Precision computerised cognitive behavioural therapy (cCBT) for adolescents with depression: a pilot and feasibility randomised controlled trial protocol for SPARX-UK

BACKGROUND

A serious game called SPARX (Smart, Positive, Active, Realistic, X-factor thoughts), originally developed in New Zealand and incorporating cognitive behavioural therapy (CBT) principles, has been shown to help reduce symptoms of depression and anxiety in adolescents with mild to moderate depression in studies undertaken in Australasia. However, SPARX has never been trialled in the United Kingdom (UK), and there have been issues relating to low engagement when it has been used in a real-world context.

AIMS

To conduct the first pilot and feasibility randomised controlled trial (RCT) in England to explore the use of SPARX in different settings. The trial will explore whether SPARX supported by an e-coach (assistant psychologists) improves adherence and engagement compared with self-directed (i.e. self-help) use. The trial results will be used to inform the optimal mode of delivery (SPARX supported vs. SPARX self-directed), to calculate an appropriate sample size for a full RCT, and to decide which setting is most suitable.

METHODS

Following consultation with young people to ensure study suitability/appropriateness, a total of 120 adolescents (11-19 years) will be recruited for this three-arm study. Adolescents recruited for the study across England will be randomised to receive either SPARX with human support (from an e-coach), self-directed SPARX, or a waitlist control group. Assessments will be conducted online at baseline, week 4, and 8-10-week post-randomisation. The assessments will include measures which capture demographic, depression (Patient Health Questionnaire modified for adolescents [PHQ-A]) and anxiety (Revised Child Anxiety and Depression Scale [RCADS]) symptomatology, and health-related quality-of-life data (EQ-5D-Y and proxy version). Analyses will be primarily descriptive. Qualitative interviews will be undertaken with a proportion of the participants and clinical staff as part of a process evaluation, and the qualitative data gathered will be thematically analysed. Finally, feasibility data will be collected on recruitment details, overall study uptake and engagement with SPARX, participant retention, and youth-reported acceptability of the intervention.

DISCUSSION

The findings will inform the design of a future definitive RCT of SPARX in the UK. If the subsequent definitive RCT demonstrates that SPARX is effective, then an online serious game utilising CBT principles ultimately has the potential to improve the provision of care within the UK's health services if delivered en masse.

TRIAL REGISTRATION

ISRCTN: ISRCTN15124804. Registered on 16 January 2023, https://www.isrctn.com/ISRCTN15124804 .

Crystal structures, Hirshfeld analysis, and energy framework analysis of two differently 3'-substituted 4-methylchalcones: 3'-(N=CHC6H4-p-CH3)-4-methylchalcone and 3'-(NHCOCH3)-4-methylchalcone

Two crystal structures of chalcones, or 1,3-diarylprop-2-en-1-ones, are presented; both contain a p-methyl substitution on the 3-Ring, but differ with respect to the m-substitution on the 1-Ring. Their systematic names are (2E)-3-(4-methylphenyl)-1-(3-{[(4-methylphenyl)methylidene]amino}phenyl)prop-2-en-1-one (C₂₄H₂₁NO) and N-{3-[(2E)-3-(4-methylphenyl)prop-2-enoyl]phenyl}acetamide (C₁₈H₁₇NO₂), which are abbreviated as 3'-(N=CHC₆H₄-p-CH₃)-4-methylchalcone and 3'-(NHCOCH₃)-4-methylchalcone, respectively. Both chalcones represent the first reported acetamide-substituted and imino-substituted chalcone crystal structures, adding to the robust library of chalcone structures within the Cambridge Structural Database. The crystal structure of 3'-(N=CHC₆H₄-p-CH₃)-4-methylchalcone exhibits close contacts between the enone O atom and the substituent arene ring, in addition to C...C interactions between the substituent arene rings. The structure of 3'-(NHCOCH₃)-4-methylchalcone exhibits a unique interaction between the enone O atom and the 1-Ring substituent, contributing to its antiparallel crystal packing. In addition, both structures exhibit π-stacking, which occurs between the 1-Ring and R-Ring for 3'-(N=CHC₆H₄-p-CH₃)-4-methylchalcone, and between the 1-Ring and 3-Ring for 3'-(NHCOCH₃)-4-methylchalcone.

True molecular conformation and structure determination by three-dimensional electron diffraction of PAH by-products potentially useful for electronic applications

The true molecular conformation and the crystal structure of benzo[e]dinaphtho[2,3-a;1',2',3',4'-ghi]fluoranthene, 7,14-diphenylnaphtho[1,2,3,4-cde]bisanthene and 7,16-diphenylnaphtho[1,2,3,4-cde]helianthrene were determined ab initio by 3D electron diffraction. All three molecules are remarkable polycyclic aromatic hydrocarbons. The molecular conformation of two of these compounds could not be determined via classical spectroscopic methods due to the large size of the molecule and the occurrence of multiple and reciprocally connected aromatic rings. The molecular structure of the third molecule was previously considered provisional. These compounds were isolated as by-products in the synthesis of similar products and were at the same time nanocrystalline and available only in very limited amounts. 3D electron diffraction data, taken from submicrometric single crystals, allowed for direct ab initio structure solution and the unbiased determination of the internal molecular conformation. Detailed synthetic routes and spectroscopic analyses are also discussed. Based on many-body perturbation theory simulations, benzo[e]dinaphtho[2,3-a;1',2',3',4'-ghi]fluoranthene may be a promising candidate for triplet-triplet annihilation and 7,14-diphenylnaphtho[1,2,3,4-cde]bisanthene may be a promising candidate for intermolecular singlet fission in the solid state.

Structure determination, thermal stability and dissolution rate of δ-indomethacin

The structure solution of the δ-polymorph of indomethacin was obtained using three-dimensional electron diffraction. This form shows a significantly enhanced dissolution rate compared with the more common and better studied α- and γ-polymorphs, indicating better biopharmaceutical properties for medicinal applications. The structure was solved in non-centrosymmetric space group P2₁ and comprises two molecules in the asymmetric unit. Packing and molecule conformation closely resemble indomethacin methyl ester and indomethacin methanol solvate. Knowledge of the structure allowed the rational interpretation of spectroscopic IR and Raman data for δ-polymorph and a tentative interpretation for still unsolved indomethacin polymorphs. Finally, we observed a solid-solid transition from δ-polymorph to α-polymorph that can be driven by similarities in molecular conformation.

3D Electron Diffraction Structure Determination of Terrylene, a Promising Candidate for Intermolecular Singlet Fission

Herein we demonstrate the prowess of the 3D electron diffraction approach by unveiling the structure of terrylene, the third member in the series of peri‐condensed naphthalene analogues, which has eluded structure determination for 65 years. The structure was determined by direct methods using electron diffraction data and corroborated by dispersion‐inclusive density functional theory optimizations. Terrylene crystalizes in the monoclinic space group P2₁/a, arranging in a sandwich‐herringbone packing motif, similar to analogous compounds. Having solved the crystal structure, we use many‐body perturbation theory to evaluate the excited‐state properties of terrylene in the solid‐state. We find that terrylene is a promising candidate for intermolecular singlet fission, comparable to tetracene and rubrene.

