Insights into Acute Pancreatitis Associated COVID-19: Literature Review

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) primarily affects the lungs, causing respiratory symptoms. However, the infection clearly affects all organ systems including the gastrointestinal system. Acute pancreatitis associated with coronavirus disease 2019 (COVID-19) has been widely reported Recent studies have discussed pancreatic compromise incidentally in asymptomatic patients, or in a form of clinical symptoms such as abdominal pain, nausea, or vomiting, which is further reflected in some cases with abnormal serum lipase and amylase levels It was suggested that upregulation of angiotensin-converting enzyme II cell receptors or inflammatory cytokines play a major role in predisposing pancreatic injury in SARS-CoV-2 positive patients To date, there is insufficient data to establish the causality of acute pancreatitis in SARS-CoV-2 infected cases. In this paper, we organize recent studies conducted to observe the frequency of acute pancreatitis associated with COVID-19 cases while highlighting present hypotheses, predisposing factors, and their effect on the outcome, and point to gaps in our knowledge.

Pulseless Electrical Activity: Echocardiographic Explanation of a Perplexing Phenomenon

Pulseless electrical activity (PEA) is considered an enigmatic phenomenon in resuscitation research and practice. Finding individuals with no consciousness or pulse but with continued electrocardiographic (EKG) complexes obviously raises the question of how they got there. The development of monitors that can display the underlying rhythm has allowed us to differentiate between VF, asystole, and PEA. Lack of clear understanding of the emergence of PEA has limited the research and development of interventions that might improve the low rates of survival typically associated with PEA. Over 30 years of studying and practicing resuscitation have allowed the authors to see a substantial rise in PEA with variable survival rates, based on the patients' illness spectrum and intensity of monitoring. This paper presents a small case series of individuals with brain death whose family members consented to the echocardiographic observation of the dying process after disconnection from life support. The observation from these cases confirms that PEA is a late phase in the clinical dying process. Echocardiographic images delineate the stages of pseudo-PEA with ineffective contractions, PEA, and then asystole. The process is contiuous with none of the sudden phase shifts seen in dysrhythmic events such as VF, VT or SVT. The implications of these findings are that PEA is a common manifestation of tissue hypoxia and metabolic substrate depletion. Our findings offer prospects for studies of the development of interventions to improve PEA survival.

Change in Cognitive Function in the Month After Hospitalization for Acute Coronary Syndromes: Findings From TRACE-CORE (Transition, Risks, and Actions in Coronary Events-Center for Outcomes Research and Education)

BACKGROUND

Cognitive function is often impaired during hospitalization, but whether this impairment resolves or persists after discharge is unknown.

METHODS AND RESULTS

We enrolled (April 2011-May 2013) and interviewed during hospitalization and 1-month post-discharge 1521 nondemented acute coronary syndrome survivors enrolled in TRACE (Transitions, Risks and Actions in Coronary Events). Cognitive function was assessed using the Telephone Interview of Cognitive Status (range: 0-41) at both time points. Patients reported demographic and psychosocial characteristics and medical records were abstracted. Using the Telephone Interview of Cognitive Status cut point of ≤28, we defined 4 groups of cognitive change based on cognitive status during hospitalization and 1 month later: consistently impaired, transiently impaired, newly impaired, and consistently nonimpaired. Characteristics associated with cognitive change categories were examined using multinomial logistic regression. Participants were 67% male, 84% non-Hispanic white, with mean age±SD 62±11 years; 16% (n=237) were cognitively impaired during hospitalization, and 11% (n=174) were impaired 1 month after discharge. Overall, 80% were consistently nonimpaired, 9% transiently impaired, 7% consistently impaired, and 4% newly impaired. Lower education level, minority status, low health literacy and numeracy, and higher severity of disease were independently associated with cognitive impairment during and after hospitalization. Male sex was associated with increased risk of cognitive impairment after hospital discharge.

CONCLUSIONS

Cognitive function changes during the transition from hospital to home after acute coronary syndrome are less favorable for men and those with psychosocial vulnerability. Assessing cognitive status both in hospital and post-discharge is important for detecting patients who could benefit from tailored transitional care including early follow-up and booster discharge instructions.

Race and place differences in patients hospitalized with an acute coronary syndrome: Is there double jeopardy? Findings from TRACE-CORE

The objectives of this longitudinal study were to examine differences between whites and blacks, and across two geographical regions, in the socio-demographic, clinical, and psychosocial characteristics, hospital treatment practices, and post-discharge mortality for hospital survivors of an acute coronary syndrome (ACS). In this prospective cohort study, we performed in-person interviews and medical record abstractions for patients discharged from the hospital after an ACS at participating sites in Central Massachusetts and Central Georgia during 2011–2013. Among the 1143 whites in Central Massachusetts, 514 whites in Central Georgia, and 277 blacks in Central Georgia, we observed a gradient of socioeconomic position with whites in Central Massachusetts being the most privileged, followed by whites and then blacks from Central Georgia; similar gradients pertained to psychosocial vulnerability (e.g., 10.7%, 25.1%, and 49.1% had cognitive impairment, respectively) and to the hospital receipt of all 4 evidence-based cardiac medications (35.5%, 18.1%, and 14.4%, respectively) used in the acute management of patients hospitalized with an ACS. Multivariable adjusted odds ratios (95% confidence intervals) for the receipt of a percutaneous coronary intervention for whites and blacks in Georgia vs. whites in Massachusetts were 0.57 (0.46–0.71) and 0.40(0.30–0.52), respectively. Thirty-day and one-year mortality risks exhibited a similar gradient.

The results of this contemporary clinical/epidemiologic study in a diverse patient cohort suggest that racial and geographic disparities continue to exist for patients hospitalized with an ACS.

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We observed a gradient of socio-economic position, treatment practices, and dying.

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Interplay of race and place with treatment practices and post discharge outcomes.

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Racial and geographic disparities continue to exist for patients after an ACS.

Ethical Issues in Registry Research: In-Hospital Resuscitation as a Case Study

Research based on registry studies involves significant ethical issues. Using detailed information about one registry concerning in-hospital resuscitation, we present issues concerning informed consent, access to identifiable medical information, and benefit for participants. In addition, multiple methodological difficulties have indirect implications for the ethical conduct of registry research, including consensus about variable definitions, validity and reliability for clinical decisions, sample sizes, and sources of data. Both direct and indirect ethical issues are examined from the viewpoint of accepted regulations and codes regarding ethical conduct of research; specific examples of more or less ethical solutions to the problems are presented from published research.

Multiple Chronic Conditions and Psychosocial Limitations in Patients Hospitalized with an Acute Coronary Syndrome

BACKGROUND

As adults live longer, multiple chronic conditions have become more prevalent over the past several decades. We describe the prevalence of, and patient characteristics associated with, cardiac- and non-cardiac-related multimorbidities in patients discharged from the hospital after an acute coronary syndrome.

