jonasii. Sites lower in Cowan Creek, tended to be higher in sand content, more saline and lower in organic content and thus nutrient and metal concentrations. These sites were similar in terms of contributions of the polychaete Sigalion bandaensis and the bivalve molluscs, Mysella vitrea and Tellina deltoidalis. The biotic assemblage patterns were not maintained temporally, suggesting the importance of monitoring over time to assess possible future impacts. Aggregating species data to the family level resulted in similar site discrimination. Site differences were less distinct at higher taxonomic levels and suggests future monitoring at the family level is sufficient to detect assemblage differences among sites. The results obtained represent the difficulty in detecting responses to low-level contamination at the community level, and provide a sound anticipatory baseline for the assessment of future possible anthropogenic disturbance in the Hawkesbury River.

Animals↗

PubMed2002

Pathomorphological and immunohistochemical analysis biopsy specimens from large bronchi of patients with pulmonary cancer.

Biopsy specimens from large bronchi of patients with central and peripheral pulmonary cancer were studied. Central cancer was associated with hyperplasia and dysplasia of the epithelium, hyperplasia of glandular compartment, and pronounced immunocompetent cell response. Peripheral cancer was characterized by predominance of atrophic and sclerotic changes, lymph flow disorders, and tendency to lymphoid aggregation. These data suggest that not only dysplasia, but also the combination of all structural changes typical of each form of pulmonary cancer should be considered as a morphological marker of enhanced risk of tumor development.

Adult↗

PubMed2001

Variable expression of activation-linked surface antigens on human mast cells in health and disease.

Mast cells (MC) are multipotent effector cells of the immune system. They contain an array of biologically active mediator substances in their granules. MC also express a number of functionally important cell surface antigens, including stem cell factor receptor (SCFR=kit=CD117), high affinity IgER (FcepsilonRI), or CSaR (CD88). Respective ligands can induce or promote degranulation, migration, or cytokine production. Other integral surface molecules can mediate adhesion or cell aggregation. Recent data suggest that a number of critical molecules are variably expressed on the surface of human MC. In fact, depending on the environment (organ), stage of cell maturation, type of disease, and other factors, MC express variable amounts of activation-linked antigens (CD25, CD63, CD69, CD88), cell recognition molecules (CD2, CD11, CD18, CD50, CD54), or cytokine receptors. At present, however, little is known about the mechanisms and regulation of expression of such antigens. The present article gives an overview of MC phenotypes in health and disease, and attempts to provide explanations for the phenotypic variability of MC.

Animals↗

PubMed1998

Comment on "Social contagion, adolescent sexual behavior, and pregnancy: a nonlinear dynamic EMOSA model".

The epidemic model of the onset of social activities (EMOSA model) for adolescent sexuality by J. L. Rodgers, D. C. Rowe, and M. Buster (1998) is examined. Strengths of the model include the nonlinear dynamic specification that seems reasonably realistic and the potential when used as a theoretical tool to generate new hypotheses for further testing at the individual level. Limitations include the lack of a well-developed statistical framework, the inability to include a variety of predictors to capture both social contagion and individual differences in the same model, and the focus on aggregate-level data. The EMOSA model for sexuality can be reparameterized to a hazard rate or an event history model that eliminates these shortcomings. Growth curve analysis represents another analytic alternative for the EMOSA model that also does not have these limitations.

Adolescent↗

PubMed1996

Major life events and minor stressors: identifying mediational links in the stress process.

Whether the relationship between major life events and distress is mediated through minor stressors was examined in three stress groups: those who (a) experienced the death of a spouse, (b) divorced, or (c) were the parent of a child with asthma. Each of these major stress groups was compared with a control group. Path analyses conducted by aggregating the data cross major stress groups indicated that major life events exert both a direct influence on distress and an indirect influence through minor stressors. On the other hand, the nature of the mediational relation linking major life events with psychological distress through minor stressors was found to vary as a function of the major life stress situation under consideration. Methodological and theoretical implications for the study of stress processes are discussed.

Adaptation, Psychological↗

PubMed2005

Seismological constraints on a possible plume root at the core-mantle boundary.

