A Cross-Sectional and Longitudinal Analysis of Pre-Diagnostic Blood Plasma Biomarkers for Early Detection of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a major cause of cancer death that typically presents at an advanced stage. No reliable markers for early detection presently exist. The prominent tumor stroma represents a source of circulating biomarkers for use together with cancer cell-derived biomarkers for earlier PDAC diagnosis. CA19-9 and CEA (cancer cell-derived biomarkers), together with endostatin and collagen IV (stroma-derived) were examined alone, or together, by multivariable modelling, using pre-diagnostic plasma samples (n = 259 samples) from the Northern Sweden Health and Disease Study biobank. Serial samples were available for a subgroup of future patients. Marker efficacy for future PDAC case prediction (n = 154 future cases) was examined by both cross-sectional (ROC analysis) and longitudinal analyses. CA19-9 performed well at, and within, six months to diagnosis and multivariable modelling was not superior to CA19-9 alone in cross-sectional analysis. Within six months to diagnosis, CA19-9 (AUC = 0.92) outperformed the multivariable model (AUC = 0.81) at a cross-sectional level. At diagnosis, CA19-9 (AUC = 0.995) and the model (AUC = 0.977) performed similarly. Longitudinal analysis revealed increases in CA19-9 up to two years to diagnosis which indicates a window of opportunity for early detection of PDAC.

Geochemical and Dietary Drivers of Mercury Bioaccumulation in Estuarine Benthic Invertebrates

Sediments represent the main reservoir of mercury (Hg) in aquatic environments and may act as a source of Hg to aquatic food webs. Yet, accumulation routes of Hg from the sediment to benthic organisms are poorly constrained. We studied the bioaccumulation of inorganic and methylmercury (Hg^II and MeHg, respectively) from different geochemical pools of Hg into four groups of benthic invertebrates (amphipods, polychaetes, chironomids, and bivalves). The study was conducted using mesocosm experiments entailing the use of multiple isotopically enriched Hg tracers and simulation of estuarine systems with brackish water and sediment. We applied different loading regimes of nutrients and terrestrial organic matter and showed that the vertical localization and the chemical speciation of Hg^II and MeHg in the sediment, in combination with the diet composition of the invertebrates, consistently controlled the bioaccumulation of Hg^II and MeHg into the benthic organisms. Our results suggest a direct link between the concentration of MeHg in the pelagic planktonic food web and the concentration of MeHg in benthic amphipods and, to some extent, in bivalves. In contrast, the quantity of MeHg in benthic chironomids and polychaetes seems to be driven by MeHg accumulation via the benthic food web. Accounting for these geochemical and dietary drivers of Hg bioaccumulation in benthic invertebrates will be important to understand and predict Hg transfer between the benthic and the pelagic food web, under current and future environmental scenarios.

Acoustics modelling of open-cell foam materials from microstructure and constitutive properties

The dynamic relations for highly porous fibrous materials, having analytical expressions for dynamic viscous drag forces and oscillatory solid-to-fluid heat transfer, are now extended towards open-cell foam materials where the struts of the foam are considered to be primarily cylindrical except in the region of the joints. By also including analytical expressions for the stiffness of the foam cell, an entirely analytically-based model is presented for the acoustics of highly-porous, open-celled foam materials. This approach is extremely efficient, requiring only the mean cell size, mean strut diameter, and constitutive properties of the solid foam material and the surrounding viscous fluid as input. The acoustic performance prediction of not only isotropic foam cell designs, but also anisotropic ones may be performed rapidly and virtually, without the need for the determination of poroelastic material properties from existing material samples. The steps required for the development of the analytical foam-cell model are presented, along with the acoustic performance prediction of a typical Melamine foam cell, yielding very promising results in comparison against measurements. In order to understand the suitability of the cylindrical foam strut assumption, a viscous drag force comparison with foam struts having square and triangular cross-sectional profiles is also presented.

The use of panoramic images for identification of edentulous persons

The aim of this study was to determine if edentulous persons could be identified using panoramic images by: I) investigating the possibility of matching two panoramic radiographs of the same person obtained on two different occasions, II) determining what anatomical features are used as the base for matching, III) investigating if oral and maxillofacial radiologists (OMR) and dentists who were not oral and maxillofacial radiologists (NOMR) differed in their ability to match the images, and IV) determining if the time elapsed between the images affected the results or the confidence of the match. Panoramic image pairs from 19 patients obtained on two different occasions were included, plus 10 images from other edentulous patients. The time elapsed between the image pairs varied between 4 months and 6 years. Four OMR and four NOMR were asked to match the image pairs depicting the same patient. The participants marked each match as "certain", "likely", or "possible" and what anatomical structure they used for matching. The OMR group correctly matched 100% of the images and the NOMR group correctly matched 96%. The anatomy of the mandible was most often used for matching. The OMR group was more certain in their decisions than the NOMR group. The time elapsed between the examinations did not affect the result. In conclusion, panoramic images can be used to identify edentulous patients. Both OMR and NOMR could identify edentulous individuals when only panoramic radiographic images were available and the OMR were especially confident in the identification process.

