Enhancing Food Literacy and Food Security through School Gardening in Rural and Regional Communities

A qualitative case study approach with in-depth, semi-structured interviews of key school staff, and student feedback was used to assess a school kitchen and garden program in the regional area of North-West Tasmania, Australia. A detailed program description was produced to conduct a realist evaluation with a Context-Mechanism-Outcome configuration, followed by a program theory evaluation through the construction of a retrospective program logic model. Dedicated kitchen and garden spaces, knowledgeable teachers committed to the program, provision of sufficient materials and consumables, and support from the school and community were found to be the basic requirements to establish a program. Additionally, it is essential to integrate both the kitchen and garden teaching components into the school curriculum. The positive outcomes (e.g., engagement, participation, knowledge, skills, behavioral change) of the program were dependent on the underlying factors, including dedicated support of school leadership, teaching staff, and the parent body for effective student engagement in the teaching spaces and for wider engagement from families and the community. The students' feedback provided supporting evidence of increased food literacy with improvements in their understanding, abilities, and attitudes towards gardening, producing healthy food, and preparing food. This may further lead to enhanced food security for students' families and the broader community.

POS0478 TOPICAL CALCIUM CHELATORS FOR TARGETING CUTANEOUS CALCIFICATION: PRECLINICAL EVIDENCE OF EFFICACY

Background

Cutis calcinosis, defined as sub-epidermal deposition of calcium salts, is a painful, disabling, disfiguring, problem in 20-40% of patients with systemic sclerosis. Its pathogenesis remains poorly understood and currently there is no effective disease-modifying pharmacotherapy. One potential strategy is topical application of calcium chelating agents, able to penetrate the epidermal barrier and dissolve subcutaneous calcinotic deposits in situ. To date, the only compound reported for this application has been sodium thiosulfate (STS), with often-contradictory results.

Objectives

To test the hypothesis, in pre-clinical studies, that polycarboxylic acids can induce calcium dissolution without skin toxicity, with the long-term aim of developing an effective topical treatment for cutis calcinosis.

Methods

We compared the metal ion-chelating agents citric acid (CA) and ethylenediaminetetraacetic acid (EDTA) - polycarboxylic acids with well-characterised chelation profiles – to STS for their ability to chelate calcium, without inducing cytotoxicity or inflammation (pro-inflammatory cytokine expression and release), using in vitro 2D (keratinocyte [HaCaT]; fibroblast ([HCA2]) and recombinant human epidermal (RHE) models. The resultant data was subsequently used to predict therapeutic concentrations for assessment in a validated skin irritation model (SkinEthicTM; Episkin SA) and to assay maximal percutaneous absorption. At relative dermal concentrations, the dissolution performance of each chelator was further assessed using two different models of calcinosis: 1) pharmaceutical dissolution of a hydroxyapatite (HAp) tablet (1) and; 2) dissolution of a calcified extracellular matrix laid down by mineralising SaOS2 in vitro monolayer culture (2).

Results

Incubation with CA, EDTA and STS induced cytotoxicity in both in vitro cell lines studied at concentrations of >10 mM; only EDTA (10 mM) resulted in inflammatory cytokine release (IL8) from cells at these higher concentrations (cf positive control, Lipopolysaccharide 10 mg/mL). When applied topically to RHE models as near-saturated solutions, none of the chelators were categorised as skin irritants. Due to differences in their relative aqueous solubility, higher concentrations of CA (1600 mM) and STS (1200 mM) could be delivered through the RHE model than EDTA (200 mM). Using a simple linear regression model, the rate of compound absorption was: CA, 0.43 ± 0.05; STS, 0.26 ± 0.03 and; EDTA, 0.05 ± 0.01 g/L/hr. At each time-point, the cumulative concentration of compound in the receptor media was CA > STS > EDTA. Incubation with chelators had no effect on the integrity of the RHE by standard histology. Based on the rate of percutaneous absorption, the dissolution performance of each chelator was tested at relative dermal concentrations for phosphate dissolution (nmoles) of HAp (CA, 9.61 ±0.97; EDTA, 5.38 ± 0.28; 3.78 ± 0.58) and in the calcified in vitro model (Figure 1; CA, 3285 ± 105, STS, 947 ± 95, EDTA, 1174 ± 89), showing the superiority of CA in both model systems.

Figure 1.

Dissolution of a calcified extracellular matrix by citric acid

Conclusion

Overall, this study highlights the promise of polycarboxylic acids, particularly CA, to target subcutaneous calcification, which are neither toxic nor inflammatory to the skin. Specifically, we have identified CA as a potentially more efficacious alternative to STS for the topical treatment of cutis calcinosis.

