A structured community engagement strategy to support uptake of TB active case-finding.

BACKGROUND: In Lima, Peru, a mobile TB screening program ("TB Móvil") was implemented in high TB prevalence districts to increase TB screening. Community engagement activities to promote TB Móvil were simultaneously conducted. OBJECTIVE: To describe a structured, theory-driven community engagement strategy to support the uptake of TB Móvil. METHODS: We adapted Popular Opinion Leader (POL), an evidence-based social networking intervention previously used in Peru to promote HIV testing, for TB Móvil. Community health workers, women who run soup kitchens, and motorcycle taxi drivers served as "popular opinion leaders" who disseminated information about TB Móvil in everyday conversations, aided by a multi-media campaign. Performance indicators of POL included the number/characteristics of persons screened; number of multimedia elements; and proportion of persons with abnormal radiographs hearing about TB Móvil before attending. RESULTS: Between February 2019 and January 2020, 63,899 people attended the TB Móvil program at 210 sites; 60.1% were female. The multimedia campaign included 36 videos, 16 audio vignettes, flyers, posters, community murals and "jingles." Among attendees receiving an abnormal chest X-ray suggestive of TB, 48% (6,935/14,563) reported hearing about TB Móvil before attending. CONCLUSIONS: POL promotes the uptake of TB Móvil and should be considered as a strategy for increasing TB screening uptake.

CONTEXTE: À Lima, Pérou, un programme mobile de dépistage de la TB (« TB Móvil ¼) a été mis en place dans les quartiers à forte prévalence de TB afin d'accroître le dépistage de la maladie. Des activités de mobilisation communautaire visant à promouvoir TB Móvil ont été menées en parallèle. L'objectif de ce rapport est de décrire une stratégie structurée de mobilisation communautaire, fondée sur des principes théoriques, afin de soutenir le recours au programme TB Móvil. MÉTHODES: Nous avons adapté à TB Móvil l'intervention factuelle de réseautage social appelée « Popular Opinion Leader (POL; leader d'opinion) ¼, précédemment utilisée au Pérou pour promouvoir le dépistage du VIH. Les agents de santé communautaires, les femmes responsables de la soupe populaire et les chauffeurs de mototaxis étaient des leaders d'opinion. Ils communiquaient des informations sur TB Móvil lors de leurs conversations quotidiennes, qui étaient étayées par une campagne multimédia. Les indicateurs de performance des POL comprenaient le nombre/les caractéristiques des personnes dépistées, le nombre d'éléments multimédias et le pourcentage de personnes avec cliché radiographique anormal qui avaient entendu parler de TB Móvil avant de se faire dépister. RÉSULTATS: Entre février 2019 et janvier 2020, 63 899 personnes ont pris part au programme TB Móvil dans 210 sites ; 60,1% étaient des femmes. La campagne multimédia reposait sur 36 vidéos, 16 vignettes audio, des prospectus, des posters, des peintures murales dans la communauté et des « jingles ¼. Parmi les personnes dont la radiographie pulmonaire était anormale et évocatrice de TB, 48% (6 935/14 563) ont rapporté avoir entendu parler de TB Móvil avant de venir consulter. CONCLUSIONS: L'intervention POL, qui semblait renforcer le recours au programme TB Móvil, peut donc servir d'une stratégie de promotion du dépistage de la TB.

Early outcomes after definitive chemoradiation therapy with Vienna/Venezia hybrid high-dose rate brachytherapy applicators for cervical cancer: A single-institution experience.

