Topsoil porosity prediction across habitats at large scales using environmental variables

Soil porosity and its reciprocal bulk density are important environmental state variables that enable modelers to represent hydraulic function and carbon storage. Biotic effects and their 'dynamic' influence on such state variables remain largely unknown for larger scales and may result in important, yet poorly quantified environmental feedbacks. Existing representation of hydraulic function is often invariant to environmental change and may be poor in some systems, particularly non-arable soils. Here we assess predictors of total porosity across two comprehensive national topsoil (0-15 cm) data sets, covering the full range of soil organic matter (SOM) and habitats (n = 1385 & n = 2570), using generalized additive mixed models and machine learning. Novel aspects of this work include the testing of metrics on aggregate size and livestock density alongside a range of different particle size distribution metrics. We demonstrate that porosity trends in Great Britain are dominated by biotic metrics, soil carbon and land use. Incorporating these variables into porosity prediction improves performance, paving the way for new dynamic calculation of porosity using surrogate measures with remote sensing, which may help improve prediction in data sparse regions of the world. Moreover, dynamic calculation of porosity could support representation of feedbacks in environmental and Earth System Models. Representing the hydrological feedbacks from changes in structural porosity also requires data and models at appropriate spatial scales to capture conditions leading to near-saturated soil conditions. Classification. Environmental Sciences.

The Rheumatoid Arthritis and MUScle (RAMUS) Study: Protocol for an observational single-arm study of skeletal muscle in patients with rheumatoid arthritis receiving tofacitinib

People with rheumatoid arthritis (RA) are disproportionately affected by sarcopenia, the generalised loss of muscle strength and mass, consequently facing an increased risk of falls, functional decline and death. Currently, there are no approved pharmacological treatments for sarcopenia. RA patients who start tofacitinib (a Janus kinase inhibitor) develop small increases in serum creatinine that are not explained by renal function changes and could reflect sarcopenia improvement. The RAMUS Study is a proof of concept, single-arm observational study in which patients with RA who commence tofacitinib according to routine care will be offered participation according to eligibility criteria. Participants will undergo lower limb quantitative magnetic resonance imaging, whole-body dual energy x-ray absorptiometry, joint examination, muscle function testing and blood tests at three time points: prior to starting tofacitinib and 1 and 6 months afterwards. Muscle biopsy will be performed before and 6 months after starting tofacitinib. The primary outcome will be lower limb muscle volume changes following treatment initiation. The RAMUS Study will investigate whether muscle health improves following tofacitinib treatment for RA. Identifying a potential pharmacological treatment for sarcopenia could have important implications for individuals with RA and for older people in general. ISRCTN registry ID: 13364395.

Patient perspectives of atopic dermatitis: comparative analysis of terminology in social media and scientific literature, identified by a systematic literature review

Atopic dermatitis (AD) is a chronic skin disease that significantly impacts patient quality of life (QoL). It is unknown whether patients and physicians have the same interpretation of AD burden. Unmet needs and AD disease burden were evaluated by comparing terminology used in social media with terminology used in scientific literature. AD terminology in social media was identified using the NetBase platform, and natural language processing was performed. Topics and words driving negative sentiment were evaluated overall and in relation to specific symptoms. The systematic review of scientific literature identified publications that included AD and QoL terms was identified from PubMed. Term analysis of titles and abstracts was conducted via natural language processing. The occurrence of topics and co-occurrence of words associated with QoL terms were evaluated. More than 3 million social media mentions (2018-2020) and 1519 scientific publications (2000-2020) were evaluated. There were more negative than positive social media mentions, and flare and pain were common symptoms driving negative sentiment. Face and hands were major drivers of negative sentiment in relation to AD symptoms in social media. Sleep and pain were often mentioned together. In scientific literature, pruritus and depression were the most frequently occurring symptoms. Similarly, pruritus was the most common AD symptom co-occurring with QoL terms in the assessed scientific literature. Social media analyses provide a unique view into the patient experience of AD. Symptoms driving negative sentiment in social media appear to be discordantly represented in scientific literature. Incorporating patient perspectives may improve disease understanding and management.

