Anaesthetic records: an evaluation of variation across England.

We collected blank non-specialist anaesthetic records from 71 National Health Service Trusts in England. A data set was established by collating all data items found in an initial tranche of 28 records. All 71 records were subsequently analysed for each data item in this data set. We found significant variation: the most populated record included 216 data items and the least included 38 data items: a greater than five-fold variation. There was significant variation in the inclusion of data items commonly considered important to patient safety; 42% of records omitted documentation of fasting status, 72% omitted documentation of a discussion around the risk of accidental awareness during general anaesthesia, 92% omitted documentation of quantitative neuromuscular blockade monitoring and 63% omitted documentation for 'Stop Before You Block' when performing regional anaesthesia. The study highlights significant variability in the composition of anaesthetic records across England which may impact on its value as a data repository, an action trigger, a medicolegal account, and a tool to facilitate safe handover. Standardisation of the anaesthetic record or the establishment of standards of recording would help to allay potential risks to patient safety and assist in guiding future procurement of electronic solutions for anaesthetic records.

Methods of the 7th National Audit Project (NAP7) of the Royal College of Anaesthetists: peri-operative cardiac arrest.

Cardiac arrest in the peri-operative period is rare but associated with significant morbidity and mortality. Current reporting systems do not capture many such events, so there is an incomplete understanding of incidence and outcomes. As peri-operative cardiac arrest is rare, many hospitals may only see a small number of cases over long periods, and anaesthetists may not be involved in such cases for years. Therefore, a large-scale prospective cohort is needed to gain a deep understanding of events leading up to cardiac arrest, management of the arrest itself and patient outcomes. Consequently, the Royal College of Anaesthetists chose peri-operative cardiac arrest as the 7th National Audit Project topic. The study was open to all UK hospitals offering anaesthetic services and had a three-part design. First, baseline surveys of all anaesthetic departments and anaesthetists in the UK, examining respondents' prior peri-operative cardiac arrest experience, resuscitation training and local departmental preparedness. Second, an activity survey to record anonymised details of all anaesthetic activity in each site over 4 days, enabling national estimates of annual anaesthetic activity, complexity and complication rates. Third, a case registry of all instances of peri-operative cardiac arrest in the UK, reported confidentially and anonymously, over 1 year starting 16 June 2021, followed by expert review using a structured process to minimise bias. The definition of peri-operative cardiac arrest was the delivery of five or more chest compressions and/or defibrillation in a patient having a procedure under the care of an anaesthetist. The peri-operative period began with the World Health Organization 'sign-in' checklist or first hands-on contact with the patient and ended either 24 h after the patient handover (e.g. to the recovery room or intensive care unit) or at discharge if this occured earlier than 24 h. These components described the epidemiology of peri-operative cardiac arrest in the UK and provide a basis for developing guidelines and interventional studies.

Bioreactor design and validation for manufacturing strategies in tissue engineering.

The fields of regenerative medicine and tissue engineering offer new therapeutic options to restore, maintain or improve tissue function following disease or injury. To maximize the biological function of a tissue-engineered clinical product, specific conditions must be maintained within a bioreactor to allow the maturation of the product in preparation for implantation. Specifically, the bioreactor should be designed to mimic the mechanical, electrochemical and biochemical environment that the product will be exposed to in vivo. Real-time monitoring of the functional capacity of tissue-engineered products during manufacturing is a critical component of the quality management process. The present review provides a brief overview of bioreactor engineering considerations. In addition, strategies for bioreactor automation, in-line product monitoring and quality assurance are discussed.

BRD4 Prevents R-Loop Formation and Transcription-Replication Conflicts by Ensuring Efficient Transcription Elongation.