Recent seismological discoveries have indicated that the Earth's core-mantle boundary is far more complex than a simple boundary between the molten outer core and the silicate mantle. Instead, its structural complexities probably rival those of the Earth's crust. Some regions of the lowermost mantle have been observed to have seismic wave speed reductions of at least 10 per cent, which appear not to be global in extent. Here we present robust evidence for an 8.5-km-thick and approximately 50-km-wide pocket of dense, partially molten material at the core-mantle boundary east of Australia. Array analyses of an anomalous precursor to the reflected seismic wave ScP reveal compressional and shear-wave velocity reductions of 8 and 25 per cent, respectively, and a 10 per cent increase in density of the partially molten aggregate. Seismological data are incompatible with a basal layer composed of pure melt, and thus require a mechanism to prevent downward percolation of dense melt within the layer. This may be possible by trapping of melt by cumulus crystal growth following melt drainage from an anomalously hot overlying region of the lowermost mantle. This magmatic evolution and the resulting cumulate structure seem to be associated with overlying thermal instabilities, and thus may mark a root zone of an upwelling plume.

Journal Article↗

PubMed2007

The PharmGKB: integration, aggregation, and annotation of pharmacogenomic data and knowledge.

The Pharmacogenetics and Pharmacogenomics Knowledge Base, PharmGKB (http://www.pharmgkb.org), curates pharmacogenetic and pharmacogenomic information to generate knowledge concerning the relationships among genes, drugs, and diseases, and the effects of gene variation on these relationships. PharmGKB curators collect information on genotype-phenotype relationships both from the literature and from the deposition of primary research data into our database. Their goal is to catalyze pharmacogenetic and pharmacogenomic research.

Biomedical Research↗

PubMed2006

The relation of volume and outcome in trabeculectomy.

BACKGROUND/AIMS: Higher case volume has been associated with improved outcomes for a number of procedures. This study was designed to investigate whether this relationship existed for trabeculectomy. METHODS: The study was retrospective and conducted at an ophthalmic unit in the UK. All patients who had unenhanced trabeculectomy between 1996 and 2000 were identified. From their notes, the surgeon who performed the trabeculectomy was ascertained as were any unplanned interventions (eg conjunctival suturing, anterior chamber reformation, repeated attendances) within the first month of surgery. RESULTS: Two hundred and eleven trabeculectomies were performed over the study period. Twenty nine had unplanned interventions within the first postoperative month. Analysis of the data indicated that surgeons who performed less than eight operations per year had more complications than those who performed more than 10 per annum. This difference was only significant (chi(2)=4.0, P=0.045) when the data were aggregated. When separated per year, although not significant, the complication rate of the lower volume group was always higher than the group performing more than 10 per year. CONCLUSIONS: The results suggest that trabeculectomy can be added to the list of procedures in which larger case volume is associated with fewer early complications and potentially a better outcome. The findings, if replicated, tend to strengthen the argument for subspecialisation in glaucoma with its implications for training and revalidation.

Adult↗

PubMed2002

Mammalian Polo-like kinase 3 (Plk3) is a multifunctional protein involved in stress response pathways.

The Polo-like kinases (Plks) are a conserved family of kinases that contribute to cell cycle regulation, particularly in G2 and mitosis. In mammals, there are at least three members of the Plk family. Here we show that Plk3 is a stress response protein that becomes phosphorylated following DNA damage or mitotic spindle disruption. Phosphorylation enhances its kinase activity and is dependent upon ataxia telangiectasia-mutated (ATM) in the former case but not the latter. Plk3 associates with complexes of multiple sizes ranging from 150 to greater then 600 kDa. In its unphosphorylated form it elutes from a sizing column at about 400 kDa whereas it associates with complexes of 150 and 600 kDa when phosphorylated. Among the proteins with which it physically associates and utilizes, as substrates are Chk2 and P53. It phosphorylates Chk2 on a residue different from threonine 68 (Thr68), the principal target for ATM. While ATM is necessary for phosphorylation and activation of Chk2 in vivo, Plk3 seems to contribute to its full activation. In its phosphorylated form it also coelutes and forms a complex with unpolymerized tubulin. In aggregate, the data argue that Plk3 is a multifunctional protein that associates with multiple complexes and that contributes to response to stress incurred by DNA damage and mitotic spindle disruption, albeit via different pathways.

Ataxia Telangiectasia Mutated Proteins↗

PubMed2003

Urea signalling to immediate-early gene transcription in renal medullary cells requires transactivation of the epidermal growth factor receptor.