Research priorities for mitochondrial disorders: Current landscape and patient and professional views

Primary mitochondrial disorders encompass a wide range of clinical presentations and a spectrum of severity. They currently lack effective disease-modifying therapies and have a high mortality and morbidity rate. It is therefore essential to know that competitively funded research designed by academics meets the core needs of people with mitochondrial disorders and their clinicians. Priority setting partnerships are an established collaborative methodology that brings patients, carers and families, charity representatives and clinicians together to try to establish the most pressing and unanswered research priorities for a particular disease. We developed a web-based questionnaire, requesting all patients affected by primary mitochondrial disease, their carers and clinicians to pose their research questions. This yielded 709 questions from 147 participants. These were grouped into overarching themes including basic biology, causation, health services, clinical management, social impacts, prognosis, prevention, symptoms, treatment and psychological impact. Following the removal of "answered questions", the process resulted in a list of 42 discrete, answerable questions. This was further refined by web-based ranking by the community to 24 questions. These were debated at a face-to-face workshop attended by a diverse range of patients, carers, charity representatives and clinicians to create a definitive "Top 10 of unanswered research questions for primary mitochondrial disorders". These Top 10 questions related to understanding biological processes, including triggers of disease onset, mechanisms underlying progression and reasons for differential symptoms between individuals with identical genetic mutations; new treatments; biomarker discovery; psychological support and optimal management of stroke-like episodes and fatigue.

Forecasting stroke-like episodes and outcomes in mitochondrial disease

In this retrospective, multicentre, observational cohort study, we sought to determine the clinical, radiological, EEG, genetics and neuropathological characteristics of mitochondrial stroke-like episodes and to identify associated risk predictors. Between January 1998 and June 2018, we identified 111 patients with genetically determined mitochondrial disease who developed stroke-like episodes. Post-mortem cases of mitochondrial disease (n = 26) were identified from Newcastle Brain Tissue Resource. The primary outcome was to interrogate the clinico-radiopathological correlates and prognostic indicators of stroke-like episode in patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes syndrome (MELAS). The secondary objective was to develop a multivariable prediction model to forecast stroke-like episode risk. The most common genetic cause of stroke-like episodes was the m.3243A>G variant in MT-TL1 (n = 66), followed by recessive pathogenic POLG variants (n = 22), and 11 other rarer pathogenic mitochondrial DNA variants (n = 23). The age of first stroke-like episode was available for 105 patients [mean (SD) age: 31.8 (16.1)]; a total of 35 patients (32%) presented with their first stroke-like episode ≥40 years of age. The median interval (interquartile range) between first and second stroke-like episodes was 1.33 (2.86) years; 43% of patients developed recurrent stroke-like episodes within 12 months. Clinico-radiological, electrophysiological and neuropathological findings of stroke-like episodes were consistent with the hallmarks of medically refractory epilepsy. Patients with POLG-related stroke-like episodes demonstrated more fulminant disease trajectories than cases of m.3243A>G and other mitochondrial DNA pathogenic variants, in terms of the frequency of refractory status epilepticus, rapidity of progression and overall mortality. In multivariate analysis, baseline factors of body mass index, age-adjusted blood m.3243A>G heteroplasmy, sensorineural hearing loss and serum lactate were significantly associated with risk of stroke-like episodes in patients with the m.3243A>G variant. These factors informed the development of a prediction model to assess the risk of developing stroke-like episodes that demonstrated good overall discrimination (area under the curve = 0.87, 95% CI 0.82-0.93; c-statistic = 0.89). Significant radiological and pathological features of neurodegeneration were more evident in patients harbouring pathogenic mtDNA variants compared with POLG: brain atrophy on cranial MRI (90% versus 44%, P < 0.001) and reduced mean brain weight (SD) [1044 g (148) versus 1304 g (142), P = 0.005]. Our findings highlight the often idiosyncratic clinical, radiological and EEG characteristics of mitochondrial stroke-like episodes. Early recognition of seizures and aggressive instigation of treatment may help circumvent or slow neuronal loss and abate increasing disease burden. The risk-prediction model for the m.3243A>G variant can help inform more tailored genetic counselling and prognostication in routine clinical practice.

