Accuracy of Online Artificial Intelligence Models in Primary Care Settings

INTRODUCTION

The importance of preventive medicine and primary care in the sphere of public health is expanding, yet a gap exists in the utilization of recommended medical services. As patients increasingly turn to online resources for supplementary advice, the role of artificial intelligence (AI) in providing accurate and reliable information has emerged. The present study aimed to assess ChatGPT-4's and Google Bard's capacity to deliver accurate recommendations in preventive medicine and primary care.

METHODS

Fifty-six questions were formulated and presented to ChatGPT-4 in June 2023 and Google Bard in October 2023, and the responses were independently reviewed by two physicians, with each answer being classified as "accurate," "inaccurate," or "accurate with missing information." Disagreements were resolved by a third physician.

RESULTS

Initial inter-reviewer agreement on grading was substantial (Cohen's Kappa was 0.76, 95%CI [0.61-0.90] for ChatGPT-4 and 0.89, 95%CI [0.79-0.99] for Bard). After reaching a consensus, 28.6% of ChatGPT-4-generated answers were deemed accurate, 28.6% inaccurate, and 42.8% accurate with missing information. In comparison, 53.6% of Bard-generated answers were deemed accurate, 17.8% inaccurate, and 28.6% accurate with missing information. Responses to CDC and immunization-related questions showed notable inaccuracies (80%) in both models.

CONCLUSIONS

ChatGPT-4 and Bard demonstrated potential in offering accurate information in preventive care. It also brought to light the critical need for regular updates, particularly in the rapidly evolving areas of medicine. A significant proportion of the AI models' responses were deemed "accurate with missing information," emphasizing the importance of viewing AI tools as complementary resources when seeking medical information.

Role of aortic valve replacement in moderate aortic stenosis: a 10-year outcomes study

OBJECTIVE

Patients with moderate aortic stenosis (AS) exhibit high morbidity and mortality. Limited evidence exists on the role of aortic valve replacement (AVR) in this patient population. To investigate the benefit of AVR in moderate AS on survival and left ventricular function.

METHODS

In a retrospective cohort study, patients with moderate AS between 2008 and 2016 were selected from the Cleveland Clinic echocardiography database and followed until 2018. Patients were classified as receiving AVR or managed medically (clinical surveillance). All-cause and cardiovascular mortality were assessed by survival analyses. Temporal haemodynamic and structural changes were assessed with longitudinal analyses using linear mixed effects models.

RESULTS

We included 1421 patients (mean age, 75.3±5.4 years and 39.9% women) followed over a median duration of 6 years. Patients in the AVR group had lower risk of all-cause (adjusted HR (aHR)=0.51, 95% CI: 0.34 to 0.77; p=0.001) and cardiovascular mortality (aHR=0.50, 95% CI: 0.31 to 0.80; p=0.004) compared with those in the clinical surveillance group irrespective of sex, receipt of other open-heart surgeries and underlying malignancy. These findings were seen only in those with preserved left ventricular ejection fraction (LVEF) ≥50%. Further, patients in the AVR group had a significant trend towards an increase in LVEF and a decrease in right ventricular systolic pressure compared with those in the clinical surveillance group.

CONCLUSIONS

In patients with moderate AS, AVR was associated with favourable clinical outcomes and left ventricular remodelling.

Utilization and outcome disparities in allogeneic hematopoietic stem cell transplant in the United States

Allogeneic hematopoietic stem cell transplant (allo-HSCT) is increasingly being used in the United States (US) and across the world as a curative therapeutic option for patients with certain high-risk hematologic malignancies and non-malignant diseases. However, racial and ethnic disparities in utilization of the procedure and in outcome following transplant remain major problems. Racial and ethnic minority patients are consistently under-represented in the proportion of patients who undergo allo-HSCT in the US. The transplant outcomes in these patients are also inferior. The interrelated driving forces responsible for the differences in the utilization and transplant outcome of the medical intervention are socioeconomic status, complexity of the procedure, geographical barriers, and the results of differences in the genetics and comorbidities across different races. Bridging the disparity gaps is important not only to provide equity and inclusion in the utilization of this potentially life-saving procedure but also in ensuring that minority groups are well represented for research studies about allo-HSCT. This is required to determine interventions that may be more efficacious in particular racial and ethnic groups. Various strategies at the Federal, State, and Program levels have been designed to bridge the disparity gaps with varying successes. In this review paper, we will examine the disparities and discuss the strategies currently available to address the utilization and outcome gaps between patients of different races in the US.

