Hypocobalaminaemia in dogs with acute gastrointestinal diseases

OBJECTIVES

The objectives of this study were to investigate the prevalence of hypocobalaminaemia in dogs with acute gastrointestinal diseases and to evaluate its relationship with disease severity and outcome.

MATERIALS AND METHODS

Medical records of dogs presented for acute gastrointestinal signs that a serum cobalamin concentration measured between September 2019 and 2021 were included in this study. Hypocobalaminaemia was defined as serum cobalamin concentration <200 pmol/L, and low-normal cobalamin was defined as serum cobalamin concentration of 200 to 295 pmol/L. Duration of clinical signs prior to presentation, Acute Patient Physiologic and Laboratory Evaluation (APPLE) fast score, length of hospitalisation and outcome were recorded.

RESULTS

Thirty-three dogs were included. Seventeen dogs were diagnosed with acute gastrointestinal disease of unknown aetiology, seven dogs with parvoviral enteritis, three dogs with acute haemorrhagic diarrhoea syndrome and six dogs with miscellaneous diseases. The prevalence of hypocobalaminaemia in this population was 30.3% and low-normal cobalamin concentration was detected in 18.2% of dogs. There was no statistically significant relationship between the detection of hypocobalaminaemia or low-normal cobalamin and the duration of clinical signs before presentation, length of hospitalisation or Acute Patient Physiologic and Laboratory Evaluation fast score on admission. Mortality rate was 3%.

CLINICAL SIGNIFICANCE

Hypocobalaminaemia and low-normal cobalamin are common findings in dogs with acute gastrointestinal diseases. The therapeutic significance and potential implications for prognosis of hypocobalaminaemia in these patients requires further investigation.

Australian dermatologists' prescribing behaviours for male androgenetic alopecia

Androgenetic alopecia (AGA) is highly prevalent among Australian men and can have significant psychological impacts. Despite its prevalence, treatment options have traditionally been limited. In this study, we examined the current prescribing patterns of Australian dermatologists for male AGA.

Bone Union Assessment with Computed Tomography (CT) and Statistical Associations with Mechanical or Histological Testing: A Systematic Review of Animal Studies

Objective and accurate assessment of bone union after a fracture, arthrodesis, or osteotomy is relevant for scientific and clinical purposes. Bone union is most accurately imaged with computed tomography (CT), but no consensus exists about objective assessment of bone union from CT images. It is unclear which CT-generated parameters are most suitable for bone union assessment. The aim of this review of animal studies is to find which CT-generated parameters are associated most strongly with actual bone union. Scientific databases were systematically searched. Eligible studies were studies that (1) were animal studies, (2) created a fracture, (3) assessed bone union with CT, (4) performed mechanical or histological testing as measure of actual bone union, and (5) associated CT-generated outcomes to mechanical or histological testing results. Two authors selected eligible studies and performed risk of bias assessment with QUADAS-2 tool. From 2567 studies that were screened, thirteen studies were included. Most common CT parameters that were investigated were bone mineral density, bone volume, and total callus volume. Studies showed conflicting results concerning the associations of these parameters with actual bone union. CT-assessed torsional rigidity (assessed by three studies) and callus density (assessed by two studies) showed best results. The studies investigating these two parameters reported moderate to strong associations with actual bone union. CT-assessed torsional rigidity and callus density seem the most promising parameters to represent actual bone union after a fracture, arthrodesis, or osteotomy.Prospero trial registration number: CRD42020164733.

Prevalence and Associations of General Practice Registrars' Management of Atopic Dermatitis: A Cross-Sectional Analysis from the Registrar Clinical Encounters in Training Study

Introduction

Atopic dermatitis (AD) is a chronic inflammatory condition which imposes substantial burden upon patients and their families. As a frequent primary care presentation, general practice (GP) trainees must develop adequate skills in AD diagnosis and management.