Ethnicity/race and service-connected disability disparities in civilian traumatic brain injury mechanism of injury and VHA health services costs in military veterans: Evidence from a Level 1 Trauma Center and VA Medical Center

Introduction

The objective of this study was to examine the association of military veteran socio-demographics and service-connected disability with civilian mechanism of traumatic brain injury and long-term Veterans Health Administration (VHA) costs.

Methods

We conducted a 17-year retrospective longitudinal cohort study of veterans with a civilian-related traumatic brain injury from a Level 1 Trauma Center between 1999 and 2013, with VHA follow-up through 2016. We merged trauma center VHA data, and used logit to model mechanism of injury, and generalized linear model to model VHA costs.

Results

African American race or Hispanic ethnicity veterans had a higher unadjusted rate of civilian assault/gun as mechanism of injury (15.38%) relative to non-Hispanic White (7.19%). African American race or Hispanic veterans who were discharged from the trauma center with traumatic brain injury and followed in VHA had more than twice the odds of assault/gun (OR 2.47; 95% CI 1.16:5.26), after adjusting for sex, age, and military service-connected disability. Veterans with service-connected disability ≥50% had more than twice the odds of assault/gun (OR 2.48; 95% CI 0.97:6.31). Assault/gun was associated with significantly higher annual VHA costs post-discharge ($16,807; 95% CI 672:32,941) among non-Hispanic White veterans. Military service-connected disability ≥50% was associated with higher VHA costs among both non-Hispanic White ($44,987; 95% CI $17,159:$72,816) and African American race or Hispanic ($37,901; 95% CI $4,543:$71,258) veterans.

Conclusions

We found that African American race or Hispanic veterans had higher adjusted likelihood of assault/gun mechanism of traumatic brain injury, and non-Hispanic White veterans had higher adjusted annual VHA resource costs associated with assault/gun, post trauma center discharge. Veterans with higher than 50% service-connected disability had higher likelihood of assault/gun and higher adjusted annual VHA resource costs. Assault/gun prevention efforts may be indicated within the VHA, especially in minority and service-connected disability veterans. More data from Level 1 Trauma Centers are needed to assess the generalizability of these findings.

Structural effects of halogen bonding in iodochalcones

The structures of three iodochalcones, functionalized with fluorine or a nitro group, have been investigated to explore the impact of different molecular electrostatic distributions on the halogen bonding within each crystal structure. The strongly withdrawing nitro group presented a switch of the halogen bond from a lateral to a linear motif. Surprisingly, this appears to be influenced by a net positive shift in charge distribution around the lateral edges of the σ-hole, making the lateral I...I bonding motif less preferable. A channel of amphoteric I...I type II halogen bonds is observed for a chalcone molecule, which was not previously reported in chalcones, alongside an example of the common synthon involving extended linear chains of I...O₂N donor-acceptor halogen bonds. This work shows that halogenated chalcones may be an interesting target for developing halogen bonding as a significant tool within crystal engineering, a thus far underexplored area for this common structural motif.

Development and evaluation of an online education tool on attention deficit hyperactivity disorder for general practitioners: the important contribution of co-production

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is underdiagnosed in the UK and the assessment and diagnosis pathway often involves a general practitioner (GP) referral to secondary care services. GPs' levels of knowledge and understanding about ADHD is often a significant barrier in patients accessing care. The development of an online education resource could improve GPs knowledge of ADHD and optimise appropriate referrals. Involving end-users in co-creating interventions may enhance their clinical utility and impact routine clinical practice. However, there is limited published evidence describing how to meaningfully involve stakeholders in both the design and development components of co-production.

METHOD

We report a step wise, co-production approach towards developing an online ADHD education intervention for GPs. Preparatory work highlighted the relevant topics to be included in the intervention, from which educational videos were then developed. Workshops were then conducted with GPs, leading to further refinement of the video content and subsequently the final intervention. A pilot usability study (n = 10 GPs) was then conducted to assess the intervention's acceptability, feasibility and accessibility.

RESULTS

The development of the online intervention was greatly facilitated by the involvement of GPs. Having a co-production development process ensured the consistent adaptation of the intervention to meet GPs' needs. The usability study showed that the content of the intervention was suitable, easily accessible, engaging and delivered at an acceptable level of intensity, validating the development approach taken.

CONCLUSION

While further studies are needed to evaluate the efficacy of the developed intervention, preliminary findings demonstrated that it was acceptable and well received. The importance of co-development was highlighted in developing an intervention that addresses specific needs for GPs. This development approach may be useful for other researchers and developers of clinical interventions.

Metastable crystalline phase formation in deep eutectic systems revealed by simultaneous synchrotron XRD and DSC

The phase behaviour of various deep eutectic systems was analysed using concurrent synchrotron powder X-ray diffraction and differential scanning calorimetry. Deep eutectic systems containing the pharmaceuticals metacetamol, 2-ethoxybenzamide or benzamide as binary mixtures with phenol revealed new crystalline phases melting either before or with crystals of phenol, highlighting their lower stabilities. Furthermore, in the phenol : 2-ethoxybenzamide system it was shown that multiple metastable phases can form, highlighting the potential for the separation of a hierarchy of crystal structures with differing stabilities from eutectic systems. Through these experiments, we strengthen the idea that eutectic systems can be described by understanding the formation and stabilities of metastable co-crystalline structures. These novel results lead to a deeper understanding of the structure and thermodynamics of deep eutectic solvents, with relevance for analagous systems across materials science.

Crystal structures of three functionalized chalcones: 4'-di-methyl-amino-3-nitro-chalcone, 3-di-methyl-amino-3'-nitrochalcone and 3'-nitro-chalcone

The structure of three functionalized chalcones (1,3-di-aryl-prop-2-en-1-ones), containing combinations of nitro and di-methyl-amino functional groups, are presented, namely, 1-[4-(di-methyl-amino)-phen-yl]-3-(3-nitro-phen-yl)prop-2-en-1-one, C₁₇H₁₆N₂O₃, Gp8m, 3-[3-(di-methyl-amino)-phen-yl]-1-(3-nitro-phen-yl)prop-2-en-1-one, C₁₇H₁₆N₂O₃, Hm7m and 1-(3-nitro-phen-yl)-3-phenyl-prop-2-en-1-one, C₁₅H₁₁NO₃, Hm1-. Each of the mol-ecules contains bonding motifs seen in previously solved crystal structures of functionalized chalcones, adding to the large dataset available for these small organic mol-ecules. The structures of all three of the title compounds contain similar bonding motifs, resulting in two-dimensional planes of mol-ecules formed via C-H⋯O hydrogen-bonding inter-actions involving the nitro- and ketone groups. The structure of Hm1- is very similar to the crystal structure of a previously solved isomer [Jing (2009 ▸). Acta Cryst. E65, o2510].

