Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Introducing ethanol ablation as a treatment for thyroid cysts in the emergency setting

BACKGROUND

Ethanol ablation for the treatment of thyroid cysts has been well documented in the literature as a safe, effective treatment option in the elective setting. This study demonstrates the use of ethanol ablation in the emergency setting.

METHODS

Three patients presenting with airway-threatening compressive symptoms secondary to a thyroid cyst were treated with ethanol ablation within 24 hours of presentation to hospital.

RESULTS

All patients had symptom resolution at a median of nine months follow up post procedure. Sixty-six per cent of patients required only one treatment. There was a median of 100 per cent radiological resolution of the cystic component. The median Glasgow Benefit Inventory score was +27.7, similar to that for tonsillectomy.

CONCLUSION

Ethanol ablation is a safe, cost-effective and efficient treatment option for thyroid cysts in the acute setting.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Applying the behaviour change wheel to develop a smartphone application 'stay-active' to increase physical activity in women with gestational diabetes

BACKGROUND

Physical activity (PA) interventions are an important but underutilised component in the management of gestational diabetes mellitus (GDM). The challenge remains how to deliver cost effective PA interventions that have impact on individual behaviour. Digital technologies can support and promote PA remotely at scale. We describe the development of a behaviourally informed smartphone application (Stay-Active) for women attending an NHS GDM clinic. Stay-Active will support an existing motivational interviewing intervention to increase and maintain PA in this population.

METHODS

The behaviour change wheel (BCW) eight step theoretical approach was used to design the application. It provided a systematic approach to understanding the target behaviour, identifying relevant intervention functions, and specifying intervention content. The target behaviour was to increase and maintain PA. To obtain a behavioural diagnosis, qualitative evidence was combined with focus groups on the barriers and facilitators to PA in women with GDM. The findings were mapped onto the Capability Opportunity Motivation-Behaviour (COM-B) model and Theoretical Domains Framework to identify what needs to change for the target behaviour and linked to appropriate intervention functions. Finally, behaviour changes techniques (BCT) and modes of delivery that are most likely to serve the intervention functions were selected. Current evidence, patient focus groups and input from key stakeholders informed Stay-Active's development.

RESULTS

We found that psychological capability, reflective and automatic motivation, social and physical opportunity needed to change to increase PA in women with GDM. The four key intervention functions identified were Enablement, Education, Persuasion and Training. Stay-Active incorporates these four intervention functions delivering ten BCTs including: goal setting, credible source, self-monitoring, action planning, prompts and cues. The final design of Stay-Active delivers these BCTs via an educational resource centre, with goal setting and action planning features, personalised performance feedback and individualised promotional messages.

CONCLUSION

The BCW has enabled the systematic and comprehensive development of Stay-Active to promote PA in women with GDM within an NHS Maternity service. The next phase is to conduct a trial to assess the feasibility and acceptability of a multi-component intervention that combines Stay-Active with PA Motivational Interviewing.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

Investigating the association between COVID-19 vaccination and care home outbreak frequency and duration

OBJECTIVES

At the end of 2020, many countries commenced a vaccination programme against SARS-CoV-2. Public health authorities aim to prevent and interrupt outbreaks of infectious disease in social care settings. We aimed to investigate the association between the introduction of the vaccination programme and the frequency and duration of COVID-19 outbreaks in Northern Ireland (NI).

STUDY DESIGN

We undertook an ecological study using routinely available national data.

METHODS

We used Poisson regression to measure the relationship between the number of RT-PCR confirmed COVID-19 outbreaks in care homes, and as a measure of community COVID-19 prevalence, the Office for National Statistics COVID-19 Infection Survey estimated the number of people testing positive for COVID-19 in NI. We estimated the change in this relationship and estimated the expected number of care home outbreaks in the absence of the vaccination programme. A Cox proportional hazards model estimated the hazard ratio of a confirmed COVID-19 care home outbreak closure.

RESULTS

Care home outbreaks reduced by two-thirds compared to expected following the introduction of the vaccination programme, from a projected 1625 COVID-19 outbreaks (95% prediction interval 1553-1694) between 7 December 2020 and 28 October 2021 to an observed 501. We estimated an adjusted hazard ratio of 2.53 of the outbreak closure assuming a 21-day lag for immunity.

CONCLUSIONS

These findings describe the association of the vaccination with a reduction in outbreak frequency and duration across NI care homes. This indicates probable reduced harm and disruption from COVID-19 in social care settings following vaccination. Future research using individual level data from care home residents will be needed to investigate the effectiveness of the vaccines and the duration of their effects.

Interdisciplinarity defines our identity as medical educators

This article was migrated. The article was marked as recommended. Medical education is a broad church. As a young interdisciplinary group of educationalists we discuss some aspects of the relevance of interdisciplinarity to medical education, using our own experiences as exemplars.