Incidence, Risk Factors, and Outcomes Associated With Permanent Pacemaker Implantation Following Tricuspid Valve Surgery

BACKGROUND

Data regarding permanent pacemaker (PPM) implantation following tricuspid valve surgery (TVS) are limited. We sought to evaluate its incidence, risk factors, and outcomes.

METHODS AND RESULTS

Medicare beneficiaries who underwent TVS from 2013 to 2020 were identified. Patients who underwent TVS for endocarditis were excluded. The primary exposure of interest was new PPM after TVS. Outcomes included all-cause mortality and readmission with endocarditis or heart failure on follow-up. Among the 13 294 patients who underwent TVS, 2518 (18.9%) required PPM placement. Risk factors included female sex (relative risk [RR], 1.26 [95% CI, 1.17-1.36], P<0.0001), prior sternotomy (RR, 1.12 [95% CI, 1.02-1.23], P=0.02), preoperative second-degree heart block (RR, 2.20 [95% CI, 1.81-2.69], P<0.0001), right bundle-branch block (RR, 1.21 [95% CI, 1.03-1.41], P=0.019), bifascicular block (RR, 1.43 [95% CI, 1.06-1.93], P=0.02), and prior malignancy (RR, 1.23 [95% CI, 1.01-1.49], P=0.04). Tricuspid valve (TV) replacement was associated with a significantly higher risk of PPM implantation when compared with TV repair (RR, 3.20 [95% CI, 2.16-4.75], P<0.0001). After a median follow-up of 3.1 years, mortality was not different in patients who received PPM compared with patients who did not (hazard ratio [HR], 1.02 [95% CI, 0.93-1.12], P=0.7). PPM placement was not associated with a higher risk of endocarditis but was associated with a higher risk of heart failure readmission (HR, 1.28 [95% CI, 1.14-1.43], P<0.001).

CONCLUSIONS

PPM implantation frequently occurs after TVS, notably in female patients and patients undergoing TV replacement. Although mortality is not increased, it is associated with higher rates of heart failure rehospitalization.

Sex Differences in the Progression and Long-Term Outcomes of Native Mild to Moderate Aortic Stenosis

BACKGROUND

There are limited data on the sex differences in the hemodynamic progression and outcomes of early-stage aortic stenosis (AS).

OBJECTIVES

The authors sought to determine sex differences in hemodynamic progression and outcomes of mild to moderate native AS.

METHODS

This was a retrospective observational cohort study including patients with mild to moderate native tricuspid AS from the Cleveland Clinic echocardiographic database between 2008 and 2016 and followed until 2018. All-cause mortality, aortic valve replacement (AVR), and disease progression assessed by annualized changes in echocardiographic parameters were analyzed based on sex.

RESULTS

The authors included 2,549 patients (mean age, 74 ± 7 years and 42.5% women) followed over a median duration of 5.7 years. There was no difference in all-cause mortality between sexes irrespective of age, baseline disease severity, progression to severe AS, and receipt of AVR. Relative to men, women had similar all-cause mortality but lower risk of AVR (adjusted HR: 0.81 [95% CI: 0.67-0.91]; P = 0.009) at 10 years. On 1:1 propensity-matched analysis, men had a significantly faster disease progression represented by greater increases in the median of annualized change in mean gradient (2.10 vs 1.15 mm Hg/y, respectively, P < 0.001), maximum transvalvular velocity (0.42 vs 0.28 m/s/y), left ventricular end-diastolic diameters (0.15 vs 0.048 mm/m2.7/y) (P = 0.014). Women have significantly higher left ventricular ejection fraction, filling pressures, and left ventricular septum thickness over time on follow-up echocardiograms compared with men.

CONCLUSIONS

Women with mild to moderate AS had slower hemodynamic progression of AS, were more likely to have preserved left ventricular ejection fraction and concentric left ventricular hypertrophy in addition to lower incidence of AVR compared with men despite similar mortality. These findings provide further evidence that there are distinct sex-specific longitudinal echocardiographic and clinical profiles in patients with AS.