Patient-reported outcomes from the JADE COMPARE randomized phase 3 study of abrocitinib in adults with moderate-to-severe atopic dermatitis

BACKGROUND

In JADE COMPARE, abrocitinib improved severity of atopic dermatitis (AD) and demonstrated rapid itch relief.

OBJECTIVES

We examined clinically meaningful improvements in selected patient-reported outcomes (PROs).

METHODS

JADE COMPARE was a multicentre, phase 3 randomized, double-blind, placebo-controlled trial. Adults with moderate-to-severe AD were randomized 2:2:2:1 to receive 16 weeks of oral abrocitinib 200 or 100 mg once daily, dupilumab 300 mg subcutaneous injection every 2 weeks, or placebo, with background topical therapy. PROs included Dermatology Life Quality Index (DLQI), Patient-Oriented Eczema Measure (POEM), Night Time Itch Scale (NTIS), Pruritus and Symptoms Assessment for Atopic Dermatitis, Patient Global Assessment, SCORing Atopic Dermatitis, and Hospital Anxiety and Depression Scale.

RESULTS

At week 16, the proportion of patients achieving POEM scores <3 was 21.3% and 11.7% for 200 and 100 mg abrocitinib, 12.4% for dupilumab, and 4.8% for placebo (vs. abrocitinib, P < 0.0001 and P = 0.04). Proportion achieving ≥4-point improvement from baseline in NTIS severity was 64.3% and 52.4% for 200 and 100 mg abrocitinib, 54.0% for dupilumab, and 34.4% for placebo (vs. abrocitinib, P < 0.0001 and P = 0.007). Proportion achieving ≥4-point improvement from baseline in DLQI was 85.0% and 74.4% for 200 and 100 mg abrocitinib, 83.4% for dupilumab, and 59.7% for placebo (vs. abrocitinib, P < 0.0001 and P = 0.005).

CONCLUSION

Significant improvements in PROs were demonstrated with both abrocitinib doses vs. placebo, and abrocitinib 200 mg provided numerically greater effects compared with dupilumab in patients with moderate-to-severe AD.

Risk of cardiac manifestations in adult mitochondrial disease caused by nuclear genetic defects

Objective

Regular cardiac surveillance is advocated for patients with primary mitochondrial DNA disease. However, there is limited information to guide clinical practice in mitochondrial conditions caused by nuclear DNA defects. We sought to determine the frequency and spectrum of cardiac abnormalities identified in adult mitochondrial disease originated from the nuclear genome.

Methods

Adult patients with a genetically confirmed mitochondrial disease were identified and followed up at the national clinical service for mitochondrial disease in Newcastle upon Tyne, UK (January 2009 to December 2018). Case notes, molecular genetics reports, laboratory data and cardiac investigations, including serial electrocardiograms and echocardiograms, were reviewed.

Results

In this cohort-based observational study, we included 146 adult patients (92 women) (mean age 53.6±18.7 years, 95% CI 50.6 to 56.7) with a mean follow-up duration of 7.9±5.1 years (95% CI 7.0 to 8.8). Eleven different nuclear genotypes were identified: TWNK, POLG, RRM2B, OPA1, GFER, YARS2, TYMP, ETFDH, SDHA, TRIT1 and AGK. Cardiac abnormalities were detected in 14 patients (9.6%). Seven of these patients (4.8%) had early-onset cardiac manifestations: hypertrophic cardiomyopathy required cardiac transplantation (AGK; n=2/2), left ventricular (LV) hypertrophy and bifascicular heart block (GFER; n=2/3) and mild LV dysfunction (GFER; n=1/3, YARS2; n=1/2, TWNK; n=1/41). The remaining seven patients had acquired heart disease most likely related to conventional cardiovascular risk factors and presented later in life (14.6±12.8 vs 55.1±8.9 years, p<0.0001).