Objectives

We aimed to explore the prevalence and associations of GP registrars' management of patients with AD.

Methods

This study used data from the Registrar Clinical Encounters in Training (ReCEnT) project, an ongoing cohort study of the clinical and educational experience of Australian GP registrars. Registrar, patient, and consultation factors were independent variables in multivariable logistic regression with outcome factor 'diagnosis/problem being AD'.

Results

From 2010-2019, 2,783 registrars (96% response rate) provided data from 381,180 consultations. AD was encountered in 0.6% of consults. AD was more likely to be seen in patients aged 0-1 years and patients from a non-English speaking background. AD was less likely to be seen in Aboriginal or Torres Strait Islander patients. Learning goals were more likely to be generated for AD and these consultations were associated with registrars seeking information or assistance. AD was strongly associated with a medication being prescribed, of which the most prescribed medications were mild or moderate potency topical corticosteroids.

Conclusions

Our findings suggest that, similar to other dermatological presentations, registrars find AD challenging to manage. There may be some gaps in AD management knowledge and application.

Alopecias in humans: biology, pathomechanisms and emerging therapies

BACKGROUND

The hair follicle is a complete mini-organ with a complex biology. Recent discoveries have shed light on the pathogenesis and genetic basis of a number of hair loss conditions, offering novel treatment alternatives.

OBJECTIVE

To explore the biology and physiology of hair growth, the pathomechanism behind alopecias and emerging therapies.

CONCLUSION AND CLINICAL IMPORTANCE

Hair growth is influenced by numerous physiological moderators. Greater understanding of the biology and physiology of the hair follicle and the pathomechanisms of hair disease facilitates development of targeted treatments. Sublingual minoxidil is a promising therapy in humans where optimised drug delivery enhances efficacy and reduces systemic adverse effects. Janice kinase inhibitors, which disrupt the inflammatory cascade, help maintain the hair follicle, preserve immune privilege, and regrow hair in alopecia areata. As the pathomechanisms of other forms of alopecia become better understood, new targeted therapies with greater efficacy will emerge.

General Practice Registrars' Management of and Specialist Referral Patterns for Atopic Dermatitis

Background

Atopic dermatitis (AD) is a common presentation in the general practice (GP) setting. Implementation of appropriate referral pathways is instrumental for best patient care and is an essential skill for Australian GP registrars.

Objectives

We aimed to explore the prevalence and associations of GP registrar referrals to specialists for AD management.

Methods

A cross-sectional analysis utilizing data from the Registrar Clinical Encounters in Training (ReCEnT) project, an ongoing cohort study that documents in-consultation clinical and educational experience of Australian GP registrars. Registrar, patient, and consultation factors associated with referrals for AD were established using logistic regression.

Results

A total of 2,783 registrars (96% response rate) provided data from 381,180 consultations from 2010 to 2019. A total of 3,285 (0.55%) of 595,412 diagnoses managed were AD, of which 222 (6.8%) resulted in referral. Of these referrals, 70% were to dermatologists, 17% to allergists/immunologists, and 10% to pediatricians. Associations of referral included registrar female gender, patient age, longer consultation duration; an established (rather than new) AD diagnosis; supervisor advice being sought; and learning goals being generated.

Conclusions

Both registrar and patient factors influence AD referral patterns. Registrars referred established rather than newly diagnosed AD, suggesting a level of comfort in initial management. Referral was associated with longer consultations, seeking supervisor advice, and generation of learning goals-suggesting these are more complex presentations and, possibly, registrar learning opportunities. A significant proportion of referrals were to non-dermatologist specialists. The implication of this for optimal patient care is a subject for further study.

