Distinct spatiotemporal atrophy patterns in corticobasal syndrome are associated with different underlying pathologies

Objective

To identify imaging subtypes of the cortico-basal syndrome (CBS) based solely on a data-driven assessment of MRI atrophy patterns, and investigate whether these subtypes provide information on the underlying pathology.

Methods

We applied Subtype and Stage Inference (SuStaIn), a machine learning algorithm that identifies groups of individuals with distinct biomarker progression patterns, to a large cohort of 135 CBS cases (52 had a pathological or biomarker defined diagnosis) and 252 controls. The model was fit using volumetric features extracted from baseline T1-weighted MRI scans and validated using follow-up MRI. We compared the clinical phenotypes of each subtype and investigated whether there were differences in associated pathology between the subtypes.

Results

SuStaIn identified two subtypes with distinct sequences of atrophy progression; four-repeat-tauopathy confirmed cases were most commonly assigned to the Subcortical subtype (83% of CBS-PSP and 75% of CBS-CBD), while CBS-AD was most commonly assigned to the Fronto-parieto-occipital subtype (81% of CBS-AD). Subtype assignment was stable at follow-up (98% of cases), and individuals consistently progressed to higher stages (100% stayed at the same stage or progressed), supporting the model's ability to stage progression.

Interpretation

By jointly modelling disease stage and subtype, we provide data-driven evidence for at least two distinct and longitudinally stable spatiotemporal subtypes of atrophy in CBS that are associated with different underlying pathologies. In the absence of sensitive and specific biomarkers, accurately subtyping and staging individuals with CBS at baseline has important implications for screening on entry into clinical trials, as well as for tracking disease progression.

De novo priming: driver of immunotherapy responses or epiphenomenon?

The introduction of immunotherapy, in particular immune checkpoint inhibition, has revolutionised the treatment of a range of tumours; however, only a minority of patients respond to these therapies. Understanding the mechanisms by which different immune checkpoint inhibitors work will be critical for both predicting patients who will respond and to developing rational combination therapies to extend these benefits further. The initiation and maintenance of anti-tumour T cell responses is a complicated process split between both the tumour microenvironment and the tumour draining lymph node. As understanding of this process has increased, it has become apparent that immune checkpoint inhibitors can act both within the tumour and in the draining lymph node and that they can target both already activated T cells as well as stimulating the priming of novel T cell clones. Currently, it seems likely that immune checkpoint inhibition acts both within the tumour and in the tumour draining lymph node both reinvigorating existing clones and driving further de novo priming of novel clones. The relative contributions of these sites and targets may depend on the type of model being used and the timeline of the response. Shorter models emphasise the effect of reinvigoration in the absence of recruitment of new clones but studies spanning longer time periods examining T cell clones in patients demonstrate clonal replacement. Ultimately, further work is needed to determine which of the diverse effects of immune checkpoint inhibitors are the fundamental drivers of anti-tumour responses in patients.

Comparison of United Kingdom and United States screening criteria for detecting retinopathy of prematurity in Hong Kong

INTRODUCTION

We examined whether the United Kingdom (UK) or the United States (US) screening criteria are more appropriate for retinopathy of prematurity (ROP) screening in Hong Kong, in terms of sensitivity for detecting type 1 ROP and the number of infants requiring screening.

METHODS

In this retrospective cohort study, we reviewed the medical records of all infants who underwent ROP screening from 2009 to 2018 at a tertiary hospital in Hong Kong. During this period, all infants born at gestational age (GA) ≤31 weeks and 6 days or birth weight (BW) <1501 g (ie, the UK screening criteria) underwent ROP screening. We determined the number of infants requiring screening and the number of type 1 ROP cases that would have been missed if the US screening criteria (GA ≤30 weeks & 0 days or BW ≤1500 g) had been used.

RESULTS

Overall, 796 infants were screened using the UK screening criteria. If the US screening criteria had been used, the number of infants requiring screening would have decreased by 21.1%; all type 1 ROP cases would have been detected (38/38, 100% sensitivity). Of the 168 infants who would not have been screened using the US screening criteria, only four of them (2.4%) had developed ROP (all maximum stage 1 only).

CONCLUSION

In our population, the use of the US screening criteria could reduce the number of infants screened without compromising sensitivity for the detection of type 1 ROP requiring treatment. We suggest narrowing the GA criterion for consistency with the US screening criteria during ROP screening in Hong Kong.

Mutual information: Measuring nonlinear dependence in longitudinal epidemiological data

Given a large clinical database of longitudinal patient information including many covariates, it is computationally prohibitive to consider all types of interdependence between patient variables of interest. This challenge motivates the use of mutual information (MI), a statistical summary of data interdependence with appealing properties that make it a suitable alternative or addition to correlation for identifying relationships in data. MI: (i) captures all types of dependence, both linear and nonlinear, (ii) is zero only when random variables are independent, (iii) serves as a measure of relationship strength (similar to but more general than R2), and (iv) is interpreted the same way for numerical and categorical data. Unfortunately, MI typically receives little to no attention in introductory statistics courses and is more difficult than correlation to estimate from data. In this article, we motivate the use of MI in the analyses of epidemiologic data, while providing a general introduction to estimation and interpretation. We illustrate its utility through a retrospective study relating intraoperative heart rate (HR) and mean arterial pressure (MAP). We: (i) show postoperative mortality is associated with decreased MI between HR and MAP and (ii) improve existing postoperative mortality risk assessment by including MI and additional hemodynamic statistics.

