Ethnography and medicine: the utility of positivist methods in research.

This commentary discusses the methodological utility of ethnography within the medical space. Whilst a general consensus affirms that ethnography aligns with qualitative approaches, as identified within the existing medical literature, here, we demonstrate how quantitative [positivist] methods can also be incorporated. This paper begins by contextualising ethnographic approaches within medical contexts by demonstrating its empirical value within the existing literature. Next, we discuss the interconnection between the practice of 'doctoring' and ethnographic research, whereby doctors themselves use forms of inductive and deductive reasoning to treat and manage patients in their everyday context. This philosophical discussion not only links to the everyday practice of medical practitioners, but also critically reflects on the role of the first author, as a diagnostic radiographer. Lastly, this paper identifies the virtues of ethnographic research for medical students and/or medical doctors whereby the combination of qualitative and quantitative methods (within an ethnographic methodology) can lead to new empirical and methodological insights, enabling the creation of alternate research strategies and evidence. This methodological strategy may be best considered amongst medical students and/or early career medical researchers, but we also anticipate it to resonate and open further discussion with experienced medical practitioners and researchers transnationally.

Development of comparable algorithms to measure primary care indicators using administrative health data across three Canadian provinces.

INTRODUCTION: Performance measurement has been recognized as key to transforming primary care (PC). Yet, performance reporting in PC lags behind even though high-performing PC is foundational to an effective and efficient health care system. OBJECTIVES: We used administrative data from three Canadian provinces, British Columbia, Ontario and Nova Scotia, to: 1) identify and develop a core set of PC performance indicators using administrative data and 2) examine their ability to capture PC performance. METHODS: Administrative data used included Physician Billings, Discharge Abstract Database, the National Ambulatory Care and Reporting System database, Census and Vital Statistics. Indicators were compiled based on a literature review of PC indicators previously developed with administrative data available in Canada (n=158). We engaged in iterative discussions to assess data conformity, completeness, and plausibility of results in all jurisdictions. Challenges to creating comparable algorithms were examined through content analysis and research team discussions, which included clinicians, analysts, and health services researchers familiar with PC. RESULTS: Our final list included 21 PC performance indicators pertaining to 1) technical care (n=4), 2) continuity of care (n=6), and 3) health services utilization (n=11). Establishing comparable algorithms across provinces was possible though time intensive. A major challenge was inconsistent data elements. Ease of data access, and a deep understanding of the data and practice context, was essential for selecting the most appropriate data elements. CONCLUSIONS: This project is unique in creating algorithms to measure PC performance across provinces. It was essential to balance internal validity of the indicators within a province and external validity across provinces. The intuitive desire of having the exact same coding across provinces was infeasible due to lack of standardized PC data. Rather, a context-tailored definition was developed for each jurisdiction. This work serves as an example for developing comparable PC performance indicators across different provincial/territorial jurisdictions.

Attitudes and perceptions of radiographers applying lead (Pb) protection in general radiography: An ethnographic study.

INTRODUCTION: Since the discovery of X-rays by Rontgen in 1895, lead (Pb) has been used to limit ionising radiation for both operators and patients due to its high density and high atomic number (Z = 82). This study explores the attitudes and perceptions of diagnostic radiographers applying Pb protection during general radiographic examinations, an area underexplored within a contemporary radiographic environment(s). METHODS: This paper presents findings from a wider ethnographic study undertaken in the United Kingdom (UK). The use of participant observation and semi-structured interviews were the methods of choice. Participant observation enabled the overt researcher to uncover whether Pb remained an essential tool for radiographers. Semi-structured interviews later supported or refuted the limited use of Pb protection by radiographers. These methods enabled the construction of original phenomena within the clinical environment. RESULTS: Two themes are discussed. Firstly, radiographers, underpinned by their own values and beliefs towards radiation risk, identify a dichotomy of applying Pb protection. The cessation of Pb may be linked to cultural myths, relying on 'word of mouth' of peers and not on the existing evidence-base. Secondly, radiographers acknowledge that protecting pregnant patients may be primarily a 'personal choice' in clinical environments, which can alter if a patient requests 'are you going to cover me up?' CONCLUSION: This paper concludes by affirming the complexities surrounding Pb protection in clinical environments. It is proposed that the use of Pb protection in general radiography may become increasingly fragmented in the future if radiographers continue rely on cultural norms.

