bluuebunny/crossref_metadata_2025 huggingface dataset:
Should cancer patients be informed about their diagnosis and prognosis? Future doctors and lawyers differ
Authors: Elger B S , Harding T W
Published: October 2002

Objectives:To compare attitudes of medical and law students toward informing a cancer patient about diagnosis and prognosis and to examine whether differences are related to different convictions about benefit or harm of information.

Setting and design:Anonymous questionnaires were distributed to convenience samples of students at the University of Geneva containing four vignettes describing a cancer patient who wishes, or alternatively, who does not wish to be told the truth.

Participants:One hundred and twenty seven medical students and 168 law students.

Main outcome measures:Five point Likert scale of responses to the vignettes ranging from “certainly inform” to “certainly not inform” the patient.

Results:All medical students and 96% of law students favoured information about thediagnosisof cancer if the patient requests it. Seventy four per cent of medical students and 82% of law students favoured informing a cancer patient about his or herprognosis(p = 0.0003). Thirty five per cent of law students and 11.7% of medical students favoured telling about thediagnosis(p = 0.0004) and 25.6% of law students and 7% of medical students favoured telling about theprognosis(p < 0.0001) even if the patient had clearly expressed his wish not to be informed. Law students indicated significantly more often than medical students reasons to do with the patient’s good, legal obligations, and the physician’s obligation to tell the truth, and significantly less often than medical students that their attitude had been determined predominantly by respect for the autonomous choice of the patient.

Conclusion:Differences in attitudes according to the type of case and the type of studies were related to convictions about the benefit or harm to the patient caused by being given information. The self reported reasons of future physicians and future lawyers are helpful when considering means to achieve a better acceptance of patients’ right to know and not to know.
Response to Ronald M Perkin and David B Resnik: The agony of trying to match sanctity of life and patient-centred medical care
Authors: Kuhse H
Published: October 2002

Perkin and Resnik advocate the use of muscle relaxants to prevent the “agony of agonal respiration” arguing that this is compatible with the principle of double effect. The proposed regime will kill patients as certainly as smothering them would. This may lead some people to reject the argument as an abuse of the principle of double effect. I take a different view. In the absence of an adequate theory of intention, the principle of double effect cannot distinguish between the intentional and merely foreseen termination of life, and cannot rule out end-of-life decisions that are often regarded as impermissible.

What Perkin and Resnik are in effect saying is that there are times when physicians have good reasons to end a patient’s life—deliberately and intentionally—for the patient’s (and the family’s) sake. Why not say so—instead of going through the agony of trying to match sanctity of life and patient-centred medical care?
Glucose-6-phosphate dehydrogenase deficiency neonatal screening: preliminary evidence that a high percentage of partially deficient female neonates are missed during routine screening
Authors: Reclos G.J. , Hatzidakis C.J. , Schulpis K.H.
Published: October 2002

Objectives To provide preliminary evidence that the currently employed semiquantitative method of screening for glucose-6-phosphate dehydrogenase (G6PD) deficiency can only detect infants who are totally deficient for G6PD and misses all cases of partial G6PD deficiency.

Setting General population: 2150 randomly selected blood samples from the Blood Donation Department, Speliopouleion General Hospital, Athens, Greece. Neonate population: 2000 samples from neonates (50% male; 50% female) in maternity hospitals in the greater Athens area. High risk population: a total of 545 individuals from 133 families in the Athens area, the minimum acceptance criteria being the parents and any brother or sister.

Method Blood specimens from neonates or adults were collected and either spotted and dried on special filter paper (Schleicher and Schull 2992, Darmstadt, Germany) or used in tubes after being heparinised. For the quantitative evaluation of G6PD enzyme activity, the Quantase G6PD screening kit (Quantase Limited, Perth, UK) was used. Quantase G6PD controls (Quantase Limited) were used at three levels of G6PD. These controls are rated at 24, 30, and 37°C. Alternatively, we used the Sigma G6PDH controls (Sigma Chemical Company, St Louis, USA) which are rated at 30 and 37°C. The assay was performed according to the instructions included in the kit with the modification for haemoglobin normalisation.

Results General population: 36 females who were classified as having normal enzymatic activity with the semiquantitative test, were classified as partially deficient with the quantitative test. Neonate population: using the quantitative test, the percentage of G6PD deficient neonates in this population was 5.5%, compared with 3.17% reported in routine screening using the semiquantitative method. High risk population: the quantitative method detected 28 cases of total or partial G6PD deficiency in sisters of males with known total deficiency. The semiquantitative method only detected 32% (nine out of 28) of these cases.

Conclusions A considerable amount of partially G6PD deficient female neonates (heterozygotes) are undetected and classified as having normal enzymatic activity using the semiquantitative method, which uses a cut off of 2.1 U/g haemoglobin (Hb). The use of a fully quantitative G6PD screening kit is proposed, employing the automated haemoglobin normalisation and a cut off of 6.4 U/g Hb. Any neonate with an activity below this mark should be regarded as G6PD deficient, and all preventive measures should be taken.
Relocation of a static breast screening unit: a study of factors affecting attendance
Authors: Maxwell A.J.
Published: October 2002

Objective To assess the effect of relocation of an urban static breast screening unit on the attendance rates (uptake) in different parts of the catchment area.