[The role of the context in dealing with aggression of psychiatric patients with mild intellectual disabilities]

Mild intellectual disabilities (mid) are underdiagnosed in psychiatric institutions. Aggression is a problem in patients with mid admitted in psychiatric institutions.<br/> AIM: To clarify the background of aggression problems and to give advice on how to prevent them.<br/> METHOD: Discussion of the literature and practical experience.<br/> RESULTS: Agression problems are not only a correlate of the mid but are interrelated with the interpersonal style and personal characteristics of the staff involved in the treatment process, the living group climate, the working climate and the characteristics of the organization.<br/> CONCLUSION: By taking in account all these features the treatment of aggression and diminishing of aggressive incidents of patients with mid admitted in psychiatric institutions can be dealt with in a more effective way.

Embryonal Rhabdomyosarcoma of the Oesophagus in a Young Dog

A 15-month-old great Dane dog, showing clinical signs related to hypertrophic osteopathy, was diagnosed radiographically with a mass in the region of the thoracic oesophagus. Exploratory thoracotomy revealed an extensive, highly vascularized and locally invasive oesophageal mass and the presence of nodules in adjacent lung lobes. The dog was humanely destroyed intra-operatively. Histological examination revealed that the mass was an embryonal rhabdomyosarcoma. This is the first report of rhabdomyosarcoma of the oesophagus of a dog. Rhabdomyosarcoma should be considered a differential diagnosis when a mass adjacent to the oesophagus is diagnosed.

Results of Screening of Apparently Healthy Senior and Geriatric Dogs

Background

There is a growing interest in health care of elderly dogs; however, scientific information about physical and laboratory examination findings in this age group is limited.

Objectives

To describe systolic blood pressure (SBP), and results of physical examination and laboratory tests in senior and geriatric dogs that were judged by the owner to be healthy.

Animals

Hundred client‐owned dogs.

Methods

Dogs were prospectively recruited. Owners completed a questionnaire. SBP measurement, physical, orthopedic and neurologic examination, direct fundoscopy and Schirmer tear test were performed. Complete blood count, serum biochemistry, and urinalysis were evaluated.

Results

Forty‐one senior and 59 geriatric dogs were included. Mean SBP was 170 ± 38 mmHg, and 53 dogs had SBP > 160 mmHg. Thirty‐nine animals were overweight. A heart murmur was detected in 22, severe calculus in 21 and 1 or more (sub)cutaneous masses in 56 dogs. Thirty‐two dogs had increased serum creatinine, 29 hypophosphatemia, 27 increased ALP, 25 increased ALT, and 23 leukopenia. Crystalluria, mostly amorphous crystals, was commonly detected (62/96). Overt proteinuria and borderline proteinuria were detected in 13 and 18 of 97 dogs, respectively. Four dogs had a positive urine bacterial culture. Frequency of orthopedic problems, frequency of (sub)cutaneous masses, and platelet count were significantly higher in geriatric compared with senior dogs. Body temperature, hematocrit, serum albumin, and serum total thyroxine concentration were significantly lower in geriatric compared with senior dogs.

Conclusions and Clinical Importance

Physical and laboratory abnormalities are common in apparently healthy elderly dogs. Veterinarians play a key role in implementing health screening and improving health care for elderly pets.

Effects of external rhythmical cueing on gait in patients with Parkinson's disease: a systematic review

Objective: To critically review studies evaluating the effects of external rhythmical cueing on gait in patients with Parkinson's disease.

Methods: Articles published from 1966 to January 2005 were searched by two physiotherapists in MEDLINE, PiCarta, PEDRo, Cochrane, DocOnline, CINAHL and SUMSEARCH. To be included, articles had to investigate the effects of external rhythmical cueing (i.e., auditory, visual or tactile cueing) on gait parameters in patients with idiopathic Parkinson's disease. Both controlled and noncontrolled studies were included. Based on the type of design and methodological quality a meta-analysis or best-evidence synthesis was applied.