References

[1]Fei F, Gallas A, Chang YC, Rao Y, Hunter AC, Winpenny REP, Herrick AL, Lockyer NP, Blanford CF. 2017. Quartz crystal microbalance assay of clinical calcinosis samples and their synthetic models differentiates the efficacy of chelation-based treatments. ACS Appl Mater Interfaces, 9(33):27544-27552

[2]Wang QG, Wimpenny I, Dey RE, Zhong X, Youle PJ, Downes S, Watts DC, Budd PM, Hoyland JA, Gough JE. 2018. The unique calcium chelation property of poly(vinyl phosphonic acid-co-acrylic acid) and effects on osteogenesis in vitro. J Biomed Mater Res Part A 2018:106A:168–179

Disclosure of Interests

Kyle Burgess: None declared, Richard Winpenny: None declared, Alberto Saiani: None declared, Ariane Herrick Speakers bureau: Janssen, Consultant of: Arena, Boehringer-Ingelheim, Camurus, CSL-Behring, Gesynta, Grant/research support from: Gesynta, Rachel Watson Consultant of: NAOS, AbbVie, Grant/research support from: Walgreens Alliance Boots.

Parental alienation, coaching and the best interests of the child: Allegations of child sexual abuse in the Family Court of Australia

BACKGROUND

Allegations of child sexual abuse provide complex challenges to family court systems.

OBJECTIVES

Despite being highly criticised in the academic research, this analysis examined whether and how the gendered concepts of parental alienation syndrome or parental alienation more broadly are still being used to rebut allegations of child sexual abuse in family court cases in Australia. Parental Alienation is broadly understood as the deliberate actions of one parent to disrupt and prevent children's ongoing relationships with their other parent, in this case through allegations of abuse.

METHODS

We examined 357 publicly available judgements of the Family Court of Australia between 2010 and 2015. Judgements were analysed qualitatively for key themes using N-VIVO software.

RESULTS

Five themes emerged in the data, including use of the concept of parental alienation, coaching, mothers as manipulative, mothers as mentally ill, and impact of the best interest of the child.

CONCLUSIONS

Results indicate that judgements made in the Family Court of Australia are both similar and divergent from those made in other jurisdictions internationally. The complexity of responding to allegations of child sexual abuse for parents is discussed.

The effect of pitched and vertical ladder ergometer climbing on cardiorespiratory and psychophysical variables

This study aimed to assess whether modifying the pitch of a 75° ladder ergometer to vertical had a cardiorespiratory or psychophysical effect on climbing. Nine male participants climbed a ladder ergometer at 75° and subsequently at 90°, adjusted for an equivalent vertical climb rate, completing three climbing bouts at different vertical speeds. One participant dropped out being unable to complete the climb under the 90° condition. Each was monitored for heart rate (HR), V˙O₂ and rating of perceived exertion (RPE). Results showed vertical climbing induced higher V˙O₂ (mean increase 17.3%), higher HR (mean increase 15.8%), and higher RPE at all speeds and that moving from 75°to vertical exacerbates the effect of speed on the cardiorespiratory response to climbing. This may be explained by increased force production required to maintain balance in a vertical climbing position when the body's centre of mass is not above the feet.

Geographical differences in survival of dogs with non-Hodgkin lymphoma treated with a CHOP based chemotherapy protocol

BACKGROUND

In humans geographical differences in the incidence and presentation of various cancers have been reported. However, much of this information has not been collected in veterinary oncology.

AIM

The purpose of this study was to determine if a geographic difference in progression free survival exists for dogs with lymphoma treated within the US.

MATERIALS AND METHODS

Medical records of 775 cases of canine lymphoma from 3 US regions (west, south and north), treated with CHOP chemotherapy, were retrospectively evaluated. Cases were collected from referral institutions and were required to have received at least one doxorubicin treatment and have follow up information regarding time to progression.

RESULTS

Significant differences in sex (p = 0.05), weight (p = 0.049), stage (p < 0.001), immunophenotype (p = <0.001), and number of doxorubicin doses (p = 0.001) were seen between regions. Upon univariate analysis, progression free survival (PFS) differed by region (p = 0.006), stage (p = 0.009), sub-stage (p = 0.0005), and immunophenotype (p = 0.001). A multivariable Cox regression model showed that dogs in the western region had a significantly shorter PFS when compared to the south and east.

CONCLUSION

PFS was significantly affected by stage, sub-stage and phenotype.