Crystal structure and Hirshfeld analysis of 3'-bromo-4-methyl-chalcone and 3'-cyano-4-methyl-chalcone

Two crystal structures of chalcones, or 1,3-di-aryl-prop-2-en-1-ones, are presented; both contain a methyl substitution on the 3-Ring, but differ on the 1-Ring, bromo versus cyano. The compounds are 3'-bromo-4-methyl-chalcone [systematic name: 1-(2-bromo-phen-yl)-3-(4-methyl-phen-yl)prop-2-en-1-one], C16H13BrO, and 3'-cyano-4-methyl-chalcone {systematic name: 2-[3-(4-methyl-phen-yl)prop-2-eno-yl]benzo-nitrile}, C17H13NO. Both chalcones meaningfully add to the large dataset of chalcone structures. The crystal structure of 3'-cyano-4-methyl-chalcone exhibits close contacts with the cyano nitro-gen that do not appear in previously reported disubstituted cyano-chalcones, namely inter-actions between the cyano nitro-gen atom and a ring hydrogen atom as well as a methyl hydrogen atom. The structure of 3'-bromo-4-methyl-chalcone exhibits a type I halogen bond, similar to that found in a previously reported structure for 4-bromo-3'-methyl-chalcone.

The solubility and stability of heterocyclic chalcones compared with trans-chalcone

Heterocyclic chalcones are a recently explored subgroup of chalcones that have sparked interest due to their significant antibacterial and antifungal capabilities. Herein, the structure and solubility of two such compounds, (E)-1-(1H-pyrrol-2-yl)-3-(thiophen-2-yl)prop-2-en-1-one and (E)-3-phenyl-1-(1H-pyrrol-2-yl)prop-2-en-1-one, are assessed. Single crystals of (E)-1-(1H-pyrrol-2-yl)-3-(thiophen-2-yl)prop-2-en-1-one were grown, allowing structural comparisons between the heterocyclic chalcones and (2E)-1,3-diphenylprop-2-en-1-one, trivially known as trans-chalcone. The two heterocyclic chalcones were found to be less soluble in all solvents tested and to have higher melting points than trans-chalcone, probably due to their stronger intermolecular interactions arising from the functionalized rings. Interestingly, however, it was found that the addition of the thiophene ring in (E)-1-(1H-pyrrol-2-yl)-3-(thiophen-2-yl)prop-2-en-1-one increased both the melting point and solubility of the sample compared with (E)-3-phenyl-1-(1H-pyrrol-2-yl)prop-2-en-1-one. This observation may be key for the future crystal engineering of heterocyclic chalcones for pharmaceutical applications.

Protocol for the Process Evaluation of the Online Remote Behavioural Intervention for Tics (ORBIT) randomized controlled trial for children and young people

BACKGROUND

Process evaluations are an important component in the interpretation and understanding of outcomes in trials. The Online Remote Behavioural Intervention for Tics (ORBIT) study is a randomized controlled trial evaluating the effectiveness of an Internet-delivered behavioural intervention (called BIP TIC) compared to an Internet-delivered education programme aimed at children and young people with tics. A process evaluation will be undertaken alongside the main trial to determine precisely how the behavioural intervention works and ascertain whether, and if so, how, the intervention could be successfully implemented in standard clinical practice. This protocol paper describes the rationale, aims, and methodology of the ORBIT trial process evaluation.

METHODS

The process evaluation will have a mixed-methods design following the UK Medical Research Council 2015 guidelines, comprising both quantitative and qualitative data collection. This will include analysing data usage of participants in the intervention arm; purposively sampled, semi-structured interviews of parents and children, therapists and supervisors, and referring clinicians of the ORBIT trial, as well as analysis of qualitative comments put into the online therapy platform by participants at the end of treatment. Qualitative data will be analysed thematically. Quantitative and qualitative data will be integrated in a triangulation approach, to provide an understanding of how the intervention works, and what resources are needed for effective implementation, uptake and use in routine clinical care.

DISCUSSION

This process evaluation will explore the experiences of participants, therapists and supervisors and referring clinicians of a complex online intervention. By contextualising trial efficacy results, this will help understand how and if the intervention worked and what may be required to sustain the implementation of the treatment long term. The findings will also aid in our understanding of factors that can affect the success of complex interventions. This will enable future researchers developing online behavioural interventions for children and young people with mental health and neurological disorders to gain invaluable information from this process evaluation.

TRIAL REGISTRATION

International Standard Randomised Controlled Trials Number, ISRCTN70758207. Registered on 20 March 2018. ClinicalTrials.gov, NCT03483493. Registered on 30 March 2018.

Potential applications of nanopore sequencing for forensic analysis

Advancements in DNA sequencing technologies are occurring at a rapid rate. Various platforms have proven useful in all aspects of health and science research, from molecular diagnostics in cancer research to spore identification in bioterrorism. In the field of forensics, one particular single-molecule sequencing platform shows promise for becoming a viable solution for small to midsize forensic laboratories. Oxford Nanopore Technologies (ONT) has developed a portable, nanopore-based sequencing instrument that has already been utilized for on-site identification of Zika and Ebola viruses, full genome sequencing, evaluation of DNA and RNA base modifications, and enrichment-free mitochondrial DNA analysis. The rapid development of this technology creates possibilities relevant to standard DNA sequencing, direct analysis of forensic samples, including blood, semen, and buccal swabs, mitochondrial DNA analysis, SNP and STR analysis, familial identification, and microbial identification for bioterrorism and geolocation. The small size of the platform, its low cost, and its requirement of only basic laboratory equipment makes this platform well suited for small laboratories wishing to begin developing expertise in sequence-based forensic analyses. Herein, we outline recent developments and applications of nanopore sequencing technologies and their potential application in forensic analysis. We address current and potential techniques in mitochondrial DNA analysis, SNP and STR typing, and microbial identification. Additionally, we discuss recent developments in library preparation and data analysis tool further streamlining the sequencing process that integrate workflows in laboratories or in remote field scenarios.

Crystal structure and Hirshfeld surface analysis of (E)-3-(3-iodo-phen-yl)-1-(4-iodo-phen-yl)prop-2-en-1-one

The title compound, C₁₅H₁₀I₂O, is a halogenated chalcone formed from two iodine substituted rings, one para-substituted and the other meta-substituted, linked through a prop-2-en-1-one spacer. The crystal structure shows the mol­ecules contain halogen bonds which are always between equivalent iodine atoms, either para–para or meta–meta.

The title compound, C₁₅H₁₀I₂O, is a halogenated chalcone formed from two iodine substituted rings, one para-substituted and the other meta-substituted, linked through a prop-2-en-1-one spacer. In the mol­ecule, the mean planes of the 3-iodo­phenyl and the 4-iodo­phenyl groups are twisted by 46.51 (15)°. The calculated electrostatic potential surfaces show the presence of σ-holes on both substituted iodines. In the crystal, the mol­ecules are linked through type II halogen bonds, forming a sheet structure parallel to the bc plane. Between the sheets, weak inter­molecular C—H⋯π inter­actions are observed. Hirshfeld surface analysis showed that the most significant contacts in the structure are C⋯H/H⋯C (31.9%), followed by H⋯H (21.4%), I⋯H/H⋯I (18.4%). I⋯I (14.5%) and O⋯H/H⋯O (8.1%).

An experimental and computational study into the crystallisation propensity of 2nd generation sulflower

The crystallisation propensity of the newly synthesised molecule persulfurated coronene has been investigated through a number of experimental methods. Electrostatic potential calculations and multi-molecular optimisations show that face-face interactions are far more favorable than edge-face interactions, severely restricting the ability of the molecule to crystallise.

