Unveiling Disparities: Exploring Differential Attainment in Postgraduate Training Within Clinical Oncology

AIMS

Differential attainment (DA) in post graduate medical training is a recognised challenge and refers to unexplained variation across groups when split by several protected characteristics. The Royal College of Radiology is committed to fostering diversity, inclusivity, and equality with the goal of narrowing existing gaps and improving training outcomes.

MATERIALS AND METHODS

This was a mixed methods study aiming to understand the causes of DA with view to helping the RCR develop strategies to address this. A cross-sectional survey was completed by 140 clinical oncology trainees in September 2022. Trainees and trainers (17 and 6 respectively) from across England, Scotland, Wales and Northern Ireland, took part in focus group and interviews from August to December 2022. Quantitative and qualitative data merged and interpreted.

RESULT

Results showed international medical graduates and trainees from ethnic minority backgrounds were more likely to encounter challenges. The qualitative findings were used to identify three themes through which these problems could be framed. The trainee as a "space invader," the hidden curriculum of clinical oncology training and the process of navigating and tacking the training journey.

CONCLUSION

Differential attainment is the product of a complex interplay between the trainee, trainer, and the training environment. Therefore, interventions must be tailored to different people and contexts. At a national level, the RCR can adopt general policies to promote this such as mentorship programmes, protected time for supervision and cultural competency training. Efficacy of proposed interventions for trial and their impact on DA should be evaluated to drive evidence-based changes.

Biomechanical and ergonomic risks associated with cervical musculoskeletal dysfunction amongst surgeons: A systematic review

INTRODUCTION

Surgeons are at high risk of developing musculoskeletal symptoms due to a range of factors including, maladaptive positioning and surgical ergonomics. Cervical muscle strain and biomechanical load is most prevalent due to repetitive motions and prolonged static neck positioning. This issue is apparent through reports of prevalence between 10 and 74.4% among surgeons. The aim of this systematic review is to provide an objective assessment of the clinical evidence available and a descriptive analysis of the effects of kinematics and surgical ergonomics on the prevalence of surgeons' cervical musculoskeletal pain.

METHODS

This is PRISMA-compliant systematic review of clinical studies assessing the prevalence of cervical musculoskeletal dysfunction in surgeons by searching PUBMED and Ovid EMBASE databases from inception to 19th October 2023. Study quality was graded according to the National Institutes of Health study quality assessment tools.

RESULTS

A total of 9 studies were included in the final qualitative analysis. The use of loupes, open surgery and excessive neck flexion (>30°) were associated with cervical dysfunction. Comparison of study outcomes was challenging due to heterogeneity within study methods and the paucity of methodological quality.

CONCLUSION

The current literature assessing ergonomic and biomechanical factors predisposing surgeons to cervical musculoskeletal dysfunction is insufficient to provide reliable guidance for clinicians. Although the literature identifies factors contributing to work-related cervical dysfunction, few attempt to evaluate interventions for improved surgical ergonomics. An objective assessment of interventions that prompt postural correction with the aim to improve neck pain in surgeon cohorts is warranted.

Inhibitors of the NMDA-Nitric Oxide Signaling Pathway Protect Against Neuronal Atrophy and Synapse Loss Provoked by l-alpha Aminoadipic Acid-treated Astrocytes