METHODS

We studied 2174 patients discharged from the hospital after an acute coronary syndrome at 6 medical centers in Massachusetts and Georgia between April 2011 and May 2013. Hospital medical records yielded clinical information including presence of eight cardiac-related and eight non-cardiac-related morbidities on admission. We assessed multiple psychosocial characteristics during the index hospitalization using standardized in-person instruments.

RESULTS

The mean age of the study sample was 61 years, 67% were men, and 81% were non-Hispanic whites. The most common cardiac-related morbidities were hypertension, hyperlipidemia, and diabetes (76%, 69%, and 31%, respectively). Arthritis, chronic pulmonary disease, and depression (20%, 18%, and 13%, respectively) were the most common noncardiac morbidities. Patients with ≥4 morbidities (37% of the population) were slightly older and more frequently female than those with 0-1 morbidity; they were also heavier and more likely to be cognitively impaired (26% vs 12%), have symptoms of moderate/severe depression (31% vs 15%), high perceived stress (48% vs 32%), a limited social network (22% vs 15%), low health literacy (42% vs 31%), and low health numeracy (54% vs 42%).

CONCLUSION

Multimorbidity, highly prevalent in patients hospitalized with an acute coronary syndrome, is strongly associated with indices of psychosocial deprivation. This emphasizes the challenge of caring for these patients, which extends well beyond acute coronary syndrome management.

Reliability of Predicting Early Hospital Readmission After Discharge for an Acute Coronary Syndrome Using Claims-Based Data

Early rehospitalization after discharge for an acute coronary syndrome, including acute myocardial infarction (AMI), is generally considered undesirable. The Centers for Medicare and Medicaid Services (CMS) base hospital financial incentives on risk-adjusted readmission rates after AMI, using claims data in its adjustment models. Little is known about the contribution to readmission risk of factors not captured by claims. For 804 consecutive patients >65 years discharged in 2011 to 2013 from 6 hospitals in Massachusetts and Georgia after an acute coronary syndrome, we compared a CMS-like readmission prediction model with an enhanced model incorporating additional clinical, psychosocial, and sociodemographic characteristics, after principal components analysis. Mean age was 73 years, 38% were women, 25% college educated, and 32% had a previous AMI; all-cause rehospitalization occurred within 30 days for 13%. In the enhanced model, previous coronary intervention (odds ratio [OR] = 2.05, 95% confidence interval [CI] 1.34 to 3.16; chronic kidney disease OR 1.89, 95% CI 1.15 to 3.10; low health literacy OR 1.75, 95% CI 1.14 to 2.69), lower serum sodium levels, and current nonsmoker status were positively associated with readmission. The discriminative ability of the enhanced versus the claims-based model was higher without evidence of overfitting. For example, for patients in the highest deciles of readmission likelihood, observed readmissions occurred in 24% for the claims-based model and 33% for the enhanced model. In conclusion, readmission may be influenced by measurable factors not in CMS' claims-based models and not controllable by hospitals. Incorporating additional factors into risk-adjusted readmission models may improve their accuracy and validity for use as indicators of hospital quality.

Characteristics of contemporary patients discharged from the hospital after an acute coronary syndrome

BACKGROUND

Limited contemporary data compare the clinical and psychosocial characteristics and acute management of patients hospitalized with an initial vs a recurrent episode of acute coronary disease. We describe these factors in a cohort of patients recruited from 6 hospitals in Massachusetts and Georgia after an acute coronary syndrome.

MATERIALS AND METHODS

We performed structured baseline in-person interviews and medical record abstractions for 2174 eligible and consenting patients surviving hospitalization for an acute coronary syndrome between April 2011 and May 2013.

RESULTS

The average patient age was 61 years, 64% were men, and 47% had a high school education or less; 29% had a low general quality of life, and 1 in 5 were cognitively impaired. Patients with a recurrent coronary episode had a greater burden of previously diagnosed comorbidities. Overall, psychosocial burden was high, and more so in those with a recurrent vs those with an initial episode. Patients with an initial coronary episode were as likely to have been treated with all 4 effective cardiac medications (51.6%) as patients with a recurrent episode (52.3%), but were significantly more likely to have undergone cardiac catheterization (97.9% vs 92.9%) and a percutaneous coronary intervention (73.7% vs 60.9%) (P < .001) during their index hospitalization.

CONCLUSIONS

Patients with a first episode of acute coronary artery disease have a more favorable psychosocial profile, less comorbidity, and receive more invasive procedures but similar medical management, than patients with previously diagnosed coronary disease. Implications of the high psychosocial burden on various patient-related outcomes require investigation.

Primary care residents lack comfort and experience with alcohol screening and brief intervention: a multi-site survey

BACKGROUND

Approximately one in six adults in the United States (U.S.) binge drinks. The U.S. Preventive Services Task Force recommends that primary care physicians screen patients for such hazardous alcohol use, and when warranted, deliver a brief intervention.

OBJECTIVE

We aimed to determine primary care residents' current practices, perceived barriers and confidence with conducting alcohol screening and brief interventions (SBI).

DESIGN

This was a multi-site, cross-sectional survey conducted from March 2010 through December 2012.

PARTICIPANTS

We invited all residents in six primary care residency programs (three internal medicine programs and three family medicine programs) to participate. Of 244 residents, 210 completed the survey (response rate 86 %).

MAIN MEASURES

Our survey assessed residents' alcohol screening practices (instruments used and frequency of screening), perceived barriers to discussing alcohol, brief intervention content, and self-rated ability to help hazardous drinkers. To determine the quality of brief interventions delivered, we examined how often residents reported including the three key recommended elements of feedback, advice, and goal-setting.

KEY RESULTS

Most residents (60 %, 125/208) reported "usually" or "always" screening patients for alcohol misuse at the initial clinic visit, but few residents routinely screened patients at subsequent acute-care (17 %, 35/208) or chronic-care visits (33 %, 68/208). Only 19 % (39/210) of residents used screening instruments capable of detecting binge drinking. The most frequently reported barrier to SBI was lack of adequate training (54 %, 108/202), and only 21 % (43/208) of residents felt confident they could help at -risk drinkers. When residents did perform a brief intervention, only 24 % (49/208) "usually" or "always" included the three recommended elements.

CONCLUSIONS

A minority of residents in this multi-site study appropriately screen or intervene with at-risk alcohol users. To equip residents to effectively address hazardous alcohol use, there is a critical need for educational and clinic interventions to support alcohol-related SBI.

Abstract 159: Medication Adherence Improves Shortly After Acute Coronary Syndrome Admission and Then Declines Over One Year: Findings from TRACE-CORE

Background: Incomplete medication adherence is common, results in poor outcomes, and remains resistant to change in patients with acute coronary syndromes (ACS). However, few studies, if any, have reported patterns of adherence at multiple time points during patients’ transition from the hospital to their community.

Objective: To describe patterns of self-reported medication adherence at admission and over a post-discharge transitional period of 12 months.