Rapid Chair-Side Test for Detection of Porphyromonas gingivalis

Porphyromonas gingivalis is a keystone pathogen of chronic periodontitis, and its intraoral levels have been shown to predict disease progression (activity). An accurate and sensitive chair-side (point of care) test to determine disease activity is critical for early intervention and clinical management of disease. This study aimed to develop a rapid, chair-side, saliva-based detection of P. gingivalis. Monoclonal antibodies (mAbs) to the A1-adhesin domain of the P. gingivalis RgpA-Kgp proteinase-adhesin complex were screened by enzyme-linked immunosorbent assay and microbial flow cytometry, with 2 mAbs shown to recognize all laboratory and clinical strains tested, without significantly cross-reacting with other oral bacteria tested. With these mAbs, an immunochromatographic device was produced and shown in preclinical studies to detect, in inoculated saliva, all P. gingivalis laboratory strains and clinical isolates tested. The device was able to detect ≥1 × 10⁵ P. gingivalis cells/mL. In a patient age- and sex-matched control clinical cohort, P. gingivalis levels in saliva-as measured by real-time polymerase chain reaction-positively correlated with P. gingivalis levels in subgingival plaque ( r = 0.819, P < 0.01) and clinical parameters of disease ( r = 0.633, P < 0.01). A positive device result strongly correlated with P. gingivalis levels >1 × 10⁵ cells/mL in saliva ( r = 0.778, P < 0.001) and subgingival plaque ( r = 0.715, P < 0.001) with sensitivity, specificity, positive/negative predictive values, and accuracy levels of 95.0%, 93.3%, 90.5%, 96.6%, and 94.0%, respectively. The device result also positively correlated ( r = 0.695, P < 0.01) with disease severity as measured by probing depth. Detection of P. gingivalis in saliva was found to be rapid, taking 3 min from sample collection.

Elastic characterization of platinum/rhodium alloy at high temperature by combined laser heating and laser ultrasonic techniques

We demonstrate an innovative pump-probe technique combined with laser heating to determine the velocity of a surface Rayleigh wave at high temperature. Laser ultrasonics in a point-source-point-receiver configuration was combined with laser heating to evaluate the elastic properties of micron size specimens. The measurements of the velocity of the surface Rayleigh wave (SRW) were conducted at 1070K.

Nano-TiO2/polyurethane composites for antibacterial and self-cleaning coatings

Grafting from polymerization was used to synthesize nano-titania/polyurethane (nTiO(2)/polyurethane) composite coatings, where nTiO(2) was chemically attached to the backbone of the polyurethane polymer matrix with a bifunctional monomer, 2,2-bis(hydroxymethyl) propionic acid (DMPA). This bifunctional monomer can coordinate to nTiO(2) through an available -COOH group, with two available hydroxyl groups that can react with diisocyanate terminated pre-polyurethane through step-growth polymerization. The coordination reaction was monitored by FTIR and TGA, with the coordination reaction found to follow first order kinetics. After step-growth polymerization, the polyurethane nanocomposites were found to be stable on standing with excellent distribution of Ti in the polymer matrix without any significant agglomeration compared to simple physical mixtures of nTiO(2) in the polyurethane coatings. The functionalized nTiO(2)-polyurethane composite coatings showed excellent antibacterial activity against gram-negative bacteria Escherichia coli; 99% of E. coli were killed within less than one hour under solar irradiation. Self-cleaning was also demonstrated using stearic acid as a model for 'dirt'.

Correlations of structure and rates of energy transfer for through-bond energy-transfer cassettes

Fluorescent DNA-labeling cassettes are designed to have a common absorbing chromophore matched to a single exciting laser wavelength, but up to four different emitters. Experiments reported here have examined the energy-transfer rates and fluorescence polarization characteristics for two different types of cassette, involving three distinct relative orientations of the donor and acceptor transition moments and the axis of the rigid linker. Energy-transfer times range from <200 fs to approximately 20 ps, the fastest transfer times occurring when the transition moments of the donor and acceptor species are aligned parallel to the linker axis. Experimental evidence is presented that supports a through-bond energy-transfer mechanism, in contrast with a commercial DNA-labeling agent, which exhibits much slower transfer times controlled by FRET. These rigid cassettes also exhibit polarized fluorescence from the acceptor species, so that this particular type of DNA-labeling probe has some of the advantages of single-molecule probes such as rhodamine and coumarin dyes.