The impact of treating astrocytes with the astrocytic toxin l-alpha amino adipic acid (L-AAA) on neuronal outgrowth, complexity and synapse formation was assessed, using a model of astrocyte-neuronal interaction. Treatment of rat primary cortical neurons with conditioned media (CM) derived from astrocytes treated with L-AAA reduced neuronal complexity and synapse formation. L-AAA provoked a reduction in the expression of glial fibrillary acid protein (GFAP) and a reduction in ATP-linked mitochondrial respiration in astrocytic cells. As the NMDA-R/PSD-95/NOS signaling pathway is implicated in regulating the structural plasticity of neurons, treatment of neuronal cultures with the neuronal nitric oxide synthase (nNOS) inhibitor 1-[2-(trifluoromethyl)phenyl] imidazole (TRIM) [100 nM] was assessed and observed to protect against L-AAA-treated astrocytic CM-induced reduction in neuronal complexity and synapse loss. Treatment with the NMDA-R antagonist ketamine protected against the CM-induced loss of synapse formation whereas the novel PSD-95/nNOS inhibitors 2-((1H-benzo[d] [1,2,3]triazol-5-ylamino) methyl)-4,6-dichlorophenol (IC87201) and 4-(3,5-dichloro-2-hydroxy-benzylamino)-2-hydroxybenzoic acid (ZL006) protected against synapse loss with partial protection against reduced neurite outgrowth. Furthermore, L-AAA delivery to the pre-limbic cortex (PLC) of mice was found to increase dendritic spine density and treatment with ZL006 reduced this effect. In summary, L-AAA-induced astrocyte impairment leads to a loss of neuronal complexity and synapse loss in vitro and increased dendritic spine density in vivo that may be reversed by inhibitors of the NMDA-R/PSD-95/NOS pathway. The results have implications for understanding astrocytic-neuronal interaction and the search for drug candidates that may provide therapeutic approaches for brain disorders associated with astrocytic histopathology.

Bacteraemia in the ED: Are We Meeting Targets?

AIM

An audit was performed in an Irish Emergency department (ED) to evaluate adherence to established antimicrobial guidelines and to determine the most common presentations of sepsis.

METHODS

Data on ED patients with clinically significant bacteraemia on blood cultures were recorded for three months . The antimicrobial given to the patient was compared to that which the hospital guidelines would recommend for the ED diagnosis.

RESULTS

Eleven patients out of 53 had no antimicrobial guidelines for diagnosis. Of the 42/53 patients, non-adherence to antimicrobial guidelines by physicians was observed in 81% (n=34/42) patients and adherence was observed in 19% (n=8/42) patients. Escherichia coli 35.70% (n=18), was the most frequent organism isolated.

CONCLUSIONS

Non-adherence to antimicrobial guidelines resulted in 68% (n=23/34) of organisms covered by the antibiotic. Adherence to antimicrobial guidelines resulted in 87% (n=7/8) of organisms covered by the antibiotic.

Advances in the synthesis of acyclic peroxides

This review summarises the many developments in the synthesis of acyclic peroxides, with a particular focus on the past 20 years, and seeks to update organic chemists about these new approaches.

Anticholinergic burden in schizophrenia and ability to benefit from psychosocial treatment programmes: a 3-year prospective cohort study

BACKGROUND

Many medications administered to patients with schizophrenia possess anticholinergic properties. When aggregated, pharmacological treatments may result in a considerable anticholinergic burden. The extent to which anticholinergic burden has a deleterious effect on cognition and impairs ability to participate in and benefit from psychosocial treatments is unknown.

METHOD

Seventy patients were followed for approximately 3 years. The MATRICS consensus cognitive battery (MCCB) was administered at baseline. Anticholinergic burden was measured with the Anticholinergic Cognitive Burden (ACB) scale. Ability to benefit from psychosocial programmes was measured using the DUNDRUM-3 Programme Completion Scale (D-3) at baseline and follow-up. Psychiatric symptoms were measured using the PANSS. Total antipsychotic dose was measured using chlorpromazine equivalents. Functioning was measured using the Social and Occupational Functioning Assessment Scale (SOFAS).

RESULTS

Mediation analysis found that the influence of anticholinergic burden on ability to participate and benefit from psychosocial programmes was completely mediated by the MCCB. For every 1-unit increase on the ACB scale, change scores for DUNDRUM-3 decreased by -0.27 points. This relationship appears specific to anticholinergic burden and not total antipsychotic dose. Moreover, mediation appears to be specific to cognition and not psychopathology. Baseline functioning also acted as mediator but only when MCCB was not controlled for.

CONCLUSIONS

Anticholinergic burden has a significant impact on patients' ability to participate in and benefit from psychosocial treatment programmes. Physicians need to be mindful of the cumulative effect that medications can have on patient cognition, functional capacity and ability to benefit from psychosocial treatments.