Effective spatio-temporal control of transcription and replication during S-phase is paramount to maintaining genomic integrity and cell survival. Dysregulation of these systems can lead to conflicts between the transcription and replication machinery, causing DNA damage and cell death. BRD4 allows efficient transcriptional elongation by stimulating phosphorylation of RNA polymerase II (RNAPII). We report that bromodomain and extra-terminal domain (BET) protein loss of function (LOF) causes RNAPII pausing on the chromatin and DNA damage affecting cells in S-phase. This persistent RNAPII-dependent pausing leads to an accumulation of RNA:DNA hybrids (R-loops) at sites of BRD4 occupancy, leading to transcription-replication conflicts (TRCs), DNA damage, and cell death. Finally, our data show that the BRD4 C-terminal domain, which interacts with P-TEFb, is required to prevent R-loop formation and DNA damage caused by BET protein LOF.

B7-H3-redirected chimeric antigen receptor T cells target glioblastoma and neurospheres.

BACKGROUND: The dismal survival of glioblastoma (GBM) patients urgently calls for the development of new treatments. Chimeric antigen receptor T (CAR-T) cells are an attractive strategy, but preclinical and clinical studies in GBM have shown that heterogeneous expression of the antigens targeted so far causes tumor escape, highlighting the need for the identification of new targets. We explored if B7-H3 is a valuable target for CAR-T cells in GBM. METHODS: We compared mRNA expression of antigens in GBM using TCGA data, and validated B7-H3 expression by immunohistochemistry. We then tested the antitumor activity of B7-H3-redirected CAR-T cells against GBM cell lines and patient-derived GBM neurospheres in vitro and in xenograft murine models. FINDINGS: B7-H3 mRNA and protein are overexpressed in GBM relative to normal brain in all GBM subtypes. Of the 46 specimens analyzed by immunohistochemistry, 76% showed high B7-H3 expression, 22% had detectable, but low B7-H3 expression and 2% were negative, as was normal brain. All 20 patient-derived neurospheres showed ubiquitous B7-H3 expression. B7-H3-redirected CAR-T cells effectively targeted GBM cell lines and neurospheres in vitro and in vivo. No significant differences were found between CD28 and 4-1BB co-stimulation, although CD28-co-stimulated CAR-T cells released more inflammatory cytokines. INTERPRETATION: We demonstrated that B7-H3 is highly expressed in GBM specimens and neurospheres that contain putative cancer stem cells, and that B7-H3-redirected CAR-T cells can effectively control tumor growth. Therefore, B7-H3 represents a promising target in GBM. FUND: Alex's Lemonade Stand Foundation; Il Fondo di Gio Onlus; National Cancer Institute; Burroughs Wellcome Fund.

Cross-sectional study of the prevalence, causes and management of hospital-onset diarrhoea.

BACKGROUND: The National Health Service in England advises hospitals collect data on hospital-onset diarrhoea (HOD). Contemporaneous data on HOD are lacking. AIM: To investigate prevalence, aetiology and management of HOD on medical, surgical and elderly-care wards. METHODS: A cross-sectional study in a volunteer sample of UK hospitals, which collected data on one winter and one summer day in 2016. Patients admitted ≥72 h were screened for HOD (definition: ≥2 episodes of Bristol Stool Type 5-7 the day before the study, with diarrhoea onset >48 h after admission). Data on HOD aetiology and management were collected prospectively. FINDINGS: Data were collected on 141 wards in 32 hospitals (16 acute, 16 teaching). Point-prevalence of HOD was 4.5% (230/5142 patients; 95% confidence interval (CI) 3.9-5.0%). Teaching hospital HOD prevalence (5.9%, 95% CI 5.1-6.9%) was twice that of acute hospitals (2.8%, 95% CI 2.1-3.5%; odds ratio 2.2, 95% CI 1.7-3.0). At least one potential cause was identified in 222/230 patients (97%): 107 (47%) had a relevant underlying condition, 125 (54%) were taking antimicrobials, and 195 (85%) other medication known to cause diarrhoea. Nine of 75 tested patients were Clostridium difficile toxin positive (4%). Eighty (35%) patients had a documented medical assessment of diarrhoea. Documentation of HOD in medical notes correlated with testing for C. difficile (78% of those tested vs 38% not tested, P<0.001). One-hundred and forty-four (63%) patients were not isolated following diarrhoea onset. CONCLUSION: HOD is a prevalent symptom affecting thousands of patients across the UK health system each day. Most patients had multiple potential causes of HOD, mainly iatrogenic, but only a third had medical assessment. Most were not tested for C. difficile and were not isolated.

