Can SLE classification rules be effectively applied to diagnose unclear SLE cases?

Objective The objective of this paper is to develop novel classification criteria to distinguish between unclear systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) cases. Methods A total of 205 variables from 111 SLE and 55 MCTD patients were evaluated to uncover unique molecular and clinical markers for each disease. Binomial logistic regressions (BLRs) were performed on currently used SLE and MCTD classification criteria sets to obtain six reduced models with power to discriminate between unclear SLE and MCTD patients that were confirmed by receiving operating characteristic (ROC) curve. Decision trees were employed to delineate novel classification rules to discriminate between unclear SLE and MCTD patients. Results SLE and MCTD patients exhibited contrasting molecular markers and clinical manifestations. Furthermore, reduced models highlighted SLE patients exhibiting prevalence of skin rashes and renal disease while MCTD cases show dominance of myositis and muscle weakness. Additionally decision tree analyses revealed a novel classification rule tailored to differentiate unclear SLE and MCTD patients (Lu-vs-M) with an overall accuracy of 88%. Conclusions Validation of our novel proposed classification rule (Lu-vs-M) includes novel contrasting characteristics (calcinosis, CPK elevated and anti-IgM reactivity for U1-70K, U1A and U1C) between SLE and MCTD patients and showed a 33% improvement in distinguishing these disorders when compared to currently used classification criteria sets. Pending additional validation, our novel classification rule is a promising method to distinguish between patients with unclear SLE and MCTD diagnosis.

Divergence in proteins, mitochondrial DNA, and reproductive compatibility across the isthmus of Panama.

It is widely believed that gene flow connected many shallow water populations of the Caribbean and eastern Pacific until the Panama seaway closed 3.0 to 3.5 million years ago. Measurements of biochemical and reproductive divergence for seven closely related, transisthmian pairs of snapping shrimps (Alpheus) indicate, however, that isolation was staggered rather than simultaneous. The four least divergent pairs provide the best estimate for rates of molecular divergence and speciation. Ecological, genetic, and geological data suggest that gene flow was disrupted for the remaining three pairs by environmental change several million years before the land barrier was complete.

Antibacterial and antibiofouling clay nanotube-silicone composite.

INTRODUCTION: Invasive medical devices are used in treating millions of patients each day. Bacterial adherence to their surface is an early step in biofilm formation that may lead to infection, health complications, longer hospital stays, and death. Prevention of bacterial adherence and biofilm development continues to be a major healthcare challenge. Accordingly, there is a pressing need to improve the anti-microbial properties of medical devices. MATERIALS AND METHODS: Polydimethylsiloxane (PDMS) was doped with halloysite nanotubes (HNTs), and the PDMS-HNT composite surfaces were coated with PDMS-b-polyethylene oxide (PEO) and antibacterials. The composite material properties were examined using SEM, energy dispersive spectroscopy, water contact angle measurements, tensile testing, UV-Vis spectroscopy, and thermal gravimetric analysis. The antibacterial potential of the PDMS-HNT composites was compared to commercial urinary catheters using cultures of E. coli and S. aureus. Fibrinogen adsorption studies were also performed on the PDMS-HNT-PEO composites. RESULTS: HNT addition increased drug load during solvent swelling without reducing material strength. The hydrophilic properties provided by PEO were maintained after HNT addition, and the composites displayed protein-repelling properties. Additionally, composites showed superiority over commercial catheters at inhibiting bacterial growth. CONCLUSION: PDMS-HNT composites showed superiority regarding their efficacy at inhibiting bacterial growth, in comparison to commercial antibacterial catheters. Our data suggest that PDMS-HNT composites have potential as a coating material for anti-bacterial invasive devices and in the prevention of institutional-acquired infections.

Assessing the impact of nutrient enrichment in estuaries: susceptibility to eutrophication.

The main aim of this study was to develop a generic tool for assessing risks and impacts of nutrient enrichment in estuaries. A simple model was developed to predict the magnitude of primary production by phytoplankton in different estuaries from nutrient input (total available nitrogen and/or phosphorus) and to determine likely trophic status. In the model, primary production is strongly influenced by water residence times and relative light regimes. The model indicates that estuaries with low and moderate light levels are the least likely to show a biological response to nutrient inputs. Estuaries with a good light regime are likely to be sensitive to nutrient enrichment, and to show similar responses, mediated only by site-specific geomorphological features. Nixon's scale was used to describe the relative trophic status of estuaries, and to set nutrient and chlorophyll thresholds for assessing trophic status. Estuaries identified as being eutrophic may not show any signs of eutrophication. Additional attributes need to be considered to assess negative impacts. Here, likely detriment to the oxygen regime was considered, but is most applicable to areas of restricted exchange. Factors which limit phytoplankton growth under high nutrient conditions (water residence times and/or light availability) may favour the growth of other primary producers, such as macrophytes, which may have a negative impact on other biological communities. The assessment tool was developed for estuaries in England and Wales, based on a simple 3-category typology determined by geomorphology and relative light levels. Nixon's scale needs to be validated for estuaries in England and Wales, once more data are available on light levels and primary production.

