A modular microfluidic platform to study how fluid shear stress alters estrogen receptor phenotype in ER+ breast cancer cells

Metastatic breast cancer leads to poor prognoses and worse outcomes in patients due to its invasive behavior and poor response to therapy. It is still unclear what biophysical and biochemical factors drive this more aggressive phenotype in metastatic cancer; however recent studies have suggested that exposure to fluid shear stress in the vasculature could cause this. In this study a modular microfluidic platform capable of mimicking the magnitude of fluid shear stress (FSS) found in human vasculature was designed and fabricated. This device provides a platform to evaluate the effects of FSS on MCF-7 cell line, an estrogen receptor positive (ER+) breast cancer cell line, during circulation in the vessels. Elucidation of the effects of FSS on MCF-7 cells was carried out utilizing two approaches: single cell analysis and bulk analysis. For single cell analysis, cells were trapped in a microarray after exiting the serpentine channel and followed by immunostaining on the device (on-chip). Bulk analysis was performed after cells were collected in a microtube at the outlet of the microfluidic serpentine channel for western blotting (off-chip). It was found that cells exposed to an FSS magnitude of 10 dyn/cm2 with a residence time of 60 s enhanced expression of the proliferation marker Ki67 in the MCF-7 cell line at a single cell level. To understand possible mechanisms for enhanced Ki67 expression, on-chip and off-chip analyses were performed for pro-growth and survival pathways ERK, AKT, and JAK/STAT. Results demonstrated that after shearing the cells phosphorylation of p-AKT, p-mTOR, and p-STAT3 were observed. However, there was no change in p-ERK1/2. AKT is a mediator of ER rapid signaling, analysis of phosphorylated ERα was carried out and no significant differences between sheared and non-sheared populations were observed. Taken together these results demonstrate that FSS can increase phosphorylation of proteins associated with a more aggressive phenotype in circulating cancer cells. These findings provide additional information that may help inform why cancer cells located at metastatic sites are usually more aggressive than primary breast cancer cells.

A modular microfluidic platform to study how fluid shear stress alters estrogen receptor phenotype in ER+ breast cancer cells

Metastatic breast cancer leads to poor prognoses and worse outcomes in patients due to its invasive behavior and poor response to therapy. It is still unclear what biophysical and biochemical factors drive this more aggressive phenotype in metastatic cancer; however recent studies have suggested that exposure to fluid shear stress in the vasculature could cause this. In this study a modular microfluidic platform capable of mimicking the magnitude of fluid shear stress (FSS) found in human vasculature was designed and fabricated. This device provides a platform to evaluate the effects of FSS on MCF-7 cell line, a receptor positive (ER+) breast cancer cell line, during circulation in the vessels. Elucidation of the effects of FSS on MCF-7 cells was carried out utilizing two approaches: single cell analysis and bulk analysis. For single cell analysis, cells were trapped in a microarray after exiting the serpentine channel and followed by immunostaining on the device (on-chip). Bulk analysis was performed after cells were collected in a microtube at the outlet of the microfluidic serpentine channel for western blotting (off-chip). It was found that cells exposed to an FSS magnitude of 10 dyn/cm2 with a residence time of 60 seconds enhanced expression of the proliferation marker Ki67 in the MCF-7 cell line at a single cell level. To understand possible mechanisms for enhanced Ki67 expression, on-chip and off-chip analyses were performed for pro-growth and survival pathways ERK, AKT, and JAK/STAT. Results demonstrated that after shearing the cells phosphorylation of p-AKT, p-mTOR, and p-STAT3 were observed. However, there was no change in p-ERK1/2. AKT is a mediator of ER rapid signaling, analysis of phosphorylated ERα was carried out and no significant differences between sheared and non-sheared populations were observed. Taken together these results demonstrate that FSS can increase phosphorylation of proteins associated with a more aggressive phenotype in circulating cancer cells. These findings provide additional information that may help inform why cancer cells located at metastatic sites are usually more aggressive than primary breast cancer cells.

Perspectives on tolerability and reasonableness

Judgements on tolerability and reasonableness are central to the optimisation of protection. There are currently several international developments regarding these key considerations which will contribute to the review and evolution of the system of radiological protection. The IRPA15 International Congress brought together the principal issues currently under discussion, and the outcome of these discussions is presented.

IRPA practical guidance for engagement with the public on radiation and risk

The International Radiation Protection Association, IRPA, promotes the worldwide enhancement of professional competence, radiation protection (RP) culture and practice by providing benchmarks of good practice, as well as encouraging the application of the highest standards of professional conduct, skills and knowledge for the benefit of individuals and society. Enhancing public understanding of radiation and risk is highlighted by experiences from past emergencies, including the accident at Tokyo Electric Power Company's (TEPCO) Fukushima Daiichi Nuclear Power Plant in 2011 and the following post-disaster recovery, as one of the most important challenges, and this challenge is common across almost all public interfaces regarding radiation and risk. To this end IRPA has been continuing a Task Group activity for Public Understanding since 2013. After a series of workshops in various regions of the world, the IRPA draft guidance was developed and issued for consultation of the Associate Societies in 2019. Through these processes, IRPA received a lot of helpful comments and suggestions. IRPA finally published 'Practical Guidance for Engagement with the Public on Radiation and Risk' on the IRPA website in October 2020. The objective of the guidance is two-fold. Firstly, it is to enthuse all of us in our profession to become more active public advocates for RP. Secondly, it is to provide information, experiences and techniques to help us to become more effective and comfortable in this challenging task. This paper provides a key summary of the published IRPA guidance.