Comparison of multiple electrode aggregometry with lumi-aggregometry for the diagnosis of patients with mild bleeding disorders.

Essentials There is a clinical need for new technologies to measure platelet function in whole blood. Mild bleeding disorders were evaluated using multiple electrode aggregometry (MEA). MEA is insensitive at detecting patients with mild platelet function and secretion defects. More studies are required to investigate MEA in patients with a defined set of platelet disorders. SUMMARY: Background Multiple electrode aggregometry (MEA) measures changes in electrical impedance caused by platelet aggregation in whole blood. This approach is faster, more convenient and offers the advantage over light transmission aggregometry (LTA) of assessing platelet function in whole blood and reducing preanalytical errors associated with preparation of platelet-rich plasma (PRP). Several studies indicate the utility of this method in assessing platelet inhibition in individuals taking antiplatelet agents (e.g. aspirin and clopidogrel). Objective Our current study sought to evaluate the ability of MEA in diagnosing patients with mild bleeding disorders by comparison with light transmission lumi-aggregometry (lumi-LTA). Methods Forty healthy subjects and 109 patients with a clinical diagnosis of a mild bleeding disorder were recruited into the UK Genotyping and Phenotyping of Platelets study (GAPP, ISRCTN 77951167). MEA was performed on whole blood using one or two concentrations of ADP, PAR-1 peptide, arachidonic acid and collagen. Lumi-LTA was performed in PRP using several concentrations of ADP, adrenaline, arachidonic acid, collagen, PAR-1 peptide and ristocetin. Results Of 109 patients tested, 54 (49%) patients gave abnormal responses by lumi-LTA to one or more agonists. In contrast, only 16 (15%) patients were shown to have abnormal responses to one or more agonists by MEA. Conclusions In this study we showed that MEA is less sensitive in identifying patients with abnormal platelet function relative to lumi-LTA.

Drivers of choice for fluid milk versus plant-based alternatives: What are consumer perceptions of fluid milk?

Fluid milk consumption has declined for decades while consumption of nondairy alternatives has increased. A better understanding of why consumers purchase fluid milk or nondairy alternatives is needed to assist increased sales of milk or maintain sales without further decline. The objective of this study was to determine the extrinsic attributes that drive purchase within each product category. The second objective was to determine the personal values behind the purchase of each beverage type to give further understanding why particular attributes are important. An online conjoint survey was launched with 702 dairy consumers, 172 nondairy consumers, and 125 consumers of both beverages. Individual means-end chain interviews were conducted with fluid milk consumers (n = 75), plant-based alternative consumers (n = 68), and consumers of both beverages (n = 78). Fat content was the most important attribute for dairy milk followed by package size and label claims. Consumers of fluid milk preferred 1 or 2% fat content, gallon, or half-gallon packaging, conventionally pasteurized store-brand milk. Sugar level was the most important attribute for plant-based beverages, followed by plant source and package size. Almond milk was the most desirable plant source, and half-gallon packaging was the most preferred packaging. Means-end chain interviews results suggested that maintaining a balanced diet and healthy lifestyle was important to all consumer groups. Lactose free was an important attribute for plant-based alternative consumers and consumers of both dairy and nondairy. A distinguishing characteristic of those who only drank nondairy plant-based alternatives was that plant-based beverages contributed to a goal to consume less animal products, beliefs about animal mistreatment, and perceived lesser effect on the environment than fluid milk. Unique to fluid milk consumers was that fluid milk was perceived as a staple food item. These results suggest that the dairy industry should focus on the nutrition value of milk and educating consumers about misconceptions regarding dairy milk. Future beverage innovation should include the development of lactose-free milk that is also appealing to consumers in flavor.

