30-day morbidity and mortality after transoral robotic surgery for human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma: A retrospective analysis of two prospective adjuvant de-escalation trials (MC1273 & MC1675).

OBJECTIVE: Dose de-escalation of adjuvant therapy (DART) in patients with HPV(+)OPSCC was investigated in two prospective Phase II and III clinical trials (MC1273 and MC1675). We report the 30-day morbidity and mortality associated with primary TORS resection in patients enrolled in these trials. MATERIALS AND METHODS: Patients with HPV(+)OPSCC, who underwent TORS resection between 2013 and 2020 were considered in this analysis. The severity of postoperative transoral bleeding was graded using both the Hinni Grade (HG) transoral surgery bleeding scale and the Common Terminology for Adverse Events (CTCAE) v5.0. Post-surgical complications within 30 days of surgery, as well as rates of tracheostomy, PEG and nasogastric tube placement. RESULTS: 219 patients were included. A total of 7 (3.2 %) patients had a tracheostomy placed at the time of surgery, and all were decannulated within 26 days (median: 5, range: 2-26). There were 33 (15.1 %) returns to the emergency department (ED) with 10 (4.6 %) patients requiring readmission. Using the HG scale, 10 (4.6 %) patients experienced ≥ Grade 3 bleeding with no Grade 5 or 6 bleeds. In contrast, using the CTCAE scale, 15 patients (6.8 %) experienced ≥ Grade 3 bleeding with no Grade 5 bleeds. There was one post-operative death in a patient withdrawn from the trial, and no deaths related to hemorrhage. CONCLUSION AND RELEVANCE: TORS for HPV(+)OPSCC in carefully selected patients at a high volume center was associated with low morbidity and mortality.

Measuring farmers' attitude towards breeding tools: the Livestock Breeding Attitude Scale.

Under-use of genetic improvement tools and low participation in breeding programmes are key drivers of breeding programmes under-performance. Both aspects are heavily influenced by farmers attitudes which, to date, have not been analysed in an objective and systematic manner. A key factor constraining the implementation of attitudinal studies towards livestock breeding tools is the lack of a reference scale for measuring attitudes. In this research, we provide the livestock breeding sector with such a reference measure. We developed the scale following the standardized psychometric methodologies and statistical tools. Then, as a case study, we used the scale to explore the attitudes of beef and dairy sheep farmers in Australia, New Zealand and Spain and analysed farmer and farming system factors related to those attitudes. Fourteen sheep and beef breed associations facilitated the implementation of a survey of 547 farmers, generating data that was used for the scale evaluation. The relationship between attitudinal factors and farmer and farming system factors was analysed using generalized linear models across and within breeds. The results suggest that the 8-item definitive scale we have developed is appropriate to measure farmer attitudes. We found that attitudes towards genetic improvement tools have two components; i) traditional selection and ii) genetic and genomic selection combined. This means that positive attitudes towards traditional phenotypic selection do not necessarily imply a negative attitude towards genetic and genomic selection tools. Farmer attitudes varied greatly not only across the studied breeds, species and countries, but also within them. High-educated farmers of business-oriented farms tend to have the most negative attitude towards traditional selection. However, attitudes towards genetic and genomic selection tools could not be linked to these factors. Finally, we found that the breed raised had a large effect on farmer attitude. These findings may help in the evolution of breeding programmes by identifying both the farmers most inclined to uptake breeding innovations in the early stages of its establishment and the farmers who would be more reluctant to participate in such programmes, thus informing where to focus extension efforts.

Coping with COVID-19: ventilator splitting with differential driving pressures using standard hospital equipment.

The global COVID-19 pandemic has led to a worldwide shortage of ventilators. This shortage has initiated discussions on how to support multiple patients with a single ventilator (ventilator splitting). Ventilator splitting is incompletely tested, experimental and the effects have not been fully characterised. This study investigated the effect of ventilator splitting on system variables (inspiratory pressure, flow and volume) and the possibility of different ventilation targets for each limb using only standard hospital equipment. Experiments were conducted on two test lungs with different compliances (0.02 l.cmH2 O-1 and 0.04 l.cmH2 O-1 ). The ventilator was used in both pressure and volume control modes and was set to ventilate the low compliance lungs at end-tidal volumes of 500 ± 20 ml. A flow restrictor apparatus consisting of a Hoffman clamp and tracheal tube was connected in series to the inspiratory limb of the high compliance test lungs and the resistance modified to achieve end-tidal volumes of 500 ± 20 ml. The restriction apparatus successfully modified the inspiratory pressure, minute ventilation and volume delivered to the high compliance test lungs in both pressure control (27.3-17.8 cmH2 O, 15.2-8.0 l.min-1 and 980-499 ml, respectively) and volume control (21.0-16.7 cmH2 O, 10.7-7.9 l.min-1 and 659-498 ml, respectively) ventilation modes. Ventilator splitting is not condoned by the authors. However, these experiments demonstrate the capacity to simultaneously ventilate two test lungs of different compliances, and using only standard hospital equipment, modify the delivered pressure, flow and volume in each test lung.

