Initial Clinical Laboratory Response to COVID-19: A Qualitative Lookback at a Survey of Medical Laboratory Professionals

Introduction/Objective

In this 2020 survey, the co-investigators of this study explored the experiences of medical laboratory professionals (MLPs) and their perceptions of the testing needs of clinical laboratories in the initial response to the COVID-19 pandemic. The responses gathered in this survey highlighted changes in the laboratory workforce and the impact on laboratory operations moving forward.

Methods/Case Report

This cross-sectional, anonymous, web-based survey of MLPs was conducted between April 29, 2020, and May 31, 2020. To recruit participants, ‘invitation to participate’ messages were posted using online forums and social media platforms (i.e. LinkedIn, Twitter). Furthermore, the survey link was shared with professional contacts and laboratory professional groups. The main source of recruitment was the membership of the American Society for Clinical Laboratory Science (ASCLS), which had more than 6,800 active members at the time of the study. Data provided from individuals who provided informed consent was included in the sample. The inclusion criteria for the survey were that participants self-identify as a current employee of a clinical laboratory whose usual employment involved participating in the diagnostic testing and providing of clinical laboratory test results using human specimens. The instrument gathered demographic data about participants and their workplace using 32 closed-ended questions with 8 questions containing branching that allowed for optional open-ended responses. This project was approved by the institutional review board at the University of Kansas Medical Center.

Results (if a Case Study enter NA)

Notably, there was an overall decrease in clinical laboratory testing and overtime work for laboratorians during the first months of the COVID-19 pandemic. Respondents noted a lack of pay increase during the pandemic; however, some received in-kind gifts and messages of support in recognition of their essential work. MLPs reported better (or unchanged) job satisfaction and morale in their respective workplaces.

Conclusion

The response to the testing needs by healthcare facilities and clinical laboratory leadership can influence the job satisfaction of MLPs, perceptions toward their work, and overall morale during the initial phase of the pandemic. Additionally, cost-reducing measures further shaped the perceptions of MLPs while impacting the operational efficiency of clinical laboratories.

Direct gas-in-place measurements prove much higher production potential than expected for shale formations

Shale gas exploitation has been the game-changer in energy development of the past decade. However, the existing methods of estimating gas in place in deep formations suffer from large uncertainties. Here, we demonstrate, by using novel high-pressure experimental techniques, that the gas in place within deep shale gas reservoirs can be up to five times higher than that estimated by implementing industry standard approaches. We show that the error between our laboratory approach and the standard desorption test is higher for gases with heavier compositions, which are of strongest commercial interests. The proposed instrumentation is reliable for deep formations and, provides quick assessment of the potential for the gas in place, which could be useful for assessing hydrocarbon reservoirs, and the potential for geological carbon sequestration of a given formation.

Diamond-Graphene Composite Nanostructures

The search for new nanostructural topologies composed of elemental carbon is driven by technological opportunities as well as the need to understand the structure and evolution of carbon materials formed by planetary shock impact events and in laboratory syntheses. We describe two new families of diamond-graphene (diaphite) phases constructed from layered and bonded sp³ and sp² nanostructural units and provide a framework for classifying the members of this new class of materials. The nanocomposite structures are identified within both natural impact diamonds and laboratory-shocked samples and possess diffraction features that have previously been assigned to lonsdaleite and postgraphite phases. The diaphite nanocomposites represent a new class of high-performance carbon materials that are predicted to combine the superhard qualities of diamond with high fracture toughness and ductility enabled by the graphitic units and the atomically defined interfaces between the sp³- and sp²-bonded nanodomains.

Quantifying hexagonal stacking in diamond

Diamond is a material of immense technological importance and an ancient signifier for wealth and societal status. In geology, diamond forms as part of the deep carbon cycle and typically displays a highly ordered cubic crystal structure. Impact diamonds, however, often exhibit structural disorder in the form of complex combinations of cubic and hexagonal stacking motifs. The structural characterization of such diamonds remains a challenge. Here, impact diamonds from the Popigai crater were characterized with a range of techniques. Using the MCDIFFaX approach for analysing X-ray diffraction data, hexagonality indices up to 40% were found. The effects of increasing amounts of hexagonal stacking on the Raman spectra of diamond were investigated computationally and found to be in excellent agreement with trends in the experimental spectra. Electron microscopy revealed nanoscale twinning within the cubic diamond structure. Our analyses lead us to propose a systematic protocol for assigning specific hexagonality attributes to the mineral designated as lonsdaleite among natural and synthetic samples.

A randomized controlled trial protocol assessing the effectiveness, safety and cost-effectiveness of methotrexate vs. ciclosporin in the treatment of severe atopic eczema in children: the TREatment of severe Atopic eczema Trial (TREAT)

BACKGROUND

Oral systemic immunomodulatory medication is regularly used off-licence in children with severe atopic eczema. However, there is no firm evidence regarding the effectiveness, safety, cost-effectiveness and impact on quality of life from an adequately powered randomized controlled trial (RCT) using systemic medication in children.

OBJECTIVES

To assess whether there is a difference in the speed of onset, effectiveness, side-effect profile and reduction in flares post-treatment between ciclosporin (CyA) and methotrexate (MTX), and also the cost-effectiveness of the drugs. Treatment impact on quality of life will also be examined in addition to whether FLG genotype influences treatment response. In addition, the trial studies the immune-metabolic effects of CyA and MTX.

METHODS

Multicentre, parallel group, assessor-blind, pragmatic RCT of 36 weeks' duration with a 24-week follow-up period. In total, 102 children aged 2-16 years with moderate-to-severe atopic eczema, unresponsive to topical treatment will be randomized (1 : 1) to receive MTX (0·4 mg kg^-1 per week) or CyA (4 mg kg^-1 per day).

RESULTS

The trial has two primary outcomes: change from baseline to 12 weeks in Objective Severity Scoring of Atopic Dermatitis (o-SCORAD) and time to first significant flare following treatment cessation.

CONCLUSIONS

This trial addresses important therapeutic questions, highlighted in systematic reviews and treatment guidelines for atopic eczema. The trial design is pragmatic to reflect current clinical practice.