Setting The Bolton Breast Screening Programme.

Methods The attendance rates for screening for patients in each of the seven Bolton postcode districts were obtained from the breast screening computer system for the 29 months prior to and 38 months following the relocation of the screening unit.

Results The overall attendance rate for screening in Bolton fell by 1%. The fall was most marked in BL1 (2.0%), the location of the original screening unit. BL4, the district housing the new unit, showed an increase in attendance of 1.1%. The other districts showed a similar trend with smaller reductions in attendances from districts that were closer to the screening unit than before, and vice versa. The direct distance between the centre of the women's home postcode district and the screening unit had a significant effect on the attendance rate (p = 0.045). For each kilometre further from the screening unit, the attendance decreased by approximately 2%. However, there was a 6.4% difference between the highest and lowest district attendance rates, the highest rates being in the less deprived areas.

Conclusions There is a significant inverse relationship between the distance a woman must travel for screening and her likelihood of attending. However, this has a relatively minor effect on attendance rates compared to that of socioeconomic factors.
Assay precision of serum α fetoprotein in antenatal screening for neural tube defects and Down's syndrome
Authors: Wald N.J. , Hackshaw A.K. , George L.M.
Published: October 2002

Objectives To assess the impact of current serum α fetoprotein (AFP) assays on the performance of screening for open neural tube defects and Down's syndrome.

Methods Maternal serum samples, collected between weeks 15 and 22 from 470 singleton pregnancies without neural tube defects or Down's syndrome, were assayed for AFP using an automated fluorometric immunoassay. The samples had been assayed for AFP using an in house radioimmunoassay with a lower precision ten years before. The variance of AFP using the radioimmunoassay was compared with that using the current fluorometric assay and then used to estimate the detection rates and false positive rates for neural tube defect and Down's syndrome screening.

Results Current serum AFP assays are more precise. Using a cut off level of 2.5 multiples of the median, the false positive rate in screening for anencephaly and open spina bifida was 0.8% with the new assay compared with 2% using the previous assay. When screening for Down's syndrome, the false positive rate is reduced by about one percentage point without loss of detection.

Conclusion Improvements in the precision of maternal serum AFP measurement have led to small but useful improvements in screening for open neural tube defects and Down's syndrome. Published estimates of screening performance using such modern assays can be revised accordingly.
Diagnosis of hypertrophic cardiomyopathy and screening for the phenotype suggestive of gene carriage in familial disease: a simple echocardiographic procedure
Authors: Devlin A.M. , Östman-Smith I.
Published: October 2002

Objectives To design a new echocardiographic method of screening for hypertrophic cardiomyopathy applicable to children and adults, with a low false positive rate in athletes.

Setting Regional centre of cardiology, Oxford, UK.

Methods Forty one patients with hypertrophic cardiomyopathy, 66 first degree relatives from families with familial hypertrophic cardiomyopathy, 262 normal subjects, and 32 athletes were studied by long axis M mode and cross sectional echocardiography to determine the frequency distribution of diastolic and systolic ratios of cardiac wall thickness to cavity diameter.

Results The best screening measure for hypertrophic cardiomyopathy is diastolic septum to cavity ratio, where a value of > 0.26 yielded a 100% disease detection rate at all ages with 0% false positives in the ordinary population. In comparison, the conventional screening tool of diastolic septum to posterior left ventricular wall ratio of > 1.5 yielded a detection rate of only 75%, for a false positive rate of 2%. In first degree relatives, a septum to cavity ratio > 0.26 yielded a 100% detection rate for an abnormal phenotype suggestive of carriage of a mutation for hypertrophic cardiomyopathy with no obvious false positives. Conventional screening showed a detection rate of only 44%. Athletes with physiological cardiac hypertrophy showed only a 6% false positive rate with diastolic septum to cavity ratio, and could be differentiated from subjects with hypertrophic cardiomyopathy by the absence of hypercontractility shown by a normal systolic left ventricular wall to cavity ratio (cut off < 0.63; 0% false positives).

Conclusions M mode echocardiographic measurement of the septum to cavity ratio provides a good screening test for hypertrophic cardiomyopathy at all ages. Combining this measurement with systolic left ventricular wall to cavity ratio improves the accuracy further.
Ten years of breast screening in the Screening Mammography Program of British Columbia, 1988–97
Authors: Olivotto I.A. , Kan L. , d'Yachkova Y. , Warren Burhenne L.J. , Hayes M. , Hislop T.G. , Worth A.J. , Basco V.E. , King S.
Published: October 2002

Objectives To evaluate 10 year outcomes of the Screening Mammography Program of British Columbia (SMPBC) and determine if breast screening targets were being achieved among women aged 40–80+ years.

Setting Organised breast screening programme in British Columbia, Canada.

Methods Rates of participation, abnormal referral, cancer detection, and interval cancer were calculated for asymptomatic women receiving an SMPBC mammography from 1988–97.