Integrin α6 and EGFR signaling converge at mechanosensitive calpain 2

Cells sense and respond to mechanical cues from the extracellular matrix (ECM) via integrins. ECM stiffness is known to enhance integrin clustering and response to epidermal growth factor (EGF), but we lack information on when or if these mechanosensitive growth factor receptors and integrins converge intracellularly. Towards closing this knowledge gap, we combined a biomaterial platform with transcriptomics, molecular biology, and functional assays to link integrin-mediated mechanosensing and epidermal growth factor receptor (EGFR) signaling. We found that high integrin α6 expression controlled breast cancer cell adhesion and motility on soft, laminin-coated substrates, and this mimicked the response of cells to EGF stimulation. The mechanisms that drove both mechanosensitive cell adhesion and motility converged on calpain 2, an intracellular protease important for talin cleavage and focal adhesion turnover. EGF stimulation enhanced adhesion and motility on soft substrates, but required integrin α6 and calpain 2 signaling. In sum, we identified a new role for integrin α6 mechanosensing in breast cancer, wherein cell adhesion to laminin on soft substrates mimicked EGF stimulation. We identified calpain 2, downstream of both integrin α6 engagement and EGFR phosphorylation, as a common intracellular signaling node, and implicate integrin α6 and calpain 2 as potential targets to inhibit the migration of cancer cells in stiff tumor environments.

Lamotrigine ethanol monosolvate

Lamotrigine is an active pharmaceutical ingredient used as a treatment for epilepsy and psychiatric disorders. Single crystals of an ethano-late solvate, C9H7Cl2N5·C2H5OH, were produced by slow evaporation of a saturated solution from anhydrous ethanol. Within the crystal structure, the lamotrigine mol-ecules form dimers through N-H⋯N hydrogen bonds involving the amine N atoms in the ortho position of the triazine group. These dimers are linked into a tape motif through hydrogen bonds involving the amine N atoms in the para position. The ethanol and lamotrigine are present in a 1:1 ratio in the lattice with the ethyl group of the ethanol mol-ecule exhibiting disorder with an occupancy ratio of 0.516 (14):0.484 (14).

Acute and delayed protective effects of pharmacologically induced hypothermia in an intracerebral hemorrhage stroke model of mice

Hemorrhagic stroke, including intracerebral hemorrhage (ICH), is a devastating subtype of stroke; yet, effective clinical treatment is very limited. Accumulating evidence has shown that mild to moderate hypothermia is a promising intervention for ischemic stroke and ICH. Current physical cooling methods, however, are less efficient and often impractical for acute ICH patients. The present investigation tested pharmacologically induced hypothermia (PIH) using the second-generation neurotensin receptor (NTR) agonist HPI-201 (formerly known as ABS-201) in an adult mouse model with ICH. Acute or delayed administrations of HPI-201 (2mg/kg bolus injection followed by 2 injections of 1mg/kg, i.p.) were initiated at 1 or 24h after ICH. HPI-201 induced mild hypothermia within 30 min and body and brain temperatures were maintained at 32.7 ± 0.4°C for at least 6h without causing observable shivering. With the 1-h delayed treatment, HPI-201-induced PIH significantly reduced ICH-induced cell death and brain edema compared to saline-treated ICH animals. When HPI-201-induced hypothermia was initiated 24h after the onset of ICH, it still significantly attenuated brain edema, cell death and blood-brain barrier breakdown. HPI-201 significantly decreased the expression of matrix metallopeptidase-9 (MMP-9), reduced caspase-3 activation, and increased Bcl-2 expression in the ICH brain. Moreover, ICH mice received 1-h delayed HPI-201 treatment performed significantly better in the neurological behavior test 48 h after ICH. All together, these data suggest that systemic injection of HPI-201 is an effective hypothermic strategy that protects the brain from ICH injury with a wide therapeutic window. The protective effect of this PIH therapy is partially mediated through the alleviation of apoptosis and neurovascular damage. We suggest that pharmacological hypothermia using the newly developed neurotensin analogs is a promising therapeutic treatment for ICH.

Parathyroid hormone-related protein inhibits DKK1 expression through c-Jun-mediated inhibition of β-catenin activation of the DKK1 promoter in prostate cancer

Prostate cancer (PCa)bone metastases are unique in that majority of them induce excessive mineralized bone matrix, through undefined mechanisms, as opposed to most other cancers that induce bone resorption. Parathyroid hormone-related protein (PTHrP) is produced by PCa cells and intermittent PTHrP exposure has bone anabolic effects, suggesting that PTHrP could contribute to the excess bone mineralization. Wnts are bone-productive factors produced by PCa cells, and the Wnt inhibitor Dickkopfs-1 (DKK1) has been shown to promote PCa progression. These findings, in conjunction with the observation that PTHrP expression increases and DKK1 expression decreases as PCa progresses, led to the hypothesis that PTHrP could be a negative regulator of DKK1 expression in PCa cells and, hence, allow the osteoblastic activity of Wnts to be realized. To test this, we first demonstrated that PTHrP downregulated DKK1 mRNA and protein expression. We then found through multiple mutated DKK1 promoter assays that PTHrP, through c-Jun activation, downregulated the DKK1 promoter through a transcription factor (TCF) response element site. Furthermore, chromatin immunoprecipitation (ChIP) and re-ChIP assays revealed that PTHrP mediated this effect through inducing c-Jun to bind to a transcriptional activator complex consisting of β-catenin, which binds the most proximal DKK1 promoter, the TCF response element. Together, these results demonstrate a novel signaling linkage between PTHrP and Wnt signaling pathways that results in downregulation of a Wnt inhibitor allowing for Wnt activity that could contribute the osteoblastic nature of PCa.

ADAM-mediated amphiregulin shedding and EGFR transactivation

INTRODUCTION

The ectodomain shedding of epidermal growth factor receptor (EGFR) ligands, such as amphiregulin (AREG), by ADAMs (A Disintegrin And Metalloproteases) can be stimulated by G protein-coupled receptor (GPCR) agonists. Interactions between the CXCR4 GPCR and the CXCL12 chemokine have been shown to mediate gene transcription and cellular proliferation in non-transformed and transformed prostate epithelial cells, as well as motility/invasiveness in transformed cells.

OBJECTIVES

In this report, we investigated the ability of CXCL12 to stimulate amphiregulin ectodomain shedding in non-transformed and transformed prostate epithelial cells that respond proliferatively to sub-nanomolar levels of CXCL12 and amphiregulin.

MATERIALS AND METHODS

Non-transformed N15C6 and transformed PC3 prostate epithelial cells were assessed for amphiregulin shedding, ADAM activation, Src phosphorylation and EGFR activation using ELISA, immunoblot, and immunoprecipitation techniques, and for proliferation using cell counting after stimulation with CXCL12 or vehicle.

RESULTS

The results of these studies identify CXCL12 as a novel inducer of amphiregulin ectodomain shedding and show that both basal and CXCL12-mediated amphiregulin shedding are ADAM10- and Src kinase-dependent in non-transformed N15C6 cells. In contrast, amphiregulin shedding is not amplified subsequent to stimulation with exogenous CXCL12, and is not reduced subsequent to metalloprotease- or Src kinase-inhibition, in highly aggressive PC3 prostate cancer cells. These data also show that CXCL12-mediated cellular proliferation requires EGFR transactivation in a Src- and ADAM-dependent manner in non-transformed prostate epithelial cells. However, these same mechanisms are dysfunctional in highly transformed prostate cancer cells, which secrete amphiregulin in an autocrine manner that cannot be repressed through metalloprotease- or Src kinase inhibition.