Assessment of the genetic and economic impact of performance recording and genotyping in Australian commercial sheep operations.

With the new opportunities from DNA technology, multitier breeding schemes have the potential to become more effective and more integrated. Integrated breeding schemes can also be better adapted to account for potential genotype by environment interactions (G × E) between tiers. In this case, phenotypic and genotype information from lower tiers becomes more valuable as it involves measurement of traits that directly represent the breeding objective. The objective of this study was to compare scenarios that represented different selection strategies and their economic effectiveness in fine-wool commercial sheep operations that exploit multitier breeding structures. Genomic selection (GS) applied in the multiplier and the commercial tier presented the largest additional revenue among all scenarios, as it resulted in the largest amount of genetic progress. The largest benefits from GS were outweighed by the genotyping costs, which made DNA parentage the most feasible strategy for the multiplier tier, resulting in the highest cumulative net present value (CNPV). The benefits of phenotypes and genotype information from the commercial environment were larger in the presence of G × E between the nucleus and the commercial tier. The CNPV was larger with a 50% reduction in genotyping costs, which increased the returns of GS scenarios by 2.7-fold on average. Higher selection intensity when selecting multiplier rams also resulted in larger benefits. In this case, returns for the breeding scheme were 3.5-fold higher when 33% of multiplier males were selected based on commercial information, compared to scenarios selecting 50% of the available multiplier rams. The benefits of collecting commercial phenotypes and genotypes were long term, which means that return on investment often took more than 10 years to be achieved, and were largely dependent on two-stage selection to reduce cost while maintaining selection efficiency and on the cost of a genotype test.

Prediction of effects of beef selection indexes on greenhouse gas emissions.

Genetic improvement in production efficiency traits can also drive reduction in greenhouse gas emissions. This study used international 'best-practice' methodology to quantify the improvements in system-wide CO2 equivalent emissions per unit of genetic progress in the Irish Maternal Replacement (MR) and Terminal (T) beef cattle indexes. Effects of each index trait on system gross emissions (GE) and system emissions intensity (EI) were modelled by estimating effects of trait changes on per-animal feed consumption and associated methane production, per-animal meat production and numbers of animals in the system. Trait responses to index selection were predicted from linear regression of individual bull estimated breeding values for each index trait on their MR or T index value, and the resulting regression coefficients were used to calculate trait-wise responses in GE and EI from index selection. Summed over all trait responses, the MR index was predicted to reduce system GE by 0.810 kg CO2e/breeding cow per year per € index and system EI by 0.009 kg CO2e/kg meat per breeding cow per year per € index. These reductions were mainly driven by improvements in cow survival, reduced mature cow maintenance feed requirements, shorter calving interval and reduced offspring mortality. The T index was predicted to reduce system EI by 0.021 kg CO2e/kg meat per breeding cow per year per € index, driven by increased meat production from improvements in carcass weight, conformation and fat. Implications for incorporating an EI reduction index to the current production indexes and long-term projections for national breeding programs are discussed.

Farmer views on calving difficulty consequences on dairy and beef farms.

Calving difficulty (CD) is a key functional trait with significant influence on herd profitability and animal welfare. Breeding plays an important role in managing CD both at farm and industry level. An alternative to the economic value approach to determine the CD penalty is to complement the economic models with the analysis of farmer perceived on-farm impacts of CD. The aim of this study was to explore dairy and beef farmer views and perceptions on the economic and non-economic on-farm consequences of CD, to ultimately inform future genetic selection tools for the beef and dairy industries in Ireland. A standardised quantitative online survey was released to all farmers with e-mail addresses on the Irish Cattle Breeding Federation database. In total, 271 farmers completed the survey (173 beef farmers and 98 dairy farmers). Both dairy and beef farmers considered CD a very important issue with economic and non-economic components. However, CD was seen as more problematic by dairy farmers, who mostly preferred to slightly reduce its incidence, than by beef farmers, who tended to support increases in calf value even though it would imply a slight increase in CD incidence. Farm size was found to be related to dairy farmer views of CD with farmers from larger farms considering CD as more problematic than farmers from smaller farms. CD breeding value was reported to be critical for selecting beef sires to mate with either beef or dairy cows, whereas when selecting dairy sires, CD had lower importance than breeding values for other traits. There was considerable variability in the importance farmers give to CD breeding values that could not be explained by the farm type or the type of sire used, which might be related to the farmer non-economic motives. Farmer perceived economic value associated with incremental increases in CD increases substantially as the CD level considered increases. This non-linear relationship cannot be reflected in a standard linear index weighting. The results of this paper provide key underpinning support to the development of non-linear index weightings for CD in Irish national indexes.