Amphipathic polyproline peptides stimulate cholesterol efflux by the ABCA1 transporter.

ApoA-I mimetics are short synthetic peptides that contain an amphipathic α-helix and stimulate cholesterol efflux by the ABCA1 transporter in a detergent-like extraction mechanism. We investigated the use of amphipathic peptides with a polypro helix for stimulating cholesterol efflux by ABCA1. Polypro peptides were synthesized with modified prolines, containing either a hydrophobic phenyl group (Prop) or a polar N-acetylgalactosamine (Prog) attached to the pyrrolidine ring and were designated as either PP-2, 3, 4, or 5, depending on the number of 3 amino acid repeat units (Prop-Prog-Prop). Based on molecular modeling, these peptides were predicted to be relatively rigid and to bind to a phospholipid bilayer. By CD spectroscopy, PP peptides formed a Type-II polypro helix in an aqueous solution. PP-2 was inactive in promoting cholesterol efflux, but peptides with more than 2 repeat units were active. PP-4 showed a similar Vmax as a much longer amphipathic α-helical peptide, containing 37 amino acids, but had a Km that was approximately 20-fold lower. PP peptides were specific in that they did not stimulate cholesterol efflux from cells not expressing ABCA1 and were also non-cytotoxic. Addition of PP-3, 4 and 5 to serum promoted the formation of smaller size HDL species (7 nM) and increased its capacity for ABCA1-dependent cholesterol efflux by approximately 20-35% (p < 0.05). Because of their relatively small size and increased potency, amphipathic peptides with a polypro helix may represent an alternative structural motif for the development of apoA-I mimetic peptides.

Use of next-generation sequencing and candidate gene analysis to identify underlying defects in patients with inherited platelet function disorders.

BACKGROUND: Inherited platelet function disorders (PFDs) are heterogeneous, and identification of the underlying genetic defects is difficult when based solely on phenotypic and clinical features of the patient. OBJECTIVE: To analyze 329 genes regulating platelet function, number, and size in order to identify candidate gene defects in patients with PFDs. PATIENTS/METHODS: Targeted analysis of candidate PFD genes was undertaken after next-generation sequencing of exomic DNA from 18 unrelated index cases with PFDs who were recruited into the UK Genotyping and Phenotyping of Platelets (GAPP) study and diagnosed with platelet abnormalities affecting either Gi signaling (n = 12) or secretion (n = 6). The potential pathogenicity of candidate gene defects was assessed using computational predictive algorithms. RESULTS: Analysis of the 329 candidate PFD genes identified 63 candidate defects, affecting 40 genes, among index cases with Gi signaling abnormalities, while 53 defects, within 49 genes, were identified among patients with secretion abnormalities. Homozygous gene defects were more commonly associated with secretion abnormalities. Functional annotation analysis identified distinct gene clusters in the two patient subgroups. Thirteen genes with significant annotation enrichment for 'intracellular signaling' harbored 16 of the candidate gene defects identified in nine index cases with Gi signaling abnormalities. Four gene clusters, representing 14 genes, with significantly associated gene ontology annotations were identified among the cases with secretion abnormalities, the most significant association being with 'establishment of protein localization.' CONCLUSION: Our findings demonstrate the genetic complexity of PFDs and highlight plausible candidate genes for targeted analysis in patients with platelet secretion and Gi signaling abnormalities.

Efficacy of a basal bolus insulin protocol to treat prednisolone-induced hyperglycaemia in hospitalised patients.