The burden of illness in patients with hyponatraemia in Sweden: a population-based registry study

BACKGROUND

Hyponatraemia (HN; serum sodium level < 135 mmol/l) is the most common electrolyte disturbance seen in clinical practice, and is associated with varying spectrum of symptoms. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common aetiology in hospitalised patients, and can be caused by several different underlying conditions.

AIMS

The objectives of this study were to retrospectively examine the baseline characteristics, clinical outcomes and hospital resource utilisation of patients with HN and/or SIADH in Sweden over a 10-year period from 2001 to 2011. Additional analysis was performed on subpopulations of patients with hip fracture, pneumonia and small cell lung cancer (SCLC) to see if trends in outcomes were consistent across a broad range of aetiologies commonly associated with the condition.

METHODS

Patient information was taken from the Swedish National Patient Registry, the Swedish Cancer Registry, the Swedish Cause of Death Register and the Swedish Prescribed Drug Register. A total of 34,537 patients (4.38%) were identified with HN and/or SIADH, with the incidence and prevalence rising over the 10-year study period.

RESULTS

Of the 34,537 patients identified, 841 had hip fracture, 2635 had pneumonia and 106 had SCLC. Compared with matched control patients, those with HN and/or SIADH had a longer length of hospital stay, a higher re-admission rate and a shorter time to re-admission.

CONCLUSIONS

This study showed that HN and/or SIADH negatively impact patient outcomes and healthcare resources related to hospital stay irrespective of the underlying cause. The impact of HN is not confined to the initial hospitalisation, as re-admission rates are also affected.

Developing WHO guidelines with pragmatic, structured, evidence-based processes: A case study

Many guidelines, including those produced by the World Health Organisation (WHO), have failed to adhere to rigorous methodological standards. Operational examples of guideline development processes may provide important lessons learned to improve the rigour and quality of future guidelines. To this end, this paper describes the process of developing WHO guidelines on prevention and care interventions for adults and adolescents living with HIV. Using a pragmatic, structured, evidence-based approach, we created an organising committee, identified topics, conducted systematic reviews, identified experts and distributed evidence summaries. Subsequently, 55 global HIV experts drafted and anonymously submitted guideline statements at the beginning of a conference. During the conference, participants voted on statements using scales evaluating appropriateness of the statements, strength of recommendation and level of evidence. After review of voting results, open discussion, re-voting and refinement of statements, a draft version of the guidelines was completed. A post-conference writing team refined the guidelines based on pre-determined guideline writing principles and incorporated external comments into a final document. Successes and challenges of the guideline development process were identified and are used to highlight current issues and debates in developing guidelines with a focus on implications for future guideline development at WHO.

The impact of HIV treatment on risk behaviour in developing countries: A systematic review

In developing countries, access to antiretroviral therapy (ART) is improving as HIV treatment becomes a greater priority in the global fight against AIDS. While ART has clearly beneficial clinical effects, increased access to treatment may also affect sexual behaviour. To examine the strength of evidence for the impact of medical treatment for HIV-positive individuals on behavioural outcomes in developing countries, we conducted a comprehensive search of the peer-reviewed literature. Studies were included if they provided clinical treatment to HIV-positive individuals in a developing country, compared behavioural, psychological, social, care, or biological outcomes related to HIV-prevention using a pre/post or multi-arm study design, and were published between January 1990 and January 2006. Only three studies were identified that met the inclusion criteria. All were conducted in Africa, utilized before/after or multi-arm study designs, and relied on self-reported behaviour. In all three studies, a majority of HIV-infected individuals reported being sexually abstinent, and access to ART was not associated with an increase in HIV-related risky sexual behaviours. However, one cross-sectional study found that ART patients were more likely to report STD treatment. The available evidence indicates a significant reduction in risk behaviour associated with ART in developing countries. However, there are few existing studies and the rigor of these studies is weak. More studies are needed to build an evidence base on which to make programmatic and policy decisions.

Biliary hypoplasia in Williams syndrome

Neonatal hepatitis and biliary hypoplasia are not recognised features of Williams syndrome. A case of Williams syndrome, presenting with neonatal conjugated hyperbilirubinaemia leading to an initial misdiagnosis is reported.