Limits of epidemic prediction using SIR models

The Susceptible-Infectious-Recovered (SIR) equations and their extensions comprise a commonly utilized set of models for understanding and predicting the course of an epidemic. In practice, it is of substantial interest to estimate the model parameters based on noisy observations early in the outbreak, well before the epidemic reaches its peak. This allows prediction of the subsequent course of the epidemic and design of appropriate interventions. However, accurately inferring SIR model parameters in such scenarios is problematic. This article provides novel, theoretical insight on this issue of practical identifiability of the SIR model. Our theory provides new understanding of the inferential limits of routinely used epidemic models and provides a valuable addition to current simulate-and-check methods. We illustrate some practical implications through application to a real-world epidemic data set.

Toward Predicting Human Performance Outcomes From Wearable Technologies: A Computational Modeling Approach

Wearable technologies for measuring digital and chemical physiology are pervading the consumer market and hold potential to reliably classify states of relevance to human performance including stress, sleep deprivation, and physical exertion. The ability to efficiently and accurately classify physiological states based on wearable devices is improving. However, the inherent variability of human behavior within and across individuals makes it challenging to predict how identified states influence human performance outcomes of relevance to military operations and other high-stakes domains. We describe a computational modeling approach to address this challenge, seeking to translate user states obtained from a variety of sources including wearable devices into relevant and actionable insights across the cognitive and physical domains. Three status predictors were considered: stress level, sleep status, and extent of physical exertion; these independent variables were used to predict three human performance outcomes: reaction time, executive function, and perceptuo-motor control. The approach provides a complete, conditional probabilistic model of the performance variables given the status predictors. Construction of the model leverages diverse raw data sources to estimate marginal probability density functions for each of six independent and dependent variables of interest using parametric modeling and maximum likelihood estimation. The joint distributions among variables were optimized using an adaptive LASSO approach based on the strength and directionality of conditional relationships (effect sizes) derived from meta-analyses of extant research. The model optimization process converged on solutions that maintain the integrity of the original marginal distributions and the directionality and robustness of conditional relationships. The modeling framework described provides a flexible and extensible solution for human performance prediction, affording efficient expansion with additional independent and dependent variables of interest, ingestion of new raw data, and extension to two- and three-way interactions among independent variables. Continuing work includes model expansion to multiple independent and dependent variables, real-time model stimulation by wearable devices, individualized and small-group prediction, and laboratory and field validation.

O45 Gender representation in the authorship of surgical journals

Introduction

Despite the increase in female doctors graduating from medical schools internationally, gender disparity in surgery remains. This disparity is also evident in academic surgery. This study aims to quantify the extent of gender disparity in the authorship of articles in major surgical journals.

Method

The Top 10 Surgical Journals were identified using SCImago Journal Rank indicator. Authorship details for papers published in 2019 were collected. Authors were assigned as female, male or unknown using Gender API software (Gender API, Germany). For each journal, the percentage of first author, last author, corresponding author and all authors split by gender was interrogated. Gender differences by publication type were also identified.

Result

9 of the 10 journals had full names publicly available. Overall, 2414 manuscripts were interrogated which included 16,277 number of authors. Respectively, females and males accounted for 29.8% [22.9–34.9%] (N = 655) and 62.4% [56.3–70.2%] (N = 1419) of first authors, 20.6% [11.8–27.1%] (N = 453) and 74.2% [65.6–84.1%] (N = 1706) of last authors, 23.9% [14.9–29.6%] (N = 510) and 69.9% [60.5–79.3%] (N = 2341) of corresponding authors and in total 27% [19.4–31.6%] (N = 4298) and 65.5% [58.6–73.4%] (N = 9982) of all authors. The wide range in these results could be a result of various factors.

Conclusion

This study has identified a gender imbalance in authorship positions, with the greatest difference observed in the most senior author position. Whether this is reflective of the current disparity observed in senior academic surgery positions or due to gender discrimination is unclear.

Take-home Message

This study identified a gender imbalance in authorship positions of major surgical journals, which has implications for women who choose to pursue a career in academic surgery.

O54: GENDER REPRESENTATION IN EDITORIAL BOARDS OF INTERNATIONAL GENERAL SURGERY JOURNALS

Introduction

Despite women constituting over half of new UK doctors, and a similar proportion worldwide, gender disparity remains an issue throughout academic medicine. Surgery has shown particularly slow progress towards gender parity. This study aims to quantify gender representation within editorial boards of the top 25 general surgical journals.

Method

All surgical journals were collated using the SCImago Journal Rank (SJR) and Journal Impact Factor (JIF). Non general surgery journals were excluded. Journals were contacted requesting gender editorial team demographics. Editorial board data was collected via journal websites on 20th November 2019.

Result

The top 25 surgical journals were determined through SJR and JIF ranking methods. Editorial board data was publicly available for 31 of these 32 different surgical journals. This data was then examined. Women accounted for 18.4% (576/3135) of total editorial board positions. Women constituted 12.5% (5/40) of Editors-in-Chief positions, 31.6% (31/98) of Deputy Editors and 17.2% (416/2415) of general editorial board positions.

Conclusion

For the first time, gender disparity has been demonstrated within editorial boards of the most prominent general surgery journals. The implications of such significant gender disparity are wide reaching. Action should be taken to champion fair female representation, eliminate risk of bias and provide more visible female role models in academic surgery.