BACKGROUND/AIM: Few studies have specifically investigated treatment of prednisolone-induced hyperglycaemia. AIM: To determine if a basal bolus insulin (BBI) protocol for inpatient hyperglycaemia is effective in patients prescribed acute prednisolone for an inflammatory disease. METHODS: In a cross-sectional study, 66 patients with type 2 diabetes admitted to a general medical ward and treated with BBI for up to 5 days were studied. Twenty-four patients were taking prednisolone ≥10 mg/day to treat an acute inflammatory disease. The remaining 42 patients were a control group. The primary outcome was mean daily blood glucose level. RESULTS: There were no significant differences in glycosylated haemoglobin (8.1 ± 1.0 vs 8.1 ± 1.6%, P = 0.88), age (77 ± 11 vs 75 ± 14 years, P = 0.57), male sex (63 vs 60%, P = 0.81) or body mass index (30.0 ± 5.3 vs 30.2 ± 11.5 kg/m(2) , P = 0.90) between patients taking prednisolone and controls. Mean daily glucose concentration was higher in patients taking prednisolone than in controls (12.2 ± 0.3 vs 10.0 ± 0.1 mmol/L, P < 0.001). Blood glucose level was higher in patients on prednisolone at 1700 h (14.6 ± 0.6 vs 10.3 ± 0.3 mmol/L, P < 0.001) and 2100 h (14.5 ± 0.6 vs 10.5 ± 0.3 mmol/L, P < 0.001), with no significant differences at 0700 h and 1200 h. These findings occurred despite patients taking prednisolone receiving a higher daily insulin dose than controls (0.67-0.70 vs 0.61-0.65 U/kg, P = 0.001) because of higher doses of ultra-rapid-acting insulin at 1200 h and 1700 h. CONCLUSIONS: Hospitalised patients taking prednisolone had substantial afternoon and evening hyperglycaemia despite receiving BBI via a protocol for inpatient hyperglycaemia. Specific insulin regimens for prednisolone-induced hyperglycaemia are needed that recommend more insulin during this time period.

Identification of clinical isolates of anaerobic bacteria using matrix-assisted laser desorption ionization-time of flight mass spectrometry.

We evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) for the rapid identification of anaerobic bacteria that had been isolated from clinical specimens and previously identified by 16s rRNA sequencing. The Bruker Microflex MALDI-TOF instrument with the Biotyper Software was used. We tested 152 isolates of anaerobic bacteria from 24 different genera and 75 different species. A total of 125 isolates (82%) had Biotyper software scores greater than 2.0 and the correct identification to genus and species was made by MALDI-TOF for 120 (79%) of isolates. Of the 12 isolates with a score between 1.8 and 2.0, 2 (17%) organisms were incorrectly identified by MALDI-TOF. Only 15 (10%) isolates had a score less than 1.8 and MALDI-TOF gave the wrong genus and species for four isolates, the correct genus for two isolates, and the correct genus and species for nine isolates. Therefore, we found the Bruker MALDI-TOF MicroFlex LT with an expanded database and the use of bacteria extracts rather than whole organisms correctly identified 130 of 152 (86%) isolates to genus and species when the cut-off for an acceptable identification was a spectrum score ≥1.8.

Image quality improvement in megavoltage cone beam CT using an imaging beam line and a sintered pixelated array system.