Circulating immune cells in multiple sclerosis

Circulating T and B lymphocytes contribute to the pathogenesis of the neuroinflammatory autoimmune disease, multiple sclerosis (MS). Further progress in the development of MS treatments is dependent upon a greater understanding of the immunological disturbances that underlie the disease. Analyses of circulating immune cells by flow cytometry have revealed MS-associated alterations in the composition and function of T and B cell subsets, including temporal changes associated with disease activity. Disturbances in circulating immune populations reflect those observed in the central nervous system and include skewing towards proinflammatory CD4⁺ and CD8⁺ T cells and B cells, greater proportions of follicular T helper cells and functional defects in the corresponding T and B regulatory subsets. Utilizing the analytical power of modern flow cytometers, researchers are now well positioned to monitor immunological changes associated with disease activity or intervention, describe immunological signatures with predictive value and identify targets for therapeutic drug development. This review discusses the contribution of various T and B lymphocyte subsets to MS pathogenesis, provides current and relevant phenotypical descriptions to assist in experimental design and highlights areas of future research.

Organic Matter Responses to Radiation under Lunar Conditions

Large bodies, such as the Moon, that have remained relatively unaltered for long periods of time have the potential to preserve a record of organic chemical processes from early in the history of the Solar System. A record of volatiles and impactors may be preserved in buried lunar regolith layers that have been capped by protective lava flows. Of particular interest is the possible preservation of prebiotic organic materials delivered by ejected fragments of other bodies, including those originating from the surface of early Earth. Lava flow layers would shield the underlying regolith and any carbon-bearing materials within them from most of the effects of space weathering, but the encapsulated organic materials would still be subject to irradiation before they were buried by regolith formation and capped with lava. We have performed a study to simulate the effects of solar radiation on a variety of organic materials mixed with lunar and meteorite analog substrates. A fluence of ∼3 × 10¹³ protons cm^-2 at 4-13 MeV, intended to be representative of solar energetic particles, has little detectable effect on low-molecular-weight (≤C₃₀) hydrocarbon structures that can be used to indicate biological activity (biomarkers) or the high-molecular-weight hydrocarbon polymer poly(styrene-co-divinylbenzene), and has little apparent effect on a selection of amino acids (≤C₉). Inevitably, more lengthy durations of exposure to solar energetic particles may have more deleterious effects, and rapid burial and encapsulation will always be more favorable to organic preservation. Our data indicate that biomarker compounds that may be used to infer biological activity on their parent planet can be relatively resistant to the effects of radiation and may have a high preservation potential in paleoregolith layers on the Moon. Key Words: Radiation-Moon-Regolith-Amino acids-Biomarkers. Astrobiology 16, 900-912.

The Moon as a recorder of organic evolution in the early solar system: a lunar regolith analog study

The organic record of Earth older than ∼3.8 Ga has been effectively erased. Some insight is provided to us by meteorites as well as remote and direct observations of asteroids and comets left over from the formation of the Solar System. These primitive objects provide a record of early chemical evolution and a sample of material that has been delivered to Earth's surface throughout the past 4.5 billion years. Yet an effective chronicle of organic evolution on all Solar System objects, including that on planetary surfaces, is more difficult to find. Fortunately, early Earth would not have been the only recipient of organic matter-containing objects in the early Solar System. For example, a recently proposed model suggests the possibility that volatiles, including organic material, remain archived in buried paleoregolith deposits intercalated with lava flows on the Moon. Where asteroids and comets allow the study of processes before planet formation, the lunar record could extend that chronicle to early biological evolution on the planets. In this study, we use selected free and polymeric organic materials to assess the hypothesis that organic matter can survive the effects of heating in the lunar regolith by overlying lava flows. Results indicate that the presence of lunar regolith simulant appears to promote polymerization and, therefore, preservation of organic matter. Once polymerized, the mineral-hosted newly formed organic network is relatively protected from further thermal degradation. Our findings reveal the thermal conditions under which preservation of organic matter on the Moon is viable.

A longitudinal study of the distance that young people walk to school

Walking or cycling to school has been associated with important health benefits. Distance between home and school is the main correlate of active commuting to school, but how far children walk to school and how this changes as children age is unknown. Mode of commuting and objectively-assessed distance to school were measured at 3 time points: aged 9/10 years, 10/11 years and 13/14 years. Data were analysed using ROC-curve analyses. With age, children walked further to school; the threshold distance that best discriminated walkers from passive commuters was 1421 m in 10-year-olds, 1627 m in 11-year-olds and 3046 m in 14-year-olds. Future interventions should consider the distance that young people actually walk.

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The distance walked to school changes when children age.

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The threshold distance that best discriminates walkers and passive commuters is 1.4 km for 10 years children and 3 km for 14 years adolescents.

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These threshold distances will help inform policy, practice and future intervention efforts.

The influence of geographical access to health care and material deprivation on colorectal cancer survival: evidence from France and England

This article investigates the influence of distance to health care and material deprivation on cancer survival for patients diagnosed with a colorectal cancer between 1997 and 2004 in France and England. This population-based study included all cases of colorectal cancer diagnosed between 1997 and 2004 in 3 cancer registries in France and 1 cancer registry in England (N=40,613). After adjustment for material deprivation, travel times in England were no longer significantly associated with survival. In France patients living between 20 and 90min from the nearest cancer unit tended to have a poorer survival, although this was not statistically significant. In England, the better prognosis observed for remote patients can be explained by associations with material deprivation; distance to health services alone did not affect survival whilst material deprivation level had a major influence, with lower survival for patients living in deprived areas. Increases in travel times to health services in France were associated with poorer survival rates. The pattern of this influence seems to follow an inverse U distribution, i.e. maximal for average travel times.

Review of emergency department wound management in soft tissue trauma - is there a plan?

OBJECTIVE

To assess current acute wound management in English emergency departments.

METHOD

All English emergency departments including minor injury units (n=207) were successfully contacted and a telephone questionnaire was completed. This considered wound treatment policy; management including cleansing, analgesia, dressing selection, suturing, referral patterns, medical photography and antibiotic use.

RESULTS

There was a 100% response. Only 40% of departments had a wound treatment policy. Most had implemented staff training, however the nature and timing of this was variable. Wound cleansing was performed by all departments. Most administered analgesia. Suturing was selectively performed by all departments. There was great diversity regarding dressing selection. The most common reasons for referral to specialist units were the complexity of injury and cosmetically sensitive areas. Photographs were regularly taken in one third of units questioned.