Signalling by physiological levels of urea (e.g. 200 mM) in cells of the mammalian renal medulla is reminiscent of activation of a receptor tyrosine kinase. The epidermal growth factor (EGF) receptor may be transactivated by a variety of G-protein-coupled receptors, primarily through metalloproteinase-dependent cleavage of a membrane-anchored EGF precursor. In the murine inner medullary collecting duct (mIMCD3) cell line, urea (200 mM) induced prompt (1-5 min) tyrosine phosphorylation of the EGF receptor. Pharmacological inhibition of EGF receptor kinase activity with AG1478 or PD153035 blocked urea-inducible transcription and expression of the immediate-early gene, Egr-1. AG1478 blocked, either fully or partially, other hallmarks of urea signalling including Elk-1 activation and extracellular signal-regulated kinase phosphorylation. EGF receptor kinase inhibition also blocked the cytoprotective effect of urea observed in the context of hypertonicity-inducible apoptosis. EGF receptor transactivation was likely to be attributable to metalloproteinase-dependent ectodomain shedding of an EGF receptor agonist because both specific and non-specific inhibitors of metalloproteinases blocked the urea effect. Heparin-binding EGF (HB-EGF), in particular, was implicated because the diphtheria toxin analogue and highly specific antagonist of HB-EGF, CRM197, also blocked urea-inducible transcription. In aggregate, these data indicate that signalling in response to urea in renal medullary cells requires EGF receptor transactivation, probably through autocrine action of HB-EGF.

Animals↗

PubMed2003

Identification of cofilin and LIM-domain-containing protein kinase 1 as novel interaction partners of 14-3-3 zeta.

Proteins of the 14-3-3 family have been implicated in various physiological processes, and are thought to function as adaptors in various signal transduction pathways. In addition, 14-3-3 proteins may contribute to the reorganization of the actin cytoskeleton by interacting with as yet unidentified actin-binding proteins. Here we show that the 14-3-3 zeta isoform interacts with both the actin-depolymerizing factor cofilin and its regulatory kinase, LIM (Lin-11/Isl-1/Mec-3)-domain-containing protein kinase 1 (LIMK1). In both yeast two-hybrid assays and glutathione S-transferase pull-down experiments, these proteins bound efficiently to 14-3-3 zeta. Deletion analysis revealed consensus 14-3-3 binding sites on both cofilin and LIMK1. Furthermore, the C-terminal region of 14-3-3 zeta inhibited the binding of cofilin to actin in co-sedimentation experiments. Upon co-transfection into COS-7 cells, 14-3-3 zeta-specific immunoreactivity was redistributed into characteristic LIMK1-induced actin aggregations. Our data are consistent with 14-3-3-protein-induced changes to the actin cytoskeleton resulting from interactions with cofilin and/or LIMK1.

14-3-3 Proteins↗

PubMed2002

Activation of nickel-specific CD4+ T lymphocytes in the absence of professional antigen-presenting cells.

Allergic contact dermatitis ensues from exaggerated T cell responses to haptens. Dendritic cells are required for the initiation of hapten sensitization, but they may not be necessary for disease expression. Here we investigated the antigen-presenting cell requirement of nickel-specific CD4+ lymphocytes isolated from the blood of six allergic individuals. A significant proportion (42 out of 121; 35%) of the T cell clones proliferated in vitro to nickel also in the absence of professional antigen-presenting cells, suggesting a direct T-T hapten presentation. Antigen-presenting-cell-independent T cells showed a predominant T helper 1 phenotype. Nickel recognition by these T cells was major histocompatibility complex class II restricted, not influenced by CD28 triggering, independent from their state of activation, and did not require processing. The capacity of this T cell subset to be directly stimulated by nickel was not due to unique antigen-presenting properties, as both antigen-presenting-cell-dependent and antigen-presenting-cell-independent clones displayed comparable levels of HLA-DR, CD80, and CD86, and were equally capable of presenting nickel to antigen-presenting-cell-independent clones. In contrast, neither T cell types activated antigen-presenting-cell-dependent T lymphocytes. T-T presentation induced T cell receptor downregulation, CD25, CD80, CD86, and HLA-DR upregulation, and interferon-gamma release, although to a lesser extent compared to those induced by dendritic cell-T presentation. Following T-T presentation, the clones did not undergo unresponsiveness and maintained the capacity to respond to dendritic cells pulsed with antigen. In aggregate, our data suggest that antigen-presenting-cell-independent T cell activation can effectively amplify hapten- specific immune responses.