Image acquisition in general radiography: The utilisation of DDR.

OBJECTIVE: This article explores image acquisition with DDR. General radiographic technology continues to advance therefore it remains paramount to continually reflect on DDR hardware and software amongst radiographers in an imaging modality that constitutes approximately 90% of all radiological examinations. METHOD: This article reports findings from a wider ethnographic study of two general radiography environments in the United Kingdom (UK). Participant observation and semi-structured interviews were the methods used to uncover original data. RESULTS: Two key themes are discussed. Firstly, 'the extent of DDR knowledge' amongst radiographers is examined. The findings uncover that not all radiographers have an adequate knowledge base with DDR technology. Secondly, 'pitfalls and near misses with DDR' is discussed. This theme highlights the potential danger of radiographers 'over-repeating' X-ray examinations, coincided with the occurrence of radiological incidents whereby a patient is exposed to ionising radiation with no added benefit. CONCLUSION: This paper concludes by challenging the current 'skill base' to operate DDR equipment. In addition, new pitfalls and near misses are highlighted, which may help forestall radiation incidents in the future. Dose and image optimisation remain central tenets to the role of the radiographer. ADVANCES IN KNOWLEDGE: Few studies have challenged image acquisition with DDR. This study adds to existing knowledge by uncovering original phenomena that may initiate discussions within the radiography community and continually enhance healthcare delivery.

An accessible pharmacodynamic transcriptional biomarker for notch target engagement.

γ-Secretase mediates amyloid production in Alzheimer's disease (AD) and oncogenic activity of Notch. γ-Secretase inhibitors (GSIs) are thus of interest for AD and oncology. A peripheral biomarker of Notch activity would aid determination of the therapeutic window and dosing regimen for GSIs, given toxicities associated with chronic Notch inhibition. This study examined the effects of GSI MK-0752 on blood and hair follicle transcriptomes in healthy volunteers. The effects of a structurally diverse GSI on rhesus blood and hair follicles were also compared. Significant dose-related effects of MK-0752 on transcription were observed in hair follicles, but not blood. The GSI biomarker identified in follicles exhibited 100% accuracy in a clinical test cohort, and was regulated in rhesus by a structurally diverse GSI. This study identified a translatable, accessible pharmacodynamic biomarker of GSI target engagement and provides proof of concept of hair follicle RNA as a translatable biomarker source.

Concordance study between the ParaDNA® Intelligence Test, a rapid DNA profiling assay, and a conventional STR typing kit (AmpFlSTR® SGM Plus®).

The ParaDNA® Intelligence Test enables STR profiling directly from human biological samples and evidence items collected from crime scene in 75min. Designed for non-expert use this system allows DNA information to be available to investigators before it would typically be available from a laboratory. The ParaDNA Intelligence Test system amplifies D3S1358, D8S119, D16S539, D18S1358 and TH01 STR loci and the gender typing locus amelogenin and detects the alleles present with HyBeacon® probes. Individual DNA samples from 381 UK Caucasian individuals were analysed using AmpFlSTR® SGM Plus® and the ParaDNA Intelligence Test with the derived STR profiles compared. Here we describe the high level of concordance demonstrated between the two systems and discuss this with reference to allele frequencies and the discriminatory power offered by the ParaDNA Intelligence Test.

BRAF mutant gastrointestinal stromal tumor: first report of regression with BRAF inhibitor dabrafenib (GSK2118436) and whole exomic sequencing for analysis of acquired resistance.