CONCLUSION

This study confirmed an absence of a standard protocol for early soft tissue wound management in the emergency department setting. Key areas that could be improved are dressing simplification, more defined referral criteria and introduction of standardised protocols with structured teaching programmes. We propose a simple approach to management of acute soft tissue wounds that can be applied to most situations.

DECLARATION OF INTEREST

There were no external sources of funding for this study. The authors have no conflicts of interest to declare.

Melatonin for sleep problems in children with neurodevelopmental disorders: randomised double masked placebo controlled trial

OBJECTIVE

To assess the effectiveness and safety of melatonin in treating severe sleep problems in children with neurodevelopmental disorders.

DESIGN

12 week double masked randomised placebo controlled phase III trial.

SETTING

19 hospitals across England and Wales.

PARTICIPANTS

146 children aged 3 years to 15 years 8 months were randomised. They had a range of neurological and developmental disorders and a severe sleep problem that had not responded to a standardised sleep behaviour advice booklet provided to parents four to six weeks before randomisation. A sleep problem was defined as the child not falling asleep within one hour of lights out or having less than six hours' continuous sleep.

INTERVENTIONS

Immediate release melatonin or matching placebo capsules administered 45 minutes before the child's bedtime for a period of 12 weeks. All children started with a 0.5 mg capsule, which was increased through 2 mg, 6 mg, and 12 mg depending on their response to treatment.

MAIN OUTCOME MEASURES

Total sleep time at night after 12 weeks adjusted for baseline recorded in sleep diaries completed by the parent. Secondary outcomes included sleep onset latency, assessments of child behaviour, family functioning, and adverse events. Sleep was measured with diaries and actigraphy.

RESULTS

Melatonin increased total sleep time by 22.4 minutes (95% confidence interval 0.5 to 44.3 minutes) measured by sleep diaries (n=110) and 13.3 (-15.5 to 42.2) measured by actigraphy (n=59). Melatonin reduced sleep onset latency measured by sleep diaries (-37.5 minutes, -55.3 to -19.7 minutes) and actigraphy (-45.3 minutes, -68.8 to -21.9 minutes) and was most effective for children with the longest sleep latency (P=0.009). Melatonin was associated with earlier waking times than placebo (29.9 minutes, 13.6 to 46.3 minutes). Child behaviour and family functioning outcomes showed some improvement and favoured use of melatonin. Adverse events were mild and similar between the two groups.

CONCLUSIONS

Children gained little additional sleep on melatonin; though they fell asleep significantly faster, waking times became earlier. Child behaviour and family functioning outcomes did not significantly improve. Melatonin was tolerable over this three month period. Comparisons with slow release melatonin preparations or melatonin analogues are required.

TRIAL REGISTRATION

ISRCT No 05534585.

Beware frontotemporal dermoids - they may have intracranial extension: a case of a middle cranial fossa cyst

Congenital orbitofacial dermoid cysts are epithelial lined structures of ectodermal origin that may be associated with sinus tracts and variable deep extension. Midline lesions may extend intracranially, while lateral lesions are thought never to do so. Consequently only midline lesions are usually imaged prior to surgery. We describe a lateral dermoid sinus communicating with an intracerebral dermoid cyst within the middle cranial fossa in a 3 year-old with recurrent periorbital cellulitis and intermittent discharge from a small pimple in the temporal region. This case demonstrates that some lateral "dermoids" need to be treated with more caution if there are unusual features such as dimpling, discharge of material or recurrent wider infection, and preoperative imaging should be carried out to exclude intracranial extension.

Lipoma or liposarcoma? A cautionary case report

MERRF syndrome (myoclonic epilepsy with ragged-red fibres) is a mitochondrial encephalomyopathy characterised by a mixed seizure disorder and myoclonus. The condition is associated with multiple large cervical lipomas that often require surgical excision. Comprehensive clinical examination combined with pre-operative radiographic imaging is vital in such cases to help differentiate benign fatty masses from potential liposarcomas. We describe a case in which a lipoma-like liposarcoma was identified following excision of what was expected, on clinical and radiological grounds, to be a lipoma. This case highlights the potential for sarcomatous changes in suspicious lipomas, and the key role that imaging plays in differentiating benign from malignant.

Greenspace and obesity: a systematic review of the evidence

Greenspace is theoretically a valuable resource for physical activity and hence has potential to contribute to reducing obesity and improving health. This paper reports on a systematic review of quantitative research examining the association between objectively measured access to greenspace and (i) Physical activity, (ii) Weight status and (iii) Health conditions related to elevated weight. Literature searches were conducted in SCOPUS, Medline, Embase and PYSCHINFO. Sixty studies met the inclusion criteria and were assessed for methodological quality and strength of the evidence. The majority (68%) of papers found a positive or weak association between greenspace and obesity-related health indicators, but findings were inconsistent and mixed across studies. Several studies found the relationship varied by factors such as age, socioeconomic status and greenspace measure. Developing a theoretical framework which considers the correlates and interactions between different types of greenspace and health would help study design and interpretation of reported findings, as would improvement in quality and consistency of greenspace access measures. Key areas for future research include investigating if and how people actually use greenspace and improving understanding of the mechanisms through which greenspace can improve health and, in particular, if physical activity is one such mechanism.

Attitudes, social support and environmental perceptions as predictors of active commuting behaviour in school children

BACKGROUND

Environmental perceptions appear to play a role in determining behaviour in children, although their influence on active commuting remains unclear. This study examines whether attitudes, social support and environmental perceptions are associated with active commuting behaviour in school children and whether these associations are moderated by the distance to school.

METHODS

Data were collected as part of the SPEEDY study (Sport, Physical activity and Eating behaviour: Environmental Determinants in Young people), a cross-sectional study of 2064 children from schools in Norfolk, UK. Data regarding the usual mode of travel to school, attitudes towards and social support for active commuting, perceptions of the neighbourhood and route to school were assessed using questionnaires completed by 2012 children and their parents. Distance to school was estimated using a Geographic Information System and this was used to compare associations between personal and environmental factors and active travel, across different distance categories.

RESULTS

Forty per cent of children reported usually walking to school, with 9% cycling and the remainder using motorised travel. Parental attitudes and safety concerns, the presence of social support from parents and friends and parent-reported neighbourhood walkability were all found to be predictors of active commuting, with children receiving peer and family support and living in supportive environments being more likely to walk or cycle. There was some evidence of a moderating effect of distance whereby attitudes were more important for short distances and safety concerns long.