Silent growth hormone secreting pituitary adenomas: IGF-1 is not sufficient to exclude growth hormone excess

Circulating insulin-like growth factor-1 (IGF-1) is increasingly being used as a screening test and in ongoing monitoring of treated acromegaly. We here present three cases of women (two of whom were on the oestrogen containing contraceptive pill at the time of presentation) who had normal circulating IGF-1 and no overt clinical features of acromegaly at the time of their pituitary surgery. Postoperatively, all were confirmed to have growth hormone excess in keeping with the presence of active somatotroph pituitary adenomas. We suggest that for optimal patient management, formal evaluation of growth hormone status with oral glucose tolerance testing should ideally be performed on all individuals for whom pituitary surgery is planned.

Assessment of the burden of human African trypanosomiasis by rapid participatory appraisal in three high-risk villages in Urambo District, Northwest Tanzania

BACKGROUND

The public health and socio-economic burden of Human African Trypanosomiasis (HAT) in East Africa is not well documented. Understanding the epidemiology and impact of HAT in such settings is difficult due to a lack of robust surveillance and reporting systems, restricting evidence-based policy development and contributing to the continued neglect of this disease.

OBJECTIVE

To investigate the burden of HAT in Urambo District, Tanzania in order to inform future public health policy.

METHODS

A rapid participatory appraisal (RPA) using a combination of qualitative and quantitative methods was conducted, that included key informant interviews, hospital record analysis, and tools adapted from participatory learning and action.

RESULTS

Three villages adjacent to Ugala Game Reserve appeared to be the most affected. High levels of under-reporting were noted due to a lack of diagnostic tools at peripheral health care facilities and limited access to specialist services. Community stakeholders perceived the health and socio-economic burden of HAT to be similar to that of malaria.

CONCLUSION

The burden of HAT in remote rural communities is difficult to capture through routine surveillance systems alone. The RPA represents an efficient mechanism for engaging communities in public health action for trypanosomiasis control in northwest Tanzania.

Horizontal biases in rats' use of three-dimensional space

Rodent spatial cognition studies allow links to be made between neural and behavioural phenomena, and much is now known about the encoding and use of horizontal space. However, the real world is three dimensional, providing cognitive challenges that have yet to be explored. Motivated by neural findings suggesting weaker encoding of vertical than horizontal space, we examined whether rats show a similar behavioural anisotropy when distributing their time freely between vertical and horizontal movements. We found that in two- or three-dimensional environments with a vertical dimension, rats showed a prioritization of horizontal over vertical movements in both foraging and detour tasks. In the foraging tasks, the animals executed more horizontal than vertical movements and adopted a "layer strategy" in which food was collected from one horizontal level before moving to the next. In the detour tasks, rats preferred the routes that allowed them to execute the horizontal leg first. We suggest three possible reasons for this behavioural bias. First, as suggested by Grobety and Schenk, it allows minimisation of energy expenditure, inasmuch as costly vertical movements are minimised. Second, it may be a manifestation of the temporal discounting of effort, in which animals value delayed effort as less costly than immediate effort. Finally, it may be that at the neural level rats encode the vertical dimension less precisely, and thus prefer to bias their movements in the more accurately encoded horizontal dimension. We suggest that all three factors are related, and all play a part.

Thoracic intradural extramedullary capillary haemangioma

The authors report a rare case of thoracic intradural extramedullary capillary haemangioma, the clinical presentation of which was similar to any other intraspinal mass. Magnetic resonance imaging does not always distinguish this entity from others, but the presence of enlarged vasculature is often a useful clue. Complete resection is the treatment of choice of this hamartomatous lesion.

The effect of modafinil on counter-regulatory and cognitive responses to hypoglycaemia

AIMS/HYPOTHESIS

Our hypothesis is that reducing release of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) with modafinil will enhance symptomatic and hormonal responses to hypoglycaemia.

METHODS

Nine healthy men received, in random order, two 100-mg doses of modafinil or placebo, followed by an insulin clamp in which plasma glucose was either reduced stepwise to 2.4 mmol/l or was sustained at euglycaemia (four studies). Catecholamines, symptom scores and cognitive function were measured.

RESULTS

Modafinil had no effect on the measured parameters during euglycaemia. During hypoglycaemia, autonomic symptom scores were significantly higher with modafinil (increase at lowest plasma glucose concentration 271.3+/-118.9 vs 211.2+/-80.4/40 min, p=0.019), and the heart rate response was increased (12,928+/-184 vs 6773+/-148 bpm/140 min, p=0.016). Deterioration in performance of two cognitive tasks was reduced: Stroop colour-word test (613+/-204 vs 2375+/-161/65 min, p=0.009) and accuracy of a simple reaction task (11.3+/-1.8 vs 9.4+/-3.7, p=0.039).

CONCLUSIONS/INTERPRETATION

We conclude that modafinil improves adrenergic sensitivity and some aspects of cognitive function at hypoglycaemia, possibly by reducing neuronal central GABA concentrations.

Accuracy of magnetic resonance imaging in determining cause of sudden death in adults: comparison with conventional autopsy

AIM

To determine the accuracy and define the limitations of post mortem magnetic resonance imaging (MRI) in determining the cause of sudden death in adults.