Methods: Adult patients (n=2187) hospitalized for ACS enrolled in the “Transitions, Risks, and Actions in Coronary Events Center for Outcomes Research and Education” (TRACE-CORE) cohort from GA and MA completed the 8-item Morisky Medication Adherence Scale (range: 0-8) in person during hospitalization and via telephone interviews at 1-, 3-, 6-, and 12- month(s) after discharge. High, medium, and low adherence were defined as scale scores of 8, 6-7 and 0-5, respectively and analyzed. Repeated measures ANOVA was used to test for differences in mean adherence across the assessment periods.

Results: Participants were 66% male, 16% non-Hispanic black, 81% non-Hispanic white, and aged 61.3 ± 11.34 years. High adherence was reported by 25% at baseline, increased to 50.9% at 1-month, and subsequently dropped to 46%, 45%, and 44% by 3,6, and 12 months, respectively (table). Mean adherence scores (n=906) increased from 6.15(SD=1.78) at baseline to 7.05 (1.23) at 1-month then slightly decreased and leveled off [6.95(1.31), 6.93(1.31), 6.89(1.36); p<0.001 for changes over time]. Baseline differed from all other scores and 1-month scores differed from baseline, 6-, and 12-months.

Conclusion: A major increase in high adherence from baseline to 1-month was followed by a slight decline from 3 to 12 months post discharge. The improvement in adherence from baseline may have been prompted by the “teachable moment” resulting from an ACS. Further research may delineate interventional factors during this transition period that may improve long-term adherence.

Abstract 126: In-hospital Depression Predicts Early Hospital Readmission after an Acute Coronary Syndrome: Preliminary Data from TRACE-CORE

Background: Hospital systems, patients and providers seek to avert rehospitalizations within 30 days for patients admitted with an acute coronary syndrome (ACS). Rehospitalizations within 30 days of discharge are often considered preventable and to reflect poor in-hospital management or discharge practices. However, independent associations of psychosocial factors with early rehospitalization in patients admitted with an ACS have not been examined.

Methods: A multi-racial cohort of 1,540 patients admitted with an ACS reported psychosocial factors via standardized questionnaires in an in-hospital interview. One month following discharge, patients were interviewed via phone and reported hospital readmissions. We used logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of the association between in-hospital psychosocial characteristics (depression, anxiety, and perceived stress), health literacy and numeracy, and cognitive status, with self-reported readmission within 30 days.

Results: Participants were 34% female and 17% non-white, with a mean age of 62 years and a mean length of stay of 4.1 days. Rehospitalization was reported for 14% (n=208) of participants, 77% of which were due to CVD. In univariate analyses, in-hospital severe depression, anxiety, and high stress were associated with higher odds of early readmission, whereas low health numeracy was associated with lower odds of early readmission (Table 1). Severe depression remained associated with higher odds and low health numeracy remained associated with lower odds of early readmission in a multivariable model including covariates associated on univariate testing with rehospitalization.

Conclusions: Early readmission after hospitalization for an ACS was common and associated with in-hospital depression and health numeracy. Notably, depression and health numeracy were the only predictors independently associated with readmission in multivariable analyses. We speculate that the lower likelihood of readmission for those with low numeracy may be related to less engagement with the healthcare system. In-hospital screening for depression and characterization of health numeracy may help stratify risk for early rehospitalization after an ACS.

Long-term follow-up of participants with heart failure in the antihypertensive and lipid-lowering treatment to prevent heart attack trial (ALLHAT)

BACKGROUND

In the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), a randomized, double-blind, practice-based, active-control, comparative effectiveness trial in high-risk hypertensive participants, risk of new-onset heart failure (HF) was higher in the amlodipine (2.5-10 mg/d) and lisinopril (10-40 mg/d) arms compared with the chlorthalidone (12.5-25 mg/d) arm. Similar to other studies, mortality rates following new-onset HF were very high (≥50% at 5 years), and were similar across randomized treatment arms. After the randomized phase of the trial ended in 2002, outcomes were determined from administrative databases.

METHODS AND RESULTS

With the use of national databases, posttrial follow-up mortality through 2006 was obtained on participants who developed new-onset HF during the randomized (in-trial) phase of ALLHAT. Mean follow-up for the entire period was 8.9 years. Of 1761 participants with incident HF in-trial, 1348 died. Post-HF all-cause mortality was similar across treatment groups, with adjusted hazard ratios (95% confidence intervals) of 0.95 (0.81-1.12) and 1.05 (0.89-1.25), respectively, for amlodipine and lisinopril compared with chlorthalidone, and 10-year adjusted rates of 86%, 87%, and 83%, respectively. All-cause mortality rates were also similar among those with reduced ejection fractions (84%) and preserved ejection fractions (81%), with no significant differences by randomized treatment arm.

CONCLUSIONS

Once HF develops, risk of death is high and consistent across randomized treatment groups. Measures to prevent the development of HF, especially blood pressure control, must be a priority if mortality associated with the development of HF is to be addressed. Clinical Trial Registration- http://www.clinicaltrials.gov. Unique identifier: NCT00000542.

Health-behavior induced disease: return of the milk-alkali syndrome

The milk-alkali syndrome is a well-documented consequence of excessive calcium and alkali intake first recognized in association with early 20th century antacid regimens. The syndrome became rare after widespread implementation of modern peptic ulcer disease therapies. With recent trends in osteoporosis therapy coupled with widely available calcium-containing supplements, the milk-alkali syndrome has reemerged as an important clinical entity. Our case illustrates a patient who self-medicated his peptic ulcer disease with a regimen resembling a common early 20th century dyspepsia regimen. When superimposed upon chronic high calcium supplementation, the patient became acutely ill from the milk-alkali syndrome. When taken to excess, or used inappropriately, medications and supplements ordinarily considered beneficial, can have harmful effects. Our case underscores the importance of obtaining a thorough medication history including use of over-the-counter supplementation.

Cytokines in human breast cyst fluid

Gross cystic breast disease is a common benign disorder in which palpable cysts occur in the breast and are normally treated by aspiration of the contents. The cysts are classified as either Type 1, containing a high level of potassium ions and a low level of sodium ions, or as Type 2, with low potassium and high sodium ion concentrations. Steroid sulphatase activity in MDA-MB-231 and MCF-7 cell lines is regulated by exogenous breast cyst fluid (BCF), possibly because of cytokines in the BCF. A screening method was used to determine the range of cytokines in eight BCFs, four of each type. This was an array system, which uses antibodies immobilised on a membrane to qualitatively detect 79 different cytokines or growth factors. Nine cytokines were detected well above background levels: all were found in both types of BCF, but only epidermal growth factor (EGF) was higher in Type 1. All the other factors were higher in Type 2 BCF. Two of these cytokines, IL-6 and EGF, have previously been suggested to affect steroid sulphatase expression and several (MIP-1beta, IL-8, NAP-2) are known to affect MCF-7 cell chemotaxis. In addition two cytokines were measured by ELISA in 57 BCFs, and both IL-1beta and IL-13 were found in BCF, with significantly higher amounts of IL-1beta in Type 1 than Type 2 BCF (35.5+/-4.4 pg/ml versus 9.9+/-2.9 pg/ml).