Take-home message

For the first time, this study demonstrates gender disparity in Editorial boards of major general surgery journals. Action should be taken to champion fair female representation, eliminate risk of bias and provide more visible female role models in academic surgery.

Gender representation in editorial boards of international general surgery journals

Background

Despite women constituting over half of new doctors, gender disparity remains an issue. Surgery has shown particularly slow progress towards gender parity. This study aimed to quantify gender representation within editorial boards of the highest ranking international general surgery journals.

Methods

Surgical journals were collated using two indices: SCImago Journal Rank (SJR) and Journal Impact Factor (JIF). Non-general surgery journals were excluded. Journals were contacted, requesting gender editorial team demographics. Editorial board data were collected via journal websites on 28 November 2019.

Results

The top 25 general surgery journals according to SJR and JIF ranking methods were determined, identifying 28 unique journals. Editorial board data were publicly available for 27 of these 28 surgical journals, and were examined. Women accounted for 20.2 per cent (568 of 2816) of total editorial board positions. Women constituted 11 per cent (4 of 36) of editor-in-chief positions, 32 per cent (29 of 92) of deputy editors, and 19.1 per cent (369 of 1935) of general editorial board positions.

Conclusion

The findings demonstrate gender disparity within editorial boards of the most prominent general surgery journals.

Epidemiology of myopia and prevention of myopia progression in children in East Asia: a review

INTRODUCTION

Myopia (short-sightedness) exhibits high prevalence in East Asia. Methods to mitigate myopia progression are important in preventing the vision-threatening complications associated with high myopia. In this review, we examine the regional epidemiology of myopia and provide updated evidence regarding interventions to slow myopia progression in children.

METHODS

We performed a literature search using PubMed from the date of inception through 25 June 2018. Studies involving myopia epidemiology and control of myopia progression were selected; only studies published in English were reviewed. Preference was given to prospective studies, as well as those conducted in Hong Kong or East Asia.

RESULTS

Atropine eye drops and pirenzepine eye gel are highly effective for controlling myopia progression in children. Orthokeratology, peripheral defocus contact lenses, bifocal or progressive addition spectacles, and increased involvement in outdoor activities are also effective for controlling myopia progression; however, myopia undercorrection and single vision contact lenses are ineffective.

CONCLUSION

Although various methods are effective for controlling myopia progression in children, no curative remedy exists for myopia. Health care professionals should be aware of the available methods, as well as their risks and benefits. Treatment should be individualised and based on the preferences of the patient's family, after full discussion of the risks and benefits of each modality.

Expectations of outcomes in patients with colorectal cancer

Background

Understanding patients' expectations of their treatment is critical to ensure appropriate treatment decisions, and to explore how expectations influence coping, quality of life and well‐being. This study aimed to examine these issues related to treatment in patients with colorectal cancer.

Methods

A literature search from January 1946 to September 2016 was performed to identify available data regarding patients' expectations of outcomes following colorectal cancer treatment. A narrative synthesis of the evidence was planned.

Results

Of 4337 items initially identified, 20 articles were included in the review. In studies presenting data on overall and short‐term survival, patients considerably overestimated prognosis. Patients also had unrealistic expectations of the negative aspects of chemotherapy and stomas. There was marked discordance between patients' and clinicians' expectations regarding chemotherapy, end‐of‐life care, bowel function and psychosocial outcomes. Level of education was the most consistent factor influencing the accuracy of patients' expectations.

Conclusion

Patients with colorectal cancer frequently have unrealistic expectations of treatment. Marked disparities exist between patients' and clinicians' expectations of outcomes.

Impact of a National Controlled Donation After Circulatory Death (DCD) Program on Organ Donation in the United Kingdom: A 10-Year Study

Organ transplantation is the most successful treatment for some forms of organ failure, yet a lack of organs means many die on the waiting list. In the United Kingdom, the Organ Donation Taskforce was set up to identify barriers to organ donation and in 2008 released its first report (Organ Donation Taskforce Report; ODTR). This study assesses the success since the ODTR and examines the impact of the United Kingdom's controlled donation after circulatory death (DCD) program and the controversies surrounding it. There were 12 864 intended donation after brain death (DBD) or DCD donors from April 2004 to March 2014. When the 5 years preceding the ODTR was compared to the 5 years following, intended DCD donors increased 292% (1187 to 4652), and intended DBD donors increased 11% (3327 to 3698). Organs retrieved per intended DBD donor remained static (3.30 to 3.26), whereas there was a decrease in DCD (1.54 to 0.99) due to a large rise in donors who did not proceed to donation (325 to 2464). The majority of DCD donors who proceeded did so within 30 min from time of withdrawal. Our study suggests further work on converting eligible referrals to organ donation and exploring methods of converting DCD to DBD donors.

Grandparents of children with cancer: Quality of life, medication and hospitalizations

BACKGROUND

Grandparents can play a crucial role of providing emotional and practical support for families facing childhood cancer. Yet, many have their own healthcare needs. This controlled study systematically assesses the impact of childhood cancer on grandparents' quality of life (QOL). Our objective was to compare QOL in grandparents of children with and without cancer and to identify factors associated with grandparents' QOL.

PROCEDURE

Grandparents (N = 222) completed two patient-reported outcome (PRO) measures assessing QOL: EQ-5D-5L and WHOQOL-BREF. Secondary endpoints included sleep, medications and hospitalizations. We used independent samples t-tests and multivariate linear regression to assess between-group differences and identify predictors.