Biophysical analysis of fluid shear stress induced cellular deformation in a microfluidic device

Even though the majority of breast cancers respond well to primary therapy, a large percentage of patients relapse with metastatic disease, for which there is no treatment. In metastasis, a tumor sheds a small number of cancerous cells, termed circulating tumor cells (CTCs), into the local vasculature, from where they spread throughout the body to form new tumors. As CTCs move through the circulatory system, they experience physiological forces not present in the initial tumor environment, namely, fluid shear stress (FSS). Evidence suggests that CTCs respond to FSS by adopting a more aggressive phenotype; however, to date single-cell morphological changes have not been quantified to support this observation. Furthermore, the methodology of previous studies involves inducing FSS by flowing cells through the tubing, which lacks a precise and tunable control of FSS. Here, a microfluidic approach is used for isolating and characterizing the biophysical response of single breast cancer cells to conditions experienced in the circulatory system during metastasis. To evaluate the single-cell response of multiple breast cancer types, two model circulating tumor cell lines, MDA-MB-231 and MCF7, were challenged with FSS at precise magnitudes and durations. As expected, both MDA-MB-231 and MCF7 cells exhibited greater deformability due to increasing duration and magnitudes of FSS. However, wide variations in single-cell responses were observed. MCF7 cells were found to rapidly deform but reach a threshold value after 5 min of FSS, while MDA-MB-231 cells were observed to deform at a slower rate but with a larger threshold of deformation. This behavioral diversity suggests the presence of distinct cell subpopulations with different phenotypes.

Protocol for a multicentre, prospective, observational cohort study of variation in practice in perioperative analgesic strategies in elective laparoscopic colorectal surgery: the LapCoGesic Study

INTRODUCTION

Laparoscopic surgery combined with enhanced recovery programmes has become the gold standard in the elective management of colorectal disease. However, there is no consensus with regard to the optimal perioperative analgesic regime in this cohort of patients, with a number of options available, including thoracic epidural spinal analgesia, patient-controlled analgesia, subcutaneous and/or intraperitoneal local anaesthetics, local anaesthetic wound infiltration catheters and transversus abdominis plane blocks. This study aims to explore any differences in analgesic strategies employed across the North East of England and to assess whether any variation in practice has an impact on clinical outcomes.

METHODS AND ANALYSIS

All North East Colorectal units will be recruited for participation by the Northern Surgical Trainees Research Association (NoSTRA). Data will be collected over a consecutive 2-month period. Outcome measures will include postoperative pain score, postoperative opioid analgesic use and side effects, length of stay, 30-day complication rates, 30-day reoperative rates and 30-day readmission rates.

ETHICS AND DISSEMINATION

Ethical approval for this study has been granted by the National Research Ethics Service. The protocol will be disseminated through NoSTRA. Individual unit data will be presented at local meetings. Overall collective data will be published in peer-reviewed journals and presented at relevant surgical meetings.

Developing the radiation protection safety culture in the UK

In the UK, as elsewhere, there is potential to improve how radiological challenges are addressed through improvement in, or development of, a strong radiation protection (RP) safety culture. In preliminary work in the UK, two areas have been identified as having a strong influence on UK society: the healthcare and nuclear industry sectors. Each has specific challenges, but with many overlapping common factors. Other sectors will benefit from further consideration.In order to make meaningful comparisons between these two principal sectors, this paper is primarily concerned with cultural aspects of RP in the working environment and occupational exposures rather than patient doses.The healthcare sector delivers a large collective dose to patients each year, particularly for diagnostic purposes, which continues to increase. Although patient dose is not the focus, it must be recognised that collective patient dose is inevitably linked to collective occupational exposure, especially in interventional procedures.The nuclear industry faces major challenges as work moves from operations to decommissioning on many sites. This involves restarting work in the plants responsible for the much higher radiation doses of the 1960/70s, but also performing tasks that are considerably more difficult and hazardous than those original performed in these plants.Factors which influence RP safety culture in the workplace are examined, and proposals are considered for a series of actions that may lead to an improvement in RP culture with an associated reduction in dose in many work areas. These actions include methods to improve knowledge and awareness of radiation safety, plus ways to influence management and colleagues in the workplace. The exchange of knowledge about safety culture between the nuclear industry and medical areas may act to develop RP culture in both sectors, and have a wider impact in other sectors where exposures to ionising radiations can occur.

Methods of haemostasis during liver resection--a UK national survey

BACKGROUND

Although haemorrhage is a major cause of morbidity and mortality in liver surgery, there is very little available guidance on its management.

METHODS

The aim of this study was to identify current practice in the UK in this regard. An online survey was created and hepatobiliary (HPB) specialists who were members of a specialist society and others who were known practitioners were invited by e-mail to complete the survey anonymously.

RESULTS

Fifty-one percent responded (n = 36/70), and most of these respondents worked at large HPB centres (>100 liver resections/year; n = 24, 66%). Not all questionnaires were fully completed by the individual surgeons. Thirty-eight percent of the surgeons routinely used Pringle's manoeuvre. Most surgeons used ligation of the inflow vessels (n = 16, 44%) and stapled the outflow vessels (n = 15, 42%). The Cavitron ultrasonic surgical aspirator (CUSA; 54%, 13/24) was preferred for parenchymal transection. The majority routinely used haemostatic adjuncts (n = 22, 62%), whilst 33% (n = 12) used them occasionally. Twenty-three (64%) felt manufactured haemostatic adjuncts played a major role in maintaining haemostasis and 19 preferred fibrin-based products.

CONCLUSION

The Pringle manoeuvre is a popular technique amongst specialist UK liver surgeons and the CUSA is used by nearly half of the surgeons. Despite the absence of definitive evidence for their benefit, manufactured haemostatic adjuncts are still widely used, especially the fibrin-based adjuncts.

Scena propylea (Druce) (Lepidoptera: Erebidae) an endemic species of Mexico

A revision of the bibliography, as well as an analysis on the data from the specimen labels of Scena propylea (Druce) (Erebidae: Arctiinae: Euchromiina) deposited in different scientific collections, was carried out and included information from 1894 to 2010. Its geographical distribution is restricted to the Trans-Mexican Volcanic Belt which determines this species as endemic. Data are provided on the biogeography, ecology and biology for this species. Its food plant is Thenardia floribunda (Apocynaceae) which is also endemic to Mexico. From this analysis, we propose the inclusion of both species in the document known as the Norma Oficial Mexicana 059 which encompasses the environmental protection of wild flora and fauna species native to Mexico and their risk categories, as well as the specifications for their inclusion, exclusion or change and a list of all species at risk.

