Tumorigenesis and a DNA repair defect in mice with a truncating Brca2 mutation

Germline mutation of the BRCA2 gene carries a high risk of developing breast cancer. To study the function of this gene, we generated a mutation in Brca2 in mice. Unlike other mutations in the Brca2 gene, which are lethal early in embryogenesis when homozygous, some of our homozygous mutant mice survive to adulthood. These animals have a wide range of defects, including small size, improper differentiation of tissues, absence of germ cells and the development of lethal thymic lymphomas. Fibroblasts cultured from BrcaZ-/-embryos have a defect in proliferation that may be mediated by over-expression of p53 and p21Waf1/CIP1. We show that Brca2 is required for efficient DNA repair, and our results suggest that loss of the p53 checkpoint may be essential for tumour progression triggered by mutations in BRCA2.

Absence of Brca2 causes genome instability by chromosome breakage and loss associated with centrosome amplification

Women heterozygous for mutations in the breast-cancer susceptibility genes BRCA1 and BRCA2 have a highly elevated risk of developing breast cancer [1]. BRCA1 and BRCA2 encode large proteins with no sequence similarity to one another. Although involvement in DNA repair and transcription has been suggested, it is still not understood how loss of function of these genes leads to breast cancer [2]. Embryonic fibroblasts (MEFs) derived from mice homozygous for a hypomorphic mutation (Brca2(Tr2014)) within the 3' region of exon 11 in Brca2 [3], or a similar mutation (Brca2(Tr)) [4], proliferate poorly in culture and overexpress the tumour suppressor p53 and the cyclin-dependent kinase inhibitor p21(Waf1/Cip1). These MEFs have intact p53-dependent DNA damage G(1)-S [3] [4] and G(2)-M checkpoints [4], but are impaired in DNA double-strand break repair [3] and develop chromosome aberrations [4]. Here, we report that Brca2(Tr2014/Tr2014) MEFs frequently develop micronuclei. These abnormal DNA-containing bodies were formed through both loss of acentric chromosome fragments and by chromosome missegregation, which resulted in aneuploidy. Absence of Brca2 also led to centrosome amplification, which we found associated with the formation of micronuclei. These data suggest a potential mechanism whereby loss of BRCA2 may, within subclones, drive the loss of cell-cycle regulation genes, enabling proliferation and tumourigenesis.

An SRY-related gene expressed during spermatogenesis in the mouse encodes a sequence-specific DNA-binding protein

SRY, the testis determining gene, encodes a member of a family of DNA binding proteins characterized by an amino acid sequence motif known as the HMG box. Using degenerate primers and the polymerase chain reaction, we have isolated SRY-related cDNAs from adult murine testis RNA. One of these, Sox-5, encodes a 43 kDa HMG-box protein with similarities to transcription activating proteins. Anti-Sox-5 antibody was used to analyse expression of Sox-5 in pre-pubertal testis and in fractionated spermatogenic cells. Sox-5 is restricted to post-meiotic germ cells, being found at highest levels in round spermatids. Sox-5 is a DNA binding protein and binding site selection assays suggest that it can bind specifically to oligonucleotides containing the consensus motif AACAAT. Sry can also bind to this motif, indicating that the Sry family may have overlapping sequence specificities.

The Sry-related HMG box-containing gene Sox6 is expressed in the adult testis and developing nervous system of the mouse

We have cloned and sequenced a full-length cDNA for the HMG box-containing, SRY-related gene Sox6 from mouse. The deduced protein sequence of Sox6 has considerable homology with that of the previously determined Sox5 sequence. It seems likely that these genes have diverged more recently than other members of the SOX gene family, although the two genes map to different chromosomes in the mouse. In common with Sox5, Sox6 is highly expressed in the adult mouse testis and the HMG domains of both proteins bind to the sequence 5'-AACAAT-3'. This suggests that the two genes may have overlapping functions in the regulation of gene expression during spermatogenesis in the adult mouse. However, Sox6 may have an additional role in the mouse embryo, where it is specifically expressed in the developing nervous system.