RESULTS

Grandparents of children with cancer (n = 89) reported significantly worse QOL than controls (n = 133) [mean WHOQOL-BREF score: 75.6 (SD = 17.6) vs. 81.5 (15.6), P = 0.007; mean EQ-5D-5L index value: 0.777 (0.20) vs. 0.874 (0.14), P < 0.001)]. They also reported more problems with anxiety and depression (47.2 vs. 21.8%, P < 0.001) and pain (64.8 vs. 49.6%, P = 0.031). Grandparents of children with cancer reported taking longer to fall asleep [mean: 30.4 min (55.6) vs. 18.2 (20.2), P = 0.011] and taking more medications in the last 4 weeks [mean: 2.9 (SD = 3.8) vs. 1.8 (SD = 2.3), P = 0.012]. Hospitalizations were comparable across groups. Grandmothers, those living in urban locations, and retired/unemployed grandparents experienced reduced QOL.

CONCLUSIONS

Grandparents are significantly affected by childhood cancer. The impact appears across many domains of life and results in meaningful QOL differences. Given that four or more individuals may be affected per child, and that grandparent well-being can influence the whole family, interventions targeting at-risk grandparents are needed.

The management of the surgical complications of HELLP syndrome

INTRODUCTION

Complications from HELLP (Haemolysis, Elevated Liver enzymes and Low Platelet) syndrome may present as an emergency to any surgeon. We review the ten-year experience of a tertiary hepatobiliary centre managing HELLP patients. Three selected cases are described to highlight our management strategy and a systematic review of the recent literature is presented.

METHODS

All patients with HELLP syndrome were identified from a prospectively maintained database and their details collated. Subsequently, a detailed search of PubMed was carried out to identify all case series of HELLP syndrome in the literature in the English language since 1999.

RESULTS

On review of 1,002 cases, 10 patients were identified with surgical complications of HELLP syndrome. Seven of these patients had a significant liver injury. Only three of these required surgical intervention for liver injury although four other patients required surgical intervention for other complications. There was no maternal mortality in this series. Review of the literature identified 49 cases in 31 publications. The management approaches of these patients were compared with ours.

CONCLUSIONS

We have presented a large series of patients with surgical complications resulting from HELLP syndrome managed without maternal mortality. This review has confirmed that haemodynamically stable patients with HELLP syndrome associated hepatic rupture can be conservatively treated successfully. However, in unstable patients, perihepatic packing and transfer to a specialist liver unit is recommended.

Variation in referral practice for patients with colorectal cancer liver metastases

BACKGROUND

Half of patients with colorectal cancer develop liver metastases. There remains great variability between hospitals in rates of liver resection for colorectal cancer liver metastases (CLM). This study aimed to determine how many patients with potentially resectable CLM are not seen by specialist liver surgeons.

METHODS

Patients presenting with new CLM in a cancer network consisting of a tertiary centre and seven attached hospitals were studied prospectively over 12 months. Data were collected retrospectively for patients who did not have a complete data set. Outcomes for patients referred to the liver tertiary centre were collated. The radiology of tumours deemed inoperable by the local colorectal specialist teams was reviewed by specialist liver surgeons and radiologists.

RESULTS

In total, 631 patients with CLM were assessed. Prospective data were complete for 241 patients, and 64 (26.6 per cent) of these were referred to the specialist liver team for consideration of resection. No decision was documented for 16 patients (6.6 per cent). Of those not referred, 30 (18.6 per cent) were deemed unfit or refused and 131 (81.4 per cent) were thought inoperable. Referral rates varied between hospitals (13-43.6 per cent). Of 131 patients deemed fit but inoperable by the colorectal specialist teams, 38 (29.0 per cent) were deemed operable and 20 (15.3 per cent) had equivocal imaging when assessed retrospectively by liver specialists. In total, 142 of the 631 patients were referred to liver specialists for consideration of treatments, and 107 (75.4 per cent) treated with curative intent.

CONCLUSION

A considerable number of patients with potentially resectable CLM are not assessed by specialist liver teams. Improved referral rates could greatly improve resection rates for CLM, which may improve outcomes for patients with colorectal cancer.

Accessory gallbladder: a new anatomical variation arising from both left and right hepatic ducts

We present a case of accessory gallbladder demonstrating an anatomical variation not previously reported. While rare, accessory gallbladders are an important consideration if a cholecystectomy is to be performed. We also present a brief literature review of accessory gallbladders.

Repeat hepatic resection for colorectal liver metastases

BACKGROUND

Some 75-80 per cent of patients undergoing liver resection for colorectal liver metastases develop intrahepatic recurrence. A significant number of these can be considered for repeat liver surgery. This study examined the outcomes of repeat liver resection for the treatment of recurrent colorectal metastases confined to the liver.

METHODS

Patients who underwent repeat liver resection in a single tertiary referral hepatobiliary centre were identified from a database. Clinicopathological variables were analysed to assess factors predictive of survival.

RESULTS

A total of 195 patients underwent repeat resection between 1993 and 2010. Median age was 63 years, and the median interval between first and repeat resection was 13·8 months. Thirty-three patients (16·9 per cent) underwent completion hemihepatectomy or extended hemihepatectomy and the remainder had non-anatomical or segmental resection. The 30-day mortality rate was 1·5 per cent, and the overall 30-day morbidity rate was 20·0 per cent. Overall 1-, 3- and 5-year survival rates were 91·2, 44·3 and 29·4 per cent respectively. Tumour size 5 cm or greater was the only independent predictor of overall survival (relative risk 1·71, 95 per cent confidence interval 1·08 to 2·70; P = 0·021). Neoadjuvant chemotherapy before resection, perioperative blood transfusion, bilobar disease, R1 resection margin and multiple metastases were among factors that did not significantly influence survival.