Culture and identification of Desulfovibrio spp. from corals infected by black band disease on Dominican and Florida Keys reefs.

Black band disease (BBD) of corals is characterized as a pathogenic microbial consortium composed of a wide variety of microorganisms. Together, many of these microorganisms contribute to an active sulfur cycle that produces anoxia and high levels of sulfide adjacent to the coral surface, conditions that are lethal to coral tissue. Sulfate-reducing bacteria, as sulfide producers, are an important component of the sulfur cycle and the black band community. Previous molecular survey studies have shown multiple Desulfovibrio species present in BBD but with limited consistency between bacterial species and infections. In this study we compared 16S rRNA gene sequences of sulfate-reducing bacteria selectively cultured from 6 BBD bands on 4 coral species, Diploria clivosa, D. strigosa, D. labyrinthiformes, and Siderastrea siderea, in the Florida Keys and Dominica. The 16S rRNA gene sequences were obtained through direct sequencing of PCR products or by cloning. A BLAST search revealed that 8 out of 10 cultures sequenced were highly homologous to Desulfovibrio sp. strain TBP-1, a strain originally isolated from marine sediment. Although the remaining 2 sequences were less homologous to Desulfovibrio sp. strain TBP-1, they did not match any other sulfate-reducing (or other) species in GenBank.

Comparison of selective attachment and growth of smooth muscle cells on gelatin- and fibronectin-coated micropatterns.

Tissue engineering research has been on going for many years, people are making all the effort to explore the cell functions in cellular level and even in molecular level. Making the cells functional in an in vitro environment is a preliminary goal for the implantation and repair of complicated tissues/organs. Fabricating artificial ECM to mimic the in vivo environment is an essential approach in tissue engineering. The work in this paper is to study how rat aorta smooth muscle cells (RASMCs) behave in two engineered cell culture scaffolds: gelatin- and fibronectin (FN)-coated micropatterns. The investigation on the initial attachment and further growth of SMCs cultured on gelatin- and FN-coated micropatterns was addressed. This study focused on both the characterization of gelatin and fibronectin assembly properties and cell responses to these two protein-coated micropatterns. Thin film patterns with gelatin and fibronectin coatings were fabricated on microscope glass slides using photolithography, electrostatic layer-by-layer self-assembly and lift-off (LbL-LO) technologies. In this work, the scaffolds were built up by commonly used polyelectrolyte materials and proteins through LbL process, containing cationic poly(diallyldimethylammonium chloride) (PDDA), poly(allylamine hydrochloride) (PAH), anionic poly(sodium 4-styrenesulfonate) (PSS), gelatin and fibronectin. The resulting polyelectrolyte thin films were characterized by contact angle (CA), quartz crystal microbalance (QCM), atomic force microscopy (AFM), and fluorescence microscopy. CA measurement shows the consistent hydrophylicity of gelatin surfaces in different number of layers with LbL deposition method. Different from our previous QCM measurement of gelatin, fibronectin does not show high electrostatic attraction to either positively or negatively charged polyelectrolytes, although it can be weakly assembled to both polyelectrolyte surfaces. AFM images show Gelatin- and FN-coated micropatterns are around 50-60 nm thick. RASMCs were cultured on these gelatin- and FN-coated micropatterns. It was observed that, for the cells cultured on gelatin-coated micropatterns, they initially landed on the gelatin-coated surface, not on the PDDA-coated surface in between. But further growth of the cells was affected by the shape of the patterns: strip pattern limited cell growth beyond the patterns, but square patterns could not. While, it was found interestingly, for the cells cultured on FN-coated micropatterns, SMCs initially landed on PDDA-coated surface, and then migrated to FN-coated both square and strip patterns. These findings indicate that both gelatin and fibronectin are adhesive proteins, but they have different effects on the initial attachment and later growth for SMCs.

Assessing the suitability of OSPAR EcoQOs for eutrophication vs ICES criteria for England and Wales.

