Can virtual reality headsets be used safely as a distraction method for paediatric orthopaedic patients? A feasibility study

INTRODUCTION

Virtual reality (VR) has been shown to decrease pain and anxiety in clinical areas. The purpose of this study was to assess the feasibility of 'Rescape DR.VR Junior' headset as a distraction method for paediatric orthopaedic patients.

METHODS

An internal risk assessment by medical engineers to determine its safety deemed the device safe to be used only in the venepuncture and plaster rooms, while further investigation is needed to establish its safety in the operating theatre/anaesthetic room. A total of 32 children (age range: 2-15 years) took the option to use the device while they underwent venepuncture or a cast procedure. Anxiety scores, measured on a Likert scale, were collected pre and postprocedure. Participants were asked if they would use the device again. Subjective feedback was also collated from the supervising clinical staff.

RESULTS

A total of 66% (21) showed a reduction in anxiety scores, 28% (9) had no change in score; all scores being mild, 1-3 on the Likert scale; 6% (2) showed an increase in postprocedure score. All participants stated they would use the device again. One patient declined the device. Health professionals also gave positive subjective feedback and they would all use it again with their paediatric patients. No adverse events were recorded.

CONCLUSION

The 'Rescape DR.VR Junior' headset has been found to be a safe and feasible distraction method for use in children in the venepuncture and plaster room. Further research is required to assess its safety and effectiveness in other clinical areas, including the paediatric orthopaedic operating theatre.

Can virtual reality headsets be used safely as a distraction method for paediatric orthopaedic patients? A feasibility study

INTRODUCTION

Virtual reality (VR) has been shown to decrease pain and anxiety in clinical areas. The purpose of this study was to assess the feasibility of 'Rescape DR.VR Junior' headset as a distraction method for paediatric orthopaedic patients.

METHODS

An internal risk assessment by medical engineers to determine its safety deemed the device safe to be used only in the venepuncture and plaster rooms, while further investigation is needed to establish its safety in the operating theatre/anaesthetic room. A total of 32 children (age range: 2-15 years) took the option to use the device while they underwent venepuncture or a cast procedure. Anxiety scores, measured on a Likert scale, were collected pre and postprocedure. Participants were asked if they would use the device again. Subjective feedback was also collated from the supervising clinical staff.

RESULTS

A total of 66% (21) showed a reduction in anxiety scores, 28% (9) had no change in score; all scores being mild, 1-3 on the Likert scale; 6% (2) showed an increase in postprocedure score. All participants stated they would use the device again. One patient declined the device. Health professionals also gave positive subjective feedback and they would all use it again with their paediatric patients. No adverse events were recorded.

CONCLUSION

The 'Rescape DR.VR Junior' headset has been found to be a safe and feasible distraction method for use in children in the venepuncture and plaster room. Further research is required to assess its safety and effectiveness in other clinical areas, including the paediatric orthopaedic operating theatre.

Dog bites and maxillofacial surgery: what can we do?

The number of injuries caused by dog bites is increasing in the United Kingdom. We review patients admitted with dog bites to a single maxillofacial department in a district general hospital over a 21-month period. Data include patients' characteristics, and the site and severity of injury. The relationship of the victim to the animal and its breed and classification were added where possible. In total, 65 patients, mean age 22 years (range 1-71, median 14) were included. There were 84 wounds, and their site and severity were recorded according to the Lackmann classification. Twelve different breeds of dog were responsible for the bites. An appreciable proportion of those injured were young children. Educational strategies should aim to reduce the incidence of all dog bites, particularly in young children, as their needs after initial treatment are complex. We propose specific strategies to reduce the number of these injuries.

The relationship between complaints of night-time heartburn and sleep-related gastroesophageal reflux