An Investigation of the Clinical Use of a Single-Word Procedure to Assess Intelligibility (Swedish Test of Intelligibility for Children) and an Evaluation of the Validity and Reliability of the Intelligibility in Context Scale

Purpose Intelligibility is a core concept of speech-language pathology, central both to the assessment of speech disorders and to intervention in such disorders. One purpose of this study was to investigate the reliability and usability of a single-word assessment procedure, the Swedish Test of Intelligibility for Children (STI-CH), in a clinical setting. Another purpose was to investigate the validity and reliability of an assessment method designed to assess functional intelligibility: the Intelligibility in Context Scale (ICS). Method Thirty children aged 4;1-10;1 years;months were recruited from speech-language pathology clinics in Western Sweden. Each child's treating speech-language pathologist served as listener in the STI-CH assessment while the ICS was completed by each child's parents. External listeners (2 last-year speech-language pathology students) were used to assess the validity of the speech-language pathology. Results The mean duration of the test procedure for the STI-CH was about 19 min, and 57% of the test sessions were reported as difficult. There was a weak but statistically significant correlation between the results from the STI-CH and the ICS ( r = .40, p < .05), and both methods showed high reliability in terms of interlistener reliability (intraclass correlation exceeding .97) and internal consistency, respectively. Conclusions The STI-CH had high reliability and was time efficient but had some procedural problems. The ICS had moderate validity but high reliability. The STI-CH is promising for clinical use but needs to be developed further. The validity of the ICS can be discussed and needs to be further investigated.

Association between occurrence of urinary bladder cancer and treatment with statin medication

OBJECTIVE

The incidence of urinary bladder cancer (UBC) has increased in Sweden despite decreased smoking, indicating that other factors might be associated. The increased use of statin medication for elevated blood lipids might be one such influencing factor. The aim of the present study was to assess whether statins are afflicted with an increased incidence of UBC.

MATERIAL AND METHODS

Data from the Swedish National Register of Urinary Bladder Cancer, National Population Register, and Swedish Prescribed Drug Register were extracted. There were 22,936 patients with new diagnosed UBC between 2005 and 2014. Statin prescription was defined as any medication prescribed with the Anatomical Therapeutic Classification code C10A. For each patient, 10 control individuals were matched by age, gender, and living area, comprising 229,326 individuals. The Cochran-Mantel-Haenszel test was used to evaluate the hazards ratios.

RESULTS

Statins were more frequently used in patients with UBC (33.8%) than in controls (29.8%, p<0.0001). The use of statins was afflicted with a 23% increased odds ratio (OR) for UBC (OR 1.23 (1.19-1.27), p<0.001). Subgroup analyses showed that an increased OR was found in non-muscle invasive UBC only. There was a tendency that OR was stronger for men and for younger patients. Limitations include its retrospective register-based design and potential risk of bias of confounding factors, such as smoking and body mass index.

CONCLUSION

This nationwide register study suggests an association between the occurrence of UBC and patients using statins. The association was found in patients with non-muscle invasive disease only. Confounding factors, such as smoking, cannot be overruled.

Statin consumption as a risk factor for developing colorectal cancer: a retrospective case study

BACKGROUND

Statins are the backbone of lipid-lowering therapy and are among the most commonly prescribed drugs in the elderly population in Sweden today. Colorectal cancer is the second most common cancer in men and women, after prostate and breast cancer, respectively, with a median age of 72 years at diagnosis. Statins induce mitochondrial damage leading to accumulation of reactive oxygen species in the cell. Reactive oxygen species can cause mutations in mitochondrial as well as nuclear DNA leading to the development of cancer. Our hypothesis was that statins increase the risk for colorectal cancer.

METHODS

A case study was performed on consecutive cases of colorectal cancer diagnosed at Norrlands University Hospital (NUS) in Umeå between 2012 and 2015 (n = 325). Patients diagnosed with diabetes mellitus type II (DM II n = 65) were excluded in the primary endpoint analysis (occurrence of colorectal cancer). As control, three databases were used to create an age-matched population in order to calculate the proportion of inhabitants using statins in the county of Västerbotten, Sweden. A secondary endpoint was cancer-specific survival among our study group of colorectal cancer patients, including those with DM II, investigating whether there was a difference if the patient was a 'recent' statin user or not at the time of diagnosis.

RESULTS

Statin use at the time of colorectal cancer diagnosis in the study group was 23.8%. The corresponding figure in an age-matched population in Västerbotten was 24.6%. Using a one-proportional one-sided z test, there was no significant difference between these (23.8%, 95% CI 18.6-29.0%, p = 0.601). When comparing groups 20-64 years of age, the difference was greater with recent statin use in 17.8% in the study population and 11.9% in Västerbotten (17.8%, 95% CI 9.0-26.6%, p = 0.059). When considering cancer-specific survival, no significant difference in survival was seen when comparing 'former/never' statin users as reference category with 'recent' users diagnosed with colorectal cancer (HR 1.39, 95% CI 0.89-2.16).

CONCLUSIONS

No significant increase in risk for developing colorectal cancer among patients (type II diabetics excluded) medicated with statins was found. We found no correlation between 'recent' statin use at the time of diagnosis and cancer-specific survival.

Terrestrial discharges mediate trophic shifts and enhance methylmercury accumulation in estuarine biota

The input of mercury (Hg) to ecosystems is estimated to have increased two- to fivefold during the industrial era, and Hg accumulates in aquatic biota as neurotoxic methylmercury (MeHg). Escalating anthropogenic land use and climate change are expected to alter the input rates of terrestrial natural organic matter (NOM) and nutrients to aquatic ecosystems. For example, climate change has been projected to induce 10 to 50% runoff increases for large coastal regions globally. A major knowledge gap is the potential effects on MeHg exposure to biota following these ecosystem changes. We monitored the fate of five enriched Hg isotope tracers added to mesocosm scale estuarine model ecosystems subjected to varying loading rates of nutrients and terrestrial NOM. We demonstrate that increased terrestrial NOM input to the pelagic zone can enhance the MeHg bioaccumulation factor in zooplankton by a factor of 2 to 7 by inducing a shift in the pelagic food web from autotrophic to heterotrophic. The terrestrial NOM input also enhanced the retention of MeHg in the water column by up to a factor of 2, resulting in further increased MeHg exposure to pelagic biota. Using mercury mass balance calculations, we predict that MeHg concentration in zooplankton can increase by a factor of 3 to 6 in coastal areas following scenarios with 15 to 30% increased terrestrial runoff. The results demonstrate the importance of incorporating the impact of climate-induced changes in food web structure on MeHg bioaccumulation in future biogeochemical cycling models and risk assessments of Hg.