CONCLUSION

These findings show that non-transformed and transformed prostate epithelial cells may employ different mechanisms to activate EGFR ligands and thereby utilize the EGFR axis to promote cellular proliferation.

Clinical value of renal biopsy in patients with asymptomatic microscopic hematuria with and without low-grade proteinuria

BACKGROUND

The decision whether to perform renal biopsy on patients with persistent asymptomatic microscopic hematuria (AMH) with and without low-grade proteinuria (LGP) remains controversial as, although often diagnostic, the information gained seldom alters clinical management. Our study investigates the clinical value of renal biopsy in patients with isolated AMH versus those with AMH and LGP.

METHODS

Between 1996 and 2002, we identified 89 patients with AMH and 46 with AMH and LGP. The patients were asymptomatic, free from systemic illness, had a sterile urine, normal serum creatinine, normal renal and bladder ultrasound, less than 2.5 g proteinuria/day, underwent successful renal biopsy and were followed-up for a mean period of 46 +/- 12 months.

RESULTS

In patients with isolated AMH, thin basement membrane nephropathy (TBMN) was diagnosed in 43%, IgA nephropathy in 20%, minor abnormalities in 19% and normal biopsies in 18%. In patients with AMH and LGP, IgA nephropathy was diagnosed in 46%, other major nephropathies in 26%, minor abnormalities in 17%, TBMN in 7% and normal biopsies in 4%. At follow-up, 32% of AMH patients and 38% of AMH with LGP patients had a GFR of less than 90 ml/min and 36% and 56%, respectively were hypertensive.

CONCLUSIONS

The results support the current consensus that routine renal biopsy is not indicated for isolated AMH but suggest that biopsy is indicated for AMH and LGP identifying major and potentially progressive nephropathies in 70% of patients, who should be managed by specialist nephrologists.

Active tissue factor shed from human arterial smooth muscle cells adheres to artificial surfaces

Through a series of in vitro assays, this study outlines a flow-mediated process by which active tissue factor (TF), the prime initiator of coagulation, may be transferred from the plasma membrane of vascular smooth muscle cells (VSMCs) to that of artificial surfaces such as those typically associated with intravascular implants. Studies with quiescent and activated rat VSMCs demonstrated that pathologically high shear stresses (tau(w) = 250 dyn cm(-2)) resulted in the loss of TF activity from the cell surface. Subsequent experiments with human VSMCs showed that VSMCs continuously release active TF into their extracellular medium, presumably in the form of lipid vesicles or microparticles, and that fluid shear stress (tauw = 50 dyncm(-2)) or chemical agonists (A23187) can significantly accelerate this release. Experiments with a wide array of polymeric and metallic materials showed that the TF shed from VSMCs was able to adhere to these surfaces and promote the activation of coagulation factor X (FX) at the material surface. Extracellular TF bound strongly to both uncoated and human plasma coated surfaces under a wide range of hemodynamic shear stresses (0-20 dyncm(-2)). When an extracellular, VSMC-derived TF mixture was perfused over Ti 6-4 surfaces, the adhesion of TF was found to be time-dependent, gradually accumulating on the material surface over time. Thus an important criterion in the design or success of intravascular devices may be related to their ability to interact with TF, shed from cell surfaces. This is especially important as TF may lead to thrombotic complications, the products of which may also increase cellular proliferation.

Fibroblasts require protein kinase C activation to respond to hyaluronan with increased locomotion

Hyaluronan (HA) stimulates the motility of some but not all cell types. Here, we show that HA-promoted random motility of ras-transformed 10T1/2 (C3) fibroblasts requires activation of protein kinase C and is associated with rapid uptake of HA in a CD44 and RHAMM-dependent manner. The addition of HA to parental 10T1/2 fibroblasts (parental cells) does not stimulate random motility, but these cells can be 'primed' to respond to HA by treatment with the phorbol ester, PMA, for 4-6 h. This effect of PMA requires protein synthesis, PKC activity and is associated with enhanced uptake of HA. These results suggest that the ability of cells to respond to HA is regulated by a protein kinase C-dependent process that may promote uptake of HA.

Tissue factor pathway inhibitor binds to platelet thrombospondin-1

Tissue factor pathway inhibitor (TFPI) is a Kunitz-type serine proteinase inhibitor that down-regulates tissue factor-initiated blood coagulation. The most biologically active pool of TFPI is associated with the vascular endothelium, however, the biochemical mechanisms responsible for its cellular binding are not entirely defined. Proposed cellular binding sites for TFPI include nonspecific association with cell surface glycosaminoglycans and binding to glycosyl phosphatidylinositol-anchored proteins. Here, we report that TFPI binds specifically and saturably to thrombospondin-1 (TSP-1) purified from platelet alpha-granules with an apparent K(D) of approximately 7.5 nm. Binding is inhibited by polyclonal antibodies against TFPI and partially inhibited by the B-7 monoclonal anti-TSP-1 antibody. TFPI bound to immobilized TSP-1 remains an active proteinase inhibitor. Additionally, in solution phase assays measuring TFPI inhibition of factor VIIa/tissue factor catalytic activity, the rate of factor Xa generation was decreased 55% in the presence of TSP-1 compared with TFPI alone. Binding experiments done in the presence of heparin and with altered forms of TFPI suggest that the basic C-terminal region of TFPI is required for TSP-1 binding. The data provide a mechanism for the recruitment and localization of TFPI to extravascular surfaces within a bleeding wound, where it can efficiently down-regulate the procoagulant activity of tissue factor and allow subsequent aspects of platelet-mediated healing to proceed.

Protein oxidation and enzyme susceptibility in white and gray matter with in vitro oxidative stress: relevance to brain injury from intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating stroke sub-type with high mortality and morbidity. ICH frequently occurs in subcortical white matter generating hematomas that contain high heme iron levels. In this study, we examined the consequences of iron-induced oxidation (1-100 microM Fe2+ for 30 min. or 50 microM Fe2+ for 1-120 min.) on the activities of two oxidatively sensitive enzymes, creatine kinase (CK) and glutamine synthetase (GS), and on an oxidative stress marker, protein carbonyl formation, in porcine cerebral cortical white and gray matter. In vitro iron oxidation produced time and concentration dependent decreases in both CK [maximum decreases of 49.3+/-1.2% and 44.3+/-4.1% (average +/- SEM, N=3) for white and gray matter, respectively] and GS activities (maximum decreases of 16.9+/-1.7% and 13.2+/-1.0% for white and gray matter, respectively) and increases in protein carbonyl formation. Interestingly, protein carbonyl concentrations were significantly greater (p<0.05) in white vs. gray matter at 100 microM iron (30 min.) and 50 microM iron (120 min.). Additionally, CK and GS activities were lower for white versus gray matter at several time points and iron concentrations. It is our hypothesis that iron induced oxidative stress contributes to the pathogenesis of perihematomal brain injury following ICH.