CONCLUSION

Repeat hepatic resection remains the only curative option for patients presenting with recurrent colorectal liver metastases.

A KrasG12D-driven genetic mouse model of pancreatic cancer requires glypican-1 for efficient proliferation and angiogenesis

Pancreatic ductal adenocarcinomas (PDACs) exhibit multiple molecular alterations and overexpress heparin-binding growth factors (HBGFs) and glypican-1 (GPC1), a heparan sulfate proteoglycan that promotes efficient signaling by HBGFs. It is not known, however, whether GPC1 has a role in genetic mouse models of PDAC. Therefore, we generated a GPC1 null mouse that combines pancreas-specific Cre-mediated activation of oncogenic Kras (Kras(G12D)) with deletion of a conditional INK4A/Arf allele (Pdx1-Cre;LSL-Kras(G12D);INK4A/Arf(lox/lox);GPC1(-/-) mice). By comparison with Pdx1-Cre;LSL-Kras(G12D);INK4A/Arf(lox/lox) mice that were wild type for GPC1, the Pdx1-Cre;LSL-Kras(G12D);INK4A/Arf(lox/lox);GPC1(-/-) mice exhibited attenuated pancreatic tumor growth and invasiveness, decreased cancer cell proliferation and mitogen-activated protein kinase activation. These mice also exhibited suppressed angiogenesis in conjunction with decreased expression of messenger RNAs encoding several pro-angiogenic factors and molecules, including vascular endothelial growth factor-A (VEGF-A), SRY-box containing gene (SOX17), chemokine C-X3-C motif ligand 1 (CX3CL1) and integrin β3 (ITGB3). Moreover, pancreatic cancer cells isolated from the tumors of GPC1(-/-) mice were not as invasive in response to fibroblast growth factor-2 (FGF-2) as cancer cells isolated from wild-type mice, and formed smaller tumors that exhibited an attenuated metastatic potential. Similarly, VEGF-A and FGF-2 did not enhance the migration of hepatic endothelial cells and immortalized murine embryonic fibroblasts isolated from GPC1 null mice. These data demonstrate in an oncogenic Kras-driven genetic mouse model of PDAC that tumor growth, angiogenesis and invasion are enhanced by GPC1, and suggest that suppression of GPC1 may be an important component of therapeutic strategies in PDAC.

Parastomal hernia causing gastric emphysema

We report a case of a parastomal hernia in which the stomach became incarcerated. This is an unusual yet serious complication of parastomal hernias.

Biliary papillomatosis in three Caucasian patients in a Western centre

INTRODUCTION

Biliary papillomatosis (BP) is a rare condition with a strong potential for malignant transformation and cases from Western centres are sparse.(1) We discuss the presentation, investigation and management of this condition in three Caucasian patients and present a review of the existing literature on BP.

PATIENTS AND METHODS

The case notes of three Caucasian patients with BP who presented to our tertiary referral centre were reviewed. Their case histories, investigations and managements are presented. A search of MEDLINE, PubMed and Cochrane databases was performed to review relevant literature around BP.

DISCUSSION

BP is a rare condition characterised by multiple papillary adenomas involving the biliary tree which lead to recurrent attacks of cholangitis. It is a low-grade neoplasm with high malignant potential and should be regarded as a pre-malignant lesion.

Randomized clinical trial of routine on-table cholangiography during laparoscopic cholecystectomy (Br J Surg 2011; 98: 362–367)

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.

CYLD mutations underlie Brooke-Spiegler, familial cylindromatosis, and multiple familial trichoepithelioma syndromes

Brooke-Spiegler syndrome (BSS), familial cylindromatosis (FC), and multiple familial trichoepithelioma (MFT), originally described as distinct inherited disorders, are characterized by a variety of skin appendage neoplasms. Mutations in the CYLD gene are found in individuals with these syndromes. We describe a single family with affected members exhibiting either the FC or the MFT phenotypes associated with a mutation in the CYLD gene. These findings support the notion that BSS, FC, and MFT represent phenotypic variation of a single defect. Of interest, one of the affected individuals described in this report exhibits a severe phenotype illustrating the morbidity of the disorder.

Assessing automobile head restraint positioning in Portland, Oregon

OBJECTIVE

Automobile head restraints, when used properly, have been shown to decrease the incidence and severity of whiplash injuries to the neck. Before the development of a public campaign on proper head restraint positioning, the authors assessed head restraint positioning and public understanding.

DESIGN

Over a one month period, the position of the vehicle head restraint of drivers was observed in moving cars in the city of Portland, Oregon (population 530,000). Optimal position was defined as having the head restraint above the ears with the back of the head touching the head restraint. A questionnaire on head restraint understanding was administered to people during jury service.

RESULTS

Of the 4287 drivers observed, 1% (n = 30) had no head restraint on their seat, 4% (n = 158) had a fixed head restraint, and 95% (n = 4099) had an adjustable head restraint. Among the fixed head restraints, 21% (33/158) were positioned optimally with no horizontal gap. Among the adjustable head restraints, only 7% (280/4099) had optimal head restraint positioning. Overall, 93% (3974/4287) of all head restraints observed were suboptimally positioned. Seventy five percent (38/51) of polled Portland residents identified safety as the primary head restraint function.