This paper provides a preliminary evaluation of the suitability of OSPAR Ecological Quality objectives for eutrophication for coastal and offshore waters of England and Wales on the basis of ICES criteria. In principle, EcoQOs are easy to understand, but responses to nutrient enrichment are complex. Few studies provide unequivocal evidence of links between inputs and response. Monitoring is generally feasible and in place, but needs to be improved. The best EcoQO is winter nutrient concentrations. Chlorophyll concentrations are a good indicator in environments susceptible to nutrient enrichment. The EcoQO for zoobenthos/fish kills potentially meets all criteria for a good indicator; EcoQOs for phytoplankton indicator species, oxygen concentrations and zoobenthos changes do not. Greater emphasis needs to be placed on seasonal effects of nutrient inputs and phytoplankton response, natural susceptibility of different water bodies, differences between coastal and offshore environments, and developing longer time series of data.

Simple screening tests for the diagnosis of isolated clotting factor defects. With special reference to 'contact factor' defects.

Reagents may be prepared from normal plasma and used with the prothrombin time and partial thromboplastin time tests to distinguish isolated defects of factors I, II, VII, VIII, IX, X, XI, or XII.

Lack of consensus among experts on the choice of UV therapy for psoriasis.

CONTEXT: Each year tens of thousands of patients in the United States are treated with UV-B radiation or psoralen plus UV-A radiation (PUVA) for a variety of skin disorders. Although PUVA is generally considered more effective, it is also more toxic and more expensive. The degree of consensus among experts in prescribing these alternative treatments has not been quantified. OBJECTIVES: To quantify variation among specialty clinics in the type of ultraviolet therapy used to treat specific skin conditions and assess factors associated with the use of specific treatments. DESIGN: Survey conducted during two 2-week periods in the late fall of 1994 and early spring of 1995. SETTING: Thirty-nine specialty clinics in 17 US geographic areas in 14 states and Washington, DC. PARTICIPANTS: A total of 3401 patients treated with UV radiation one or more times. OUTCOME MEASURES: Type of UV therapy used and indications for treatment, age, sex, number of patients treated, and geographic location of each clinic. RESULTS: The proportion of patients at each center treated with PUVA ranged from 0% to 93% (mean, 41%). Clinic size and geographic location, demographic characteristics of the patients, and diagnosis did not explain these large intercenter differences. CONCLUSIONS: Among specialized clinics, there is little consistency in the use of alternative therapies, which differ substantially in safety and cost, but whose relative efficacy is not well quantified. There is a lack of consensus among experts about the circumstances in which the greater risks and costs of PUVA are outweighed by its possibly greater efficacy, especially in the treatment of psoriasis.

Lethal consequences of simulated solar radiation on the nematode Caenorhabditis elegans in the presence and absence of photosensitizers.

The partial destruction of the earth's protective ozone layer has raised concerns about the impact of increased UV radiation on the earth's biological systems. In this study, polychromatic light sources were employed to observe the biological responses of the soil nematode Caenorhabditis elegans to simulated solar UV. Using various filter combinations, action spectra were constructed that approximated those generated previously with mono-chromatic radiation. In both cases, a mutant strain (rad-3) progressively lost its hypersensitivity as shorter wave-lengths were filtered out. In addition, both wild type and radiation-sensitive (rad) mutants were irradiated with several combinations of filtered light sources in the presence and absence of two exogenous photosensitizers (ethidium bromide and bromodeoxyuridine). Treatment with either of the introduced photosensitizers increased photosensitivity to solar UV. Solar UV also induced a fluence-dependent reduction in fertility in wild-type animals. These experiments extend previous data and substantially expand our understanding of the biological responses of C. elegans to solar radiation.

Histological features and in-vitro proteoglycan synthesis in the rabbit craniomandibular joint disc.

The biomechanical properties of this disc depend upon the composition and organization of the extracellular matrix, in which the most important elements are collagen, proteoglycan composition, and the density and orientation of the collagen fibres. The disc is composed of two thickened bands connected by a thin intermediate zone and fibrous attachment regions. Immunohistochemical analysis with monoclonal antibodies to chondroitin-6-sulphate and keratan sulphate revealed a concentration of these cartilage-characteristic glycosaminoglycans surrounding rounded, cartilage-like cells in the bands. Cells were isolated from the cartilage-like band areas and from the fibrous-attachment regions and cultured in vitro. Labelled proteoglycans synthesized by the band cells were similar to those known to be synthesized by hyaline cartilage, but the attachment-region cells synthesized fibroblast-like proteoglycans.

