Outcome Following Intramedullary Nailing of Tibial Diaphyseal Fractures: Suprapatellar Nail Insertion Results in Superior Radiographic Parameters But No Difference in Mid-Term Function

BACKGROUND

The primary aim of this study was to compare the radiographic parameters (nail insertion-point accuracy [NIPA] and fracture malalignment) of patients who had undergone tibial intramedullary nailing via the suprapatellar (SP) and infrapatellar (IP) approaches. The secondary aims were to compare clinical outcomes and patient-reported outcomes (PROs) between these approaches.

METHODS

All adult patients with an acute tibial diaphyseal fracture who underwent intramedullary nailing at a single level-I trauma center over a 4-year period (2017 to 2020) were retrospectively identified. The nailing approach (SP or IP) was at the treating surgeon's discretion. Intraoperative and immediate postoperative radiographs were reviewed to assess NIPA (mean distance from the optimal insertion point) and malalignment (≥5°). Medical records and radiographs were reviewed to evaluate the rates of malunion, nonunion, and other postoperative complications. The Oxford and Lysholm Knee Scores (OKS and LKS) and patient satisfaction (0 = completely dissatisfied, 100 = completely satisfied) were obtained via a postal survey at a minimum of 1 year postoperatively.

RESULTS

The cohort consisted of 219 consecutive patients (mean age, 48 years [range, 16 to 90 years], 51% [112] male). There were 61 patients (27.9%) in the SP group and 158 (72.1%) in the IP group. The groups did not differ in baseline demographic or injury-related variables. SP nailing was associated with superior coronal NIPA (p < 0.001; 95% confidence interval [CI] for IP versus SP, 1.17 to 3.60 mm) and sagittal NIPA (p < 0.001; 95% CI, 0.23 to 0.97 mm) and with a reduced rate of malalignment (3% [2 of 61] versus 11% [18 of 158] for IP; p = 0.030). PROs were available for 118 of 211 patients (56%; 32 of 58 in the SP group and 86 of 153 in the IP group) at a mean of 3 years (range, 1.2 to 6.5 years). There was no difference between the SP and IP groups in mean OKS (36.5 versus 39.6; p = 0.246), LKS (71.2 versus 73.5; p = 0.696), or satisfaction scores (81.4 versus 79.9; p = 0.725).

CONCLUSIONS

Compared with IP nailing, SP nailing of tibial shaft fractures was associated with superior NIPA and a reduced rate of intraoperative malalignment but not of malunion at healing. However, the superior NIPA may not be clinically important. Furthermore, there were no differences in PROs at mid-term follow-up.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Conserved plant transcriptional responses to microgravity from two consecutive spaceflight experiments

Introduction

Understanding how plants adapt to the space environment is essential, as plants will be a valuable component of long duration space missions. Several spaceflight experiments have focused on transcriptional profiling as a means of understanding plant adaptation to microgravity. However, there is limited overlap between results from different experiments. Differences in experimental conditions and hardware make it difficult to find a consistent response across experiments and to distinguish the primary effects of microgravity from other spaceflight effects.

Methods

Plant Signaling (PS) and Plant RNA Regulation (PRR) were two separate spaceflight experiments conducted on the International Space Station utilizing the European Modular Cultivation System (EMCS). The EMCS provided a lighted environment for plant growth with centrifugal capabilities providing an onboard 1 g control.

Results and discussion

An RNA-Seq analysis of shoot samples from PS and PRR revealed a significant overlap of genes differentially expressed in microgravity between the two experiments. Relative to onboard 1 g controls, genes involved in transcriptional regulation, shoot development, and response to auxin and light were upregulated in microgravity in both experiments. Conversely, genes involved in defense response, abiotic stress, Ca++ signaling, and cell wall modification were commonly downregulated in both datasets. The downregulation of stress responses in microgravity in these two experiments is interesting as these pathways have been previously observed as upregulated in spaceflight compared to ground controls. Similarly, we have observed many stress response genes to be upregulated in the 1 g onboard control compared to ground reference controls; however these genes were specifically downregulated in microgravity. In addition, we analyzed the sRNA landscape of the 1 g and microgravity (μ g) shoot samples from PRR. We identified three miRNAs (miR319c, miR398b, and miR8683) which were upregulated in microgravity, while several of their corresponding target genes were found to be downregulated in microgravity. Interestingly, the downregulated target genes are enriched in those encoding chloroplast-localized enzymes and proteins. These results uncover microgravity unique transcriptional changes and highlight the validity and importance of an onboard 1 g control.