PURPOSE: To quantify the improvement in megavoltage cone beam computed tomography (MVCBCT) image quality enabled by the combination of a 4.2 MV imaging beam line (IBL) with a carbon electron target and a detector system equipped with a novel sintered pixelated array (SPA) of translucent Gd(2)O(2)S ceramic scintillator. Clinical MVCBCT images are traditionally acquired with the same 6 MV treatment beam line (TBL) that is used for cancer treatment, a standard amorphous Si (a-Si) flat panel imager, and the Kodak Lanex Fast-B (LFB) scintillator. The IBL produces a greater fluence of keV-range photons than the TBL, to which the detector response is more optimal, and the SPA is a more efficient scintillator than the LFB. METHODS: A prototype IBL + SPA system was installed on a Siemens Oncor linear accelerator equipped with the MVision(TM) image guided radiation therapy (IGRT) system. A SPA strip consisting of four neighboring tiles and measuring 40 cm by 10.96 cm in the crossplane and inplane directions, respectively, was installed in the flat panel imager. Head- and pelvis-sized phantom images were acquired at doses ranging from 3 to 60 cGy with three MVCBCT configurations: TBL + LFB, IBL + LFB, and IBL + SPA. Phantom image quality at each dose was quantified using the contrast-to-noise ratio (CNR) and modulation transfer function (MTF) metrics. Head and neck, thoracic, and pelvic (prostate) cancer patients were imaged with the three imaging system configurations at multiple doses ranging from 3 to 15 cGy. The systems were assessed qualitatively from the patient image data. RESULTS: For head and neck and pelvis-sized phantom images, imaging doses of 3 cGy or greater, and relative electron densities of 1.09 and 1.48, the CNR average improvement factors for imaging system change of TBL + LFB to IBL + LFB, IBL + LFB to IBL + SPA, and TBL + LFB to IBL + SPA were 1.63 (p < 10(- 8)), 1.64 (p < 10(- 13)), 2.66 (p < 10(- 9)), respectively. For all imaging doses, soft tissue contrast was more easily differentiated on IBL + SPA head and neck and pelvic images than TBL + LFB and IBL + LFB. IBL + SPA thoracic images were comparable to IBL + LFB images, but less noisy than TBL + LFB images at all imaging doses considered. The mean MTFs over all imaging doses were comparable, at within 3%, for all imaging system configurations for both the head- and pelvis-sized phantoms. CONCLUSIONS: Since CNR scales with the square root of imaging dose, changing from TBL + LFB to IBL + LFB and IBL + LFB to IBL + SPA reduces the imaging dose required to obtain a given CNR by factors of 0.38 and 0.37, respectively. MTFs were comparable between imaging system configurations. IBL + SPA patient image quality was always better than that of the TBL + LFB system and as good as or better than that of the IBL + LFB system, for a given dose.

Helix stabilization of amphipathic peptides by hydrocarbon stapling increases cholesterol efflux by the ABCA1 transporter.

Apolipoprotein mimetic peptides are short amphipathic peptides that efflux cholesterol from cells by the ABCA1 transporter and are being investigated as therapeutic agents for cardiovascular disease. We examined the role of helix stabilization of these peptides in cholesterol efflux. A 23-amino acid long peptide (Ac-VLEDSFKVSFLSALEEYTKKLNTQ-NH2) based on the last helix of apoA-I (A10) was synthesized, as well as two variants, S1A10 and S2A10, in which the third and fourth and third and fifth turn of each peptide, respectively, were covalently joined by hydrocarbon staples. By CD spectroscopy, the stapled variants at 24 °C were more helical in aqueous buffer than A10 (A10 17%, S1A10 62%, S2A10 97%). S1A10 and S2A10 unlike A10 were resistant to proteolysis by pepsin and chymotrypsin. S1A10 and S2A10 showed more than a 10-fold increase in cholesterol efflux by the ABCA1 transporter compared to A10. In summary, hydrocarbon stapling of amphipathic peptides increases their helicity, makes them resistant to proteolysis and enhances their ability to promote cholesterol efflux by the ABCA1 transporter, indicating that this peptide modification may be useful in the development of apolipoprotein mimetic peptides.

Salty taste in dairy foods: can we reduce the salt?