The behaviour of collagen fibres in stress relaxation and stress distribution in the jaw-joint disc of rabbits.

The physical properties of the temporomandibular joint disc are largely attributable to its collagen fibre and proteoglycan composition and organization. Structural and stress relaxation data were obtained from the discs of six rabbits. Two stainless-steel balls, 4.8 mm dia, were used to load the disc surfaces in compression. Stress relaxation tests were performed at loads of 0.8-1.4 kg, and the disc was then placed in fixative while still in the loading apparatus in order to preserve its deformed state at equilibrium stress. After overnight fixation the discs were sectioned and assessed by means of a polarizing microscope with a rotating universal stage. This allowed measurement of three-dimensional changes in collagen fibre waviness and alignment as the result of loading. The data showed that despite significant stress relaxation and strains, only minor changes in fibre waviness and alignment occurred within the disc, reflecting its effectiveness as a tough but compliant structure, well suited to distribute load in the temporomandibular joint.

Morphologic, microscopic, and immunohistochemical investigations into the function of the primate TMJ disc.

The distribution and arrangement of extracellular matrix proteins were examined in the primate temporomandibular joint disc and posterior attachment using a combination of light microscopic, immunohistochemical, and biochemical techniques. The band areas of the disc contain a complex collagenous (type I) fiber network consisting of a mediolaterally directed fiber bundle system that interlaces or becomes continuous with an anteroposteriorly directed collagenous fiber array that runs through the intermediate zone. Thin, branching, elastic fibers are a significant component of the disc and are generally oriented parallel to the collagenous fiber network. Interfibrillar spaces in band areas contain numerous chondrocytes encased within a matrix that is rich in a high molecular weight, predominantly chondroitin-sulfate proteoglycan and type II collagen. The intermediate zone appears tendinous in its construction and is composed of anteroposteriorly oriented elastic and collagenous fibers, scattered chondrocytes, and reduced amounts of chondroitin-sulfate proteoglycan and type II collagen. The posterior attachment is composed of fibrocytes, larger caliber elastic fibers, loosely organized type I collagenous fibers, and low molecular weight dermatan-sulfate proteoglycan. These results indicate that the primate temporomandibular joint disc is a microheterogenous tissue with distinct regional specializations.

In vitro evaluation of chondrosarcoma cells and canine chondrocytes on layer-by-layer (LbL) self-assembled multilayer nanofilms.

Short-term cell-substrate interactions of two secondary chondrocyte cell lines (human chondrosarcoma cells, canine chondrocytes) with layer-by-layer self-assembled multilayer nanofilms were investigated for a better understanding of cellular-behaviour dependence on a number of nanofilm layers. Cell-substrate interactions were studied on polyelectrolyte multilayer nanofilms (PMNs) of eleven different biomaterials. Surface characterization of PMNs performed using AFM showed increasing surface roughness with increasing number of layers for most of the biomaterials. LDH-L and MTT assays were performed on chondrosarcoma cells and canine chondrocytes, respectively. A major observation was that 10-bilayer nanofilms exhibited lesser cytotoxicity towards human chondrosarcoma cells than their 5-bilayer counterparts. In the case of canine chondrocytes, BSA enhanced cell metabolic activity with increasing number of layers, underscoring the importance of the multilayer nanofilm architecture on cellular behaviour.

Proteoglycan synthesis by cells cultured from regions of the rabbit flexor tendon.

Rabbit flexor tendons have two distinct biomechanical regions: a compressional region which is characterized by chondrocyte-like cells and abundant matrix, and a tensional region which has a typical tendon morphology with elongated cells, sparse matrix and parallel bundles of collagen fibers. Tissue culture of these regions yields two distinct populations of cells. The compressional cells in vitro synthesize high molecular weight chondroitin sulfate proteoglycan, while the tensional cells synthesize a dermatan sulfate rich, low molecular weight proteoglycan. Immunohistochemical localization utilizing monoclonal antibodies confirms the localization of chondroitin sulfate and keratan sulfate in the compressional regions and its absence in tensional areas. These observations indicate that adult flexor tendon cells in culture continue to express their region-specific phenotypes.

Development of functional specializations within the maturing rabbit flexor digitorum profundus tendon.