Understanding Measurement of postural hypotension: a nationwide survey of primary care practice in England

BACKGROUND

Postural hypotension (PH), the drop in blood pressure (BP) on standing, is associated with falls, all-cause mortality and cognitive decline. PH diagnostic criteria require lying-to-standing BP measurements. PH Prevalence in older adults is 20%, however, it is infrequently recorded in primary care records, suggesting PH testing and/or recording is under-utilised in this setting.

AIM

To understand current PH measurement and management by primary care practitioners in England.

METHOD

Clinical Research Networks circulated an online survey to primary care clinicians involved in measurement of BP. Demographics and responses were summarised as percentages, or median and inter-quartile ranges (IQR), as appropriate. The survey remains open until 30 November 2022; full results will be presented at the conference.

RESULTS

To date, there are 669 replies (341 doctors, 179 nurses, 70 healthcare assistants, 23 pharmacists, 56 other roles); median age 45 (IQR 38 to 53), 72% female. Overall, 597 (89%) responders check for PH, predominantly when symptoms are present (98%). Less common reasons to check include patients being over 80 (24%), Parkinson's disease (21%), hypertension reviews (18%), medication reviews (12%) or diabetes reviews (11%). Sitting-to-standing BP measurements are common (77%); only 22% use lying-to-standing. Only 64% ensure a rest period before sitting or lying BP measurement and only 1 (IQR 1 to 2) standing BP measurement is made, usually (66%) within the first minute of standing.

CONCLUSION

Interim findings suggest that most PH assessments in primary care do not meet current guideline criteria. Full findings from this survey are expected to inform and influence future national guidelines.

Disparities in the excess risk of mortality in the first wave of COVID-19: Cross sectional study of the English sentinel network

OBJECTIVES

Few studies report contributors to the excess mortality in England during the first wave of coronavirus disease 2019 (COVID-19) infection. We report the absolute excess risk (AER) of mortality and excess mortality rate (EMR) from a nationally representative COVID-19 sentinel surveillance network including known COVID-19 risk factors in people aged 45 years and above.

METHODS

Pseudonymised, coded clinical data were uploaded from contributing primary care providers (N = 1,970,314, ≥45years). We calculated the AER in mortality by comparing mortality for weeks 2 to 20 this year with mortality data from the Office for National Statistics (ONS) from 2018 for the same weeks. We conducted univariate and multivariate analysis including preselected variables. We report AER and EMR, with 95% confidence intervals (95% CI).

RESULTS

The AER of mortality was 197.8/10,000 person years (95%CI:194.30-201.40). The EMR for male gender, compared with female, was 1.4 (95%CI:1.35-1.44, p<0.00); for our oldest age band (≥75 years) 10.09 (95%CI:9.46-10.75, p<0.00) compared to 45-64 year olds; Black ethnicity's EMR was 1.17 (95%CI: 1.03-1.33, p<0.02), reference white; and for dwellings with ≥9 occupants 8.01 (95%CI: 9.46-10.75, p<0.00). Presence of all included comorbidities significantly increased EMR. Ranked from lowest to highest these were: hypertension, chronic kidney disease, chronic respiratory and heart disease, and cancer or immunocompromised.

CONCLUSIONS

The absolute excess mortality was approximately 2 deaths per 100 person years in the first wave of COVID-19. More personalised shielding advice for any second wave should include ethnicity, comorbidity and household size as predictors of risk.

Health resource utilization of labor induction versus expectant management

BACKGROUND

Although induction of labor of low-risk nulliparous women at 39 weeks reduces the risk of cesarean delivery compared with expectant management, concern regarding more frequent use of labor induction remains, given that this intervention historically has been thought to incur greater resource utilization.