METHODS AND RESULTS

Sudden unexpected adult deaths in the community, reported to the Coroner (n = 10), excluding suspicious, violent or potentially drug-related deaths, were submitted to whole body MRI, followed by full invasive autopsy. The MRI scans were reported independently by four radiologists, blinded to the autopsy findings; two had previous experience of post mortem MRI. An abnormality that related to the cause of death as identified at autopsy, was identified by at least one radiologist in eight cases. These were pulmonary consolidation (autopsy finding pneumonia) (n = 1), pneumoperitoneum (autopsy finding perforated peptic ulcer) (n = 2), left ventricular failure (autopsy finding ischaemic heart disease) (n = 4), and disseminated bronchial carcinoma (n = 1). However, in only one case were all radiologists able to provide a confident cause of death (disseminated bronchial carcinoma). In two cases, in which death occurred 2-6 days and 3-6 days before MRI, early decomposition prevented interpretation of the images. Severe coronary artery atheroma was detected at autopsy in 7/10, but these lesions were not detected by MRI. Previous experience in reporting post mortem MRI, without autopsy comparison, did not result in more accurate interpretation of the images.

CONCLUSIONS

This pilot study suggests that post mortem MRI can identify some abnormalities relating to the common causes of sudden death in adults, but there is a need for greater experience in correlating MRI with autopsy findings before a reliable cause of death can be made by MRI alone. Inability to image coronary artery lesions, differentiating thrombus from clot and pulmonary oedema from pneumonic exudates, are specific problems that may be corrected with greater experience and higher resolution scans.

The effects of KATP channel modulators on counterregulatory responses and cognitive function during acute controlled hypoglycaemia in healthy men: a pilot study

AIMS

To examine the effects of agents that alter potassium adenosine triphosphate (KATP) channel activity in beta-cells on cognitive function and counterregulatory hormone responses during acute hypoglycaemia, given the physiological similarities between the pancreatic beta-cell and the hypothalamic glucose-sensitive neurones (GSN) and the widespread distribution of sulphonylurea receptors in neuronal cells throughout the brain.

METHODS

Ten healthy males were studied on four occasions and in random order underwent three stepped hypoglycaemic (plasma glucose aims: 3.4, 2.8, 2.4 mmol/l) and one euglycaemic (plasma glucose aim: 5 mmol/l) insulin clamps. Prior to each hypoglycaemic study, volunteers received either 10 mg glibenclamide, or 5 mg/kg diazoxide or placebo orally. Cognitive function, symptom scores and counterregulatory hormone responses were measured at each glycaemic level.

RESULTS

There was no statistically significant effect of either drug on the symptoms generated or the counterregulatory hormonal response during hypoglycaemia. However, cognitive function was better preserved during hypoglycaemia in the glibenclamide-treated arm, particularly four-choice reaction time which deteriorated at a plasma glucose 2.5 mmol/l compared with 3.0 mmol/l with diazoxide (P = 0.015) and 2.9 mmol/l with placebo (P = 0.114).

CONCLUSIONS

Single doses of pharmacological agents which alter membrane KATP channel activity do not affect the counterregulatory response to hypoglycaemia but may modify cognitive function during cerebral glucopenia. The unexpected effects of glibenclamide on cortical function suggest a novel action of sulphonylureas that warrants further investigation.

The role of hepatic portal glucose sensing in modulating responses to hypoglycaemia in man

AIMS/HYPOTHESIS

The role of glucose sensing cells in the human hepatic portal system in the initiation of the neuroendocrine responses to acute hypoglycaemia is not known. We investigated the effect of raising blood glucose concentrations in the hepatic-portal vein on neurohumoral responses during induction of systemic hypoglycaemia in nine healthy male volunteers.

METHODS

Each subject received an insulin infusion (3 mU.kg(-1).min(-1)) on two occasions, in random order. Variable rate glucose infusion was used to maintain plasma glucose at 5 mmol/l for 60 min, then 3.2 mmol/l for 60 min. At 20 min prior to hypoglycaemia, subjects drank 20 g of glucose in water or water sweetened with saccharin. In five of the volunteers, the oral glucose was labelled with U-13C6 glucose, which showed peak systemic glucose absorption between 90 and 110 min. Five volunteers also repeated the study with a euglycaemic clamp.

RESULTS

Oral glucose was associated with a reduction in the early adrenaline response to hypoglycaemia, the area under the curve from 90 to 110 min falling from 24.02+/-20.84 (means +/- SD) to 15.26+/-13.65 nmol/l per 20 min, p<0.05. Symptom scores (area under curve) decreased from 99.72+/-91.86 to 16.39+/-94.71, p=0.008 (total), 51.8+/-68.61 to 7.78+/-41.61, p=0.03 (autonomic) and 54.17+/-50.61 to 8.6+/-57.99 with oral glucose, p=0.001 (neuroglycopenic). Oral glucose did not influence symptoms during euglycaemia.

CONCLUSION/INTERPRETATION

Our data are compatible with the hypothesis that centrally mediated symptomatic and neuroendocrine responses are attenuated by glucose detection in the hepatic portal vein in humans.