Sodium can be found in many sources of the US diet. Dietary guidelines currently suggest a maximum intake of 2,300 mg of sodium (6g of sodium chloride) per day, whereas the average consumer intake is 3,600 mg of sodium (9 g of sodium chloride) per day. The main health concern with high consumption of sodium is hypertension. The objectives of this study were to identify the salty taste intensity of sodium chloride in water and various dairy food matrices, and to identify the just-noticeable difference in concentration at which consumers noticed a decrease in salty taste in these food products. Solutions and food products (water, cheese sauce, cottage cheese, and milk-based soup) were prepared with sodium chloride ranging in concentration from 0.008 to 0.06 M. Seventeen panelists evaluated the salty intensity of each product in triplicate using a magnitude estimation scale. In subsequent tests, panelists (n=50) evaluated salty intensity of these food products in separate sessions using an ascending force choice method to determine the just-noticeable difference. Consumer acceptance tests (n=75 consumers) were conducted with cottage cheeses with and without sodium reductions and under conditions with and without health benefits of sodium reduction. The magnitude estimation scale data were log-transformed, and all data were analyzed by ANOVA with Fisher's least significant difference for means separation. The linear proportion of the power function in the salty taste intensity curve for sodium chloride solutions and the 3 foods was between 0.03 and 0.20 M. Consumers were able to notice and correctly identify reductions in salt concentration of less than 20% in all products. When consumers were informed of sodium reduction and its health benefits before tasting cottage cheese with lower sodium (4-12%), overall liking scores for the lower sodium cottage cheeses were not different from higher sodium cottage cheeses. These results suggest that reducing sodium in cheese sauce, cottage cheese, and milk-based soups may be challenging and that exploration of sodium chloride alternatives in these foods is warranted. Appropriate product positioning or advertising may be beneficial to consumer acceptance of lower sodium types of products.

Type IIA topoisomerase inhibition by a new class of antibacterial agents.

Despite the success of genomics in identifying new essential bacterial genes, there is a lack of sustainable leads in antibacterial drug discovery to address increasing multidrug resistance. Type IIA topoisomerases cleave and religate DNA to regulate DNA topology and are a major class of antibacterial and anticancer drug targets, yet there is no well developed structural basis for understanding drug action. Here we report the 2.1 A crystal structure of a potent, new class, broad-spectrum antibacterial agent in complex with Staphylococcus aureus DNA gyrase and DNA, showing a new mode of inhibition that circumvents fluoroquinolone resistance in this clinically important drug target. The inhibitor 'bridges' the DNA and a transient non-catalytic pocket on the two-fold axis at the GyrA dimer interface, and is close to the active sites and fluoroquinolone binding sites. In the inhibitor complex the active site seems poised to cleave the DNA, with a single metal ion observed between the TOPRIM (topoisomerase/primase) domain and the scissile phosphate. This work provides new insights into the mechanism of topoisomerase action and a platform for structure-based drug design of a new class of antibacterial agents against a clinically proven, but conformationally flexible, enzyme class.

Comparison of two methods to explore consumer preferences for cottage cheese.

In the past 2 decades, total sales of cottage cheese have declined 17% despite increases in sales for low-fat cottage cheese. There are no recent published studies investigating consumer preferences for cottage cheese. This study was conducted to identify and define sensory characteristics of commercial cottage cheese and to compare 2 approaches for characterizing consumer preferences: traditional preference mapping and a new composite qualitative approach, qualitative multivariate analysis (QMA). A sensory language was identified to document the sensory properties (visual, flavor, and texture) of cottage cheeses. Twenty-six commercial cottage cheeses with variable fat contents (4, 2, 1, and 0% fat) were evaluated by trained panelists using the sensory language. Eight representative cottage cheeses were selected for consumer acceptance testing (n = 110) and QMA with consumer home usage testing (n = 12), followed by internal and external preference mapping to identify key drivers. Principal component analysis of descriptive data indicated that cottage cheeses were primarily differentiated by cooked, milkfat, diacetyl, and acetaldehyde flavors and salty taste, and by firmness, smoothness, tackiness, curd size, and adhesiveness texture attributes. Similar drivers of liking (diacetyl and milkfat flavors, smooth texture, and mouthcoating) were identified by both consumer research techniques. However, the QMA technique identified controversial distinctions among the cottage cheeses and the influence of brand and pricing. These results can be used by processors to promote cottage cheese sales.

Mapping differences in consumer perception of sharp cheddar cheese in the United States.