OBJECTIVE

The objective of the study was to determine whether planned elective labor induction at 39 weeks among low-risk nulliparous women, compared with expectant management, was associated with differences in health care resource utilization from the time of randomization through 8 weeks postpartum.

STUDY DESIGN

This is a planned secondary analysis of a multicenter randomized trial in which low-risk nulliparous women were assigned to induction of labor at 39 weeks or expectant management. We assessed resource utilization after randomization in 3 time periods: antepartum, delivery admission, and discharge through 8 weeks postpartum.

RESULTS

Of 6096 women with data available, those in the induction of labor group (n = 3059) were significantly less likely in the antepartum period after randomization to have at least 1 ambulatory visit for routine prenatal care (32.4% vs 68.4%), unanticipated care (0.5% vs 2.6%), or urgent care (16.2% vs 44.3%), or at least 1 antepartum hospitalization (0.8% vs 2.2%, P < .001 for all). They also had fewer tests (eg, sonograms, blood tests) and treatments (eg, antibiotics, intravenous hydration) prior to delivery. During the delivery admission, women in the induction of labor group spent a longer time in labor and delivery (median, 0.83 vs 0.57 days), but both women (P = .002) and their neonates (P < .001) had shorter postpartum stays. Women and neonates in both groups had similar frequencies of postpartum urgent care and hospital readmissions (P > .05 for all).

CONCLUSION

Women randomized to induction of labor had longer durations in labor and delivery but significantly fewer antepartum visits, tests, and treatments and shorter maternal and neonatal hospital durations after delivery. These results demonstrate that the health outcome advantages associated with induction of labor are gained without incurring uniformly greater health care resource use.

P2649Do these data apply to me? Examining the applicability of trials assessing strategies for optimal management of blood pressure to older patients in UK primary care

Background

There is debate as to what extent older patients (≥80 years) should be treated for high blood pressure. Existing trials show that blood pressure lowering in this population is effective at preventing stroke and heart failure but also results in an increased risk of adverse events. However, it has been suggested that these studies enrolled healthier patients, who are less representative of the general population and more likely to benefit from treatment.

Purpose

This study aimed to compare the characteristics of patients eligible for three blood pressure management trials and assess the likelihood of eligibility for each trial based on common characteristics of older patients.

Methods

Cross-sectional study of data extracted from the medical records of 15,376 patients aged ≥80 years, registered to 24 general practices in the south of England. Anonymised patient data relating to the eligibility criteria for two previous medication intensification trials (HYVET, SPRINT) and one medication reduction trial (OPTiMISE) were extracted. Patients eligible for each trial were defined according to criteria specified in each trial protocol. Descriptive statistics were used to define the characteristics of each trial population. A logistic regression model was constructed to estimate predictors of eligibility for each trial, with practice included as a random effect.

Results

Approximately 268 (1.7%), 5,290 (34.4%) and 3,940 (25.6%) patients were eligible for HYVET, SPRINT and OPTiMISE trials respectively. There was little overlap in eligibility for each trial (1.0% were eligible for HYVET and SPRINT; 0% were eligible for HYVET and OPTiMISE; 10.2% were eligible for SPRINT and OPTiMISE). Patients eligible for OPTiMISE were comparable to the general population in terms of frailty (eFI 0.12 [OPTiMISE] vs 0.11 [general population]), but had more morbidities (4 vs 3) and cardiovascular medications prescribed (4 vs 2). Patients in HYVET and SPRINT were less frail, multi-morbid and prescribed less cardiovascular medications. Overall, increasing frailty and a history of cardiovascular disease reduced the likelihood of being eligible for any trial.

Conclusions

Patients eligible for OPTiMISE appear to best represent the population aged ≥80 years attending UK primary care. Increasing frailty and/or multi-morbidity reduce the likelihood of eligibility for all three blood pressure trials. Caution should be exercised when applying the results from randomised controlled trials to management of blood pressure in frail and multi-morbid patients.