Gamma herpesvirus carrier status of captive artiodactyls

Between 1998 and 2000, 103 individuals of 19 species of the order Artiodactyla at Whipsnade Wild Animal Park were tested for evidence of infection with gamma herpesviruses in order to distinguish between species which are susceptible to malignant catarrhal fever (MCF), caused by alcelaphine herpesvirus-1 (AlHV-1) of wildebeest (Connochaetes sp.) or ovine herpesvirus-2 (OvHV-2) of domestic sheep, and species which carry related viruses sub-clinically. Gamma herpesvirus DNA was detected in the known, or suspected, carrier species: roan antelope (Hippotragus equinus), scimitar-horned oryx (Oryx dammah), gemsbok (Oryx gazella), musk ox (Ovibos muschatus) and mouflon (Ovis musimon). In six other species: lowland anoa (Bubalus depressicornis) yak (Bos grunniens), sitatunga (Tragelaphus spekei), greater kudu (Tragelaphus strepsiceros), waterbuck (Kobus ellipsiprymnus) and Nile lechwe (Kobus megaceros), DNA was present in some newborn calves and over 30% of adults, strongly suggesting a carrier state. In contrast five Père David's deer (Elaphurus davidianus) and two swamp deer (Cervus duvauceli) died of MCF during the study. A virus isolated from scimitar-horned oryx calves produced cytopathic effects in scimitar-horned oryx kidney cell-culture and caused MCF in a rabbit.

Endolymphatic sac tumours

Endolymphatic sac tumours (ELST) are rare tumours of the petrous temporal bone. They may arise sporadically or be associated with von Hippel-Lindau disease. Their differential diagnosis is discussed. We present the clinical and histopathological features of two new patients with ELST and outline the management of their condition. In addition, we review a third case previously reported as a choroid plexus papilloma in which the histology has been re-assessed and the diagnosis changed to ELST. The controversy regarding the cellular origins of adenomatous tumours of the temporal bone is highlighted.

Molecular genetic analysis of the NF2 gene in young patients with unilateral vestibular schwannomas

Neurofibromatosis type 2 (NF2) must be suspected in patients presenting with a unilateral vestibular schwannoma at a young age who are therefore at theoretical risk of developing bilateral disease. We identified 45 patients aged 30 years or less at the onset of symptoms of a unilateral vestibular schwannoma. Molecular genetic analysis of the NF2 gene was completed on peripheral blood samples in all 45 and on 28 tumour samples. No pathogenic NF2 mutations were identified in any of the blood samples. NF2 point mutations were identified in 21/28 (75%) tumour samples and loss of heterozygosity (LOH) in 21/28 (75%) tumour samples. Both mutational hits were identified in 18/28 (65%) tumour samples. In one multilobular tumour, one (presumably first hit) mutation was confirmed which was common to different foci of the tumour, while the second mutational event differed between foci. The molecular findings in this patient were consistent with somatic mosaicism for NF2 and the clinical diagnosis was confirmed with the presence of two meningiomas on a follow up MRI scan. A further patient developed a contralateral vestibular schwannoma on a follow up MRI scan in whom neither of the truncating mutations in the vestibular schwannoma were present in blood. It is important when counselling patients with unilateral vestibular schwannomas to identify (1) those at risk of bilateral disease, (2) those at risk of developing other tumours, and (3) other family members at risk of developing NF2. Comparing tumour and blood DNA cannot exclude mosaicism in the index case and cannot, therefore, be used to predict those at risk of developing further tumours. However, identification of both mutations or one mutation plus LOH in the tumour and exclusion of those mutations in the blood samples of the sibs or offspring of the affected case may be sufficient to render further screening unnecessary in these relatives.

Vascular endothelial growth factor expression correlates with tumour grade and vascularity in gliomas

AIMS

Tumour vascularity and vascular endothelial growth factor (VEGF) expression were studied in 41 primary brain tumours of astrocytic and oligodendroglial origin, in order to define the potential role of VEGF in the vascularization and growth of these tumours.

METHODS AND RESULTS

Two commercial monoclonal antibodies to the VEGF protein (from R&D Systems and NeoMarkers), raised against different isoforms, were utilized. Each monoclonal antibody consistently detected the expression of VEGF in different cell types. The R&D Systems antibody only produced surface staining of endothelial cells in tumour capillaries, whereas staining with the Neomarkers antibody was largely confined to tumour cell cytoplasm. High levels of staining were seen with the R&D Systems and NeoMarkers antibodies in 13 and 14 of 15 glioblastomas, respectively, four and three of five oligodendrogliomas, four and seven of 10 anaplastic astrocytomas, one and three of six low-grade astrocytomas and none and none of five pilocytic astrocytomas. There was a close correlation between VEGF expression, tumour vascularity and grade.

CONCLUSIONS

These findings support a role for VEGF in the angiogenesis of glioblastoma, anaplastic astrocytoma and oligodendroglioma. The distinct immunoreactivities of the two commercial monoclonal antibodies indicate either there is expression of different splice variants of VEGF or that the epitopes are differentially revealed during synthesis, secretion and receptor-binding of the growth factor. This highlights the importance of using more than one antibody in the evaluation of tissue VEGF expression.