Academic competencies for medical faculty

INTRODUCTION

Physicians and basic scientists join medical school faculties after years of education. These individuals are then required to function in roles for which they have had little preparation. While competencies needed to perform in medical school, residency, and practice are defined, there is little guidance for faculty.

METHODS

An expert advisory group of the Faculty Futures Initiative developed a document delineating competencies required for successful medical faculty. The proportion of time faculty in various roles should allocate to activities related to each competency was also identified. Competencies and time allocations were developed for various teacher/administrators, teacher/educators, teacher/researchers, and teacher/clinicians. This work was validated by multiple reviews by an external panel.

RESULTS

Trial implementation of the products has occurred in faculty development programs at four medical schools to guide in planning, career guidance, and evaluations of faculty fellows.

DISCUSSION

The competencies and time allocations presented here help faculty and institutions define skills needed for particular faculty roles, plan for faculty evaluation, mentoring and advancement, and design faculty development programs based on identified needs.

Resuscitation in the hospital: circadian variation of cardiopulmonary arrest

PURPOSE

Over 25 reports have found outpatient frequency of sudden cardiac death peaks between 6 am and noon; few studies, with inconsistent results, have examined circadian variation of death in hospitalized patients. This study assesses circadian variation in cardiopulmonary arrest of in-hospital patients across patient, hospital, and event variables and its effect on survival to discharge.

METHODS

A retrospective, single institution registry included all admissions to the Medical Center of Central Georgia in which resuscitation was attempted between January 1987 and December 2000. The registry included 4692 admissions; only the first attempt was reported. Analyses of 1-, 2-, 4-, and 8-hour intervals were performed; 1- and 4-hour intervals are presented.

RESULTS

Significant circadian variation was found at 1 hour (P=.01), but not at 4-hour intervals. Significant circadian variation was found for initial rhythms that were perfusing (P=.03) and asystole (P=.01). A significantly higher percentage of unwitnessed events were found as asystole during the overnight hours (P=.002). Using simple logistic regression, time in 4-hour intervals and rhythm were each significantly related to patient survival until hospital discharge (P=.003 and P <.0001). In multivariate analysis, only rhythm remained significant.

CONCLUSIONS

Circadian variation of cardiopulmonary arrest in this hospital has several temporal versions and is related to survival. Late night variation in witnessed events and rhythm suggests a delay between onset of clinical death and discovery, which contributes to poorer outcomes.

Interobservational variation in determining fusion rates in anterior cervical discectomy and fusion procedures

The fusion rate represents one of the most commonly used criteria for evaluating the efficacy of spinal surgical techniques and the effectiveness of newly developed instrumentation and spinal implants. Reported fusion rates are not frequently supported by adequate information regarding by whom and how fusion was defined. In our prospective study we examined the fusion rate in patients undergoing first time anterior cervical discectomy and fusion for degenerative disease. Separate, well-defined radiographic fusion criteria were used and the 12-month post-operative X-rays were reviewed independently by a neurosurgeon, a neuroradiologist and an orthopedic surgeon, who were not involved in the patients' management. The observed fusion rates were 77.3, 87.8 and 84.7% respectively. Statistical analysis demonstrated concordance rates of 87.8, 91 and 91.4% and Kappa coefficients of 0.585, 0.620 and 0.723 for each pair of evaluators. Another set of ratings of the same radiographs, by the same interviewers, was obtained 6 weeks after the initial one. The reported fusion rates were 78.2% for the neurosurgeon, 87.4% for the orthopedic surgeon, and 86.1% for the neuroradiologist. Statistical analysis demonstrated intra-observer concordance rates of 98.7, 92.2 and 97.9% respectively, while the Kappa coefficients were 0.963, 0.677 and 0.907 for each reviewer. Our findings confirm the necessity of defining and describing criteria for fusion whenever this rate is reported in clinical series. The lack of widely accepted, well-defined criteria makes comparison of these results difficult. The development of a well organized, prospective clinical study in which fusion and outcome will be assessed by both clinical and radiographic parameters could significantly contribute to a more accurate evaluation of overall outcome of cervical spinal procedures.

Clinical outcomes in antihypertensive treatment of type 2 diabetes, impaired fasting glucose concentration, and normoglycemia: Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

BACKGROUND

Optimal first-step antihypertensive drug therapy in type 2 diabetes mellitus (DM) or impaired fasting glucose levels (IFG) is uncertain. We wished to determine whether treatment with a calcium channel blocker or an angiotensin-converting enzyme inhibitor decreases clinical complications compared with treatment with a thiazide-type diuretic in DM, IFG, and normoglycemia (NG).

METHODS

Active-controlled trial in 31 512 adults, 55 years or older, with hypertension and at least 1 other risk factor for coronary heart disease, stratified into DM (n = 13 101), IFG (n = 1399), and NG (n = 17 012) groups on the basis of national guidelines. Participants were randomly assigned to double-blind first-step treatment with chlorthalidone, 12.5 to 25 mg/d, amlodipine besylate, 2.5 to 10 mg/d, or lisinopril, 10 to 40 mg/d. We conducted an intention-to-treat analysis of fatal coronary heart disease or nonfatal myocardial infarction (primary outcome), total mortality, and other clinical complications.

RESULTS

There was no significant difference in relative risk (RR) for the primary outcome in DM or NG participants assigned to amlodipine or lisinopril vs chlorthalidone or in IFG participants assigned to lisinopril vs chlorthalidone. A significantly higher RR (95% confidence interval) was noted for the primary outcome in IFG participants assigned to amlodipine vs chlorthalidone (1.73 [1.10-2.72]). Stroke was more common in NG participants assigned to lisinopril vs chlorthalidone (1.31 [1.10-1.57]). Heart failure was more common in DM and NG participants assigned to amlodipine (1.39 [1.22-1.59] and 1.30 [1.12-1.51], respectively) or lisinopril (1.15 [1.00-1.32] and 1.19 [1.02-1.39], respectively) vs chlorthalidone.

CONCLUSION

Our results provide no evidence of superiority for treatment with calcium channel blockers or angiotensin-converting enzyme inhibitors compared with a thiazide-type diuretic during first-step antihypertensive therapy in DM, IFG, or NG.

Cardiopulmonary assessment: is improvement needed?