CONCLUSION

Both attitudinal and environmental perceptions are associated with children's active commuting behaviours. Given the difficulty in modifying attitudes directly, the effect on them of interventions to provide more supportive environments should be evaluated.

Astrobiological considerations for the selection of the geological filters on the ExoMars PanCam instrument

The Panoramic Camera (PanCam) instrument will provide visible-near IR multispectral imaging of the ExoMars rover's surroundings to identify regions of interest within the nearby terrain. This multispectral capability is dependant upon the 12 preselected "geological" filters that are integrated into two wide-angle cameras. First devised by the Imager for Mars Pathfinder team to detect iron oxides, this baseline filter set has remained largely unchanged for subsequent missions (Mars Exploration Rovers, Beagle 2, Phoenix) despite the advancing knowledge of the mineralogical diversity on Mars. Therefore, the geological filters for the ExoMars PanCam will be redesigned to accommodate the astrobiology focus of ExoMars, where hydrated mineral terrains (evidence of past liquid water) will be priority targets. Here, we conduct an initial investigation into new filter wavelengths for the ExoMars PanCam and present results from tests performed on Mars analog rocks. Two new filter sets were devised: one with filters spaced every 50 nm ("F1-12") and another that utilizes a novel filter selection method based upon hydrated mineral reflectance spectra ("F2-12"). These new filter sets, along with the Beagle 2 filter set (currently the baseline for the ExoMars PanCam), were tested on their ability to identify hydrated minerals and biosignatures present in Mars analog rocks. The filter sets, with varying degrees of ability, detected the spectral features of minerals jarosite, opaline silica, alunite, nontronite, and siderite present in these rock samples. None of the filter sets, however, were able to detect fossilized biomat structures and small (<2 mm) mineralogical heterogeneities present in silica sinters. Both new filter sets outperformed the Beagle 2 filters, with F2-12 detecting the most spectral features produced by hydrated minerals and providing the best discrimination between samples. Future work involving more extensive testing on Mars analog samples that exhibit a wider range of mineralogies would be the next step in carefully evaluating the new filter sets.

Geographical access to healthcare in Northern England and post-mortem diagnosis of cancer

BACKGROUND

There is some previous evidence that diagnosis of cancer at death, recorded as registry death certificate only records, is associated with problems of access to care.

METHODS

Records from the Northern and Yorkshire Cancer Registry for patients registered with breast, colorectal, lung, ovarian or prostate cancer between 1994 and 2002 were supplemented with measures of travel time to general practitioner and hospital services, and social deprivation. Logistic regression was used to identify predictors of records where diagnosis was at death.

RESULTS

There was no association between the odds diagnosis at death and access to primary care. For all sites except breast, the highest odds of being a cancer diagnosed at death fell among those living in the highest quartile of hospital travel time, although it was only statistically significant for colorectal and ovary tumours. Those in the most deprived and furthest travel time to hospital quartile were 2.6 times more likely to be a diagnosis at death case compared with those in the most affluent and proximal areas.

CONCLUSIONS

There is some evidence that poorer geographical access to tertiary care, in particular when coupled with social disadvantages, may be associated with increased odds of diagnosis at death.

The problems in determining international road mortality

We examined road traffic crash (RTC) fatality rate data for the year 2002 with the object of determining which data source offered the most reliable estimates for international comparison work. Data from the World Health Organisation (WHO) (supplied by national health authorities) and the International Road Federation (IRF) (supplied by national transport authorities) was compared. There were large discrepancies between the rates reported. Discrepancies may be partially explained by the under-reporting of fatalities and by different definitions of road fatality. Two methodologies to adjust for these factors in the IRF database were examined. Neither brought consensus with the WHO RTC fatality rate for all nations. While the WHO provide RTC fatality rates for a wider socio-economic and geographical range of nations than the IRF, the methodology used by the WHO to produce estimates for the least economically developed nations may lead to over-estimation of RTC fatality rate. WHO RTC fatality rates were more strongly associated with variables that are thought to explain RTC fatality rate. We suggest that WHO data may be more suitable than the IRF data for international comparison studies. However, it is advisable that data for the least developed nations be excluded from such work.

Environmental factors and hospitalisation for chronic obstructive pulmonary disease in a rural county of England

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a major global cause of morbidity and mortality. Studies in urban areas have shown associations between air pollutants and hospital admissions for COPD. Whether temporal variations in air quality are associated with hospital admissions for COPD in a rural region with lower concentrations of air pollutants than previously studied was investigated.

METHODS

Daily COPD admissions were recorded for patients attending three hospitals in the county of Norfolk, UK, between January 2006 and February 2007. Records were combined with daily information on concentrations of six air pollutants (carbon monoxide, nitric oxide, nitrogen dioxide, oxides of nitrogen, ozone and fine particulates), airborne pollens, temperature and influenza incidence. A case-crossover analysis was used to examine the association between air pollution and daily admissions.

RESULTS

There were 1050 admissions for COPD over the study period. After adjustment for temperature, pollen and respiratory infections, each 10 microg/m(3) increase in CO was associated with a 2% increase in the odds of admission. Values of 17%, 22% and 9% were observed for NO, NO(2) and oxides of nitrogen respectively. No associations were observed with O(3) or particulates.

CONCLUSION

Among a population of a less urbanised area than previously investigated, this study found evidence that ambient pollutant concentrations were still associated with the risks of hospital admission for COPD.

Travel time to hospital and treatment for breast, colon, rectum, lung, ovary and prostate cancer

The aim was to examine the effect of geographical access to treatment services on cancer treatment patterns. Records for patients in northern England with breast, colon, rectal, lung, ovary and prostate tumours were augmented with estimates of travel time to the nearest hospital providing surgery, chemotherapy or radiotherapy. Using logistic regression to adjust for age, sex, tumour stage, selected tumour pathology characteristics and deprivation of place of residence, the likelihood of receiving radiotherapy was reduced for all sites studied with increasing travel time to the nearest radiotherapy hospital. Lung cancer patients living further from a thoracic surgery hospital were less likely to receive surgery, and both lung cancer and rectal cancer patients were less likely to receive chemotherapy if they lived distant from these services. Services provided in only a few specialised centres, involving longer than average patient journeys, all showed an inverse association between travel time and treatment take-up.