The effect of acute hypoglycemia on brain function and activation: a functional magnetic resonance imaging study

The authors' aim was to examine the regional anatomy of brain activation by cognitive tasks commonly used in hypoglycemia research and to assess the effect of acute hypoglycemia on these in healthy volunteers. Eight right-handed volunteers performed a set of cognitive tasks-finger tapping (FT), simple reaction time (SRT), and four-choice reaction time (4CRT)-twice during blood oxygen level-dependent (BOLD) functional magnetic resonance imaging of the brain on two occasions. In study 1 (n = 6), plasma glucose was maintained at euglycemia (5 mmol/l) throughout. In study 2 (n = 6), plasma glucose was reduced to 2.5 mmol/l for the second set. Performance of the tasks resulted in specific group brain activation maps. During hypoglycemia, FT slowed (P = 0.026), with decreased BOLD activation in right premotor cortex and supplementary motor area and left hippocampus and with increased BOLD activation in left cerebellum and right frontal pole. Although there was no significant change in SRT, BOLD activation was reduced in right cerebellum and visual cortex. The 4CRT deteriorated (P = 0.020), with reduction in BOLD activation in motor and visual systems but increased BOLD signal in a large area of the left parietal association cortex, a region involved in planning. Hypoglycemia impairs simple brain functions and is associated with task-specific localized reductions in brain activation. For a task with greater cognitive load, the increased BOLD signal in planning areas is compatible with recruitment of brain regions in an attempt to limit dysfunction. Further investigation of these mechanisms may help devise rational treatment strategies to limit cortical dysfunction during acute iatrogenic hypoglycemia.

Assessment of patellar maltracking using combined static and dynamic MRI

Between January 1995 and Jul 1997, 474 patients with anterior knee pain resistant to conservative treatment were referred for MR of the knee. The MR examination consisted of routine sequences with an additional patellofemoral dynamic examination using a technique that has been developed at this institution. The dynamic study examines both knees simultaneously, with the patient supine and the quadriceps loaded. No gating or restraint apparatus is needed. Patellar subluxation or tilt was present in 188(40%) of cases, bilateral in 104 and unilateral in 84 cases (right 39, left 45). It was classified as mild in 51%, moderate in 39% and severe in 10%. Subluxation was more prevalent in females than males (42% vs. 37%) and this was most obvious in the severe group where 68% were female. In 90 knees selected at random, four measurements of patellofemoral morphology were obtained using reconstructed images from a volume gradient echo sequence. These measurements were correlated with the degree of subluxation or tilt. A tibial tubercle distance greater than 20 mm, a femoral sulcus angle greater than 150 degrees, sulcus depth less than 4 mm were specific for subluxation but no measurement proved to be sufficiently sensitive to preclude a tracking study. MRI can be used to define more precisely the anatomy of the extensor mechanism and its relationship to the femur and tibia, in both a static and dynamic setting. In this way, patients with anterior knee pain can be classified more accurately and the outcomes of treatment more reliably assessed.

Constitutive activation of Lck and Fyn tyrosine kinases in large granular lymphocytes infected with the gamma-herpesvirus agents of malignant catarrhal fever

Large granular lymphocytes (LGL) with a T or natural killer (NK) lymphoblast morphology and indiscriminate (non-major histocompatibility complex-linked) cytotoxicity for a variety of target cells can be derived in culture from the tissues of animals infected with either alcelaphine herpesvirus-1 (AlHV-1) or ovine herpesvirus-2 (OvHV-2). In this study, LGL survival in the absence of exogenous interleukin-2 was inhibited by the protein kinase inhibitor genestein, but not the p70 s6 kinase inhibitor rapamycin. Constitutive activation of the src kinases Lck and Fyn was demonstrated in a bovine LGL line infected with OvHV-2 and in two rabbit LGL lines infected with AlHV-1. The p44 erk1 and p42 erk2 mitogen-activated protein kinases (MAPK) were also constitutively activated in the LGLs but not control T cells. Lck and Fyn kinase activity in the LGLs did not increase after mitogen (concanavalin A or concanavalin A plus phorbol ester) stimulation of the cells, in contrast to control T cells. Control T cells, but not the LGLs, proliferated after mitogen stimulation. An analysis of tyrosine phosphorylated proteins in the cells indicated that the LGLs exhibited some similarities and differences to activated control T cells. The results demonstrate that the activated phenotype of the LGLs, associated with malignant catarrhal fever virus infection and in the absence of exogenous interleukin-2, involves constitutively activated Lck and Fyn kinases. These are normally crucial for the initial activation of T cells via several cell-surface receptors (e.g. the T-cell receptor and CD2). The inability of the LGLs to proliferate in response to mitogen may be due to an inability of Lck and Fyn to become further activated after mitogen stimulation.

Intracranial haemangioendothelioma mimicking a meningioma

A 33-year-old man presented with a history of fits and on initial investigation was suspected of having a left frontal parafalcine meningioma. Initial surgical procedure to excise the lesion had to be abandoned owing to the extreme vascularity of the lesion. Histology revealed it to be a haemangioendothelioma. At a second operation the tumour was completely removed. The histology of this rather uncommon tumour is discussed and the literature is reviewed.