Vascular cell attachment and procoagulant activity on metal alloys

The attachment and growth of vascular smooth muscle cells on biomaterials used as components of devices implanted in the vascular space may influence the biocompatibility of such materials. The nature of the materials may affect the attachment and/or the activation of these cells' procoagulant responses. Therefore, the main objective of this study was to measure the strength of adhesion of these vascular cells to potential biomaterials (titanium, zirconium alloys, and stainless steel) by exposing them to a range of shear stresses (50-300 dyn cm(-2)) in a parallel plate flow chamber. The procoagulant responses of the cells were evaluated by measuring the tissue factor (TF) activity promoted by the different materials under flow conditions. The materials supported distinctly different levels of initial cell adhesion in static culture. However, the fraction of adherent cells did not decline significantly with incrementally increasing shear stress within the range tested. TF expression, as measured by factor Xa (FXa) production. was material-dependent. For example, cells cultured on Ti1313 exhibited more FXa production (13.2 nM 10(-5) cells) than Ti1313(DH) (8.5 nM 10(-5) cells) or stainless steel (2 nM 10(-5) cells). Thus, our studies indicate that the level of adhesion, strength of attachment and the expression of procoagulant activity of adherent vascular cells depend strongly on the nature of the underlying biomaterial.

Mechanical factors affecting hemostasis and thrombosis

Both physical and chemical factors can influence the activity of platelets and coagulation factors responsible for the formation of thrombotic and hemostatic masses in the vicinity of an injured vessel wall. Studies performed in controlled shear devices (viscometers) have indicated that physical factors alone can induce platelet aggregation, even in the absence of exogenous chemical factors. The physical considerations which appear to be important for the local activation of hemostatic/thrombotic mechanisms appear to be related to the magnitude of the shear rate/stress, the duration of the applied physical force and the local geometry. Blood flow alone has multiple influences on platelet and coagulative mechanisms. It has been well established that at physiologically encountered shear conditions, increases in the local shear rate enhance the attachment of platelets to the vessel wall and the growth of platelet aggregates on adherent platelets. In contrast, increases in local shear conditions inhibit the production of fibrin formation on surfaces where tissue factor (TF) is exposed. At levels of shear rate/stress high as compared to normal physiological conditions, but comparable to those observed at the apex of severely stenosed vessels, platelet aggregate formation is dependent on the duration of the exposure time. Considerable advances in our understanding of flow-related mechanisms have evolved from the use of well-defined perfusion chambers employing parallel flow streamlines. However, processes leading to hemostasis and thrombosis generally occur in more complicated flow situations where flow streamlines are not parallel and in which abnormally high, as well as abnormally low, shear rates and shear stress levels may be encountered in close proximity to each other.

Factor Xa generation at the surface of cultured rat vascular smooth muscle cells in an in vitro flow system

The purpose of the present investigation was to explore the effects of well-defined flow conditions on the activity of tissue factor (TF) expressed on the surface of cultured rat vascular smooth muscle cells. Cells were cultured to confluence on Permanox brand slides and stimulated to express TF by a 90 min incubation with fresh growth medium containing 10 percent calf serum. The stimulated cells were then placed in a parallel plate flow chamber and perfused with Hank's Balanced Salt Solution containing factor VIIa, factor X (FX), and calcium. The chamber effluent was collected and assayed for factor Xa (FXa) and the steady-state flux of FXa was calculated. The flux values were 68.73, 94.81, 139.75, 138.19, 316.82, and 592.92 fmole/min/cm2 at wall shear rates of 10, 20, 40, 80, 320, and 1280 s-1, respectively. The FXa flux depended on the wall shear rate to a greater degree than predicted by classical mass transport theory. The flux at each shear rate was three to five times less than that calculated according to the Leveque solution. These features of the experimental data imply nonclassical behavior, which may partially result from a direct effect of flow on the cell layer.

A computational analysis of FXa generation by TF:FVIIa on the surface of rat vascular smooth muscle cells

A computational model was developed to investigate the contribution of classical mass transport and flow parameters to factor X (FX) activation by the tissue factor-factor VIIa complex (TF:VIIa) on one wall of a parallel-plate flow chamber. The computational results were compared to previously obtained experimental data for the generation of factor Xa (FXa) by TF:VIIa on the surface of cultured rat vascular smooth muscle cells. In this study, the complete steady-state convection-diffusion equation was solved using the commercial software package, FLUENT (Fluent Inc., Lebanon, New Hampshire). A user-defined subroutine interfaced with FLUENT implemented the surface reaction which was modeled using classical Michaelis-Menten reaction kinetics. The numerical solutions were obtained for 12 cases which used combinations of three wall shear rates and four reaction rates. The numerically obtained fluxes for a given reaction rate displayed a wall shear rate dependence which ranged from classical kinetic reaction control (no dependence) to pure diffusional control (maximum dependence). The experimental data, however, were not represented by numerical data generated using a single reaction rate. The three numerically obtained fluxes which corresponded most closely to the experimental fluxes were determined using three different Vmax values. This finding supports the hypothesis that there may be a direct effect of flow on the TF:VIIa complex or the cell membrane.

pp60(c-src) is required for cell locomotion regulated by the hyaluronanreceptor RHAMM

The tyrosine kinase pp60(c-src) has been implicated as a regulator of focal adhesion formation and cell spreading. Here we show that c-src also regulates cell motility and is a key component in the signaling pathway triggered by the motogenic hyaluronan receptor RHAMM, which has been shown to regulate focal adhesion turnover and to regulate ras. Fibroblasts derived from mice lacking src, (src (-/-)), have a random locomotion rate that is significantly slower than the corresponding wild-type fibroblasts. Cell locomotion in these mutant cells is restored by the expression of c-src containing a functional kinase domain, but not by the expression of a kinase-deficient src or by a truncated src containing only functional SH2 and SH3 domains. RHAMM is also required for the restoration of src (-/-) cell locomotion. Thus, the motility of cells expressing c-src is reduced to src (-/-) levels by anti-RHAMM blocking antibodies while the cell locomotion of src (-/-) fibroblasts remains unaffected by anti-RHAMM antibodies. We predict that src acts downstream of RHAMM in the regulation of motility, since the expression of a dominant negative src significantly inhibits RHAMM-dependent ras and serum regulated cell locomotion, the expression of v-src enhances cell motility in a RHAMM independent fashion, and there is a physical and functional assocation between src and RHAMM in ras-transformed cells. However, we suggest that RHAMM regulates focal adhesion turnover via additional src-independent mechanisms. Thus, v-src is unable to turnover focal adhesions in the absence of RHAMM. These results directly demonstrate for the first time a role for src in the regulation of cell locomotion and confirm a key and complex role for src in the regulation of the actin cycle.