Results: Twenty-four studies (total number of patients = 626) out of the 159 screened studies were evaluated in this systematic review. Two out of 24 were randomized controlled trails (RCT), both of high methodological quality. One RCT did not focus specifically on external rhythmical cueing of individual patients with Parkinson's disease, but on group exercises in general, including walking with cues. All other studies were pre-experimental studies. Best-evidence synthesis showed strong evidence for improving walking speed with the help of auditory cues. Insufficient evidence was found for the effectiveness of visual and somatosensory cueing.

Conclusion: Only one high-quality study, specifically focused on the effects of auditory rhythmical cueing, suggesting that the walking speed of patients with Parkinson's disease can be positively influenced. However, it is unclear whether positive effects identified in the laboratory can be generalized to improved activities of daily living (ADLs) and reduced frequency of falls in the community. In addition, the sustainability of a cueing training programme remains uncertain.

A thicker chorion gives ova of Atlantic salmon (Salmo salar L.) the upper hand against Saprolegnia infections

Since the ban of malachite green in the fish farming industry, finding alternative ways of controlling Saprolegnia infections has become of utmost importance. Much effort has been made to elucidate the mechanisms by which Saprolegnia invades fish eggs. Little is known about the defence mechanisms of the hosts, making some eggs more prone to infection than others. One clue might lie in the composition of the eggs. As the immune system in the embryos is not developed yet, the difference in infection levels could be explained by factors influenced by the mother herself, by either transferring passive immunity, influencing the physical aspects of the eggs or both. One of the physical aspects that could be influenced by the female is the chorion, the extracellular coat surrounding the fish egg, which is in fact the first major barrier to be overcome by Saprolegnia spp. Our results suggest that a thicker chorion in eggs from Atlantic salmon gives a better protection against Saprolegnia spp. In addition to the identification of differences in sensitivity of eggs in a fish farm set-up, we were able to confirm these results in a laboratory-controlled challenge experiment.

Peritoneopericardiale hernia diafragmatica met eenmalige pericardiale effusie bij een beagle

Een mannelijke, gecastreerde beagle werd op vierjarige leeftijd aangeboden omwille van ascites, tachypnee, partiële anorexie en lethargie. Via radiografie, echocardiografie en computertomografie werd de hond gediagnosticeerd met pericardiale effusie en een peritoneopericardiale hernia diafragmatica, waarbij vermoedelijk enkel omentum was geherniëerd in het hartzakje. Een abdominocentese en pericardiocentese werden uitgevoerd. De peritoneopericardiale hernia diafragmatica werd niet chirurgisch gecorrigeerd, aangezien er na een eenmalige pericardiocentese geen nieuwe pericardiale effusie ontstond en de patiënt het klinisch goed stelde. Tijdens het controlebezoek, een half jaar na de pericardiocentese, was de patiënt actief en speels en was er nog steeds geen sprake van recidiverende pericardiale effusie.

Saprolegnia diclina IIIA and S. parasitica employ different infection strategies when colonizing eggs of Atlantic salmon, Salmo salar L

Here, we address the morphological changes of eyed eggs of Atlantic salmon, Salmo salar L. infected with Saprolegnia from a commercial hatchery and after experimental infection. Eyed eggs infected with Saprolegnia spp. from 10 Atlantic salmon females were obtained. Egg pathology was investigated by light and scanning electron microscopy. Eggs from six of ten females were infected with S. parasitica, and two females had infections with S. diclina clade IIIA; two Saprolegnia isolates remained unidentified. Light microscopy showed S. diclina infection resulted in the chorion in some areas being completely destroyed, whereas eggs infected with S. parasitica had an apparently intact chorion with hyphae growing within or beneath the chorion. The same contrasting pathology was found in experimentally infected eggs. Scanning electron microscopy revealed that S. parasitica grew on the egg surface and hyphae were found penetrating the chorion of the egg, and re-emerging on the surface away from the infection site. The two Saprolegnia species employ different infection strategies when colonizing salmon eggs. Saprolegnia diclina infection results in chorion destruction, while S. parasitica penetrates intact chorion. We discuss the possibility these infection mechanisms representing a necrotrophic (S. diclina) vs. a facultative biotrophic strategy (S. parasitica).