New breeding objectives and selection indices for the Australian dairy industry.

This study comprises an update of the economic values for dairy traits for the Australian industry and the formulation of updated selection indices. An economic model, which calculates partial economic values for each trait individually, was developed to determine the economic implications of selective dairy breeding, based on the effect of trait changes on the profit of commercial dairy farms in Australia. Selection indices were developed from economic values, which were transformed into base economic weights by including the discounted genetic expressions coefficients. Economic weights (in Australian dollars) were 1.79, 6.92, -0.10, -5.44, 8.84, 7.68, 1.07, 4.86, 1.91, 3.51, 4.90, 0.31, 2.03, 2.00, and 0.59, for milk fat (kg), milk protein (kg), milk volume (L), body weight (kg), survival (%), residual survival (%), somatic cell count (cells/mL), fertility (%), mammary system [Australian Breeding Value (ABV) unit], temperament (ABV unit), milking speed (ABV unit), udder depth (%), overall type (%), fore udder attachment (%), and pin set (%), respectively. The updated economic weights presented in this study constituted the basis of the definition for 3 new indices. These indices were developed from combination of bioeconomic principles, patterns of farmer preferences for trait improvements, and desired gains approaches. The 3 indices, Balanced Performance Index, Health Weighted Index, and Type Weighted Index, have been released to the industry.

An evaluation of alternative selection indexes for a non-linear profit trait approaching its economic optimum.

This study used simulation to evaluate the performance of alternative selection index configurations in the context of a breeding programme where a trait with a non-linear economic value is approaching an economic optimum. The simulation used a simple population structure that approximately mimics selection in dual purpose sheep flocks in New Zealand (NZ). In the NZ dual purpose sheep population, number of lambs born is a genetic trait that is approaching an economic optimum, while genetically correlated growth traits have linear economic values and are not approaching any optimum. The predominant view among theoretical livestock geneticists is that the optimal approach to select for nonlinear profit traits is to use a linear selection index and to update it regularly. However, there are some nonlinear index approaches that have not been evaluated. This study assessed the efficiency of the following four alternative selection index approaches in terms of genetic progress relative to each other: (i) a linear index, (ii) a linear index updated regularly, (iii) a nonlinear (quadratic) index, and (iv) a NLF index (nonlinear index below the optimum and then flat). The NLF approach does not reward or penalize animals for additional genetic merit beyond the trait optimum. It was found to be at least comparable in efficiency to the approach of regularly updating the linear index with short (15 year) and long (30 year) time frames. The relative efficiency of this approach was slightly reduced when the current average value of the nonlinear trait was close to the optimum. Finally, practical issues of industry application of indexes are considered and some potential practical benefits of efficient deployment of a NLF index in highly heterogeneous industries (breeds, flocks and production environments) such as in the NZ dual purpose sheep population are discussed.

Fast-track rapid warfarin reversal for elective surgery: extending the efficacy profile to high-risk patients with cancer.

Periprocedural management of patients on long-term warfarin therapy remains a common and important clinical issue, with little high-quality data to guide this complex process. The current accepted practice is cessation of warfarin five days preoperatively, but this is not without risk and can be complicated, particularly if bridging is required. An alternative method utilising low-dose intravenous vitamin K the day before surgery has been shown previously to be efficacious, safe and convenient in an elective surgical population receiving chronic warfarin therapy. The efficacy and utility of this 'fast-track' warfarin reversal protocol in surgical patients with cancer, who were at high risk of both thromboembolism and bleeding was investigated in a prospective, single-arm study at a dedicated cancer centre. Seventy-one patients underwent 82 episodes of fast-track warfarin reversal (3 mg intravenous vitamin K 18 to 24 hours before surgery). No patient suffered an adverse reaction to intravenous vitamin K, all but one achieved an International Normalized Ratio =1.5 on the day of surgery, and no surgery was deferred. Assays of vitamin K-dependent factor levels pre- and post-vitamin K demonstrated restoration of functional activity to within an acceptable range for surgical haemostasis. While this alternative method requires further validation in a larger prospective randomised study, we have now extended our use of fast-track warfarin reversal using vitamin K to patients with cancer, on the basis of our experience of its safety, convenience, reliability and efficacy.