Assessment of in vivo attachment/phagocytosis by alveolar macrophages

Alveolar macrophages (AMs) are recognized as an important first line of cellular host defense within the lung. Although mechanisms underlying AM response to microorganisms or particulates are well characterized in vitro, experimental approaches to the study of AMs in vivo are limited. To circumvent these limitations, a new assay was developed using fluorescently labelled liposomes or Pneumocystis carinii (PC) organisms which were administered intratracheally into mechanically ventilated rats. After 30 min, the lungs were lavaged and the percentage of administered liposomes or PC bound to AMs was determined by quantifying fluorescence. Factors known to enhance attachment/phagocytosis by AMs in vitro were assayed to determine their effect in vivo. For example, vitronectin (VN)-coated liposomes increased attachment from 25.2 +/- 2.4% to 47.2 +/- 3.0% (p < 0.001), while addition of VN increased the binding of PC to AMs from 16.5 +/- 1.7% to 24.5 +/- 2.2% (p < 0.05). Confocal laser microscopy of cells obtained by lavage provided morphologic evidence of attachment/phagocytosis by AMs. This model will permit the quantitative assessment of the interaction of fluorescently labelled liposomes or microorganisms with AMs in the lower respiratory tract of living animals.

HA receptors: regulators of signalling to the cytoskeleton

Hyaluronan (HA) is a ubiquitous component of the extracellular matrix (ECM) and occurs transiently in both the cell nucleus and cytoplasm. It has been shown to promote cell motility, adhesion, and proliferation and thus it has an important role in such processes as morphogenesis, wound repair, inflammation, and metastasis. These processes require massive cell movement and tissue reorganization and are always accompanied by elevated levels of HA. Many of the effects of HA are mediated through cell surface receptors, three of which have been molecularly characterized, namely CD44, RHAMM, and ICAM-1. Binding of the HA ligand to its receptors triggers signal transduction events which, in concert with other ECM and cytoskeletal components, can direct cell trafficking during physiological and pathological events. The HA mediated signals are transmitted, at least in part, by the activation of protein phosphorylation cascades, cytokine release, and the stimulation of cell cycle proteins. A variety of extracellular signals regulate the expression of both HA and the receptors necessitating that HA-receptor signalling is a tightly controlled process. Regulated production of soluble forms of the receptors, alternately spliced cell surface isoforms, and glycosylation variants of these receptors can dramatically modulate HA binding, ligand specificity, and stimulation of the signalling pathway. When these processes are deregulated cell behaviour becomes uncontrolled leading to developmental abnormalities, abnormal physiological responses, and tumorigenesis. The elucidation of the molecular mechanisms regulating HA-mediated events will not only contribute greatly to our understanding of a variety of disease processes but will also offer many new avenues of therapeutic intervention.

Hyaluronan: RHAMM mediated cell locomotion and signaling in tumorigenesis

Extracellular matrix molecules and their receptors are important regulators of cell movement, adhesion and cytoskeletal organization. Adhesion molecules can also serve to mediate signal transduction and can influence, and sometimes direct, the events required for tumorigenesis. The extracellular matrix molecule, hyaluronan and its receptors have been implicated in transformation and metastasis, in particular the processes of tumor cell motility and invasion. RHAMM (receptor for hyaluronan mediated motility) is required for the cell locomotion of ras-transformed fibrosarcoma cells, cytokine stimulated fibrobasts and T lymphocytes, malignant B cells, and breast carcinoma cells. HA:RHAMM interactions promote cell locomotion via a protein tyrosine kinase signal transduction pathway that targets focal adhesions. The tyrosine kinase pp60c-src is associated with RHAMM in cells and is required for RHAMM mediated cell motility. It is possible that a RHAMM/src pathway induces focal adhesions to signal the cytoskeletal changes required for elevated cell motility seen in tumor progression, invasion and metastasis.

Clinical features and outcome of patients with thin and ultrathin glomerular membranes

There is considerable disagreement regarding the natural history of renal disease associated with thin glomerular basement membranes (TGBM). We followed 43 patients (19 male), mean age 41.6 years (range 19-73) for a mean of 88 months (48-140). TGBM was recognized in adults when glomerular basement membrane thickness, measured from multiple sites in electronmicrographs of renal biopsy tissue as the harmonic mean, was < 320 nm. At presentation, 95% had microscopic haematuria, 12% macroscopic haematuria, 14% loin pain, 28% proteinuria, and 14% hypertension. There was no difference in GBM width between the sexes (male 258 nm vs. female 251 nm) but there was a significant negative correlation between age and GBM width (r = -0.53, p < 0.001), with older patients having the thinnest membranes. Twenty six patients had ultrathin GBM (< 270 nm), of whom 54% had 3+ haematuria vs. 12% of the group with BM > 270 nm (p < 0.01). In the ultrathin group, 71% had loss of anionic charge from the GBM, vs. 17% in those with membranes which were thin but > 270 nm (p < 0.05). Proteinuria occurred more frequently in those with GBM > 270 nm, 65% vs. 8% in the ultrathin group (p < 0.01). Thin GBM were associated with a benign prognosis, as after a mean follow-up of 85 months (48-140), there was no significant change in either serum creatinine or mean arterial blood pressure. Patients with ultrathin GBM had greater loss of GBM anionic charge, which might result in both an alteration of flow characteristics within the glomerular capillaries and also increased fragility of the glomerular basement membrane with likelihood of rupture and resultant macroscopic haematuria.

Characterization of the murine gene encoding the hyaluronan receptor RHAMM

We describe the isolation and characterization of the murine gene encoding RHAMM, a hyaluronan receptor which regulates focal adhesion turnover, is required for cell locomotion and is a critical downstream regulator of ras transformation. The RHAMM gene spans at least 20 kb and comprises 14 exons ranging in size from 75 to 1099 bp. Primer extension studies indicate that the major transcription start point is in position -31, relative to the start Met. Northern blot analysis of mouse fibroblast RNA identified two hybridizing species of 4.2 and 1.7 kb. Comparison of cDNA clones and RT-PCR products with the genomic clones identified alternately spliced exons in both the coding and 5' noncoding regions of RHAMM. In the coding region exon 4 is alternately spliced. The major RHAMM transcript (RHAMM1) in 3T3 fibroblasts does not contain exon 4 and encodes a protein of 70 kDa. A minor transcript containing exon 4, namely RHAMM v4, encodes a 73-kDa protein, as demonstrated by isoform-specific antibodies. Western analysis demonstrated both a major 70-kDa (RHAMM 1) and minor 73-kDa RHAMM protein (v4) in 3T3 murine fibroblast cell lysates. The functional significance of these two isoforms is currently being investigated.

Overexpression of the hyaluronan receptor RHAMM is transforming and is also required for H-ras transformation

Overexpression of the RHAMM gene by transfection into fibroblasts is transforming and causes spontaneous metastases in the lung. H-ras-transformed fibrosarcomas transfected with a dominant suppressor mutant of RHAMM exhibit a so-called revertant phenotype and are completely nontumorigenic and nonmetastatic. Conversely, fibroblasts stably expressing low levels of RHAMM as a result of antisense transfection are resistant to ras transformation. Collectively, these results indicate that RHAMM acts downstream of ras. The loss of functional RHAMM ablates signaling within focal adhesions, in particular changes in focal adhesion kinase phosphorylation, and as a result these focal adhesions are unable to turn over in response to hyaluronan. These results provide evidence of the oncogenic potential of a novel extracellular matrix receptor and establish a functional link between transformation by ras and signaling within focal adhesions that are required for transformation by this oncogene.