Adult↗

PubMed1998

Effects on criminal violence of different beverage types and private and public drinking.

AIM: The purpose of the study is to analyse the relationship between homicide and assault rates on one hand, and various indicators of alcohol consumption on the other. The latter include private and public drinking with a further disaggregation into beverage-specific drinking. MEASUREMENTS: The data comprise aggregate time series for Sweden during the period 1956-94. The assault rate is measured as the number of police reported assaults (at all degrees of aggravation) per 100,000 inhabitants (15+). The homicide rate is measured as the number of homicides (where the victim was at least one year old) per 100,000 inhabitants (15+). Private consumption is gauged as retail sales of alcohol, and public consumption as on -premise sales (litres 100% per inhabitant, 15+). These two measures are disaggregated further into beverage specific sales (beer, spirits and wine). FINDINGS: According to the findings, there is a statistically significant relationship between the assault rate and a combined measure of on-premise sales of beer and spirits. The estimated relationship corresponds to an attributable fraction of about 40%. The homicide rate is significantly associated with retail sales of spirits; the attributable fraction is estimated at about 50%. Wine sales are not related to any of the two violence indicators. CONCLUSIONS: The findings suggest that the assault rate is related to consumption of beer and spirits in bars and restaurants, while the homicide rate is linked to consumption of spirits in private contexts. The findings, notably specific to Sweden during a certain time period, can be interpreted as the outcome of the interplay of a number of factors, including opportunity structure, social control and context of drinking, drinking patterns associated with the different beverage types and characteristics of the drinkers.

Alcohol Drinking↗

PubMedDate not supplied

Differential expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in ulcerative colitis and Crohn's disease.

Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is selectively expressed in the endothelial cells of intestinal mucosa and gut-associated lymphoid tissue (GALT). Engagement of MAdCAM-1 to its ligand, integrin alpha4beta7, on lymphocytes is associated with the homing of gut-associated lymphocytes to normal gastrointestinal tract and inflammation sites. The present study was designed to elucidate differences between Crohn's disease (CrD) and ulcerative colitis (UC) from the expression patterns of MAdCAM-1. Samples were taken from 40 patients with CrD and 24 patients with UC at surgical resection. Using frozen sections, immunohistochemistry was performed for MAdCAM-1, E-selectin and CD34. MAdCAM-1+ venules were abundant in inflamed mucosa in both UC and CrD. In contrast, clear differences were noted between UC and CrD in the inflammatory area in the ulcer base, that is, MAdCAM-1+ venules were more abundant in CrD than in UC (P < 0.001), while E-selectin was expressed equally in these venules in both diseases. Furthermore, CrD was characterized by the occurrence of MAdCAM-1+ venules in deeper layers of the intestinal tissue, mainly in lymphoid aggregates. Our data indicated more extensive expression of MAdCAM-1 in CrD, which could contribute not only to mucosal inflammation, but also to transmural inflammation in CrD.

Adult↗

PubMed2001

Evolution of percutaneous transluminal coronary angioplasty in Europe from 1992-1996.

BACKGROUND: The working group Coronary Circulation of the European Society of Cardiology has been conducting a yearly survey on coronary interventions in Europe. The purpose of this study is to present the evolution of percutaneous transluminal coronary angioplasty (PTCA) with epidemiological and economic implications. METHODS: Coronary interventions were polled by questionnaires distributed to all institutions performing cardiac catheterization. Aggregated country data of the years 1992-1996 on indication, type of procedure, technique, and outcome of coronary interventions were analysed. RESULTS: Population-adjusted coronary angiographies and PTCA procedures increased by 76% and by 105%, respectively. The Percentage of coronary stenting increased from zero to almost half of all procedures. Analysis per country groups reveals considerable variation, ranging, e.g. for PTCA in 1996 from 157 procedures per million population in a group of eastern countries to 1138 in a central European group. Relating total revascularization (R) to standardized death rate for ischaemic heart disease (SDR) and to gross domestic product (GDP), there was an increase from 1.0 to 1.8 R/SDR and 40 to 61 R/GDP in the central European group compared with an increase from 0.06 to 0.18 R/SDR and 43 to 85 R/GDP in the eastern group. CONCLUSIONS: An overall increase in PTCAs at an annual rate between 15 and 25% was observed. The wide variation in the use of PTCA in Europe appears to be dependent mostly on economic factors and national health care policies.

