HSD3B1 is an oxysterol 3β-hydroxysteroid dehydrogenase in human placenta

Most biologically active oxysterols have a 3β-hydroxy-5-ene function in the ring system with an additional site of oxidation at C-7 or on the side-chain. In blood plasma oxysterols with a 7α-hydroxy group are also observed with the alternative 3-oxo-4-ene function in the ring system formed by ubiquitously expressed 3β-hydroxy-Δ⁵-C₂₇-steroid oxidoreductase Δ⁵-isomerase, HSD3B7. However, oxysterols without a 7α-hydroxy group are not substrates for HSD3B7 and are not usually observed with the 3-oxo-4-ene function. Here we report the unexpected identification of oxysterols in plasma derived from umbilical cord blood and blood from pregnant women taken before delivery at 37+ weeks of gestation, of side-chain oxysterols with a 3-oxo-4-ene function but no 7α-hydroxy group. These 3-oxo-4-ene oxysterols were also identified in placenta, leading to the hypothesis that they may be formed by a previously unrecognized 3β-hydroxy-Δ⁵-C₂₇-steroid oxidoreductase Δ⁵-isomerase activity of HSD3B1, an enzyme which is highly expressed in placenta. Proof-of-principle experiments confirmed that HSD3B1 has this activity. We speculate that HSD3B1 in placenta is the source of the unexpected 3-oxo-4-ene oxysterols in cord and pregnant women's plasma and may have a role in controlling the abundance of biologically active oxysterols delivered to the fetus.

The path to evidence-based guidelines for food insecurity during pregnancy

Background

Food insecurity has negative health implications during and after pregnancy, however, identifying and then assisting women who are food insecure is complex. Successful screening programs are often embedded in practice guidelines that include referral and treatment guidance. Screening for food insecurity is vital to address food insecurity, however, it is not present in Australia, nor are there any guidelines for healthcare settings. This presentation will describe the steps taken to gather evidence to inform the development of practice guidelines.

Methods

The creation of practice guidelines for screening and responding to the needs of food insecure pregnant women was informed by 1) qualitative interviews with food insecure pregnant women, and 2) qualitative interviews with clinicians about their experiences of assisting hungry and food insecure pregnant women, 3) quantitative research with a cross-section of pregnant women about their experiences managing their food supply, 4) a systematic review describing the existing interventions addressing food insecurity during pregnancy, and 5) a modified Delphi to gather the opinions of experts on the best ways to address food insecurity in pregnancy.

Results

This work highlight the potential effectiveness of a food insecurity screening tool in the antenatal setting, the readiness of clinicians to respond to this need, the breadth and depth of current interventions to address food insecurity, and the opinions of experts on how this issue needs to be addressed. The combined impact of these 5 studies is the identification of a number of responces to food insecurity and hunger during pregnancy.

Conclusions

Given the lack of screening, standard care, and treatment of food insecurity in a clinical setting in Australia, it is essentail that guidelines are created that standardise patient care and control costs through efficient use of health care resources.

Key messages

• Food insecurity during pregnancy has significant implications for both mother and baby.

• Creating supportive evidence-based mechanisms to address food insecurity will lead to positive outcomes.

POS0393 ASSOCIATION BETWEEN GENETICALLY PREDICTED EXPRESSION OF TPMT AND AZATHIOPRINE ADVERSE EVENTS IN PATIENTS WITH INFLAMMATORY CONDITIONS

Background

Azathioprine is a widely used immunosuppressant for the treatment of inflammatory conditions such as systemic lupus erythematosus (SLE), systemic vasculitis, dermatomyositis, and inflammatory bowel disease. However, its use is often limited by myelotoxicity. Variants in the gene encoding thiopurine-S-methyltransferase (TPMT), an enzyme in the metabolic pathway of azathioprine, increase the risk for myelotoxicity1. We know little about the relationship between the genetically predicted expression of TPMT and side effects of azathioprine.

Objectives

To examine whether genetically predicted expression of TPMT in liver tissue is associated with azathioprine adverse effects.

Methods

We assembled a retrospective cohort of new users taking azathioprine for inflammatory conditions at a tertiary care center. We performed genotyping with Illumina Infinium Expanded Multi-Ethnic Genotyping Array plus custom content data, and we then used Michigan Imputation servers for genetic imputation and PrediXcan models trained with GTEx/Genotype-Tissue Expression Project version 8 data to impute TPMT expression in liver tissue. We prespecified nine groups of phecodes (comprised of ICD9 and ICD10 codes) corresponding to known adverse effects of azathioprine. We then tested the association between the predicted expression of TPMT and these adverse events; for outcomes significant in the Wilcoxon ranksum tests (p<0.05), each case was reviewed in clinical records for confirmation. Finally, we grouped the predicted expression of TPMT in liver tissue into tertiles and conducted logistic regressions to assess the associations between predicted expression and side effects. We conducted a sensitivity analysis restricted to patients with EHR-reported White race.

Results

The cohort included 1034 patients (Table 1). Phecodes for 3 side effects—leukopenia (n=29), skin cancer (n=13), and rash (n=52)—were identified as associated with predicted TPMT expression in liver tissue. Of these, cases of side effects attributed to azathioprine were validated by chart review: leukopenia (96.6%; n=28), skin cancer (92.3%; n=12), and rash (9.6%; n=5) and used for analysis. When assessed by tertile of predicted TPMT expression, patients in the highest tertile had lower odds of having leukopenia (OR=0.35, 95%CI: 0.12-0.98, p=0.045) and a trend towards higher odds for skin cancer, but the number of cases was small (OR=3.56, 95%CI: 0.73-17.27, p=0.115). Confirmed cases of rash attributed to azathioprine were too few for meaningful analysis. We found similar results when restricted to patients with reported White race.

Table 1.

Characteristics of patients by TPMT expression

Lowest TertileMiddle TertileHighest TertileN=345N=345N=344Female sex, n (%)228 (66.1)244 (70.7)238 (69.2)EHR-reported White race, n (%)306 (88.7)293 (84.9)290 (84.3)Age, median [IQR]42 [29-58]43 [30-55]46 [30-56]Indication, n (%)Systemic lupus erythematosus38 (11.0)42 (12.2)38 (11.0)Inflammatory bowel disease191 (55.3)185 (53.6)190 (55.2)Other connective tissue disorder/autoimmune92 (26.7)96 (27.8)100 (29.1)Other24 (7.0)22 (6.4)16 (4.7)Verified leukopenia attributed to azathioprine, n (%)14 (4.1)9 (2.6)5 (1.5)Verified skin cancer attributed to azathioprine, n (%)2 (0.6)3 (0.9)7 (2.0)Verified rash attributed to azathioprine, n (%)2 (0.6)3 (0.9)0 (0)

Conclusion

This analysis suggests that PrediXcan may be useful for examining the association between gene expression and side effects of medications. Moreover, this approach successfully identified leukopenia as a side effect associated with predicted TPMT expression.