PURPOSE: The Vienna and Venezia (Elekta) are hybrid intracavitary/interstitial brachytherapy (BT) applicators for cervical cancers unsuitable for intracavitary BT alone to improve target coverage or reduce critical organ dose. There is limited outcome data with the use of these applicators outside published experience of the EMBRACE group. We report feasibility and early outcomes with the use of these hybrid applicators at our institution. METHODS AND MATERIALS: Hybrid applicators were used to treat 61 patients with cervical cancer from November 2011 to December 2019. Indications for hybrid applicator use were involvement of the vagina in 10 patients (16%), residual central or parametrial disease in 46 patients (75%), and a narrow introitus in 5 patients (9%). Toxicities were graded using the CTCAE v4.0. Outcomes were assessed with the Kaplan-Meier method. RESULTS: Median follow-up was 16 months (IQR 9-32 mos). Median HRCTV volume was 31.6 cm3 (IQR 25-48 cm3). Median HRCTV D90 was 86.1 Gy (IQR 84.3-88.0 Gy). In 54 patients with follow-up PET/CT at 3 months, complete initial imaging response locally was seen in 46 patients.Estimated 12-month Kaplan-Meier overall survival, locoregional control, distant control, and recurrence-free survival estimates were 86.9%, 80.6%, 73.8%, and 65.9%, respectively. The 12-month incidence of Grade 3+ GI/GU chronic toxicities was 5.7%, consisting of vesicovaginal fistula, rectovaginal fistula, and ureterovesical fistula. CONCLUSIONS: Our single-institution data support the use of the hybrid applicators, as an alternative to traditional BT applicators when clinically warranted. Use of hybrid applicators is feasible with adequate coverage of disease in the vagina and parametrium.

Regional Control and Chemoradiotherapy Dose Response for Clinically Involved Lymph Nodes in Patients with Locally Advanced Endometrial Cancers Who are Not Candidates for Upfront Surgical Staging Extrafascial Hysterectomy.

AIMS: There are limited data in endometrial cancer for nodal control and appropriate treatment volume for non-surgically resected nodes treated with chemoradiotherapy (CRT) for patients who are not candidates for upfront extrafascial hysterectomy. MATERIALS AND METHODS: Patients (n = 105) with clinical stage ≥ II endometrial cancer who were not candidates for upfront extrafascial hysterectomy treated with preoperative CRT were retrospectively reviewed. CRT included pelvic nodes to the common iliac for node-negative disease and para-aortic nodes to the renal vessel for any node-positive disease. Involved nodes most commonly received a boost of 55 Gy in 25 fractions ± additional 4-6 Gy sequential boost for nodes >2 cm. RESULTS: Of the included 95 patients, 55 patients were node positive, with a total of 300 positive nodes. At a median follow-up of 25 months (interquartile range 9-46), the 3-year regional control was 91%. The 3-year involved nodal control rate was 96%. Involved nodal control was significantly higher in type I histology, nodes <2 cm and by radiation dose (75% for <55 Gy, 98% for 55 Gy in 25 fractions and 89% for >55 Gy, P = 0.03). The 3-year para-aortic failure rate for node negative patients treated with pelvis-only CRT was significantly higher with positron emission tomography/computed tomography (PET/CT) versus computed tomography (CT)-based staging (0% versus 20%). CONCLUSION: This is the largest study examining regional control rates of involved lymph nodes with CRT for patients who were not candidates for upfront extrafascial hysterectomy. Nodal failure was low following CRT and dose ≥55 Gy in 25 fractions seems to be adequate for involved nodes.

Is the risk of substantial LVSI in stage I endometrial cancer similar to PORTEC in the North American population? - A single-institution study.

OBJECTIVES: A pooled analysis of PORTEC-1 & 2 identified substantial lymphovascular space invasion (LVSI) in 4.8% of patients, which predicted for pelvic recurrence, distant metastasis, and overall survival. Our institution implemented the PORTEC three-tier system of LVSI reporting (absent, focal, or substantial). We aimed to quantify the incidence of substantial LVSI in a North American population and to correlate extent of LVSI with lymph node (LN) involvement. METHODS: A retrospective review was conducted on patients with clinically uterine-confined, endometrioid type endometrial cancer who underwent surgical staging and were found to have pT1a-b disease. Binary logistic regression was used to assess predictors of LN involvement (defined as ITC, micrometastases, or macrometastases). RESULTS: In total, 438 patients with pT1a-b disease were identified. In the overall cohort and in the subset meeting PORTEC-1 inclusion criteria (n = 195), no LVSI was present in 67.4% and 50.8%; focal LVSI was present in 16.7% and 24.1%; and substantial LVSI was present in 16.0% and 25.1%, respectively. Among patients who underwent surgical LN assessment (79.2%, n = 347), LNs were involved in 3.3% without LVSI, 7.5% with focal LVSI (OR 2.4), and 15.2% with substantial LVSI (OR 5.3) (p = .005), with a similar trend in the PORTEC-1 cohort. Extent of LVSI correlated with disease burden in LN metastases. CONCLUSION: Our incidence of substantial LVSI was three to five times higher than reported by PORTEC and correlated with LN involvement. This questions the reproducibility of the three-tier LVSI reporting system and emphasizes the need for multi-institutional data outside PORTEC for confirmation of our findings.