DNA binding and bending properties of the post-meiotically expressed Sry-related protein Sox-5

Sox-5 is one of a family of genes which show homology to the HMG box region of the testis determining gene SRY. We have used indirect immunofluorescence to show that Sox-5 protein is localized to the nucleus of post-meiotic round spermatids in the mouse testis. In vitro footprinting and gel retardation assays demonstrate that Sox-5 binds specifically to the sequence AACAAT with moderately high affinity (Kd of approximately 10(-9) M). Moreover, interaction of Sox-5 with its target DNA induces a significant bend in the DNA, characteristic of HMG box proteins. Circular dichroism spectroscopy of the Sox-5 HMG box and its specific complex with DNA shows an alteration in the DNA spectrum, perhaps as a consequence of DNA bending, but none in the protein spectrum on complex formation. The dependence of the change in the CD spectrum with protein to DNA ratio demonstrates the formation of a 1:1 complex. Analysis of the structure of the Sox-5 HMG box by 2D NMR suggests that both the location of helical secondary structure as well as the tertiary structure is similar to that of HMG1 box 2.

Systematic review and meta-analysis of randomised controlled trials of gastro-oesophageal reflux interventions for chronic cough associated with gastro-oesophageal reflux

OBJECTIVE

To evaluate the efficacy of treatment for gastro-oesophageal reflux disease (GORD) on chronic cough in children and adults without an underlying respiratory disease.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane, Medline, and Embase databases, references from review articles.

INCLUDED STUDIES

Randomised controlled trials on GORD treatment for cough in children and adults without primary lung disease. Two reviewers independently selected studies and extracted paediatric and adult data on primary (clinical failure) and secondary outcomes.

RESULTS

11 studies were included. Meta-analysis was limited to five studies in adults that compared proton pump inhibitors with placebo. All outcomes favoured proton pump inhibitors: the odds ratio for clinical failure (primary outcome) was 0.24 (95% confidence interval 0.04 to 1.27); number needed to treat (NNT) was 5 (harm 50 to infinity to benefit 2.5). For secondary outcomes, the standardised mean difference between proton pump inhibitors and placebo was -0.51 (-1.02 to 0.01) for mean cough score at the end of the trial and -0.29 (-0.62 to 0.04) for change in cough score at the end of the trial. Subgroup analysis with generic inverse variance analysis showed a significant mean change in cough (-0.41 SD units, -0.75 to -0.07).

CONCLUSION

Use of a proton pump inhibitor to treat cough associated with GORD has some effect in some adults. The effect, however, is less universal than suggested in consensus guidelines on chronic cough and its magnitude of effect is uncertain.

Dichotomy of food and inhalant allergen sensitization in eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EE) is an emerging condition where patients commonly present with symptoms of gastroesophageal reflux disease and fail to respond adequately to anti-reflux therapy. Food allergy is currently recognized as the main immunological cause of EE; recent evidence suggests an etiological role for inhalant allergens. The presence of EE appears to be associated with other atopic illnesses.

OBJECTIVES

To report the sensitization profile of both food and inhalant allergens in our EE patient cohort in relation to age, and to profile the prevalence of other allergic conditions in patients with EE.

METHOD

The study prospectively analyzed allergen sensitization profiles using skin prick tests to common food allergens and inhalant allergens in 45 children with EE. Patch testing to common food allergens was performed on 33 patients in the same cohort. Comorbidity of atopic eczema, asthma, allergic rhinitis and anaphylaxis were obtained from patient history.

RESULTS

Younger patients with EE showed more IgE and patch sensitization to foods while older patients showed greater IgE sensitization to inhalant allergens. The prevalence of atopic eczema, allergic rhinitis and asthma was significantly increased in our EE cohort compared with the general Australian population. A total of 24% of our cohort of patients with EE had a history of anaphylaxis.

CONCLUSION

In children with EE, the sensitization to inhalant allergens increases with age, particularly after 4 years. Also, specific enquiry about severe food reactions in patients presenting with EE is strongly recommended as it appears this patient group has a high incidence of anaphylaxis.