Acknowledgements

None to declare.

Disclosure of Interests

None declared.

POS1444 FLT1 AND EPHB2 ARE NOVEL GENETIC MARKERS ASSOCIATED WITH PANCREATITIS IN PATIENTS TAKING AZATHIOPRINE FOR IMMUNE-MEDIATED CONDITIONS: INTEGRATING GENOME- AND TRANSCRIPTOME-WIDE ASSOCIATION STUDIES

Background

Azathioprine (AZA) is a thiopurine immunosuppressant medication used to treat a variety of immune-mediated diseases. Unfortunately, its use is limited by adverse effects. Pancreatitis, a potentially severe, life-threatening side effect is independent of dose and necessitates AZA discontinuation given the high risk of recurrent pancreatitis with continued use or re-challenge. The mechanisms driving pancreatitis are unclear. While classic thiopurine-induced acute pancreatitis (TIAP) has been associated with HLA haplotypes, most patients taking AZA and presenting with pancreatitis do not fulfill the stringent criteria for TIAP.

Objectives

To identify genetic risk factors for pancreatitis in patients taking azathioprine for immune-mediated conditions.

Methods

Using a biobank linked to electronic health records (EHR) from a tertiary center, we identified new users of AZA. Patients were excluded if the primary indication for AZA was organ transplant or if there was a history of pancreatitis prior to AZA use. The analysis was restricted to patients with EHR-reported race as White due to insufficient case counts for the non-White group. We then identified patients with amylase or lipase values that exceeded twice the upper limit of normal (“>2x ULN”) or with ICD-9/ICD-10 codes for acute pancreatitis. Each record was manually reviewed to confirm the timing of AZA use in relation to laboratory derangements or ICD coding, as well as to further classify patients into three increasingly strict, but not exclusive categories: 1) pancreatic injury (amylase or lipase >2x ULN); 2) acute pancreatitis1, or 3) TIAP2. We completed genotyping with Illumina Infinium Expanded Multi-Ethnic Genotyping Array plus custom content data, employed Michigan Imputation servers for genetic imputation, and used PrediXcan (GTEx v8) to impute gene expression. We then conducted genome-wide association and transcriptome-wide association studies (GWAS, TWAS). Acknowledging the relatively small overall cohort, and possible imbalance of cases vs controls, we used the Firth logistic regression method, which is a penalized likelihood-based method.

Results

We studied 2127 AZA users (35.4% male; mean 44.5+/-17.2 years). The median AZA dose was 100mg/day (IQR: 50-125mg/day). Rheumatologic conditions (56.9%) and inflammatory bowel disease (40.4%) comprised the most common primary indications for AZA. Pancreatic injury, pancreatitis, and TIAP were diagnosed in 42 (2.0%), 16 (0.8%), and 9 (0.4%) patients, respectively. GWAS identified several significantly associated genes, many with overlapping TWAS findings in the pancreas and liver (Figure 1). From these, the two protein-encoding genes Fms Related Receptor Tyrosine Kinase-1 (FLT1) and Ephrin type-B receptor-2 (EPHB2) overlapped in two or more pancreatitis phenotypes in the TWAS and GWAS, respectively. EPHB2 was associated with a 8.6-fold (P=1.84 x 10-8) and a 31.4-fold (P=2.87x 10-8) higher likelihood of pancreatic injury and TIAP, respectively.

Figure 1.

Conclusion

FLT1—a gene that encodes a receptor tyrosine kinase and is a member of the vascular endothelial growth factor receptor (VEGFR) family—and EPHB2—a gene that encodes a member of the Eph receptor family, which is the largest subgroup of the receptor tyrosine kinase family—are novel genetic markers associated with pancreatitis in patients taking AZA. VEGF can potentiate inflammation and the pancreas microenvironment is known to promote VEGF expression, which has been linked to pancreatic cancer development; anti-VEGF treatments have been investigated both for mitigating inflammation and also anti-pancreatic cancer treatment. Future studies validating our findings in AZA-induced pancreatitis are warranted.

References

[1]Crockett et al. Gastroenterology (2018). 154(4):1096-1101.

[2]Heap et al. Nature Genetics (2014). 46:1131-1134

Disclosure of Interests

Shailja Shah Consultant of: ad hoc consultant for Phathom pharmaceuticals, Tyler Reese: None declared, Jacy Zanussi: None declared, Alyson Dickson: None declared, Laura Daniel: None declared, Ran Tao: None declared, Tyne Miller-Fleming: None declared, Peter Straub: None declared, Adriana Hung: None declared, Puran Nepal: None declared, Wei-Qi Wei: None declared, Elizabeth Phillips: None declared, Nancy Cox: None declared, Charles M. Stein: None declared, QiPeng Feng: None declared, Cecilia P. Chung: None declared

Public Health Impacts of Underemployment and Unemployment in the United States: Exploring Perceptions, Gaps and Opportunities

BACKGROUND

Unemployment, underemployment, and the quality of work are national occupational health risk factors that drive critical national problems; however, to date, there have been no systematic efforts to document the public health impact of this situation.

METHODS

An environmental scan was conducted to explore the root causes and health impacts of underemployment and unemployment and highlight multilevel perspectives and factors in the landscape of underemployment and unemployment.

METHODS

included a review of gray literature and research literature, followed by key informant interviews with nine organizational representatives in employment research and policy, workforce development, and industry to assess perceived needs and gaps in practice.

RESULTS

Evidence highlights the complex nature of underemployment and unemployment, with multiple macro-level underlying drivers, including the changing nature of work, a dynamic labor market, inadequate enforcement of labor protection standards, declining unions, wage depression, and weak political will interacting with multiple social determinants of health. Empirical literature on unemployment and physical, mental, and psychological well-being, substance abuse, depression in young adults, and suicides is quite extensive; however, there are limited data on the impacts of underemployment on worker health and well-being. Additionally, organizations do not routinely consider health outcomes as they relate to their work in workforce or policy development.

DISCUSSION AND CONCLUSIONS

Several gaps in data and research will need to be addressed in order to assess the full magnitude of the public health burden of underemployment and unemployment. Public health needs to champion a research and practice agenda in partnership with multisector stakeholders to illuminate the role of employment quality and status in closing the gap on health inequities, and to integrate workforce health and well-being into labor and economic development agendas across government agencies and industry.