Multimodality Imaging in the Evaluation and Management of a Right Atrial Mass

•Primary cardiac tumors are mostly cardiac myxomas but rarely present in the RA. •Multimodality imaging can help characterize cardiac masses and guide management. •CMR with a comprehensive protocol provides valuable diagnostic information.

Accuracy of ChatGPT in Common Gastrointestinal Diseases: Impact for Patients and Providers

Since its release in 2022, Chat Generative Pre-Trained Transformer (ChatGPT) became the most rapidly expanding consumer software application in history,1 and its role in medicine is underscored by its potential to enhance patient education and physician-patient communication. Previous studies in gastroenterology and hepatology have focused primarily on the earlier Generative Pre-Trained Transformer 3 (GPT-3) model, with none investigating ChatGPT's ability to generate supportive references for its responses, or its applicability as a physician educational tool.2-6 Our study evaluated the accuracy of the more recent ChatGPT, powered by GPT-4, in addressing frequently asked questions by patients on irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), colonoscopy and colorectal cancer (CRC) screening, questions on CRC screening from a physician perspective, and reference generation and suitability.

Immune checkpoint inhibitors in BRAF-mutated advanced colorectal cancer

Colorectal cancer has been around for a long time, but is still a challenge nonetheless. However, the heterogeneity of the disease opens new potential therapeutic doors. BRAF-mutated advanced colorectal cancer is a demanding entity that does not respond to standard chemotherapy regimens (FOLFOX, capecitabine) and the presence of the mutation significantly weakens the prognosis, but the rise of immunotherapy could reverse the trend. Indeed, pembrolizumab and nivolumab have boasted promising outcomes and increased survival rates among this subset of patients. This article is a collection of these results which could potentially bring immunotherapy to the front line.

Case report: Primary cardiac lymphoma manifesting as superior vena cava syndrome

A 64-year-old man presented with symptoms indicative of superior vena cava syndrome. Imaging work-up revealed an obstructing right atrial mass, which was subsequently excised and diagnosed as primary cardiac lymphoma. Post-surgery, the patient showed significant clinical improvement and was started on a chemotherapy regimen with complete remission at 1 year.

The Added Value of Preprocedural Cardiac Computed Tomography in Planning Left Atrial Appendage Closure With the Watchman FLX Device

•Cardiac computed tomography (CCT) can be used as a useful complementary tool in preprocedural planning of left atrial appendage closure.•CCT planning includes assessing exclusion criteria, device sizing, sheath selection, anticipating challenging anatomies, and transseptal puncture planning.•Procedural 3D intracardiac echocardiography (3D-ICE) is increasingly being used instead of transesophageal echocardiography. In this setting, preprocedural CCT is useful to compensate for 3D ICE's reduced resolution.

Chronic graft-versus-host disease in pediatric patients: Differences and challenges

Despite the use of high-resolution molecular techniques for tissue typing, chronic graft-versus-host disease (cGVHD) remains a major complication following allogeneic hematopoietic stem cell transplant. cGVHD adversely affects the life-expectancy and quality of life. The latter is particularly important and functionally relevant in pediatric patients who have a longer life-expectancy than adults. Current laboratory evidence suggests that there is not any difference in the pathophysiology of cGVHD between adults and pediatric patients. However, there are some clinical features and complications of the disease that are different in pediatric patients. There are also challenges in the development of new therapeutics for this group of patients. In this review, we will discuss the epidemiology, pathophysiology, clinical features and consequences of the disease, and highlight the differences between pediatric and adult patients. We will examine the current treatment options for pediatric patients with moderate to severe cGVHD and discuss the challenges facing therapeutic development for cGVHD in the pediatric population.

Liquid biopsies and minimal residual disease in lymphoid malignancies

Minimal residual disease (MRD) assessment using peripheral blood instead of bone marrow aspirate/biopsy specimen or the biopsy of the cancerous infiltrated by lymphoid malignancies is an emerging technique with enormous interest of research and technological innovation at the current time. In some lymphoid malignancies (particularly ALL), Studies have shown that MRD monitoring of the peripheral blood may be an adequate alternative to frequent BM aspirations. However, additional studies investigating the biology of liquid biopsies in ALL and its potential as an MRD marker in larger patient cohorts in treatment protocols are warranted. Despite the promising data, there are still limitations in liquid biopsies in lymphoid malignancies, such as standardization of the sample collection and processing, determination of timing and duration for liquid biopsy analysis, and definition of the biological characteristics and specificity of the techniques evaluated such as flow cytometry, molecular techniques, and next generation sequencies. The use of liquid biopsy for detection of minimal residual disease in T-cell lymphoma is still experimental but it has made significant progress in multiple myeloma for example. Recent attempt to use artificial intelligence may help simplify the algorithm for testing and may help avoid inter-observer variation and operator dependency in these highly technically demanding testing process.