Quantification of early damage in latissimus dorsi muscle grafts

Acute damage in the latissimus dorsi muscle may account for variable clinical results following dynamic cardiomyoplasty and an ischemic cause has been suggested. Using established techniques, we set out to demonstrate and to quantify the acute muscle damage in a rodent model. The left latissimus dorsi muscle of 5 Sprague-Dawley rats was mobilized on its thoracodorsal vascular pedicle, thus interrupting the regional blood supply to its distal part. The undisturbed contralateral muscle served as a matched control. After 24 hours, the muscle was excised and divided into proximal, middle, and distal thirds. Damage was graded histologically and quantified by nitroblue tetrazolium macrohistochemistry. Both methods of assessment correlated well (r=-0.936; P < 0.001) and demonstrated significant damage, principally in the middle and the distal regions of the ischemic muscles. Therefore, the rodent model appears to be useful for investigating the pathogenesis and prevention of acute ischemic damage in the latissimus dorsi graft under conditions resembling the clinical scenario.

Malignant catarrhal fever caused by ovine herpesvirus-2 in pigs in Norway

This paper describes the first cases of malignant catarrhal fever (MCF) in pigs in which the diagnosis was verified aetiologically by polymerase chain reaction (PCR) and DNA analysis and by the demonstration of antibodies. Three pigs on two separate premises showed clinical signs, gross pathological and histopathological lesions which were in many respects similar to those of MCF in ruminants. The pigs were housed adjacent to sheep and DNA of ovine herpesvirus-2 (OHV-2) was detected by PCR in tissues of all the pigs. In addition, antibody to alcelaphine herpesvirus-1 was detected in the serum of the pigs and in five in-contact sheep. It is concluded that the disease described is MCF of pigs caused by OHV-2.

Salmonellosis in Trinidad: evidence for transovarian transmission of Salmonella in farm eggs

The aim of this study was to determine whether the contents of farm eggs in Trinidad are contaminated with Salmonella and if transovarian transmission occurs. 750 fresh eggs from 10 farms supplying 75% of the country's eggs were cultured for Salmonella. Salmonella was found on the egg shells' surfaces from all farms, and in the egg contents from three farms. Isolates were obtained from the cultures of the contents and shells of nine (1.2%) and 35 (4.66%) eggs, respectively (p < 0.005). Serotypes found in the contents were S. enteritidis (0.8%; deduced to be contaminated by transovarian transmission) and S. typhimurium (0.4%); those isolated from the shells (contaminated by faecal transmission) were S. typhimurium (3.06%), S. enteritidis (0.67%), S. ohio (0.27%), S. cerro (0.27%), S. infantis (0.27%) and S. heidelberg (0.13%). This study provides the first evidence for Salmonella and, more importantly, S. enteritidis, in eggs in Trinidad. This is of major public health significance because S. enteritidis infected eggs appear normal and the organism is difficult to detect and control. The consumption of these eggs may increase the risk of Salmonella infection. Food safety practices, particularly the thorough cooking (> or = 70 degrees C) of all egg dishes and the refrigeration (< 10 degrees C) of shell eggs and egg dishes, are recommended.

Molecular genetic analyses of parapoxviruses pathogenic for humans

The current members of the genus parapoxvirus are orf virus (ORFV), bovine papular stomatitis virus (BPSV), pseudocowpoxvirus (PCPV) and parapoxvirus of red deer in New Zealand (PVNZ). BPSV and PCPV are maintained in cattle while ORFV is maintained in sheep and goats, but all three are zoonoses. Only the recently reported PVNZ has yet to be recorded as infecting humans. Tentative members of the genus are camel contagious ecthyma virus, chamois contagious ecthyma virus and sealpoxvirus. The separation of the parapoxviruses into 4 distinct groups has been based on natural host range, pathology and, more recently, on restriction endonuclease and DNA/DNA hybridisation analyses. The latter studies have shown that the parapoxviruses share extensive homology between central regions of their genomes, but much lower levels of relatedness within the genome termini. The high G + C content of parapoxvirus DNA is in contrast to most other poxviruses and suggests that a significant genetic divergence from other genera of this family has occurred. DNA sequencing of portions of the genome of ORFV, the type species of the genus, has allowed a detailed comparison with the fully sequenced genome of the orthopoxvirus, vaccinia virus (VACV). These studies have provided a genetic map of ORFV and revealed a central core of 88 kbp within which the genomic content was strikingly similar to that of VACV. This conservation is not maintained in the genome termini where insertions, deletions and translocations have occurred. The characterisation of specific ORFV genes may lead to the construction of attenuated vaccine strains in which genes such as those with the potential to interfere with the immune response of the host have been deleted. The current ORFV vaccines are living unattenuated virus and vaccination lesions produce virus which contaminates the environment in a manner similar to natural infection. The virus in scab material is relatively resistant to inactivation and this virus both perpetuates the disease in sheep and provides the most likely source of human infections. A vaccine which immunises animals without perpetuating the disease could be the best way of reducing the incidence of ORFV infection of humans. It is likely that protection against infection by ORFV is cell mediated and will require the endogenous production of relevant antigens. We have recently constructed a series of VACV recombinants each of which contains a large multigene fragment of ORFV DNA. Together the recombinants represent essentially all of the ORFV genome in an overlapping manner. Vaccination of sheep with the recombinant library provided protection against challenge with virulent ORFV. Further studies with this library may enable dominant protective antigens of ORFV to be identified and lead to their incorporation into a subunit vaccine.