Metabolism of Non-Enzymatically Derived Oxysterols: Clues from sterol metabolic disorders

Cholestane-3β,5α,6β-triol (3β,5α,6β-triol) is formed from cholestan-5,6-epoxide (5,6-EC) in a reaction catalysed by cholesterol epoxide hydrolase, following formation of 5,6-EC through free radical oxidation of cholesterol. 7-Oxocholesterol (7-OC) and 7β-hydroxycholesterol (7β-HC) can also be formed by free radical oxidation of cholesterol. Here we investigate how 3β,5α,6β-triol, 7-OC and 7β-HC are metabolised to bile acids. We show, by monitoring oxysterol metabolites in plasma samples rich in 3β,5α,6β-triol, 7-OC and 7β-HC, that these three oxysterols fall into novel branches of the acidic pathway of bile acid biosynthesis becoming (25R)26-hydroxylated then carboxylated, 24-hydroxylated and side-chain shortened to give the final products 3β,5α,6β-trihydroxycholanoic, 3β-hydroxy-7-oxochol-5-enoic and 3β,7β-dihydroxychol-5-enoic acids, respectively. The intermediates in these pathways may be causative of some phenotypical features of, and/or have diagnostic value for, the lysosomal storage diseases, Niemann Pick types C and B and lysosomal acid lipase deficiency. Free radical derived oxysterols are metabolised in human to unusual bile acids via novel branches of the acidic pathway, intermediates in these pathways are observed in plasma.

Understanding the relationship between pet owners and their companion animals as a key context for antimicrobial resistance-related behaviours: an interpretative phenomenological analysis

Objectives: Drivers of antimicrobial resistance (AMR) are diffuse and complex including a range of interspecies behaviours between pet owners and their animals. We employed interpretative phenomenological analysis (IPA) to explore the relationship between pet owners and their companion animals in relation to AMR. Design: Cross sectional, qualitative study. Methods: Semi-structured interviews were conducted with twenty-three British pet owners, transcribed verbatim and subjected to Interpretative Phenomenological Analysis (IPA). Results: Three, inter-related Superordinate themes are presented 1) 'They're my fur babies': unconditional love and anthropomorphism; 2) 'They share everything with you': affection and transmission behaviours; and 3) 'We would err on the side of caution': decision making and antibiotic use'. Conclusions: Affectionate behaviours between companion animals and their owners pose a risk for AMR transmission but they are so deeply treasured that they are unlikely to be amenable to change. In contrast, the promotion of appropriate antibiotic stewardship for pet owners and vets may offer a viable pathway for intervention development, benefitting from synergies with other interventions that target prescribers.

Exploring the behavioural drivers of veterinary surgeon antibiotic prescribing: a qualitative study of companion animal veterinary surgeons in the UK

Background

Multi-drug resistant bacteria are an increasing concern in both human and veterinary medicine. Inappropriate prescribing and use of antibiotics within veterinary medicine may be a contributory factor to antimicrobial resistance (AMR). The ‘One Health’ Initiative aims to work across species and environments to reduce AMR, however; little is currently known about the factors which influence antibiotic prescribing among veterinary surgeons in companion animal practice.

This paper reports on qualitative data analysis of interviews with veterinary surgeons whose practice partially or wholly focuses on companion animals (N = 16). The objective of the research was to explore the drivers of companion animal veterinary surgeons’ antibiotic prescribing behaviours. The veterinary surgeons interviewed were all practising within the UK (England (n = 4), Scotland (n = 11), Northern Ireland (n = 1)). A behavioural thematic analysis of the data was undertaken, which identified barriers and facilitators to specific prescribing-related behaviours.

Results

Five components of prescribing behaviours were identified: 1) confirming clinical need for antibiotics; 2) responding to clients; 3) confirming diagnosis; 4) determining dose, duration and type of antibiotic; and 5) preventing infection around surgery (with attendant appropriate and inappropriate antibiotic prescribing behaviours). Barriers to appropriate prescribing identified include: business, diagnostic, fear, habitual practice and pharmaceutical factors. Facilitators include: AMR awareness, infection prevention, professional learning and regulation and government factors.

Conclusion

This paper uses a behavioural lens to examine drivers which are an influence on veterinary surgeons’ prescribing behaviours. The paper contributes new understandings about factors which influence antibiotic prescribing behaviours among companion animal veterinary surgeons. This analysis provides evidence to inform future interventions, which are focused on changing prescribing behaviours, in order to address the pressing public health concern of AMR.

The shame of fat shaming in public health: moving past racism to embrace indigenous solutions

OBJECTIVES

The aim of this article is to explore perceptions of weight and racism towards Māori, as an indigenous group, and the association between the two. We then propose indigenous solutions as pathways out of fat shaming.

STUDY DESIGN

This is a conceptual article supported by a review of literature in the fields of weight stigma, racism and indigenous (Māori) health.

METHODS

This article is taken from the perspective of three researchers involved in Māori health research, studies on institutional and societal racism and critical research on weight stigma and the weight loss industry. Indigenous peoples in developed nations are more likely to be overweight, obese and disproportionately affected by the comorbidities and physical disorders associated with weight when compared with their counterparts. Beyond the physical ailments are a variety of psychological, emotional and social issues, which are associated with being 'fat' and/or overweight and/or from subsequent stigmatisation.

RESULTS

Long before this world's populations reached the current alarming level of obesity, indigenous peoples in colonised countries were stigmatised because of the colour of their skin, their beliefs and their culture. Stigma is nothing new to indigenous peoples, and so when Māori, or any other indigenous groups are told they are fat and less productive (or moral) because of 'fatness', there is no surprise because they have been told the same thing (albeit for a different reason) for generations. Considering the relatively high proportion of indigenous people in New Zealand, North America and beyond who do not fit the 'recommended weight range', the justification for racist sentiment is seemingly strengthened.

CONCLUSIONS

A weight loss-centred approach to health has not improved the health of indigenous people. Initiatives that draw on, or are underpinned by local, traditional knowledge are more relevant for indigenous peoples and could lead to better health outcomes for these groups.

Barriers and enablers to meticillin-resistant Staphylococcus aureus admission screening in hospitals: a mixed-methods study

BACKGROUND

To reduce the risk of transmission of meticillin-resistant Staphylococcus aureus (MRSA), international guidelines recommend admission screening to identify hospital patients at risk of colonization. However, routine monitoring indicates that optimum screening compliance levels are not always achieved. In order to enhance compliance, we must better understand those factors which influence staff screening behaviours.

AIM

To identify factors which influence staff compliance with hospital MRSA screening policies.

METHODS

A sequential two-stage mixed-methods design applied constructs from normalization process theory and the theoretical domains framework to guide data collection and analysis. Initial qualitative findings informed subsequent development of a national cross-sectional survey of nursing staff (N = 450). Multiple regression modelling identified which barriers and enablers best predict staff compliance.

FINDINGS

Three factors were significant in predicting optimum (>90%) compliance with MRSA screening: having MRSA screening routinized within the admission process; category of clinical area; feedback of MRSA screening compliance within the clinical area. Integration of data-sets indicated that organizational systems which 'make doing the right thing easy' influence compliance, as does local ward culture. Embedded values and beliefs regarding the relative (de)prioritization of MRSA screening are important.