Splenic Subcapsular Hematoma After Endoscopic Retrograde Cholangiopancreatography

The complications of endoscopic retrograde cholangiopancreatography (ERCP) are numerous and mainly intraluminal. We present a unique case of a patient who developed splenic hematoma after ERCP. A 41-year-old woman was hospitalized for evaluation of chronic abdominal pain, for which she underwent an ERCP. The next day, the patient developed hemorrhagic shock. She was found to have a large ruptured subcapsular splenic bleed. Splenic artery embolization was performed, and the patient was stabilized. In conclusion, a high index of suspicion should be kept when managing patients presenting with unstable vital signs and/or acute anemia after ERCP.

Intestinal barrier functions in hematologic and oncologic diseases

The intestinal barrier is a complex structure that not only regulates the influx of luminal contents into the systemic circulation but is also involved in immune, microbial, and metabolic homeostasis. Evidence implicating disruption in intestinal barrier functions in the development of many systemic diseases, ranging from non-alcoholic steatohepatitis to autism, or systemic complications of intestinal disorders has increased rapidly in recent years, raising the possibility of the intestinal barrier as a potential target for therapeutic intervention to alter the course and mitigate the complications associated with these diseases. In addition to the disease process being associated with a breach in the intestinal barrier functions, patients with hematologic and oncologic diseases are particularly at high risks for the development of increased intestinal permeability, due to the frequent use of broad-spectrum antibiotics and chemoradiation. They also face a distinct challenge of being intermittently severely neutropenic due to treatment of the underlying conditions. In this review, we will discuss how hematologic and oncologic diseases are associated with disruption in the intestinal barrier and highlight the complications associated with an increase in the intestinal permeability. We will explore methods to modulate the complication. To provide a background for our discussion, we will first examine the structure and appraise the methods of evaluation of the intestinal barrier.

Differences in patterns of progression of secondary mitral regurgitation

AIMS

Little data exist about the natural history and disease progression of secondary mitral regurgitation (SMR). We sought to study the temporal progression of left-sided volumes and functions in patients who progress to develop severe SMR.

METHODS AND RESULTS

We screened patients with chronic severe SMR who had at least one previous transthoracic echocardiography showing non-severe MR. Unsupervised phenotypic clustering based on baseline and rate of change in left ventricular (LV) and left atrial (LA) volumes, ejection fraction (EF), and MR severity progression identified two different phenotypes. We then compared them in terms of clinical characteristics, mechanistic and anatomical features, management, and outcomes. A total of 257 patients were included. Cluster 1 started with lower EF and LA strain and higher LV and LA volumes compared with Cluster 2, with a slower progression into severe SMR. At the onset of severe MR, Cluster 2 still had higher EF, lower LV volumes, but similar LA volumes and strain, and less proportionate SMR, compared with Cluster 1. They also had higher tenting height and more compensatory leaflet growth. On follow-up, Cluster 1 had more ventricular-directed therapies, whereas Cluster 2 received more mitral valve interventions. While the heart failure burden was higher in Cluster 1, there was no difference in mortality rates.

CONCLUSION

Based on disease progression, two distinct progression patterns of SMR exist, having different anatomical and mechanistic features with variation in management and outcomes.

Update on immunotherapy in the management of gallbladder cancer

Gallbladder cancer (GBC) is a relatively infrequent but highly lethal cancer with a poor prognosis. Management remains challenging and controversial, and most patients are diagnosed at an advanced stage. However, with the progressive advances in the use of immunotherapies, new treatment modalities are being implemented. In September 2022, the US FDA approved durvalumab (a PD-L1 inhibitor) in combination with chemotherapy for adult patients with locally advanced or metastatic GBC. This groundbreaking news is the first FDA approval for the use of immunotherapy in biliary tract cancers. This article reviews the newest advances and trials regarding immunotherapy for GBC.