Results 895 849 screening mammographies were provided to 335 433 women. 51.3% of women were age 50–69 years. Abnormalities were identified on 57 454 screens (6.4%) from which 3304 cancers were detected. Abnormal call rates were higher on first (9.8%), compared with subsequent screens (4.4%) and declined with age: 7.7% at age < 40 to 5.4% for age 70–79 years. Cancer detection rates were higher on first (5.0 per 1000) compared with subsequent screens (2.8 per 1000) and increased smoothly with age from 1.4 to 8.2 per 1000 from age < 40 to age 80 years and older. Twenty per cent of cancers were non-invasive. The median size of invasive cancers was 14 mm and 81% had no axillary lymph node metastases. The 12 month interval cancer rate was 0.6 per 1000 and did not vary significantly with age or screening history. The prevalence to expected incidence ratio was 3.1 for women age 50–79 years.

Conclusion Across a broad range of ages, surrogate indices of screening mammography success have been achieved in a population based, North American, organised breast cancer screening programme.
Radiological review of incidence breast cancers
Authors: Moberg K. , Grundström H. , Lundquist H. , Svane G. , Havervall E. , Muren C.
Published: October 2002

Objectives To examine the rate of incidence cancers detectable on review of previous screening mammograms using two reviewing methods. To compare the results with a previous study of interval cancers using the same reviewing methods.

Setting Almost 50 000 women are regularly invited for service screening at Stockholm Söder Hospital. From 1989 to 1993, 119 women were identified with breast cancer detected at screening and the previous round attendance (incidence cancer).

Methods Screening mammograms, obtained before detection of the incidence cancers, were reviewed first mixed with other screening images (ratio 1:8) and then non-mixed. Reviewers from the screening unit responsible for the mammograms as well as reviewers from other units interpreted all images by both single and double reading.

Results The proportion detected on retrospective review varied between 5% and 50% depending on the review method used and the number of reviewers included to classify a case as truly identified. Generally more cancers were detected when non-mixed samples of mammograms were reviewed than when mixed samples were reviewed (mean increase 23%) and when interpreted by double reading compared with single reading (mean increase 14%).

Conclusions In an experimental retrospective set up, fewer incidence cancers were identified in mixed than in non-mixed review. Generally more incidence cancers were identified on review (22%) than previously reported for interval cancers (14%), probably reflecting differences in tumour biology and growth. How many women with potentially visible incidence cancers would have benefited from earlier tumour detection still needs to be evaluated.
The potential for a selective screening strategy for abdominal aortic aneurysm
Authors: Spencer C.A. , Jamrozik K. , Norman P.E. , Lawrence-Brown M.M.D.
Published: October 2002

Objectives To investigate the feasibility of selective screening for abdominal aortic aneurysm (AAA) based on identification of a target group of manageable size defined by risk factors for AAA.

Setting Male residents of Perth, Western Australia, aged 65–83 years, who participated in a randomised controlled trial of ultrasound screening for AAA.

Methods Eligible men were identified from the electoral roll and invited to attend a screening clinic. Those who attended completed a questionnaire, had a limited physical examination, and underwent an ultrasound examination to identify the maximum diameter of the infrarenal aorta. Data on risk factors collected from the first 8995 men seen were used to calculate a multivariate risk score for the remaining 2755 men who were screened. Centiles of the risk score were used to define potential target groups for screening and the sensitivity and specificity of each of these selective screening strategies were calculated. We repeated the calculation separately for AAAs of at least 30 mm, 40 mm, and 50 mm in diameter.

Results We found that screening half of the male population aged 65–83 years would find approximately 75% of AAAs, regardless of their size, whereas screening only current smokers in this population would find approximately 20% of AAAs.

Conclusions Selective screening for AAA using easily recognisable risk factors is feasible but is not worthwhile as approximately 25% of clinically significant cases would be missed.
Precision of risk in multidimensional likelihood ratio based screening with first trimester screening for Down's syndrome as a special case
Authors: Christiansen M. , Larsen S.O.
Published: October 2002

Objectives The development of computer programs for the calculation of risks and Monte Carlo estimation of the precision of such risks in likelihood ratio based screening with multiple gaussian distributed risk markers and a priori risks. A quantitative study of the variation of risk estimates in first trimester screening for Down's syndrome as a function of the variation of markers, and comparison of the results with published information on the variation of risk estimates in quality control schemes.

Methods Algorithms for calculations in the multidimensional normal distribution and procedures for Monte Carlo simulation of risk distributions were implemented in the S-PLUS programming language and used to construct programs producing risk estimates and risk distributions. Parameters of risk marker distributions and correlations were obtained from the scientific literature.

Results In screening for Down's syndrome during the first trimester the variation in risk estimates increased with increasing variation of biochemical and biometric markers, and the a posteriori risk may vary with at least a factor of 2–4.