This study investigated whether the complaint of night-time heartburn (NHB) as opposed to daytime heartburn (DHB) is a reliable reflection of actual sleep-related reflux events. Three groups of individuals were studied: individuals with complaints of NHB at least twice per week (n = 24), individuals with complaints of DHB (n = 23), and normal participants without any complaints of regular heartburn during the day or night (n = 25). All three groups were studied on one occasion with combined pH monitoring and polysomnography, and subjective questionnaires about sleep disturbance and sleep quality were given to all participants. The NHB group had significantly more sleep-related reflux events compared with both DHB and control groups (P < 0.01). DHB subjects had significantly (P < 0.05) more sleep-related reflux events than normal controls. Total acid contact time (ACT) was significantly (P < 0.05) elevated in the NHB group compared with both the DHB and control group. Sleep-related ACT was also significantly (P < 0.05) elevated in the NHB group compared with the other two groups, while upright (daytime) ACT was not significantly different. The NHB group was significantly (P < 0.05) worse regarding measures of both objective and subjective sleep quality. Subjects with exclusively DHB do have sleep-related reflux that is greater than normal controls. Subjects with NHB have significantly more sleep-related reflux, and both objective and subjective sleep abnormalities compared with normal controls. Complaints of NHB reflect sleep-related reflux events and may be indicative of a more clinically significant condition.

Characteristics of Epstein-Barr virus hepatitis among patients with jaundice or acute hepatitis

BACKGROUND

Abnormal liver blood tests are common in Epstein-Barr virus (EBV) infection, but symptomatic hepatitis is rare. The demographics, clinical features and outcome of EBV hepatitis are incompletely understood, particularly in the elderly people.

AIM

To identify the demographics, presenting features and natural history of EBV hepatitis.

METHODS

Retrospective review of 1995 consecutive patients attending the jaundice hotline clinic over a 13-year period. Data collected included demographic information, presenting features, clinical and laboratory parameters, radiology imaging and clinical outcome.

RESULTS

Seventeen of 1995 (0.85%) had EBV hepatitis. The median age was 40 years (range 18-68 years). Ten of 17 (59%) patients were aged >30 years, and seven of 17 (41%) patients were aged ≥60 years. Fifteen of 17 (88%) patients presented with clinical/biochemical evidence of jaundice. Seventeen of 17 (100%) patients had a serum lymphocytosis at presentation. 2/17 (12%) patients with EBV hepatitis presented with the classical features of infectious mononucleosis (fever, sore throat and lymphadenopathy). Splenomegaly was present in 15/17 (88%) of patients. Symptoms lasted for a median 8 weeks (range 1-12 weeks). Three of 17 (18%) patients required a brief hospital admission.

CONCLUSIONS

In patients presenting with jaundice/hepatitis, EBV hepatitis is an uncommon diagnosis and causes a self-limiting hepatitis. The diagnosis is suggested by the presence of a lymphocytosis and/or splenomegaly. The majority of patients do not have infectious mononucleosis. Compared with infectious mononucleosis, EBV hepatitis affects an older age group, with nearly half of patients being aged more than 60 years. The diagnosis should be considered in all patients with unexplained hepatitis irrespective of their age.

The effect of baclofen on nocturnal gastroesophageal reflux and measures of sleep quality: a randomized, cross-over trial

BACKGROUND

Baclofen, a GABA(b) agonist, has been shown to reduce episodes of gastroesophageal reflux (GER). To determine if baclofen would significantly reduce reflux during sleep, and also improve objective and subjective measures of sleep.

METHODS

Twenty-one individuals with complaints of nighttime heartburn at least twice a week and a Carlsson GERD score of at least 5 were studied. Patients underwent polysomnography (PSG) and simultaneous esophageal pH monitoring on two occasions separated by approximately 1 week in a cross-over design. The night of each polysomnographic study, patients consumed a refluxogenic meal. Baclofen (40 mg) or placebo was given in random order 90 min prior to the start of the PSG.

KEY RESULTS

Baclofen significantly reduced the number of reflux events compared with placebo. Upright and recumbent acid contact times were both reduced by baclofen vs placebo, but the differences were not significant. Regarding sleep outcomes, several variables were significantly improved by baclofen. Total sleep time and sleep efficiency increased, and wake after sleep onset decreased in the baclofen condition compared with placebo. Proportion of Stage 1 sleep was also significantly decreased on baclofen.

CONCLUSIONS & INFERENCES

In addition to reducing the number of reflux events during sleep, baclofen significantly improved several measures of sleep in patients with documented GER and sleep disturbances. Baclofen could therefore be considered as a useful adjunct therapy to proton pump inhibitors (PPIs) in patients with nighttime heartburn and sleep disturbance who continue to have heartburn and/or sleep complaints despite PPI therapy.