Physical basis of colors seen in Congo red-stained amyloid in polarized light

Amyloid stained by Congo red is traditionally said to show apple-green birefringence in polarized light, although in practice various colors may be seen between accurately crossed polarizing filters, called polarizer and analyzer. Other colors are seen as the polarizer and analyzer are uncrossed and sometimes when the slide is rotated. Previously, there has been no satisfactory explanation of these properties. Birefringence means that a material has two refractive indices, depending on its orientation in polarized light. Birefringence can change linearly polarized light to elliptically polarized, which allows light to pass a crossed analyzer. The birefringence of orientated Congo red varied with wavelength and was maximal near its absorption peak, changing from negative (slow axis of transmission perpendicular to smears or amyloid fibrils) on the shortwave side of the peak to positive (slow axis parallel) on the longwave side. This was explained by a property of any light-absorbing substance called anomalous dispersion of the refractive index around an absorption peak. Negative birefringence gave transmission of blue, positive gave yellow, and the mixture was perceived as green. This explains how green occurs in ideal conditions. Additional or strain birefringence in the optical system, such as in glass slides, partly or completely eliminated blue or yellow, giving yellow/green or yellow, and blue/green or blue, which are commonly seen in practice and in illustrations. With uncrossing of polarizer or analyzer, birefringent effects declined and dichroic effects appeared, giving progressive changes from green to red as the plane of polarization approached the absorbing axis and from green to colorless in the opposite way. This asymmetry of effects is useful to pathologists as a confirmation of amyloid. Rather than showing 'apple-green birefringence in polarized light' as often reported, Congo red-stained amyloid, when examined between crossed polarizer and analyzer, should more accurately be said to show anomalous colors.

Can Western developmental screening tools be modified for use in a rural Malawian setting?

OBJECTIVE

To create a more culturally relevant developmental assessment tool for use in children in rural Africa.

DESIGN

Through focus groups, piloting work and validation, a more culturally appropriate developmental tool, based on the style of the Denver II, was created. Age standardised norms were estimated using 1130 normal children aged 0-6 years from a rural setting in Malawi. The performance of each item in the tool was examined through goodness of fit on logistic regression, reliability and interpretability at a consensus meeting. The instrument was revised with removal of items performing poorly.

RESULTS

An assessment tool with 138 items was created. Face, content and respondent validity was demonstrated. At the consensus meeting, 97% (33/34) of gross motor items were retained in comparison to 51% (18/35) of social items, and 86% (69/80) of items from the Denver II or Denver Developmental Screening Test (DDST) were retained in comparison to 69% (32/46) of the newly created items, many of these having poor reliability and goodness of fit. Gender had an effect on 23% (8/35) of the social items, which were removed. Items not attained by 6 years came entirely from the Denver II fine motor section (4/34). Overall, 110 of the 138 items (80%) were retained in the revised instrument with some items needing further modification.

CONCLUSIONS

When creating developmental tools for a rural African setting, many items from Western tools can be adapted. The gross motor domain is more culturally adaptable, whereas social development is difficult to adapt and is culturally specific.

Deworming drugs for treating soil-transmitted intestinal worms in children: effects on growth and school performance

BACKGROUND

In areas where intestinal worm infections occur, the World Health Organization recommends treating all school children at regular intervals with deworming drugs to improve growth and school performance. The evidence base for this policy needs to be established for countries to commit resources to implement these programmes.

OBJECTIVES

To summarize the effects of deworming drugs used to treat soil-transmitted intestinal worms (nematode geohelminths) on growth and school performance in children.

SEARCH STRATEGY

In May 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2007, Issue 2), MEDLINE, EMBASE, LILACS, mRCT, and reference lists.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials (RCTs) comparing deworming drugs for geohelminth worms with placebo or no treatment in children aged 16 years or less, reporting on growth, nutritional status, school performance, or cognition tests.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the trials and evaluated methodological quality; one author extracted data, and another checked a sample. Continuous data were analysed using the weighted mean difference (WMD) with 95% confidence intervals (CI). The random-effects model (RE model) was used in the presence of statistically significant heterogeneity.

MAIN RESULTS

Thirty-four RCTs, including six cluster-RCTs, met the inclusion criteria. Four trials had adequate allocation concealment, and three cluster-RCTs failed to take design effects into account in their analysis. Weight increased after one dose of a deworming drug (WMD 0.34 kg, 95% CI 0.05 to 0.64, RE model; 2448 children, 9 trials); however, there was considerable heterogeneity between trials that was not explained by background intestinal worm infection or intensity. A meta-analysis of multiple dose trials reporting on outcomes within a year of starting treatment showed no significant difference in weight gain (1714 children, 6 trials); however, one cluster-RCT did show effects on weight at one year in a subgroup analysis. In the seven multiple dose trials with follow up beyond 12 months, only one showed a significant increase in weight. Six of seven trials reported clear data on cognitive tests and school performance: five reported no significant effects, and one showed some improvements in three out of 10 cognitive tests.

AUTHORS' CONCLUSIONS

Deworming drugs used in targeted community programmes may be effective in relation to weight gain in some circumstances but not in others. No effect on cognition or school performance has been demonstrated.

Non-invasive ventilation for cystic fibrosis

BACKGROUND

Non-invasive ventilation (NIV) may be a means to temporarily reverse or slow the progression of respiratory failure in cystic fibrosis (CF).

OBJECTIVES

To compare the effect of NIV versus no NIV in people with CF.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings. We searched the reference lists of each trial for additional publications possibly containing other trials. Most recent search: October 2006.

SELECTION CRITERIA

Randomised controlled trials comparing a form of pressure preset or volume preset NIV to no NIV in people with acute or chronic respiratory failure in CF.

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed trials for inclusion criteria and methodological quality, and extracted data.

MAIN RESULTS

Fifteen trials were identified; seven trials met the inclusion criteria with a total of 106 participants. Six trials evaluated single treatment sessions only and one evaluated a six-week intervention. Four trials (79 participants) evaluated NIV for airway clearance compared with an alternative chest physiotherapy method and showed that airway clearance may be easier with NIV and people with CF may prefer it. We were unable to find any evidence that NIV increases sputum expectoration, but it did improve some lung function parameters.Three trials (27 participants) evaluated NIV for overnight ventilatory support. Lung function and nocturnal transcutaneous carbon dioxide were evaluated within two trials. Due to the small numbers of participants and statistical issues, there were discrepancies in the results between the RevMan and the original trial analyses. No clear differences were found between NIV compared with oxygen or room air except for exercise performance, which significantly improved with NIV compared to room air over six weeks.