CONCLUSION

To our knowledge, this is the first study to provide original evidence of barriers and enablers to MRSA screening, applying both sociological and psychological theory. As antimicrobial resistance is a global health concern, these findings have international relevance for screening programmes. Future policy recommendations or behaviour change interventions, based on the insights presented here, could have significant impact upon improving screening compliance.

Negotiating boundaries of care: an interpretative phenomenological analysis of the relational conflicts surrounding home mechanical ventilation following traumatic spinal cord injury

Objectives: The aim of this study is to explore the phenomena of mechanical ventilation following traumatic spinal cord injury from three simultaneous perspectives; patients who require full-time mechanical ventilation (n = 8), their informal family carers (n = 8) and their formal carers (n = 11). We focus upon the intra and inter- personal challenges of establishing boundaries within the triad. Design: Qualitative study. Methods: Semi-structured interviews were transcribed verbatim and analysed using interpretative phenomenological analysis (IPA). In order to encapsulate the inter-subjective, multi-dimensional and relational aspects of the experience, we focussed on recurrent themes which were independently reported across all three participant groups. Results: One major inter-connected recurrent theme was identified: 1) 'Negotiating boundaries of care and finding a "fit"'. It centres around establishing a 'line', or a boundary, which was imperative for retaining a sense of independence (for patients), a sense of home and privacy (for informal carers) and difficulties balancing complex care provision with the needs of family members so as not to cross that 'line' (for formal carers). Conclusions: The findings highlight the need for focussing on a 'fit' within the triad, balancing boundaries of care in order to establish a productive, satisfactory psycho-social environment for all three participant groups to live and/or work within. Recommendations for both future care provision and future research are suggested.

Identification of unusual oxysterols and bile acids with 7-oxo or 3β,5α,6β-trihydroxy functions in human plasma by charge-tagging mass spectrometry with multistage fragmentation

7-Oxocholesterol (7-OC), 5,6-epoxycholesterol (5,6-EC), and its hydrolysis product cholestane-3β,5α,6β-triol (3β,5α,6β-triol) are normally minor oxysterols in human samples; however, in disease, their levels may be greatly elevated. This is the case in plasma from patients suffering from some lysosomal storage disorders, e.g., Niemann-Pick disease type C, or the inborn errors of sterol metabolism, e.g., Smith-Lemli-Opitz syndrome and cerebrotendinous xanthomatosis. A complication in the analysis of 7-OC and 5,6-EC is that they can also be formed ex vivo from cholesterol during sample handling in air, causing confusion with molecules formed in vivo. When formed endogenously, 7-OC, 5,6-EC, and 3β,5α,6β-triol can be converted to bile acids. Here, we describe methodology based on chemical derivatization and LC/MS with multistage fragmentation (MSⁿ) to identify the necessary intermediates in the conversion of 7-OC to 3β-hydroxy-7-oxochol-5-enoic acid and 5,6-EC and 3β,5α,6β-triol to 3β,5α,6β-trihydroxycholanoic acid. Identification of intermediate metabolites is facilitated by their unusual MSⁿ fragmentation patterns. Semiquantitative measurements are possible, but absolute values await the synthesis of isotope-labeled standards.

Long-Range Changes in Neurolysin Dynamics Upon Inhibitor Binding

Crystal structures of neurolysin, a zinc metallopeptidase, do not show a significant conformational change upon the binding of an allosteric inhibitor. Neurolysin has a deep channel where it hydrolyzes a short neuropeptide neurotensin to create inactive fragments and thus controls its level in the tissue. Neurolysin is of interest as a therapeutic target since changes in neurotensin level have been implicated in cardiovascular disorders, neurological disorders, and cancer, and inhibitors of neurolysin have been developed. An understanding of the dynamical and structural differences between apo and inhibitor-bound neurolysin will aid in further design of potent inhibitors and activators. For this purpose, we performed several molecular dynamics (MD) simulations for both apo and inhibitor-bound neurolysin. A machine learning method (Linear Discriminant Analysis) is applied to reveal differences between the apo and inhibitor-bound ensembles in an automated way, and large differences are observed on residues that are far from both the active site and the inhibitor binding site. The effects of inhibitor binding on the collective motions of neurolysin are extensively analyzed and compared using both Principal Component Analysis and Elastic Network Model calculations. We find that inhibitor binding induces additional low-frequency motions that are not observed in the apo form. ENM also reveals changes in inter- and intradomain communication upon binding. Furthermore, differences are observed in the inhibitor-bound neurolysin contact network that are far from the active site, revealing long-range allosteric behavior. This study also provides insight into the allosteric modulation of other neuropeptidases with similar folds.

Charge-tagging liquid chromatography-mass spectrometry methodology targeting oxysterol diastereoisomers

•

EADSA and LC–MS allows the differentiation of sterol diastereoisomers.

•

24S- and 24R-hydroxycholesterol are present in human plasma.

•

Four diastereoisomers of 3β,7-dihydroxycholest-5-enoic acid are found in human plasma.

•

3β,7α- and 3β,7β-dihydroxychol-5-enoic acids are found in human plasma.

•

7α- and 7β- epimers give distinguishable MS³ spectra.

The introduction of a hydroxy group to the cholesterol skeleton introduces not only the possibility for positional isomers but also diastereoisomers, where two or more isomers have different configurations at one or more of the stereocentres but are not mirror images. The differentiation of diastereoisomers is important as differing isomers can have differing biochemical properties and are formed via different biochemical pathways. Separation of diasterioisomers is not always easy by chromatographic methods Here we demonstrate, by application of charge-tagging and derivatisation with the Girard P reagent, the separation and detection of biologically relevant diastereoisomers using liquid chromatography − mass spectrometry with multistage fragmentation.

Alternative ileal flap for bladder augmentation if mesentery is short

PURPOSE

To date the clam ileocystoplasty is the preferred method of bladder augmentation in children when the urodynamic problem is non-compliance and/or detrusor overactivity. The key to this technique is the incision of the bladder wall deep into the pelvis down to the trigone in order to avoid a diverticulum like neobladder and to provide adequate margin for augmentation. The detubularised ileum flap therefore has to reach to the bottom of the divided bladder on a reliable vascular pedicle without significant tension. A short ileal mesentery caused by previous surgery, peritonitis, peritoneal dialysis or ventriculo-peritoneal shunt may complicate surgery and compromise outcome. We hypothesized we can rely on the communication of the intramural vessels within the intestine and can detubularise the ileum adjacent to the mesentery rather than along the antimesenteric line and this could be combined with ligation of some vasa recta (VR) in order to create alternative ileum flaps, which reach further into the pelvis. Our aim was to assess the viability of the alternative flaps detubularised along the paramesenteric line and measure how many VR could be sacrificed beyond the tertiary arcades.