Along its length, the rabbit flexor digitorum profundus (FDP) tendon exhibits two functionally specialized regions: classical tendon (CT) and fibrocartilage (FC). We examined their development in rabbits, ranging in age from newborn to nine-months postnatal, using a combination of light microscopic, immunohistochemical and biochemical techniques. There is little histodifferentiation in newborn tendon. Both regions are composed of thin collagenous fibers, numerous fibroblast-like cells and a low molecular weight dermatan-sulfate proteoglycan. Regional specialization has begun by two-weeks postnatal and by three-months postnatal, FC regions have been transformed into a true fibrocartilage characterized by a complex collagenous and elastic fiber network, numerous chondrocytes and a matrix rich in a high molecular weight predominantly chondroitin-sulfate proteoglycan and type II collagen. These features are elaborated between three and nine-months postnatal. CT regions undergo little substantial change during growth and maturation. The rabbit is born altricial and incapable of adult patterns of locomotion. We propose that the developmental expression of functional specializations within the FDP tendon is closely linked with the onset of different physical demands arising from the adoption of adult patterns of locomotion.

HIV-positive patients differ from HIV-negative patients in indications for and type of UV therapy used.

BACKGROUND: Treatments using UV, UVB, or oral psoralen and UVA (PUVA) have been advocated for the care of HIV-infected persons with skin diseases. Concerns about the safety of these treatments exist. OBJECTIVE: We attempted to determine the characteristics of HIV infected persons receiving UV therapy and establish the reasons for and type of treatment administered. METHODS: During two 2-week periods, we prospectively ascertained basic information on all patients treated at 40 phototherapy clinics and detailed clinical information on patients known to be infected with HIV. RESULTS: We identified 3716 persons receiving UV therapy, including 311 known to be infected with HIV. When compared with patients not known to be infected with HIV, HIV-positive patients were significantly more likely to be treated with UVB rather than PUVA and were more likely to be treated for pruritic conditions rather than psoriasis. CONCLUSION: There were great variations in the relative reliance on UVB and PUVA among centers. There appears to be no agreement as to which type of UV therapy is optimal for patients infected with HIV. Most patients known to the treating clinician to be HIV positive are in the advanced stages of HIV disease. The number of persons with less advanced HIV disease receiving treatment remains unquantified but may be even more clinically important.

An animal model for studying mechanisms in human temporomandibular joint disc derangement.

PURPOSE: A method for producing disc displacement is presented in which remodeling events in the disc and posterior attachment (PA) are similar to those occurring in patients suffering from disc displacement (DD). METHOD: Thirty-three adult New Zealand White rabbits were used in this study. A unilateral anterior DD was surgically induced in 18 animals. Six animals were sham operated and nine animals served as controls. RESULTS: Macroscopically, DD was associated with gross thickening of the posterior band (PB), shortening of the disc anteroposteriorly, flexure of the intermediate zone (IZ), and loss of the biconcave shape. Microscopically, dramatic internal structural changes were observed in displaced discs, including extensive collagenous fiber reorganization and changes in cell morphology associated with a generalized loss of metachromatic staining. As in humans, the disc displacement caused abnormal loading of the PA and remodeling of this tissue into a disc-like structure characterized by the appearance of coarse collagenous fiber bundles and scattered chondrocytes surrounded by a matrix-containing cartilage-like glycosaminoglycans (GAGs). CONCLUSION: These pathoanatomic changes bear a remarkable similarity to those described in human disc derangements and support the use of this method as an experimental model for the study of remodeling events in human DD arthropathies.

Fatigue properties of hydroxyapatite-coated dental implants after exposure to a periodontal pathogen.

We studied the fatigue properties of rods (4 mm diameter) of hydroxyapatite-coated, titanium alloy implant material after it was exposed to a periodontal pathogen, Actinobacillus actinomycetemcomitans (Aa). We varied the crystallinity of the hydroxyapatite (HA) coating in these rods to the levels of, 60.5%, 52.8%, and 47.8%. Each rod was first inoculated with Aa in the log phase of its growth cycle. After 48 h, we counted the adhered cells. We measured the dissolution of HA coating due to bacterial exposure alone by determining the calcium and phosphate concentrations in the bacterial growth media. Once the adherent bacteria were removed from these rods, we subjected them to 5 million cycles of fatigue testing after immersion in Lactated Ringer's solution. We then determined the calcium and phosphate concentrations in the fatigue media. We found additional coating loss after fatiguing of the samples. This coating loss was a cumulative effect of bacterial exposure and fatigue loading of the hydroxyapatite-coated dental implant alloy. The lower crystallinity sample showed a higher loss of coating within the range of crystallinity studied here. The HA coating in implants during clinical use may undergo such changes, because they are exposed to the same bacteria.