Electrocardiographic manifestations of pulmonary embolism.

The electrocardiogram (ECG) may be entirely normal in the patient with pulmonary embolism (P/E); alternatively, any number of rhythm and/or morphologic abnormalities may be observed in such a patient. The abnormal ECG may deviate from the norm with alterations in rhythm, in conduction, in axis of the QRS complex, and in the morphology of the P wave, QRS complex, and ST segment/T wave. The electrocardiographic findings associated with PE are numerous, including arrhythmias (sinus tachycardia, atrial flutter, atrial fibrillation, atrial tachycardia, and atrial premature contractions), nonspecific ST segment/T wave changes, T wave inversions in the right precordial leads, rightward QRS complex axis shift and other axis changes, S1Q3 or S1Q3T3 pattern, right bundle branch block, and acute cor pulomnale. This review focuses on the ECG and the various abnormalities seen in the patient with PE.

Electrocardiographic ST-segment elevation: the diagnosis of acute myocardial infarction by morphologic analysis of the ST segment.

UNLABELLED: Acute myocardial infarction (AMI) is one of many causes of ST-segment elevation (STE) in emergency department (ED) chest pain (CP) patients. The morphology of STE may assist in the correct determination of its cause, with concave patterns in non-AMI syndromes and non-concave waveforms in AMI. OBJECTIVES: To determine the impact of STE morphologic analysis on AMI diagnosis and the ability of this technique to separate AMI from non-infarction causes of STE. METHODS: The electrocardiograms (ECGs) of consecutive ED adult CP patients (with three serial troponin I determinations) were interpreted in two-step fashion by six attending emergency physicians (EPs): 1) the determination of STE by three EPs followed by 2) STE morphologic analysis (either concave or non-concave) in those patients with STE. The impact of STE morphology analysis was investigated in the identification of AMI and non-AMI causes of STE. Acute myocardial infarction was diagnosed by abnormal serum troponin I values (>0.1 mg/dL) followed by a rise and fall of the serum marker; STE diagnoses of non-AMI causes were determined by medical record review. Interobserver reliability concerning STE morphology was determined. Study inclusion criteria included at least three troponin values performed in serial fashion no more frequently than every three hours, initial ED ECG, ED diagnosis, and final hospital diagnosis. RESULTS: Five hundred ninety-nine CP patients were entered in the study, with 171 (29%) individuals having STE on their ECGs. Of the 171 patients who had STE, 56 had AMI, 50 had unstable angina pectoris (USAP), and 65 had non-coronary final diagnoses. Forty-nine patients had non-concave STE, 46 with AMI and three with USAP; no patient with a non-coronary diagnosis had a non-concave STE morphology. The sensitivity and specificity of the non-concave STE morphology for AMI diagnoses were 77% and 97%, respectively; the positive and negative predictive values for non-concave morphology in AMI diagnoses were 94% and 88%, respectively. Interobserver reliability in the STE morphology determination revealed a kappa coefficient of 0.87. CONCLUSIONS: A non-concave STE morphology is frequently encountered in AMI patients. While the sensitivity of this pattern for AMI diagnosis is not particularly helpful, the presence of this finding in adult ED chest pain patients with STE strongly suggests AMI. This technique produces consistent results among these EPs.

Case management and quality of life: assessing treatment and outcomes for clients with chronic and persistent mental illness.

OBJECTIVE: To examine the impact of treatment setting and exposure to case management services on the quality of life of U. S. veterans with chronic and persistent mental illness. DATA SOURCES/STUDY SETTING: Data were collected longitudinally on a panel of 895 clients enrolled in 14 pilot programs in Department of Veterans Affairs long-term psychiatric hospitals by the Serious Mental Illness Treatment Research and Evaluation Center during the period 1991-96. STUDY DESIGN: Data were collected using two primary survey instruments (clinician assessment and client assessment) at baseline, every six months for the first two years, and every year thereafter, for a total of four years of follow-up. Case management exposure over time and its impact on the client's quality of life represent the key variables in the study. Additional controls included a variety of sociodemographic, socioeconomic, and psychiatric characteristics. DATA COLLECTION/EXTRACTION METHODS: Hierarchical linear modeling was used to control for potential selection bias, test for the compositional effect of treatment setting, and examine the impact of case management exposure over time on the individual client's quality of life. PRINCIPAL FINDINGS: Increased exposure to case management results in an improved quality of life across several domains, including both objective and subjective dimensions for health, general, leisure, and social, and the subjective dimension only for housing. CONCLUSIONS: The study findings provide managers, clinicians, and policymakers a fuller understanding of how this mode of service delivery-case management-affects several domains of quality of life for clients with chronic illnesses.

Errors in emergency physician interpretation of ST-segment elevation in emergency department chest pain patients.