Public Perceptions of Health Care Professionals' Participation in Pharmaceutical Marketing

Trust in the nurse—patient relationship is maintained not by how professionals perceive their actions but rather by how the public perceives them. However, little is known about the public's view of nurses and other health care professionals who participate in pharmaceutical marketing. Our study describes public perceptions of health care providers' role in pharmaceutical marketing and compares their responses with those of a random sample of licensed family nurse practitioners. The family nurse practitioners perceived their participation in marketing activities as significantly more ethically appropriate than did the public responders. Further research is warranted before conclusions can be drawn, but these early findings suggest that nurse practitioners should consider a conservative approach to participating in pharmaceutical marketing.

Obstructive sleep apnoea syndrome in morbidly obese children with tibia vara

Morbid obesity and its association with obstructive sleep apnoea syndrome have been increasingly recognised in children. Orthopaedic surgeons are often the primary medical contact for older children with tibia vara, which has long been associated with obesity, but are unfamiliar with the evaluation and treatment of sleep apnoea in children. We reviewed all children with tibia vara treated surgically at one of our institutions over a period of five years. Thirty-seven patients were identified; 18 were nine years of age or older and 13 of these (72%) had morbid obesity and a history of snoring. Eleven children were diagnosed as having sleep apnoea on polysomnography. The incidence of this syndrome in the 18 children aged nine years or older with tibia vara, was 61%. All these patients required pre-operative non-invasive positive-pressure ventilation; tonsillectomy and adenoidectomy were necessary in five (45%). No peri-operative complications related to the airway occurred. There is a high incidence of sleep apnoea in morbidly obese patients with tibia vara. These patients should be screened for snoring and, if present, should be further evaluated for sleep apnoea before corrective surgery is undertaken.

The positioning of rye homologous chromosomes added to wheat through the cell cycle in somatic cells untreated and treated with colchicine

The arrangement of chromosome pairs 5RL and 7R added to the wild type and the ph1b mutant line of hexaploid wheat are analyzed in 2N somatic root tip cells during the cell cycle relative to the arrangement that chromosomes 5RL show in 4N tapetal cells produced after colchicine treatment. Both homologous chromosome pairs are identified at interphase and mitosis by fluorescence in situ hybridization. In nuclei at interphase, chromosomes appear as discrete domains that show the Rabl orientation. Homologous chromosomes are predominantly non-associated and their positioning seems not to be influenced by the Ph1 gene that suppresses homoeologous meiotic pairing. This pattern of arrangement contrasts with the high level of somatic pairing that sister chromosomes show in the interphase that follows chromosome duplication induced by colchicine. Disruption of pairing observed in some 4N nuclei is produced at c-anaphase which suggests no topological redistribution of homologues during conformation of the new nucleus. Homologous chromosomes show no predominant arrangement in ellipsoidal metaphase plates, which contrasts with the preferential opposite location of homologues in human prometaphase rosettes. Differences between chromosomes in the variation of the length through the cell cycle and in the chromatin morphology when the Ph1 is absent suggest different patterns of chromatin condensation in both chromosomes.

Resting energy expenditure of children attending a rehabilitation programme following head injury

STATEMENT OF PURPOSE

Increased resting energy expenditure following head injury is well documented, but whether this increase extends into rehabilitation and whether this is affected by changes in body composition have not been studied. The aim of this study was to determine whether children attending a rehabilitation program following head injury had altered energy expenditure and body composition.

METHODS

Measurements of resting energy expenditure by indirect calorimetry were performed in 21 head injured children (mean age 10.2 +/- 3.8 years). Measurement of body composition was performed using total body potassium.

RESULTS

Measured resting energy expenditure values were widely distributed, ranging from 52.3-156.4% of predicted values, yet the mean percentage predicted using Schofield weight, Schofield weight and height and World Health Organization predictive equations were 97.5%, 97.4% and 98.6%, respectively. Mean percentage of expected total body potassium for weight, height and age for head injured children were 85.1 +/- 15.5%, 89.1 +/- 14.1% and 86.9 +/- 15.9%, thus all showed significant depletion.

CONCLUSIONS

During rehabilitation, using predictive equations to estimate resting energy expenditure in this group revealed a small bias on average but very large bias at the individual level. Head injured children had altered resting energy expenditure and body composition.