Cloning, chromosomal mapping and expression pattern of the mouse Brca2 gene

A proportion of human breast cancers result from an inherited predisposition to the disease. Mutations in the BRCA2 gene confer a high risk of breast cancer and are responsible for almost half of these cases. The recent cloning of the human BRCA2 gene has revealed that it encodes a large protein having little significant homology to known proteins. Here we describe the mouse Brca2 gene. The gene maps to mouse chromosome 5, consistent with its location on human chromosome 13q12. We have sequenced cDNA for the entire 3329 amino acid Brca2 protein and this has revealed that, like Brca1, Brca2 is relatively poorly conserved between humans and mice. Brca2 is transcribed in a diverse range of mouse tissues, and the pattern of expression is strikingly similar to that of Brca1. Taken together, our data highlight some intriguing similarities between two genes involved in inherited breast cancer susceptibility.

Oral health of children with gastro-esophageal reflux disease: a controlled study

BACKGROUND

The aim of this study was to compare the dental health of children with gastro-esophageal reflux disease (GERD) with a healthy control group.

METHODS

Dental examinations were conducted for 52 children (31 boys and 21 girls) with a definitive history of GERD. For every subject enrolled in the study, a healthy control sibling without the condition was recruited. Medical histories were obtained from medical records, and dental and dietary histories were obtained from parents. The teeth were examined for erosion, dental caries, and enamel hypoplasia, and sampled for Streptococcus mutans.

RESULTS

The prevalence of erosion by teeth was found to be statistically significant between GERD patients (14 per cent) and controls (10 per cent) (p<0.05). GERD patients had erosion in more permanent teeth compared to controls (4 per cent vs 0.8 per cent, p<0.05), and more severe erosion (p<0.05). Caries experience was also higher in GERD patients compared to controls (p<0.05). Although there were more subjects with Streptococcus mutans in the GERD group compared to the control group (42 per cent vs 25 per cent), the difference was not statistically significant.

CONCLUSIONS

Children with GERD have more erosion and dental caries compared to healthy controls and should be targeted for increased preventive and restorative care.

HBV associated nephrotic syndrome: resolution with oral lamivudine

A 6 year old boy presenting with a five month history of fever, lethargy, and anorexia, was found to have hepatitis B associated membranous glomerulonephropathy and nephrotic syndrome. After two months treatment with oral lamivudine, his proteinuria cleared and serum albumin and aminotransferases normalised, associated with disappearance of hepatitis B e antigen (HBeAg) and appearance of anti-HBeAg antibodies. After 12 months, without side effects, lamivudine was discontinued. He remains well 11 months off treatment.

Gastro-oesophageal reflux treatment for prolonged non-specific cough in children and adults

BACKGROUND

Cough is a very common symptom presenting to medical practitioners. Gastroesophageal reflux disease (GORD) is said to be the causative factor in up to 41% of adults with chronic cough. However cough and GORD are common ailments and their co-existence by chance is high. Also cough can induce reflux episodes. Treatment for GORD includes conservative measures (diet manipulation), pharmaceutical therapy (motility or prokinetic agents, H(2) antagonist and proton pump inhibitors (PPI)) and fundoplication.

OBJECTIVES

To evaluate the efficacy of GORD treatment on chronic cough in children and adults with GORD and prolonged cough that is not related to an underlying respiratory disease i.e. non-specific chronic cough.

SEARCH STRATEGY

The Cochrane Register of Controlled Trials (CENTRAL), the Cochrane Airways Group Specialised Register Collaboration and Cochrane Airways Group, MEDLINE and EMBASE databases, review articles and reference lists of relevant articles were searched. The date of last search was 7th April 2006.

SELECTION CRITERIA

All randomised controlled trials on GORD treatment for cough in children and adults without primary lung disease.

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against pre-determined criteria for inclusion. Two independent reviewers selected, extracted and assessed data for inclusion. Authors were contacted for further information. Data was analysed as "intention to treat" as well as "treatment received". Paediatric and adults data were considered separately. Sensitivity analyses were performed.