Clinical parameters alone have repeatedly been proven unreliable in assessing cardiopulmonary status, especially in hemodynamically unstable patients. To learn if we had a diagnostic problem in our hospital, we compared physician assessment of cardiac index (CI) and thoracic fluid content (TFC) to values obtained using impedance cardiography (ICG). We selected the newest available ICG monitor, the BioZ, which employs this noninvasive technology. For CI measurements we have shown it to be equivalent to thermodilution and to be more reproducible (variability: 6.3% vs. 24.7%). Physician assessment of CI and TFC (high, normal, or low) was compared to the BioZ monitor's results in 186 patients, considered to be hemodynamically unstable, from the emergency room, the intensive care units, and the floors. Normal values were defined for CI (2.5-4.2 L/min m(2)) and for TFC (males: 30-50 kohm(-1) and females: 21-37 kohm(-1)). The concordance between physician assessment and the BioZ was 51% for CI with Kappa of 0.14 and 58% for TFC with Kappa of 0.19. Attendings did slightly better than the surgical residents with CI (52% vs. 48%) but slightly worse with TFC (57% vs. 61%). The potentially serious conditions of low CI and high TFC were misdiagnosed 42% and 46% of the time, respectively, by all physicians. Analysis of the data revealed that physician use of clinically available objective hemodynamic data, such as heart rate, blood pressure, and pulse pressure index, would not have been helpful. Furthermore, assistance from the pulmonary artery catheter (PAC) is often not available in our hospital, which has experienced a 90% decrease in its utilization over the past six years. Considering the increasing acuity of our aging patient population, accurate assessment of cardiopulmonary status is needed. The use of ICG could be a valuable addition to the physician's armamentarium.

Pharmacokinetics of the nonsteroidal steroid sulphatase inhibitor 667 COUMATE and its sequestration into red blood cells in rats

Breast cancer is a major cause of mortality in Western countries and there is an urgent requirement for novel treatment strategies. The nonsteroidal sulphatase inhibitor 667 COUMATE inhibits hepatic steroid sulphatase and growth of oestrone sulphate stimulated tumours in the nitrosomethylurea-induced rat mammary model. Other compounds that contain an aryl sulphamate moiety, for example, oestrone-3-O-sulphamate, are sequestered into red blood cells (RBCs). The aims of this study were to determine the pharmacokinetics of 667 COUMATE and to investigate its sequestration into RBCs. We administered a single p.o. or i.v. dose (10 mg kg⁻¹) of 667 COUMATE to rats and used a high-performance liquid chromatography method to measure the levels of the agent and its putative metabolites in plasma. 667 COUMATE had a bioavailability of 95% and could be detected in plasma for up to 8 h. Using two independent analytical methods, we demonstrated that 667 COUMATE is sequestered by RBCs both ex vivo and in vivo. Previous investigations have revealed that 667 COUMATE is rapidly degraded in plasma ex vivo. In this study, we demonstrate that 667 COUMATE is stabilised due to its sequestration into RBCs. In conclusion, the pharmacological efficacy and high oral bioavailability of 667 COUMATE may be partly a consequence of the ability of RBCs to both protect the agent from metabolic degradation and facilitate its transport to tissues. These data support the further clinical evaluation of this novel endocrine therapeutic agent.

Abdominal adiposity in U.S. adults: prevalence and trends, 1960-2000

BACKGROUND

There is a large body of epidemiologic evidence linking abdominal obesity to cardiovascular diseases. Abdominal adiposity is an important component of insulin resistance syndrome.

OBJECTIVE

To investigate prevalence and trends in abdominal obesity in U.S. adult population. DESIGN, SETTING/PARTICIPANTS: Nationally representative cross-sectional surveys with an in-person interview and measurement of waist circumference; 23,654 adults aged 20-79 years were examined using data from U.S. National Surveys of 1960-1962 [the first National Health Examination Survey (NHES I)], 1988-1994 [the third National Health and Nutrition Examination Survey (NHANES III)] and 1999-2000 [National Health and Nutrition Examination Survey (NHANES 1999-2000)]. Abdominal obesity was defined as waist circumference > or = 102 cm (>40 in.) in men and > or = 88 cm (>35 in.) in women.

RESULTS

There was a gradient of increasing waist circumference over the three periods of 1960-1962, 1988-1994 and 1999-2000 in both men and women. In men, the mean waist circumferences were 89, 95 and 99 cm for 1960-1962, 1988-1994 and 1999-2000, respectively. The corresponding values in women were 77, 92 and 94 cm, respectively. A gradient of increasing prevalence of abdominal obesity from 1960 to 2000 was also observed in men and women. In men, the overall age-adjusted prevalences of abdominal obesity were 12.7%, 29% and 38.3% in 1960-1962, 1988-1994 and 1999-2000, respectively. In women, the analogous values were 19.4%, 38.8% and 59.9%, respectively. Similar trends of increasing waist circumference and abdominal obesity were observed in normal weight, underweight and obese subjects defined using body mass index (BMI). Trends of increasing abdominal obesity with increasing BMI over the three time periods were also observed.

CONCLUSIONS

The increase in the prevalence of abdominal obesity in the United States between 1960-1962 and 1999-2000 has ominous public health implications across entire population, particularly among normal weight subjects. There is an urgent need to describe a public health strategy for early identification of abdominal obesity. Primary prevention of obesity, including abdominal obesity, should be a major public health priority in the United States.

Trends of abdominal adiposity in white, black, and Mexican-American adults, 1988 to 2000

OBJECTIVE

To describe changes in the distribution of waist circumference (WC) and abdominal obesity (AO) in white, black, and Mexican-American adults from 1988 through 2000.

RESEARCH METHODS AND PROCEDURES

Nationally representative cross-sectional surveys of adults 20 to 79 years of age were examined using data from U.S. National Health and Nutrition Examination Surveys of 1988 to 1994 and 1999 to 2000. AO was defined as WC > or =102 cm in men and > or 88 cm in women.

RESULTS

There was a gradient of increasing WC and AO with increasing age in both study periods in whites and blacks. In men, the average increase between the study periods in overall WC in whites, blacks, and Mexican Americans were 3, 3.3, and 3.4 cm, respectively. The corresponding values in women were 2.4, 5.3, and 3.7 cm, respectively. In men, the percentage change in prevalence of AO between 1988 and 2000 ranged from 5.5% in Mexican-American men to 8.2% in white men. In women, there was a 1.7% decrease in AO in Mexican Americans, whereas there was an increase of 6.3% for whites and 7% for blacks.

DISCUSSION

Despite increased understanding of the need for screening and treatment for obesity, this study indicates increasing prevalence of AO in white and black Americans. Without concerted effort to reduce the prevalence of overall obesity, the increasing prevalence of AO is likely to lead to increased prevalence of metabolic syndromes in the United States. Our results highlight the need to design evidence-based programs that show promise for long-term health behavior changes to facilitate the prevention of AO and related comorbidities.

Success changes the problem: why ventricular fibrillation is declining, why pulseless electrical activity is emerging, and what to do about it

BACKGROUND

Programs for research and practice in resuscitation have focused on identification and reversal of ventricular fibrillation (VF). While substantial progress has been achieved, evidence is accumulating that clinical death is less likely to be caused by fibrillation now than in the 1960s and 1970s. Pulseless electrical activity (PEA) has emerged as the most common rhythm found in arrests in the hospital and is rapidly rising in pre-hospital reports.

PURPOSE

To identify the magnitude of changes occurring, search for potential explanations from population and clinical epidemiology and present the data available regarding etiology and treatment of PEA.

DATA SOURCES

Synthesis of material from population epidemiology, clinical epidemiology, animal and human research on VF and PEA.