Reduced body cell mass following severe head injury in children: implications for rehabilitation

STATEMENT OF PURPOSE

Increased proteolysis, muscle catabolism and altered body composition have been well documented after severe head injury, but the extent of these effects in children, and whether they extend into rehabilitation, have not been studied. This study determined nutritional status and body composition, with particular reference to the body cell mass (BCM), of head injured children at entry into a rehabilitation programme, and compared body composition analysis with anthropometric nutritional assessment.

METHODS

Nineteen head injured children (nine males, 10 females, mean age 9.1 +/- 4.3 years range 1.2-15.1 years) were measured for height, weight and total body potassium (TBK, a measure of body cell mass) on referral to rehabilitation after the acute phase (mean 38.1 days post-injury). Data was compared with expected normative data derived from healthy age and gender matched children. Nutritional status was determined by two separate criteria based on either anthropometric or body composition methods.

RESULTS

The mean percentage of expected TBK for height was 84.4 +/- 15%, significantly below the clinically acceptable level for body cell mass (90% of expected). Using the anthropometric definition, only 1/19 was undernourished, whereas 12/19 had poor nutritional status using body composition (chi 2 = 7.58, p = 0.006).

CONCLUSIONS

The data revealed a significant depletion in the metabolically active BCM in the presence of normal anthropometry, suggestive of significant muscle wasting. These findings have important pathophysiological and clinical implications in the rehabilitation of children following major head trauma.

The effect of the wheat Ph1 locus on chromatin organisation and meiotic chromosome pairing analysed by genome painting

The Ph1 locus in wheat influences homo(eo)logous chromosome pairing. We have analysed its effect on the behaviour and morphology of two 5RL rye telosomes in a wheat background, by genomic in situ hybridisation (GISH), using rye genomic DNA as a probe. Our main objective was to study the effect of different alleles of the Ph1 locus on the morphology and behaviour of the rye telosomes in interphase nuclei of tapetal cells and in pollen mother cells at early stages of meiosis. The telosomes, easily detectable at all stages, showed a brightly fluorescing chromomere in the distal region and a constriction in the proximal part. These diagnostic markers enabled us to define the centromere and telomere regions of the rye telosomes. In the presence of functional copies of Ph1, the rye telosomes associated at pre-leptotene, disjoined and reorganised their shape at leptotene, and became fully homologously paired at zygotene - pachytene. In plants without functional alleles (ph1bph1b), the rye telosomes displayed an aberrant morphology, their premeiotic associations were clearly disturbed and their pairing during zygotene and pachytene was reduced and irregular. The Ph1 locus also influenced the behaviour of rye telosomes in the interphase nuclei of tapetal cells: in Ph1Ph1 plants, the rye telosomes occupied distinct, parallel-oriented domains, whereas in tapetal nuclei of ph1bph1b plants they were intermingled with wheat chromosomes and showed a heavily distorted morphology. The results shed new light on the effect of Ph1, and suggest that this locus is involved in chromosome condensation and/or scaffold organisation. Our explanation might account for various apparently contradictory and pleiotropic effects of this locus on both premeiotic associations of homologues, the regulation of meiotic homo(eo)logous chromosome pairing and synapsis, the resolution of bivalent interlockings and centromere behaviour.

Differential expression of fibroblast growth factor receptors 1 to 4 and ligand genes in late fetal and early postnatal rat lung

To characterize fibroblast growth factor (FGF) gene expression in the late fetal (days E18 to E22) and early postnatal lung (days P0 to P28), when the alveolar region undergoes extensive growth and reorganization, we analyzed the expression of four FGF receptors and six ligands. FGF receptor 1 (FGFR1) RNA levels were first low (E18) before rising late in the postnatal period (P28). FGFR2 RNA levels were detected early (at E18) and then increased (E20-P0) before falling (P2) to below later postnatal levels (P6 to P28). FGFR3 RNA levels were low at first (E18) and then increased, with peak levels in the days after birth (P2 to P10). FGFR4 RNA levels, barely detected in fetal lung (E18 to E22), increased at birth (P0) and remained high postnatally (P2 to P28). In fetal lung, FGF2 (basic FGF) RNA expression levels were low and FGF1 (acidic FGF) RNA levels were not detected: low RNA levels of each ligand were detected postnatally (P7 to P28). FGF3 to 5 and FGF7 RNA were not detected in fetal or postnatal lung. With in situ hybridization, predominantly the smooth muscle cells of large vessels expressed FGFR1 and 4 mRNA; the epithelial cells of large airways expressed FGFR1, 2, and 4; and alveolar cells expressed FGFR2, 3, and 4. Analysis of protein expression first identified FGF2 localized to the basement membrane of large airways and branching epithelial buds, to mesenchymal cells associated with buds, to the putative smooth muscle cells of large airways and vessels, and to pleural- and mesenchymal-associated cells (E18). Immediately before birth, this pattern of expression persisted (E20 to E22), with FGF2 also being expressed by putative smooth muscle cells of smaller airways and vessels (E22). After birth (P0 to P28), FGF2 expression remained relatively high in the smooth muscle cells of large and small vessels and in pleural cells; in airway smooth muscle cells and in most cells in the alveolar region, however, although FGF2 expression persisted in some cells, its intensity decreased with time.