Liver damage during organ donor procurement in donation after circulatory death compared with donation after brain death

Background

During the past decade the number of livers recovered and transplanted from donation after circulatory death (DCD) donors has increased significantly. As reported previously, injuries are more frequent during kidney procurement from DCD than from donation after brain death (DBD) donors. This aim of this study was to compare outcomes between DCD and DBD with respect to liver injuries.

Methods

Data on liver injuries in organs procured between 2000 and 2010 were obtained from the UK Transplant Registry.

Results

A total of 7146 livers were recovered from deceased donors during the study, 628 (8·8 per cent) from DCD donors. Injuries occurred in 1001 procedures (14·0 per cent). There were more arterial (1·6 versus 1·0 per cent), portal (0·5 versus 0·3 per cent) and caval (0·3 versus 0·2 per cent) injuries in the DBD group than in the DCD group, although none of these findings was statistically significant. Capsular injuries occurred more frequently in DCD than DBD (15·6 versus 11·4 per cent; P = 0·002). There was no significant difference between DCD and DBD groups in liver discard rates related to damage.

Conclusion

There were no differences in terms of vascular injuries between DCD and DBD livers, although capsular injuries occurred more frequently in DCD organs. Continuing the trend for increased frequency of DCD liver recovery, and ensuring that there is an adequately skilled surgical team available for procurement, is vital to improving the utilization of DCD livers.

Discharge reductions--value for money?

Through the Nuclear Liabilities Management Authority White Paper, the UK Government and the Regulators have signalled a commitment to further improving the operation of the regulatory regime and to its operating within the principles of proportionality, transparency, consistency and accountability which underpin the Government's approach to regulation in general. Particular emphasis is placed upon ensuring that there is greater consistency in the treatment of risk and hazard; proportionate and cost effective delivery of public, worker and environmental protection; and an open and transparently applied regulatory system. The paper uses the historical record of radioactive discharges from BNFL's Sellafield reprocessing site in the UK and seeks to identify what have been the key drivers for change, particularly over the past 20 years of significant discharge reductions. The paper examines the current context for ongoing and future discharges from the site, and the incorporation of the use of the concepts of best practicable environmental option and best practicable means. Intergovernmental commitments such as the OSPAR Sintra and Bremen statements and the developing UK policy framework are also considered, together with BNFL's work with a wide range of 'green' stakeholders. The paper outlines the principal components of BNFL's decision-making processes for discharge control and abatement; and how these interact with the relevant external pressures. It then analyses whether the overall drivers and outcomes align with the declared desire of the UK Government to ensure that the taxpayer receives value for money in the new national arrangements for managing historic nuclear liabilities.

Numerical Study and Economic Evaluation of SAGD Wind-Down Methods

Abstract

At a certain point in a SAGD operation, it is no longer economic to continue steam injection when the steam-oil ratio (SOR) becomes too high. A less energy intensive gas injection process following the SAGD process can prolong oil production by using the energy in place. Numerical studies of the injection of non-condensable gas, and a mixture of steam and non-condensable gas following a SAGD operation, were conducted using the CMG's STARS reservoir simulator. The simulation results suggest that, after three to five years of SAGD operation, when three quarters of the targeted reservoir is hot, it is appropriate to start a wind-down process. Injecting non-condensable gas results in a much lower production cost compared to continued steam injection; however, the oil production is reduced. Coinjection of steam with gas produces more oil than the gas-only injection process without substantially increasing the production cost. This is probably the desired wind-down process. Optimization is needed for the co-injection process. The choice of non-condensable gas depends on the cost and availability.

Introduction

The huge heavy oil and bitumen resources in Western Canada have motivated efforts to develop suitable recovery processes. One of the results of these efforts is the Steam-Assisted Gravity- Drainage (SAGD) process(1), which was proposed 20 years ago. The process utilizes horizontal wells and steam injection. The relatively slower gravity drainage is compensated for by using long horizontal wells, resulting in an economic production rate. In addition, the overall recovery may be as high as 70% of the original oil-in-place (OOIP). Much research has been conducted on the process in order to obtain a better understanding of the process under various reservoir conditions, to improve the accuracy on performance prediction, and to solve operational problems. After the process was pilot tested in AOSTRA's Underground Test Facility (UTF) and showed great promise(2, 3), SAGD has been regarded as one of the leading in situ recovery processes for heavy oil and bitumen resources. Many SAGD projects are in operation, under construction, or in the planning stages in Western Canada.

In the SAGD process, as the steam chamber grows, oil is gradually recovered, accompanied by an increasing steam-oil ratio. At a certain point, it is no longer economic to continue steam injection; however, the reservoir is still hot, and the energy in place can be utilized. Non-condensable gas (NCG) or a mixture of NCG and steam injection has been proposed as a wind-down process. A less energy-intensive gas injection process may maintain reservoir pressure, utilize the energy in place, and prolong oil production. Such a process has been field tested at the former UTF B patterns, and good results have been reported(8).

The purpose of this study is to evaluate various possible SAGD wind-down processes, and to find the appropriate time for starting a wind-down process. Using the reservoir simulator, STARS (Computer Modelling Group Ltd.), wind-down processes of the injection of NCG, and mixture of steam, and NCG were numerically investigated. It was found that the wind-down process could produce a considerable amount of oil.

Language and publication in "Cardiovascular Research" articles

BACKGROUND

The acceptance rate of non-mother English tongue authors is generally a lot lower than for native English tongue authors. Obviously the scientific quality of an article is the principal reason for publication. However, is editorial rejection purely on scientific grounds? English mother tongue writers publish more than non mother-tongue writers--so are editors discriminating linguistically? We therefore decided to survey language errors in manuscripts submitted for publication to Cardiovascular Research (CVR).

METHOD

We surveyed language errors in 120 medical articles which had been submitted for publication in 1999 and 2000. The language "error" categories were divided into three principal groups: grammatical, structural and lexical which were then further sub-divided into key areas. The articles were corrected without any knowledge of the author's nationality or the corrections made by other language researchers. After an initial correction, a sample of the papers were cross-checked to verify reliability.