Frozen section diagnosis of pancreatic malignancy: a sensitive diagnostic technique

BACKGROUND

Patients with potentially resectable pancreatic masses, without evidence of metastatic disease, require surgical exploration. We assessed the reliability of frozen section diagnosis of pancreatic malignancy.

METHODS

We analysed data from 120 patients who underwent pancreatic exploration, including frozen section assessment, over a period of 41 months.

RESULTS

A total of 310 pancreatic biopsies were sent for frozen section analysis. The frozen section result concurred with the final histological diagnosis in 98.1% of biopsies. The false-negative rate was 1.9%, with the correct diagnosis being established on subsequent frozen section in half of these cases. Only 3 patients were not correctly diagnosed intra-operatively by frozen section. The majority of tumours identified were pancreatic ductal adenocarcinomas, but endocrine tumours and lymphoma were also detected. 15 (12.5%) patients required more than one set of biopsies in order to establish a diagnosis of malignancy. 19 (15.8%) patients had malignant disease outside the pancreas, making their tumours unsuitable for curative resection.

CONCLUSIONS

Frozen section diagnosis is very reliable in the assessment of pancreatic masses and accurately differentiates between benign and malignant disease. More than one biopsy is needed to make a diagnosis, and if clinically suspicious, successive sets of biopsies may be required.

The emergency department versus the computer: which is the better electrocardiographer?

Electrocardiograms (ECGs) are frequently ordered in the pediatric emergency department (ED). Pediatric cardiologists are generally not asked to interpret every ECG; thus, ED patient management is often guided by the ED physicians' ECG interpretation. The objective of this study was to analyze the accuracy of ECG interpretation by ED physicians and a computer-generated interpretation and compare the two. A 12-month prospective study was performed in a pediatric ED. All patients (<22 years) who had an ECG in the ED were included. The ED physicians and the computer interpretation were compared to a reference standard. Each electrocardiographic diagnosis, as well as the ECG as a whole, was assigned to one of the following predetermined classes: I, normal sinus rhythm; II, minimal clinical significance; III, indeterminate clinical significance; IV, those of definite clinical significance. Both groups correctly interpreted all normal (class I) ECGs. The computer correctly interpreted approximately 75% of the class II and class III ECGs, whereas the ED physicians correctly interpreted 36% of both groups. For the class IV ECGs, both the computer and the ED physicians performed poorly, correctly interpreting just 14% and 28%, respectively. The computer proved to be more accurate than the ED physicians in interpreting ECGs of less than critical significance (classes II and III), but neither group was able to correctly interpret even a simple majority of the most significant abnormalities (class IV). We speculate that distributing the computer-generated interpretation to the ED physicians and formal review of all ED ECGs by a skilled interpreter may decrease the number of missed diagnoses.

Role of the glutamate decarboxylase acid resistance system in the survival of Listeria monocytogenes LO28 in low pH foods

The glutamate decarboxylase (GAD) acid resistance system of the foodborne pathogen Listeria monocytogenes plays a major role in its survival at low pH. It was found that survival of the wild-type strain. LO28, in acidified reconstituted skim milk, diluted to reduce free glutamate levels. improves in response to supplementation with monosodium glutamate. A mutant, in which the two listerial GAD homologs have been deleted (and in which there is no discernible GAD activity), did not respond to glutamate supplementation and displayed greatly enhanced sensitivity in a number of low pH foods, even when levels of free glutamate were as low as 0.22 mM. We thus show that the GAD system plays a major role in the survival of L. monocytogenes in acidic foods even when levels of free glutamate are low.

Effectiveness of HIV prevention interventions in developing countries

OBJECTIVE

To review the effectiveness of projects and programs in developing countries that aim to reduce sexual transmission of HIV infection or transmission related to injection drug use.

DESIGN

We identified 34 published studies undertaken in 18 developing countries that met rigorous inclusion criteria. These criteria included the length of follow-up, use of statistical analysis, the inclusion of a comparison group, and type of outcomes measured.

RESULTS

We found that behavioral change interventions are effective when targeted to populations at high risk, particularly female sex workers and their clients. Few studies have evaluated harm reduction interventions in injecting drug users (IDUs). Evidence on the effectiveness of voluntary counseling and testing programs was promising, and VCT was most effective when directed at discordant couples. Treatment of sexually transmitted diseases (STD) appears highly effective in reducing HIV/STD transmission, particularly in the earlier stages of the epidemic.