AUTHORS' CONCLUSIONS

Non-invasive ventilation may be a useful adjunct to other airway clearance techniques, particularly in people with CF who have difficulty expectorating sputum. Non-invasive ventilation, when used in addition to oxygen, may improve gas exchange during sleep to a greater extent than oxygen therapy alone in moderate to severe disease. These benefits of NIV have largely been demonstrated in single treatment sessions with small numbers of participants. The impact of this therapy on pulmonary exacerbations and disease progression remain unclear. There is a need for long-term randomised controlled trials which are adequately powered to determine the clinical effects of non-invasive ventilation in CF airway clearance and exercise.

Travel times to health care and survival from cancers in Northern England

The aim was to assess the effect of geographical accessibility on the stage of cancer at diagnosis and survival. Records of 117,097 cases of breast, colorectal, lung, ovary and prostate cancer diagnosed in Northern England between 1994 and 2002 were supplemented with estimates of travel times to the patients' general practitioners (GPs) and hospitals attended, together with measures of access to public transport. Logistic regression and Cox proportional hazards models were used, adjusting for age, sex, whether the first hospital visited was a cancer centre and deprivation of area of residence. Late stage at diagnosis was associated with increasing travel time to GP for breast and colorectal cancers and risk of death was associated with travel time to GP for prostate cancer. Travel times to hospital and other accessibility measures showed no consistent associations with stage at diagnosis or survival, so travel to GP was the only influential factor.

Interventions for helping people recognise early signs of recurrence in bipolar disorder

BACKGROUND

Recurrence rates for bipolar disorder are high despite effective treatments with mood stabiliser drugs. Self-help treatments and psychological treatments that teach patients to recognise and manage early warning symptoms and signs (EWS) of impending manic or depressive episodes are popular with patients. The main aim of such interventions is to intervene early and prevent bipolar episodes, thereby increasing the time to the next recurrence and preventing hospitalisation.

OBJECTIVES

To compare the effectiveness of an EWS intervention plus treatment as usual (TAU ) versus TAU (involving and not involving a psychological therapy) on time to manic, depressive and all bipolar episodes (the primary outcome), hospitalisation, functioning, depressive and manic symptoms.

SEARCH STRATEGY

Relevant studies identified by searching Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Registers (CCDANCTR-Studies and CCDANCTR-References - searched on 20/10/2005), supplemented with hand searching the journal Bipolar Disorders, searching the UK National Research Register, checking reference lists of included studies and contacting authors.

SELECTION CRITERIA

Only randomised controlled trials (RCTs) were included. Participants were adults with a diagnosis of bipolar disorder based on standardised psychiatric criteria.

DATA COLLECTION AND ANALYSIS

Two reviewers independently rated trials for inclusion. Data were extracted from included trials by reviewers using a data extraction sheet. Authors of all the included studies were contacted for any additional information required. Time to recurrence data was summarised as log hazard ratios, dichotomous data as relative risk and continuous data as weighted mean difference, using random effects models to calculate effect size only when there was heterogeneity in the data.

MAIN RESULTS

Eleven RCTs were identified, but only six provided primary outcome data. All six RCTs were of high quality. Time to first recurrence of any type (RE, hazards ratio 0.57, 95% CI 0.39 to 0.82), time to manic/hypomanic episode, time to depressive episode, and percentage of people hospitalised and functioning favoured the intervention group. Neither depressive nor hypomanic symptoms differed between intervention and control groups.

AUTHORS' CONCLUSIONS

This review shows a beneficial effect of EWS in time to recurrence, percentage of people hospitalised and functioning in people with bipolar disorder. However, the absence of data on the primary outcome measure in so many included studies is a source of concern and a potential source of bias. Mental health services should consider routinely providing EWS interventions to adults with bipolar disorder, as they appear to reduce hospitalisation and therefore may be cost-effective.

Nebulised hypertonic saline for cystic fibrosis

BACKGROUND

Lung disease in cystic fibrosis is characterised by impaired mucociliary clearance. Hypertonic saline has been shown to enhance mucociliary clearance in vitro and this may act to lessen the destructive inflammatory process in the airways.

OBJECTIVES

To investigate the effects of treatment with nebulised hypertonic saline on people with cystic fibrosis compared to placebo and or other treatments that enhance mucociliary clearance.

SEARCH STRATEGY

'We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Most recent search of the Trials Register: September 2004.

SELECTION CRITERIA

All controlled trials assessing the effect of hypertonic saline compared to placebo or other mucolytic therapy, for any duration or dose regimen in people with cystic fibrosis of any age or severity.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed all identified trials and all data collected. Trial quality was assessed along with allocation concealment.

MAIN RESULTS

Fourteen controlled trials were identified. Nine trials met the inclusion criteria involving 235 participants with an age range of 6 years to 46 years. Two short-term trials of immediate effect on mucociliary clearance demonstrated that hypertonic saline increased isotope clearance compared to control. Lung function, measured by improvement in forced expiratory volume at one second (FEV1 litre per minute), was observed in four trials. When 3% to 7% saline was used in a volume of 10 ml twice-a-day, in comparison to placebo, hypertonic saline led to a significant increase in FEV1, weighted mean difference 12.20 (95%CI 4.28 to 20.10). Two further trials compared a similar concentration and volume of hypertonic saline to recombinant deoxyribonuclease. Over a three-week period one trial showed a non-significant difference, mean difference 1.60 (95% CI -7.96 to 11.16). However, in a further trial, after 12 weeks treatment in participants with moderate to severe lung disease, recombinant deoxyribonuclease led to a greater increase in FEV1 than hypertonic saline (5 ml twice-daily), mean difference 8.00 (95%CI 2.00 to 14.00). No serious adverse events were noted.

AUTHORS' CONCLUSIONS

Nebulised hypertonic saline improves mucociliary clearance in short-term clinical trials and appears to increase lung function compared to control. In comparison to recombinant deoxyribonuclease it may be less effective at improving lung function after three months. Currently there is insufficient evidence to support the use of hypertonic saline as routine treatment for people with cystic fibrosis.