Contemporary risk models for infective endocarditis surgery: a narrative review

Infective endocarditis is a complex heterogeneous condition involving the infection of the endocardium and heart valves, leading to severe complications, including death. Surgery is often indicated in patients with infective endocarditis but is associated with elevated risk compared with other forms of cardiac surgery. Risk models play an important role in many cardiac surgeries as they can help inform clinicians and patients regarding procedural risk, decision-making to proceed or not, and influence perioperative management; however, they remain under-utilized in the infective endocarditis settings. Another crucial role of such risk models is to assess predicted versus found mortality, thereby allowing an assessment of institutional performance in infective endocarditis surgery. Traditionally, general cardiac surgery risk models such as European System for Cardiac Operative Risk Evaluation (EuroSCORE), EuroSCORE II, and Society of Thoracic Surgeon's score have been applied to endocarditis surgery. However, there has been the development of many endocarditis surgery-specific scores over the last decade. This review aims to discuss clinical characteristics and applications of all contemporary risk scores in the setting of surgical treatment of infective endocarditis.

Imaging and haemodynamic parameters associated with clinical outcomes following isolated tricuspid valve surgery

INTRODUCTION

Isolated tricuspid valve surgery (TVS) may be associated with high morbidity and mortality. The aim of this study was to investigate the association of preoperative imaging and haemodynamic data derived from echocardiography (ECHO), cardiac magnetic resonance (CMR) and right heart catheterisation (RHC) with postoperative outcomes following TVS.

METHODS

In a retrospective cohort study, patients who underwent isolated TVS at our institution between 2012 and 2020 were screened and followed up to 1 year. We only included those who had all three tests before surgery: ECHO, CMR and RHC. Patients with congenital heart disease, infective endocarditis and those who underwent concomitant valve or pericardial surgery were excluded. The primary outcome was a composite of mortality and congestive heart failure at 1 year. Time-to-event analyses at 1 year and Cox proportional hazards regression analyses were performed.

RESULTS

A total of 60 patients were included (mean age of 60±14 years, 63% women), of whom 67% underwent TV repair. The primary outcome occurred in 16 patients (27%) with a 1-year mortality of 7%. It was associated with ECHO-derived right ventricular (RV) free wall strain and RHC-derived RV systolic and diastolic as well as mean pulmonary pressures. On multivariable Cox regression analysis, only RV systolic and diastolic pressures were significantly associated with the primary outcome at 1 year (HRs=5.9 and 3.4, respectively, p<0.05).

CONCLUSION

Baseline invasive haemodynamic assessment could have a strong association with clinical outcomes and help risk-stratify patients undergoing isolated TVS.

The Lung Microbiota and Lung Cancer: A Growing Relationship

Simple Summary

In the past few years, the microbiota has emerged as a major player in cancer management. The efficacy of chemotherapy or immunotherapy may be influenced by the concomitant use of antibiotics before, during, or shortly after treatment with immune checkpoint inhibitors. Despite this, the mechanism linking the microbiota, host immunity, and malignancies are not clear, and the role of microbiota manipulation and analyses in cancer management is underway. In this manuscript, we discuss the role of the microbiota in the initiation, progression, and treatment outcomes of lung cancer.

Abstract

The lung is home to a dynamic microbial population crucial to modulating immune balance. Interest in the role of the lung microbiota in disease pathogenesis and treatment has exponentially increased. In lung cancer, early studies suggested an important role of dysbiosis in tumor initiation and progression. These results have helped accelerate research into the lung microbiota as a potential diagnostic marker and therapeutic target. Microbiota signatures could represent diagnostic biomarkers of early-stage disease. Lung microbiota research is in its infancy with a limited number of studies and only single-center studies with a significant methodological variation. Large, multicenter longitudinal studies are needed to establish the clinical potential of this exciting field.

Tsunami of immunotherapies in the management of esophageal cancer

Esophageal cancer (EC) is relatively frequent and highly lethal cancer, being the sixth most common cause of cancer death worldwide. The progressive approvals of immunotherapy as first-line and second-line treatment options have paved the way for an evolving new approach to the treatment of this disease. Management of EC is challenging and requires a multimodality approach. Treatment options include surgery, chemoradiotherapy (CRT) and, recently, immunotherapy. The newest guidelines and FDA approvals regarding immunotherapy for EC are reviewed here.