RESULTS

The control groups of US and UK authors had an almost identical acceptance rate and overall "error" rate indicating that the language categories were objective categories also for the other nationalities. Although there was not a direct relationship between the acceptance rate and the amount of language errors, there was a clear indication that badly written articles correlated with a high rejection rate. The US/UK acceptance rate of 30.4% was higher than for all the other countries. The lowest acceptance rate of 9% (Italian) also had the highest error rate.

DISCUSSION

Many factors could influence the rejection of an article. However, we found clear indications that carelessly written articles could often have either a direct or subliminal influence on whether a paper was accepted or rejected. On equal scientific merit, a badly written article will have less chance of being accepted. This is even if the editor involved in rejecting a paper does not necessarily identify language problems as a motive for rejection. A more detailed look at the types and categories of language errors is needed. Furthermore we suggest the introduction of standardised guidelines in scientific writing.

Why barium enemas fail to identify colorectal cancers

BACKGROUND

The aim of the present study was to determine the cause and clinicopathological factors associated with the failure of barium enemas to detect colorectal cancers.

METHODS

A histopathological database was used to identify all patients with a diagnosis of colorectal cancer between 1991 and 1995. These records were matched with the records from patients who underwent barium enema examinations between 1990 and 1995. Those patients who had a colorectal cancer histologically diagnosed within 24 months of a barium enema in which no carcinoma was seen, were identified. Where possible the radiology was reviewed. Failure to identify a carcinoma was then attributed to either simple failure, technical, interpretive or perceptive difficulties.

RESULTS

There were 967 patients with colorectal cancers treated in Christchurch Hospital during the study period 1991-1995. Matching of these patient details with all barium enema records revealed 313 patients who had barium enemas and histologically proven colorectal cancer. There were 21 (6.7%) patients in whom a carcinoma was missed. Of these, 18 had a barium enema within 8 months of surgery, and three were performed outside this timespan (15, 18 and 28 months, respectively). On review, 11 carcinomas could not be identified (nine due to technical error: poor coating (n = 1), overlapping loops (n = 3), single-contrast enema (n = 4), faecal residue (n = 1)); and seven could be seen on review of the films (two interpretation errors, one technical and perceptive error, and four perceptive errors). In three cases films could not be found for review. In 16 of the 21 missed lesions the patient had a double-contrast barium enema (DCBE) while five patients had single-contrast barium enema (SCBE). The site and stage of missed tumours is presented.

CONCLUSIONS

The most common reason for missed tumours was technical. The percentage of missed tumours in each region of the bowel correlates with the known incidence of tumours in each region and with a normal Dukes stage distribution, except in the caecum where the number of missed lesions was higher than expected.

Toronto street youth and HIV/AIDS: prevalence, demographics, and risks

PURPOSE

The purposes of this study were: (a) to identify human immunodeficiency virus (HIV) prevalence in Toronto street youth through paired blood and saliva specimens; (b) to identify the HIV risk and prevention behaviors of street involved youth; and (c) to identify demographic or other factors that may contribute to the risk of street youth becoming infected with HIV/acquired immunodeficiency syndrome (AIDS) in the future.

METHODS

This was a cross-sectional convenience study of street-involved youth aged 14-25 years. The youth participated in interviews to identify HIV-related knowledge and personal risk and preventive behaviors. Following interviews, they were asked to provide a saliva sample, blood spot, or both. They could refuse one or both samples without jeopardizing their involvement or receiving an honorarium. Two males were the only participants who declined to provide a sample.

RESULTS

Fifteen of 695 (2.2%) youth tested positive for HIV infection. All were male, ranging in age from 18 to 25 years. Same and opposite sex, intravenous (IV) drug use, prostitution, and incarceration were risk factors associated with positive HIV test results. The rate of HIV infection was seven times greater for the group 20 years of age and older (20-25) compared to the younger group aged 14-9 years. The proportion testing positive for HIV from small cities, towns, and rural communities in Ontario was 40%; yet, they represented 21% of the study population. Most (57%) youth had been on their own for no more than 3 years and had moved frequently. Nearly two thirds (60%) had stayed in hostels or homeless shelters in the previous 6 months.

CONCLUSION

Street youth in Canada are at high risk of HIV infection with their risk increasing with age. Unprotected (same and opposite) sex, IV drug use, prostitution and incarceration were linked to their HIV infections. The high level of mobility identified by street youth challenges governments, communities, and public health officials to develop appropriate prevention strategies and to carefully monitor the spread of HIV infection in this vulnerable population.

Craniocervical junction tuberculosis: a rare but dangerous disease

BACKGROUND

Mycobacterium tuberculosis of the cervical spine is a rare but dangerous manifestation of extra-pulmonary tuberculosis. The clinical picture ranges from early, nonspecific, insidious symptoms to severe neurological complications and death, attributed to craniocervical junction instability and cervicomedullary compression. The different lines of management include antituberculous medication with traction and external fixation or adjunctive surgery (debridement and stabilization) in patients with severe or persistent neurological complications and/or vertebral instability.

METHODS

We describe two patients with advanced craniocervical junction tuberculosis. The early clinical picture was nonspecific in Case 1 and obscured by psychiatric illness in Case 2. The detailed clinical and radiological findings, and the management, will be described. Involvement of the occipital condyles and foramen magnum, which has not been reported previously, will be demonstrated.

RESULTS

Both cases underwent transoral biopsy, aspiration, and debridement of retropharyngeal abscess (granuloma). Histological and tissue culture studies proved the abscesses were tuberculous and anti-tuberculous medications were started. Case 1 showed complete resolution of the clinical and radiological findings. Case 2 developed cardiorespiratory arrest while in a halo jacket. He was resuscitated but remained quadriplegic and semiconscious; he developed nosocomial gram negative pneumonia. He was referred back to his local hospital where he died 1 year later.