Activating oncogenic mutations of BRAF have been described in patients with gastrointestinal stromal tumor (GIST), but treatment of GIST with BRAF inhibitors and mechanisms of mediating the emergence of resistance in GIST have not been reported. Dabrafenib is a potent ATP-competitive inhibitor of BRAF kinase and is highly selective for mutant BRAF in kinase panel screening, cell lines, and xenografts. We report prolonged antitumor activity in the first patient with V600E BRAF-mutated GIST who was treated with a BRAF inhibitor. Whole exome sequencing performed in tumor tissue obtained at the time of progressive disease demonstrated a somatic gain-of-function PIK3CA mutation (H1047R) as well as a CDKN2A aberration, which may have contributed to eventual resistance to treatment.

Understanding the population structure of North American patients with cystic fibrosis.

It is generally presumed that the cystic fibrosis (CF) population is relatively homogeneous, and predominantly of European origin. The complex ethnic make-up observed in the CF patients collected by the North American CF Modifier Gene Consortium has brought this assumption into question, and suggested the potential for population substructure in the three CF study samples collected from North America. It is well appreciated that population substructure can result in spurious genetic associations. To understand the ethnic composition of the North American CF population, and to assess the need for population structure adjustment in genetic association studies with North American CF patients, genome-wide single-nucleotide polymorphisms on 3076 unrelated North American CF patients were used to perform population structure analyses. We compared self-reported ethnicity to genotype-inferred ancestry, and also examined whether geographic distribution and cystic fibrosis transmembrane regulator (CFTR) mutation type could explain the population structure observed. Although largely Caucasian, our analyses identified a considerable number of CF patients with admixed African-Caucasian, Mexican-Caucasian and Indian-Caucasian ancestries. Population substructure was present and comparable across the three studies of the consortium. Neither geographic distribution nor CFTR mutation type explained the population structure. Given the ethnic diversity of the North American CF population, it is essential to carefully detect, estimate and adjust for population substructure to guard against potential spurious findings in CF genetic association studies. Other Mendelian diseases that are presumed to predominantly affect single ethnic groups may also benefit from careful analysis of population structure.

A susceptibility gene for type 2 diabetes confers substantial risk for diabetes complicating cystic fibrosis.

AIMS/HYPOTHESIS: Insulin-requiring diabetes affects 25-50% of young adults with cystic fibrosis (CF). Although the cause of diabetes in CF is unknown, recent heritability studies in CF twins and siblings indicate that genetic modifiers play a substantial role. We sought to assess whether genes conferring risk for diabetes in the general population may play a risk modifying role in CF. METHODS: We tested whether a family history of type 2 diabetes affected diabetes risk in CF patients in 539 families in the CF Twin and Sibling family-based study. A type 2 diabetes susceptibility gene (transcription factor 7-like 2, or TCF7L2) was evaluated for association with diabetes in CF using 998 patients from the family-based study and 802 unrelated CF patients in an independent case-control study. RESULTS: Family history of type 2 diabetes increased the risk of diabetes in CF (OR 3.1; p = 0.0009). A variant in TCF7L2 associated with type 2 diabetes (the T allele at rs7903146) was associated with diabetes in CF in the family study (p = 0.004) and in the case-control study (p = 0.02; combined p = 0.0002). In the family-based study, variation in TCF7L2 increased the risk of diabetes about three-fold (HR 1.75 per allele, 95% CI 1.3-2.4; p = 0.0006), and decreased the mean age at diabetes diagnosis by 7 years. In CF patients not treated with systemic glucocorticoids, the effect of TCF7L2 was even greater (HR 2.9 per allele, 95% CI 1.7-4.9, p = 0.00011). CONCLUSIONS/INTERPRETATION: A genetic variant conferring risk for type 2 diabetes in the general population is a modifier of risk for diabetes in CF.

Flexibility of the cytoplasmic domain of the anion exchange protein, band 3, in human erythrocytes.