Adhesion molecules in multiple myeloma oncogenesis and targeted therapy

Every day we march closer to finding the cure for multiple myeloma. The myeloma cells inflict their damage through specialized cellular meshwork and cytokines system. Implicit in these interactions are cellular adhesion molecules and their regulators which include but are not limited to integrins and syndecan-1/CD138, immunoglobulin superfamily cell adhesion molecules, such as CD44, cadherins such as N-cadherin, and selectins, such as E-selectin. Several adhesion molecules are respectively involved in myelomagenesis such as in the transition from the precursor disorder monoclonal gammopathy of undetermined significance to indolent asymptomatic multiple myeloma (smoldering myeloma) then to active multiple myeloma or primary plasma cell leukemia, and in the pathological manifestations of multiple myeloma.

Accuracy and predictability of intraocular lens power calculation after photorefractive keratectomy

PURPOSE

To investigate the accuracy and predictability of intraocular lens (IOL) power calculation in postoperative photorefractive keratectomy (PRK) eyes.

SETTING

Gimbel Eye Centre, Calgary, Alberta, Canada.

METHODS

The results in 5 cataract surgery eyes that had had PRK were analyzed retrospectively. Target refractions based on actual and refraction-derived keratometric values were compared with postoperative achieved refractions. The target refractions calculated using 5 IOL formulas and 2 A-constants were also compared with the achieved refractions.

RESULTS

In postoperative PRK eyes, the power calculation was more accurate and predictable when the smaller of either the actual or refraction-derived keratometric value was used to calculate the IOL power. The difference between target and achieved refractions appeared smaller when the Binkhorst formula was used. No significant hyperopic shift was observed after cataract surgery.

CONCLUSION

The smaller of the actual or the refraction-derived keratometric value is recommended for calculating IOL power in post-PRK eyes.

Acute changes in endothelin-1 after hemodialysis for chronic renal failure

Endothelin is a recently described, potent renal vascular and systemic vasoconstrictor peptide. To evaluate the response of this peptide to volume contraction, we measured eight baseline and posthemodialysis samples from seven children, aged 14.5 +/- 3 years, with chronic renal failure. Plasma was extracted and endothelin-1 was measured by radioimmunoassay. Dialysis was performed for a 3- to 3 1/2-hour period, and body weight decreased from 38.0 +/- 14.3 to 36.2 +/- 13.8 kg (p < 0.01) during this time. There were no significant changes in heart rate or respiratory rate after dialysis, but blood pressure fell from 127/80 +/- 22/16 to 114/72 +/- 20/21 mm Hg (p = 0.05 for the systolic pressure). Plasma endothelin-1 concentration increased from 1.5 +/- 1.2 pg/ml at baseline to 7.3 +/- 8.9 pg/ml (p = 0.06) after dialysis; the fall in body weight from dialysis correlated with the increase in endothelin (r = -0.75; p = 0.05). Thus volume contraction from hemodialysis is associated with a rise in plasma endothelin-1, which is related to the acute change in body weight.

Relation of elevated plasma endothelin in congenital heart disease to increased pulmonary blood flow

Endothelin-1 (ET), a potent vasoconstrictor peptide, has been found to be elevated in children with pulmonary hypertension associated with congenital heart defects. To evaluate the effect of pulmonary blood flow on ET concentrations, 5 ml blood samples were obtained peripherally at cardiac catheterization from 35 patients, ages 0.13 to 17 years (median 2). Plasma was extracted and ET measured by radioimmunoassay. Patients were classified into 2 groups based on the presence (group A) or absence (group B) of increased pulmonary blood flow defined as a Qp/Qs > or = 1.5. When the 13 patients (37%) in group A were compared with the 22 patients (63%) in group B there were no significant differences in age, cardiac index, or pulmonary and systemic resistances. ET concentrations were significantly higher in group A patients (median 3.25, range 0 to 16.5 vs median 0, range 0 to 6.35 pg/ml; p < or = 0.05). Pulmonary blood flow and pulmonary artery pressure were also higher in group A patients (p < or = 0.01). When patients within group A were subdivided into those with and without pulmonary hypertension, no difference was present in their ET concentrations (mean/SD: 4.4/4.3 vs 4.0/6.4 pg/ml, p = NS). Thus, ET is elevated in patients with congenital heart disease associated with left-to-right shunts and it appears that this increase is related to increased pulmonary blood flow independent of pulmonary artery pressure.