CONCLUSIONS

Tuberculosis is an infrequent but notable cause of cervicomedullary compression. It should be suspected in patients with infective spondylitis who are immunocompromised or reside in an area highly endemic for tuberculosis. Management strategies include antituberculosis medication, transoral biopsy and drainage of the abscess, traction and external fixation, posterior decompression, and internal fixation, according to the clinical and radiological findings.

Relation of cigarette smoking to non-Hodgkin's lymphoma among middle-aged men

Because of previous inconsistencies in the observed relation of cigarette smoking to non-Hodgkin's lymphoma, this association was investigated in the Selected Cancers Study, a population-based case-control study of 1,193 non-Hodgkin's lymphoma cases and 1,903 controls, conducted between 1984 and 1988. Study subjects were men, and the median age of non-Hodgkin's lymphoma cases was 50 years (range, 32-60 years). As compared with the risk among men who had never smoked cigarettes, the risk among ever smokers was not increased (odds ratio (OR) = 1.05, p approximately 0.50), but the risk was significantly elevated among men who reported smoking > or = 2 1/2 packs per day and among men who had smoked for 30-39 years (OR = 1.45 in each group, p < 0.05). The estimated odds ratio among the 350 heavy smokers (> or = 50 pack-years) was 1.41 (95% confidence interval 1.08-1.85) after controlling for educational achievement, various occupational and medical exposures, and other potential confounders. The observed associations, however, tended to vary by age, with the odds ratio among heavy smokers decreasing from 2.8 among 32- to 44-year-olds to 1.1 among men over 55 years of age. These age-related differences, which may account for some of the inconsistencies seen in previous studies of cigarette smoking and non-Hodgkin's lymphoma, should be considered in future investigations.

Measurement of aging anxiety in an elderly Australian population

The purpose of this investigation was to modify an existing aging anxiety scale to produce an instrument specifically designed to assess aging anxiety in an elderly population. Existing instruments fail to consistently orientate aging associated threats into the future, and this poses a significant problem for the measurement of aging anxiety in the elderly population. It is proposed that this factor has confounded reports of the relationship between aging anxiety and advancing age. An existing valid and reliable instrument, the Anxiety about Aging Scale was modified for use with elderly respondents and tested on 123 independent community dwelling elderly individuals. The results indicated the modified scale provides a valid assessment of aging anxiety in the elderly.

Ethnicity and variation in breast cancer incidence

A breast cancer case-control study in Atlanta and 5 counties of central New Jersey involving interviews with 960 white and 281 black cases younger than 54 years of age enabled assessment of reasons for the varying incidence rates among these 2 ethnic groups. Of interest was why rates of breast cancer are higher among older white women, a trend that is reversed among very young women (<40 years). Calculation of the prevalence of exposure to classic and speculative risk factors and associated relative risks enabled derivation of population attributable risks (PARs) for the various combinations of age and ethnic groups. A higher PAR was derived for older (40-54 years) white (62%) than black (54%) women, which appeared to account for the observed difference in incidence between the 2 ethnic groups. Most of the difference in PARs between older whites and blacks was accounted for by whites having fewer births, later ages at first birth and slightly higher risks associated with reproductive and menstrual factors. Consideration of only well-established breast cancer risk factors showed a PAR among older whites of 57%, an estimate comparable to those previously published. Slightly higher overall PARs were derived when analyses considered several speculative but modifiable risk factors, including years of use of oral contraceptives, body size and alcohol consumption. Many of the analyses among younger women (20-39 years) were limited by available numbers, but it appeared that very little disease occurrence in young black women was associated with the factors studied.

Learning contracts in higher professional training: a user's guide

If the doctor undergoing higher professional training is to make best use of the attachment to a training location, and that training location is to make the most efficient use of the contribution of the trainee, then a written framework such as a learning contract can meet the needs of both. The first stage is to list the learning needs of the individual trainee and to match them with the work experience offered by the training location. Next, the work programme for the coming six to 12 months should be formalised in a learning contract, spelling out the tasks to be performed and the expected training benefit. This is then reviewed at agreed intervals and a written appraisal made. At the end of the attachment the trainee, trainer and any outside accrediting or auditing body, has a written account of what was expected, what was achieved, and the performance of trainee and trainer.

Atypical course of carotid cavernous sinus fistula in a six-year-old child

A case of post-traumatic carotid cavernous sinus fistula complicated by coma-producing intraventricular tamponade in a 6-year-old boy is reported. Urgent surgical treatment included external ventricular draining, trapping and muscle embolization by the Jaeger-Hamby procedure. Follow-up cerebral angiography showed complete obliteration of the fistula. The child made an excellent recovery and now leads a normal life.

The Women's Health Trial Feasibility Study in Minority Populations: design and baseline descriptions

The Women's Health Trial: Feasibility Study in Minority Populations (WHT:FSMP), a randomized trial of 2208 women, was conducted to investigate three questions. First, can women from minority and low-socioeconomic-status populations be recruited in numbers sufficient to evaluate a dietary intervention designed to lower fat intake. Second, the efficacy of a low fat, increased fruit/vegetable/ grain product intervention for reducing fat consumption. Third, will participation in the intervention lower plasma cholesterol and estradiol levels relative to the controls. The baseline results showed that an adequate number of minority and low SES women could be recruited to test the study hypotheses. A diverse study population of postmenopausal women consuming a high fat diet was recruited: 28% of participants were Black, 16% were Hispanic, 11% had less than a high school level of education, and 15.5% had household incomes of < $15,000.

Matrix metalloproteinases degrade myelin basic protein

Matrix metalloproteinases (MMPs) are a group of enzymes responsible for the degradation of interstitial connective tissue and basement membrane. The coding sequences for five of the human MMPs, viz. interstitial collagenase, 72 kDa gelatinase, stromelysin-1, matrilysin and 92 kDa gelatinase, were cloned and expressed in Chinese hamster ovary cells, and the proteins purified. The enzymes were compared for their ability to digest myelin basic protein, the major extrinsic membrane protein of central nervous system myelin. The most active on this substrate was 72 kDa gelatinase, followed by stromelysin-1; interstitial collagenase, matrilysin and 92 kDa gelatinase were of comparable but lesser activity. Production of these enzymes by glia or infiltrating inflammatory cells could therefore contribute to demyelination in neuroinflammatory disease.