Acknowledgement/Funding

This study was funded by the National Institute for Health Research (NIHR) SPCR and Oxford CLAHRC

Movement-based estimation and visualization of space use in 3D for wildlife ecology and conservation

Advances in digital biotelemetry technologies are enabling the collection of bigger and more accurate data on the movements of free-ranging wildlife in space and time. Although many biotelemetry devices record 3D location data with x, y, and z coordinates from tracked animals, the third z coordinate is typically not integrated into studies of animal spatial use. Disregarding the vertical component may seriously limit understanding of animal habitat use and niche separation. We present novel movement-based kernel density estimators and computer visualization tools for generating and exploring 3D home ranges based on location data. We use case studies of three wildlife species – giant panda, dugong, and California condor – to demonstrate the ecological insights and conservation management benefits provided by 3D home range estimation and visualization for terrestrial, aquatic, and avian wildlife research.

Health-seeking behaviour for schistosomiasis: a systematic review of qualitative and quantitative literature

Schistosomiasis is a chronic and debilitating parasitic disease acquired through contact with infested freshwater. An essential component of its control is passive case finding, which, in order to be effective, requires a detailed understanding of health-seeking behaviour. This study aimed to systematically review evidence on health-seeking behaviour for schistosomiasis, in order to determine factors influencing use or non-use of modern health services for the infection. Quantitative, qualitative and mixed method studies reporting on factors related to seeking treatment from modern health services for schistosomiasis were obtained, combining electronic and hand searching. Data extraction and quality assessment of the included articles were performed, with all studies qualitatively analysed using thematic synthesis. A total of 19 studies were included in the review. Six themes were identified from the analysis: biomedical knowledge on schistosomiasis, perceptions of modern treatment and health services, financial considerations of treatment, perceptions on the symptoms, stigma of the infection, and physical location and community. These findings were consistent across studies of different design, setting and quality. Many of the themes identified echo existing literature on health-seeking behaviour. The synthesis also highlighted the role of stigma, and aspects of the physical location and community that may affect treatment-seeking for schistosomiasis. Health education programmes that intend to improve the utilisation of modern health services for the infection need to acknowledge the multiple determinants influencing their use. Future research should move beyond describing health-seeking behaviour to identifying the factors that underlay such behaviour.

Informing species conservation at multiple scales using data collected for marine mammal stock assessments

BACKGROUND

Conservation planning and the design of marine protected areas (MPAs) requires spatially explicit information on the distribution of ecological features. Most species of marine mammals range over large areas and across multiple planning regions. The spatial distributions of marine mammals are difficult to predict using habitat modelling at ecological scales because of insufficient understanding of their habitat needs, however, relevant information may be available from surveys conducted to inform mandatory stock assessments.

METHODOLOGY AND RESULTS

We use a 20-year time series of systematic aerial surveys of dugong (Dugong dugong) abundance to create spatially-explicit models of dugong distribution and relative density at the scale of the coastal waters of northeast Australia (∼136,000 km(2)). We interpolated the corrected data at the scale of 2 km * 2 km planning units using geostatistics. Planning units were classified as low, medium, high and very high dugong density on the basis of the relative density of dugongs estimated from the models and a frequency analysis. Torres Strait was identified as the most significant dugong habitat in northeast Australia and the most globally significant habitat known for any member of the Order Sirenia. The models are used by local, State and Federal agencies to inform management decisions related to the Indigenous harvest of dugongs, gill-net fisheries and Australia's National Representative System of Marine Protected Areas.

CONCLUSION/SIGNIFICANCE

In this paper we demonstrate that spatially-explicit population models add value to data collected for stock assessments, provide a robust alternative to predictive habitat distribution models, and inform species conservation at multiple scales.

Simple sequence repeat markers associated with three quantitative trait loci for black point resistance can be used to enrich selection populations in bread wheat