CONCLUSIONS

This review demonstrates that HIV prevention interventions can be effective in changing risk behaviors and preventing transmission in low and middle-income countries. When the appropriate mix of interventions is applied, they can lead to significant reductions in the prevalence of HIV at the national level. Additional research is needed to identify effective interventions, particularly in men who have sex with men, youth, IDUs and HIV-infected persons. Structural and environmental interventions show great promise, although more evaluation is needed.

Cerebrospinal fluid abnormalities in a phase III trial of Avonex (IFNbeta-1a) for relapsing multiple sclerosis. The Multiple Sclerosis Collaborative Research Group

BACKGROUND AND OBJECTIVE

This report provides results of CSF analyses done in a subset of relapsing remitting MS patients participating in a placebo-controlled, double-blind, phase III clinical trial of IFNbeta-Studies supported by the National Multiple Sclerosis Society (grants RG2019, RG2827),a (Avonex , Biogen). The clinical trial demonstrated that IFNbeta-1a treatment resulted in significantly reduced disability progression, annual relapse rate, and new brain lesions visualized by cranial magnetic resonance imaging. The objectives of the current study were to determine: (a) whether CSF abnormalities in MS patients correlated with disease or MRI characteristics, and (b) effects of IFNbeta-1a therapy on these CSF abnormalities.

METHODS

CSF was analyzed from 262 (87%) of the 301 study subjects at entry into the clinical trial, and a second CSF sample was analyzed from 137 of these 262 subjects after 2 years of therapy. CSF cell counts, oligoclonal bands (OCB), IgG index, and free kappa light chains were measured using standard assays. Baseline CSF results were compared with demographic, disease, and MRI parameters. Differences in on-study relapse rate, gadolinium enhancement, and EDSS change according to baseline CSF status was used to determine the predictive value of CSF for subsequent clinical and MRI disease activity. Change in CSF parameters after 104 weeks were used to determine the effects of treatment.

RESULTS

(1) At study baseline, 37% of the subjects had abnormal CSF WBC counts, 61% had abnormal levels of CSF free kappa light chains, 84% had abnormal IgG index values, and 90% were positive for OCB. (2) Baseline IgG index, kappa light chains, and OCB showed weakly positive, statistically significant correlations with Gd-enhanced lesion volume and T2 lesion volume. WBC showed a statistically significant correlation with Gd-enhancing lesion volume but was uncorrelated with T2 lesion volume. (3) There was an associated between baseline CSF WBC counts and on-study clinical and MRI disease activity in placebo recipients. (4) IFNbeta-1a treatment resulted in significantly reduced CSF WBC counts, but there was no treatment-related change in CSF IgG index, kappa light chains, or OCB, which remained relatively stable over time in both patient groups.

CONCLUSIONS

The current study documents significant reductions in CSF WBC counts in patients treated with IFNbeta-1a for 104 weeks. This finding is considered relevant to the therapeutic response, since CSF WBC counts were found to be positively correlated with subsequent clinical and MRI disease activity in placebo-treated relapsing MS patients.

The ESRC review of government social classifications

In this article we first discuss the background to the ESRC Review of Government Social Classifications and the recommendations of the Review Committee's initial report to the Office for National Statistics in 1995. Second, we discuss the work of Phase 2 of the review, including the derivation of an interim version of a proposed revised government social classification schema and the criterion and construct validation work so far undertaken using this schema. Finally, we indicate the further work required to establish the schema in its ultimate recommended form for use by ONS and others. The main purpose of the paper is to introduce users of government social classifications both to the ideas underlying the review and to the revised version of the current classifications which we shall be recommending to ONS.