CONCLUSION

Ninety three percent of all head restraints observed were suboptimally positioned. Fixed head restraints were three times more likely to be in optimal position than adjustable head restraints (21% v 7%). Most polled Portland residents understood the proper function and positioning of head restraints. This discrepancy between actual practice and understanding should be addressed with public education and manufacturer design changes.

Genotype-phenotype correlation and frequency of the 3199del6 cystic fibrosis mutation among I148T carriers: results from a collaborative study

PURPOSE

We expect that the mutation panel currently recommended for preconception/prenatal CF carrier screening will be modified as new information is learned regarding the phenotype associated with specific mutations and allele frequencies in various populations. One such example is the I148T mutation, originally described as a severe CF mutation. After implementation of CF population-based carrier screening, we learned that I148T exists as a complex allele with 3199del6 in patients with clinical CF, whereas asymptomatic compound heterozygotes for I148T and a second severe CF mutation were negative for 3199del6.

METHODS

We performed reflex testing for 3199del6 on 663 unrelated specimens, including I148T heterozygotes, compound heterozygotes, and a homozygous individual.

RESULTS

Less than 1% of I148T carriers were also positive for 3199del6. Excluding subjects tested because of a suspected or known CF diagnosis or positive family history, 0.6% of I148T-positive individuals were also positive for 3199del6. We identified 1 I148T homozygote and 6 unrelated compound heterozygous individuals with I148T and a second CF variant (2 of whom also carried 3199del6). In addition, one fetus with echogenic bowel and one infertile male were heterozygous for I148T (3199del6 negative).

CONCLUSIONS

Reflex testing for 3199del6 should be considered whenever I148T is identified. Reflex testing is of particular importance for any symptomatic patient or whenever one member of a couple carries a deleterious CF mutation and the other member is an I148T heterozygote. Further population data are required to determine if I148T, in the absence of 3199del6, is associated with mild or atypical CF or male infertility.

A randomised trial comparing 0.02% mitomycin C and limbal conjunctival autograft after excision of primary pterygium

BACKGROUND

Mitomycin C (MMC) and limbal conjunctival autograft (LCAU) are two known useful adjuvants in the prevention of pterygial recurrence. This study was conducted to compare the outcome of these two treatments.

METHODS

Prospective study on consecutive cases of primary pterygium (February 2001 to March 2002) randomised into two adjuvant groups: (1) intraoperative 0.02% MMC for 5 minutes or (2) LCAU. Patients were followed for recurrence (defined as fibrovascular tissue invading the cornea >1.5mm) and complications for a period of one year.

RESULTS

115 eyes in 114 patients who completed the study were randomised to receive MMC (n = 63) and LCAU (n = 52). There were 10 recurrences (15.9%) in the MMC group and only one recurrence (1.9%) in the LCAU group. There was a statistically significant difference in the recurrence rate between the two groups (p = 0.04). There were a total of three conjunctival cysts, three symblephara, one granuloma, and one dellen. No other visually significant complications were encountered in either group.

CONCLUSION

Although LCAU resulted in better one year success rates, it is technically more difficult and inapplicable in cases with previous limbal disturbance. Simple excision followed by MMC or LCAU are both safe and acceptable adjuvants for pterygium excision. Choice of adjuvant should be carefully made based on assessment of recurrence risk, local practices, and surgeon's expertise.

The use of autologous serum tears in persistent corneal epithelial defects

PURPOSE

Persistent corneal epithelial defects (PED) present a very challenging problem to anterior segment surgeons. Autologous serum tears had been demonstrated to be beneficial in the treatment of PED. The current study was conducted to review the local spectrum of indications and to examine the outcome of autologous serum tear usage.

METHODS

All cases of PED treated with autologous serum tears at a tertiary referral centre for the period August 1999 - July 2001 were identified and reviewed.

RESULTS

A total of 10 eyes from 10 patients were identified (5OD : 5OS). The gender ratio was 7M : 3F and the mean age was 36.8 (range 17-73) years old. The mean duration of PED before the usage of autologous serum tears was 22.4+/-69.6 days. Six eyes healed within 2 weeks, but two eyes failed to heal after 1 month of treatment and two patients defaulted follow-up. No adverse effects were observed with the addition of autoserum tears.

CONCLUSIONS

The results of the current study correlated well with previous reported studies. Autologous serum tears may be considered as a valuable adjunct in the management of recalcitrant cases of PED.

A modified technique of scleral fixated intraocular lenses for aphakic correction

PURPOSE

To examine the safety and efficacy of a modified scleral fixated intraocular lens (SFIOL) technique combining a scleral tunnel for intraocular lens (IOL) insertion, horizontal passage of sutures, and performing anterior vitrectomy through self-sealing pars plana sclerostomies.

METHODS

Retrospective review of all patients who underwent SFIOL for aphakic correction at the Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong (a tertiary referral centre) between October 2000 and December 2001 with either the modified or conventional techniques.

RESULTS

A total of 20 eyes were identified. Eight modified (Group 1) and 12 conventional (Group 2) with a mean follow-up of 18.3 months. Postoperatively, all the eyes improved on unaided preoperative acuity and they all had a stable and well-positioned IOL. In all, 85% (7/8) of eyes in Group 1 maintained or improved best-corrected visual acuity.

CONCLUSIONS

The modified SFIOL technique was found to be as safe and effective as conventional techniques. The main advantages of this technique include easy intraoperative suture management and superior globe maintenance.