Enantioselective hydrogenations of arylalkenes mediated by [Ir(cod) (JM-Phos) ]+ complexes

Phosphine oxazoline ligands la-j were converted to the corresponding [Ir(cod)(phosphine oxazoline)]+ complexes 2a-j. X-ray diffraction analyses of complexes 2b, 2h, 2i, and 2j were performed. The tert-butyl-, 1,1-diphenylethyl-, and phenyl-oxazoline complexes (2b, 2h, and 2i, respectively) had typical square planar metal environments with chair-like metallocyclic rings. However, the 3,5-di-tert-butylphenyl oxazoline complex 2j was distorted toward a tetrahedral metal geometry. This library of complexes was tested in asymmetric hydrogenations of several arylalkenes. High enantioselectivities and conversions were observed for some substrates. A possible special role for the HPh2C-oxazoline substituent in asymmetric hydrogenations was identified and is discussed. In attempts to rationalize why high enantioselectivities were not observed for some alkenes, a series of deuterium labeling experiments were performed to probe for competing reactions that occurred prior to the hydrogenation step. Double bond migrations were inferred for several substrates, and this is a significant complication in asymmetric hydrogenations of arylalkenes that had not been discussed prior to this study. A mechanistic rationale is proposed involving competing double bond migration for some but not all substrates. Appreciation of this complication will be valuable in further studies aimed at optimization of enantioselection in asymmetric hydrogenations of unfunctionalized alkenes.

Solid-phase syntheses of beta-turn analogues to mimic or disrupt protein-protein interactions

Protein-protein interactions are difficult targets in medicinal chemistry, but they will become increasingly important as data from The Human Genome Project is interpreted. Our work focuses on beta-turn mimics that are designed to mimic or disrupt some of these interactions. Solid-phase syntheses and preferred conformations of beta-turn mimics that incorporate dipeptide units are discussed. The activity of one illustrative compound that potentiates the interaction of the nerve growth factor with its transmembrane tyrosine kinase receptor TrkA is outlined. Finally, the importance of dimeric turn mimics and some new approaches to these are described.

Facile macrocyclizations to beta-turn mimics with diverse structural, physical, and conformational properties

On-resin S(N)Ar reactions were performed to prepare the macrocyclic beta-turn mimics 1a-n (Scheme 1 and Table 1). These reactions occurred more efficiently than completely analogous macrocyclization reactions that do not involve an iodinated aromatic electrophile. The synthesis was also modified to allow introduction of an alkyne via a solid-phase Sonogashira reaction (giving compound 2, Scheme 2) and an aryne via a solid-phase Suzuki reaction (giving compound 3, Scheme 2). Conformational analyses of three illustrative compounds, i.e., 1i, 2, and 3, were performed using a combination of NMR, circular dichroism, and computer-aided molecular simulation methods. Overall, the preferred conformations of all three molecules tended to be type-I-like beta-turns, but for compound 3 interaction of the electron cloud of the aryl substituent with the oxygen lone pairs seems to cause differences in the preferred orientation of the turn frameworks. This study illustrates how iodinated electrophiles can be used in solid-phase S(N)Ar reactions to increase the molecular and conformational diversity in a library.

Dimeric beta-turn peptidomimetics as ligands for the neurotrophin receptor TrkC

Twelve dimeric peptidomimetics 1 were prepared via a divergent-convergent strategy. These peptidomimetics incorporated the same amino acids as i +1 and i + 2 residues in key beta-turns of the neurotrophin NT-3. Cytosensor microphysiometry was used to gauge the effects of the dimers 1 on cells that overexpress the NT-3 receptor, TrkC. Increases in extracellular acidification rates were observed for some monomers 3, but the active dimers gave greater effects.

New, optically active phosphine oxazoline (JM-Phos) ligands: syntheses and applications in allylation reactions

Three different syntheses of the phosphine oxazoline systems 1 are presented. Two of these approaches are divergent routes designed to involve an advanced intermediate that can be transformed into several different end-products. The third is a shorter route specifically designed to facilitate preparations of these systems on a larger scale using minimal functional group protection. Overall, eight different phosphine oxazolines were prepared. These were screened in several palladium-mediated allylation reactions. They proved to be most useful for asymmetric alkylation of 3-acetoxy-1,3-diphenylpropene and less suitable/effective for the more challenging substrates (a pentenyl derivative and a cyclohexenyl system). X-ray crystallographic analysis of the complex [(eta 3-PhCHCHCHPh)Pd(1a)][PF6] led to the conclusion that the origins of asymmetric induction in these systems might be indirectly attributed to interaction of the oxazoline-phenyl substituent with the palladium and with an allyl-phenyl substituent. Finally, data is presented for allylation of a silylenolate of an N-acyl oxazolidinone; excellent enantioselectivities and yields were obtained.