Prevalence of human immunodeficiency virus and associated risk behaviour in injection drug users in Toronto

During 1989-90, interviews were conducted with 582 current injection drug users in the City of Toronto, 535 of whom also provided blood and/or saliva for anonymous unlinked HIV antibody testing. The rate of seropositivity identified was 4.3% (95% CI 3-6). The subjects were predominantly male, with a mean age of 28.3. The commonest drug of choice was cocaine (70%). Forty-six percent of the subjects reported using someone else's needle in the preceding six months, 60% of these indicating that they always cleaned it first. Eighty-one percent of those interviewed had been in jail at some time since they began injecting; 25% of these had injected while in custody, and of these 61% had shared injection equipment. Eighty-two percent of the men and 85.4% of the women reported opposite sex partners in the previous six months. Only about 20% of men reported consistent condom use, while 22% of females reported condom use at least 75% of the time.

Recruitment and retention of subjects for a longitudinal cancer prevention study in an inner-city black community

Recruiting and retaining subjects for longitudinal prevention trials is challenging. The inherent difficulties are compounded when the trial is to take place in a low-income minority community, since prevention is a low priority among residents of such communities, and research is viewed with suspicion. We present our experiences in attempting to recruit and retain low-income black women living in inner-city Atlanta for a trial of an educational intervention to promote screening for cancer. The intervention was conducted in the home by trained lay health workers. We found that recruitment was more successful when we recruited directly from the community than when we recruited from the patient registry of a primary health care center. The attrition rate over an 18-month period was high. Among members of the intervention group, those retained in the study tended to be wealthier and better educated and were more likely to be married and employed than those who dropped out. It seems probable that women of lower socioeconomic status found our intervention to be intrusive or burdensome. Among the controls, socioeconomic factors did not discriminate between those who completed the study and those who did not; loss to follow-up in this group was associated only with younger age. In conducting research of this type in low-income minority communities, special attention must be given to issues of recruitment and retention if the validity of the study is to be preserved.

The spectrum of intracranial aneurysms in pediatrics

Intracranial aneurysms are rare in children, accounting for merely 0.5-4.6% of all aneurysms. Several characteristics distinguish them from aneurysms in adults: male predominance; higher incidence of unusual location, such as peripheral or posterior circulation; and a greater number of large and giant aneurysms. These unique features can be attributed to the higher incidence of traumatic, infectious, developmental, and congenital lesions. Subarachnoid hemorrhage is not the exclusive mode of presentation; neuro-compressive signs and symptoms are also frequently seen. The treatment of intracranial aneurysms in pediatrics is dictated by their unusual pathology and liability to rehemorrhage. Although direct clipping has been the standard surgical technique, certain obsolete or innovative procedures should also be considered, such as entrapment, proximal occlusion, and endovascular embolisation, or even, in some cases, the non-invasive treatment of "watch and wait" for a spontaneous thrombosis. Six representative cases from King Faisal Specialist Hospital and Research Centre are reviewed. They reflect the diversity of the problem and the multi-disciplinary approach to the treatment.

Glutaric aciduria yype 1: First reported cases in three Saudi patients

The clinical and biochemical findings in three patients with glutaric aciduri Type 1 (GAT1) are presented. They had a normal postnatal period of three to 14 months. They developed sudden and severe encephalopathy following an infection or trauma (patient 3) that gradually progressed to severe dystonia, choreathetosis, spastic quadriplegia and mental retardation. Neuroradiologic studies of the brain revealed while matter disease and frontotemporal lobe hypoplasia. The urine findings by gas chromatography/mass spectrometry (GC)/(MS) were characteristic of GAT1. Since GAT1 is an organic acidemia without intermittent acidotic attacks, but primarily manifests with progressive encephalopathy, it is important to recognize the potential of its existence among handicapped children in chronic care facilities. The good clinical response in two of the patients urges early diagnosis in subsequent newborn siblings of the families with the disease. The diagnosis of three patients in less than two years indicate the need for neonatal screening for the recognition of this disease, among other treatable metabolic diseases, in Saudi Arabia.

Myelopathy after intrathecal chemotherapy. A case report with unique magnetic resonance imaging changes

BACKGROUND

Paraplegia caused by intrathecal chemotherapy has no known pathognomonic features and is a diagnosis of exclusion.

METHODS

The authors reported the clinical and neuroimaging findings in one patient with this syndrome.

RESULTS

The patient had severe paraplegia with urinary retention and impaired pain and touch sensation below T-10 with sparing of proprioception and vibration sense. Magnetic resonance imaging (MRI) scan showed diminished intensity throughout the central cervical spinal cord. Post-gadopentetate dimeglumine enhancement was scattered throughout the cervical spinal cord and in two areas of the dorsal spinal cord. Axial views of the cervical spinal cord showed that this enhancement was limited to the lateral columns.

CONCLUSIONS

The MRI in myelopathy due to intrathecal chemotherapy may show a unique pattern of postgadopentetate dimeglumine enhancement limited to the lateral columns of the spinal cord. However, two recently encountered patients with the same syndrome did not show similar changes.

The prevalence and spectrum of brain abnormalities in congenital choanal atresia

Over the past few years there has been increasing awareness of the association of congenital choanal atresia (CCA) with other congenital defects, including brain abnormalities. We obtained CT scans of the brain in twenty-three consecutive patients with CCA (10 boys and 13 girls) to determine the prevalence and the scope of associated brain abnormalities. CCA was associated with known syndromes or different congenital abnormalities in 7 and 10 patients, respectively, and was an isolated finding in 6 patients. Six patients (26%) had brain abnormalities including alobar holoprosencephaly, absent corpus callosum, benign enlargement of the subarachnoid space of infancy, cerebral calcification, small right hemisphere, small ventricles and microcephaly. None of the brain abnormalities were suspected clinically. Brain abnormalities were more common in boys compared to girls (40% vs 15.4%, p = 0.18), in bilateral compared to unilateral CCA (31.3% vs 14%, p = 0.38), and in membranous compared to bony CCA (75% vs 15.7%, p = 0.02). Brain abnormalities associated with CCA may be more common than generally recognized and more so in certain subgroups of patients. Obtaining a CT scan of the brain should be considered in all patients with CCA.

