Mycobacterium abscessus causes disease in patients with structural abnormalities of the lung, and it is an emerging pathogen in patients with cystic fibrosis. Colonization of the airways by nontuberculous mycobacteria is a harbinger of invasive lung disease. Colonization is facilitated by biofilm formation, with M. abscessus glycopeptidolipids playing an important role. M. abscessus can transition between a noninvasive, biofilm-forming, smooth colony phenotype that expresses glycopeptidolipid, and an invasive rough colony phenotype that expresses minimal amounts of glycopeptidolipid and is unable to form biofilms. The ability of this pathogen to transition between these phenotypes may have particular relevance to lung infection in cystic fibrosis patients since the altered pulmonary physiology of these patients makes them particularly susceptible to colonization by biofilm-forming bacteria. In this study we demonstrate that rough variants of M. abscessus stimulate the human macrophage innate immune response through TLR2, while smooth variants do not. Temperature-dependent loss or physical removal of glycopeptidolipid from the cell wall of one of the smooth variants leads to TLR2 stimulation. This response is stimulated in part through phosphatidyl-myo-inositol mannosides that are present in the cell wall of both rough and smooth variants. Mannose-binding lectins bind to rough variants, but lectin binding to an isogenic smooth variant is markedly reduced. This suggests that glycopeptidolipid in the outermost portion of the M. abscessus cell wall masks underlying cell wall lipids involved in stimulating the innate immune response, thereby facilitating colonization. Conversely spontaneous “unmasking” of cell wall lipids may promote airway inflammation.

Lavender Foal Syndrome (LFS) is a lethal inherited disease of horses with a suspected autosomal recessive mode of inheritance. LFS has been primarily diagnosed in a subgroup of the Arabian breed, the Egyptian Arabian horse. The condition is characterized by multiple neurological abnormalities and a dilute coat color. Candidate genes based on comparative phenotypes in mice and humans include the ras-associated protein RAB27a (RAB27A) and myosin Va (MYO5A). Here we report mapping of the locus responsible for LFS using a small set of 36 horses segregating for LFS. These horses were genotyped using a newly available single nucleotide polymorphism (SNP) chip containing 56,402 discriminatory elements. The whole genome scan identified an associated region containing these two functional candidate genes. Exon sequencing of the MYO5A gene from an affected foal revealed a single base deletion in exon 30 that changes the reading frame and introduces a premature stop codon. A PCR–based Restriction Fragment Length Polymorphism (PCR–RFLP) assay was designed and used to investigate the frequency of the mutant gene. All affected horses tested were homozygous for this mutation. Heterozygous carriers were detected in high frequency in families segregating for this trait, and the frequency of carriers in unrelated Egyptian Arabians was 10.3%. The mapping and discovery of the LFS mutation represents the first successful use of whole-genome SNP scanning in the horse for any trait. The RFLP assay can be used to assist breeders in avoiding carrier-to-carrier matings and thus in preventing the birth of affected foals.

SummaryHorses, like many domesticated species, have been selected for broad variation in skeletal size. This variation is not only an interesting model of rapid evolutionary change during domestication, but is also directly applicable to the horse industry. Breeders select for complex traits like body size and skeletal conformation to improve marketability, function, soundness and performance in the show ring. Using a well-defined set of 35 measurements, we have identified and quantified skeletal variation in the horse species. We collected measurements from 1215 horses representing 65 breeds of diverse conformation such as the American Miniature, Shetland Pony, Arabian Horse, Thoroughbred, Shire and Clydesdale. Principal components analysis has identified two key dimensions of skeletal variation in the horse. Principal component 1 is positively correlated with every measurement and quantifies overall body size. Principal component 2 captures a pattern of bone widths vs. lengths and thus quantifies variation in overall bone thickness. By defining these complex skeletal traits, we have created a framework for whole genome association studies to identify quantitative trait loci that contribute to this variation.

Mycobacterium tuberculosis, the causative agent of tuberculosis, is unique among bacterial pathogens in that it contains a wide array of complex lipids and lipoglycans on its cell wall. Among them, the sulfated glycolipid, termed sulfolipid is thought to mediate specific host pathogen interactions during infection. Sulfolipids (SLs) including sulfolipid I (SL-I) and sulfolipid II (SL-II) are 2,3,6,6'-tetraacyltrehalose 2'-sulfates. SL-I was identified as a family of homologous 2-palmitoyl(stearoyl)-3-phthioceranoyl, 6,6'-bis(hydroxyphthioceranoy1)-trehalose 2'-sulfate and was believed to be the principal sulfolipid of Mycobacterium tuberculosis strain H37Rv. We cultured and extracted sulfolipids using various conditions including those originally described and employed high-resolution multiple-stage linear ion-trap mass spectrometry with electrospray ionization to characterize the structure of the principal SL. We revealed that SL-II, a family of homologous 2-stearoyl(palmitoyl)-3,6,6'-tris(hydroxyphthioceranoy1)-trehalose2'-sulfates, rather than SL-I is the principal sulfolipid class. We identified a great number of isomers resulting from permutation of the various hydroxyphthioceranoyl substituents at 6- and 6'-position of the trehalose backbone for each of the SL-II species in the entire family. We redefined the structure of this important lipid family that was mis-assigned using the traditional methods 40 years ago.