CONCLUSIONS

VF is a manifestation of severe, undiagnosed coronary artery disease (CAD). Rates of death from CAD increased from rare in 1930 to become the most common cause of death in the US. CAD death rates peaked in the early 1960s and had declined over 50% by the late 1990s. Primary and secondary prevention, early diagnosis and aggressive, successful treatment have contributed to this decline. PEA is a brief phase in clinical death that occurs after losses in consciousness, ventilatory drive and circulation but before decay to asystole; survival rates are poor. PEA is a common stage in clinical death from any of a variety of tissue hypoxic/anoxic insults. Research on PEA is needed; 50 years of attention to CAD and VF have resulted in improved survival and changed the disease spectrum. Similar attention to animal and clinical research on PEA may have the potential to improve survival.

Medical students' attitudes in a PBL curriculum: trust, altruism, and cynicism

PURPOSE

Studies have shown that medical students become more cynical and less altruistic as they advance in training. However, these studies were conducted in traditional medical schools, and many used unvalidated tools. This study examined students' attitudes in a problem-based learning (PBL) curriculum using reliable and valid measures.

METHOD

Medical students and PGY-1 residents at Mercer University School of Medicine in Macon, Georgia, completed Wrightsman's Philosophies of Human Natures Scale (PHNS) in 1999 and 2000. Chronbach's alpha assessed internal reliability among subscales, and test-retest reliability coefficients confirmed acceptable reliability. For 114 students who completed both surveys, changes in PHNS scores were analyzed, with particular attention to the subscales of trustworthiness, altruism, and cynicism.

RESULTS

Students assessed at the beginning of their second year increased the extent to which they believed people are trustworthy and increased their beliefs in how altruistic people are. They also showed a significant decrease in cynicism. There was not a significant change in trustworthiness, altruism, or cynicism among the participants beyond first year. In general, female students held less cynical views about others and believed people to be more trustworthy.

CONCLUSIONS

Contrary to prior reports, this study found that more advanced trainees were not more cynical or less altruistic than their more junior counterparts. Indeed, a significant and positive change of attitudes among the participants during their first year of medical school refuted earlier reports. Thus, results of earlier studies and the effect of a PBL curriculum on attitudes of medical students need to be re-examined.

Validation of a clinical decision aid to discontinue in-hospital cardiac arrest resuscitations

CONTEXT

Most patients undergoing in-hospital cardiac resuscitation do not survive to hospital discharge. In a previous study, we developed a clinical decision aid for identifying all patients undergoing resuscitation who survived to hospital discharge.

OBJECTIVE

To validate our previously derived clinical decision aid.

DESIGN, SETTING, AND PARTICIPANTS

Data from a large registry of in-hospital resuscitations at a community teaching hospital in Georgia were analyzed to determine whether patients would be predicted to survive to hospital discharge (ie, whether their arrest was witnessed or their initial cardiac rhythm was either ventricular tachycardia or ventricular fibrillation or they regained a pulse during the first 10 minutes of chest compressions). Data from 2181 in-hospital cardiac resuscitation attempts in 1987-1996 involving 1884 pulseless patients were analyzed.

MAIN OUTCOME MEASURE

Comparison of predictions based on the decision aid with whether patients were actually discharged alive from the hospital.

RESULTS

For 327 resuscitations (15.0%), the patient survived to hospital discharge. For 324 of these resuscitations, the patients were predicted to survive to hospital discharge (sensitivity = 99.1%, 95% confidence interval, 97.1%-99.8%). In 269 resuscitations, patients did not satisfy the decision aid and were predicted to have no chance of being discharged from the hospital. Only 3 of these patients (1.1%) were discharged from the hospital (negative predictive value = 98.9%), none of whom were able to live independently following discharge from the hospital.

CONCLUSION

This decision aid can be used to help physicians identify patients who are extremely unlikely to benefit from continued resuscitative efforts.

Characteristics of cystic breast disease with special regard to breast cancer development

BACKGROUND

This prospective study compares the characteristics of cystic disease of the breast (CDB) of patients who developed breast cancer (BCa) during the follow-up (1.25-4 years) period with those who did not.

MATERIALS AND METHODS

K+, Na+, albumin, dehydroepiandrosterone (DHA), DHA-sulphate, oestrone, oestradiol, testosterone and progesterone levels were determined in breast cyst fluid (BCF). Patients presented data about their menstrual status, reproductive history, lactation period, date of first and the number of BCF aspirations, gynaecological interventions, use of oral contraceptives, family history of cancer, smoking habits and coffee consumption. The BCa incidence of patients was compared with the expected number of BCas in an age-matched group of 5143 women.

RESULTS

Out of 147 patients 6 developed BCa. The standardized incidence rate was 6.29. There were significant differences in testosterone, oestrone and progesterone levels and also reproductive history of patients who developed BCa compared with patients without BCa.

CONCLUSION

The above markers outline a subgroup of patients with the highest BCa risk.

Resuscitation in the hospital: relationship of year and rhythm to outcome

OBJECTIVE

determine the frequency of initial rhythms in in-hospital resuscitation and examine its relationship to survival. Assess changes in outcome over time.

METHODS

retrospective cohort (registry) including all admissions to the Medical Center of Central Georgia in which a resuscitation was attempted between 1 January, 1987 and 31 December, 1996.

RESULTS

the registry includes 3327 admissions in which 3926 resuscitations were attempted. Only the first event is reported. There were 961 hospital survivors. Survival increased from 24.2% in 1987 to 33.4% in 1996 (chi(2)=39.0, df=1, P<0.0001). Survival was affected strongly by initial rhythm (chi(2)=420.0, df=1, P<0.0001) and decreased from 63.2% for supraventricular tachycardia (SVT) to 55.3% for ventricular tachycardia (VT), 51.0% for perfusing rhythms (PER), 34.8% for ventricular fibrillation (VF), 14.3% for pulseless electrical activity (PEA) and 10.0% for asystole (ASYS). PEA was the most frequent rhythm (1180 cases) followed by perfusing (963), asystole (580), VF (459), VT (94) and SVT (38).

DISCUSSION

the powerful effect of initial rhythm on survival has been reported in pre-hospital and in-hospital resuscitation. VF is considered the dominant rhythm and generally accounts for the most survivors. We report good outcome for each; however, VF represents only 13.8% of events and 16.7% of survivors. PEA accounts for more survivors (169) than does VF (160). Our improved outcome is partially explained by changes in rhythms, but other institutional variables need to be identified to fully explain the results. Further studies are needed to see if our findings can be sustained or replicated.

Recurrent pericarditis after thoracic surgery

Acute pericarditis is a frequent complication after cardiac and/or thoracic surgery. Recurrent acute pericarditis with multiple episodes is an uncommon phenomenon, however. Patients typically have chest pain and/or pericardial inflammation as shown by electrocardiography and echocardiography. Treatment presents a clinical challenge due to the condition's rarity and lack of multicenter comparative treatment studies. Numerous therapeutic modalities, including nonsteroidal anti-inflammatory agents (NSAIDs), corticosteroids, immunosuppressants, and pericardiectomy, have been used without overwhelming evidence of a standard protocol. We report a case in which 32 episodes of recurrent acute pericarditis occurred, emphasizing the need for multicenter trials comparing therapeutic modalities in the future.