MATERIALS AND METHODS

After ethical approval adjacent ileal segments were detubulirased along the antimesenteric line (Group 1) and along the paramesenteric line (Group 2) in 5 minipigs in general anaesthesia. Ligation of 0,1,2,3 and 4 VR has been performed starting from the free end of the segments. The length of the ileal flaps was recorded. The microcirculation of flap edges was detected by in vivo microscopy using orthogonal polarising spectral imaging (Cytoscan A/R Cytometrics, PA, USA). Clam ileocystoplasty was performed with the ileum detubularised along the paramesenteric line without ligation of VR. Specimens of the augmented bladder were obtained after 4 weeks and stained with Hematoxilin + Eosin.

RESULTS

No alteration in capillary red blood cell velocity (RBCV) and perfusion rate (PR) was observed after paramesenteric detubularisation. The flaps in Group 2 reached 20.25 ± 0.5 mm longer vs.

CONTROL

This is 98% of the mean bowel width (20.5 ± 0.57 mm) measured in the animals. Ligation of each VR further increased the length of both flaps (mean: 10.59 ± 3.18 mm) however ligation of more than 2 VR gradually decreased the microcirculation in both groups. All animals augmented with alternative flap survived, there was no urine leak or suture break down. Histology confirmed viable bowel flaps.

CONCLUSION

Paramesenteric detubularisation of the ileum is fully tolerated and results in longer reaching ileal flap vs.

CONTROL

Only limited ligation of VR is tolerated.

DISCUSSION

This study showed the first time that clam ileocystoplasty is feasible with ileal flap detubularised along the paramesenteric line. The use of the animal model and the relative short postoperative observation are the main limitations of this study.

The effect of luminal content and rate of occlusion on the interpretation of colonic manometry

BACKGROUND

Manometry is commonly used for diagnosis of esophageal and anorectal motility disorders. In the colon, manometry is a useful tool, but clinical application remains uncertain. This uncertainty is partly based on the belief that manometry cannot reliably detect non-occluding colonic contractions and, therefore, cannot identify reliable markers of dysmotility. This study tests the ability of manometry to record pressure signals in response to non-lumen-occluding changes in diameter, at different rates of wall movement and with content of different viscosities.

METHODS

A numerical model was built to investigate pressure changes caused by localized, non-lumen-occluding reductions in diameter, similar to those caused by contraction of the gut wall. A mechanical model, consisting of a sealed pressure vessel which could produce localized reductions in luminal diameter, was used to validate the model using luminal segments formed from; (i) natural latex; and (ii) sections of rabbit proximal colon. Fluids with viscosities ranging from 1 to 6800 mPa s(-1) and luminal contraction rates over the range 5-20 mmHg s(-1) were studied.

KEY RESULTS

Manometry recorded non-occluding reductions in diameter, provided that they occurred with sufficiently viscous content. The measured signal was linearly dependent on the rate of reduction in luminal diameter and also increased with increasing viscosity of content (R(2) = 0.62 and 0.96 for 880 and 1760 mPa s(-1), respectively).

CONCLUSIONS & INFERENCES

Manometry reliably registers non-occluding contractions in the presence of viscous content, and is therefore a viable tool for measuring colonic motility. Interpretation of colonic manometric data, and definitions based on manometric results, must consider the viscosity of luminal content.

Neuropsychological functioning, illness perception, mood and quality of life in chronic fatigue syndrome, autoimmune thyroid disease and healthy participants

BACKGROUND

This study attempted to longitudinally investigate neuropsychological function, illness representations, self-esteem, mood and quality of life (QoL) in individuals with chronic fatigue syndrome (CFS) and compared them with both healthy participants and a clinical comparison group of individuals with autoimmune thyroid disease (AITD).

METHOD

Neuropsychological evaluation was administered at two time points, five weeks apart. Twenty-one individuals with CFS, 20 individuals with AITD and 21 healthy participants were matched for age, pre-morbid intelligence, education level and socio-economic status (SES). All groups also completed measures of illness perceptions, mood, self-esteem and QoL at both time points.

RESULTS

The CFS group showed significantly greater impairment on measures of immediate and delayed memory, attention and visuo-constructional ability, and reported significantly higher levels of anxiety and depression. After controlling for the effects of mood, the CFS group still demonstrated significant impairment in attention. The CFS group also reported significantly lower self-reported QoL than the AITD and healthy participants. In terms of illness perceptions, the AITD group believed that their condition would last longer, that they had more treatment control over their condition, and reported less concern than the CFS group.

CONCLUSIONS

These results suggest that the primary cognitive impairment in CFS is attention and that this is not secondary to affective status. The lower treatment control perceptions and greater illness concerns that CFS patients report may be causally related to their affective status.

Uro-genital bleeding in pre-menarcheal girls: dilemmas of child abuse

Uro-genital bleeding in pre-menarcheal girls always raises concerns regarding child abuse. There are serious social issues involved; however, before labeling it as sexual abuse, all efforts must be made to rule out an organic pathology. We recently encountered two young girls of Afro-Caribbean origin who presented with vaginal bleeding with concerns from referring physicians about child/sexual abuse. On examination both had a rare condition of urethral prolapse. One of them underwent four-quadrant excision and the other was treated conservatively with urethral catherization.

Review of systematic reviews on acute procedural pain in children in the hospital setting

BACKGROUND

Acute pain is a common experience for hospitalized children. Despite mounting research on treatments for acute procedure-related pain, it remains inadequately treated.

OBJECTIVE

To critically appraise all systematic reviews on the effectiveness of acute procedure-related pain management in hospitalized children.

METHODS

Published systematic reviews and meta-analyses on pharmacological and nonpharmacological management of acute procedure-related pain in hospitalized children aged one to 18 years were evaluated. Electronic searches were conducted in the Cochrane Database of Systematic Reviews, Medline, EMBASE, the Cumulative Index to Nursing and Allied Health Literature and PsycINFO. Two reviewers independently selected articles for review and assessed their quality using a validated seven-point quality assessment measure. Any disagreements were resolved by a third reviewer.

RESULTS

Of 1469 published articles on interventions for acute pain in hospitalized children, eight systematic reviews met the inclusion criteria and were included in the analysis. However, only five of these reviews were of high quality. Critical appraisal of pharmacological pain interventions indicated that amethocaine was superior to EMLA (AstraZeneca Canada Inc) for reducing needle pain. Distraction and hypnosis were nonpharmacological interventions effective for management of acute procedure-related pain in hospitalized children.

CONCLUSIONS

There is growing evidence of rigorous evaluations of both pharmacological and nonpharmacological strategies for acute procedure-related pain in children; however, the evidence underlying some commonly used strategies is limited. The present review will enable the creation of a future research plan to facilitate clinical decision making and to develop clinical policy for managing acute procedure-related pain in children.