Towards a framework in interaction training for staff working with clients with intellectual disabilities and challenging behaviour

BACKGROUND

Training support staff in dealing with challenging behaviour in clients with intellectual disabilities (ID) is needed. The goal of this study is to determine which elements need to be incorporated in a training on staff interactions with these clients, building upon a framework and an interpersonal model. As in functional analysis, this study tests the influence of client interpersonal behaviour, three types of staff reactions to challenging behaviour, two types of staff psychological resources and staff team climate on four styles of staff interpersonal behaviour.

METHOD

A total of 318 support staff members completed a questionnaire on staff interpersonal behaviour for 44 clients with ID and challenging behaviour, as well as seven questionnaires on client interpersonal behaviour, staff emotions, attributions, self-efficacy, self-reflection, coping styles and team climate. The influence of these seven factors on four staff interpersonal behaviours was examined using multilevel multiple regression analysis.

RESULTS

Friendly-warm and dominant client interpersonal behaviour had a significant positive impact on friendly and assertive control staff behaviour, respectively. Also, there was a strong influence of staff negative and positive emotions, as well as their self-efficacy, on most of the staff interpersonal behaviours. Staff self-reflection, insight and avoidance-focused coping style had an impact on some staff interpersonal behaviours. Staff team climate only predicted higher support-seeking staff behaviour.

CONCLUSIONS

In conducting a functional analysis of staff interpersonal behaviour, the results of this study can be used both as a framework in staff-client interaction training and in clinical practice for treating challenging behaviour. The emphasis in training and practice should not only be on the bidirectional dynamics of control and affiliation between staff and clients, but also - in order of importance - on the impact of staff emotions, self-efficacy, self-reflection and insight, coping style, team climate and attributions on staff interpersonal behaviour.

Autochthonous Angiostrongylus vasorum infection in a Border collie in Belgium

A nine-month-old, female Border collie was referred to the clinic because of an acute persistent cough and hemoptysis after excitation. Thoracic radiographs revealed a diffuse interstitial to alveolar pattern, compatible with pulmonary hemorrhage. To stabilize the dog and because of a suspected complex coagulopathy and on-going bleeding evidenced by worsening anemia, a fresh frozen plasma transfusion (10 ml/kg over four hours) was administered. Fecal examination confirmed the clinical suspicion of Angiostrongylus vasorum as the underlying cause of all the observed clinical signs. The dog was treated with fenbendazole (50 mg/kg SID) during 21 days. One week after treatment initiation, the dog was clinically healthy and thoracic radiographs showed a marked improvement of the pulmonary lesions. This case illustrates that autochthonous canine A. vasorum infections can occur in Belgium and they should be taken into account in the diagnostic work-up of dogs with respiratory signs and bleeding disorders.

Monitoring of diabetic dogs

Diabetes mellitus is one of the most common endocrine disorders in the dog. Although diagnostics are relatively straightforward, treatment and especially adequate long-term monitoring are challenging. To avoid complications, such as hypoglycemia, weight loss, diabetes ketoacidosis and urinary tract infections, adequate monitoring is indispensable. In this review different monitoring tools, such as history and clinical signs, single and serial blood glucose measurements, glycated blood products, continuous glucose measurements and urine glucose will be evaluated. Because each monitoring technique has its limitations, the challenge for the veterinarian is to use an adequate combination of these tools to obtain a good image of the patient’s glycemic status.