The rotational flexibility of the cytoplasmic domain of band 3, in the region that is proximal to the inner membrane surface, has been investigated using a combination of time-resolved optical anisotropy (TOA) and saturation-transfer electron paramagnetic resonance (ST-EPR) spectroscopies. TOA studies of rotational diffusion of the transmembrane domain of band 3 show a dramatic decrease in residual anisotropy following cleavage of the link with the cytoplasmic domain by trypsin (E. A. Nigg and R. J. Cherry, 1980, Proc. Natl. Acad. Sci. U.S.A. 77:4702-4706). This result is compatible with two independent hypotheses: 1) trypsin cleavage leads to dissociation of large clusters of band 3 that are immobile on the millisecond time scale, or 2) trypsin cleavage leads to release of a constraint to uniaxial rotational diffusion of the transmembrane domain. ST-EPR studies at X- and Q-band microwave frequencies detect rotational diffusion of the transmembrane domain of band 3 about the membrane normal axis of reasonably large amplitude that does not change upon cleavage with trypsin. These ST-EPR results are not consistent with dissociation of clusters of band 3 as a result of cleavage with trypsin. Global analyses of the ST-EPR data using a newly developed algorithm indicate that any constraint to rotational diffusion of the transmembrane domain of band 3 via interactions of the cytoplasmic domain with the membrane skeleton must be sufficiently weak to allow rotational excursions in excess of 32 degrees full-width for a square-well potential. In support of this result, analyses of the TOA data in terms of restricted amplitude uniaxial rotational diffusion models suggest that the membrane-spanning domain of that population of band 3 that is linked to the membrane skeleton is constrained to diffuse in a square-well of approximately 73 degrees full-width. This degree of flexibility may be necessary for providing the unique mechanical properties of the erythrocyte membrane.

Identification and functional characterization of thromboxane A2 receptors in Schwann cells.

Previous reports have demonstrated the presence of functional thromboxane A2 (TP) receptors in astrocytes and oligodendrocytes. In these experiments, the presence and function of TP receptors in primary rat Schwann cells (rSC) and a neurofibrosarcoma-derived human Schwann cell line (T265) was investigated. Immunocytochemical and immunoblot analyses using polyclonal anti-TP receptor antibodies demonstrate that both cell types express TP receptors. Treatment with the stable thromboxane A2 mimetic U46619 (10 microM) did not stimulate intracellular calcium mobilization in rSC, whereas T265 cells demonstrated a calcium response that was inhibited by prior treatment with TP receptor antagonists. U46619 also stimulated CREB phosphorylation on Ser133 in T265 cells and, to a lesser extent, in rSC. To identify potential mechanisms of CREB phosphorylation in rSC, we monitored intracellular cAMP levels following U46619 stimulation. Elevated levels of cAMP were detected in both rSC (20-fold) and T265 (15-fold) cells. These results demonstrate that TP receptor activation specifically stimulates CREB phosphorylation in T265 cells, possibly by a calcium- and/or cAMP-dependent mechanism. In contrast, TP receptor activation in rSC stimulates increases in cAMP and CREB phosphorylation but does not elicit changes in intracellular calcium.

Delayed benefits of paternal care in the burying beetle Nicrophorus vespilloides.

Burying beetles, Nicrophorus spp., inter the carcasses of small vertebrates as a food source for their offspring. Females can bury a carcass and rear a brood on it alone, but are frequently assisted by a male whose presence reduces the risk of the carcass being taken over by other beetles. However, the male often stays for longer than the carcass is vulnerable to take-over, and he cares for the brood without conferring any further benefits on it. In a laboratory experiment using N. vespilloides, we found that, in the absence of competitors, male assistance conferred no advantages on the brood for which he was caring, but significantly increased the subsequent reproductive success of his mate, in terms of the mass and rate of development of a second brood, reared alone. We suggest that this is due to a reduced parental effort of assisted females, who spent less time feeding offspring and more time resting than unassisted females whilst rearing their first broods. In the field, a female is unlikely to pair with the same male for consecutive broods, so we discuss the possible benefits a male may accrue from increasing his mate's reproductive success. We also discuss the relevance of these results to our understanding of the evolution of biparental care in birds. Copyright 2000 The Association for the Study of Animal Behaviour.