Associations between leaf structure, orientation, and sunlight exposure in five Western Australian communities

Five plant communities in Western Australia, as well as selected desert and Rocky Mountain species of the western USA, were surveyed to evaluate associations among leaf structure, orientational properties, and the sunlight exposure and precipitation characteristic of each community. Selected leaf structural features have been associated previously with photosynthetic function and included shape, thickness, the ratio of thickness to width, stomatal distribution, leaf surface coloration, and the number and distribution of palisade cell layers. Decreases in annual precipitation (<4 to over 15 cm/yr) and increases in total daily sunlight (4.2 to 29.2 mol photons/m1) corresponded strongly to an increase in the percentage of species in a given community with more inclined (more inclined than +/- 45 degrees from horizontal) or thicker leaf mesophyll (>0.4 mm) leaves. Also, the percentage of species with a leaf thickness to width ratio >0.1, which were amphistomatous, or which had palisade cell layers beneath both leaf surfaces, increased from >20% in the highest rainfall and lowest sunlight community to >80% in the community with least rainfall but greatest sunlight exposure. Over 70% of the species in the most mesic, shaded community had lighter abaxial than adaxial leaf surfaces (leaf bicoloration). All of the above structural features were positively associated with a more inclined leaf orientation (r1 = 0.79), except for leaf bicoloration, which was negatively associated (r1 = 0.75). The ratio of adaxial to abaxial light was more strongly associated with leaf bicoloration (r1 = 0.83) and the presence of multiple adaxial and isobilateral palisade cell layers(r1 = 0.80) than with total incident sunlight on just the adaxial leaf surface (r1 = 0.69 and 0.73, respectively). These results provide field evidence that leaf orientation and structure may have evolved in concert to produce a photosynthetic symmetry in leaf structure in response to the amount of sunlight and other limiting factors of the community. This structural symmetry may serve fundamentally to regulate the distribution of both light and CO2 levels inside the leaf and, thus, increase photosynthetic CO2 uptake per unit leaf biomass.

Oral-motor dysfunction and feeding problems in infants with myelodysplasia

Oral motor function and feeding problems have received little attention in infants with myelomeningocele (MMC). We compared objective video assessments of oral motor skills, diet and feeding function of 20 infants (aged 6 months) with MMC, with data from 20, age, gender, and socioeconomically matched healthy infants using the Feeding Assessment Schedule (FAS), Feeding Environment Check (FEC), Tester's Ratings of Infant Behaviour (TRIB), an Infant Feeding Questionnaire (IFQ), and a 24 hour dietary analysis (DQA). MMC infants had significant feeding difficulty, related to sensory motor integration problems such as hypotonicity, positioning, and hand function. Despite these problems, there was minimal behavioural disruption in infants with MMC and their mothers experienced no marked food aversion or negative feeding experiences. MMC infants consumed feedings which were significantly lower in energy than controls, with possible imbalance of other nutrients. These studies indicate that compared with healthy infants MMC infants have significantly altered oral motor function which we speculate could be early features of the Chiari II malformation. The dietary changes may reflect altered energy requirement. Early identification and management of feeding problems associated with this condition is emphasized.