Conclusions

Our findings demonstrate that the risk of cardiac involvement is genotype specific, suggesting that routine cardiac screening is not indicated for most adult patients with nuclear gene-related mitochondrial disease.

Non-EPI-DWI for Detection, Disease Monitoring, and Clinical Decision-Making in Thyroid Eye Disease

BACKGROUND AND PURPOSE

The Clinical Activity Score is widely used to grade activity of thyroid eye disease and guide treatment decisions, but as a subjective measurement and being confined to the anterior orbit, it has limitations. Non-EPI-DWI of the extraocular muscles may offer advantages as a functional imaging technique with reduced skull base artifacts, but the correlation with the Clinical Activity Score and patient outcome is unknown. Our aim was to establish the correlation between the Clinical Activity Score and non-EPI-DWI and to describe the additional value provided by adjunctive non-EPI-DWI in making clinical decisions.

MATERIALS AND METHODS

This was a retrospective longitudinal study of 31 patients seen in a multidisciplinary thyroid eye disease clinic during 5 years who had at least 1 ophthalmic and endocrine assessment including the Clinical Activity Score and a non-EPI-DWI ADC calculation. The Spearman rank correlation coefficient was used to determine the relationship between the Clinical Activity Score and non-EPI-DWI. A patient flow chart was constructed to evaluate clinical decision-making, and receiver operating characteristics were generated.

RESULTS

From 60 non-EPI-DWI scans, 368 extraocular muscles were selected for analysis. There was a significant positive correlation between the Clinical Activity Score and ADC (r _s = 0.403; 95% CI, 0.312-0.489; P < .001). ADC values were significantly higher in the Clinical Activity Score ≥ 3 group compared with the Clinical Activity Score < 3 group (P < .001). Our patient flow chart identified a third intermediate-severity cohort in which the non-EPI-DWI was particularly useful in guiding clinical decisions.

CONCLUSIONS

The non-EPI-DWI correlated well with the Clinical Activity Score in our patients and was a useful adjunct to the Clinical Activity Score in making clinical decisions, especially in patients with intermediate activity and severity of thyroid eye disease.

Lower urinary tract dysfunction in adult patients with mitochondrial disease

AIMS

Mitochondrial diseases present with a spectrum of clinical features, usually with multiorgan involvement and are often characterized by a loss of smooth muscle function. Hence, we hypothesized that mitochondrial dysfunction may contribute to lower urinary tract (LUT) dysfunction.

METHODS

We performed a prospective cohort study at a single, quaternary, mitochondrial disease referral center, enrolling consecutive adult patients with genetically confirmed mitochondrial disease. Data regarding baseline characteristics and disease burden were gathered. LUT dysfunction was assessed using the International Consultation on Incontinence Modular Questionnaire-Lower Urinary Tract Symptoms (ICIQ-LUTS) questionnaire, bladder voiding efficiency (BVE), and bladder diaries. Patients with one or more features of LUT dysfunction were offered urodynamic testing.

RESULTS

A total of 109 patients were included. Twenty-six percent of patients manifested at least one feature of LUT dysfunction, which was objectively confirmed in all 14 patients who consented to urodynamic investigation. Disease burden, defined by the Newcastle Mitochondrial Disease Adult Scale (NMDAS), demonstrated a linear relationship with ICIQ-LUTS severity (P = .01), with a statistically significant relationship between NMDAS-gastrointestinal scores and LUTS scores (P < .001). Limitations include mutational heterogeneity across the patient cohort.

CONCLUSIONS

This is the largest study exploring LUT in patients with mitochondrial disease and supports previous smaller studies suggesting LUT dysfunction is underrecognized in patients with mitochondrial disease and impacts considerably on their quality of life. We propose a clinical guideline for identifying mitochondrial disease patients at risk of LUT dysfunction.