Effects of Nutrient Loading and Mercury Chemical Speciation on the Formation and Degradation of Methylmercury in Estuarine Sediment

Net formation of methylmercury (MeHg) in sediments is known to be affected by the availability of inorganic divalent mercury (Hg(II)) and by the activities of Hg(II) methylating and MeHg demethylating bacteria. Enhanced autochthonous organic matter deposition to the benthic zone, following increased loading of nutrients to the pelagic zone, has been suggested to increase the activity of Hg(II) methylating bacteria and thus the rate of net methylation. However, the impact of increased nutrient loading on the biogeochemistry of mercury (Hg) is challenging to predict as different geochemical pools of Hg may respond differently to enhanced bacterial activities. Here, we investigate the combined effects of nutrient (N and P) supply to the pelagic zone and the chemical speciation of Hg(II) and of MeHg on MeHg formation and degradation in a brackish sediment-water mesocosm model ecosystem. By use of Hg isotope tracers added in situ to the mesocosms or ex situ in incubation experiments, we show that the MeHg formation rate increased with nutrient loading only for Hg(II) tracers with a high availability for methylation. Tracers with low availability did not respond significantly to nutrient loading. Thus, both microbial activity (stimulated indirectly through plankton biomass production by nutrient loading) and Hg(II) chemical speciation were found to control the MeHg formation rate in marine sediments.

Can humic water discharge counteract eutrophication in coastal waters?

A common and established view is that increased inputs of nutrients to the sea, for example via river flooding, will cause eutrophication and phytoplankton blooms in coastal areas. We here show that this concept may be questioned in certain scenarios. Climate change has been predicted to cause increased inflow of freshwater to coastal areas in northern Europe. River waters in these areas are often brown from the presence of high concentrations of allochthonous dissolved organic carbon (humic carbon), in addition to nitrogen and phosphorus. In this study we investigated whether increased inputs of humic carbon can change the structure and production of the pelagic food web in the recipient seawater. In a mesocosm experiment unfiltered seawater from the northern Baltic Sea was fertilized with inorganic nutrients and humic carbon (CNP), and only with inorganic nutrients (NP). The system responded differently to the humic carbon addition. In NP treatments bacterial, phytoplankton and zooplankton production increased and the systems turned net autotrophic, whereas the CNP-treatment only bacterial and zooplankton production increased driving the system to net heterotrophy. The size-structure of the food web showed large variations in the different treatments. In the enriched NP treatments the phytoplankton community was dominated by filamentous >20 µm algae, while in the CNP treatments the phytoplankton was dominated by picocyanobacteria <5 µm. Our results suggest that climate change scenarios, resulting in increased humic-rich river inflow, may counteract eutrophication in coastal waters, leading to a promotion of the microbial food web and other heterotrophic organisms, driving the recipient coastal waters to net-heterotrophy.

Mercury methylation rates for geochemically relevant Hg(II) species in sediments

Monomethylmercury (MeHg) in fish from freshwater, estuarine, and marine environments is a major global environmental issue. Mercury levels in biota are mainly controlled by the methylation of inorganic mercuric mercury (Hg(II)) to MeHg in water, sediments, and soils. There is, however, a knowledge gap concerning the mechanisms and rates of methylation of specific geochemical Hg(II) species. Such information is crucial for a better understanding of variations in MeHg concentrations among ecosystems and, in particular, for predicting the outcome of currently proposed measures to mitigate mercury emissions and reduce MeHg concentrations in fish. To fill this knowledge gap we propose an experimental approach using Hg(II) isotope tracers, with defined and geochemically important adsorbed and solid Hg(II) forms in sediments, to study MeHg formation. We report Hg(II) methylation rate constants, k(m), in estuarine sediments which span over 2 orders of magnitude depending on chemical form of added tracer: metacinnabar (β-(201)HgS(s)) < cinnabar (α-(199)HgS(s)) < Hg(II) reacted with mackinawite (≡FeS-(202)Hg(II)) < Hg(II) bonded to natural organic matter (NOM-(196)Hg(II)) < a typical aqueous tracer ((198)Hg(NO(3))(2)(aq)). We conclude that a combination of thermodynamic and kinetic effects of Hg(II) solid-phase dissolution and surface desorption control the Hg(II) methylation rate in sediments and cause the large observed differences in k(m)-values. The selection of relevant solid-phase and surface-adsorbed Hg(II) tracers will therefore be crucial to achieving biogeochemically accurate estimates of ambient Hg(II) methylation rates.

Hyperaminoaciduria in mild phosphate diabetes in adults

Quantitative urinary amino acid excretion has been studied in 23 adult patients with mild phosphate diabetes (MPD), in 22 adult control patients with various renal disorders and in 15 children, 7--19 years old, with atopic disorders (normal controls). Statistically significant increases in urinary excretion of glutamine (p < 0.01), glycine (p < 0.01) and cystine (p < 0.05) were found in the MPD patients compared to the normal controls. The urinary excretion of glutamine was significantly increased while the increases in cystine and glycine excretions were non-significant when MPD patients were compared to the control patients. In addition to clinical signs and analyses of plasma and urinary phosphate, a quantitative evaluation of urinary amino acids might be a tool in the diagnosis of MPD. The significance of the increased urinary amino acid excretion in MPD is discussed.