Interprofessional non-technical skills for surgeons in disaster response: a qualitative study of the Australian perspective

Interprofessional non-technical skills for surgeons in disaster response have not yet been developed. The aims of this study were to identify the non-technical skills required of surgeons in disaster response and training for disaster response and to explore the barriers and facilitators to interprofessional practice in surgical teams responding to disasters. Twenty health professionals, with prior experience in natural disaster response or education, participated in semi-structured in-depth interviews. A qualitative matrix analysis design was used to thematically analyze the data. Non-technical skills for surgeons in disaster response identified in this study included skills for austere environments, cognitive strategies and interprofessional skills. Skills for austere environments were physical self-care including survival skills, psychological self-care, flexibility, adaptability, innovation and improvisation. Cognitive strategies identified in this study were "big picture" thinking, situational awareness, critical thinking, problem solving and creativity. Interprofessional attributes include communication, team-player, sense of humor, cultural competency and conflict resolution skills. "Interprofessionalism" in disaster teams also emerged as a key factor in this study and incorporated elements of effective teamwork, clear leadership, role adjustment and conflict resolution. The majority of participants held the belief that surgeons needed training in non-technical skills in order to achieve best practice in disaster response. Surgeons considerring becoming involved in disaster management should be trained in these skills, and these skills should be incorporated into disaster preparation courses with an interprofessional focus.

Localised abdominal compartment syndrome: bladder-over-gastric pressure ratio (B/G ratio) as a clue to diagnosis

INTRODUCTION

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) have been identified as a cause of organ dysfunction and mortality in critically ill patients. The diagnosis of IAH/ACS depends on accurate intra-abdominal pressure (IAP) measurement, which is usually performed via the bladder or the stomach.The aim of this study was to describe cases where intragastric pressure (IGP) and intrabladder pressure (IBP) were measured simultaneously.

PATIENTS AND METHODS

After review of medical records, four patients admitted to our ICU department where both IGP and IBP were measured, could be identified. IGP was measured using the Spiegelberg catheter and IBP was measured using the FoleyManometer LV. In all patients, the bladder-over-gastric pressure ratio (B/G ratio) was calculated.

RESULTS

In two of four patients, IGP and IBP differed significantly. In one patient the B/G ratio was lower than 1 suggesting a diagnosis of epigastric ACS and in one patient B/G ratio was greater than 1 leading to a diagnosis of pelvic ACS. The latter patient was spared a decompressive laparotomy due to the additional IGP measurement and the subsequent diagnosis of localized ACS.

CONCLUSION

The preferred methods for IAP measurement are via the bladder and via the stomach. In some patients, IGP and IBP may differ significantly and this may have clinical implications. Clinicians should be aware of the possibility of localized ACS. In order to identify risk factors and to recommend treatment for localized ACS, further study of simultaneous IGP and IBP measurements are needed.

Multilocus sequence analysis of root nodule isolates from Lotus arabicus (Senegal), Lotus creticus, Argyrolobium uniflorum and Medicago sativa (Tunisia) and description of Ensifer numidicus sp. nov. and Ensifer garamanticus sp. nov

Nine isolates from Argyrolobium uniflorum, Lotus creticus, Medicago sativa (Tunisia) and Lotus arabicus (Senegal) were analysed by multilocus sequence analysis (MLSA) of five housekeeping genes (recA, atpD, glnA, gltA and thrC), the 16S rRNA gene and the nodulation gene nodA. Analysis of the individual and concatenated gene sequences demonstrated that the nine new strains constituted three stable, well-supported (bootstrap and gene sequence similarity values) monophyletic clusters, A, B and C, all belonging to the branch of the genus Ensifer, regardless of the phylogenetic reconstruction method used (maximum likelihood, maximum-parsimony, neighbour-joining). The three groups were further characterized by API 100 auxanographic tests, host specificity and nodA gene sequence analysis. On the basis of these data, clusters A and C are suggested as representing two novel species within the genus Ensifer, for which the names Ensifer numidicus sp. nov. (type strain ORS 1407T=LMG 24690T=CIP 109850T) and Ensifer garamanticus sp. nov. (type strain ORS 1400T=LMG 24692T=CIP 109916T) are proposed. The cluster B strains were assigned to Ensifer adhaerens genomovar A.