There is tremendous variability in flavor profiles of sharp or aged U.S. cheddar cheese due to varied practices among commercial facilities and the lack of legal definitions for these terms. This study explored U.S. consumer perception and liking of commercial sharp or aged cheddar cheese profiles. Flavor profiles of 29 representative sharp cheddar cheeses were documented by descriptive sensory analysis with a trained panel. A total of 9 representative cheddar cheeses were selected and evaluated by consumers in 3 regional locations: east coast (Raleigh, N.C.; n = 150), midwest (Champaign, Ill.; n = 75), and west coast (Pullman, Wash.; n = 100). Consumers assessed the cheeses for overall liking and other consumer liking attributes. External preference mapping revealed 5 distinct consumer segments. The segment membership distribution between east coast and midwest consumers was similar while the west coast distribution was distinct (P < 0.05). A larger proportion of west coast consumers were present in segment 3, which consisted of consumers with specific likes for cheeses characterized by intense flavors of free fatty acid, brothy, and nutty flavors and salty and sour tastes. Consumer preferences in other segments differed from segment 3 due to their liking of at least 1 sensory attribute generally associated with young or mild cheddar cheese flavor. Key drivers of liking for these segments included whey flavor for segments 1 and 4 and milkfat flavor for segment 5. Segment 2 consumers liked most of the cheeses tested except those with dominant whey flavor. A sharp or aged cheddar cheese label means different things to different consumers and liking profiles are not defined by consumer location.

Consumer preferences for mild cheddar cheese flavors.

Flavor is an important factor in consumer selection of cheeses. Mild Cheddar cheese is the classification used to describe Cheddar cheese that is not aged extensively and has a "mild" flavor. However, there is no legal definition or age limit for Cheddar cheese to be labeled mild, medium, or sharp, nor are the flavor profiles or flavor expectations of these cheeses specifically defined. The objectives of this study were to document the distinct flavor profiles among commercially labeled mild Cheddar cheeses, and to characterize if consumer preferences existed for specific mild Cheddar cheese flavors or flavor profiles. Flavor descriptive sensory profiles of a representative array of commercial Cheddar cheeses labeled as mild (n= 22) were determined using a trained sensory panel and an established cheese flavor sensory language. Nine representative Cheddar cheeses were selected for consumer testing. Consumers (n= 215) assessed the cheeses for overall liking and other consumer liking attributes. Internal preference mapping, cluster analysis, and discriminant analysis were conducted. Mild Cheddar cheeses were diverse in flavor with many displaying flavors typically associated with more age. Four distinct consumer clusters were identified. The key drivers of liking for mild Cheddar cheese were: color, cooked/milky, whey and brothy flavors, and sour taste. Consumers have distinct flavor and color preferences for mild Cheddar cheese. These results can help manufacturers understand consumer preferences for mild Cheddar cheese.

Sources of umami taste in Cheddar and Swiss cheeses.

Umami plays an important role in the flavor of many cheese varieties. The purpose of this study was to identify the compound(s) responsible for umami taste in Cheddar and Swiss cheeses. Four Cheddar and 4 Swiss cheeses (two with low umami intensity and two with high umami intensity from each type) were selected using a trained sensory panel. Monosodium glutamate (MSG), disodium 5'-inosine monophosphate (IMP), disodium 5'-guanosine monophosphate (GMP), sodium chloride, lactic acid, propionic acid, and succinic acid were quantified in the cheeses instrumentally. Taste thresholds (best estimate thresholds, BETs) were determined for each compound in water. Subsequently, a trained descriptive sensory analysis panel evaluated each compound in odor-free water across threshold concentrations to confirm that the thresholds were based on umami and not some other stimuli. Model system studies with trained panelists were then conducted with each compound individually or all compounds together. Comparison of analytical data and sensory thresholds indicated that IMP and GMP thresholds were 100-fold higher than their concentrations in cheese. All other compounds contributed some umami taste within their concentration range in umami cheeses. Sensory analysis of model cheeses revealed that glutamic acid played the largest role in umami taste of both Cheddar and Swiss cheeses while succinic and propionic acids contributed to umami taste in Swiss cheeses. Knowledge of the key compounds associated with umami taste in cheeses will aid in the identification of procedures to enhance formation of this taste in cheese.