Mild phosphate diabetes in adults

Phosphate diabetes has been considered as rare and to occur almost exclusively in children. Upon examination of adult patients with rheumatic or kidney diseases it has, however, been found that the combination of hypophosphataemia and hyperphosphaturia is not so rare. This paper deals with 24 adult patients of this type, whom we have found during 6 months. Their mean serum phosphorus concentration was 0.7 mmol/l (range 0.5--0.8). Mean phosphate clearance was 31 ml/min/1.73 m2 (range 16--51). The diagnoses were myalgia, dorsalgia (n = 7), papillitis calcificans (n = 5), prostatitis or prostate accretions (n = 4), dizziness (n = 2), kidney stones, tubular defect, interstitial nephritis, medullary sponge kidney (1 case each), two patients had transplanted kidneys. Asthenia was a common additional diagnosis. The patients' complaints have been pain in the muscles, joints, bones (18 cases), tiredness (10 cases), dizziness (8 cases), shakyness, numbness, burning sensation (7 cases), tenderness in the muscles and bones ("the princess-on-the-pea syndrome") (7 cases). The most common findings upon examination were bone tenderness (13 cases), reduced manual power (8 cases), positive Romberg test (3 cases), slight muscle atrophy (2 cases), waddling gait (2 cases). The most common findings encountered in the laboratory, besides hypophosphataemia and hyperphosphaturia, were high pH in the urine, hyperaminoaciduria, and phosphate crystals in dried urine.

Stability and fibril formation properties of human and fish transthyretin, and of the Escherichia coli transthyretin-related protein

Human transthyretin (hTTR) is one of several proteins known to cause amyloid disease. Conformational changes in its native structure result in aggregation of the protein, leading to insoluble amyloid fibrils. The transthyretin (TTR)-related proteins comprise a protein family of 5-hydroxyisourate hydrolases with structural similarity to TTR. In this study, we tested the amyloidogenic properties, if any, of sea bream TTR (sbTTR) and Escherichia coli transthyretin-related protein (ecTRP), which share 52% and 30% sequence identity, respectively, with hTTR. We obtained filamentous structures from all three proteins under various conditions, but, interestingly, different structures displayed different tinctorial properties. hTTR and sbTTR formed thin, curved fibrils at low pH (pH 2-3) that bound thioflavin-T (thioflavin-T-positive) but did not stain with Congo Red (CR) (CR-negative). Aggregates formed at the slightly higher pH of 4.0-5.5 had different morphology, displaying predominantly amorphous structures. CR-positive material of hTTR was found in this material, in agreement with previous results. ecTRP remained soluble at pH 2-12 at ambient temperatures. By raising of the temperature, fibril formation could be induced at neutral pH in all three proteins. Most of these temperature-induced fibrils were thicker and straighter than the in vitro fibrils seen at low pH. In other words, the temperature-induced fibrils were more similar to fibrils seen in vivo. The melting temperature of ecTRP was 66.7 degrees C. This is approximately 30 degrees C lower than the melting temperatures of sbTTR and hTTR. Information from the crystal structures was used to identify possible explanations for the reduced thermostability of ecTRP.

Hormone affinity and fibril formation of piscine transthyretin: the role of the N-terminal

Transthyretin (TTR) transports thyroid hormones (THs), thyroxine (T4) and triiodothyronine (T3) in the blood of vertebrates. TH-binding sites are highly conserved in vertebrate TTR, however, piscine TTR has a longer N-terminus which is thought to influence TH-binding affinity and may influence TTR stability. We produced recombinant wild type sea bream TTR (sbTTRWT) plus two mutants in which 6 (sbTTRM6) and 12 (sbTTRM12) N-terminal residues were removed. Ligand-binding studies revealed similar affinities for T3 (Kd=10.6+/-1.7nM) and T4 (Kd=9.8+/-0.97nM) binding to sbTTRWT. Affinity for THs was unaltered in sbTTRM12 but sbTTRM6 had poorer affinity for T4 (Kd=252.3+/-15.8nM) implying that some residues in the N-terminus can influence T4 binding. sbTTRM6 inhibited acid-mediated fibril formation in vitro as shown by fluorometric measurements using thioflavine T. In contrast, fibril formation by sbTTRM12 was significant, probably due to decreased stability of the tetramer. Such studies also suggested that sbTTRWT is more resistant to fibril formation than human TTR.

Addressable molecular node assembly--high information density DNA nanostructures

The inherent self-assembly properties of DNA make it ideal in nanotechnology. We present a fully addressable DNA nanostructure with the smallest possible unit cell, a hexagon with a side-length of only 3.4 nm.(2,3) Using novel three-way oligonucleotides, where each side has a unique double-stranded DNA sequence that can be assigned a specific address, we will build a non-repetitive two-dimensional grid.

The transthyretin-related protein: structural investigation of a novel protein family

The transthyretin-related protein (TRP) family comprises proteins predicted to be structurally related to the homotetrameric transport protein transthyretin (TTR). The function of TRPs is not yet fully established, but recent data suggest that they are involved in purine catabolism. We have determined the three-dimensional structure of the Escherichia coli TRP in two crystal forms; one at 1.65 A resolution in the presence of zinc, and the other at 2.1 A resolution in the presence of zinc and bromide. The structures revealed five zinc-ion-binding sites per monomer. Of these, the zinc ions bound at sites I and II are coordinated in tetrahedral geometries to the side chains of residues His9, His96, His98, Ser114, and three water molecules at the putative ligand-binding site. Of these four residues, His9, His98, and Ser114 are conserved. His9 and His98 bind the central zinc (site I) together with two water molecules. The side chain of His98 also binds to the zinc ion at site II. Bromide ions bind at site I only, replacing one of the water molecules coordinated to the zinc ion. The C-terminal four amino acid sequence motif Y-[RK]-G-[ST] constitutes the signature sequence of the TRP family. Two Tyr111 residues form direct hydrogen bonds to each other over the tetramer interface at the area, which in TTR constitutes the rear part of its thyroxine-binding channel. The putative substrate/ligand-binding channel of TRP is consequently shallower and broader than its counterpart in TTR.