MAIN RESULTS

Thirteen studies (3 paediatric, 10 adults) were included. Data from six were available for analysis. None of the paediatric studies could be included in meta-analysis. In adults, analysis on use of H(2) antagonist, motility agents and conservative treatment for GORD were not possible (from lack of data) and there were no controlled studies on fundoplication as an intervention. Six adult studies comparing PPI (2-3 months) to placebo were analysed for various outcomes in the meta-analysis. Enrolment of subjects for two studies were primarily from medical clinics and another 4 studies were otolaryngology clinic patients or patients with laryngitis. Using "intention to treat", pooled data from 4 studies resulted in no significant difference between treatment and placebo in total resolution of cough, Odds Ratio 0.46 (95% CI 0.19 to 1.15). Pooled data revealed no overall significant improvement in cough outcomes (end of trial or change in cough scores). Significant differences were only found in sensitivity analyses. A significant improvement in change of cough scores was found in end of intervention (2-3 months) in those receiving PPI with a standardised mean difference of -0.41 (95%CI -0.75, -0.07) using GIV analysis on cross over trials. Two studies reported improvement in cough after 5 days to 2 weeks of treatment.

AUTHORS' CONCLUSIONS

There is insufficient evidence to definitely conclude that GORD treatment with PPI is universally beneficial for cough associated with GORD in adults. The beneficial effect was only seen in sub-analysis and its effect was small. The optimal duration of such a trial of therapy to evaluate response could not be ascertained in the meta-analysis although two RCTs reported significant change by 2 weeks of therapy. Clinicians should be cognisant of a period (natural resolution with time) and placebo effect in studies that utilise cough as an outcome measure. Data in children are inconclusive. Future paediatric and adult studies are needed whereby studies should be double blind, randomised controlled, parallel design, using treatments for at least two months, with validated subjective and objective cough outcomes and include ascertainment of time to respond as well as assessment of acid and/or non acid reflux whilst on therapy.

An objective study of acid reflux and cough in children using an ambulatory pHmetry-cough logger

OBJECTIVE

There are no objective ambulatory studies on the temporal relationship between reflux and cough in children. Commercial pHmetry loggers have slow capture rates (0.25 Hz) that limit objective quantification of reflux and cough. The authors aimed to evaluate if there is a temporal association between cough and acid pH in ambulatory children with chronic cough.

DESIGN, SETTING AND PATIENTS

The authors studied children (aged <14 years) with chronic cough, suspected of acid reflux and considered for pHmetry using a specifically built ambulatory pHmetry-cough logger that enabled the simultaneous ambulatory recording of cough and pH with a fast (10 Hz) capture rate.

MAIN OUTCOME MEASURES

Coughs within (before and after) 10, 30, 60 and 120 s of a reflux episode (pH<4 for >0.5 s).

RESULTS

Analysis of 5628 coughs in 20 children. Most coughs (83.9%) were independent of a reflux event. Cough-reflux (median 19, IQR 3-45) and reflux-cough (24.5, 13-51) sequences were equally likely to occur within 120 s. Within the 10 and 30 s time frame, reflux-cough (10 s=median 2.5, IQR 0-7.25; 30 s=6.5, 1.25-22.25) sequences were significantly less frequent than reflux-no cough (10 s=27, IQR 15-65; 30 s=24.5, 14.5-55.5) sequences, (p=0.0001 and p=0.001, respectively). No differences were found for 60 and 120 s time frame. Cough-reflux sequence (median 1.0, IQR 0-8) within 10 s was significantly less (p=0.0001) than no cough-reflux sequences (median 29.5, 15-67), within 30 s (p=0.006) and 60 s (p=0.048) but not within 120 s (p=0.47).

CONCLUSIONS

In children with chronic cough and suspected of having gastro-oesophageal reflux disease, the temporal relationship between acid reflux and cough is unlikely causal.

Solid-state vs water-perfused catheters to measure colonic high-amplitude propagating contractions

BACKGROUND

  Solid-state (SS) manometry catheters with portable data loggers offer many potential advantages over traditional water-perfused (WP) systems, such as prolonged recordings in a more physiologic ambulatory setting and the lack of risk for water overload. The use of SS catheters has not been evaluated in comparison with perfused catheters in children. This study aims to compare data provided by SS and WP catheters in children undergoing colonic manometry studies.

METHODS

  A SS catheter and a WP catheter were taped together such that their corresponding sensors were at the same location. Simultaneous recordings were obtained using the SS and WP catheters (both 8 channels, 10 cm apart) in 15 children with severe defecation disorders referred for colonic manometry. Signals were recorded for a minimum of 1 h during fasting, 1 h after ingestion of a meal, and 1 h after the administration of bisacodyl. Solid-state signals from the data logger were analyzed against the perfused signals. All high-amplitude propagated contractions (HAPCs), the most recognizable and interpreted colonic motor event, were evaluated for spatial and temporal features including their durations, amplitudes, and propagation velocities.