Height as a Clinical Biomarker of Disease Burden in Adult Mitochondrial Disease

CONTEXT

Abnormal growth and short stature are observed in patients with mitochondrial disease, but it is unclear whether there is a relationship between final adult height and disease severity.

OBJECTIVE

To determine whether patients with genetically confirmed mitochondrial disease are shorter than their peers and whether stature is related to disease severity.

DESIGN

Analysis of final adult height in relation to disease severity as determined by the Newcastle Mitochondrial Disease Adult Scale (NMDAS).

SETTING

UK Mitochondrial Disease Patient Cohort (Mito Cohort).

PATIENTS

575 patients were identified with recorded height, weight, and molecular genetic diagnosis of mitochondrial disease within the Mito Cohort.

MAIN OUTCOME MEASURES

Adult height, body mass index (BMI), and their association with genetic subgroup and disease severity.

RESULTS

Adults with mitochondrial disease were short, with a mean height of -0.49 SD (95% CI, -0.58 to -0.39; n = 575) compared with UK reference data. Patients were overweight, with a BMI SD of 0.52 (95% CI, 0.37 to 0.67; n = 472). The most common genetic subgroup (m.3243A>G mutation) had a height SD of -0.70 (95% CI, -0.85 to -0.54; n = 234) and a BMI SD of 0.12 (95% CI, -0.10 to 0.34; n = 212). NMDAS scores were negatively correlated with height SD (r = -0.25; 95% CI, -0.33 to -0.17; P < 0.001, n = 533). Rate of disease progression also correlated negatively with adult height (P < 0.001).

CONCLUSION

Final height in mitochondrial disease reflects disease severity and rate of disease progression. Mitochondrial dysfunction and associated subclinical comorbidities affect growth plate physiology.

MT-ND5 Mutation Exhibits Highly Variable Neurological Manifestations at Low Mutant Load

Mutations in the m.13094T>C MT-ND5 gene have been previously described in three cases of Leigh Syndrome (LS). In this retrospective, international cohort study we identified 20 clinically affected individuals (13 families) and four asymptomatic carriers. Ten patients were deceased at the time of analysis (median age of death was 10years (range: 5·4months-37years, IQR=17·9years). Nine patients manifested with LS, one with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), and one with Leber hereditary optic neuropathy. The remaining nine patients presented with either overlapping syndromes or isolated neurological symptoms. Mitochondrial respiratory chain activity analysis was normal in five out of ten muscle biopsies. We confirmed maternal inheritance in six families, and demonstrated marked variability in tissue segregation, and phenotypic expression at relatively low blood mutant loads. Neuropathological studies of two patients manifesting with LS/MELAS showed prominent capillary proliferation, microvacuolation and severe neuronal cell loss in the brainstem and cerebellum, with conspicuous absence of basal ganglia involvement. These findings suggest that whole mtDNA genome sequencing should be considered in patients with suspected mitochondrial disease presenting with complex neurological manifestations, which would identify over 300 known pathogenic variants including the m.13094T>C.

Pseudo-obstruction, stroke, and mitochondrial dysfunction: A lethal combination

OBJECTIVES

The m.3243A>G MTTL1 mutation is the most common cause of mitochondrial disease; yet there is limited awareness of intestinal pseudo-obstruction (IPO) in this disorder. We aimed to determine the prevalence, severity, and clinical outcome of patients with m.3243A>G-related mitochondrial disease manifesting with IPO.

METHODS

In this large, observational cohort study, we assessed the clinical, molecular, and radiological characteristics of patients with genetically determined m.3243A>G-related mitochondrial disease, who presented with severe symptoms suggestive of bowel obstruction in the absence of an occluding lesion.

RESULTS

Between January 2009 and June 2015, 226 patients harbouring the m.3243A>G mutation were recruited to the Medical Research Council Centre Mitochondrial Disease Patient Cohort, Newcastle. Thirty patients (13%) presented acutely with IPO. Thirteen of these patients had a preceding history of stroke-like episodes, whereas 1 presented 27 years previously with their first stroke-like episode. Eight patients developed IPO concomitantly during an acute stroke-like episode. Regression analysis suggested stroke was the strongest predictor for development of IPO, in addition to cardiomyopathy, low body mass index and high urinary mutation load. Poor clinical outcome was observed in 6 patients who underwent surgical procedures.