High resolution crystal structures of piscine transthyretin reveal different binding modes for triiodothyronine and thyroxine

Transthyretin (TTR) is an extracellular transport protein involved in the distribution of thyroid hormones and vitamin A. So far, TTR has only been found in vertebrates, of which piscine TTR displays the lowest sequence identity with human TTR (47%). Human and piscine TTR bind both thyroid hormones 3,5,3'-triiodo-l-thyronine (T(3)) and 3,5,3',5'-tetraiodo-l-thyronine (thyroxine, T(4)). Human TTR has higher affinity for T(4) than T(3), whereas the reverse holds for piscine TTR. X-ray structures of Sparus aurata (sea bream) TTR have been determined as the apo-protein at 1.75 A resolution and bound to ligands T(3) and T(4), both at 1.9 A resolution. The apo structure is similar to human TTR with structural changes only at beta-strand D. This strand forms an extended loop conformation similar to the one in chicken TTR. The piscine TTR.T(4) complex shows the T(4)-binding site to be similar but not identical to human TTR, whereas the TTR.T(3) complex shows the I3' halogen situated at the site normally occupied by the hydroxyl group of T(4). The significantly wider entrance of the hormone-binding channel in sea bream TTR, in combination with its narrower cavity, provides a structural explanation for the different binding affinities of human and piscine TTR to T(3) and T(4).

The transthyretin-related protein family

A number of proteins related to the homotetrameric transport protein transthyretin (TTR) forms a highly conserved protein family, which we present in an integrated analysis of data from different sources combined with an initial biochemical characterization. Homologues of the transthyretin-related protein (TRP) can be found in a wide range of species including bacteria, plants and animals, whereas transthyretins have so far only been identified in vertebrates. A multiple sequence alignment of 49 TRP sequences from 47 species to TTR suggests that the tertiary and quaternary features of the three-dimensional structure are most likely preserved. Interestingly, while some of the TRP orthologues show as little as 30% identity, the residues at the putative ligand-binding site are almost entirely conserved. RT/PCR analysis in Caenorhabditis elegans confirms that one TRP gene is transcribed, spliced and predominantly expressed in the worm, which suggests that at least one of the two C. elegans TRP genes encodes a functional protein. We used double-stranded RNA-mediated interference techniques in order to determine the loss-of-function phenotype for the two TRP genes in C. elegans but detected no apparent phenotype. The cloning and initial characterization of purified TRP from Escherichia coli reveals that, while still forming a homotetramer, this protein does not recognize thyroid hormones that are the natural ligands of TTR. The ligand for TRP is not known; however, genomic data support a functional role involving purine catabolism especially linked to urate oxidase (uricase) activity.

Enamel matrix derivative promotes reparative processes in the dental pulp

During odontogenesis, amelogenins from the preameloblasts are translocated to differentiating odontoblasts in the dental papilla, suggesting that amelogenins may be associated with odontoblast changes during development. In the present study, we have explored the effects of enamel matrix derivative (EMD) on the healing of a pulpal wound. Coronal pulp tissue of permanent maxillary premolars of miniature swine were exposed through buccal class V cavities. The exposed pulp was capped with EMD. The contralateral teeth served as controls and were capped with a calcium hydroxide paste (Dycal). The cavities were sealed with glass-ionomer cement. After 2 and 4 weeks, the histology of the teeth was analyzed. In the EMD-treated teeth, large amounts of newly formed dentin-like hard tissue with associated formative cells outlined the pulpal wound separating the cavity area from the remaining pulp tissue. Inflammatory cells were present in the wound area but not subjacent to the newly formed hard tissue. Morphometric analysis showed that the amount of hard tissue formed in EMD-treated teeth was more than twice that of the calcium-hydroxide-treated control teeth (p < 0.001), suggesting that EMD is capable of promoting reparative processes in the wounded pulp more strongly than is calcium hydroxide.

Autocrine growth factors in human periodontal ligament cells cultured on enamel matrix derivative

OBJECTIVE

Enamel extracellular matrix proteins in the form of the enamel matrix derivative EMDOGAIN (EMD) have been successfully employed to mimic natural cementogenesis to restore fully functional periodontal ligament, cementum and alveolar bone in patients with severe periodontitis. When applied to denuded root surfaces EMD forms a matrix that locally facilitates regenerative responses in the adjacent periodontal tissues. The cellular mechanism(s), e.g. autocrine growth factors, extracellular matrix synthesis and cell growth, underlying PDL regeneration with EMD is however poorly investigated.

MATERIAL AND METHODS

Human periodontal ligament (PDL) cells were cultured on EMD and monitored for cellular attachment rate, proliferation, DNA replication and metabolism. Furthermore, intracellular cyclic-AMP levels and autocrine production of selected growth factors were monitored by immunological assays. Controls included PDL and epithelial cells in parallel cultures.

RESULTS

PDL cell attachment rate, growth and metabolism were all significantly increased when EMD was present in cultures. Also, cells exposed to EMD showed increased intracellular cAMP signalling and autocrine production of TGF-beta1, IL-6 and PDGF AB when compared to controls. Epithelial cells increased cAMP and PDGF AB secretion when EMD was present, but proliferation and growth were inhibited.

CONCLUSION

Cultured PDL cells exposed to EMD increase attachment rate, growth rate and metabolism, and subsequently release several growth factors into the medium. The cellular interaction with EMD generates an intracellular cAMP signal, after which cells secrete TGF-beta1, IL-6 and PDGF AB. Epithelial cell growth however, is inhibited by the same signal. This suggest that EMD favours mesenchymal cell growth over epithelium, and that autocrine growth factors released by PDL cells exposed to EMD contribute to periodontal healing and regeneration in a process mimicking natural root development.