The prevalence of pseudoexfoliation syndrome in Chinese people

BACKGROUND

Pseudoexfoliation syndrome (PXS) is regarded as rare in people of Chinese ethnicity but the prevalence of this condition is not known. This epidemiology study was conducted to assess the prevalence of PXS in cataract patients and to report the clinical features present.

METHODS

Prospective descriptive study conducted in the period from March 1999 to May 2001 in ophthalmology departments in cluster hospitals serving a population of about 1.2 million. 500 consecutive patients aged 60 or above attending the general ophthalmic clinics with a presumed diagnosis of cataract were recruited. A detailed examination including biomicroscopy, intraocular measurement, and gonioscopy were performed on all patients. All positive PXS cases were documented photographically.

RESULTS

500 patients were examined. They ranged from the ages of 60 to 91 years old, with a male to female ratio of 1:2. 40% suffered from hypertension while 24% were known diabetics. Only two positive cases (0.4%) of PXS were identified in the study population. 18% of all eyes were found to have narrow angles (defined as grade 0 to 2 by Shaffer grading). Nuclear sclerosis was the single most common type of lens opacity.

CONCLUSION

PXS is a rare condition in Chinese people. A prevalence rate of 0.4% in patients aged 60 or above was identified in this hospital based epidemiology study. To the best of our knowledge, this was the first study conducted in a Chinese population to examine the prevalence of PXS.

Combined intravenous pulse methylprednisolone and oral cyclosporine A in the treatment of corneal graft rejection: 5-year experience

PURPOSE

To report the mid-term results of a treatment strategy using topical steroids, intravenous pulse methyl prednisolone and oral cyclosporine A (CSA) for the treatment of acute corneal graft rejection.

METHODS

Noncomparative, interventional case series. Treatment of corneal graft rejection included 1% prednisolone eye drops, intravenous infusion of 500 mg methyl prednisolone, and oral CSA in two regimens--standard dose was 15 mg/kg/day for 2 days, 7.5 mg/kg/day for 2 days, then adjusted to maintain trough blood levels of 100-200 microg/l; low dose was 2 mg/kg/day with no loading dose.

RESULTS

Outcome in 34 eyes of 34 patients (21 M;13 F) aged 60 +/- 17.7 years (range 9-83 years), who presented after an average duration of 6.6 +/- 6.3 days (range 0-30 days) following acute corneal graft rejection, are reported. Twenty-five patients received standard dose CSA while nine patients received the low dose regimen. Mean duration of treatment before reversal of graft rejection was 13.6 +/- 12.1 days (range 3-54 days). Treatment was successful in reversing the graft rejection in 32/34 (94%) eyes. Irreversible graft failure occurred in one eye in each group. During a mean follow-up period of 19.2 +/- 16.7 months (range 1-55 months), further episodes of graft rejection were seen in 1/32 (3%) eyes. Complications due to treatment included: duodenal ulcer in one patient that responded to medical treatment, and transient elevation in serum creatinine levels in three patients, which returned to normal after decrease in dosage or cessation of oral CSA.

CONCLUSION

Our 5-year experience with the use of oral CSA in the treatment of acute corneal graft rejection has shown this treatment approach to be safe and effective in reversing the rejection process. This approach may also protect the graft from subsequent episodes of allograft rejection. A randomised controlled trial to further delineate the role of CSA in reversing acute graft rejection seems warranted.

Structural integrity of histone H2B in vivo requires the activity of protein L-isoaspartate O-methyltransferase, a putative protein repair enzyme

Protein L-isoaspartate O-methyltransferase (PIMT) is postulated to repair beta-aspartyl linkages (isoaspartyl (isoAsp)) that accumulate at certain Asp-Xaa and Asn-Xaa sites in association with protein aging and deamidation. To identify major targets of PIMT action we cultured rat PC12 cells with adenosine dialdehyde (AdOx), a methyltransferase inhibitor that promotes accumulation of isoAsp in vivo. Subcellular fractionation of AdOx-treated cells revealed marked accumulation of isoAsp in a 14-kDa nuclear protein. Gel electrophoresis and chromatography of nuclei (3)H-methylated in vitro by PIMT revealed this protein to be histone H2B. The isoAsp content of H2B in AdOx-treated cells was approximately 18 times that in control cells, although no isoAsp was seen in other core histones, regardless of treatment. To confirm the relevance and specificity of this effect, we measured isoAsp levels in histones from brains of PIMT knockout mice. IsoAsp was found at near stoichiometric levels in H2B extracted from knockout brains and was at least 80 times greater than that in H2B from normal mice. Little or no isoAsp was detected in H2A, H3, or H4 from mice of either genotype. Accumulation of isoAsp in histone H2B may disrupt normal gene regulation and contribute to the reduced life span that characterizes PIMT knockouts. In addition to disrupting protein function, isoAsp has been shown to trigger immunity against self-proteins. The propensity of H2B to generate isoAsp in vivo may help explain why this histone in particular is found as a major antigen in autoimmune diseases such as lupus erythematosus.

Efficacy of lignocaine gel for outpatient laser treatment in inflamed eyes

PURPOSE

To evaluate the efficacy and safety of topical 2% lignocaine gel in providing analgesia during outpatient transpupillary or trans-scleral laser treatment of inflamed eyes.