Early effects of Sertoli cell-selective androgen receptor ablation on testicular gene expression

Evidence from several models of hormone depletion and/or replacement and from knockout animals points to a key role of androgens in the control of spermatogenesis. In testes of mice with a Sertoli cell-selective ablation of the androgen receptor (SCARKO), transcriptional profiling, using microarray technology, revealed that, already on postnatal day 10,692 genes are differentially expressed compared with testes of control mice. Further evaluation of a subset of these genes by quantitative RT-PCR suggested that differences in expression may already be evident on day 8 or earlier. As the androgen receptor in mouse Sertoli cells becomes immunologically detectable around day 5, we tried to identify the earliest responses to androgens by a new transcriptional profiling study on testes from 6-day-old SCARKO and control mice. No obvious and novel early androgen response genes, potentially acting as mediators of subsequent indirect androgen actions, could be identified. However, several genes differentially expressed on day 10 already displayed a response to androgen receptor ablation on day 6. Quantitative RT-PCR studies for 12 of these genes on 10 paired SCARKO and control testes from 4-, 6-, 8-, 10-, 20- and 50-day-old mice revealed significant differences in expression level from day 4 onwards for three genes (Eppin, PCI, Cldn11) and from day 6 onwards for one more gene (Rhox5). For at least two of these genes (Rhox5 and Eppin), there is evidence for direct regulation via the androgen receptor. For three additional genes (Gpd1, Tubb3 and Tpd52l1) significantly lower expression in the SCARKO was noted from day 8 onwards. For all the studied genes, an impressive increase in transcript levels was observed between day 4-50 and differential expression was maintained in adulthood. It is concluded that the SCARKO model indicates incipient androgen action in mouse Sertoli cells from day 4 onwards.

Loss of heterozygosity at the BRCA2 locus is a common finding in prostate cancer in men with a germline BRCA2 mutation

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Background: The prevalence of prostate cancer (PC) is higher in men with a germline mutation in BRCA2 and to a lesser extent BRCA1. It is unclear as to whether a causal relationship exists between these mutations and PC tumorigenesis. The primary aim of this pilot study was to examine for loss of heterozygosity (LOH) in PC samples from men with a known BRCA1/2 mutation. Secondary aims included assessment of the clinical and pathological features of PC in these individuals. Methods: Subjects were male carriers of a germline BRCA1/2 mutation enrolled in kConFab with a diagnosis of PC. LOH analysis was performed using multiplex ligation-dependent probe amplification and confirmed using PCR and sequencing. Clinical data was obtained on all individuals together with histopathology review. Results: In total, 134 pedigrees from BRCA1/2 mutation positive families known to include = 1men with PC were reviewed; 192 men were identified as having PC, however, only 26 were found to carry a pathogenic family specific mutation. Of these, 14 were ineligible as prostate tissue was unavailable. LOH was therefore assessed in 12 subjects (3 BRCA1 and 9 BRCA2). LOH at the BRCA2 locus was seen in 8/9 (89%) subjects with a BRCA2 mutation whilst the ninth showed no LOH. None of the samples from BRCA1 carriers were found to have LOH at the BRCA1 locus. For samples showing LOH, sequencing confirmed loss of the wild-type allele. No unique clinical or histopathological subtype was identified. Conclusions: LOH appears to occur very frequently at the BRCA2 locus in PC arising in men known to carry a germline BRCA2 mutation with LOH heavily biased towards loss of the wild-type allele. Whilst the cohort studied is small, these two results strongly indicate that BRCA2 is a tumour suppressor of PC and is the first gene shown to have this property. In contrast, failure to identify LOH in the BRCA1 samples suggests that BRCA1 is unlikely to be integral in the development of PC. These results should be confirmed in a larger cohort and further research into the mechanisms of BRCA2 induced prostate tumorigenesis is warranted.

No significant financial relationships to disclose.