Reversal of meconium inhibition of pulmonary surfactant by ferric chloride, copper chloride, and acetic acid

Meconium inhibits pulmonary surfactant function. We investigated the in vitro effect of meconium on three different commercial surfactants. The dynamic surface properties of these surfactants were evaluated at the concentration of 5 mg/ml with a pulsating bubble system. The inhibitory effect of 2.75 mg/ml meconium was significantly less on Alveofact than on Curosurf and Survanta. Ferric chloride and copper chloride completely reversed the inhibitory effect of meconium. Meconium also prevented effective spreading of surfactant in a Wilhelmy balance system, and this inhibitory effect was counteracted by addition of ferric chloride. Image analysis of Curosurf demonstrated that meconium reduced the total number of microbubbles in 15 light-microscopic fields (4.35 mm(2)) from 1,748 +/- 481 to 180 +/- 166. Ferric chloride restored the number of microbubbles. Addition of ferric chloride or copper chloride to surfactant/meconium lowers pH, and pH adjustment by acetic acid also reversed the inhibitory effect of meconium. Together with the fact that the iron-chelator deferoxamine did not attenuate the effect of ferric chloride this suggests that the observed contrainhibition is caused by lowering of pH, and that meconium inhibition of surfactant is pH-dependent. Lowering pH from 6.2 to 5-5.5 abolished the inhibitory effects of meconium on surfactant. Inhibition of 2.5 mg/ml of Curosurf with plasma could also be reversed by increasing amounts of ferric chloride. We conclude that the inhibitory effect of meconium on surfactant in vitro can be abolished by addition of ferric chloride, copper chloride, or acetic acid.

Factor analysis of the Zung Self-Rating Depression Scale in a large ambulatory oncology sample

Screening cancer patients for depression with self-report inventories presents clinical and methodological challenges. Many investigators separate "somatic" from "cognitive" symptoms when adapting such measures to oncology settings. However, this practice has rarely been empirically validated through factor-analytic studies. The following study describes a factor analysis of the Zung Self-Rating Depression Scale (ZSDS) from a large ambulatory sample of cancer patients (N = 1,109). A four-factor solution emerged, consisting of a cognitive symptom factor, a manifest depressed mood factor, and two somatic factors (eating and non-eating related). These factors accounted for 20% (cognitive), 13% (mood), 8% (non-eating), and 7% (eating) of the variance on the Zung, respectively. The authors discuss the implications of these results as they pertain to screening cancer patients for depression.

The effect of immediate-hypersensitivity reactions on the level of SLPI, granulocyte elastase, alpha1-antitrypsin, and albumin in nasal secretions, by the method of unilateral antigen challenge

BACKGROUND

The aim of this paper was to investigate the role of SLPI in patients with allergic rhinitis. From this point of view, we also examined leukocyte elastase, alpha1-antitrypsin, and albumin. SLPI is an inhibitor of serine proteases such as leukocyte elastase, cathepsin G, and mast-cell chymase. Since chymase is considered to participate in mast-cell degranulation and histamine release, SLPI might act as a regulator of allergic reactions. Recent interest has been focused on leukocytes and allergy. Since SLPI is a strong inhibitor of leukocyte elastase, we also focused on the function of elastase in allergic rhinitis.

METHODS

We used the method of nasal lavage after unilateral nasal antigen challenge in atopic and healthy subjects. The ELISA quantified SLPI and elastase. Albumin and alpha1-antitrypsin were quantified by electroimmunoassay. Gel filtration was used to separate native SLPI from its complex with elastase.

RESULTS

There was a higher level of SLPI in lavage fluid from healthy subjects than from atopic patients. SLPI was increased on the contralateral side in atopic subjects after allergen challenge. The absence of increase in SLPI on the challenged side may be attributed to the increase in elastase and its binding to SLPI, which might have an effect on the immunoreactivity and interfere with the ELISA. It may then be assumed that there is an augmentation of SLPI on the challenged side as well. No increase was seen in healthy subjects. There was a higher concentration of elastase, alpha1-antitrypsin, and albumin before antigen challenge in atopic patients outside the pollen season than in healthy subjects. As expected, an increase was also seen in the challenged side exclusively in atopic subjects.

CONCLUSIONS

The lower concentration of SLPI in nasal lavage fluid among the atopic patients than the healthy subjects indicates damaged mucosa. Neural reflexes are involved in SLPI release since there was an increase even in the contralateral nostril. A higher level of elastase and albumin before allergen challenge suggests chronic inflammation in nasal mucosa outside the pollen season. Leukocyte recruitment takes place in response to IgE-mediated reactions, which are reflected in an increase in elastase in response to allergen challenge.

The subacromial impingement syndrome. A study of results of treatment with special emphasis on predictive factors and pain-generating mechanisms

Forty-two patients with subacromial impingement syndrome entered a randomized prospective study comparing open anterior acromioplasty with a physiotherapy regime. The criterion for a successful outcome of treatment was a reduction of the initial pain score of more than 50% using the visual analogue scale (VAS) technique. The evaluation was performed by an independent observer. At the 6-month follow-up, treatment in the surgical group had been successful in 12/21 (57%) patients versus 6/18 (33%) in the physiotherapy group. A one-year evaluation revealed 16/21 (76%) "successes" in the surgical group. A direct and unbiased comparison with the physiotherapy group was not possible at one year, since 13 patients chose surgery after initial physiotherapy. However, in "an intention to treat" analysis outcome at one year was significantly better in those randomized to surgery. We found two standardized, composite, active movements--the "Pour out of a Pot" manoeuvre requiring the emptying of a pot of water, and the "Hand in Neck" manoeuvre--to be of predictive value for the outcome of surgery. When combining three pain-related variables into a criterion for prediction of success, a sensitivity of 78% (p < 0.02) and a specificity of 90% (p < 0.03) were attained. We advance the hypothesis that pain in the impingement syndrome is mainly elicited by comparison of the subacromial bursa. In some patients a traction-responsive pain generator in the supraspinatus tendon may be present as well.