Conclusions Risk estimates are not reasonable parameters in quality control systems. Instead, screening programmes should be controlled through careful monitoring of the distribution of risk estimates, in particular the screen positive rate, and control of the quality of the biochemical and biometric data. Furthermore, the correct classification of samples submitted for proficiency testing into screen positive and screen negative cases should be checked.
Cluster randomised controlled trial comparing the effectiveness and cost-effectiveness of two primary care interventions aimed at improving attendance for breast screening
Authors: Richards S.H. , Bankhead C. , Peters T.J. , Austoker J. , Hobbs F.D.R. , Brown J. , Tydeman C. , Roberts L. , Formby J. , Redman V. , Wilson S. , Sharp D.J.
Published: October 2002

Objectives To examine the effectiveness and cost-effectiveness of two interventions based in primary care aimed at increasing uptake of breast screening.

Setting 24 General practices with low uptake in the second round of screening (below 60%) in north west London and the West Midlands, UK. Participants were all women registered with these practices and eligible for screening in the third round.

Methods Pragmatic factorial cluster randomised controlled trial, with practices randomised to a systematic intervention (general practitioner letter), an opportunistic intervention (flag in women's notes prompting discussion by health professionals), neither intervention, or both. Outcome measures were attendance for screening 6 months after the practices had been screened and cost-effectiveness of the interventions.

Results 6133 Women were included: 1721 control; 1818 letter; 1232 flag; 1362 both interventions. Attendance data were obtained for 5732 (93%) women. The two interventions independently increased breast screening uptake in a logistic regression model adjusted for clustering, with the flag (odds ratio (OR) 1.43, 95% confidence interval (95% CI) 1.14 to 1.79; p=0.0019) marginally more effective than the letter (OR 1.31, 95% CI 1.05 to 1.64; p=0.015). Health service costs per additional attendance were £26 (letter) and £41 (flag).

Conclusions Although both interventions increased attendance for breast screening, the letter was the more cost-effective. Any decision to implement both interventions rather than just the letter will depend on whether the additional (£41) costs are judged worthwhile in terms of the gains in breast screening uptake.
Design of a multicentre randomised trial to evaluate flexible sigmoidoscopy in colorectal cancer screening
Authors: Atkin W.S. , Edwards R. , Wardle J. , Northover J.M.A. , Sutton S. , Hart A.R. , Williams C.B. , Cuzick J.
Published: October 2002

A randomised, controlled trial in progress in 14 United Kingdom and six Italian centres is evaluating screening for colorectal cancer using a single flexible sigmoidoscopy (FS) at around the age of 60 with removal during FS of all small adenomas, and colonoscopy for "high risk" polyps. The regimen aims to ensure that 95% of people (with either no polyps or only low risk polyps) complete the entire screening process in a single visit. This paper describes the rationale and design of the trial. Participants were patients aged between 55 and 64 on the lists of designated general practitioners (GPs) who were not excluded by their GP. A two stage recruitment procedure was employed to raise compliance rates in the intervention group. Potentially eligible persons were sent an "interest in screening" questionnaire; those who responded positively were randomised to the intervention or control groups. The trial is sufficiently large to estimate within narrow confidence intervals the magnitude of benefit and the duration of effect and optimum age for a single screen. It also examines the feasibility and acceptability of the screening regimen, and will identify training and quality assurance issues. Recruitment and screening are now complete and all baseline data have been collected. The first analysis of the effect on colorectal cancer incidence and mortality rates and suitability for a national screening programme can be expected in 2004.8
Long QT syndrome in children: the value of the rate corrected QT interval in children who present with fainting
Authors: Allan W.C. , Timothy K. , Vincent G.M. , Palomaki G.E. , Neveux L.M. , Haddow J.E.
Published: October 2002

OBJECTIVE:A strategy was evaluated for identifying a proportion of children with long QT syndrome (LQTS) using the rate corrected QT interval (QTc) to systematically evaluate children who faint. METHODS:QTc measurements and rates of fainting for the present analysis are available from families with KVLQT1, HERG, or SCN5A genotypes. QTc distributions in affected and unaffected children were documented and detection and false positive rates were modelled. RESULTS:The mean QTc (SD) in 117 affected children was 0.484 seconds (0.031), and 0.420 seconds (0.021) among 133 unaffected children. At a cut off of 0.49 seconds, QTc measurement will identify 42.5% of affected and 0.1% of unaffected persons with a history of fainting who are alive at the time of testing. Assumptions include a prevalence of 1:5000 for LQTS, 2% mortality with the first arrhythmia, and a rate of fainting of 50% in affected children and 7% in unaffected children. Given these variables, a QTc cut off of 0.49 seconds detects 42 of 200 affected, along with 70 unaffected children out of a population of 1 million. If QTc ≥0.49 seconds is found in either parent of children with a QTc of 0.44 through 0.48 seconds, another 21 affected and 25 unaffected children will be identified. CONCLUSION:Systematically performing QTc measurements as part of the evaluation of children who faint might optimally identify about one third of patients with LQTS with few false positives and thereby offer an opportunity to prevent some sudden deaths.
Does mammographic screening and a negative result affect attitudes towards future breast screening?
Authors: Drossaert C.H.C. , Boer H. , Seydel E.R.
Published: October 2002