Manual therapy for asthma

BACKGROUND

A variety of manual therapies with similar postulated biologic mechanisms of action are commonly used to treat patients with asthma. Manual therapy practitioners are also varied, including physiotherapists, respiratory therapists, chiropractic and osteopathic physicians. A systematic review across disciplines is warranted.

OBJECTIVES

To evaluate the evidence for the effects of manual therapies for treatment of patients with bronchial asthma.

SEARCH STRATEGY

We searched for trials in computerized general (EMBASE, CINAHL and MEDLINE) and specialized databases (Cochrane Complementary Medicine Field, Cochrane Rehabilitation Field, Index to Chiropractic Literature (ICL), and Manual, Alternative and Natural Therapy (MANTIS)). In addition, we assessed bibliographies from included studies, and contacted authors of known studies for additional information about published and unpublished trials. Date of most recent search: August 2004.

SELECTION CRITERIA

Trials were included if they: (1) were randomised; (2) included asthmatic children or adults; (3) examined one or more types of manual therapy; and (4) included clinical outcomes with observation periods of at least two weeks.

DATA COLLECTION AND ANALYSIS

All three reviewers independently extracted data and assessed trial quality using a standard form.

MAIN RESULTS

From 473 unique citations, 68 full text articles were retrieved and evaluated, which resulted in nine citations to three RCTs (156 patients) suitable for inclusion. Trials could not be pooled statistically because studies that addressed similar interventions used disparate patient groups or outcomes. The methodological quality of one of two trials examining chiropractic manipulation was good and neither trial found significant differences between chiropractic spinal manipulation and a sham manoeuvre on any of the outcomes measured. One small trial compared massage therapy with a relaxation control group and found significant differences in many of the lung function measures obtained. However, this trial had poor reporting characteristics and the data have yet to be confirmed.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support the use of manual therapies for patients with asthma. There is a need to conduct adequately-sized RCTs that examine the effects of manual therapies on clinically relevant outcomes. Future trials should maintain observer blinding for outcome assessments, and report on the costs of care and adverse events. Currently, there is insufficient evidence to support or refute the use of manual therapy for patients with asthma.

Recombinant human deoxyribonuclease for cystic fibrosis

BACKGROUND

Recombinant human deoxyribonuclease (rhDNase) is currently used to treat pulmonary disease (the major cause of morbidity and mortality) in cystic fibrosis.

OBJECTIVES

To determine whether the use of rhDNase in cystic fibrosis is associated with improved mortality and morbidity compared to placebo or other mucolytics and to identify any adverse events associated with its use.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group trials register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and abstracts from conferences. Date of the most recent search of the Group's register: January 2003.

SELECTION CRITERIA

All randomized and quasi-randomized controlled trials where rhDNase was compared to either placebo, standard therapy or another mucolytic.

DATA COLLECTION AND ANALYSIS

Trials were independently assessed for inclusion criteria and the lead reviewer and a colleague carried out analysis of methodological quality and data extraction.

MAIN RESULTS

The searches identified 38 trials, of which 12 trials met our inclusion criteria, including a total of 2294 participants. Three additional studies examined the health care cost from one of the clinical trials. Ten studies compared rhDNase to placebo; one compared daily rhDNase with hypertonic saline and alternate day rhDNase; and one compared daily rhDNase to hypertonic saline. Study duration varied from six days to two years. The number of deaths was not significant between treatment groups. Lung function improved in the treated groups, with significant differences at one month, three months, six months and two years. The mean percentage change in FEV1in the two largest trials were 5.80 (95% CI 3.99 to 7.61) and 3.24 (95% CI 1.03 to 5.45). There was no excess of adverse effects except voice alteration (and rash, which were reported more frequently in one trial in the treated groups. Insufficient data were available to analyse differences in antibiotic treatment, inpatient stay and quality of life.

REVIEWER'S CONCLUSIONS

There is evidence to show that therapy with rhDNase over a one month period is associated with an improvement in lung function in CF, results from a trial lasting six months also showed the same effect. Therapy over a two year period (based on one trial) significantly improved FEV1 in children and there was a non-significant reduction in the risk of infective exacerbations. Voice alteration and rash appear to be the only adverse events reported with increased frequency in randomised controlled trials.

Early life exposures and the prevalence of atopic disorders in a sample of school-age infants

This study was undertaken to determine the relationship between genetic factors, early life environmental exposures, and the prevalence of atopic disorders in infants. 402 children attending schools in rural Essex were sampled in June 1999. Logistic regression models were fitted to examine the association between asthma, eczema, and rhinitis prevalence and a range of genetic and environmental risk factors. After adjustment, infant asthma was associated with the report of a serious chest infection before 3 years of age, a parent employed in a professional occupation, an asthmatic mother, and an asthmatic sibling. Amongst infants who had attended nursery school there was also an affect of age at first attendance. Associations with a chest infection and a family history of atopic conditions were similarly strong predictors of eczema and rhinitis prevalence. The results suggest that genetic influences and patterns of exposure to infections appear to be the greatest influences on the development of infant atopy.

Drug therapies for reducing gastric acidity in people with cystic fibrosis

BACKGROUND

Malabsorption of fat and protein contributes to the poor nutritional status in people with cystic fibrosis. Impaired pancreatic function may also result in increased gastric acidity leading in turn to heartburn, peptic ulcers and the impairment of oral pancreatic replacement therapy. The administration of gastric reducing agents has been used as an adjunct to pancreatic enzyme therapy to improve nutritional status, fat malabsorption and gastro-intestinal symptoms in people with cystic fibrosis. It is thus important to establish the current level of evidence regarding potential benefits of drug therapies that reduce gastric acidity in people with cystic fibrosis.

OBJECTIVES

To assess the effect of drug therapies for reducing gastric acidity: in improving nutritional status; on symptoms associated with increased gastric acidity; fat absorption; lung function; quality of life and survival; and to determine if any adverse effects are associated with their use.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group trials register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books and conference proceedings. Most recent search of the Group's register: April 2002.

SELECTION CRITERIA

All randomised and quasi-randomised trials involving agents that reduce gastric acidity compared to placebo or a comparator treatment.

DATA COLLECTION AND ANALYSIS

Both reviewers independently selected trials and assessed trial quality.