Extended role of the nurse in ICU

A popular definition of a nurse's extended role is a procedure that is not covered in basic training and for which further training is needed (Rowden, 1987). Nurses' past need for certification and the concept that certain procedures are part of an extended role negates nurses' professionalism. Many nurses fear that the UKCC's abolishment of certification for extended role procedures will open the floodgates for unsafe practice and strip the profession of its protection. This survey analysed what procedures intensive care nurses were performing, how responsibility was related to status, whether certain procedures were classified as extending their role and how staff related these procedures to patient care, staffing levels and professionalism.

Smoking prevalence and attitudes of Gwynedd Health Authority staff towards passive smoking and the Authority's non-smoking policy

In 1989, a postal survey was undertaken to investigate the smoking prevalence and attitudes of Gwynedd Health Authority employees towards the Authority's non-smoking policy, passive smoking and other related issues. The results show a smoking prevalence rate of 22% for those participating in the survey, with over half of all smokers expressing a wish to stop. Although the rate was similar for males and females, it was marginally higher amongst nursing staff and young employees. Smoking prevalence was highest among the ancillary staff, and lowest among the medical and dental professions. Most employees were in broad agreement with the Authority's non-smoking policy, and a majority thought it about right or favoured extending it. Most non-smokers and ex-smokers believed passive smoking to be a health hazard, with an increased number rating it anti-social. Attitudes towards these issues were similar for males and females, with marked differences between the groups employed in different areas of the service. Younger employees were more aware of the dangers of passive smoking, but less sympathetic towards the policy than the older ones. The findings of this study highlight the differences between smokers and non-smokers on all smoking issues. The implications for health education and the Authority's non-smoking policies are discussed.

Chemotactic response of splenic mononuclear cells to angiotensin II in murine schistosomiasis

Murine Schistosomiasis mansoni is a parasitic infection associated with a delayed-type hypersensitivity granulomatous reaction to the schistosome eggs. This reaction is characterized by the accumulation of mononuclear cells and other inflammatory cell types around the eggs. Granuloma macrophages produce angiotensin II (AII), which appears to have immunoregulatory function. By using an in vitro chemotaxis assay, this study demonstrated that AII is a chemotactic factor for splenic mononuclear cells derived from infected mice. The response was bimodal, with peak activities occurring at 10(-10) and 10(-6) M. AII was chemotactic for T lymphocytes, B lymphocytes, and a large population of unidentified mononuclear cells at the optimal chemotactic concentrations of the peptide. At high concentrations, AII was also chemotactic for phagocytic mononuclear cells. Sar1, ala8-AII, an analog of AII with antagonist activity, completely blocked AII-induced chemotaxis. A [3H]-AII binding assay revealed high-affinity specific binding on spleen cells. The binding was rapid, was dependent on radioligand concentration, and was reversible. These latter observations suggest that the chemotactic activity of AII for subpopulations of splenic mononuclear cells is mediated via AII receptors.

Chemotactic response of splenic mononuclear cells to angiotensin II in murine schistosomiasis

Murine Schistosomiasis mansoni is a parasitic infection associated with a delayed-type hypersensitivity granulomatous reaction to the schistosome eggs. This reaction is characterized by the accumulation of mononuclear cells and other inflammatory cell types around the eggs. Granuloma macrophages produce angiotensin II (AII), which appears to have immunoregulatory function. By using an in vitro chemotaxis assay, this study demonstrated that AII is a chemotactic factor for splenic mononuclear cells derived from infected mice. The response was bimodal, with peak activities occurring at 10(-10) and 10(-6) M. AII was chemotactic for T lymphocytes, B lymphocytes, and a large population of unidentified mononuclear cells at the optimal chemotactic concentrations of the peptide. At high concentrations, AII was also chemotactic for phagocytic mononuclear cells. Sar1, ala8-AII, an analog of AII with antagonist activity, completely blocked AII-induced chemotaxis. A [3H]-AII binding assay revealed high-affinity specific binding on spleen cells. The binding was rapid, was dependent on radioligand concentration, and was reversible. These latter observations suggest that the chemotactic activity of AII for subpopulations of splenic mononuclear cells is mediated via AII receptors.