OBJECTIVES:To investigate the impact of an experience of a benign mammographic result on intention to seek medical help immediately in the case of breast abnormalities, and on intentions and thoughts about future participation in screening. SETTING:The Dutch Breast Cancer Screening Programme for women aged 50–69. METHODS:Subjects were women who were invited for an initial breast examination: 223 women filled out a questionnaire about 10 days before and about 6 weeks after their initial breast examination. To be able to control for possible test effects, another group of 293 women filled out a questionnaire only after mammography. Changes in thoughts and intentions were examined. RESULTS:Most women were very satisfied with the course of their initial breast examination, although pain or discomfort was often mentioned. No clues to suggest false reassurance were found: more than 99% of the women would consider the possibility of breast cancer if they felt a lump in one of their breasts. In such a situation, most women intended to seek medical help within a week. These variables were not influenced by the experience of mammography with a benign result. In general, women were very positive about (repeat) participation, both before and after screening. After screening, the average woman perceived fewer costs in participating, and perceived her own ability to engage in future screening as higher. However, the experience of pain and anxiety during the initial screening did lead to reverse effects. Women who were less satisfied about their treatment by the staff were more likely to change their intentions to reparticipate in a negative way. CONCLUSIONS:As, in general, women became more positive about regular participation after they had attended breast cancer screening, efforts to improve first round attendance must be continued. At the same time, the screening organisations must continue to prioritise the high level of client friendliness throughout the screening. No evidence for detrimental effects of screening through false reassurance among participants was found.
Outcome of a school screening programme for carriers of haemoglobin disease
Authors: Lena-Russo D. , Badens C. , Aubinaud M. , Merono F. , Paolasso C. , Martini N. , Mattei J.F.
Published: October 2002

OBJECTIVES: To assess the impact of a screening programme for haemoglobinopathies which was organised from 1978 to 1985 in high secondary schools of the Marseille region. METHODS: Several variables that reflected the influence of this preventive programme on the uptake of prenatal diagnosis were investigated. To evaluate the partner’s uptake for the testing, a letter was sent, together with an anonymous questionnaire, to all the haemoglobin carriers detected in this programme. To evaluate the number of prenatal diagnoses, the charts of all couples from the Marseille area who underwent genetic counselling for haemoglobinopathies were compiled. The number of affected children born between 1980 to 2000 was recorded, and the cases in which one of the parents had previously been screened at school were noted. RESULTS: Half of the carriers replied to the questionnaire: 86% knew that they have to test their partner. Six carrier couples were identified, four asked for genetic counselling and requested eight prenatal diagnoses, two couples did not request genetic couselling and have had two affected children. CONCLUSIONS: Despite the time lapse between screening, informing, and pregnancy (mean 15 years), the information was well conserved and resulted in testing of the partner. The screening programme was effective in motivating requests for prenatal diagnosis.
Systemic sclerosis and occupational risk factors: a case–control study
Authors: Diot E , Lesire V , Guilmot J L , Metzger M D , Pilore R , Rogier S , Stadler M , Diot P , Lemarie E , Lasfargues G
Published: October 2002

Aims:A case–control study was carried out between 1998 and 2000 to investigate the relation between systemic sclerosis and occupational exposure.

Methods:Eighty cases of systemic sclerosis admitted consecutively to the Department of Internal Medicine at the University Hospital of Tours from 1998 to 2000 were included. For each case, two age, gender, and smoking habits matched controls hospitalised during the same period in the same department were selected. A committee of experts was set up retrospectively to assess occupational exposure. Exposure to silica dust and organic solvents (such as trichlorethylene and other chlorinated solvents, and benzene and other aromatic solvents) was investigated using semiquantitative estimates of exposure. An exposure score was calculated for each subject based on probability, intensity, daily frequency, and duration of exposure for each period of employment. The final cumulative exposure score was obtained, taking into account all periods of employment.

Results:Significant associations with SS were observed for crystalline silica, trichlorethylene, chlorinated solvents, toluene, aromatic solvents, ketones, white spirit, epoxy resins, and welding fumes. Risk of SS was significantly associated with a high final cumulative exposure score of occupational exposure to crystalline silica, trichlorethylene, chlorinated solvents, welding fumes, and any types of solvents.

Conclusion:Results confirm the influence of occupational risk factors in the occurrence of SS in both men and women. The link is not only with silica but also with other compounds such as solvents.
Management of colorectal cancer
Authors: Leslie A , Steele R J C
Published: October 2002

Colorectal cancer is the second most common cause of cancer death in the UK. Prompt investigation of suspicious symptoms is important, but there is increasing evidence that screening for the disease can produce significant reductions in mortality. High quality surgery is of paramount importance in achieving good outcomes, particularly in rectal cancer, but adjuvant radiotherapy and chemotherapy have important parts to play. The treatment of advanced disease is still essentially palliative, although surgery for limited hepatic metastases may be curative in a small proportion of patients.
Unusual cardiac manifestation of hypereosinophilic syndrome
Authors: Subhash H S , Asishkumar M , Jonathan M
Published: October 2002