INTERPRETATION

Our findings suggest, in this common mitochondrial disease, that IPO is an under-recognized, often misdiagnosed clinical entity. Poor clinical outcome associated with stroke and acute surgical intervention highlights the importance of the neurologist having a high index of suspicion, particularly in the acute setting, to instigate timely coordination of appropriate care and management with other specialists. Ann Neurol 2016;80:686-692.

Prevalence of nuclear and mitochondrial DNA mutations related to adult mitochondrial disease

OBJECTIVE

The prevalence of mitochondrial disease has proven difficult to establish, predominantly as a result of clinical and genetic heterogeneity. The phenotypic spectrum of mitochondrial disease has expanded significantly since the original reports that associated classic clinical syndromes with mitochondrial DNA (mtDNA) rearrangements and point mutations. The revolution in genetic technologies has allowed interrogation of the nuclear genome in a manner that has dramatically improved the diagnosis of mitochondrial disorders. We comprehensively assessed the prevalence of all forms of adult mitochondrial disease to include pathogenic mutations in both nuclear and mtDNA.

METHODS

Adults with suspected mitochondrial disease in the North East of England were referred to a single neurology center from 1990 to 2014. For the midyear period of 2011, we evaluated the minimum prevalence of symptomatic nuclear DNA mutations and symptomatic and asymptomatic mtDNA mutations causing mitochondrial diseases.

RESULTS

The minimum prevalence rate for mtDNA mutations was 1 in 5,000 (20 per 100,000), comparable with our previously published prevalence rates. In this population, nuclear mutations were responsible for clinically overt adult mitochondrial disease in 2.9 per 100,000 adults.

INTERPRETATION

Combined, our data confirm that the total prevalence of adult mitochondrial disease, including pathogenic mutations of both the mitochondrial and nuclear genomes (≈1 in 4,300), is among the commonest adult forms of inherited neurological disorders. These figures hold important implications for the evaluation of interventions, provision of evidence-based health policies, and planning of future services.

Preoperative physical activity levels and postoperative pulmonary complications post-esophagectomy

Postoperative pulmonary complications (PPCs) after esophagectomy have been reported to occur in 15-30% of patients and are the most common causes of major morbidity and mortality. Risk factors for the development of PPCs include impairment in lung function, cardiac reserve, aerobic capacity, and body composition. Physical activity is associated with these factors but has not been examined in relation to the risk of developing a PPC. The aim of this cross-sectional study was to investigate if there was a difference in physical activity levels, lung function, and body composition in patients who developed a PPC post-esphagectomy compared with those who did not. Consecutive patients were studied preoperatively: (i) lung function with a portable micro-medical spirometer; (ii) body composition analysis using a Tanita BC 418 machine (Tanita Corp., Tokyo, Japan); and (iii) physical activity with an accelerometer (RT3, (StayHealthy, Monrovia, CA, USA)). Thirty-seven patients were studied, mean age 61 ± 9 years. PPCs developed in 10 patients (27%). Smoking status, lung function, and body composition were similar in both groups. For physical activity, there were significant differences in the time spent sedentary (20.0 ± 1.5 h/day [PPC], 18.4 ± 2.1 h/day [non-PPC]; P < 0.05) and in moderate activity (20 ± 13.7 min/day [PPC], 36 ± 20.7 min/day [non PPC]; P < 0.01). Patients who developed a PPC engaged in less physical activity than those who did not; hence, targeting physical activity preoperatively may result in less PPCs.