Alpha 3 beta 1 integrin has a crucial role in kidney and lung organogenesis

A mutation was targeted to the murine alpha3 integrin gene. Homozygous mutant mice survived to birth, but died during the neonatal period. The mutation caused abnormal kidney and lung development. Mutant kidneys displayed decreased branching of the medullary collecting ducts, although the number of nephrons was not altered. Proximal tubules exhibited two distinct subsets of abnormalities, with the epithelial cells either containing excess lysosomes or becoming microcystic. In addition, glomerular development was markedly affected. In mutant kidneys, the extent of branching of glomerular capillary loops was decreased, with capillary lumina being wider than normal. The glomerular basement membrane was disorganized and glomerular podocytes were unable to form mature foot processes. Branching of the bronchi in lungs of mutant mice was also decreased and the large bronchi extended to the periphery. These results indicate a role for integrin receptors in basement membrane organization and branching morphogenesis.

Age-related defects in CD2 receptor-induced activation in human T-cell subsets

It is well documented that the proliferative capacity of T cells declines with advancing age. There are, however, conflicting data as to the role of the accessory cell and whether or not this loss in responsiveness extends to all T-cell stimuli and to all T cells. We report here on the capacity of subpopulations of peripheral blood CD4+ T cells from the healthy aged to proliferate in response to anti-CD2 receptor-induced activation in the complete absence of accessory cells by using various exogenous cofactors as second signals. These costimulatory factors included phorbol 12-myristate 13-acetate (PMA), interleukin (IL)-1, IL-2, IL-6 and IL-7 and the monoclonal antibodies, anti-CD28 and anti-CD44. Under these conditions, the proliferative responsiveness of CD4+CD45RO+ T cells from the aged was found to be comparable to young control cells for all stimuli tested, except anti-CD2 plus IL-7. This suggests that signal transduction pathways involving CD2, except IL-7-mediated events, are essentially intact in 'old' memory CD4+ T cells. On the other hand, several cofactors, namely IL-2, IL-6, IL-7 and to a lesser extent IL-1 beta and PMA, failed to support adequately CD2-induced activation in 'old' CD4+CD45RA+ T cells suggesting severe and multiple signalling deficiencies in this subset.

Differential expression and regulation of cytokine mRNAs in normal human CD45R T cell subsets

Cytokine mRNA expression was analyzed by reverse transcriptase (RT)/PCR in extensively purified normal peripheral CD4+CD45R T cell subsets. Both CD45RA+ and CD45 RO+ populations produced mRNAs for interleukin (IL)-2, IL-2 receptor (alpha chain), IL-6 receptor and tumour necrosis factor (TNF)-beta within 3-4 h of activation. Whilst IL-3 and RANTES were also expressed in both subsets, CD45RO+ cells were clearly the major producers of these cytokines. In contrast, mRNA transcripts for IL-1 alpha, IL-4, IL-5, IL-6, IL-10, interferon gamma (IFN-gamma) and the T cell receptor for IL-1 were almost exclusively induced in CD45RO+ T cells. A population of CD4+ T cells co-expressing intermediate levels of both CD45RA and CD45RO, namely CD45RA+/CD45RO+, appeared to be the major producers of IL-6. Addition of cycloheximide (CHx) 4 h after T cell activation resulted in substantial superinduction of IL-2 mRNA in the CD4+CD45RO+ population but had little effect on CD4+CD45RA+ cells. Taken together, these results show that normal CD4+CD45R T cell subsets exhibit distinct cytokine mRNA profiles and that these differ from the patterns displayed by Th1 and Th2 type T helper clones. Furthermore, they suggest for the first time that IL-2 mRNA turnover is differentially regulated in CD45R T cell subsets.

A new method for the concentration of Cryptosporidium oocysts from water

A novel method for the concentration of Cryptosporidium oocysts from water has been developed, based upon the precipitation of calcium carbonate. A 10 l water sample is treated by adding solutions of calcium chloride and sodium bicarbonate and raising the pH value to 10 with sodium hydroxide. Crystals of calcium carbonate form and enmesh particles in the Cryptosporidium oocyst size range. The crystals are allowed to settle, the supernatant fluid is discarded and the calcium carbonate precipitate dissolved in sulphamic acid. The sample can be concentrated further by centrifugation. Recoveries of oocysts from seeded samples of deionized, tap and river water were in excess of 68%.

Routine monitoring of Cryptosporidium oocysts in water using flow cytometry

A flow cytometric method for the routine analysis of environmental water samples for the presence of Cryptosporidium oocysts has been developed. It uses a Coulter Epics Elite flow cytometer to examine water samples and to separate oocysts from contaminating debris by cell sorting. The sorted particles are then rapidly screened by microscopy. The method has been evaluated and compared with direct epifluorescence microscopy on 325 river, reservoir and drinking water samples. The technique was found to be more sensitive, faster and easier to perform than conventional epifluorescent microscopy for the routine examination of water samples for Cryptosporidium.