Angioplasty, Balloon, Coronary↗

PubMed2006

[Juvenile obesity and comorbidity type 2 diabetes mellitus (T2 DM) in Germany: development and cost-of-illness analysis].

PURPOSE: Obesity and type 2 diabetes mellitus (T2 DM) among children have increased in the last years and developed into a major public health problem in Germany. Obesity and T2 DM are important causes of morbidity among young people associated with high costs for the health system. The objective of this paper is to estimate the number of obese and diabetic children and adolescents and the associated economic burden of illness in Germany now (2003) and in the future. METHODS: Cost assessments of obesity in adulthood and studies of obese children in Germany are based on English and German scientific publications and internet sources. Cost calculations are based on the top-down approach and the prevalence method. Direct costs of illness are derived from aggregate statistical data (ICD 10: obesity E 65-68; T2 DM E 11) and various scientific publications and telephone interviews. Except for T2 DM, other comorbidities of obesity are neglected in this analysis. RESULTS: In 1999, 1.3 million children were overweight and 594,000 were obese in Germany. The highest prevalence of obesity was in children aged 14 to 17 years. The prevalence for overweight children has risen from 8.9 % to 15.7 % and for obese children from 10.1 % to 13.1 % over the period from 1994 to 1999/1998. Approximately 1 % of these were type 2 diabetics. During 2003, the mean annual direct costs of obesity were euro 44 million, with euro 36.4 million for rehabilitation, euro 3.6 million for hospital care and euro 3.9 million for special medical programs. The costs of juvenile T2 DM were euro 1.4 million (hospital care and rehabilitation). Mean costs per treated obese child added up to euro 3484.00 and to euro 8539.00 per treated obese child with T2 DM. The incremental costs are euro 2489.00 for obese children and euro 7544.00 for obese children with T2 DM compared to the average costs of illness of a child aged 5 to 20 years in Germany. Future annual attributable costs of obesity could be up to euro 6.4 million, 7.3-10.1 % of all obesity costs and for T2 DM up to euro 17.3 million (without T2 DM comorbidities) and euro 92.1 million (inclusive of all T2 DM comorbidities), 7.0-55.6 % of all obesity costs. CONCLUSIONS: Obesity and T2 DM are rapidly emerging as major disorders of childhood and adolescence and as important cost drivers for the health system. Due to the lack of data, there is a need for further research in the costs of obesity and T2 DM among children and for studies on suitable interventions to obviate a major public health crisis in Germany. The challenge for health policy is to identify effective and efficient prevention strategies.

Adolescent↗

PubMed2001

Comparison of patients' experiences during imaging tests of the colon.

BACKGROUND: Physical discomfort, anxiety, embarrassment, and other aspects of patient experience impact on future compliance for colonic imaging tests. Therefore, a prospective study was performed comparing patient experiences during air contrast barium enema (ACBE), flexible sigmoidoscopy, and colonoscopy. METHODS: Immediately after each procedure, patients completed a questionnaire assessing pretest anxiety, difficulty with preparation, pain, cramping, bloating, overall discomfort, loss of dignity, willingness to repeat the test, and overall satisfaction. A follow-up questionnaire was administered within 48 hours. Nurses and physicians also completed questionnaires to assess the provider impression of patient experience. RESULTS: Four hundred ten patients (80 ACBE, 202 sigmoidoscopy, 128 colonoscopy) were prospectively enrolled. Sigmoidoscopy caused more pain than ACBE (Odds ratio [OR] 2.64: 95% CI [1.63, 4.27]) or colonoscopy (OR 1.83: 95% CI [1.21, 2.77]). ACBE and colonoscopy did not differ in the degree of pain. Although overall satisfaction appeared to be similar for all tests, patients were less willing to repeat ACBE than sigmoidoscopy (OR 1.85: 95% CI [1.13, 3.02]) or colonoscopy (OR 1.82: 95% CI [1.07, 3.09]). Initial and follow-up pain ratings by patients were highly correlated (Spearman correlation 0.81); however, correlation of pain assessments between staff and patients was poor (Spearman correlation 0.48). CONCLUSIONS: Sigmoidoscopy was more painful than other colonic imaging modalities. Although ACBE and colonoscopy caused similar pain, patients were less willing to repeat ACBE. In aggregate, the data suggest that patients perceive colonoscopy as the most acceptable colonic imaging procedure. Better methods are required to allow staff to adequately assess discomfort experienced by patients during these procedures.

Adult↗