The epidemiology of louping-ill, a tick borne infection of red grouse (Lagopus lagopus scoticus)

The epidemiology of louping-ill in red grouse was studied in northern Britain concentrating on the possible role of other species and mechanisms of disease persistence. This tick borne viral disease caused heavy mortality in red grouse, particularly chicks. Louping-ill induced mortality reduced the strength of the density dependence that generates the tendency of grouse populations to cycle and in some populations may cause population sinks. Four routes of transmission were examined and non-viraemic transmission of virus between ticks cofeeding on hares was considered significant. Field data supported the hypothesis that disease dynamics is influenced greatly by mountain hares, both as passive amplifiers and as hosts for the tick vector. Genetic variation in louping-ill within Britain was small.

The immune and inflammatory response to orf virus

Orf virus is a zoonotic, epitheliotropic DNA parapox virus that principally infects sheep and goats. The fact that the virus can repeatedly reinfect sheep has provoked an interest in the underlying cellular, virological and molecular mechanisms for its apparent escape from the host protective immune response. The local immune and inflammatory response in skin and the cell phenotype and cytokine response in lymph analysed around a single lymph node are characteristic of an anti-viral response. An unusual feature is the dense accumulation of MHC Class II+ dendritic cells in the skin lesion. The function of these cells is not known. Orf virus virulence genes and activities have been identified that may interfere with the development of the host protective immune and inflammatory response.

Transmission of louping ill virus between infected and uninfected ticks co-feeding on mountain hares

Most of the data on oral infection of ticks by louping ill virus have been obtained from experiments in which animals were infected by syringe inoculation with infectious material. Using infected ticks to mimic the natural situation, we have demonstrated that louping ill (LI) virus transmission can occur from infected to uninfected Ixodes ricinus feeding in close proximity on mountain hares (Lepus timidus). Under these conditions the hares developed either low or undetectable viraemias. Highest prevalence of LI virus infection was observed in recipient nymphs which had fed to repletion between days 3 and 7 post-attachment of virus-infected adults; following engorgement, 56% of nymphs acquired virus. These results demonstrate the efficient transmission of LI virus between co-feeding ticks on naive mountain hares. However, when ticks were allowed to co-feed on virus-immune hares a significant reduction in the frequency of infection was observed. Neither red deer (Cervus elaphus) nor New Zealand White rabbits supported transmission of LI virus. The significance of virus transmission between cofeeding ticks on LI virus epidemiology is discussed.

The need for specialist review of pathology in paediatric cancer

A retrospective histopathological review of 2104 cases of solid tumour was carried out to assess the variability in diagnosis of childhood cancer. Cases were subject to three independent, concurrent opinions from a national panel of specialist pathologists. The conformity between them was analysed using the percentage of agreement and the kappa statistic (kappa), a measure of the level of agreement beyond that which could occur by chance alone, and weighted kappa (w kappa), which demonstrates the degree of variation between opinions. The major groupings of the Birch-Marsden classification were used within which tumours were assigned for kappa analysis according to the clinical significance of the differential diagnoses. The mean agreement for all tumours together was 90%; kappa = 0.82, w kappa = 0.82. Retinoblastoma achieved the highest kappa value (1.0) and lymphoma the lowest (0.66). Of the cases, 16.5% had their original diagnoses amended and the panel confirmed the original diagnosis of paediatric pathologists in 89% of cases compared with 78% for general pathologists. The varying levels of agreement between experts confirm the difficulty of diagnosis in some tumour types, suggesting justification for specialist review in most diagnoses. Specialist training in paediatric pathology is also recommended.

Cytokines and their inhibitors in orf virus infection

The epitheliotropic parapoxvirus, orf virus, can repeatedly infect sheep skin. A specific immune response is generated as reinfections induce smaller lesions with quicker resolution times than primary lesions. Cyclosporin-A treatment abrogates this partial immunity. Cytokine mRNAs detected in lesion biopsies include the transcripts for IL-1 beta, IL-3 GM-CSF, TNF-alpha and, less reproducibly, IFN-gamma. CD4+ T-cells predominate in afferent lymph draining the site of infection, and are the major source of GM-CSF and IFN-gamma. IL-1 beta and IL-8 are also detected. The orf virus genome contains a homologue of mammalian vascular endothelial growth factor that may enhance virulence and a vaccinia virus E3L-like gene which may inhibit the anti-viral effect of the interferons. A GM-CSF inhibitory activity has also been discovered and has been 'chased' into a 10 kb DNA segment of the orf virus genome. These studies indicate that orf virus may temporarily avoid host immunity by a combination of acute, rapid infection and replication in the epidermis and by producing virulence factors that inhibit protective proteins of the host immune and inflammatory response.