IgE-mediated histamine release from nasal mucosa is inhibited by SLPI (secretory leukocyte protease inhibitor) to the level of spontaneous release

The secretory leukocyte protease inhibitor (SLPI) is a low-molecular-weight inhibitor of proteases, such as elastase and cathepsin G which are released from leukocytes during phagocytosis. The purpose of this study was to determine whether or not SLPI is able to inhibit IgE-mediated histamine release. Nasal mucosa from 11 test subjects without atopic disposition was used for this in vitro study. We found that SLPI inhibited histamine release in a dose-dependent way but was without influence on the spontaneous release.

Production and secretion of pancreatic secretory trypsin inhibitor in normal human small intestine

The aim of this study was to prove the production and secretion of pancreatic secretory trypsin inhibitor (PSTI) in human small intestine. To achieve this we analyzed the content of immunoreactive PSTI (irPSTI) in rinsing fluid from isolated small intestine, using the urea method to estimate the volume of epithelial lining fluid recovered. IrPSTI, measured by an enzyme-linked, immunosorbent assay (ELISA), was present in both free and complexed form. The free PSTI showed intact biologic activity, binding trypsin in stable complexes. The complexed PSTI was dissociated on acidification. With the reverse transcriptase polymerase chain reaction (RT-PCR) and Southern blot hybridization, PSTI mRNA was demonstrated in the mucosa of the ileum. These findings indicate that PSTI is produced and secreted in the small intestinal epithelium and may be part of defence system in intestinal mucosa.

Leukocyte activation detected by increased plasma levels of inflammatory mediators in patients with ischemic cerebrovascular diseases

BACKGROUND AND PURPOSE

Leukocytes have been implicated in the development of ischemic atherosclerotic vascular diseases. In a prospective study we investigated whether the plasma concentrations of inflammatory mediators, ie, proteases and cytokines, as markers for systemic leukocyte activation, are increased in patients with acute ischemic cerebrovascular diseases.

METHODS

Using enzyme-linked immunosorbent assays, we measured the plasma levels of neutrophil gelatinase-associated lipocalin (NGAL), neutrophil proteinase 4 (NP4), tumor necrosis factor-alpha (TNF), and soluble TNF receptor protein-1 p55 (sTNFR-1) in 120 patients with acute ischemic cerebrovascular insult (72 with stroke and 48 with transient ischemic attack [TIA]) and in 35 age- and sex-matched healthy subjects.

RESULTS

Compared with the control group, plasma NGAL levels were higher in the stroke group (P < .0001) and the TIA group (P < .01); plasma NP4 levels were higher in the stroke group (P < .0001) and the TIA group (P < .01); and plasma sTNFR-1 levels were higher in the stroke group (P < .04). There was significant correlation between the plasma levels of fibrinogen and those of both sTNFR-1 (r = .32; P = .005) and NGAL (r = .40; P = .0001) and between the erythrocyte sedimentation rate and the plasma levels of both sTNFR-1 (r = .35; P = .001) and NGAL (r = .34; P = .002).

CONCLUSIONS

Our study demonstrated that markers for systemic leukocyte activation, ie, plasma levels of cytokines and proteases, were higher in patients with acute ischemic cerebrovascular disease than in healthy control subjects. Activated leukocytes and leukocytic mediators may have an important role in acute cerebrovascular ischemia and its consequences.

Release of cytokines and proteases from human peripheral blood mononuclear and polymorphonuclear cells following phagocytosis and LPS stimulation

Release and cellular contents of pro- and anti-inflammatory cytokines, neutrophilic elastase and secretory leukocyte proteinase inhibitor (SLPI) were measured with enzyme-linked immunosorbent assay in peripheral blood mono- and polymorphonuclear cells stimulated with preopsonized yeast cells or lipopolysaccharide. Tumour necrosis factor alpha (TNF alpha) was also measured with a bioassay. TNF alpha production and soluble TNF alpha receptor I (sTNF RI) were demonstrated in the environment of both cell populations. The bioassay indicated levels of TNF alpha far below those detected by ELISA. The overall secretion of cytokines and their inhibitors was found to favour an anti-inflammatory balance in the environment of the stimulated cells. The interleukin-1 receptor antagonist (IL1-ra), compared with interleukin-1 beta (IL-1 beta), dominated the secretions from both cell types with a 100- to 1000-fold excess respectively. Most of the translated IL-1 beta was not secreted but found associated with the cellular compartments. In contrast to lipopolysaccharide (LPS) stimulation, preopsonized yeast cells stimulated a massive release of elastase from neutrophil cells.

Release of Bacterial DNA by Marine Nanoflagellates, an Intermediate Step in Phosphorus Regeneration

The concentrations of dissolved DNA and nanoflagellates were found to covary during a study of diel dynamics of the microbial food web in the Adriatic Sea. This observation was further investigated in a continuous seawater culture when nanoflagellates were fed bacteria grown in filtered seawater. Analysis of dissolved organic phosphorus and dissolved DNA showed a sixfold increase of dissolved DNA in the presence of the nanoflagellates ( Ochromonas sp.). The amount of DNA released suggested that the majority of the consumed bacterial DNA was ejected. Phagotrophic nanoflagellates thus represent an important source of origin for dissolved DNA. The rate of breakdown of dissolved DNA and release of inorganic phosphorus in the pelagic ecosystem is suggested to be dependent on the ambient phosphate pool. In the P-limited northern Adriatic Sea, rapid degradation of the labelled DNA could be demonstrated, whereas the N-limited southern California bight water showed a much lower rate. Phosphorus originating from dissolved DNA was shown to be transferred mainly to organisms in the <3-μm-size fractions. On the basis of the C/P ratios, we suggest that a significant fraction of the phosphorus demand by the autotrophs may be sustained by the released DNA during stratified conditions. Thus, the nucleic acid-rich bacterial biomass grazed by protozoa plays an important role in the biogeochemical cycling of phosphorus in the marine environment.