Identification of a novel heparin binding domain in RHAMM and evidence that it modifies HA mediated locomotion of ras-transformed cells

We have previously reported that the hyaluronan (HA) receptor RHAMM (Receptor for HA Mediated Motility) [Turley et al., 1991] contains two HA binding motifs located within a 35 amino acid region of its C-terminus end [Yang et al., 1993] and that HA stimulation of the motility of ras-transformed fibroblasts is mediated via its interaction with RHAMM. Here we show that RHAMM also contains binding sites for heparin (HP) and that interaction of HP with these sites can regulate the locomotion of ras-transformed fibroblasts. At low concentrations (0.01 mg/ml), HP inhibited HA-induced locomotion of ras-transformed cells in a manner independent of RHAMM. At higher, but still physiological concentrations (0.1 mg/ml), HP alone stimulated cell locomotion and this stimulation appeared to be RHAMM-dependent as it was blocked by anti-RHAMM antibodies. Other related glycosaminoglycans such as chondroitin sulfate and dermatin sulfate had no effect on cell motility. In ligand blotting assays, GST-RHAMM fusion protein was shown to bind biotin-labelled HP and this binding was displaceable with unlabelled HP. In similar ligand binding analyses conducted with truncations of RHAMM fusion protein, the HP binding region was found to be localized in the same 35 amino acid segment of RHAMM that contains the two HA binding domains. Synthetic peptides corresponding to these HA binding domains were retained on and bound effectively to an HP-Sepharose affinity column. Fusion proteins generated by linkage of these peptides to the non-HP binding amino terminus of RHAMM conferred HP binding capacity to the genetically engineered proteins. Conversely, deletion of the HA binding domains of RHAMM resulted in fusion proteins devoid of HP binding activity. The relative affinities of RHAMM for HA and HP, as determined by competition and transblot assays as well as quantification of binding at various salt concentrations, indicated that RHAMM had lower affinity for HP than that for HA. These results demonstrate the existence of a new HP binding motif that has biological relevance to cell locomotion.

Hyaluronan and the hyaluronan receptor RHAMM promote focal adhesion turnover and transient tyrosine kinase activity

The molecular mechanisms whereby hyaluronan (HA) stimulates cell motility was investigated in a C-H-ras transformed 10T 1/2 fibroblast cell line (C3). A significant (p < 0.001) stimulation of C3 cell motility with HA (10 ng/ml) was accompanied by an increase in protein tyrosine phosphorylation as detected by anti-phosphotyrosine antibodies using immunoblot analysis and immunofluorescence staining of cells. Tyrosine phosphorylation of several proteins was found to be both rapid and transient with phosphorylation occurring within 1 min of HA addition and dissipating below control levels 10-15 min later. These responses were also elicited by an antibody generated against a peptide sequence within the HA receptor RHAMM. Treatment of cells with tyrosine kinase inhibitors (genistein, 10 micrograms/ml or herbimycin A, 0.5 micrograms/ml) or microinjection of anti-phosphotyrosine antibodies inhibited the transient protein tyrosine phosphorylation in response to HA as well as prevented HA stimulation of cell motility. To determine a link between HA-stimulated tyrosine phosphorylation and the resulting cell locomotion, cytoskeletal reorganization was examined in C3 cells plated on fibronectin and treated with HA or anti-RHAMM antibody. These agents caused a rapid assembly and disassembly of focal adhesions as revealed by immunofluorescent localization of vinculin. The time course with which HA and antibody induced focal adhesion turnover exactly paralleled the induction of transient protein tyrosine phosphorylation. In addition, phosphotyrosine staining colocalized with vinculin within structures in the lamellapodia of these cells. Notably, the focal adhesion kinase, pp125FAK, was rapidly phosphorylated and dephosphorylated after HA stimulation. These results suggest that HA stimulates locomotion via a rapid and transient protein tyrosine kinase signaling event mediated by RHAMM. They also provide a possible molecular basis for focal adhesion turnover, a process that is critical for cell locomotion.

Do mesangial immune complex deposits affect the renal prognosis in membranous glomerulonephritis?

Patients with rheumatoid arthritis who develop membranous glomerulonephritis associated with gold or penicillamine therapy have been shown to get better when the drugs are discontinued, whereas up to 50% of patients with idiopathic membranous glomerulonephritis develop renal failure. A feature of the lesion in rheumatoid disease is the presence of mesangial immune complex deposits in addition to the basement membrane deposits of classical idiopathic membranous glomerulonephritis. To determine whether the presence of mesangial immune complexes indicates a different renal outcome in membranous glomerulonephritis we studied 3 groups: group A 10 patients with rheumatoid arthritis and drug induced membranous glomerulonephritis with mesangial immune complex deposits, group B 14 patients with idiopathic membranous glomerulonephritis with additional mesangial immune complex deposits and group C 25 patients having classic idiopathic membranous glomerulonephritis with deposits solely in the glomerular basement membrane. After median follow up of 72 months, nephrotic range proteinuria resolved in all cases in group A after drug withdrawal, 93% of group B, but only 60% of group C (groups A + B vs C, X2 = 7.8, p < 0.01). Serum creatinine remains less than 500 mumol/l in all patients in group A, 93% of group B, but only 64% of group C (groups A + B vs C, X2 = 7.6, p < 0.01). Mesangial immune complex deposits were predominantly of the IgM isotype in both the rheumatoid and idiopathic membranous group. The presence of mesangial immune complex deposits suggests either a different pathogenesis or host responsiveness to that found in classic idiopathic membranous glomerulonephritis, and predicts a more favourable renal outcome.

Idiopathic polymyositis complicated by arthritis and mesangial proliferative glomerulonephritis: case report and review of the literature

A 56-yr-old male developed a systemic illness while receiving cyclical oral etidronate therapy for idiopathic osteoporosis. The illness, characterized by fever, proximal myopathy and inflammatory synovitis, was associated with interstitial lung disease and mesangial proliferative glomerulonephritis. Elevated plasma creatine phosphokinase level and inflammatory muscle biopsy findings confirmed a diagnosis of polymyositis (PM). Antibodies to Jo-1 were also detected. A review of the literature reveals that mesangial proliferation is the commonest glomerular lesion and suggests a possible association between arthritis and glomerulonephritis in PM. The prognosis of this renal lesion appears to be good, although only limited data is available.

A nuclear magnetic resonance study of the glucose metabolism of Hymenolepis diminuta exposed to histamine and serotonin in vitro

The direct effects of the inflammatory mediators, histamine (HI) and serotonin (SE), on the glucose metabolism of Hymenolepis diminuta in vitro were studied by analyzing the excretory products from culture media, containing D-1-13C-glucose and various concentrations of HI and/or SE, by 1H-nuclear magnetic resonance (n.m.r.) spectroscopy. The results revealed that HI markedly accelerated the glycolysis process by increasing the amount of lactate production. The increased glycolytic activity was reflected in a concentration-dependent increase in glucose uptake. Excretion of acetate was also stimulated by HI. A low concentration of SE significantly increased succinate, acetate and lactate excretions, whereas a high concentration had little effect on lactate production and significantly decreased succinate and acetate excretions. A combination of HI and SE treatment at a low concentration had no significant effect, but at a high concentration showed an additive effect, with an increase in lactate production, a decrease in succinate production and an increase in glucose uptake. Thus this work confirms that HI and SE directly influence, albeit differently, energy metabolism of the tapeworm H. diminuta.