A rigid linker-scaffold for solid-phase synthesis of dimeric pharmacophores

Bifunctional linker-scaffolds (compounds 1-3) were designed to meet several criteria for solid-phase syntheses of bivalent ligands. They have two amine-functionalized arms that can be differentially protected. Elaboration of these arms could give ligand-pharmacophore dimers wherein the two active components are held reasonably rigidly at around 10 A separation. Their bifunctional design also enables reactions of libraries with libraries to amplify diversity in a truly combinatorial fashion. Molecules 1-3 are also designed so that cleavage of the linker liberates the scaffold entity into solution under conditions that create only byproducts that should not interfere with biological assays. Thus they contain 2-nitrobenzene sulfonamide components that cleave in the presence of good nucleophiles. In the event, the linker-scaffolds 1-3 were prepared (Schemes 1 and 2). The N-benzyl system 2 was shown to have good stability to the types of conditions that might be used to functionalize the scaffold arms and to be sufficiently labile to the cleavage nucleophile (vide infra). The nucleophiles generally used to cleave nitrobenzene sulfonamides either generate undesirable byproducts (thiophenol or alkane thiols) or proved to be insufficiently reactive for the required solid-phase transformations (n-propylamine). However, sodium sulfide was investigated as a new alternative and shown to be a highly reactive cleavage agent that gives only volatile byproducts and sodium hydroxide. It is suggested that sodium sulfide is a highly desirable nucleophile for cleavage of 2-nitrobenzene sulfonamides, in general. The linker-scaffolds 1-3 were used to prepare a small library of bivalent ligands targeted to a protein receptor having charged cavities separated by approximately 10 A. These systems were made from guanidine, pyridinium, carboxylic acid, and sulfonic acid constituents (Tables 1 and 2).

DiSSiMiL: Diverse Small Size Mini-Libraries applied to simple and rapid epitope mapping of a monoclonal antibody

Methods for screening protein-protein interactions are useful in protein science and for the generation of drug leads. We set out to develop a simplified assay to rapidly test protein-protein interactions, with a library of 400 pentapeptides comprising the 20 natural amino acids at two variable positions followed by three glycines (NH2-X1X2GGG). The library was used to identify the epitope of monoclonal antibody (mAb) 10D11 directed against the HOXD4 protein. Three pentapeptide 'hits' were selected (VYGGG, PWGGG and WKGGG) from direct binding assays screening for pentapeptide-mAb interactions; and from assays using pentapeptides in solution to competitively block HOXD4-mAb interactions. Alignment of the three 'hit' pentapeptides to the HOXD4 sequence predicts the mAb 10D11 epitope as NH2-VYPWMK. Synthesis of NH2-VYPWMK hexapeptide confirmed this prediction; and an alanine scan of HOXD4 ablated binding by mAb 10D11 when amino acids in the putative epitope were mutated. We propose that these simplified but diverse libraries can be used for rapid epitope mapping of some mAbs, and for generating lead small peptide analogs that interfere with receptor-ligand or other protein-protein interactions, or with enzymatic activity.

Treatment of immune-mediated hemolytic anemia in dogs with cyclophosphamide

A review of 60 cases of immune-mediated hemolytic anemia (IMHA) in the dog was performed in order to characterize the disease and to identify potential prognostic indicators. Dogs ranged in age from 1 to 13 years, with a mean age of 6.5 years. The 2 most commonly affected breeds were Cocker Spaniels and Labrador Retrievers. Fifty-two of the 60 dogs tested (87%) were autoagglutination positive and spherocytes were present in 45 (75%). Forty-one (89%) of 46 patients tested positive for the presence of immunoglobulin on the red blood cell surface (Coombs assay). The most common clinical signs at presentation were lethargy, weakness, pale mucous membranes, icterus, hemoglobinuria, and anorexia. PCV less than 25% was present in 59 (98%) dogs. At the time of presentation, 35 dogs (58%) had a nonregenerative anemia, whereas 25 patients (42%) had a regenerative response. Thrombocytopenia was seen in 41 (68%) dogs. Nine of 34 dogs (26%) had a prolonged prothrombin time, 19 of 34 (56%) had a prolonged activated partial thromboplastin clotting time, and 12 of 34 (35%) had abnormal fibrinogen concentrations. All dogs received prednisone at immunosuppressive doses (2.2-4.4 mg/kg PO as a single or divided dose every 24 hours) and cyclophosphamide as primary therapy. Forty-one dogs (63%) received cyclophosphamide at 50 mg/m2 q24h for 4 days, whereas 9 dogs (15%) received an initial high dose (200 mg/m2) followed by 3 days of a lower dose (50 mg/m2 q24h). No statistical difference in survival times was found for either protocol. Thirteen dogs were treated with azathioprine in addition to cyclophosphamide and prednisone. The median survival time of dogs that received all 3 drugs was 370 days as compared to 9 days for those dogs that were treated with cyclophosphamide and prednisone alone. Thirty-one (52%) dogs died from the disease, 13 (22%) dogs were alive, and 15 (25%) dogs were lost to follow-up. The median length of survival for all dogs was 21 days. Eight dogs that were discharged from the hospital suffered a relapse (PCV < 25%).