In-hospital resuscitation: association between ACLS training and survival to discharge

CONTEXT

No data have been published on the relationship between advanced cardiac life support (ACLS) training of the individual who initiates resuscitation efforts and survival to discharge.

OBJECTIVE

To determine whether patients whose arrests were discovered by nurses trained in ACLS had survival rates different from those discovered by nurses not trained in ACLS.

DESIGN

Cohort case-comparison.

SETTING

A 550-bed, tertiary care center in central Georgia.

SUBJECTS

Patients whose cardiopulmonary arrest was discovered by a nurse who activated the in-hospital resuscitation mechanism.

MAIN OUTCOME MEASURE

Patient survival to discharge.

RESULTS

Initial rhythm was strongly related to survival to discharge and individually associated with 57% of the variability in survival. Nurse's training in advanced cardiac life support was also strongly related to survival and individually associated with 29% of the variability. Combining both the variables determined 62% of the variability in survival to discharge. Patients discovered by an ACLS-trained nurse (n=88) were about four times more likely to survive (33 survivors, 38%) than were patients, discovered by a nurse without training in ACLS (n=29, three survivors, 10%).

CONCLUSION

Arrest discovery by nurses trained in ACLS is significantly and dramatically associated with higher survival-to-discharge rates.

Influence of hormonal status of patients with cystic disease on the composition of cyst fluid and breast cancer risk

The relationship between the composition of breast cyst fluid (BCF), the menstrual status and in addition some endocrine events in the history of patients (n = 131) with gross cystic breast disease was investigated. The dehydroepiandrosterone (DHA) levels in type II (K+/Na+ < 1) cysts of the follicular group were significantly higher compared to the type II cysts of the luteal or postmenopausal groups. For testosterone a significant difference existed between the type I (K+/Na+ > or = 1) follicular and type I postmenopausal groups. Estrone levels were significantly higher in type I BCF of patients in the luteal phase compared to both the follicular and postmenopausal type I cysts. Progesterone levels were lowest in the postmenopausal subgroups (both in type I and II cyst). Significant correlations were found between the number of pregnancies and the levels of DHA-sulfate and also progesterone in BCF. DHA levels were correlated with the period of lactation. The K+/Na+ ratios were the lowest in women who lactated for the longest period. The estrone was lowest in BCF of current oral contraceptive (o.c.) users while the estradiol was lowest in patients who had never used o.c. A history of previous o.c. use was associated with a significantly high mean DHA level. A significantly higher DHA and lower testosterone level were demonstrated in BCF of patients who had some previous gynecological interventions. The composition of BCF and the "life of cysts" and thus the rate of breast cancer risk may depend on hormonal status during the menstrual cycles or postmenopause and also on endocrine history of patients.

Resuscitation in the hospital: differential relationships between age and survival across rhythms

OBJECTIVE

Assess the frequency and outcome of inhospital resuscitation and determine the relationship between patient age and survival and whether it is affected by initial rhythm.

DESIGN

Retrospective, single-institution, registry study of inhospital resuscitation.

SETTING

A 550-bed, tertiary-care, teaching hospital in Macon, GA.

PATIENTS

All admissions for which a resuscitation was attempted in the Medical Center of Central Georgia during the period of January 1, 1987 through December 31, 1993. The registry sample included 2,394 admissions, for which 2,813 resuscitation attempts were made; only the first resuscitation attempt during an admission was analyzed.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Rates of survival to discharge steadily increased from 24.4% in 1987 to 38.6% in 1993; the overall survival rate was 26.8%. Age, used as a continuous variable, was strongly related to survival (odds ratio = 0.984; p < .0001). Categorically, overall survival rates for pediatric, adult, and geriatric patients were 56.4%, 29.0%, and 24.0%, respectively. Survival rates also varied significantly (odds ratio = 0.469; p < .0001) among initial rhythms, i.e., supraventricular tachycardia (60.7%), ventricular tachycardia (57.6%), perfusing rhythms (49.84%), ventricular fibrillation (32.0%), pulseless electrical activity (14.6%), and asystole (9.1%). The relationship between age and survival did not change across the years included in the study, but did vary as a function of initial rhythm (p < .0001). Age was positively related to survival when initial rhythm was supraventricular tachycardia (p = .04), negatively related to survival when the initial rhythm was perfusing (p < .0001) or pulseless electrical activity (p = .0002), and not related to survival when the initial rhythm was ventricular tachycardia (p = .98), ventricular fibrillation (p = .14), or asystole (p = .21).

CONCLUSIONS

The relationship between patient age and a successful resuscitation attempt is not as simple as reported earlier. Whether age is related to increased or decreased survival, or is unrelated to survival, depends on the rhythm extant when resuscitation attempts begin. Survival rates were higher than most reported elsewhere and improved significantly over time. Multicentered studies are needed to determine whether these results are unique to the institution studied.

The effect of regulation of high blood pressure on plasma endothelin-1 levels in blacks with hypertension

Plasma concentrations of immunoreactive endothelin-1 (irET-1) are significantly elevated in blacks with hypertension. In the present study, we investigated the effect of the regulation of high blood pressure on plasma irET-1 levels in black hypertensive individuals. After the initial blood samples were collected from 20 black patients with uncontrolled high blood pressure (Day 1), an intensive antihypertensive treatment was initiated, and the blood pressure and plasma irET-1 levels were monitored on days 2, 8, and 22. When the high blood pressure was brought under control with commonly used antihypertensive medications, plasma irET-1 concentrations dropped dramatically, suggesting that ET-1 concentrations rise as a consequence of high blood pressure in this study group.

Effect of advanced cardiac life support training on resuscitation efforts and survival in a rural hospital

STUDY OBJECTIVE

To determine the impact of an Advanced Cardiac Life Support (ACLS) training program on resuscitation and survival in a rural hospital.

METHODS

Retrospective review of arrests in a 119-bed rural community hospital before, during, and after organization of an ACLS teaching program. ICU logs, death logs, and code review sheets were used to determine resuscitation efforts and outcomes; these were cross-checked with medical and administrative records. From 1980 through 1984, resuscitation attempts were conducted only in the ICU. By 1985, after the training program was instituted, resuscitation efforts were conducted throughout the hospital. Data are presented on resuscitations in the ICU only and on total hospital resuscitations. To assess effort, resuscitation attempts and successes were compared with total death events (ie, total number of hospital deaths plus total number surviving a resuscitation effort).