Black point in wheat has the potential to cost the Australian industry $A30.4 million a year. It is difficult and expensive to screen for resistance, so the aim of this study was to validate 3 previously identified quantitative trait loci (QTLs) for black point resistance on chromosomes 2B, 4A, and 3D of the wheat variety Sunco. Black point resistance data and simple sequence repeat (SSR) markers, linked to the resistance QTLs and suited to high-throughput assay, were analysed in the doubled haploid population, Batavia (susceptible) × Pelsart (resistant). Sunco and Pelsart both have Cook in their pedigree and both have the Triticum timopheevii translocation on 2B. SSR markers identified for the 3 genetic regions were gwm319 (2B, T. timopheevii translocation), wmc048 (4AS), and gwm341 (3DS). Gwm319 and wmc048 were associated with black point resistance in the validation population. Gwm341 may have an epistatic influence on the trait because when resistance alleles were present at both gwm319 and wmc048, the Batavia-derived allele at gwm341 was associated with a higher proportion of resistant lines. Data are presented showing the level of enrichment achieved for black point resistance, using 1, 2, or 3 of these molecular markers, and the number of associated discarded resistant lines. The level of population enrichment was found to be 1.83-fold with 6 of 17 resistant lines discarded when gwm319 and wmc048 were both used for selection. Interactions among the 3 QTLs appear complex and other genetic and epigenetic factors influence susceptibility to black point. Polymorphism was assessed for these markers within potential breeding material. This indicated that alternative markers to wmc048 may be required for some parental combinations. Based on these results, marker-assisted selection for the major black point resistance QTLs can increase the rate of genetic gain by improving the selection efficiency and may facilitate stacking of black point resistances from different sources.

Cellular immunity in salmonids infected with the microsporidial parasite Loma salmonae or exposed to non-viable spores

Following a per os challenge of naive rainbow trout with live spores of Loma salmonae, head kidney mononuclear cells (MNC) in culture were able to proliferate in response to crude soluble parasite extract or intact dead spores. A significant response was seen by week 2 post-exposure and a maximum response developed by week 6 or 8, respectively. During this initial challenge, spore filled cysts developed on the gills of challenged fish, and the cysts ruptured by week 12 as is typical for microsporidial gill disease of salmonids (MGDS). Two weeks following this, fish were re-challenged with live spores, and in these fish an enhanced in vitro proliferative response of MNC was immediately apparent, and spore filled cysts did not develop. In contrast, when naive trout were given dead spores by intraperitoneal injection, the most pronounced proliferative responses of MNC developed earlier (week 2 PE) and the response was greater when cells were incubated in vitro with dead spores rather than with crude soluble extract. When these fish were re-challenged per os with live spores, a heightened proliferation in MNC was observed 4 weeks after this exposure and the fish likewise resisted development of xenomas. In fish infected orally or injected intraperitoneally with spores, a marked increase in the response to the mitogen concanavalin A was seen for 22 weeks post-exposure when compared to controls not receiving any spores.

Observation of structural anisotropy and the onset of liquidlike motion during the nonthermal melting of InSb

The melting dynamics of laser excited InSb have been studied with femtosecond x-ray diffraction. These measurements observe the delayed onset of diffusive atomic motion, signaling the appearance of liquidlike dynamics. They also demonstrate that the root-mean-squared displacement in the [111] direction increases faster than in the [110] direction after the first 500 fs. This structural anisotropy indicates that the initially generated fluid differs significantly from the equilibrium liquid.

Direct observation of the alpha-epsilon transition in shock-compressed iron via nanosecond x-ray diffraction

In situ x-ray diffraction studies of iron under shock conditions confirm unambiguously a phase change from the bcc (alpha) to hcp (epsilon) structure. Previous identification of this transition in shock-loaded iron has been inferred from the correlation between shock-wave-profile analyses and static high-pressure x-ray measurements. This correlation is intrinsically limited because dynamic loading can markedly affect the structural modifications of solids. The in situ measurements are consistent with a uniaxial collapse along the [001] direction and shuffling of alternate (110) planes of atoms, and are in good agreement with large-scale nonequilibrium molecular dynamics simulations.

Atomic-Scale Visualization of Inertial Dynamics

The motion of atoms on interatomic potential energy surfaces is fundamental to the dynamics of liquids and solids. An accelerator-based source of femtosecond x-ray pulses allowed us to follow directly atomic displacements on an optically modified energy landscape, leading eventually to the transition from crystalline solid to disordered liquid. We show that, to first order in time, the dynamics are inertial, and we place constraints on the shape and curvature of the transition-state potential energy surface. Our measurements point toward analogies between this nonequilibrium phase transition and the short-time dynamics intrinsic to equilibrium liquids.