4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyes modified for extended conjugation and restricted bond rotations

Five new, constrained, aryl-substituted 4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene (BODIPY) dyes (3f,g and 4h-j) were prepared and investigated to see if they have more favorable fluorescence characteristics than the unconstrained systems 2 that were prepared in previous studies. Dye types 3 and 4 have relatively rigid conformations caused by the heteroatom (3f and 3g) or ethylene bridge (4h-j) linkers that preclude free rotation of the substituted-benzene molecular fragments. In the event, the new dye types 3 and 4 have longer lambda(max abs) (620-660 nm) and lambda(max)(fluor) (630-680 nm) values than compounds 2. They also exhibit higher extinction coefficients (>100 000 M(-1) cm(-1), except for 3g). Their fluorescent quantum yields are high (up to 0.72 for 4j), with the exception of compound 3g, which has a quantum yield of only 0.05. The redox properties of dyes 3 and 4 have also been examined.

Solution- and solid-phase syntheses of substituted guanidinocarboxylic acids

A library of guanidine-based compounds was produced to mimic the lead compound 1, which is a substance known to have intensely sweet-taste characteristics. Libraries of guanidinocarboxylic acids were therefore prepared via two synthetic methods. The solid-phase method involving trapping of solution-phase carbodiimides by supported amines was used to produce N,N'-dialkyl derivatives (Scheme 1). The second solid-phase method, featuring supported carbodiimides and solution-phase amines (Scheme 2), was devised to prepare N,N'-disubstituted and N,N',N'-trisubstituted guanidinocarboxylic acids. A small collection of guanadinoacetic acid dimers and trimers was also prepared, but this time via a solution-phase coupling of carbodiimides to a polyamine linker.

Resin effects in solid phase S(n)Ar and S(n)2 macrocyclizations

Seven different supports were compared in solid-phase S(N)Ar and S(N)2 macrocyclization reactions. Product purities were assayed for a relatively facile ring-closure process to give products 1 and 3. Some less-facile ring-closure reactions give the undesired dimeric macrocyclization by-products 2; some of these more-demanding ring closures were also examined. Finally, experiments were performed to gauge the rate of cyclizations on different resins, and some qualitative data were obtained for this.

A designed peptidomimetic agonistic ligand of TrkA nerve growth factor receptors

A proteolytically stable small molecule beta-turn peptidomimetic, termed D3, was identified as an agonist of the TrkA neurotrophin receptor. D3 binds the Ig-like C2 region of the extracellular domain of TrkA, competes the binding of another TrkA agonist, affords selective trophic protection to TrkA-expressing cell lines and neuronal primary cultures, and induces the differentiation of primary neuronal cultures. These results indicate that a small beta-turn peptidomimetic can activate a tyrosine kinase neurotrophin receptor that normally binds a relatively large protein ligand. Agents such as D3 that bind the extracellular domain of Trk receptors will be useful pharmacological agents to address disorders where Trk receptors play a role, by targeting populations selectively.

Solid-phase SN2 macrocyclization reactions to form beta-turn mimics

[formula: see text] Efficient solid-phase SN2 macrocyclization reactions were sought to facilitate preparations of focused libraries of beta-turn mimetics. A very efficient, but undesired, cyclization reaction to give five-membered ring lactams 4 was identified in attempts to use O-nucleophiles. Subsequent studies focused exclusively on S-nucleophiles. These reactions gave the desired macrocyclization products 1 in high purities and good overall yields. Conformational analyses of illustrative macrocyclization products 1 via NMR, CD, and molecular simulations showed that they seem to sample both type I and type II beta-turn conformations in solution. CD studies indicate a curious relationship between the preferred conformation and the amino acids encapsulated in the macrocycles.

An allylic/acyclic adenosine nucleoside triphosphate for termination of DNA synthesis by DNA template-dependent polymerases

An allylic adenosine triphosphate analog (AATP) was tested as a substrate for commercially available DNA polymerases. All but one of the enzymes assayed incorporated AATP opposite thymidine (T) with concomitant termination of the elongation reaction. A concentration of only 1 microM was sufficient for complete termination of the polymerization reaction for a short template mediated by Ampli Taq DNA polymerase FS (Taq FS). This result suggests that AATP could be used as a 2',3'-dideoxyadenosine-5'-triphosphate (ddA) surrogate. Kinetics of incorporation revealed that AATP was 48 times less efficiently incorporated than ddA. Furthermore, AATP was used in dye-primer sequencing as a substitute for ddA.