KEY RESULTS

  A total of 107 HAPCs were detected with SS and 91 with WP catheters. All WP-HAPC were also observed with SS. Linear regression analysis showed that SS catheters tended to give higher readings in the presence of amplitudes <102 mmHg and lower reading with amplitudes >102 mmHg. An opposite trend was found for the duration of contractions. No significant difference was found for HAPC velocity.

CONCLUSIONS & INFERENCES

  SS catheters are more sensitive in recording HAPCs in children with defecation disorders compared with the more traditional WP assembly. There is a difference in measurements of amplitude between the two systems. Solid-state catheters offer potential advantages over WP catheters in children, being portable, safer to use, and may provide data over a more prolonged period.

Treatment of acute asthma: salbutamol via jet nebuliser vs spacer and metered dose inhaler

OBJECTIVE

To compare the efficacy of salbutamol delivered by jet nebuliser (JN) with salbutamol via a pressurised metered dose inhaler (PMDI) and a large volume spacer (Volumatic) for management of acute asthma.

STUDY POPULATION

A total of 160 children aged from 4 to 12 years presenting to an Emergency Department with acute asthma.

METHODS

The study was of multicentre (n=5) randomised, double blind, parallel design. Children weighing less than 25 kg received salbutamol 2.5 mg via the JN or 600 microg (six puffs) from the PMDI. Children over 25 kg received salbutamol 5 mg via the JN or 1200 microg (12 puffs) via the PMDI. Clinical score (range 0-12) and PEF (over 7 years) were recorded at baseline and 15, 30, 45 and 60 mins post administration.

RESULTS

The improvement from baseline at 30 min in the clinical score was 1.87 for JN and 1.43 for PMDI (P=0.09) and at 60 min was 2.15 for JN and 1.12 for PMDI (P=0.0001). The improvement in PEF at 30 min was 51 L min(-1) for JN and 27 L min(-1) for PMDI (P=0.0007) and at 60 min was 57 L min(-1) for JN and 31.5 L min(-1) for PMDI (P=0.001).

CONCLUSION

Administration of salbutamol via a PMDI and a large volume spacer device provides effective relief in the management of acute asthma in children, but to a lesser extent than a jet nebuliser. This difference may represent a dose response effect.

Gastro-oesophageal reflux treatment for prolonged non-specific cough in children and adults

BACKGROUND

Cough is a very common symptom presenting to medical practitioners. Gastroesophageal reflux disease (GORD) is said to be the causative factor in up to 41% of adults with chronic cough. However cough and GORD are common ailments and their co-existence by chance is high. Also cough can induce reflux episodes. Treatment for GORD includes conservative measures (diet manipulation), pharmaceutical therapy (motility or prokinetic agents, H(2) antagonist and proton pump inhibitors (PPI)) and fundoplication.

OBJECTIVES

To evaluate the efficacy of GORD treatment on chronic cough in children and adults with GORD and prolonged cough that is not related to an underlying respiratory disease i.e. non-specific chronic cough.

SEARCH STRATEGY

The Cochrane Register of Controlled Trials (CENTRAL), the Cochrane Airways Group Specialised Register Collaboration and Cochrane Airways Group, MEDLINE and EMBASE databases, review articles and reference lists of relevant articles were searched. The date of last search was 4th April 2004.

SELECTION CRITERIA

All randomised controlled trials on GORD treatment for cough in children and adults without primary lung disease.

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against pre-determined criteria for inclusion. Two independent reviewers selected, extracted and assessed data for inclusion. Authors were contacted for further information. Data was analysed as "intention to treat" as well as "treatment received". Paediatric and adults data were considered separately. Sensitivity analyses were performed.