Oligomeric state of human erythrocyte band 3 measured by fluorescence resonance energy homotransfer.

The oligomeric state of the erythrocyte anion exchange protein, band 3, has been assayed by resonance energy homotransfer. Homotransfer between oligomeric subunits, labeled with eosin-5-maleimide at Lys430 in the transmembrane domain, has been demonstrated by steady-state and time-resolved fluorescence spectroscopy, and is readily observed by its depolarization of the eosin fluorescence. Polarized fluorescence measurements of HPLC-purified band 3 oligomers indicate that eosin homotransfer increases progressively with increasing species size. This shows that homotransfer also occurs between labeled band 3 dimers as well as within the dimers, making fluorescence anisotropy measurements sensitive to band 3 self-association. Treatment of ghost membranes with either Zn2+ or melittin, agents that cluster band 3, significantly decreases the anisotropy as a result of the increased homotransfer within the band 3 clusters. By comparison with the anisotropy of species of known oligomeric state, the anisotropy of erythrocyte ghost membranes at 37 degrees C is consistent with dimeric and/or tetrameric band 3, and does not require postulation of a fraction of large clusters. Proteolytic removal of the cytoplasmic domain of band 3, which significantly increases the rotational mobility of the transmembrane domain, does not affect its oligomeric state, as reported by eosin homotransfer. These results support a model in which interaction with the membrane skeleton restricts the mobility of band 3 without significantly altering its self-association state.

The identification and characterization of oligodendrocyte thromboxane A2 receptors.

The presence of functional thromboxane A2 receptors in neonatal rat oligodendrocytes and human oligodendroglioma cells was investigated using immunocytochemistry, ligand affinity chromatography, radioligand binding analysis, immunoblot analysis, and calcium mobilization studies. Immunocytochemical studies revealed the presence of receptor protein on both oligodendrocytes and human oligodendroglioma cells. Ligand affinity chromatography allowed for the purification of a protein with an electrophoretic mobility (55 kDa) indistinguishable from human platelet thromboxane A2 receptors. This affinity purified protein was immunoreactive against a polyclonal anti-thromboxane A2 receptor antibody. Intact human oligodendroglioma cells specifically bound [3H]SQ29,548 with a KD of 4 nM and were found to have approximately 3500 binding sites per cell. Human oligodendroglioma cells also demonstrated calcium mobilization in response to receptor activation with U46619. These results demonstrate the presence of a functional thromboxane A2 receptor in oligodendrocytes and are consistent with previous observations indicating a high density of thromboxane A2 receptors in myelinated brain and spinal cord fiber tracts.

Postcesarean analgesia with both epidural morphine and intravenous patient-controlled analgesia: neurobehavioral outcomes among nursing neonates.

UNLABELLED: Among nursing parturients after cesarean delivery, intravenous patient-controlled analgesia (PCA) with meperidine is associated with significantly more neonatal neurobehavioral depression than PCA with morphine. A single dose of epidural morphine (4 mg) decreases postcesarean opioid analgesic requirements and may reduce or prevent neonatal neurobehavioral depression associated with PCA meperidine. Prospectively, 102 term parturients underwent cesarean delivery with epidural anesthesia, 2% lidocaine and epinephrine 1:200,000. After umbilical cord clamping, each patient received epidural morphine 4 mg and was randomly allocated to receive either PCA meperidine or PCA morphine. Initial neonatal characteristics, included gestational age, Apgar scores, weight, and umbilical cord gas partial pressures. Brazelton Neonatal Behavioral Assessment Scale (NBAS) examinations were performed on each of the first 4 days of life. Nursing infants (n = 47) were grouped according to maternal PCA opioid in breast milk (meperidine [n = 24] or morphine [n = 23]); bottle-fed infants (n = 56) served as the control group. The three infant groups were equivalent with respect to initial characteristics and NBAS scores on the first 2 days of life. On the third day of life, infants in the morphine group were significantly more alert and oriented to animate human cues compared with infants in the meperidine or control group. On the fourth day of life, infants in the morphine group remained significantly more alert and oriented to animate human auditory cues than infants in the meperidine group. Average PCA opioid consumption through 48 h postpartum was equivalent (0.54 mg/kg morphine and 4.7 mg/kg meperidine); however, even with these small doses, meperidine was associated with significantly poorer neonatal alertness and orientation than morphine. Morphine is the PCA opioid of choice for postcesarean analgesia among nursing parturients. IMPLICATIONS: Among nursing parturients after cesarean delivery, intravenous patient-controlled analgesia with meperidine is associated with more neonatal neurobehavioral depression than patient-controlled analgesia with morphine. In this study, we found that nursing infants exposed to morphine were more alert and oriented to animate human cues than those exposed to meperidine.