Synthesis of fluorescent, photolabile 3'-O-protected nucleoside triphosphates for the base addition sequencing scheme

The dansylated nucleoside triphosphates 1a and 1b were prepared as a prelude to investigating sequencing of DNA via a scheme that does not involve electrophoresis.

Synthesis of aminobenzoic Acid-based nonpeptide templates: applications in peptidomimetic drug discovery

2,3-Methanoamino acids resemble protein amino acids. The only difference between these groups of compounds is that the former have one additional carbon which spans the α- and β atoms (Fig. 1). This cyclopropane ring constraint of 2,3-methanoamino acids allows four side chain orientations; different conformations are therefore favored when stereoisomeric cyclopropane amino acids are incorporated into peptide sequences. Peptidomimetics containing 2,3-methanoamino acids are also more hindered, and this imparts proteolytic stability (1-4). Overall, both these factors (i.e., the conformational constraints and enhanced proteolytic stabilities, make 2,3-methanoamino acids excellent probes for medicinal chemistry and biophysical experiments.) Fig. 1. Leu and the four stereoisomers of cyclo-Leu.

Elimination of residual natural nucleotides from 3'-O-modified-dNTP syntheses by enzymatic mop-up

Here, we describe a novel strategy called enzymatic "Mop-Up" that efficiently removes contaminating dNTPs from reverse-phase, high-performance liquid chromatography (RP-HPLC) purified 3'-O-modified dNTP syntheses. Enzymatic mop-up takes advantage of the high selectivity of DNA polymerases for the former nucleoside triphosphates over the latter nucleotide analogs. We demonstrate the selective removal of contaminating dATP and dTTP from RP-HPLC purified 3'-O-methyl-dATP and 3'-O-(2-nitrobenzyl)-dTTP syntheses, respectively. These data highlight the importance of natural nucleotide contamination when interpreting enzymatic incorporation data and provide an alternative hypothesis for the observed property of catalytic editing of DNA polymerases. Moreover, the effective removal of natural nucleotides from 3'-O-modified analogs addresses the important issue of nucleotide read-through for stop-start DNA sequencing strategies, such as the base addition sequencing scheme (BASS).

Linkage of the MHC to familial multiple sclerosis suggests genetic heterogeneity. The Multiple Sclerosis Genetics Group

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system. While its etiology is not well understood, genetic factors are clearly involved. Until recently, most genetic studies in MS have been association studies using the case-control design testing specific candidate genes and studying only sporadic cases. The only consistently replicated finding has been an association with the HLA-DR2 allele within the major histocompatibility complex (MHC) on chromosome 6. Using the genetic linkage design, however, evidence for and against linkage of the MHC to MS has been found, fostering suggestions that sporadic and familial MS have different etiologies. Most recently, two of four genomic screens demonstrated linkage to the MHC, although specific allelic associations were not tested. Here, a dataset of 98 multiplex families was studied to test for an association to the HLA-DR2 allele in familial MS and to determine if genetic linkage to the MHC was due solely to such an association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta) in the MHC demonstrated strong genetic linkage (parametric lod scores of 4.60, 2.20 and 1.24, respectively) and a specific association with the HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results by HLA-DR2 status showed that the linkage results were limited to families segregating HLA-DR2 alleles. These results demonstrate that genetic linkage to the MHC can be explained by the HLA-DR2 allelic association. They also indicate that sporadic and familial MS share a common genetic susceptibility. In addition, preliminary calculations suggest that the MHC explains between 17 and 62% of the genetic etiology of MS. This heterogeneity is also supported by the minority of families showing no linkage or association with loci within the MHC.

A labeled guanidine ligand for studying sweet taste

A synthesis of a biotinylated-, coumarin-substituted-N,N'-diarylguanidine 1 is reported. This ligand has structural features conducive to studying sweet taste including a fluorescent tag to facilitate spectroscopic studies of binding to protein-receptors for sweet ligands and an anchor for affinity purification.

Test of the potential of a dATP surrogate for sequencing via MALDI-MS

1-(2'-Deoxy-beta-d-ribofuranosyl)-3-nitropyrrole phosphate was incorporated into a DNA decamer and analyzed via matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). The extent and composition of the various fragment peaks were compared with those in the MALDI-MS spectrum of dT4AT5. The nitropyrrole-containing oligomer proved to be more robust. Two different DNA template assays were then used to attempt to identify DNA replicating enzymes that would incorporate the corresponding triphosphate, i.e. 1-(2'-deoxy-beta-d-ribofuranosyl)-3-nitropyrrole triphosphate (dXTP). It was shown that dXTP was not incorporated by some enzymes and it inhibited others. However, DNA polymerase I Klenow fragment and avian myeloblastosis virus reverse transcriptase incorporated dXTP in place of dATP and then replicated the template overhang in the usual way. The potential of dXTP as a surrogate for dATP in DNA sequencing with MALDI-MS analysis is discussed.