A "cure" for preeclampsia: Improving neonatal outcomes by overcoming excess fetal placental vascular resistance.

From a broad perspective there are only three arterial systems that respond to relative hypoxia with vasoconstriction. They are the placental, the pulmonic and the renal vascular beds. The renal system's adaptation to hypoxia is markedly different from the other two circulatory beds and will not be further considered here. Regional vasoconstriction is adaptive in the placenta and lung because it redirects red blood cells from areas of relative hypoxia to more oxygenated areas thereby maximizing oxygen uptake for a given cardiac output. The fetal placental and pulmonary vascular systems are unique because their smooth muscle cells have a unique and possibly identical potassium channel that responds to hypoxia by closing, thereby depolarizing the cell membrane allowing calcium ion influx and muscle contraction. It may be that a variety of initial causes of temporary or local placental hypoxia initiate a cascade of first fetal placental then maternal vasoconstriction and endothelial activation leading to the clinical syndrome we call preeclampsia. The response cascades seen in preeclampsia, which for purposes of this article I will abbreviate as (PECL), after development of widespread vasoconstriction, will also be seen to be identical or at least parallel in pulmonary hypertension (PAH). This means that some or all of the pharmacotherapies presently used, tested or considered in early PAH may also have a therapeutic effect in PECL by reducing fetal placental arterial resistance thereby increasing fetal placental flow. This would allow increased oxygen and other nutrient uptake and possibly increased fetal cardiac output in the face of reduced fetal cardiac work. This may allow a delay in delivery in which fetuses grow and are better oxygenated in preterm PECL, improving neonatal outcomes.

Comparison of breeding objectives across countries with application to sheep indexes in New Zealand and Ireland.

Breeding objectives and selection indexes underpin the direction, the extent and the economic implications of selection in livestock populations under specific production systems. The objective of this study was to describe the methodology to calculate correlations between national selection indexes and gain a deeper understanding of the factors influencing responses in economically important traits in both the New Zealand and Irish sheep industries. Moderate to strong correlations were calculated among indexes within and between countries, with the strongest correlation (0.86) between the New Zealand and Irish maternal indexes. In both countries, responses to selection in the maternal indexes are largely driven by growth traits; each index, however, has a different balance of traits. Ewe mature weight also accounts for an important proportion of overall response and has significant emphasis in both maternal indexes. The majority of emphasis in terminal indexes of both countries is on growth and meat traits. Results from this study indicate that differences between national breeding objectives are unlikely to be a barrier to exchange of gene stocks among countries. Future research should investigate the extent to which genotype-by-environment (G × E) interactions exist at the level of individual traits. The methodology presented in this study is robust and represents an opportunity to inform the potential merits of international exchange of germplasm.

Analyzing the heterogeneity of farmers' preferences for improvements in dairy cow traits using farmer typologies.

Giving consideration to farmers' preferences for improvements in animal traits when designing genetic selection tools such as selection indexes might increase the uptake of these tools. The increase in use of genetic selection tools will, in turn, assist in the realization of genetic gain in breeding programs. However, the determination of farmers' preferences is not trivial because of its large heterogeneity. The aim of this study was to quantify Australian dairy farmers' preferences for cow trait improvements to inform and ultimately direct the choice of traits and selection indexes in the 2014 review of the National Breeding Objective. A specific aim was to analyze the heterogeneity of preferences for cow trait improvements by determining whether there are farmer types that can be identified with specific patterns of preferences. We analyzed whether farmer types differed in farming system, socioeconomic profile, and attitudes toward breeding and genetic evaluation tools. An online survey was developed to explore farmers' preferences for improvement in 13 cow traits. The pairwise comparisons method was used to derive a ranking of the traits for each respondent. A total of 551 farmers fully completed the survey. A principal component analysis followed by a Ward hierarchical cluster analysis was used to group farmers according to their preferences. Three types of farmers were determined: (1) production-focused farmers, who gave the highest preference of all for improvements in protein yield, lactation persistency, feed efficiency, cow live weight, and milking speed; (2) functionality-focused farmers with the highest preferences of all for improvements in mastitis, lameness, and calving difficulty; and (3) type-focused farmers with the highest preferences of all for mammary system and type. Farmer types differed in their age, their attitudes toward genetic selection, and in the selection criteria they use. Surprisingly, farmer types did not differ for herd size, calving, feeding system, or breed. These results support the idea that preferences for cow trait improvements are intrinsic to farmers and not to production systems or breeds. As a result of this study, and some bioeconomic modeling (not included in this study), the Australian dairy industry has implemented a main index and 2 alternative indexes targeting the different farmer types described here.