Hypereosinophilic syndrome was diagnosed in a 14 year old girl who presented with recurrent syncope. An ambulatory electrocardiogram revealed intermittent type 2 second degree left atrioventricular (AV) block. Focal thinning of the interventricular septum was noted on echocardiography, contrary to the commoner finding of regional ventricular wall thickening among patients with hypereosinophilic syndrome. High grade AV block as a manifestation of hypereosinophilic syndrome is rare and focal thinning of the left ventricle as a manifestation of the syndrome has not been described earlier.
Multifocal cardiac leiomyosarcoma. Diagnosis and surveillance by transoesophageal echocardiography and contrast enhanced cardiovascular magnetic resonance
Authors: Clarke N R A , Mohiaddin R H , Westaby S , Banning A P
Published: October 2002

Primary cardiac sarcomas are rare and typically undergo aggressive local spread. There is no reliable definitive treatment, although radical surgical resection can provide palliation in the medium term. A case of a pleomorphic leiomyosarcoma with dramatic images is presented. The relative usefulness of transoesophageal echocardiography and cardiovascular magnetic resonance imaging to define the extent of tumour involvement, allowing planning of treatment, is demonstrated.
Trunk and main-branch development in Nothofagus pumilio (Nothofagaceae): a retrospective analysis of tree growth
Authors: Passo A , Puntieri J G , Barthélémy D
Published: October 2002

The development of the trunk and main branches of approximately 26-year-old Nothofagus pumilio (Poepp. et Endl.) Krasser trees was studied. The length and number of leaves of annual shoots were recorded for 56 trees from a natural population. Morphological and macroanatomical features allowed the identification of shoot apex deaths and the axillary positions from which branches and relay shoots derived. The trees had a mean height of approximately 6 m and a mean basal diameter of approximately 8 cm. The length of trunk shoots increased from the first years to the intermediate years of tree growth and decreased for the last 6 years of tree growth. The maximum length and number of leaves of trunk shoots were registered for the years around 1985, when tree age was about 17 years. The likelihood of apex death for trunk shoots was minimum for the period of maximum trunk shoot size. Despite the fact that the architectural features of the sampled trees corresponded to those of young, vigorously growing trees, they seemed to have reached a stage of low annual height growth. A sharp decrease in trunk shoot size occurred in 1992, a year in which rainfall during the growing season reached the minimum for the lifetime of the sampled trees. The size of shoots developed after 1992 was, on average, lower than that of shoots developed before 1992. Stressful conditions in this year may relate to meristem ageing and thus to the size of shoots formed in the following years. Main branches started their development with shoots similar to those of the trunk but were clearly differentiated from the trunk 5 years later. The differentiation between main branch and trunk shoots involved not only a lower shoot size but also a higher number of leaves per shoot length unit in main branch than in trunk shoots.Key words: Nothofagus pumilio, architectural analysis, shoot, trunk development, branching pattern, morphogenetic gradient.
Drought tolerance characteristics of black spruce (Picea mariana) seedlings in relation to sodium sulfate and sodium chloride injury
Authors: Redfield Edmund B , Zwiazek Janusz J
Published: October 2002

This study examined the feasibility of using water relations to screen black spruce (Picea mariana (Mill.) BSP) planting stock for salt tolerance, prior to planting in saline oil sands tailings. To do so, water relations parameters were derived from pressurevolume curves for individual seedlings prior to salt stress treatments. Pressurevolume curves were constructed for branches removed from the seedlings and the seedlings were subsequently treated with 60 mM NaCl, 120 mM NaCl, or 90 mM Na2SO4in solution culture. After 2 weeks of treatment, seedlings treated with NaCl solutions had greater needle electrolyte leakage and visible needle injury compared with equimolar and iso-osmotic solutions of Na2SO4, suggesting that chloride played a role in needle injury. At turgor loss point, a more negative osmotic potential was significantly correlated with lower electrolyte leakage in seedlings treated with Na2SO4but not in those treated with NaCl. The results suggest that, in contrast with NaCl, Na2SO4injury to black spruce seedlings may be largely due to osmotic stress and that drought tolerance parameters may be more helpful in predicting salt tolerance in plants treated with Na2SO4than in those treated with NaCl.Key words: osmotic stress, salt stress, drought tolerance, water relations, ion toxicity, black spruce.
Impact of flower harvesting on the salt marsh plant Limonium carolinianum
Authors: Baltzer Jennifer L , Reekie Edward G , Hewlin Heather L , Taylor Philip D , Boates J Sherman
Published: October 2002