Assessment of physical fitness for esophageal surgery, and targeting interventions to optimize outcomes

This review examines how higher levels of physiological reserve and fitness can help the patient endure the demands of esophageal surgery. Lung function, body composition, cardiac function, inflammatory mediators and exercise performance are all determinants of fitness. Physical fitness, both as an independent risk factor and through its effect on other risk factors, has been found to be significantly associated with the risk of developing postoperative pulmonary complications (PPCs) in patients following esophagectomy. Respiratory dysfunction preoperatively poses the dominant risk of developing complications, and PPCs are the most common causes of morbidity and mortality. The incidence of PPCs is between 15 and 40% with an associated 4.5-fold increase in operative mortality leading to approximately 45% of all deaths post-esophagectomy. Cardiac complications are the other principal postoperative complications, and pulmonary and cardiac complications are reported to account for up to 70% of postoperative deaths after esophagectomy. Risk reduction in patients planned for surgery is key in attaining optimal outcomes. The goal of this review was to discuss the risk factors associated with the development of postoperative pulmonary complications and how these may be modified prior to surgery with a specific focus on the pulmonary complications associated with esophageal resection. There are few studies that have examined the effect of modifying physical fitness pre-esophageal surgery. The data to date would indicate a need to develop targeted interventions preoperatively to increase physical function with the aim of decreasing postoperative complications.

Sources of stress and psychological morbidity among undergraduate physiotherapy students

OBJECTIVES

Professional education can be a stressful experience for some individuals, and may impact negatively on emotional well-being and academic performance. Psychological morbidity and associated sources of stress have not been investigated extensively in physiotherapy students. This study explored sources of stress, psychological morbidity and possible associations between these variables in undergraduate physiotherapy students.

DESIGN

A questionnaire-based survey. The Undergraduate Sources of Stress Questionnaire was used to identify sources of stress, and the General Health Questionnaire-12 (GHQ-12) was used to rate the prevalence of psychological morbidity, using a conservative GHQ threshold of 3 to 4 to determine probable 'cases'. Uni- and multivariate tests of correlation were used to analyse the data.

SETTING

An Irish educational institution.

PARTICIPANTS

One hundred and twenty-five physiotherapy undergraduate students.

RESULTS

More than one-quarter of all students (27%) scored above the GHQ threshold, indicating probable psychological morbidity. This is higher than the level of psychological morbidity reported by the general population. Regression analysis showed that academic (beta=0.31, P<0.001) and personal (beta=0.50, P<0.001) sources of stress subscales were significant coefficients, explaining 48% of the variance in psychological morbidity after controlling for part-time employment and hours spent studying. Individual significant items from these subscales were stressful events (beta=0.24, P=0.004), mood (beta=0.43, P< or =0.001) and overall level of stress (beta=0.35, P< or =0.001).

CONCLUSIONS

The results highlighted the emotional vulnerability of a significant proportion of physiotherapy students, with academic and personal issues being the greatest concern. While personal causes of stress such as stressful events and mood are more difficult to control, manipulation of curricular factors may have positive effects on academic sources of stress.

Reversible blindness associated with alcoholic ketoacidosis: pseudomethanol intoxication

We report a case of reversible blindness associated with severe acidosis. A 49-year-old female presented with sudden onset of bilateral blindness. A work up for possible etiologic factors including computed tomography failed to reveal any abnormalities except for ethanol induced severe ketoacidosis. Methanol was not detectable in the serum despite an ethanol level of 14.76 mmol/L, effectively ruling out the diagnosis of methanol intoxication. Treatment of the acidosis led to rapid resolution of her blindness. Review of the literature revealed two case reports of reversible blindness associated with severe acidosis in diabetics. The current case underscores the necessity for a clear understanding of the role of severe acidosis as the sole causative factor of reversible bilateral blindness.