A diet high in omega-3 fatty acids does not improve or protect cognitive performance in Alzheimer’s transgenic mice

Although a number of epidemiologic studies reported that higher intake of omega-3 fatty acids (largely associated with fish consumption) is protective against Alzheimer's disease (AD), other human studies reported no such effect. Because retrospective human studies are problematic and controlled longitudinal studies over decades are impractical, the present study utilized Alzheimer's transgenic mice (Tg) in a highly controlled study to determine whether a diet high in omega-3 fatty acid, equivalent to the 13% omega-3 fatty acid diet of Greenland Eskimos, can improve cognitive performance or protect against cognitive impairment. Amyloid precursor protein (APP)-sw+PS1 double transgenic mice, as well as nontransgenic (NT) normal littermates, were given a high omega-3 supplemented diet or a standard diet from 2 through 9 months of age, with a comprehensive behavioral test battery administered during the final 6 weeks. For both Tg and NT mice, long-term n-3 supplementation resulted in cognitive performance that was no better than that of mice fed a standard diet. In NT mice, the high omega-3 diet increased cortical levels of omega-3 fatty acids while decreasing omega-6 levels. However, the high omega-3 diet had no effect on cortical fatty acid levels in Tg mice. Irrespective of diet, no correlations existed between brain omega-3 levels and cognitive performance for individual NT or Tg mice. In contrast, brain levels of omega-6 fatty acids were strongly correlated with cognitive impairment for both genotypes. Thus, elevated brain levels of omega-3 fatty acids were not relevant to cognitive function, whereas high brain levels of omega-6 were associated with impaired cognitive function. In Tg mice, the omega-3 supplemental diet did not induce significant changes in soluble/insoluble Abeta within the hippocampus, although strong correlations were evident between hippocampal Abeta(1-40) levels and cognitive impairment. While these studies involved a genetically manipulated mouse model of AD, our results suggest that diets high in omega-3 fatty acids, or use of fish oil supplements (DHA+EPA), will not protect against AD, at least in high-risk individuals. However, normal individuals conceivably could derive cognitive benefits from high omega-3 intake if it corrects an elevation in the brain level of n-6 fatty acids as a result. Alternatively, dietary fish may contain nutrients, other than DHA and EPA, that could provide some protection against AD.

Peptidergic sensory and parasympathetic fiber sprouting in the mucosa of the rat urinary bladder in a chronic model of cyclophosphamide-induced cystitis

In this study, we used a well-established animal model to investigate changes in the peptidergic and parasympathetic innervation of the bladder following chronic bladder inflammation. Adult female Sprague-Dawley rats were injected with either 70 mg/kg cyclophosphamide diluted in saline, i.p., once every 3 days or saline. After 10 days, all animals were tested for urinary frequency and number of low volume voids, as well as symptoms of spontaneous pain. At the end of 12 days, all animals were perfused with histological fixatives and the urinary bladders processed for immunofluorescence using antibodies against calcitonin gene-related peptide and the vesicular acetylcholine transporter as markers, respectively, of peptidergic primary afferent fibers and parasympathetic efferent fibers. We show that animals treated with cyclophosphamide had inflamed bladders and displayed high urinary frequency as well as some indicators of spontaneous pain, such as piloerection and a rounded-back posture. Furthermore, they had a significant increase in the density of both parasympathetic and peptidergic sensory fibers in the bladder mucosa and an increase in peptidergic sensory fibers in the detrusor muscle. Based on these results, we suggest that peripheral sprouting of parasympathetic and peptidergic fibers could be a mechanism responsible for sensitization of the bladder, leading to urinary symptoms. Since we observed that the parasympathetic and peptidergic fibers often wrapped around one another and that their varicosities were very close, these two fiber populations may be interacting with each other to lead to and maintain sensitization. Future studies are required to establish the role of this fiber sprouting in bladder symptoms.

Peptidergic sensory and parasympathetic fiber sprouting in the mucosa of the rat urinary bladder in a chronic model of cyclophosphamide-induced cystitis

In this study, we used a well-established animal model to investigate changes in the peptidergic and parasympathetic innervation of the bladder following chronic bladder inflammation. Adult female Sprague-Dawley rats were injected with either 70 mg/kg cyclophosphamide diluted in saline, i.p., once every 3 days or saline. After 10 days, all animals were tested for urinary frequency and number of low volume voids, as well as symptoms of spontaneous pain. At the end of 12 days, all animals were perfused with histological fixatives and the urinary bladders processed for immunofluorescence using antibodies against calcitonin gene-related peptide and the vesicular acetylcholine transporter as markers, respectively, of peptidergic primary afferent fibers and parasympathetic efferent fibers. We show that animals treated with cyclophosphamide had inflamed bladders and displayed high urinary frequency as well as some indicators of spontaneous pain, such as piloerection and a rounded-back posture. Furthermore, they had a significant increase in the density of both parasympathetic and peptidergic sensory fibers in the bladder mucosa and an increase in peptidergic sensory fibers in the detrusor muscle. Based on these results, we suggest that peripheral sprouting of parasympathetic and peptidergic fibers could be a mechanism responsible for sensitization of the bladder, leading to urinary symptoms. Since we observed that the parasympathetic and peptidergic fibers often wrapped around one another and that their varicosities were very close, these two fiber populations may be interacting with each other to lead to and maintain sensitization. Future studies are required to establish the role of this fiber sprouting in bladder symptoms.

Randomised trial of endoscopy with testing for Helicobacter pylori compared with non-invasive H pylori testing alone in the management of dyspepsia

OBJECTIVE

To compare the efficacy of non-invasive testing for Helicobacter pylori with that of endoscopy (plus H pylori testing) in the management of patients referred for endoscopic investigation of upper gastrointestinal symptoms.

DESIGN

Randomised controlled trial with follow up at 12 months.

SETTING

Hospital gastroenterology unit.

PARTICIPANTS

708 patients aged under 55 referred for endoscopic investigation of dyspepsia, randomised to non-invasive breath test for H pylori or endoscopy plus H pylori testing.

MAIN OUTCOME MEASURE

Glasgow dyspepsia severity score at one year. Use of medical resources, patient oriented outcomes, and safety were also assessed.

RESULTS

In 586 patients followed up at 12 months the mean change in dyspepsia score was 4.8 in the non-invasive H pylori test group and 4.6 in the endoscopy group (95% confidence interval for difference -0.7 to 0.5, P=0.69). Only 8.2% of patients followed up who were randomised to breath test alone were referred for subsequent endoscopy. The use of non-endoscopic resources was similar in the two groups. Reassurance value, concern about missed pathology, overall patient satisfaction, and quality of life were similar in the two groups. The patients found the non-invasive breath test procedure less uncomfortable and distressing than endoscopy with or without sedation. No potentially serious pathology requiring treatment other than eradication of H pylori was missed.