Clocking femtosecond X rays

Linear-accelerator-based sources will revolutionize ultrafast x-ray science due to their unprecedented brightness and short pulse duration. However, time-resolved studies at the resolution of the x-ray pulse duration are hampered by the inability to precisely synchronize an external laser to the accelerator. At the Sub-Picosecond Pulse Source at the Stanford Linear-Accelerator Center we solved this problem by measuring the arrival time of each high energy electron bunch with electro-optic sampling. This measurement indirectly determined the arrival time of each x-ray pulse relative to an external pump laser pulse with a time resolution of better than 60 fs rms.

Australian wheat for the sponge and dough bread making process

This work investigates the suitability of Australian wheats for the sponge and dough bread market, and determines the wheat quality attributes most important for large loaf volume. A group of 30 genotypes was selected for quality testing and baking using a purpose-developed sponge and dough test baking method. Genotypes were grown at 2 sites in Queensland during winter of 2001 and 2002, and then grain from the field trials was tested in the laboratory. The traits measured included grain, flour, and dough quality, along with loaf volume as the main trait of interest. Glutenin alleles and Wx-B1 allele status of the genotypes were also determined. Genetic correlations were calculated between loaf volume and all the quality traits. The quality trait with the strongest relationship to loaf volume was flour swelling volume. Glutenin alleles and Wx-B1 alleles may also be important for sponge and dough bread quality but the data presented here were insufficient to draw strong conclusions. Consistent, large sponge and dough loaf volumes (>850 cm3) were achieved by the Batavia/Pelsart double haploids QT8753, QT10793, and QT10778. The wheat varieties Hartog and Kennedy also performed well. The work demonstrated that Australia can produce wheat suitable for this market.

Mannitol in cardioplegia as an oxygen free radical scavenger measured by malondialdehyde

Oxygen free radicals (OFRs) are associated with ischaemia-reperfusion injury involving many organs, including the heart, which can lead to depressed cardiac function and abnormalities in the cardiac ultrastructure. This is seen upon the release of the aortic crossclamp when the ischaemic myocardium is reperfused in patients undergoing cardiopulmonary bypass (CPB). Various studies have shown that by adding OFR scavenging agents or antioxidants to the CPB prime or cardioplegia, cardiac performance improves. Mannitol is an osmotic diuretic with free radical scavenging properties, which has been shown to reduce the extent of ischaemic injury and improve the function of the myocardium. This study evaluated how effective mannitol is as an OFR scavenger by administering different concentrations of cardioplegia antegrade into the aortic root, thus maximising its effects directly upon the myocardium rather than being diluted in the CPB prime. Thirty-three patients undergoing primary coronary artery bypass grafting (CABG) were, by double blind random selection, allocated into one of three groups: group 1, a control group (consisting of 11 patients) receiving no mannitol; group 2 (11 patients), receiving a concentration of 4 g/l; and group 3 (11 patients), receiving 8 g/l. Three blood samples were taken directly from the coronary sinus during bypass: the first sample at the start of bypass, just prior to the crossclamp being applied; the second sample just after removal of the crossclamp; and the third sample just prior to termination of bypass. All samples were then centrifuged and the plasma analysed for malondialdehyde (MDA) using high-performance liquid chromatography (HPLC). MDA, an endproduct of lipid peroxidation, causes cellular damage and disruption of cell membranes when tissue antioxidants are exhausted. The more MDA produced, the greater the depletion of tissue antioxidants secondary to OR formation during reperfusion when the aortic crossclamp is removed. HPLC is a useful biochemical study; however, it is not a direct indicator of depressed myocardial function, such as an invasive test would be, and this should be borne in mind. Statistically, the results do not show a significant difference among the three groups or among the three samples. However, a trend can be seen, which shows lower levels of MDA in the two groups receiving mannitol and there is an indication of a rise in MDA levels upon the start of reperfusion in the two groups receiving mannitol, but not the control group. It is concluded that further samples would be needed to find a significant difference in MDA concentrations.