Development of an index to rank dairy females on expected lifetime profit.

The objective of this study was to develop an index to rank dairy females on expected profit for the remainder of their lifetime, taking cognizance of both additive and nonadditive genetic merit, permanent environmental effects, and current states of the animal including the most recent calving date and cow parity. The cow own worth (COW) index is intended to be used for culling the expected least profitable females in a herd, as well as inform purchase and pricing decisions for trading of females. The framework of the COW index consisted of the profit accruing from (1) the current lactation, (2) future lactations, and (3) net replacement cost differential. The COW index was generated from estimated performance values (sum of additive genetic merit, nonadditive genetic merit, and permanent environmental effects) of traits, their respective net margin values, and transition probability matrices for month of calving, survival, and somatic cell count; the transition matrices were to account for predicted change in a cow's state in the future. Transition matrices were generated from 3,156,109 lactation records from the Irish national database between the years 2010 and 2013. Phenotypic performance records for 162,981 cows in the year 2012 were used to validate the COW index. Genetic and permanent environmental effects (where applicable) were available for these cows from the 2011 national genetic evaluations and used to calculate the COW index and their national breeding index values (includes only additive genetic effects). Cows were stratified per quartile within herd, based on their COW index value and national breeding index value. The correlation between individual animal COW index value and national breeding index value was 0.65. Month of calving of the cow in her current lactation explained 18% of the variation in the COW index, with the parity of the cow explaining an additional 3 percentage units of the variance in the COW index. Females ranking higher on the COW index yielded more milk and milk solids and calved earlier in the calving season than their lower ranking contemporaries. The difference in phenotypic performance between the best and worst quartiles was larger for cows ranked on COW index than cows ranked on the national breeding index. The COW index is useful to rank females before culling or purchasing decisions on expected profit and is complementary to the national breeding index, which identifies the most suitable females for breeding replacements.

A preference-based approach to deriving breeding objectives: applied to sheep breeding.

Using internet-based software known as 1000Minds, choice-experiment surveys were administered to experts and farmers from the Irish sheep industry to capture their preferences with respect to the relative importance - represented by part-worth utilities - of target traits in the definition of a breeding objective for sheep in Ireland. Sheep production in Ireland can be broadly separated into lowland and hill farming systems; therefore, each expert was asked to answer the survey first as if he or she were a lowland farmer and second as a hill farmer. In addition to the experts, a group of lowland and a group of hill farmers were surveyed to assess whether, and to what extent, the groups' preferences differ from the experts' preferences. The part-worth utilities obtained from the surveys were converted into relative economic value terms per unit change in each trait. These measures - referred to as 'preference economic values' (pEVs) - were compared with economic values for the traits obtained from bio-economic models. The traits 'value per lamb at the meat processor' and 'lamb survival to slaughter' were revealed as being the two most important traits for the surveyed experts responding as lowland and hill farmers, respectively. In contrast, 'number of foot baths per year for ewes' and 'number of anthelmintic treatments per year for ewes' were the two least important traits. With the exception of 'carcase fat class' (P < 0.05), there were no statistically significant differences in the mean pEVs obtained from the surveyed experts under both the lowland and hill farming scenarios. Compared with the economic values obtained from bio-economic models, the pEVs for 'lambing difficulty' when the experts responded as lowland farmers were higher (P < 0.001); and they were lower (P < 0.001) for 'carcase conformation class', 'carcase fat class' (less negative) and 'ewe mature weight' (less negative) under both scenarios. Compared with surveyed experts, pEVs from lowland farmers differed significantly for 'lambing difficulty', 'lamb survival to slaughter', 'average days to slaughter of lambs', 'number of foot baths per year for ewes', 'number of anthelmintic treatments per year for ewes' and 'ewe mature weight'. Compared with surveyed experts, pEVs from hill farmers differed significantly for 'lambing difficulty', 'average days to slaughter of lambs' and 'number of foot baths per year for ewes'. This study indicates that preference-based tools have the potential to contribute to the definition of breeding objectives where production and price data are not available.