Inter- and intracellular heterogeneity of O6-alkylguanine-DNA alkyltransferase expression in human brain tumors: possible significance in nitrosourea therapy

The inter- and intracellular distribution of the DNA repair protein O6-alkylguanine-DNA alkyltransferase (ATase) may be an important factor in the sensitivity or resistance of tumours to treatment with certain alkylating agents, including the methyltriazenes and nitrosoureas. In order to examine this issue 26 human brain tumour sections (23 high grade gliomas and three low grade gliomas) were examined for ATase expression by immunohistochemistry using a rabbit anti-human ATase polyclonal antibody. Positive staining, seen as fine black granules mainly confined to the nucleus, was observed in all the glioma sections examined. There was marked cellular heterogeneity, ranging from cells completely devoid of staining to cells with very intense staining. Semi-quantitatively, in the 23 high grade gliomas examined six had 1+ staining, seven had 2+ staining and 10 had 3+ staining, whereas all three low grade gliomas had 1+ staining. These results are in contrast to published reports showing that approximately 35% of human brain tumour-derived cell lines and xenografts had very low levels of ATase activity and suggest that the complete lack of ATase is not a common occurrence in high grade glioma.

Predicting patterns of sexual acts among homosexual and bisexual youths

OBJECTIVE

This longitudinal study examined predictors of patterns of change in HIV sexual risk acts among homosexual and bisexual adolescent males.

METHOD

A consecutive series of 136 homosexual and bisexual males aged 14-19 years were recruited into the study. Subjects were predominantly Hispanic (51%) and African American (31%) and seeking services at a homosexual-identified community-based agency in New York City. All subjects participated in an intensive HIV intervention program. Patterns of change in HIV sexual risk acts were based on assessments at four points (intake and 3, 6, and 12 months later) and were used to classify youths as demonstrating one of five patterns of anal and oral sexual acts: protected (anal: 45%, oral: 25%), improved (32% and 28%, respectively), relapse (5% and 8%), variable (8% and 15%), and unprotected (10% and 24%). Components of the health belief, self-efficacy, peer influence, coping, and distress models were assessed as predictors of these patterns.

RESULTS

Protected and improved patterns of sexual risk acts were associated with low levels of anxiety, depression, and substance use and high self-esteem.

CONCLUSIONS

These data suggest that HIV interventions must address non-HIV-related issues confronting youths in difficult life circumstances, particularly emotional distress and the role of peer networks for homosexual and bisexual youths.

Persistence and transmission of tick-borne viruses: Ixodes ricinus and louping-ill virus in red grouse populations

The population dynamics of tick-borne disease agents and in particular the mechanisms which influence their persistence are examined with reference to the flavivirus that causes louping-ill in red grouse and sheep. Pockets of infection cause heavy mortality and the infection probably persists as a consequence of immigration of susceptible hosts. Seroprevalence is positively associated with temporal variations in vectors per host, although variation between areas is associated with the abundance of mountain hares. The presence of alternative tick hosts, particularly large mammals, provides additional hosts for increasing tick abundance. Grouse alone can not support the vectors and the pathogen but both can persist when a non-viraemic mammalian host supports the tick population and a sufficiently high number of nymphs bite grouse. These alternative hosts may also amplify virus through non-viraemic transmission by the process of co-feeding, although the relative significance of this has yet to be determined. Another possible route of infection is through the ingestion of vectors when feeding or preening. Trans-ovarial transmission is a potentially important mechanism for virus persistence but has not been recorded with louping-ill and Ixodes ricinus. The influence of non-viraemic hosts, both in the multiplication of vectors and the amplification of virus through non-viraemic transmission are considered significant for virus persistence.

Factors mediating changes in sexual HIV risk behaviors among gay and bisexual male adolescents

OBJECTIVES

Factors mediating changes in sexual behaviors that increase the risk of human immunodeficiency virus (HIV) infection were monitored in a group of gay and bisexual male adolescents.

METHODS

One hundred thirty-six males aged 14 to 19 years (Hispanic, 51%; African-American, 31%) were recruited from one gay-identified agency, were assessed at four points over a 1-year period, and participated in HIV preventive intervention sessions.

RESULTS

Significant reductions occurred in the number of unprotected same-sex anal and oral acts. Those with less risk in their previous sexual history, those who did not engage in commercial sex, and those who attended more HIV intervention sessions were more likely to reduce their sexual risk. The impact of sessions varied significantly by race/ethnicity: African-American youths reduced their risk acts most dramatically. Abstinence was consistently and significantly more likely among younger youths and those who had been abstinent before enrollment. The youths significantly reduced the number of sexual partners following the intervention; this reduction in partners was maintained through the 12-month follow-up and was greatest among youths with no involvement in commercial sexual activity (prostitution).

CONCLUSIONS

The efficacy of HIV prevention programs must be empirically evaluated.