Prevention campaigns for hard-to-reach populations at risk for HIV infection: theory and implementation

Using applied behavioral science techniques that have been successful in other areas of health promotion, community-level campaigns were implemented in 5 cities to prevent HIV infection among hard-to-reach, at-risk populations: men who have sex with men but do not self-identify as gay; women who engage in sex for money or drugs; injecting drug users (IDUs), female sex partners of IDUs; and youth in high-risk situations. Communication materials presented positive role models for risk-reducing behaviors, and peer networks prompted and reinforced the behavior change process. This article describes the first year of intervention experience and documents the practical application of theoretical concepts of persuasion and learning. The use of theory and data to develop 188 educational messages is illustrated and training methods and experiences are reported for 150 peer leaders, 104 other community networkers, and 22 outreach workers. These activities are feasible and appear to offer an effective, general approach for diverse, special populations.

Using formative research to lay the foundation for community level HIV prevention efforts: an example from the AIDS Community Demonstration Projects

The AIDS Community Demonstration Projects provided community-level HIV prevention interventions to historically hard-to-reach groups at high risk for HIV infection. The projects operated under a common research protocol which encompassed formative research, intervention delivery, process evaluation, and outcome evaluation. A formative research process specifically focusing on intervention development was devised to assist project staff in identifying, prioritizing, accessing, and understanding the intervention target groups. This process was central to the creation of interventions that were acceptable and unique to the target populations. Intended to be rapid, the process took 6 months to complete. Drawn from the disciplines of anthropology, community psychology, sociology, and public health, the formative research process followed distinct steps which included (a) defining the populations at high-risk for HIV; (b) gathering information about these populations through interviews with persons who were outside of, but who had contact with, the target groups (such as staff from the health department and alcohol and drug treatment facilities, as well as persons who interacted in an informal manner with the target groups, such as clerks in neighborhood grocery stores and bartenders); (c) interviewing people with access to the target populations (gatekeepers), and conducting observations in areas where these high-risk groups were reported to gather (from previous interviews); (d) interviewing members of these groups at high risk for HIV infection or transmission; and (e) systematically integrating information throughout the process. Semistructured interview schedules were used for all data collection in this process. This standardized systematic method yielded valuable information about the focal groups in each demonstration project site. The method, if adopted by others, would assist community intervention specialists in developing interventions that are culturally appropriate and meaningful to their respective target populations.

Comparison of in-hospital mortality from myocardial infarction in the pre- and post-thrombolysis eras at the Royal University Hospital, Saskatoon, Saskatchewan

PURPOSE

To compare in-hospital mortality of acute myocardial infarction (AMI) in two groups of patients in the pre- (1978-79) and post- (1990-91) thrombolysis era via a retrospective study.

DATA SOURCE

Hospital files of patients discharged from the Royal University Hospital (RUH) in Saskatoon, Saskatchewan with the diagnosis of AMI.

RESULTS

The diagnosis of AMI was established in 125 patients in 1978-79 and in 164 patients in 1990-91. The two groups were comparable with exceptions noted in the recorded family history of myocardial infarction and hypercholesterolemia. The overall in-hospital mortality decreased from 21.6% (1978-79) to 11.0% (1990-91; P = 0.05). The difference was more significant for patients admitted directly to the RUH, 24.0% (1978-79) versus 7.0% (1990-91; P = 0.05), and for patients over the age of 70 years. Marked differences were observed in the treatments provided to patients between these two decades.

CONCLUSIONS

The in-hospital mortality of patients with AMI has decreased considerably in the past two decades. The use of thrombolytic agents, acetylsalicylic acid, heparin and beta-blockers may have contributed to these changes. A worse prognosis was observed with advancing age, hypotension on admission and the development of congestive heart failure, malignant arrhythmias or shock.

Racial influence in renal stone disease: a Saskatchewan story

Data was obtained from two separate governement sources in an effort to review the prevalence of kidney stone disease in the province of Saskatchewan for the years 1983-1988 inclusive. The data revealed a statistally significant difference in prevalence rate among different ethnic groups within the population. Aboriginal people were found to have a prevalence rate approximately one-third that of the nonaboriginal (non-native) population. A renal stone episode prevalence of 0.858 per 1000 population compared to 0.222 per 1000 population in aboriginal people (p.<.001). The reasons for this difference could not be retrospectively associated with geographical variation. A discussion of other possible causes in association is offered, but it is felt that, in the end, more research into this area is required.