METHODS

A prospective study was carried out of consecutive eligible eyes undergoing laser treatment using 2% lignocaine gel as a topical anaesthetic and a coupling medium. At the conclusion of each procedure, patients were asked to grade a pain score (0 = no discomfort, 1 = mild discomfort, 2 = mild pain, 3 = moderate pain, 4 = severe pain).

RESULTS

Twenty eyes in 19 patients received laser treatment. No pain was reported in 95% of cases treated (no discomfort in 75%, mild discomfort in 20%) and only mild pain in 5% (one patient). No adverse reactions were encountered in any of the patients. There were no complications associated with the procedures.

CONCLUSIONS

Lignocaine 2% gel is safe and effective for outpatient transpupillary and trans-scleral laser treatment in inflamed eyes, providing adequate analgesia and serving as a coupling medium at the same time.

Mitral valve regurgitation causing right upper lobe pulmonary edema

When radiography is performed in patients with mitral regurgitation, cardiogenic pulmonary edema is a typical finding; however, asymmetric pulmonary edema has also been reported. We describe the case of a patient in whom mitral valve regurgitation caused isolated pulmonary edema in the right upper lung. We include a discussion of pulmonary edema in conjunction with mitral regurgitation.

Ocular hypertensive response to topical dexamethasone in children: a dose-dependent phenomenon

OBJECTIVE

To investigate the ocular-hypertensive response to different dosages of topical dexamethasone eye drops in Chinese children.

DESIGN

Prospective, randomized clinical trial.

PARTICIPANTS

Thirty-one consecutive children undergoing bilateral strabismus surgery.

INTERVENTION

Topical dexamethasone (0.1%) was administered to children undergoing bilateral strabismus surgery. They were all less than 10 years of age. One eye was randomized to receive a regimen of four times daily, and another received a twice daily regimen. Intraocular pressure (IOP) was serially measured in the postoperative period for 4 weeks or more. Topical steroids were discontinued if IOP was 30 mmHg or more.

MAIN OUTCOME MEASURES

Intraocular pressure was measured on the day before the surgery, on postoperative days 1, 3, 5, 8, 12, 15, 22, 29, and 2 weeks thereafter until the IOP reached preoperative levels. Peak IOP, IOP net increase, and time to reach an IOP more than 20 mmHg in the two study groups were analyzed.

RESULTS

A total of 31 patients (20 male, 11 female) were examined. The mean age was 5.8 +/- 2.0 years (range, 2-10 years). Preoperative IOP in groups treated twice daily and four times daily were similar. After topical dexamethasone treatment, both groups showed a significant rise in peak IOP compared with preoperative values (twice daily, 25.2 +/- 6.8 mmHg vs. 14.3 +/- 2.4 mmHg, P < 0.001; four times daily, 28.7 +/- 6.9 mmHg vs. 14.3 +/- 2.9 mmHg, P < 0.001). The peak IOP was significantly higher in the four times daily group (P < 0.001), as was the net increase in IOP (twice daily, 10.9 +/- 5.8 mmHg vs. four times daily, 14.5 +/- 6.4 mmHg; P < 0.001). There was no difference in time for both groups to achieve the peak IOP, but the time to exceed its upper normal value (20 mmHg) was shorter in the four times daily group (twice daily, 12.3 +/- 9.1 days vs. four times daily, 10.0 +/- 7.4 days; P < 0.05).

CONCLUSIONS

In children treated with topical dexamethasone, ocular hypertension occurs in a dose-dependent manner. Children in the four times daily group had a quicker onset and more severe ocular hypertensive response than the twice daily group. Nevertheless, even the twice daily regimen produced significant IOP rise, suggesting that dexamethasone use in children should be avoided if possible, and it would be desirable to monitor the IOP twice weekly when it is administered to children.

Corneal laceration with total but isolated aniridia caused by a pecking injury

A 38-year-old man sustained a left eye injury after being attacked by a mynah bird. Ocular examination revealed a beak-shaped, full-thickness corneal laceration with total aniridia in the left eye. No other ocular injury was observed, and the lens and posterior segment remained normal over the subsequent 3 months. A penetrating keratoplasty was planned for visual restoration.

Scleral fixation of a capsular tension ring for severe ectopia lentis

A 4-year-old boy with bilateral idiopathic and progressive ectopia lentis had phacoaspiration of the lens and capsular tension ring (CTR) insertion in his left eye. Postoperatively, lens capsule centration remained poor. Single-point scleral fixation of the CTR was performed and centration of the lens capsule achieved. In-the-capsule intraocular lens (IOL) implantation was tried, but excessive IOL manipulation sliced open the capsule at the equator. Anterior vitrectomy and scleral IOL fixation were required. A similar approach was adopted in the right eye with meticulous attention given to gentle maneuvers. The operation was uneventful, with good IOL centration. Three and 11 months after surgery in the right and left eye, respectively, best corrected visual acuity was 20/50 in both eyes. Scleral fixation of the CTR, accompanied by gentle IOL manipulation, is an option to improve IOL centration in patients with severe zonular deficiency.

Isolated pedunculated congenital corneal dermoid

PURPOSE

To investigate a case of isolated pedunculated congenital corneal dermoid.

METHODS

Case report.

RESULTS

In a 14-day-old infant, the pedunculated portion of the dermoid was removed and confirmed by histopathologic examination. No surgical complication or recurrence was encountered, and the patient is waiting for a rotational autokeratoplasty.

CONCLUSIONS

Prompt treatment of such an unusual tumor is important to allow for visual rehabilitation and development.