MAIN RESULTS

11 studies (3 paediatric, 8 adults; 383 participants) were included. None of the paediatric studies could be included in meta-analysis. In adults, analysis on use of H(2) antagonist, motility agents and conservative treatment for GORD were not possible (from lack of data) and there were no controlled studies on fundoplication as an intervention. Five adult studies comparing PPI (2-3 months) to placebo were analysed for various outcomes in the meta-analysis. Enrollment of subjects for two studies were primarily from medical clinics and another three studies were otolaryngeal clinic patients. Using "intention to treat", pooled data from three studies resulted in no significant difference between treatment and placebo in total resolution of cough. Pooled data revealed no significant improvement in cough outcomes (end of trial or change in cough scores). Significant differences were only found in sensitivity analysis. A significant improvement in change of cough scores was found in end of intervention (2-3 months) in those receiving PPI with a standardised mean difference of -0.41 (95%CI -0.75, -0.07) using GIV analysis on cross over trials. Two studies reported improvement in cough after 5 days to 2 weeks of treatment. Significant heterogeneity was found between studies using omeprazole and other PPIs.

AUTHORS' CONCLUSIONS

There is insufficient evidence to definitely conclude that GORD treatment with PPI is beneficial for cough associated with GORD in adults. The beneficial effect was only seen in sub-analysis and its effect was small. The optimal duration of such a trial of therapy to evaluate response could not be ascertained in the meta-analysis although two RCTs reported significant change by two weeks of therapy. Clinicians should be cognisant of a period (natural resolution with time) and placebo effect in studies that utilise cough as an outcome measure. Data in children are inconclusive. Future paediatric and adult studies are needed whereby studies should be double blind, randomised controlled, parallel design, using treatments for at least two months, with validated subjective and objective cough outcomes and include ascertainment of time to respond as well as assessment of acid and/or non acid reflux whilst on therapy.

Resting energy expenditure in children with inflammatory bowel disease

OBJECTIVES

There is controversy in the literature regarding the effect of inflammatory bowel disease (IBD) on resting energy expenditure (REE). In many cases this may have resulted from inappropriate adjustment of REE measurements to account for differences in body composition. This article considers how to appropriately adjust measurements of REE for differences in body composition between individuals with IBD.

PATIENTS AND METHODS

Body composition, assessed via total body potassium to yield a measure of body cell mass (BCM), and REE measurements were performed in 41 children with Crohn disease and ulcerative colitis in the Royal Children's Hospital, Brisbane, Australia. Log-log regression was used to determine the power function to which BCM should be raised to appropriately adjust REE to account for differences in body composition between children.

RESULTS

The appropriate value to "adjust" BCM was found to be 0.49, with a standard error of 0.10.

CONCLUSIONS

Clearly, there is a need to adjust for differences in body composition, or at the very least body weight, in metabolic studies in children with IBD. We suggest that raising BCM to the power of 0.5 is both a numerically convenient and a statistically valid way of achieving this aim. Under circumstances in which the measurement of BCM is not available, raising body weight to the power of 0.5 remains appropriate. The important issue of whether REE is changed in cases of IBD can then be appropriately addressed.

A study of dysphagia symptoms and esophageal body function in children undergoing anti-reflux surgery

BACKGROUND

The role of high-resolution esophageal impedance manometry (HRIM) for establishing risk for dysphagia after anti-reflux surgery is unclear. We conducted a prospective study of children with primary gastroesophageal reflux (GER) disease, for whom symptoms of dysphagia were determined pre-operatively and then post-operatively and we examined for features that may predict post-operative dysphagia.

METHODS

Thirteen children (aged 6.8-15.5 years) undergoing work-up prior to 360o Nissen fundoplication were included in the study. A dysphagia score assessed symptoms at pre-operative study and post-operatively (mean 1.4 years). A HRIM procedure recorded 5-ml liquid, 5-ml viscous and 2-cm solid boluses. We assessed esophageal motility, esophago-gastric junction (EGJ) morphology, EGJ contractility and pressure-flow variables indicative of bolus distension pressures and bolus clearance pressures. A composite pressure-flow index score was also derived.

RESULTS

Pre-operative pressure-flow index was positively correlated with post-operative dysphagia score (viscous bolus r = 0.771, p < 0.005). Of three variables that comprise the pressure-flow index, the ramp pressure measured during bolus clearance was the main driver of the effect seen (viscous bolus r = 0.819, p < 0.005).

CONCLUSIONS

In order to mitigate symptoms in relation to anti-reflux surgery, dysphagia symptoms and esophageal function need to be pre-operatively assessed. In patients with normal motility, an elevated pressure-flow index may predict post-operative dysphagia.