Treatment of small cell lung cancer in the elderly

OBJECTIVE

Since both the incidence of lung cancer and the proportion of the population over age 65 are increasing rapidly in North America, we undertook a retrospective review of elderly patients with small cell lung cancer (SCLC) in an attempt to assess the effect of age on treatment decisions, response, survival, and toxicity.

DESIGN

Retrospective chart view.

SETTING

Oncology Unit of a university-affiliated teaching hospital.

PATIENTS

There were 123 patients age > 70 years treated from 1976-88. Chemotherapy consisted of either cyclophosphamide, doxorubicin, and vincristine, or etoposide and cisplatin.

RESULTS

There were 74 patients aged 70-74, 35 aged 75-80, and 14 aged 80 years or older. No significant differences existed between the groups in sex, stage, performance status, or presence of co-morbid disease. Median survivals for patients with limited and extensive disease were 11.9 and 5.2 months, respectively (P = < 0.0001), with no significant difference for patients in any age group (P = 0.4). For both limited and extensive disease, survival correlated strongly with the treatment received. Twenty-five patients received no treatment (median survival 1.1 months), 20 had radiation only (median 7.8 months), and 27 patients had < 3 cycles of chemotherapy (median 3.9 months). Median survival for the 50 patients who had 4-6 cycles was 10.7 months (limited disease 15.0 months, extensive disease 8.61 months). In the Cox Model, survival correlated strongly with stage of disease and chemotherapy treatment (P < 0.0001), but only marginally with performance status (P < 0.077). Of the 77 patients who had chemotherapy, less than 50% in all age groups completed six cycles. Only two patients completed chemotherapy without a single dose reduction, and 76.7% required more than two reductions.

CONCLUSIONS

Chemotherapy should not be withheld from elderly patients with SCLC on the basis of age. The survival of patients who receive chemotherapy is significantly longer than that of untreated patients even though frequent dose reductions for toxicity may be required. The survival benefit is due to treatment effect and is not due to a selection bias in the cohort of patients chosen for therapy.

Seroprevalence of and risk factors for HIV-1 infection in injection drug users in Montreal and Toronto: a collaborative study

OBJECTIVE

To determine the prevalence of antibodies to HIV-1 and risk factors for HIV-1 infection among injection drug users.

DESIGN

Questionnaire survey. A venous blood sample was taken for HIV-1 antibody testing.

SETTING

Montreal and Toronto.

PARTICIPANTS

A total of 810 subjects who had used injection drugs in the previous 6 months recruited mainly from treatment centres and from the street in Montreal (425 subjects) and from treatment centres in Toronto (385 subjects) between September 1988 and September 1990. The overall participation rate was 82%.

OUTCOME MEASURES

HIV-1 seropositivity, sociodemographic and behavioural risk factors for HIV-1 infection.

RESULTS

The overall seroprevalence rate of HIV-1 infection was 4.8% (95% confidence limits [CL] 3.5 and 6.5). In Montreal the rate was 8.2% (95% CL 6.0 and 11.2), and in Toronto 1.0% (95% CL 0.4 and 2.6) (p < 0.001). Seropositive subjects were significantly older (p = 0.041) and were more likely to have a history of imprisonment (p = 0.006) than seronegative subjects. In univariate analysis seropositivity was associated with the following behaviours: more frequent cocaine use (p < 0.001), injecting drugs in "shooting galleries" (p = 0.002), sharing equipment with a person known to be HIV-1 seropositive (p = 0.006), "booting" fresh blood (p = 0.004), homosexual or bisexual orientation (p = 0.006), engaging in prostitution (p < 0.001) and, for men, number of male sexual partners in the previous 6 months (p = 0.007). In multivariate analysis the determinants of HIV-1 seropositivity were Montreal as the city of recruitment (odds ratio [OR] 6.7, 95% CL 2.32 and 19.42), engaging in prostitution (OR 2.13, 95% CL 1.01 and 4.75), a history of imprisonment (OR 3.51, 95% CL 1.33 and 9.29) and sharing equipment with a person known to be HIV-1 seropositive (OR 4.43, 95% CL 1.43 and 13.74).

CONCLUSIONS

Our findings show that HIV-1 is circulating among injection drug users in Montreal and Toronto and that both drug use and sexual behaviours are implicated in the transmission of infection in the populations studied. Adapted preventive programs should be developed to prevent further spread of HIV-1 infection in this population.

The development of airways obstruction in sarcoidosis among smokers and non-smokers

The prevalence of respiratory function abnormalities was studied in 32 patients with pulmonary sarcoidosis, 16 (50%) of whom were smokers. Airflow obstruction was found at presentation in one non-smoker and developed in four more during the course of follow-up. Similar airflow obstruction was present in six smoking patients and developed in four patients subsequently. Airways obstruction was a common physiological defect even in non-smokers, though smokers had more frequent airflow obstruction and developed a worse defect.

Evaluation of a brief telephone questionnaire to estimate fruit and vegetable consumption in diverse study populations

We evaluated the use of a six-item telephone questionnaire to estimate fruit and vegetable intakes in five diverse populations. Researchers administered the telephone questionnaire to persons who had previously undergone more extensive dietary assessment. The study population included 553 middle-aged and older adults in Beaver Dam, WI; 252 middle-aged and older women throughout Wisconsin; 150 parents of school children in Augusta, GA; 73 low-income, Hispanic mothers in Chicago, IL; and 51 older adults in Arizona. Spearman correlation coefficients between total fruit and vegetable intakes measured by the brief telephone survey and by more extensive food frequency questionnaires were 0.47 (Augusta), 0.48 (Arizona), 0.56 (Wisconsin), and 0.57 (Beaver Dam). Correlations between intakes measured by the brief telephone survey and by multiple diet records or recalls were 0.29 (Arizona), 0.46 (Chicago), and 0.54 (Beaver Dam). With the exception of Arizona, mean daily fruit and vegetable intakes measured by the telephone survey were similar to intakes estimated by multiple diet records or recalls and lower than those estimated by extensive food frequency questionnaires. Although caution may be needed in interpreting dietary reports from some ethnic subgroups, this brief telephone questionnaire may be useful for surveillance of fruit and vegetable intake in the United States.