Risking everything? Risk behavior, behavior change, and AIDS

Inquiry into the determinants of risk-related sexual behavior is important for the development of interventions to reduce the incidence of new cases of human immunodeficiency virus infection. Recent social and behavioral research has revealed much about the individual and social factors influencing risk-taking. Findings from these studies have been important in the development of new educational and community-based interventions for communities at risk in the developed and developing worlds.

Expression of inducible stress protein 70 in rat heart myogenic cells confers protection against simulated ischemia-induced injury

Myocardial ischemia markedly increases the expression of several members of the stress/heat shock protein (HSP) family, especially the inducible HSP70 isoforms. Increased expression of HSP70 has been shown to exert a protective effect against a lethal heat shock. We have examined the possibility of using this resistance to a lethal heat shock as a protective effect against an ischemic-like stress in vitro using a rat embryonic heart-derived cell line H9c2 (2-1). Myogenic cells in which the heat shock proteins have been induced by a previous heat shock are found to become resistant to a subsequent simulated ischemic stress. In addition, to address the question of how much does the presence of the HSP70 contribute to this protective effect, we have generated stably transfected cell lines overexpressing the human-inducible HSP70. Embryonal rat heart-derived H9c2(2-1) cells were used for this purpose. This stably transfected cell line was found to be significantly more resistant to an ischemic-like stress than control myogenic cells only expressing the selectable marker (neomycin) or the parental cell line H9c2(2-1). This finding implicates the inducible HSP70 protein as playing a major role in protecting cardiac cells against ischemic injury.

Calculating receptor number from binding experiments using same compound as radioligand and competitor

Saturation experiments using increasing concentrations of radioligand are commonly used to determine receptor number and affinity, but this protocol is not feasible in all situations. Alternatively, competitive binding experiments are often performed in which binding of a single concentration of radioligand is completed for by multiple concentrations of the same unlabelled ligand, but the analysis of such data has been difficult. Antonio DeBlasi and colleagues present here a simple method for calculating receptor number and affinity from competitive binding data. This experimental protocol is useful when a single class of binding site is present, but is often not able to detect the presence of two classes of site.

Long term survival following bilateral breast angiosarcoma

Angiosarcoma of the breast is a rare and usually rapidly fatal tumour. A 45-year-old woman with bilateral angiosarcoma who has survived 13 years since her original presentation is reported. The management and prognosis of angiosarcomas of the breast is reviewed.

Na+-Ca2+ exchange in cardiac sarcolemma: modulation of Ca2+ affinity by exercise

The high activity of the cardiac Na+-Ca2+ exchanger has led to the suggestion that it plays an important role in the regulation of myocardial contractility. We have proposed that exercise training increases stroke volume as a consequence of an enhanced contractility caused by an adaptation in Ca2+ transport across the cardiac plasma membrane (sarcolemma). The present study examined the possibility that the Na+-Ca2+ exchanger in heart muscle is modified in response to training. Sprague-Dawley rats (female, n = 72) were randomly divided into exercise-trained (T) and sedentary control (C) groups. As a result of the 11-wk treadmill-training paradigm, group T had a 7.6% higher (P less than 0.005) heart-to-body weight ratio and a 36% increase (P less than 0.01) in gastrocnemius mitochondrial enzyme activity. Na+-Ca2+ exchange was studied in highly purified sarcolemmal vesicles using rapid-quenching techniques. The absolute initial rate of uptake was significantly higher in T vs. C at calcium concentrations [( Ca2+]) ranging from 10 to 80 microM. This increased uptake appears to be due solely to the fact that the apparent Km of the myocardial Na+-Ca2+ exchanger for Ca2+ was significantly lower in T vs. C (15.7 +/- 1.1 vs. 36.1 +/- 2.6 microM), since the maximum velocity was unchanged. The observed increase in the affinity of the exchanger for Ca2+ is not attributable to group differences in vesicular purity, cross-contamination, or passive Ca2+ efflux. This observation is consistent with observed alterations in sarcolemmal composition in response to exercise training. We propose that the modification of the Na+-Ca2+ exchanger may play an important role in the adaptation of the heart to exercise.