Release of immunoreactive human neutrophil proteinase 4, normally and in peritonitis

A specific enzyme-linked immunoassay (ELISA) has been developed for the determination of neutrophil proteinase 4 (NP4) in human plasma/serum and tissue fluids. Comparison of the sequence for the first 20 N-terminal amino acids of NP4, neutrophil elastase and cathepsin G shows that NP4 is distinct from the other two proteases. However, all three show considerable homology. Neither elastase nor cathepsin G show any immunoreactivity when tested in the present ELISA. Normal human plasma contains about 38 micrograms/l of NP4, identified as alpha 1-proteinase inhibitor complexes. This represents about 50% of the total amount of NP4 released in plasma. The remaining 50% is bound by alpha 2-macroglobulin. Blood coagulation leads to a rapid release of NP4 from the leukocytes. Peritonitis is accompanied by a pronounced release of NP4, as shown by a three-to 10-fold increase of NP4 plasma levels and by the NP4 level in peritoneal exudates, which reaches about 40 mg/l in severe cases.

Immunochemical and immunohistochemical evaluation of lung permeability in ventilated newborn rabbits

These experiments were designed to quantify the vascular-to-alveolar leakage albumin in the neonatal lung and to analyze the distribution of leaking airspaces in the lung parenchyma. Immediately after delivery, newborn rabbits with gestational age 27-29 days received an intravenous injection of human albumin as a marker and were ventilated for 15 min with standardized tidal volume (10 ml/kg). After the period of ventilation the lungs were either lavaged via the airways or fixed for histological studies. The median amount of albumin in lung lavage fluid, determined by immunodiffusion, was 4.8% of the injected dose after 27 days, 1.3% after 28 days, and 0.4% after 29 days of gestation; it was inversely correlated with the compliance of the respiratory system (r = -0.78; p less than .001). Immunohistochemical examination of lung section revealed that the leak was not diffuse; even in animals with gestational age 27 days it involved only a median of 48% of total alveoli. The median amount of alveoli containing the label fell to 6% after 28 days and to 0% after 29 days gestation, correlating inversely with the compliance of the respiratory system (r = -0.53; p less than 0.01). We suggest that our experimental model is useful for histological demonstration of serum proteins leaking into the airpaces under experimental conditions and for evaluating the effect of therapeutic regiments on neonatal lung permeability.

The course of renal amyloidosis with uraemia

The course of uraemia in 47 patients with renal amyloidosis has been studied. The median survival with a S-creatinine of 150 mumol/l was approximately 18 months, but 15% survived for more than 3 years. Deterioration arose often suddenly and was of unclear cause. Approximately 25% of the patients improved for a while and the reason for this temporary improvement is also unclear. The unsteady course during the uraemia period for amyloidosis patients makes prognosis calculations very much less accurate than for patients with cystic kidneys.

[Intensive dynamic back exercises for patients with chronic low back pain. A controlled study]

The effect of intensive dynamic back extensor exercises for patients with chronic low back was investigated in a controlled clinical trial where the patients underwent a three months intensive training program a total 30 sessions. The 105 patients were divided into three groups: a treatment group, an alternative group which underwent 1/5 of the treatment group's exercise program per session, and an alternative group in which the treatment consisted of thermotherapy, massage and mild exercise. Regardless of whether the outcome of treatment is assessed qualitatively or quantitatively, a statistically significant, favourable difference was found between the results for the treatment group and those for the alternative groups. The therapy was found to be without risk, but patients with clinical signs of current lumbar nerve root compression or radiological signs of spondylolysis or halisteresis of the column were excluded from the study. The authors recommend the introduction of this form of treatment as a general offer in the primary and secondary health sector. Back exercises can advantageously be conducted in a group; thus, the resources required for this treatment do not differ significantly from those required for many of the other forms of treatment generally employed, which often require individual attention.

Clinical trial of intensive muscle training for chronic low back pain

105 patients who had chronic low back pain without clinical signs of lumbar nerve root compression or radiological evidence of spondylolysis or osteomalacia were randomised to three treatments: 30 sessions of intensive dynamic back extensor exercises over three months; a similar programme at one-fifth the exercise intensity; or one month of thermotherapy, massage, and mild exercises. The results consistently favoured intensive exercise, which had no adverse effects. Since these exercises can be conducted in groups, the intensive programme is no more costly than conventional strategies that require individual attention.

Hydralazine-induced relapsing polychondritis-like syndrome. Report of a case with severe chronic laryngeal complications

Relapsing polychondritis is a rare disease of uncertain etiology, characterized by inflammation of cartilage. Cartilage of the respiratory tract is engaged in more than half of all cases. Hydralazine-induced systemic lupus erythematosis (SLE) is a well known disease. Females who are slow acetylators and are HLA-DR4 positive when treated with hydralazine are at serious risk of contracting SLE syndrome. We describe here a woman, treated for 10 years with hydralazine, who was a slow acetylator and was HLA-DR4 positive and who presented with a relapsing polychondritis and ultimately required a permanent tracheostoma. To our knowledge, this is the first published case of relapsing polychondritis induced by hydralazine.