Barriers and facilitators to early access of bedaquiline and delamanid for MDR-TB: a mixed-methods study.

SETTING: Phase II trials for bedaquiline (BDQ) and delamanid (DLM) were completed by 2011 and the drugs were approved by stringent regulatory authorities for the treatment of multidrug-resistant tuberculosis (MDR-TB) between 2012 and 2014. Manufacturers established 'early access' mechanisms to provide drugs before local registration. OBJECTIVE: To inform improvements in early access, we explored experiences of providers and advocates in accessing BDQ and DLM before the end of 2015 using a mixed-methods design. DESIGN: We examined barriers and facilitators to early access through an electronic survey. Barriers and facilitators were classified as occurring at the manufacturer- or country-level. We identified themes using inductive content analysis and illustrated themes through case studies. RESULTS: We analysed 41 survey responses from 36 respondents reporting on 22 countries; early access was attempted in 30 (73%) survey responses. Eligibility restrictions (11/30, 37%) and complicated and slow processes (8/30, 27%) were manufacturer-level barriers; access to companion drugs (10, 33%) and importation difficulties (4, 13%) were country-level barriers. Previous experience with manufacturer (3/30, 10%) and country processes (2/30, 7%) facilitated access. Eight case studies show the human impact of barriers and facilitators. CONCLUSION: Manufacturers and countries should develop transparent processes to permit early access, particularly for diseases that largely affect the poor, such as MDR-TB. Developers should plan for this need and rapidly register drugs with proven benefit, prioritizing high-burden settings.

Process measure of FAST tuberculosis infection control demonstrates delay in likely effective treatment.

SETTING: The tuberculous infection control strategy, FAST (Find cases Actively, Separate safely and Treat effectively), recommends prompt initiation of likely effective anti-tuberculosis treatment informed by Xpert® MTB/RIF results.OBJECTIVE: To describe FAST implementation at Quang Nam Provincial TB and Lung Disease Hospital (QNH), Tam Ky, Viet Nam, using time to initiation of effective TB treatment as a process measure. DESIGN: Hospital logs were used to calculate the time to likely effective treatment in patients with pulmonary TB (PTB) hospitalised during the study period. RESULTS: Between 1 January and 31 December 2016, of 858 patients treated for PTB, 493 (57.5%) received likely effective treatment. The median time to likely effective treatment was 3 days (interquartile range 2.0-6.0), with 213 (43.2%) patients receiving likely effective treatment within 2 days. Of 81 patients receiving likely effective treatment for drug-susceptible TB with a positive Xpert result as their initial in-patient diagnostic test, 64 (79.0%) received likely effective treatment within 2 days compared with 10 (5.7%) who were initially smear-negative then found to be Xpert-positive (P < 0.0001). CONCLUSIONS: A 'time to' process measure of the FAST tuberculous infection control strategy indicates delays in the initiation of likely effective anti-tuberculosis treatment in a resource-limited hospital. Expanding access to Xpert may speed time to likely effective treatment.

Human papillomavirus infection mediates response and outcome of vulvar squamous cell carcinomas treated with radiation therapy.