Because of the potentially detrimental effects of seed production on adult survivorship and growth, moderate flower harvesting may have little negative impact on population growth of long-lived perennial plants such as Limonium carolinianum (Walter) Britton. We examined this by collecting data on survivorship, growth, and fecundity of an unharvested population over a period of 5 years and conducted a controlled experiment to examine the effect of harvesting on adult survivorship and growth over a 3-year period. Data were summarized in the form of a stage-structured matrix population model with a stochastic element that incorporated year-to-year variation in transition probabilities. Contrary to our original hypothesis, we found that preventing seed set through removal of flowers did not increase adult survivorship or growth. By determining the harvest level that reduced population growth rate to 1.0, we estimated the maximum sustainable harvest level to be 16%, a value that is approximately half that of reported harvest levels on accessible marshes in the study area. In spite of this, the reported harvest levels are unlikely to drive local populations to extinction in the foreseeable future. Providing the adult population size is >100 and harvest levels are <90%, time to local extinction will exceed 100 years. This is a function of the very high survivorship of adults in this species and the fact that harvesting has no negative impact on adult survivorship or growth. However, because of the long preadult phase in this species (89 years) and the fact that fecundity of young adults is low, recovery from overharvesting is extremely slow. Adult population size can be reduced to 25% of its original value in 7 years at high harvest levels, but it will take 34 years on average to recover once harvesting is terminated.Key words: cost of reproduction, stagestructures matrix population model, sustainable harvest, conservation of biodiversity.
Trade-off between growth ability and stress tolerance in Leymus mollis (Poaceae) along a subarctic coastal dune sequence in northern Quebec
Authors: Houle Gilles
Published: October 2002

Several environmental factors vary with distance from the shoreline on coastal dunes. For instance, salinity, salt spray, and sand movement decrease but nutrient and water availability increase from the foredune to the stabilized dunes. Plants colonizing the upper beach and the foredune are thus exposed to more severe abiotic stresses than those on the stabilized dunes. Although community composition changes progressively from the upper beach to the stabilized dunes, some species persist through the sequence. For example, on the coastal dunes of subarctic Quebec, Leymus mollis (Trin.) Hara (Poaceae), a perennial grass that colonizes the upper beach and the foredune, persists onto older stabilized dunes. Under controlled conditions, the response of L. mollis ramets from different habitats along the dune sequence to various saline conditions was examined. It was expected that ramets from the upper beach and the foredune, where substrate salinity is typically higher, salt spray more important, and saltwater intrusion more frequent, to better support salinity stress. Ramets from the upper beach and the foredune had a higher relative growth rate (RGR) but were, in fact, less tolerant to salt stress than those from the stabilized dune. Because sand accumulation is higher on the upper beach and the foredune, a higher RGR may be favored there to the detriment of a higher sensitivity to salt stress. The salt tolerance of stabilized dune ramets may be the expression of a more generalized stress-tolerance strategy as suggested by low RGR and high leaf nutrient concentration.Key words: embryo dune, foredune, leaf turnover, relative growth rate (RGR), salt stress, stabilized dune, tolerance, trade-off.
Occurrence of phi thickenings is correlated with gymnosperm systematics
Authors: Gerrath Jean M , Covington Lori , Doubt Jennifer , Larson Douglas W
Published: October 2002

Phi thickenings are lignified wall thickenings in the radial and tangential walls of the root cortex of some plant species and are so named because they resemble the Greek letter phi in cross section. Although their occurrence has long been known in gymnosperms, a systematic survey of their presence has never been undertaken. Such a survey may be useful to future studies of the functions of these structures. Roots of 22 species of gymnosperms representing all of the major groups were hand sectioned, stained with phloroglucinol (a lignin stain), and examined for the presence of phi thickenings using light microscopy. Detailed observations on Thuja occidentalis (Cupressaceae) were made to provide a baseline for comparison in this study. Phi thickenings were absent in the species examined in the Cycadaceae, Gnetaceae, Pinaceae, and Podocarpaceae and were present in the Ginkgoaceae, Araucariaceae, Taxaceae, and Cupressaceae (s.l.). These results, when combined with previous literature reports, indicate that the occurrence of phi thickenings is consistent within a family. Their occurrence is also correlated with current hypotheses of phylogenetic relationships within the gymnosperms, which may indicate their usefulness as a systematic character.Key words: phi thickenings, root anatomy, gymnosperms.
Geochronologic and thermobarometric constraints on the metamorphic history of the Fairbanks Mining District, western Yukon-Tanana terrane, Alaska
Authors: Douglas Thomas A , Layer Paul W , Newberry Rainer J , Keskinen Mary J
Published: October 2002

This study presents new petrologic and thermochronologic information from the Fairbanks district of east central Alaska that indicate a complex metamorphic and structural history for the western YukonTanana terrane. Garnetbiotite and garnetpyroxene thermometry and jadeite barometry yield prograde temperatures and pressures for the Chatanika eclogite (523°C, 1415 kbar (1 kbar = 100 MPa)). Cooling from peak eclogitization is estimated from 40Ar/39Ar single grain geochronology at ~210180 Ma. Secondary white mica ages of 140115 Ma along the fault contact between eclogite and underlying lower amphibolite-facies rocks constrain the age of the event that placed the Chatanika eclogite over the Fairbanks schist. Based on observations from field mapping and diamond drill samples, we interpret this structural contact as a thrust fault. Garnetbiotite mineral pairs are reset by as much as 200°C within this fault zone. Biotite and white mica ages of ~100110 Ma, combined with Jurassic amphibole ages in Fairbanks schist samples, indicate the Fairbanks schist and Chatanika eclogite cooled through biotite and white mica argon closure temperatures in the early Cretaceous. Intrusion of mid-Cretaceous, calc-alkalic, gold-related granitic plutons in the Fairbanks district are evidenced by loss of radiogenic argon in many of the 40Ar/39Ar age fractions. Eocene basalt is visible in six widely separated localities within the eastern part of the Fairbanks district. However, the pervasiveness of a 50 Ma resetting event in samples as far as 30 km from present day basalt localities indicates the Eocene flows were either deposited throughout the Fairbanks area or are associated with large plutons at depth.
The age of the Gunflint Formation, Ontario, Canada: single zircon UPb age determinations from reworked volcanic ash
Authors: Fralick Philip , Davis Don W , Kissin Stephen A
Published: October 2002