CONCLUSION

In this patient group, non-invasive testing for H pylori is as effective and safe as endoscopy and less uncomfortable and distressing for the patient. Non-invasive H pylori testing should be the preferred mode of investigation.

Malignant hyperthermia associated with exercise-induced rhabdomyolysis or congenital abnormalities and a novel RYR1 mutation in New Zealand and Australian pedigrees

Malignant hyperthermia (MH) is rarely associated with specific myopathies or musculoskeletal abnormalities. Three clinical investigations of MH associated with either non-specific myopathies or congenital disorders in three separate families are presented. Two of these cases also show evidence of exercise-induced rhabdomyolysis. In each case MH susceptibility was confirmed by in vitro contracture testing of quadriceps muscle. DNA sequence analysis of each kindred revealed the presence of a common novel mutation that results in an arginine401-cysteine substitution in the skeletal muscle ryanodine receptor gene (RYR1). Haplotype analysis using chromosome 19q markers indicated that the three families are likely to be unrelated, providing confirmation that the MH/central core disease region 1 of RYR1 is a mutation hot spot.

Symptomatic benefit 1-3 years after H. pylori eradication in ulcer patients: impact of gastroesophageal reflux disease

OBJECTIVES

Eradication of Helicobacter pylori (H. pylori) infection markedly reduces the recurrence of duodenal and gastric ulcers. However, there is little information regarding its efficacy in resolving dyspeptic symptoms in ulcer patients. The primary aim of this study was to assess the effect of eradicating H. pylori infection on dyspeptic symptoms in ulcer patients. The secondary aim was to identify predictors of symptomatic response to H. pylori eradication.

METHODS

A total of 97 dyspeptic patients with active duodenal and/or gastric ulceration associated with H. pylori infection and unrelated to NSAID use had the severity and character of their dyspeptic symptoms measured before and again 1-3 yr after H. pylori eradication therapy.

RESULTS

Pretreatment, the median dyspepsia score was 12 (4-16). Posttreatment, 55% of those eradicated of H. pylori had resolution of dyspepsia (score <2) compared with 18% of those not eradicated of the infection (95% CI for difference, 11-62%). Of the ulcer patients 31% had symptoms and/or endoscopic evidence of coexisting gastroesophageal reflux disease (GERD) at initial presentation and this influenced the symptomatic response to eradication of H. pylori. Of the 22 patients with heartburn or acid reflux as the predominant presenting symptom, but no endoscopic esophagitis, only 27% experienced resolution of dyspepsia after H. pylori eradication, compared with 68% of the 59 without those as predominant symptoms (95% CI for difference, 18-63%). Only one of the five patients with coexisting endoscopic esophagitis at initial presentation experienced resolution of dyspepsia after H. pylori eradication. Symptomatic benefit was unrelated to time lapsed since the infection was eradicated. Only three of 50 subjects developed de novo GERD symptoms after eradication of H. pylori, whereas 21 of 36 subjects experienced resolution of GERD symptoms after eradication of the infection.

CONCLUSIONS

A substantial proportion of ulcer patients have symptoms and/or signs of coexisting GERD at initial presentation and this reduces the symptomatic benefit from H. pylori eradication. However, we have found no evidence that eradicating H. pylori induces de novo GERD symptoms in ulcer patients.

Symptomatic benefit from eradicating Helicobacter pylori infection in patients with nonulcer dyspepsia

BACKGROUND

The eradication of Helicobacter pylori infection is beneficial in patients with gastric or duodenal ulcers. The value of eradicating the infection in patients with dyspepsia and no evidence of ulcer disease is not known.

METHODS

We performed a randomized, placebo-controlled trial comparing the efficacy of treatment for two weeks with 20 mg of omeprazole orally twice daily, 500 mg of amoxicillin three times daily (with 500 mg of tetracycline three times daily substituted for amoxicillin in patients allergic to penicillin), and 400 mg of metronidazole three times daily (160 patients) with that of omeprazole alone (158 patients) for resolving symptoms of dyspepsia in patients with H. pylori infection but no evidence of ulcer disease on upper gastrointestinal endoscopy. Symptoms were assessed with the Glasgow Dyspepsia Severity Score, with resolution of symptoms defined as a score of 0 or 1 in the preceding six months (maximal score, 20). One year later the patients were assessed to determine the frequency of the resolution of symptoms.

RESULTS

One month after the completion of treatment, 132 of 150 patients (88 percent) in the group assigned to received omeprazole and antibiotics had a negative test for H. pylori, as compared with 7 of 152 (5 percent) in the group assigned to receive omeprazole alone. One year later, dyspepsia had resolved in 33 of 154 patients (21 percent) in the group given omeprazole and antibiotics, as compared with 11 of 154 (7 percent) in the group given omeprazole alone (95 percent confidence interval for the difference, 7 to 22 percent; P<0.001). Among the patients in the group given omeprazole and antibiotics, the symptoms resolved in 26 of the 98 patients (27 percent) who had had symptoms for five years or less, as compared with 7 of the 56 patients (12 percent) who had had symptoms for more than five years (P=0.03).

CONCLUSIONS

In patients with H. pylori infection and nonulcer, or functional, dyspepsia, treatment with omeprazole and antibiotics to eradicate the infection is more likely to resolve symptoms than treatment with omeprazole alone.

Assessment of symptomatic response as predictor of Helicobacter pylori status following eradication therapy in patients with ulcer

BACKGROUND

Helicobacter pylori eradication therapy is routinely used for treating patients with peptic ulcer disease.

AIMS

To assess the value of symptomatic response to H pylori eradication therapy as a marker of post-treatment H pylori status.

PATIENTS AND METHODS

One hundred and nine dyspeptic patients with active duodenal or gastric ulceration association with H pylori infection had their symptoms measured by a validated questionnaire before and three months following H pylori eradication therapy. The symptomatic response was compared with post-treatment H pylori status as determined by the 14C urea breath test.

RESULTS

An eradication rate of 84% was achieved. Of the 92 patients eradicated of H pylori, 47% experienced complete or near complete resolution of dyspepsia. Of the 17 patients in whom the infection was not eradicated, only one (6%) experienced resolution of dyspepsia. Resolution of dyspepsia was therefore a powerful predictor of eradication of H pylori with a predictive value of 98%. In contrast, persistence of dyspepsia was a weak predictor of persisting infection with a predictive value of only 25%. Excluding patients with endoscopic evidence of coexisting oesophagitis and/or retrosternal discomfort or reflux at initial presentation did not increase the predictive value of persisting dyspepsia for persisting infection.

CONCLUSIONS

Complete resolution of dyspeptic symptoms is a powerful predictor of eradication of H pylori infection in ulcer patients. Persistence of symptoms is a weak predictor of persisting infection and patients with persisting dyspepsia must have their H pylori status rechecked to guide future management.