Equine obesity can cause life-threatening secondary chronic conditions, similar to those in humans and other animal species. Equine metabolic syndrome (EMS), primarily characterized by hyperinsulinemia, is often present in obese horses and ponies. Due to clinical similarities to conditions such as pituitary pars intermedia dysfunction (formerly equine Cushing's disease), conclusive diagnosis of EMS often proves challenging. Aside from changes in diet and exercise, few targeted treatments are available for EMS, emphasizing the need for early identification of at-risk individuals to enable implementation of preventative measures. A genomewide association study (GWAS) using Arabian horses with a history of severe laminitis secondary to EMS revealed significant genetic markers near a single candidate gene () that may play a role in cholesterol homeostasis. The best marker, BIEC2-263524 (chr14:69276814 T > C), was correlated with elevated insulin values and increased frequency of laminitis ( = 0.0024 and = 9.663 × 10, respectively). In a second population of Arabian horses, the BIEC2-263524 marker maintained its associations with higher modified insulin-to-glucose ratio (MIRG) values ( = 0.0056) and BCS ( = 0.0063). Screening of the predicted coding regions by sequencing identified a polymorphic guanine homopolymer and 5 haplotypes in the 3' untranslated region (UTR). An 11 guanine (11-G) allele at was correlated with elevated insulin values in the GWAS population ( = 0.0008) and, in the second population, elevated MIRG and increased BCS > 6.5 ( = 0.0055 and = 0.0162, respectively). The BIEC2-263524-C and the 3' UTR -11(G) polymorphisms were correlated at a 98% frequency, indicating strong linkage disequilibrium across this 150-kb haplotype. Assays for these markers could diagnose horses with a genetic predisposition to develop obesity. Additionally, discovery of FAM174A function may improve our understanding of the etiology of this troubling illness in the horse and warrants investigation of this locus for a role in metabolic- and obesity-related disorders of other species.

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AimsTwelve GP surgeries refer adults with suspected ADHD to Horsham Assessment and Treatment Service (ATS). Patients are referred by GPs via letter and an adult ADHD self-report scale (ASRS). Letter contents are variable and some referrals are rejected. There is no gold standard or national guideline for what referral information is required. We used a combination of guidelines and advice from The Royal College of Psychiatrists, The National Institute for Health and Care Excellence, and ADHD UK. Aims: to evaluate the current quality of the referrals, to obtain GP’' views on the referral process, to make the process more efficient and clearer, and with that improve patient experience.MethodsA retrospective data collection method was used. 57 patients were referred between 31st August 2021 and 1st April 2022. We reviewed 54 referral letters (3 were excluded). Main information looked for: presenting difficulties, resultant impairments, confirmation some symptoms present in childhood, past medical history, family history and if an ASRS was attached. We sent a questionnaire to obtain GPs’ opinions on the referral process and how to improve this.ResultsResults of reviewing referral letters: •89% of referrals explained the current difficulties•52% described the resultant impairments•61% of referrals mentioned if symptoms had been present in childhood•91% of referrals contained past medical history and current medication•No referrals mentioned family history•6% of referrals contained some physical health data•85% of referrals to ATS were accepted; 13% rejected as ASRS not attached.Results from GP questionnaires: 11 surveys were returned. Most GPs were not confident in making a referral or what information is required, and did not understand the referral process. GPs would like a referral form, a flowchart outlining the referral process and information for patients about ADHD assessment.Conclusion89% of referrals explained current difficulties. Just over half described the resultant impairments, and confirmed if there were symptoms in childhood. Most referrals contained past medical history. 6% contained some physical health data. Only 85% of referrals were accepted. GPs would like a referral form, a flowchart and information for patients.Results were distributed to staff in ATS and we will distribute results to GPs. We have created a referral form and flowchart to make the referral process more efficient and clearer, and to improve patient experience. We will re-evaluate this after a few weeks, so we can compare with previous data collected.

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