PURPOSE: Human papillomavirus (HPV) is implicated as a causative factor in vulvar squamous cell carcinoma (VSCC). This study evaluates if p16-positivity, a surrogate for HPV, predicts for better response rates to chemoradiation therapy and survival. MATERIALS AND METHODS: We conducted a retrospective chart review of women treated with neoadjuvant or definitive chemoradiation (CRT) therapy from 2000 to 2016 for VSCC. p16 stain-positivity was defined as diffuse strong "block" immunoreactivity within invasive tumor. RESULTS: Seventy-three women with median follow-up of 13.4 months were analyzed. Thirty-three (45.2%) had p16+ tumors. Median age was 73 years (range: 37-89); with p16+ tumors, the median age was 60 years vs 73 years for women with p16- tumors (p < 0.001). The distribution of tumor size and stage by p16-status were similar. The complete clinical response (cCR) rate for p16+ tumors was 63.6% vs 35.0% for p16- tumors (p = 0.014). The pathologic complete response (pCR) rate for women treated neoadjuvantly was 53.8% vs 31.4% for p16+ vs p16-, respectively (p = 0.067). The combined complete response (cCR orpCR [CCR]) rate was 63.6% for p16+ and 30.0% for p16- (p = 0.004). Two-year vulvar control (VC) for women with p16+ tumors was 75.5% vs. 49.5% for p16- (p = 0.008). In women with p16+ tumors who achieved CCR, 2-year VC was 92.3% vs 52.1% for CIR (p = 0.009). For p16- tumors, 2-year VC was 67.3% vs 41.1% for CCR and CIR (p = 0.072). No woman with a p16+ tumor developed distant metastases vs. 7 with p16- tumor (p = 0.013). OS was not statistically different between p16+ cohorts, but was improved for p16- patients with CR vs CIR, 72.9% vs 18.8% (p = 0.026). CONCLUSIONS: p16-positive tumors appear to have better clinical and pathologic response rates and clinical outcomes.

Development of a fibrinolysis assay for canine plasma.

Unbalanced coagulation and fibrinolysis leads to hemorrhage or thrombosis. Thromboelastography has been used to characterize hypo- and hyper-fibrinolysis in dogs, however the technique requires specialized instrumentation and proprietary reagents that limit its availability. The aim of this study was to develop a simple microplate method for assessment of fibrinolysis in canine plasma. Plasma from healthy dogs was mixed in a microwell plate with tissue factor, calcium, phospholipid and tissue plasminogen activator. Light absorbance was measured at regular intervals until return to baseline. Peak optical density (milli-absorption units, mAU), formation velocity (mAU/s), lysis velocity (mAU/s) and area under the curve (mAU.s) were calculated. The influence of potential interferents, variation in fibrinogen and ex vivo addition of heparin and aminocaproic acid on assay performance was determined. Inter-day coefficients of variation were ≤15% for all variables. Bilirubin≤1.88mg/dL and hemoglobin≤0.09mg/dL did not interfere with assay variables. Aminocaproic acid (40µg/mL) and heparin (0.125U/mL) caused almost complete inhibition of fibrinolysis and coagulation, respectively. All variables except lysis velocity (R2=0.08) were associated with fibrinogen concentration (R2>0.8). This assay showed acceptable performance characteristics for measurement of fibrinolysis in normal canine plasma. The assay utilizes small volume citrate plasma samples and readily available instrumentation and reagents, is not influenced by mild to moderate hemolysis or icterus and detects the presence of fibrinolysis inhibitors.

A TMEM16F point mutation causes an absence of canine platelet TMEM16F and ineffective activation and death-induced phospholipid scrambling.

BACKGROUND: TMEM16F is an ion channel and calcium-dependent lipid scramblase that mediates phosphatidylserine (PS) exposure on the plasma membrane. Two disparate disease phenotypes are associated with TMEM16F loss-of-function mutations: a rare bleeding disorder (Scott syndrome) and skeletal malformations due to aberrant bone mineralization in a TMEM16F knockout mouse. We therefore undertook comparative studies of TMEM16F expression in canine Scott syndrome (CSS), an autosomal recessive platelet defect. OBJECTIVES: To define anoctamin proteins and scramblase response of CSS platelets and to determine whether TMEM16F is the CSS disease gene. METHODS: CSS TMEM16F cDNA and gene were sequenced and mutation detection was performed in CSS pedigrees. Platelet fractions from CSS dogs were isolated for proteomic and immunologic characterization of TMEM16F. Annexin V was used as a flow cytometric marker of induced platelet PS externalization. RESULTS: A TMEM16F splice site mutation segregated with the CSS trait and TMEM16F protein was undetectable in CSS platelet membranes; however, a second anoctamin, TMEM16K, was found. Proteomic analyses revealed a network of 32 proteins that differentially cosegregated with platelet plasma membrane TMEM16F. CSS platelets had profoundly impaired scramblase response to pharmacologic and physiologic agents that increase intraplatelet calcium and conditions that induce apoptotic and necrotic cell death. CONCLUSIONS: CSS platelets represent a TMEM16F-null mutant model that demonstrates a central role for TMEM16F in mediating platelet PS externalization in response to activating and death signals. Platelet TMEM16F may prove a novel drug target for modulating platelet procoagulant activity and extending platelet life span.