A novel and rapid method for culturing pure rat spinal cord astrocytes on untreated glass

Astrocytes are the major population of glial cells, and are key players in the development, maintenance, and functioning of the central nervous system (CNS). Their potential as targets of therapeutic intervention following CNS injury makes the elucidation of their cellular and subcellular physiology a primary research goal. Well defined and pure cell culture systems are required to examine astrocytic physiology, biochemical pathways and underlying responses to pathophysiologically altered conditions. Previously published protocols for establishing primary astrocyte cultures are time- and resource-consuming or suffer high contamination from other undesired cell types. Here we describe a new and simple procedure for producing highly pure ( > 99%) rat primary astrocyte cultures. The method involves a simple mechanical dissociation of harvested spinal cord tissue through a porous membrane and the subsequent plating of the cells on plain, untreated glass coverslips. Astrocytes adhere very well to the untreated glass while other cell types require a substrate such as poly-L-lysine. The method described here is, therefore, ideal for experiments which require highly pure astrocyte cultures.

T-lymphocyte subsets in acute illness

OBJECTIVES

To determine the range of T-lymphocyte subsets (CD4, CD8, and CD4/CD8 ratios) in acutely ill, hospitalized patients and to determine whether these concentrations correlate with illness severity, survival rate, or immunodepression.

DESIGN

Cross-sectional study, comparing Acute Physiology and Chronic Health Evaluation II (APACHE II) scores and the calculated, disease-specific, predicted mortality rate with T-lymphocyte subsets.

SETTING

Urban county hospital intensive care unit (ICU), serving as the designated trauma center.

PATIENTS

One hundred two consecutively admitted ICU patients (72 medical and 30 surgical).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patient clinical data, APACHE II scores, and their associated predicted mortality rate were recorded. Blinded human immunodeficiency virus (HIV) and lymphocyte testing was performed on samples from all patients on ICU admission. Despite only three (2.9%) of 102 patients testing positive for HIV antibodies, 41% (42/102) of patients had CD4 concentrations of < 400 cells/microL, and 29% (29/102) had CD4 concentrations of < 300 cells/microL. Mean CD8 concentrations were even lower, compared with normal laboratory values, resulting in a slight increase in CD4/CD8 ratios, although 16% (16/102) of patients had a CD4/CD8 ratio of < 1. CD4 counts were linearly related to total lymphocyte concentrations (Pearson correlation coefficient = 0.948), but no relationship was found between total lymphocyte or lymphocyte subset counts and APACHE II score, predicted mortality rate, or survival rate.

CONCLUSIONS

Acute illness alone, in the absence of HIV infection, can be associated with profound decreases of T-lymphocyte populations. This problem is unpredictable and does not correlate with severity of illness, predicted mortality rate, or actual mortality rate. No conclusions regarding HIV serostatus or survival can be made based on single measurements of T-cell concentrations in acutely ill hospitalized patients.

Enterobacter agglomerans--associated cotton fever

Cotton fever is usually a benign febrile, leukocytic syndrome of unknown etiology seen in intravenous narcotic abusers. Cotton and cotton plants are heavily colonized with Enterobacter agglomerans. We report a case of cotton fever associated with E agglomerans in which the organism was first isolated from the patient's blood and secondarily from cotton that he had used to filter heroin. Enterobacter agglomerans is with most probability the causal agent of cotton fever. Patients presenting with the classic history should have blood cultures performed and should be started on a regimen of empiric antibiotic therapy.

Evidence that endogenous enkephalins produce delta-opiate receptor mediated neuronal inhibitions in rat dorsal horn

Kelatorphan, a full inhibitor of aminopeptidases, enkephalinase and dipeptidylaminopeptidase, enzymes which degrade the enkephalins, produced inhibitions (around 50%) of dorsal horn C fibre evoked responses in the rat, following local application. The inhibitions were reversed by the selective delta-opiate receptor antagonists ICI 174,864. Furthermore the inhibitions produced by two doses of Tyr-D-Ala-Gly-MePhe-Gly-ol (DAGO), a potent selective mu-opiate receptor agonist, were not altered in the presence of kelatorphan, so demonstrating an additive effect of the mu-agonist and the enzyme inhibitor. The inhibitions produced by the enzyme inhibitor would seem due to an increased availability of endogenous opioids, presumably the enkephalins which act via the delta-opiate receptor.