Immunoblot analysis of IgE and IgG antibodies to honey bee venom: cross sectional and sequential studies in bee sensitive subjects

To investigate the specific IgE and IgG immune response to honey bee venom (bv), we performed immunoblot analysis of sera from 47 bee sensitive subjects and followed the response during and after venom immunotherapy in 15 of these subjects. Fifteen venom proteins varying in molecular size from 20 to 105 kDa were identified as being antigenic and consisted of a high molecular weight (HMW) group (5 to 105 kDa, containing the previously identified allergens B and C) and a low molecular weight group (LMW) containing hyaluronidase and phospholipase A. In general for a given individual the anti-venom IgE and IgG response was qualitatively similar although some variation between individuals was apparent. Reactivity with hyaluronidase and phospholipase A appeared only in those subjects showing reactivity with HMW components. During immunotherapy specific anti-venom IgG and IgE responses tended to be linked. Increased responses being seen against all components in 4 of 12 subjects, reductions in 3 and unchanged responses in the remainder. Following immunotherapy (mean 4.0 years), spontaneous reduction of IgE and IgG was seen in 5 of 5 subjects. Loss of reactivity with the LMW components was prominent in these sera.

Anthropometry and obesity in myelomeningocele

Anthropometric data on 110 myelomeningocele (MMC) subjects in relation to age, sex, level of lesion and ambulation were studied to investigate growth and the occurrence of obesity in MMC. In 52 subjects, indices of obesity were validated against body composition analysis of total body fat (%BF) using body potassium and body water techniques. Most subjects were short and light compared to reference data and became relatively shorter and heavier with age. Overall trunk growth was not affected by the level of lesion, but sitting height was affected by kyphoscoliosis. Arm spans were similar to reference data, but were significantly greater in wheelchair users. Leg length was greatest in those who walked. Body composition data showed excess adipose in many MMC subjects, this tendency increasing with age. When correlated with %BF determined from body composition analysis, common clinical indices of obesity had variable r values (wt/ht2 0.78; wt/sitting ht2 0.77; upper arm fat area 0.75; triceps skinfold 0.74; wt/arm span2 0.68, with the 4 skinfold method correlating best, 0.82). Anthropometric measures, taken with cognizance of level of disability and mobility, can accurately assess body growth and the occurrence of obesity in MMC. The influence of ambulatory activity in promoting normal growth is emphasized.

Body composition in myelomeningocele

Body composition and measures of obesity were evaluated in 59 subjects with myelomeningocele (MMC), aged 0.3-29 y, by anthropometry and measures of body cell mass (BCM) and intra- and extracellular water (ICW and ECW), derived from total body potassium and deuterium-isotope dilution; these results were compared with reference data. Body composition was normal in preambulatory children with MMC. Beyond ages 3-4 y there was significant depletion of BCM and total body water, with maldistribution of water (increased ECW and decreased ICW) and increased percentage body fat above that expected for age and sex. These findings were more pronounced in females and in those with high lesions, and were less pronounced in those who remained ambulatory. These changes may result in metabolic and nutritional maladaption during stress. The relation of BCM, total body water depletion and increased ECW to decreasing ambulatory activity suggests that early nutritional and mobility programs warrant further study.

Autoantibodies in patients with juvenile chronic arthritis and their immediate family relatives

Antibodies to nuclear antigens were assessed in 23 children with juvenile chronic arthritis (JCA) and 66 of their first degree relatives. Serum samples from 16 patients with JCA (70%) and nine relatives (14%) had antinuclear antibodies by indirect immunofluorescence. Antibodies against nuclear antigens in rabbit thymus extract or an erythroblastoid cell line (K562) were detected by countercurrent immunoelectrophoresis and immunoblotting in 16 patients (70%) and 39 family relatives (59%). Immunoblotting did not show any banding patterns common to all patients with JCA, though bands in the 43-45 kD range were detected in 5/23 patients. Anticardiolipin antibodies were found in 7/23 patients. In total, 18/20 families (90%) had members other than the probands with detectable autoantibodies. In five families immunoblotting showed common banding patterns between the probands and other members. This suggests that there might be an inherited trend towards autoimmune responses in some families of patients with JCA.