Use of conductivity to monitor the treatment of acid mine drainage by sulphate-reducing bacteria

Measurements of electrical conductivity were obtained during treatment of acid mine drainage (AMD) by sulphate-reducing bacteria (SRB) in fed-batch column reactors. The advantages of this method are that it is non-invasive, non-destructive, and rapid, giving real-time information. Conductivity measurements were taken on an hourly basis throughout the course of several experiments in which the SRB were exposed to different quantities of fresh AMD. Simultaneous measurements were taken in a column in which no SRB were present but were also exposed to the same volumes of fresh AMD. As treatment of the AMD progressed, increases in conductivity were measured, generally localized to two regions in the gravel bed: the top and bottom 10 cm (4"). Changes in conductivity were not always coincident with changes in ORP and pH, indicating that conductivity may be a more sensitive tool for locating and monitoring specific zones of SRB activity.

Complacent and conflicting scientific expertise in British and American drug regulation: clinical risk assessment of triazolam

This paper presents a case study in the production and interpretation of regulatory science, focusing on the conflicting British and American clinical risk assessments of triazolam (Halcion) - the most controversial sleeping pill in the world. The regulation of triazolam is shown to be more permissive in the USA than in the UK. Six principal socio-political factors are put forward to explain this; differential regulatory trust; regulators' socio-technical data selections; medico-scientific disciplinary influences; organizational and professional interests; conflicts of interest of expert advisers; and the growth of the neo-liberal regulatory state. The risk assessments of both the British and American regulatory agencies are shown to be complacent relative to technical standards which the agencies themselves later accepted. It is suggested that, when the interests of pharmaceutical manufacturers and patients diverge, regulatory assessments are crucially affected by whether regulators are predisposed to award the benefit of the scientific doubts to the manufacturers or patients, and by the balance of such predispositions both within and between regulatory institutions of scientific expertise. The triazolam case indicates that the amount of trust placed in the pharmaceutical industry by the British American regulatory systems may hamper detection of flaws in manufacturers' medical data in a timely manner and, as a consequence, compromise patients' interests. Some policy implications for drug regulation are sketched.

The clinical task

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Latrine ownership as a protective factor in inflammatory trachoma in Egypt

We investigated the association between inflammatory trachoma in children aged 1-5 and environmental and sociodemographic risk factors in a rural Nile Delta hamlet. Inflammatory trachoma clustered in households, emphasising the child-to-child nature of transmission in the hamlet. Multiple logistic regression analysis revealed three factors predicting inflammatory trachoma in children: the absence of a latrine in the household, school-age siblings with inflammatory trachoma, and additional same-age siblings (with or without disease) in the household. In the Egyptian setting the presence of pit latrines in all houses, even when full and unscreened, might result in a reduction in trachoma prevalence in this population from the current 49% to 35%. The construction of pit latrines may offer the simplest and most acceptable environmental method for reducing trachoma in this trachoma endemic area.

Trachoma and blindness in the Nile Delta: current patterns and projections for the future in the rural Egyptian population

A population based survey of trachoma and blindness was conducted in a rural Nile Delta hamlet. Trachoma remains hyperendemic in this region. Active trachoma was common among preschool children; over half had moderate to severe disease. Of residents 25 years old 90% had substantial conjunctival scarring. Severe conjunctival scarring was commoner among women (84%) than men (58%), and three-quarters of older women had trichiasis/entropion compared with 57% of older men. Males and females had equivalent age specific rates of inflammatory disease. Blindness was associated with old age; 17% of residents aged 50 and over were blind. Estimates of blindness based on this survey and other surveys in Egypt indicate that blindness is still a serious public health problem in rural Egypt. The number of blind persons in Egypt will increase from an estimated 420,000 in 1980 to 868,000 by the year 2020. The current crude blindness rate of 1.8% is expected to increase to 2.3% in the year 2000 and to 3.2% in 2020.

Nonculture methods for diagnosing chlamydial infection in patients with trachoma: a clue to the pathogenesis of the disease?