Coagulation factor and hemostatic protein content of canine plasma after storage of whole blood at ambient temperature.

BACKGROUND: Standard practice in canine blood banking is to produce fresh frozen plasma (FFP) by separating and freezing plasma produced from blood within 8 hours of collection. Within canine blood donation programs, this can limit the number of units collected. HYPOTHESIS/OBJECTIVES: The aim was to compare the coagulation factor and hemostatic protein content (CF&HPC) of plasma produced from blood stored at ambient temperature for 8, 12, and 24 hours. Another aim was to compare the CF&HPC between Greyhound types and other breeds. ANIMALS: None. METHODS: In vitro study. A convenience sample of 58 units of canine blood from a blood donor pool was processed to prepare and freeze plasma 8, 12, or 24 hours following collection. RESULTS: Regardless of time of processing, the units contained therapeutic CF&HPC. Frozen plasma prepared after 24 hours had significantly higher factor VIII (P = .014) and factor X (P = .03) when compared with the frozen plasma prepared at 8 hours. Factor X (P < .01), fibrinogen (P < .01), and vWF (P = .04) were significantly lower in plasma collected from Greyhound types than in plasma collected from other breeds. CONCLUSIONS AND CLINICAL IMPORTANCE: Storing whole blood for up to 24 hours is a suitable method for producing FFP. Lower values for some coagulation factors and hemostatic proteins in plasma produced from Greyhound types would not preclude these dogs as FFP donors.

Clinical characterization of canine platelet procoagulant deficiency (Scott syndrome).

BACKGROUND: Platelet function defects are rare causes of bleeding diatheses; however, disease prevalence might be underestimated because diagnosis requires assessment of specific parameters of platelet activation. OBJECTIVES: The goal of this study was to characterize the clinical presentation of canine Scott syndrome (CSS), an intrinsic platelet function defect first identified in a closed colony of German Shepherds (GSD). ANIMALS: Eleven (n = 6 female) client-owned GSD affected with CSS that sought veterinary care for one or more episodes of abnormal bleeding. METHODS: Retrospective review of all cases of CSS diagnosed through the Comparative Coagulation Laboratory at Cornell University between 2005 and 2011. The diagnosis of CSS was based on 2 measures of platelet procoagulant activity: serum prothrombin consumption and flow cytometric detection of platelet phosphatidylserine externalization after in vitro activation. RESULTS: Postoperative hemorrhage was the most common sign of CSS, whereas petechiae were not found in any dog. Although most GSD responded to platelet transfusion, refractory epistaxis in 2 GSD was managed by nasal arterial embolization. The CSS trait was not restricted to a single pedigree of related GSD or to a single geographic region. CONCLUSIONS AND CLINICAL IMPORTANCE: Unlike thrombocytopenia and platelet aggregation defects, petechiae and other capillary hemorrhage are not typical features of CSS. After preliminary screening to rule out more common causes of hemorrhage, CSS should be considered in the differential diagnosis of recurrent hemorrhage in GSD, and potentially other breeds of dog. Definitive diagnosis of CSS requires specific tests of platelet procoagulant activity.

WAG-F8(m1Ycb) rats harboring a factor VIII gene mutation provide a new animal model for hemophilia A.

BACKGROUND: We recently described an inherited coagulopathy arising in an inbred colony of WAG/RijYcb rats. The bleeding phenotype, demonstrated by both male and female rats, included periarticular hemorrhage, spontaneous bruising, prolonged bleeding from minor wounds and maternal peripartum deaths. Coagulation testing of affected rats revealed normal prothrombin time but prolongation of activated partial thromboplastin time to twice that of controls. OBJECTIVE: To determine the specific coagulation factor and the underlying genetic defect responsible for the inherited coagulopathy in the WAG/RijYcb rats. RESULTS: Evaluation of individual clotting factor activities revealed that the affected animals had a specific deficiency of factor (F) VIII (FVIII). The FVIII gene (F8) has an autosomal location on chromosome 18 in rats, in contrast to its location on the X chromosome in mice and humans. Sequencing of F8 cDNA led to the identification of a point mutation resulting in a substitution, Leu176Pro, in the A1 domain, that is predicted to disrupt the tertiary structure of the FVIII molecule. Administration of human plasma or human recombinant FVIII corrects the coagulation abnormality in the affected animals. CONCLUSIONS: We have now identified the genetic basis of the hemostatic defect in the WAG/RijYcb rat colony. The larger size of rats relative to mice and the presence of this coagulation defect in both sexes provide a unique model, well-suited to the development of novel therapies for acquired and hereditary FVIII deficiencies.