Frequency and role of low molecular weight IgM in systemic lupus erythematosus. Study of patients from different ethnic origins

Low molecular weight IgM (LMW IgM) is the monomeric subunit of the naturally occurring pentameric IgM. It is not seen in health but has been previously observed in systemic lupus erythematosus (SLE) particularly in those patients with active disease and may reflect an adverse prognostic finding. We have therefore studied the presence of LMW IgM in 33 Chinese or Malay SLE patients (Singapore) and 21 Caucasian patients (Adelaide). LMW IgM was measured using filtration chromatography or by a sensitive immunoblotting technique. LMW IgM was observed in all patients in the Adelaide group and in 32 patients in the Singapore group with slightly greater quantities being seen in the Adelaide group. LMW IgM constituted up to 15.3% of the total IgM and was frequently associated with the presence of other low molecular weight IgM oligomers. In both groups LMW IgM correlated significantly with the total IgM levels (P less than 0.01). In a more detailed study in the Singapore group LMW IgM also correlated significantly with the IgM anticardiolipin levels (P = 0.02) but not with IgG anticardiolipin or with IgG or IgM anti-DNA levels or with rheumatoid factor. Patients with more extensive organ involvement had higher levels of LMW IgM but not at a significant level. We conclude that circulating LMW IgM occurs almost universally in SLE, is closely related to the total IgM levels and appears independent of ethnic background. The significance of LMW IgM in this disorder is unclear.

Molecular size heterogeneity of immunoglobulins in health and disease

The molecular size of serum IgG, IgA and IgM in patients with a variety of monoclonal and polyclonal immune disorders has been determined by a sensitive immunoblotting technique. IgM, IgA and IgG3 paraproteins from patients with B cell lymphoproliferative disorders frequently polymerize with IgA paraproteins demonstrating two polymeric series, the basic unit of the more dominant series being monomeric IgA, and the second consists of a basic unit having a molecular mass of approximately 70 kD heavier than monomeric IgA. The molecular nature of this heavier IgA moiety was shown to be IgA covalently bound with a single molecule of serum albumin or alpha 1 antitrypsin and this moiety was also observed in small quantities in sera from healthy subjects. IgM paraproteins, particularly from patients with malignant lymphoproliferative disorders, consisted of varying proportions of decamers, pentamers and monomers together with other low molecular weight IgM oligomers. Paraproteins from patients with benign conditions showed less tendency to exist in multiple molecular weight forms. Serum immunoglobulins from patients with polyclonal immune disorder also showed molecular sized heterogeneity. Significantly increased levels of dimeric IgA were observed in patients with alcoholic cirrhosis and Felty's syndrome, while low molecular weight IgM was commonly seen in patients with autoimmune disorders. In these latter disorders monomeric IgM correlated significantly with the serum IgM level suggesting a disorder of assembly of the IgM subunits during an ongoing IgM immune response. We have demonstrated considerable molecular size heterogeneity of serum immunoglobulins both in health and disease and have indicated some possible clinical associations.

Low molecular weight IgM in primary biliary cirrhosis

Low molecular weight IgM is the monomeric subunit of pentameric IgM and is not generally found in the blood of healthy individuals. Using a sensitive immunoblotting technique, low molecular weight IgM was detected in all 17 patients with primary biliary cirrhosis and constituted up to 5% of the total circulating IgM. This low molecular weight IgM moiety correlated significantly with total IgM (p less than 0.01) but not with the specific biliary cirrhosis mitochondrial autoantibody anti-M2. Furthermore it was not possible to show that a partially purified sample of low molecular weight IgM contained M2 binding activity. Mitogen stimulated peripheral blood mononuclear cells from two of four patients were observed to secrete low molecular weight IgM in vitro, a finding seen in only one of six healthy subjects. Immunoblot analysis of patients sera revealed the presence of other oligomers of IgM in addition to low molecular weight IgM. In conclusion this study suggests that during the enhanced IgM synthesis observed in primary biliary cirrhosis a defect occurs in the assembly of the IgM pentamer with release of monomeric and oligomeric IgM into the circulation. The pathogenic significance of these circulating low molecular weight IgM species is unknown.