Caregivers' perceptions following gastrostomy in severely disabled children with feeding problems

Feeding difficulties are common in neurologically impaired children, often leading to great distress and frustration in the child and family. A gastrostomy may be advocated if oral intake is inadequate causing poor weight gain or when there is significant aspiration during feeding, or if feeding is very distressing. To find out if caregivers were happy with the outcome of gastrostomy (with fundoplication, when indicated), a 35-item questionnaire was developed and sent to 38 of them. Twenty-nine replies were received and appeared to be representative of the whole group. Coughing, choking, and vomiting improved in most cases. Weight gain improved in all in whom it had been a problem. In the majority, it became easier to give the children their medications although control of epilepsy was unchanged overall. Time spent feeding the child was reduced and many caregivers had more time to devote to other children and themselves. Only one parent regretted the operation. In children with severe disability and feeding problems, a gastrostomy (with fundoplication if there is significant reflux) can reduce symptoms of vomiting, coughing, and choking, help growth and improve quality of life in the child, when patients are properly selected.

The Helicobacter pylori breath test: a surrogate marker for peptic ulcer disease in dyspeptic patients

BACKGROUND

There is interest in noninvasive H pylori testing as a means of predicting diagnosis and determining management in dyspeptic patients.

AIMS

To assess the value of the 14C urea breath test as a predictor of peptic ulcer disease in patients presenting with dyspepsia.

PATIENTS AND METHODS

327 consecutive patients referred for investigation of dyspepsia had a 14C urea breath test performed before endoscopy. Patients were not included if they had previously confirmed ulcer disease, previous gastric surgery, or were taking non-steroidal anti-inflammatory drugs.

RESULTS

Of the 182 patients with a positive 14C urea breath test, duodenal and/or gastric ulcers were present in 45% and erosive duodenitis in a further 2%. Oesophagitis was present in 12% of the breath test positive patients with two thirds of the oesophagitis patients having co-existent ulcer disease. The prevalence of ulcer disease in the H pylori positive dyspeptic patients was independently related to smoking and previous investigation status. If previously uninvestigated, the prevalence of ulcers was 67% in smokers and 46% in non-smokers. If previous upper gastrointestinal investigations were negative, the prevalence of ulcers was 53% in smokers and 28% in non-smokers. Of the 136 patients with a negative breath test, only 5% had peptic ulcers. The most frequent endoscopic finding in these H pylori negative subjects was oesophagitis, being present in 17%.

CONCLUSIONS

This study demonstrates that a positive H pylori test is a powerful predictor of the presence of underlying ulcer disease in dyspeptic patients, especially if smokers, and that a negative H pylori test is a powerful predictor of the absence of ulcer disease. It also indicates that a negative upper gastrointestinal investigation does not preclude subsequent presentation with ulcer disease.

Clinical staff development: a two-way solution

This paper explains how a trust worked with a higher education institution to provide continuing education for clinical staff. The result was a staff development award that carries 60 CATS points at level 2. Evaluation shows that the award has not only helped staff in their practice but has also been cost-effective. In addition there have been benefits in terms of professional development for staff involved in running the programme.

The Whitaker hook in the treatment of posterior urethral valves

OBJECTIVE

To assess the efficacy of the Whitaker diathermy hook in the treatment of posterior urethral valves (PUV).

PATIENTS AND METHODS

Seventeen patients with PUV underwent primary treatment under general anaesthesia using a diathermy hook. The results were assessed by the clinical course of the patient, serial measurements of serum creatinine level and repeat cystography 6 weeks and 6 months after treatment.

RESULTS

There were no complications in 12 patients and they required no further treatment of the valves. Three patients required a repeat procedure which resolved the urethral obstruction. Two patients continued to show incomplete disruption of the valves and required endoscopic treatment. Two patients developed ureteric obstruction after disruption of the valves, which was treated by supravesical diversion and later reversed with no further treatment of the valves.

CONCLUSIONS

The Whitaker diathermy hook is a safe and effective instrument which has not gained its rightful place in the treatment of patients with PUV.

The umbilicus in gastroschisis: aesthetic considerations

Preservation of the umbilical cord attachment (UCA) in gastroschisis (GS) is still not routine practice. In a prospective series of 36 children with GS, it was always possible to preserve the UCA, even in those undergoing a temporary silo and delayed closure. Reconstruction by 'umbilical cord capping' left no additional scar and achieved a normal abdominal wall. Mild cellulitis in 3 infants resolved on antibiotics, and an initial umbilical weakness in 7 did not require additional surgery. We conclude that preservation of the UCA should be an integral part of surgical technique for all infants with GS. Reconstruction by 'umbilical cord capping' alone achieves an unscarred abdominal wall with an umbilicus of normal shape and position.

Production of IGF-I and IGF binding proteins by retinal cells in vitro

Insulin-like growth factor I (IGF-I) and its associated binding proteins (IGFBPs) have been identified in retinal tissues but their precise cellular origin remains unclear. The aim of this study was to examine the ability of three retinal cell types (microvascular endothelial cells, pericytes, and pigment epithelial cells) and a non-retinal cell type (Tenon's fibroblasts) to produce IGF-I and cell specific IGFBPs in vitro. Using a radioimmunoassay we demonstrated that all four cell types produce IGF-I and that this production continued over a 72 hour period. In addition, western ligand blotting revealed that each cell type produced at least one IGFBP and that each cell type produced a different IGFBP profile. Endothelial cells produced a 24 kDa band only, pericytes produced both a 24 kDa and a 34 kDa band, retinal pigment epithelial cells produced a 38-41 kDa band, while fibroblasts produced both a 24 kDa and a 30 kDa band. Laser scanning densitometry demonstrated that in the majority of experiments the IGFBPs accumulated in the culture medium over a 72 hour period. Neither IGF-I nor IGFBPs were observed in cell lysates indicating de novo synthesis and secretion in vitro. These results suggest an autocrine/paracrine function for IGF-I and its associated binding proteins which may play a significant role in both retinal physiology and disease.

Intradermal Hepatitis B Vaccine: Pilot study

Intramuscular administration of hepatitis B (HB) vaccine is safe and efficacious, but its cost has limited its availability. In this pilot study, 49 of 56 participants who received 2 μg of intradermal (ID) HB vaccine (one tenth the intramuscular dose) at the beginning of administration, at 1 month, and at 6 months developed protective levels of antibody to HB surface antigen. Although questions remain, the cost savings of this technique make it worth considering.

Ring chromosomes in a retroperitoneal lipoma of childhood

We report here the presence of ring chromosomes in a retroperitoneal lipoma from a 12-year-old male. Ring chromosomes are strongly associated with the pathological subtype "atypical lipoma" in adults. In contrast, however, the tumour described here possesses no atypical features.