Incidence of transfusion reactions and retention of procoagulant and anticoagulant factor activities in equine plasma.

BACKGROUND: The extent of preservation of clotting factors and incidence of transfusion reactions to noncommercial equine plasma is not documented. HYPOTHESIS: Equine frozen plasma would retain its coagulation factor activity within the reference range and the incidence of transfusion reactions would be low. ANIMALS: Ten plasma donor horses. Fifty clinically ill hospitalized horses receiving plasma were reviewed to determine the incidence of reactions. METHODS: In vitro study and retrospective case review. Plasma was prepared by gravity sedimentation from whole blood refrigerated for 48 hours. The activities of factors VII through XII, antithrombin (AT), and Protein C were measured. Factor activities were compared for plasma samples obtained before blood collection (S0), after 48 hours of gravity sedimentation at 5 degrees C and after plasma separation (S1), and after 90 days of storage at -20 degrees C (S90). The medical records of 50 consecutive clinically ill horses receiving frozen plasma were reviewed to determine the incidence of transfusion reactions. RESULTS: The combined effect of plasma harvest, gravity sedimentation, decantation, and freezing caused significant reductions in factors IX, (43%P= .0013), X, (33%P= .0001), XI, (48%P= .0008), AT, (10%P= .02), and Protein C (26%P= .0001). Activities for all factors analyzed, except factor X, remained within the reference ranges. Transfusion reactions were recorded for 5/50 horses. CONCLUSIONS AND CLINICAL RELEVANCE: Clotting factors, AT, and Protein C were well preserved. The incidence of reactions to frozen plasma was 10%.

Postoperative bleeding in retired racing greyhounds.

BACKGROUND: Some retired racing Greyhounds (RRG) that undergo surgery bleed excessively. HYPOTHESIS: Greyhounds that bleed excessively will have one or more preoperative hemostatic abnormalities that can be used to predict the risk and severity of postoperative bleeding. ANIMALS: Eighty-eight RRG undergoing ovariohysterectomy or castration. METHODS: All dogs were evaluated preoperatively with a physical exam, CBC, platelet count, OSPT, APTT, platelet function with PFA-100(a); fibrinogen, d-dimer, plasminogen (Plmg), antiplasmin (AP), antithrombin (AT), and vWF concentration (vWF:Ag); vWF collagen binding assay (vWF:CBA), and Factor XIII assay. Assays were repeated in the dogs that bled, and in an age- and sex-matched control group of RRG. RESULTS: Twenty-six percent of the dogs had bleeding 36-48 hours after surgery. AP (P <.0001) and AT concentration (P= .007) were significantly lower, and vWF:CBA (P= .0284) was higher preoperatively in the dogs with excessive hemorrhage. A lower platelet count (P= .001) and hematocrit (P= .002), shorter OSPT (P= .0002) and higher plasma fibrinogen (P <.0001), and AP (P= .001) concentration were detected at the time of bleeding compared with preoperative values in the dogs that bleed excessively. The same findings were observed postoperatively for the control group, except for the decrease in hematocrit. CONCLUSIONS AND CLINICAL IMPORTANCE: The results indicate that this excessive postoperative bleeding is not attributable to a primary or secondary hemostatic defect, but could result from altered fibrinolysis.

Indirect carrier detection of canine haemophilia A using factor VIII microsatellite markers.