Stapedial artery supplying sphenoid wing meningioma: case report

A 46-year-old woman presented complaining of resting tremor of the right arm and attacks of inappropriate crying and laughing. Computed tomography and magnetic resonance imaging of the head revealed a large left sphenoid wing meningioma. Preoperative cerebral angiography demonstrated a persistent stapedial artery, terminating as a middle meningeal artery which was the main blood supply to the tumour.

The accuracy of parental reports of their children's intake of fruits and vegetables: validation of a food frequency questionnaire with serum levels of carotenoids and vitamins C, A, and E

It has been recommended that U.S. children increase their dietary intake of fruits and vegetables. Measuring diets of children to support and evaluate nutritional interventions can be a difficult task, however. We administered to 97 parents of children age 6-10 years a food frequency questionnaire on their children's usual dietary intake over the previous 3 months. We then compared these reports by parents of their children's intakes of fruits and vegetables, and the derived estimates of intake of carotenoids and vitamins C, A, and E, with the children's serum levels of carotenoids and vitamins C, A, and E. The dietary reports of intakes of 35 fruits and vegetables showed Spearman rank-order correlations of 0.30 with serum carotenoids and 0.34 with serum vitamin C. Children in the highest quartile for intake of fruits and vegetables according to their parents' food frequency reports had 35% higher carotene levels and 31% higher vitamin C levels in their serum than did children in the lowest quartile for intake of fruits and vegetables. We conclude that parental reports of young children's diets using food frequency methods are accurate enough to be useful in nutritional screening and dietary surveillance of fruit and vegetable intake.

Assessing consumption of high-fat foods: the effect of grouping foods into single questions

Questionnaires on the frequency of consumption of foods are commonly used to measure dietary intake in epidemiologic research. To reduce the burden on respondents, questionnaires are often shortened by combining inquiries on similar foods into a single question. The effect of this practice on the reporting of dietary intake has never been investigated, however. To address this issue, we used two food frequency questionnaires in a telephone survey designed to rank adult residents of Alabama by their intake of dietary fat. One questionnaire included 29 questions about separate high-fat foods, whereas the other grouped these same foods into 14 questions. Compared with the 443 respondents interviewed using the 29-item separated-foods questionnaire, the 465 respondents responding to the 14-item grouped-foods questionnaire reported lower average intakes of the foods. In addition, a substantially higher percentage of respondents to the grouped-foods questionnaire reported never consuming the foods.

Renal cell cancer among paperboard printing workers

A physician's alert prompted us to investigate workers' cancer risk at a paperboard printing manufacturer. We conducted a retrospective cohort mortality study of all 2,050 persons who had worked at the facility for more than 1 day, calculated standardized incidence ratios (SIRs) for bladder and renal cell cancer, and conducted a nested case-control study for renal cell cancer. Standardized mortality ratios (SMRs) from all causes [SMR = 1.0, 95% confidence interval (CI) = 0.9-1.2] and all cancers (SMR = 0.6, 95% CI = 0.3-1.0) were not greater than expected. One bladder cancer and one renal cell cancer were included in the mortality analysis. Six incident renal cell cancers were observed, however, compared with less than two renal cell cancers expected (SIR = 3.7, 95% CI = 1.4-8.1). Based on a nested case-control analysis, the risk of renal cell cancer was associated with overall length of employment but was not limited to any single department or work process. Although pigments containing congeners of dichlorobenzidine and o-toluidine had been used at the plant, environmental sampling could not confirm any current exposure. Several limitations and a potential selection bias limit the inferences that can be drawn.

Congenital muscular dystrophy with abnormal radiographic myelin pattern

We report 11 children with a homogeneous clinical syndrome affecting both sexes, characterized by weakness at birth, slowly improving course, weakness of all muscle groups, arreflexia, elevated blood creatine kinase, normal nerve conduction velocity, dystrophic changes on muscle biopsy, and diffuse periventricular cortical white-matter abnormalities with sparing of corpus callosum, internal capsule, and brain stem. We compare them to 48 other previously reported similar cases and designate them as altered myelin radiographic pattern congenital muscular dystrophy (CMD), which is the same as occidental CMD. We compare them to the other presently accepted phenotypes: progressive Fukuyama CMD, Walker-Warburg or cerebral-ocular CMD, and Santavuori or muscle-eye-brain CMD. We suggest that the different phenotypes are alleles of the same gene, which regulates or expresses a structural protein required for muscle integrity, myelination, and formation of the cortex. Such phenotypic diversity has been established for mutations of Xp21 in X-linked muscular dystrophies.

Colonoscopically detected colorectal cancer missed on barium enema

The radiographs and clinical records of 26 patients with colorectal cancer missed on barium enema, and subsequently detected at colonoscopy, were reviewed to determine the cause of radiological error. Twenty (77%) of the patients were female. In 24 of 26 patients, anemia and/or rectal bleeding was a presenting feature. Fourteen of the 26 (54%) missed cancers were in the sigmoid colon, 10 (38%) in the ascending colon or hepatic flexure, and two (8%) in the rectum. Tumor size ranged from 20-100 mm. Fifteen were polyps, and 11 annular cancers. Fourteen (54%) were Dukes C or D tumors. Twenty-eight barium enemas in 23 patients were available for review: 86% were double-contrast studies. In 18 (76%), the cancer could be seen in retrospect and, in over half, the tumor was obvious. The dominant perceptive error was due to missing the lesion in the barium pool. Other major errors were missing the lesion en face or in overlapping loops. As most cancers were missed because of observer perceptive error, by both experienced and inexperienced radiologists, the authors recommend double reporting of all barium enemas.