We studied five different tests for diagnosing conjunctival Chlamydia trachomatis infection in specimens obtained from 100 children with moderate-to-severe trachoma. The tests were Giemsa stain, isolation in cell culture, direct fluorescein-conjugated monoclonal antibody, enzyme immunoassay, and a DNA probe. The Giemsa stain was least sensitive at 29%. The other tests gave essentially equivalent performances: sensitivity ranged from 73% to 84% and specificity from 93% to 100%. Seven of the 45 positive specimens were only positive in cell culture, whereas 11 of the 45 were negative in culture but positive in at least two nonculture tests. We speculate that these discordant results actually reflect the biologic status of the chlamydial infection. There appears to be a stage in the infection where chlamydial antigens and nucleic acids can be detected in the absence of infectivity. This stage of infection may contribute to the pathogenesis of trachoma by providing a source of sensitizing antigen.

Closed complex dorsal dislocation of the middle finger metacarpophalangeal joint: anatomic considerations and treatment

A rare complex isolated metacarpophalangeal joint dislocation of the middle finger is described, and the pathology is reviewed. The dorsal longitudinal incision used in this case provided excellent exposure for the reduction and helped avoid injury to the digital nerves on the palmar side of the injury. Early mobilization with extension blocking is advocated to maximize joint range of motion postoperatively.

Reconstitution of the Gs protein from B16 melanoma clones of high and low experimental metastatic potential into S49 cyc-membranes

The ability of a series of B16 melanoma clones to form experimental lung metastases in syngeneic mice has been shown to correlate positively with adenylate cyclase activity. (Sheppard et al, Int. J. Cancer 37 (1986) 713-722). To begin to identify the components of the adenylate cyclase complex that account for enhanced enzyme activity in highly metastatic tumor populations, cholate extracts containing the GTP-binding protein GS from B16 melanoma clones of different metastatic capacities were reconstituted with membranes prepared from S49 cyc-, a variant lymphoma cell line that lacks GS function. The results revealed that extracts from a highly metastatic B16 clone (F10-C23) reconstituted significantly greater adenylate cyclase activities in S49 cyc- membranes than parallel preparations from a B16 clone (F1-C29) of low metastatic capacity. The data suggest that aberrations in GS function may contribute to the heightened responsiveness of adenylate cyclase observed in B16 melanoma clones of increased metastatic potential.

Aminocaproic acid reduces the risk of secondary hemorrhage in patients with traumatic hyphema

In a prospective, randomized, double-masked study, 34 patients (34 eyes) with nonperforating ocular injury and traumatic hyphema were treated with either aminocaproic acid (Amicar), 100 mg/kg every four hours, up to a maximum of 30 g/d, or placebo for five days. None of 21 patients who were treated with aminocaproic acid rebled, while three (23%) of 13 patients who were treated with placebo rebled. This difference was statistically significant. Of the three patients who rebled, two required surgical intervention, with one patient requiring four surgical procedures. Although complications following aminocaproic acid therapy included light-headedness, nausea and vomiting, and systemic hypotension, only one patient was withdrawn from the study because of drug-related adverse reactions. This study strongly confirms that aminocaproic acid therapy significantly reduces the incidence of secondary hemorrhage following traumatic hyphema.

2'-nor-cGMP, a new cyclic derivative of 2'NDG, inhibits HSV-1 replication in vitro and in the mouse keratitis model

The present study examined the antiherpetic effect of 2'-nor-cGMP, a new cyclic phosphate derivative of 2'NDG, in vitro and in the mouse keratitis model. The 50% inhibitory dose (ID50) was determined with HSV-1 RE strain in Vero cell monolayers for 2'-nor-cGMP (6.9 mcg./ml), 2'NDG (.06 mcg/ml), and trifluridine (F3T) (.72 mcg/ml). Balb C mice underwent bilateral ocular inoculation with HSV-1 RE strain, and then were treated with different therapeutic regimens. The antiviral efficacy of each drug was evaluated by ocular virus titers, clinical grading of epithelial keratitis, and histological evaluation of stromal keratitis. 2'-nor-cGMP was the most effective drug (P = .0001) in reducing ocular viral titers. Both 2'-nor-cGMP and 2'NDG were significantly more effective (P = .0001) than F3T in reducing epithelial keratitis, and as effective as F3T in reducing stromal keratitis.