A panel of factor VIII microsatellite markers was developed for indirect carrier detection of canine haemophilia A (factor VIII deficiency). A total of 78 dogs, representing 14 different breed variants of haemophilia A, were genotyped at six intragenic factor VIII marker loci. The markers spanned approximately 110 kb and were located in the 5' UTR of the factor VIII (F8) gene and within introns 6, 10, 12, 14 and 21. The observed heterozygosity (n = 39 females) for these markers was 0.675, 0.82, 0.868, 0.692, 0.473 and 0.775 respectively. The affected males of each breed variant had unique marker haplotypes. In addition, the marker haplotypes varied for two unrelated haemophilic Jack Russell terriers, compatible with independent mutation events causing haemophilia in different breeds and different families. A three-marker panel (markers within introns 6, 10 and 21) was informative for 37 of the 39 females. The haemophilia-associated haplotype was defined for six breed variants based on the genotypes of an affected male and a clear male sibling, with successful carrier detection of female siblings in each pedigree. Our results demonstrate an apparent allelic heterogeneity in canine haemophilia A; however, an indirect method based on a three-marker panel is feasible to facilitate carrier detection and genetic counselling.

Evaluation of platelet aggregation using a point-of-care instrument in retired racing Greyhounds.

Veterinarians involved in Greyhound rescue have anecdotally observed that 10-15% of Greyhounds bleed profusely after simple surgical procedures. In most patients, platelet counts and hemostasis profiles are normal; therefore, it is possible that these dogs have platelet dysfunction. The PFA-100 is a novel point-of-care platelet function analyzer that has recently been evaluated as a rapid method to assess platelet function in dogs. The objectives of this study were to characterize platelet function in a group of healthy Greyhounds by means of the PFA-100. Blood samples were collected from the jugular vein from 30 healthy Greyhounds. CBC, biochemical profile, PFA-100 assay with collagen/epinephrine (COL-EPI) and collagen/ adenosindiphosphate (COL-ADP), plasma von Willebrand factor antigen concentration (vWF:Ag), and vWF collagen-binding assay (vWF:CBA) were performed. PFA-100 closure times (CTs) with COL/ADP ranged from 63 to 92 seconds (mean +/- SD, 74.7 +/- 7.9 seconds) and with COL/EPI from 87 to 238 seconds (138 +/- 41 seconds); vWF: Ag ranged from 22 to 120% (87.52 +/- 25.5%) and vWF: CBA ranged from 36 to 102% (77.4 +/- 17.3%); and platelet counts ranged from 147 to 265 x 10(9)/L (194.6 +/- 31.64 x 10(9)/L). Greyhound CTs were significantly shorter than CTs in a mixed population of 50 healthy non-Greyhound dogs, in which the COL/ADP CTs ranged from 61 to 172 seconds (mean +/- SD, 87 +/- 21.6 seconds), and the COL/ EPI CTs ranged from 81 to 300 seconds (mean +/- SD, 183 +/- 67.6 seconds; P = 0.005 for COL/ADP CT; P = 0.001 for COL/ EPI CT). Also, platelet counts were significantly lower (P = 0.001) and packed cell volume was significantly higher (P = 0.001) in the Greyhound than in the non-Greyhound group. The PFA-100 is a reproducible method that can be used in the clinical setting to assess platelet function in Greyhounds; however, normal CTs in healthy Greyhounds are shorter than in other breeds. The results obtained in this study will be used to screen for abnormal platelet function in Greyhounds with postoperative bleeding.

Heritability of plasma von Willebrand factor antigen concentration in German Wirehaired pointers.

We applied quantitative genetic analyses to a population of German Wirehaired pointer dogs affected with type 2 von Willebrand disease. Plasma von Willebrand factor (vWF) protein concentration measured as vWF antigen (vWF:Ag), clinical history, and pedigree data were compiled for 331 dogs over a 5-year test period. Eight dogs had histories of abnormal bleeding and had markedly decreased plasma vWF:Ag concentrations (<1%). Four per cent of the dogs were inbred, with an average inbreeding of 2.52%. The estimated heritability of plasma vWF concentration was 0.52. We found a major gene effect on vWF concentration. Using a single gene locus model and two different prediction methods, the upper threshold value for the aa genotype was less than 1% vWF:Ag, and the optimal threshold value for discrimination between the AA and Aa genotypes was between 68% and 72% vWF:Ag. Our analyses indicate that phenotype, assigned on the basis of a single vWF:Ag determination, is heritable and can be applied for selective breeding in a von Willebrand disease test programme.