MAIN RESULTS

Thirty-six trials were identified from the initial search. Eleven trials with 172 participants were suitable for inclusion. Five trials were limited to children and three trials enrolled only adults. One trial found that drug therapies which reduce gastric acidity improve gastro-intestinal symptoms such as abdominal pain. Five trials reported significant improvement in measures of fat malabsorption. Two trials reported no significant improvement in nutritional status. Only one trial reported measures of respiratory function and one trial reported an adverse effect with prostaglandin E2 analogue misoprostol. No trials have been identified which assess the effectiveness of agents that reduce gastric acidity in improving quality of life, the complications of increased gastric acidity, or survival.

REVIEWER'S CONCLUSIONS

Trials have shown limited evidence that the agents which reduce gastric acidity in people with cystic fibrosis are associated with improvement in gastro-intestinal symptoms and fat absorption. Currently, there is insufficient evidence to indicate whether there is an improvement in nutritional status, lung function, quality of life, or survival. We therefore recommend large, multicentre, randomised controlled clinical trials are undertaken to evaluate these interventions.

Manual therapy for asthma

BACKGROUND

A variety of manual therapies with similar postulated biologic mechanisms of action are commonly used to treat patients with asthma. Manual therapy practitioners are also varied, including physiotherapists, respiratory therapists, chiropractic and osteopathic physicians. A systematic review across disciplines is warranted.

OBJECTIVES

To evaluate the evidence for the effects of manual therapies for treatment of patients with bronchial asthma.

SEARCH STRATEGY

Trials were searched in computerized general (EMBASE, CINAHL and MEDLINE) and specialized databases (Cochrane Complementary Medicine Field, Cochrane Rehabilitation Field, ICL, and MANTIS). In addition, bibliographies from included studies were assessed, and authors of known studies were contacted for additional information about published and unpublished trials. Date of most recent search: February 2002.

SELECTION CRITERIA

Trials were included if they: (1) were randomised; (2) included asthmatic children or adults; (3) examined one or more types of manual therapy; and (4) included clinical outcomes.

DATA COLLECTION AND ANALYSIS

All three reviewers independently extracted data and assessed trial quality using a standard form.

MAIN RESULTS

From 393 unique citations, 59 full text articles were retrieved and evaluated, which resulted in nine citations to five RCTs (290 patients) suitable for inclusion. Trials could not be pooled statistically because studies that addressed similar interventions used disparate patient groups or outcomes. The methodological quality of one of two trials examining chiropractic manipulation was good and neither trial found significant differences between chiropractic spinal manipulation and a sham manoeuvre on any of the outcomes measured. Quality of the remaining three trials was poor. One small trial compared massage therapy with a relaxation control group and found significant differences in many of the lung function measures obtained. However, this trial had poor reporting characteristics and the data have yet to be confirmed. One small trial compared chest physiotherapy to placebo and one small trial compared footzone therapy to a no treatment control. Neither trial found differences in lung function between groups.

REVIEWER'S CONCLUSIONS

There is insufficient evidence to support the use of manual therapies for patients with asthma. There is a need to conduct adequately-sized RCTs that examine the effects of manual therapies on clinically relevant outcomes. Future trials should maintain observer blinding for outcome assessments, and report on the costs of care and adverse events. Currently, there is insufficient evidence to support or refute the use of manual therapy for patients with asthma.

Intravenous beta2-agonists for acute asthma in the emergency department

BACKGROUND

Inhaled beta-agonist therapy is central to the management of acute asthma. The use of intravenous beta-agonist agents may also be beneficial in this setting.

OBJECTIVES

To determine the benefit of intravenous (IV) beta2-agonists for severe acute asthma treated in the emergency department.

SEARCH STRATEGY

Randomised controlled trials (RCT) were identified using the Cochrane Airways Group Register which is a compilation of systematic searches of MEDLINE, EMBASE, CINAHL, and CENTRAL as well as hand searching of 20 respiratory journals. Bibliographies from included studies and known reviews were also searched. Primary authors and content experts were contacted to identify eligible studies.

SELECTION CRITERIA

Only RCTs were considered for inclusion. Studies were included if patients presented to the emergency department with acute asthma and were treated with IV selective or nonselective beta2-agonists versus placebo, inhaled beta2-agonists, or other standard of care. Pulmonary function, vital signs, arterial gasses, adverse effects, and/or clinical success could be reported as outcome measures. Two reviewers independently selected potentially relevant articles and selected articles for inclusion. Methodological quality was independently assessed using two scoring systems and two reviewers.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers, and confirmed with corresponding authors. Missing data were obtained from authors or calculated from data present in the papers. Trials were combined using a random effects model for odds ratios (OR) or weighted mean differences (WMD) and reported with 95% confidence intervals (95% CI).

MAIN RESULTS

From 746 identified references, 55 potentially relevant articles were identified and 15 were included. The trials included 584 patients. Overall, selective IV beta2-agonist use conferred no advantage over the comparator regimes. For example, it was associated with a lower PEFR after 60 mins compared to inhaled beta2-agonist, although the difference was not statistically significant (-24.7 l/min; 95%CI 2.9, -52.3). There was no difference in heart rate (4.5 bpm; 95% CI -4.9, 14.0). In the well performed blinded studies there was no difference in autonomic side effects between treatments (Odds Ratio 2.2 (95%CI 0.9, 5.7).

REVIEWER'S CONCLUSIONS

There is no evidence to support the use of IV beta2-agonists in patients with severe acute asthma. These drugs should be given by inhalation. No subgroups were identified in which the IV route should be considered.

1H MR spectroscopy evidence for the varied nature of asymptomatic focal brain lesions in neurofibromatosis type 1

We present the MRI and 1H MR spectroscopy findings in six patients with neurofibromatosis type 1 (NF1) and asymptomatic focal brain lesions. Variations in imaging appearances were seen, including regression of a previously identified lesion. MR spectra for the lesions and corresponding areas of normal brain show significant differences. The lesions could be separated into two groups, one demonstrating only slight metabolite ratio changes relative to normal brain and the other group showing significant increase in choline and decrease in N-acetyl aspartate. The lesion which regressed fell into the second group. These findings are not in agreement with those previously reported and provide evidence for the varied and possibly transient nature of these asymptomatic lesions. The spectroscopy findings suggest that metabolite changes may be present without visible changes on MRI.