The development and benefits of nursing protocols for fractured neck of femur patients

In this article the authors discuss the development, use and auditing of nursing care protocols, which have been implemented and form a guide for nurses caring for patients with fractured neck of femur in Southend Health Care NHS Trust. The development of these protocols occurred after an initial medical audit, which was followed by a far larger multidisciplinary audit, and both of these revealed there was need for changes in the clinical management of such patients; subsequently a large multidisciplinary working group worked together to develop care protocols/pathways to enable closure of the audit loop. The reasons for focusing on fractured neck of femur as a high priority condition are also discussed. All professional groups caring for these patients were involved in the multidisciplinary working group, which was formed to close the audit loop and to improve clinical practices by increasing the systemization and coordination of care. The development of the nursing protocols represented an extremely important part of this process, and the care of about 700 patients was examined during this work. The audit and associated subsequent work have resulted in direct improvements to both patient care and health outcomes, and the authors conclude that there is great value in developing multidisciplinary protocols, particularly those involving nurses, because they spend more time with patients whilst they are in hospital than any other professional group. The benefits of these nursing protocols have been multifold, in particular they have facilitated a clearer flow of patients through the hospital, increased awareness of responsibilities and reduced duplication of effort, and ensured patients receive the best possible care over the 24-hour period.

Comparisons of the conformational biases imposed by trans-2,3-methanomethionine and alpha-methylmethionine

A comparative study of four peptidomimetics of the sequence Phe-Met-Arg-Phe-amide (FMRFa) was performed to compare the conformational bias caused by trans-2,3-methanomethionine and alpha-methylmethionine stereoisomers. The specific compounds studied were {(2S,3S)-cyclo-M} RFa, F{(2R,3R)-cyclo-M} RFa, F{(S)-alpha-Mem} RFa, and F{(R)-alpha-MeM} RFa. Molecular simulations based on CHARMm 22 indicate that gamma-turn, inverse gamma-turn, and alpha-helical conformations about the cyclo-M residue are accessible to the two F{cyclo-M} RFa stereoisomers. Similar calculations for F{(S)-alpha-MeM} RFa, and F{(R)-alpha-MeM}RFa indicate that the alpha-methylamino acids tend to favor alpha-helical conformations. The nmr data is presented for the four peptidomimetics. Most informative were the rotating frame nuclear Overhauser effect cross peaks between the NH protons proximal to the methionine surrogates, and the C beta hydrogens. Overall, these nmr data indicate F{(2S,3S)-cyclo-M} RFa and F{(2R,3R)-cyclo-M} RFa preferentially adopt inverse gamma-turn and gamma-turn conformations, respectively, whereas F{(S)-alpha-MeM} RFa and F{(R)-alpha-MeM} RFa tend to form partial left- and right-handed helical structures (although energy differences between the two turn structures, and between the two helical structures are likely to be small). It is suggested that the wider NH-C alpha-CO angle of cyclopropane amino acids and their more severe steric requirements around the C beta carbons force the peptidomimetic N- and C-termini into the same region of conformational space. This favors C7 turns in the cyclopropane amino acid series relative to the less constrained alpha-methyl derivatives.

Libraries of opiate and anti-opiate peptidomimetics containing 2,3-methanoleucine

A library of 96 peptides/peptidomimetics was prepared, in which half was based on the YGGFL-NH2 sequence, while the remainder were derivatives of a presumed anti-opiate peptide, YGGFLRF-NH2. Of the 48 compounds in each half of the library, 32 contained a stereoisomer of 2,3-methanoleucine substituted for Leu5. Binding of the YGGFL-NH2 derivatives to the mu- and delta-opioid receptors, and to the anti-beta-endorphin monoclonal antibody (clone 3E7), indicated any change at the Leu5 had little effect on the binding when compared with modifications to the YGGF-sequence. Conversely, cyclo-Leu residues did alter the binding of YGGFLRF-NH2 derivatives when substituted for Leu5. Of these 32 peptidomimetics, three derivatives of 2S,3S-cyclo-Leu had relatively low Ki values for binding to an NPFF receptor. Differences between the outcome of the screens were interpreted in terms of the position of the cyclo-Leu residue in the two sequences.