Visual and automated differential leukocyte counts. A comparison study of three instruments

The authors compared referee (senior author) microscopic counts, microscopic counts by several technologists, and counts obtained with two pattern-recognition leukocyte classifiers, (1) Larc and (2) Hematrak, and a cytochemical automated method for leukocyte counting, (3) Hermalog D, using samples from (1) a random patient population, (2) a selected abnormal patient population, and (3) healthy individuals. All instruments showed good accuracy and flagged abnormal results for review. Variability in pattern-recognition counts was found to be due mainly to the distribution of the cells on prepared blood smears. The Larc classifier was found to be very sensitive to minor alterations in the cytoplasm or nucleus, and rejected a number of slides. The Hemalog D showed the greatest precision. The method of preparation of slides would be a major decision factor in selecting one pattern-recognition instrument over another.

Effect of a full and empty bladder on radiation dose to the uterus, ovaries and bladder from lumbar spine CT and X-ray examinations

This is a quantitative study of the effect of a full and empty bladder on the position of the uterus, ovaries and bladder relative to the lumbar spine. Data are used to estimate the difference in radiation dose to these organs from performing a lumbar spine CT investigation or a lateral lumbar spine radiograph with a full bladder compared with an empty bladder. 12 women of child-bearing age underwent pelvic magnetic resonance scans with full and empty bladders. The positions of the uterus, ovaries and bladder were matched with the radiation dose distribution that would have occurred either side of the inferior boundary of the CT scan volume and the lateral lumbar spine radiograph. These radiation dose profiles were measured on phantoms using a combination of ionization chambers and thermoluminescent dosemeters. When the bladder was emptied, the mean position of the endometrial cavity fundal tip moved from 4.1 cm to 6.1 cm inferior to the centre of the L5/S1 disc space, and from 0.87 cm to 1.12 cm anterior to the centre of the L5/S1 disc space. This movement on micturation would have reduced the mean dose to the uterine internal fundal tip during a pelvic CT scan from 6.8 mGy to 3.9 mGy, which represents a mean reduction of 43% (range 12-67%). The mean dose from a lateral lumbar spine examination would have been reduced from 197 microGy to 126 microGy. The change in ovary position results in the mean ovary dose being reduced by 48% for the lumbar spine CT scan and by 43%) for a lateral lumbar spine radiograph. When the bladder was emptied, the average position of the bladder wall moved from 7.2 cm to 10.3 cm inferior to the L5/S1 disc space. This change in bladder position reduces the mean dose to the wall of a full bladder from 5.7 mGy for a CT scan and 114 microGy for a lumbar spine radiograph to 2.2 mGy and 42 microGy, respectively, for an empty bladder.

Interobserver variability in antroduodenal manometry

Interobserver variability affects investigations involving assessment of complex visual data, such as histopathology, radiology and motility. This study assessed interobserver variation for interpretation of antroduodenal manometry (ADM), as this has not been previously investigated. Thirty-five ADM recordings from children aged 0.3-18 years were independently evaluated by five experienced paediatric gastroenterologists who were blinded to cases' clinical histories. Intra-class correlation (ICC) was analysed for detection and measurement of phase three of the migrating motor complex (MMC) and Cohen's kappa statistic was calculated between observer pairs for detection of specific motility features and final diagnosis. Observers were unanimous on the differentiation of normal and abnormal motility in 63% of cases. There was excellent interobserver agreement for the number of phase three of the MMC in fasting (ICC = 0.82, P < 0.0001) and for measurements of phase three of the MMC (ICC = 0.9999, P < 0.0001). Detection of other normal and abnormal motility patterns varied more. Objective findings such as the presence of phase three of the MMC correlated more closely than findings that involved the integration of several variables, such as final diagnosis. However, these data overall indicate that agreement between expert observers for the distinction of normal and abnormal antroduodenal motility compares favourably with other standard medical assessments.

Your PC can enhance staff and patient education

Obtaining education materials for both staff and patients can be expensive. Tracking staff certification requirements and available references for individual units can be time consuming and awkward. Using a regular home personal computer and inexpensive software applications, the staff nurse, educator, and manager can produce quality education products, maintain records, and graph representation of administrative trends.