RESULTS

From 1980 through 1984, before ACLS training was instituted, 42 patients were resuscitated and 15 (36%) survived to discharge. From 1985 through 1987, 113 ICU patients were resuscitated and 29 (26%) survived. From 1988 through 1990, after ACLS protocol and code review procedures were established, 81 ICU patients were resuscitated and 23 (28%) survived. The number of attempted resuscitations throughout the hospital increased from 42 in the early period to 179 in the final period, with 15 (36%) and 52 (29%) survivors, respectively. Rates of ICU or hospital-wide resuscitation success were not significantly different over time (P > .3). There were 893 total death events in the early period and 485 in the final period. The percentage of death events with an intervention rose from 5% to 37% (P < .001), and the percentage reversed by intervention increased from 2% to 11% (P < .001).

CONCLUSION

After widespread ACLS training and code team organization, there was a significant increase in resuscitation efforts and reversal of death events despite a slight decline in the percentage of patients surviving resuscitation attempts. An ACLS training program in a rural hospital can contribute to increased overall survival.

Racial differences in plasma endothelin-1 concentrations in individuals with essential hypertension

Hypertension is more prevalent in blacks than whites, and the reasons for this difference remain unclear. To test whether endothelin may play a role in these racial variations, we analyzed plasma samples from black and white women and men with high blood pressure by an enzyme-linked immunoassay specific for endothelin-1 (ET-1), a potent vasoconstrictor, and compared them with those obtained from similar subjects with normal blood pressure. Both female and male hypertensive blacks had elevated levels of immunoreactive ET-1 (11.3 +/- 1.0 and 12.3 +/- 1.3 pmol/L, respectively) compared with values in normotensive control blacks (1.5 +/- 0.2 and 1.4 +/- 0.2 pmol/L). Corresponding values in female and male hypertensive whites were 3.8 +/- 0.6 and 3.8 +/- 0.6 pmol/L, respectively, compared with respective values of 1.4 +/- 0.1 and 2.8 +/- 0.4 pmol/L in normotensive control whites. These results indicate that plasma concentrations of immunoreactive ET-1 levels differ significantly between black and white individuals with high blood pressure. This finding may be an important factor in the etiology of racial differences in the prevalence and severity of hypertension and deserves further study [corrected].

Angiotensin-converting enzyme and enkephalinase in human breast cyst fluid

Palpable breast cysts with an apocrine epithelial lining (type 1) are reported to be associated with a higher risk of developing breast cancer. The composition of breast cyst fluid (BCF) might include those factors involved in this increased risk. In this study peptidase activities that were active against the substrate [125I]metenkephalin-Arg-Phe were detected in BCF. The products were identified by reversed phase high-performance liquid chromatography (HPLC) as [125I]Tyr-Gly-Gly and [125I]Met-enkephalin. This proteolysis was not inhibited by PCMB, pepstatin A, leupeptin or aprotinin but was by EDTA, showing that the activity was due to metalloproteases. The production of [125I]Try-Gly-Gly was inhibited by phosphoramidon and thiorphan, whereas that of [125I]met-enkephalin was inhibited by captopril and Bothrops jararaca peptide, indicating that these activities are enkephalinase and angiotensin-converting enzyme (ACE) respectively. A fluorometric assay for ACE demonstrated that ACE levels are significantly higher in type 2 BCF than in type 1 BCF (30.8 vs 6.1 nmol hr-1 10 microliters-1, P < 0.001). As the increased risk of cancer is linked to type 1 cysts it is possible that higher levels of peptidase in type 2 BCF reflect a protective environment in the breast in which mitogenic peptide growth factors are neutralised by proteolysis.

Met-enkephalin Arg-Phe-immunoreactive neurons in the central nervous system of the pond snail Lymnaea stagnalis

The distribution of an opioid peptide related to YGGFMRF was determined in the CNS and other organs of the pond snail, Lymnaea stagnalis, by RIA and immunocytochemistry. RIA revealed the highest levels in the CNS (1 pmol/organ) and penis (400 fmol/organ). There were also significant levels in the haemolymph, most of which was not associated with haemocytes (580 fmol/ml). Both serial section and whole-mount immunocytochemistry of the CNS revealed immunoreactive cells in every ganglion with the majority in the cerebral and pedal ganglia. In the pedal ganglia some of the immunoreactive cells were close to the cells of the A-cluster, which are known to respond to opioids, and could innervate them. In the cerebral ganglia the immunoreactive cells included a group of neurosecretory cells, the caudo dorsal cells (CDCs) and the terminals of these cells in the cerebral commissure were also stained. The CDCs secrete peptides into the haemolymph and so could be the source of the YGGFMRF immunoreactivity. Immunoreactivity (including the CDCs) was observed in locations that correspond to those reported for other fragments of proenkephalin, such as Met- and Leu-enkephalin, suggesting that they may share a common precursor, a Lymnaea proenkephalin. A map of the 358 YGGFMRF-immunoreactive cells in the CNS is presented, many of which have not been previously identified.

Direct peptide profiling by mass spectrometry of single identified neurons reveals complex neuropeptide-processing pattern

A novel strategy combining peptide fingerprinting of single neurons by matrix-assisted laser desorption ionization mass spectrometry, molecular cloning, peptide chemistry, and electrospray ionization mass spectrometry was used to study the intricate processing pattern of a preprohormone expressed in identified neurons, the neuroendocrine light yellow cells (LYCs) of the gastropod mollusc, Lymnaea stagnalis. The cDNA encoding the precursor, named prepro-LYCP (LYCPs, light yellow cell peptides), predicts a straightforward processing into three peptides, LYCP I, II, and III, at conventional dibasic processing sites flanking the peptide domains on the precursor. However, matrix-assisted laser desorption ionization mass spectrometry of single LYCs revealed trimmed variant peptides derived from LYCP I and II. The variants were much more abundant than the intact peptides, indicating that LYCP I and II serve as intermediates in a peptide-processing sequence. Using the molecular masses of the peptides as markers to guide their isolation by well established purification methods, the structural identities of the peptides could be confirmed by amino acid sequencing. Furthermore, matrix-assisted laser desorption ionization mass spectrometry could detect colocalization of a novel peptide with the LYCPs.

Separation of ovine chromaffin granules from lysosomes by successive isoosmolar and hyperosmolar density gradient centrifugation

Preparations containing ovine chromaffin granules and lysosomes were obtained by differential centrifugation and applied to density gradients. In isoosmolar linear Metrizamide gradients the granules had a lower density than the major portion of the lysosomes (1.05 compared to 1.15); however, in hyperosmolar linear Metrizamide gradients the granule density increased and they migrated close to the lysosomes. The granules separated into two bands on a discontinuous isoosmolar Metrizamide gradient; however, these two bands were similar in terms of granule and lysosomal markers. On a discontinuous hyperosmolar sucrose gradient the granules were more dense than the lysosomes, the reverse of the situation on the Metrizamide gradient. Separation on a discontinuous isoosmolar Metrizamide gradient followed by a 1.8 M sucrose cushion provided a 54-fold purification of granules from lysosomes and similar separations from other subcellular markers. This procedure also provided a 37-fold purification of bovine granules from lysosomes. It was demonstrated that thimet oligopeptidase (EC 3.4.24.15) occurred in the adrenal medulla but is not principally located in the chromaffin granule.