The Gunflint Formation, a Paleoproterozoic chemicalclastic sedimentary assemblage outcropping to the immediate northwest of Lake Superior, became famous in 1954 as containing the oldest fossil assemblage known at that time. Older microfossils have since been discovered, but the Gunflint procaryotes remain one of the most diverse Precambrian fossil communities. The finding of possible multicellular organisms in correlative lithic units in Michigan has recently added to the need for an exact age of the Formation. Zircons were extracted from rainout and storm reworked volcanoclastic beds in the upper portion of the Gunflint Formation. A euhedral zircon population has yielded a 1878.3 ± 1.3 million years BP UPb age, believed to be nearly synchronous with the depositional age. This not only provides a precise age for the community of organisms, but also strongly supports a back-arc extensional setting for the Animikie Basin, rather than a foreland trough.
Estimating salmon stockrecruitment relationships from catch and escapement data
Authors: Schnute J T , Kronlund A R
Published: October 2002

This paper presents an analysis of stockrecruitment data that takes account of natural variation in stock productivity (process error) and inaccurate escapement counts (measurement error). We formulate the model using dynamic state variables and take advantage of related techniques for parameter estimation, such as an extended Kalman filter. Our recruitment function depends explicitly on parameters relevant to management and includes various cases of historical interest. We adopt Bayesian methods for assessing uncertainty and use Markov chain Monte Carlo (MCMC) techniques to obtain posterior samples. A worked example, based on simulated data, illustrates geometric relationships among model choices, estimated recruitment curves, and data interpretations.
The link between precipitation, river runoff, and blooms of the toxic dinoflagellate Alexandrium tamarense in the St. Lawrence
Authors: Weise Andréa M , Levasseur Maurice , Saucier François J , Senneville Simon , Bonneau Esther , Roy Suzanne , Sauvé Gilbert , Michaud Sonia , Fauchot Juliette
Published: October 2002

Blooms of the toxic dinoflagellate Alexandrium tamarense, which is responsible for paralytic shellfish poisoning, are annually recurrent events in the Estuary and Gulf of St. Lawrence, Québec, Canada. The analysis of abundance data for this algal species between 1989 and 1998 at Sept-Îles, a presumed initiation site in the north western Gulf of St. Lawrence, revealed yearly fluctuations in the onset, duration, and magnitude of toxic A. tamarense blooms. Hydrological and meteorological data for the region indicate that rainfall, Moisie River runoff, and wind are highly related to the pattern of bloom development each year. Results from the 10-year data set reveal that in this system: (i) high Moisie River runoff from a prolonged spring freshet or from heavy rainfall events in the summer and fall can initiate A. tamarense blooms; (ii) high Moisie River runoff combined with prolonged periods of weak winds (<4 m·s1) favour the continued development of blooms; and (iii) winds >8 m·s1 disrupt blooms. Salinity, which reflects the general state of the water column in terms of freshwater input and stability, had a strong negative correlation with the probability of observing A. tamarense cells at this station and could thus be used as a predictive tool for the presence of cells in this system.
Effects of temperature and salinity on survival of young-of-the-year Hudson River striped bass (Morone saxatilis): implications for optimal overwintering habitats
Authors: Hurst Thomas P , Conover David O
Published: October 2002

We examined the role of salinity, body size, and energetic state in determining low temperature tolerance of young-of-the-year (YOY) striped bass (Morone saxatilis) and used this information to map optimal overwintering habitat in the Hudson River estuary. A long-term experiment compared survival at 15 ppt and 30 ppt. In additional experiments, winter-acclimated fish were exposed to temperature declines (2.3°C·day1to 1°C·week1) at salinities from 0 ppt to 35 ppt. Highest survival at low temperatures was consistently observed at intermediate salinities. These results suggest that the observed distribution of overwintering striped bass is related to physiological constraints on osmo regulatory ability at low temperatures. Low temperature tolerance appeared unrelated to body size and energetic state. Salinity profiles were used to describe the location and extent of optimal wintering habitats under various hydrographic regimes. The location of optimal habitats was displaced by over 27 km along the river axis because of variation in salinity regime. Changes in the availability of optimal habitat may be responsible for variation in recruitment to the Hudson River population. These results demonstrate the need to consider a holistic approach encompassing all seasons of the year in assessing habitat requirements of fishes.