The orientation of eosin-5-maleimide on human erythrocyte band 3 measured by fluorescence polarization microscopy.

The dominant motional mode for membrane proteins is uniaxial rotational diffusion about the membrane normal axis, and investigations of their rotational dynamics can yield insight into both the oligomeric state of the protein and its interactions with other proteins such as the cytoskeleton. However, results from the spectroscopic methods used to study these dynamics are dependent on the orientation of the probe relative to the axis of motion. We have employed polarized fluorescence confocal microscopy to measure the orientation of eosin-5-maleimide covalently reacted with Lys-430 of human erythrocyte band 3. Steady-state polarized fluorescence images showed distinct intensity patterns, which were fit to an orientation distribution of the eosin absorption and emission dipoles relative to the membrane normal axis. This orientation was found to be unchanged by trypsin treatment, which cleaves band 3 between the integral membrane domain and the cytoskeleton-attached domain. this result suggests that phosphorescence anisotropy changes observed after trypsin treatment are due to a rotational constraint change rather than a reorientation of eosin. By coupling time-resolved prompt fluorescence anisotropy with confocal microscopy, we calculated the expected amplitudes of the e-Dt and e-4Dt terms from the uniaxial rotational diffusion model and found that the e-4Dt term should dominate the anisotropy decay. Delayed fluorescence and phosphorescence anisotropy decays of control and trypsin-treated band 3 in ghosts, analyzed as multiple uniaxially rotating populations using the amplitudes predicted by confocal microscopy, were consistent with three motional species with uniaxial correlation times ranging from 7 microseconds to 1.4 ms.

Peptidoglycan hydrolases of Bacillus subtilis 168.

There are multiple peptidoglycan hydrolases associated with Bacillus subtilis 168 and these potentially lethal enzymes have been implicated in a number of important cellular processes. Several enzymes have been studied at the molecular level and their structural genes characterized. This information has begun to identify roles for individual enzymes in motility, cell separation, differentiation, and phage lysis. It has become apparent that in many cases important autolytic functions can be performed by more than one enzyme, so the complex web of mutually compensatory components can be unraveled only by making multiple mutants. One such multiple mutant has revealed the presence of several previously unknown minor autolysins, the functions of which are currently obscure.

Toxicology screening in adolescent trauma.

We sought to define the prevalence of positive drug screens in adolescent victims of major trauma. The records of 125 consecutive adolescent patients presenting with major trauma to an inner-city trauma center during the last nine months of 1990 were reviewed. Eighty-five (68%) received urine toxicology screens for alcohol and illicit drugs. Twenty-one (25%) of screened patients had a positive urine drug screen. The most commonly detected drugs were alcohol, cocaine, and opiates. Gender, race, mechanism of injury, mental status at presentation, injury severity score, and revised trauma score were not associated with a positive drug screen. We conclude that: 1) 25% of screened adolescent victims of major trauma seen at an inner-city trauma center had positive urine toxicology screens for alcohol or illicit drugs. 2) As none of the study variables was associated with a positive drug screen, selective drug screening cannot be supported.