All at-risk patients are not created equal: analysis of Braden pressure ulcer risk scores to identify specific risks.

PURPOSE: To improve identification of risk factors for pressure ulcer development and enhance targeted interventions and prevention strategies. SUBJECTS AND SETTING: The records of 12,566 adult patients hospitalized in intensive or progressive care units within Mayo Clinic were analyzed. Inclusion criteria were Braden Scale of 18 or less during the hospitalization; exclusion criteria were preexisting pressure ulcer or length of stay less than 24 hours. METHODS: This study is a retrospective cohort analysis of electronic medical record data from January 1, 2007, to December 31, 2007. Only iatrogenic stage 2 to 4 pressure ulcers were considered as incident events. Demographic and clinical data were extracted from the medical record, including total Braden Scale score and Braden subscale scores at hospital admission, length of stay, admission to the intensive care unit at the time of hospitalization, and presence of acute respiratory failure, acute renal failure, or diabetes. Time to event was calculated based on time from admission to pressure ulcer occurrence or to hospital discharge. RESULTS: Four hundred sixteen (3.3%) of patients developed a pressure ulcer during their hospitalizations. The Braden Scale score total by itself was found to be highly predictive of pressure ulcer development (P ≤ .0001, C = 0.71), as were all individual subscores. The friction/shear subscale had the greatest predictive power among Braden Scale scores (subscores and total score) (C = 0.83). The multivariate model after selection included 5 Braden Scale subscales, surgery, and acute respiratory failure (C = 0.91). CONCLUSIONS: The total Braden Scale score is predictive of pressure ulcer development but does not assist the clinician to develop an individualized targeted prevention plan. In contrast, the use of subscale scores can enhance prevention programs and resource utilization by focusing care on the risk factors specific to the individual patient.

Isolated visceral angioedema: an underdiagnosed complication of ACE inhibitors?

Angiotensin-converting enzyme (ACE) inhibitors are known to cause potentially fatal peripheral angioedema in some patients. ACE inhibitors may also cause isolated visceral angioedema, a rarely reported complication. This article describes 2 patients who experienced this complication. Both patients came to medical attention with episodes of recurrent abdominal symptoms that had occurred while taking ACE inhibitors for hypertension. Each patient had undergone surgical procedures for symptoms that persisted after surgery and were ultimately relieved with cessation of their ACE inhibitors. These cases call attention to what may be an underappreciated cause of abdominal pain in patients presenting to emergency departments.

A rapid immunoassay predicts BRCA1 and BRCA2 mutations in buccal cells.

We developed a rapid, non-invasive, and inexpensive, assay capable of identifying BRCA1 and BRCA2 (BRCA) mutations in buccal cells. To determine the predictive value of this immunoassay, a double blind study of 13 high risk individuals was conducted by two independent teams. As greater than 90% of BRCA mutations result in protein truncations, a diminished anti-carboxy immunoreactivity relative to anti-amino immunoreactivity was scored as predictive for mutation. Comparison to BRCA DNA analysis was undertaken. The positive and negative predictive values were 90% and 100% respectively (p<0.02), suggesting great promise as an inexpensive and rapid screen for BRCA mutations.

Immunohistochemical analysis of BRCA2 expression in normal human buccal cells.

Previously we demonstrated that protein coded by the BRCA1 gene was expressed in normal human buccal cells. The present study confirmed that BRCA2 protein was similarly expressed in these cells. Messenger RNA for BRCA2 was detected with sequential use of two primer sets. Pooled cell samples from healthy donors reacted strongly with two commercially available antibodies, I17 and C15. Immunoreactivity was present in both cytoplasmic and nuclear compartments. We conclude buccal cells will provide a suitable model for exploration of normal BRCA function.

An antibody assay predictive of BRCA1 mutations in ovarian tumors and normal tissue.

To determine whether immunohistochemistry can identify BRCA1 mutations, immunohistochemical (IH) analysis was undertaken on paraffin sections of paired ovarian cancer and normal tissue using antibodies against both terminal regions of the BRCA1 protein. Ten patients at risk for BRCA1 mutations were studied. The results of BRCA1 mutation analysis and IH were compared. In tumor, IH correctly identified the presence or absence of loss of heterozygosity in all specimens. In all uninvolved specimens, IH correctly identified the presence or absence of a germline mutation. The sensitivity, specificity, positive and negative predictive values were 100% suggesting promise as a rapid and inexpensive screen.