OBJECTIVE: To determine the rate of error in emergency physician (EP) interpretation of the cause of electrocardiographic (ECG) ST-segment elevation (STE) in adult chest pain patients. METHODS: The authors conducted a retrospective ECG review of adult chest pain patients in a university hospital emergency department (ED) over a three-month period (January 1 to March 31, 1996). ST-segment elevation was determined to be present if the ST segment was elevated >/=1 mm in the limb leads and >/=2 mm in the precordial leads in at least two anatomically contiguous leads. Initial EP ECG interpretation was compared with the final interpretation by a cardiologist supported by the results of various clinical investigations. The rate of incorrect ECG diagnosis was calculated. RESULTS: Two hundred two patients had STEs. The rate of ECG STE misinterpretation was 12 of 202 (5.9%). The most frequently misdiagnosed form of STE was left ventricular aneurysm, for which two of five cases were believed to represent acute myocardial infarction (AMI). The benign early repolarization (BER) pattern was the second most frequently misinterpreted STE entity-in a total of three cases, two were initially noted to represent pericarditis and one AMI. ST-segment elevation resulting from actual AMI was initially incorrectly noted to be noninfarction in etiology in two cases, one patient with BER and the other with left ventricular hypertrophy. CONCLUSIONS: Emergency physicians show a low rate of ECG misinterpretation in the patient with chest pain and STE. The clinical consequences of this misinterpretation are minimal.

Effectiveness of specialized treatment programs for veterans with serious and persistent mental illness: a three-year follow-up.

This is the first study to test concurrently the effectiveness of four treatment programs for patients with serious mental illness. Three-year outcome data on utilization and functioning demonstrated important positive changes for seriously mentally ill veterans enrolled in specialized, enhanced inpatient and community case management treatment programs, when compared to patients in an enhanced day treatment program or traditional standard care.

Branch migration inhibition in PCR-amplified DNA: homogeneous mutation detection.

A novel method for detection of any mutation located within a PCR-amplified DNA sequence was demonstrated. The method is based on the inhibition of spontaneous DNA branch migration. Partial duplexes produced by PCR amplification of a test and a reference genomic DNA sample anneal to form four-stranded cruciform structures. Spontaneous DNA branch migration results in dissociation of these structures when the test and reference sequences are identical. Any base substitution, deletion or insertion inhibits branch migration and produces stable cruciform structures. When suitable ligands are attached to the PCR primers, the cruciform structures can be detected by standard immunochemical methods. This approach was tested using several commonly occurring mutations within the human cystic fibrosis gene. New methods for increasing the specificity of PCR amplifications are described that were used for successful mutation analysis.

Repeated assaults by patients in VA hospital and clinic settings.

OBJECTIVE: The study aim was to determine the prevalence of repeated assaults on staff and other patients and characteristics of patients who commit repeated assaults in the Veterans Health Administration of the Department of Veterans Affairs. METHODS: Patients in VA medical centers and freestanding outpatient clinics who committed two or more assaults in fiscal years 1995 and 1996 were identified through a survey of facility quality or risk managers. For each repeatedly assaultive patient, structured information, including incident reports, was obtained for all assault occasions. RESULTS: A total of 153 VA facilities responded, for a response rate of 99 percent. The survey identified 8,968 incidents of repeated assault by 2,233 patients, for a mean of 4.02 assaults per patient in the two-year study period. In 92 percent of the incidents, the assaultive patient had a primary or secondary psychiatric diagnosis. The mean age of the repeat assaulters was 62 years. Ninety-eight percent of the repeat assaulters were male, and 76.6 percent were Caucasian. At least 16 percent of the assaulters, 22 percent of the patients assaulted, and 20 percent of the staff assaulted required medical attention for injuries, which, along with the number of lost work days, indicates that repeated assaults are costly. CONCLUSIONS: Repeatedly assaultive patients represent major challenges to their own safety as well as to that of other patients and staff. Identifying patients at risk for repeated assaults and developing intervention strategies is critically important for ensuring the provision of health care to the vulnerable population of assaultive patients.

A causal model of voluntary turnover among nursing personnel in long-term psychiatric settings.

Causal modeling was used to explore the processes by which individual characteristics, job satisfaction, and intention to quit explain turnover among nursing personnel in 29 Department of Veterans Affairs (VA) long-term psychiatric settings. The sample consisted of 1,106 registered nurses (RNs), licensed practical nurses (LPNs), and nurses' aides. We conceptualized turnover as a multistage process linking social and experiential orientations, attitudes toward the job, the decision to quit, and the behavior of actually quitting. Intention to quit was the strongest direct predictor of turnover. Professional growth opportunities and workload were important indirect predictors of turnover. Dissatisfaction with work hazards and relationships with coworkers were both indirect and direct predictors of turnover. Attitudes towards the job varied by nursing group. LPNs and aides were less satisfied than RNs with autonomy and work hazards. RNs were more dissatisfied with workload. We conclude that strategies to promote retention need to address aspects of jobs tailored to specific nursing groups.

Agreement between seriously mentally ill veterans and their clinicians about medication compliance.

OBJECTIVES: Levels of agreement about medication compliance in a large cohort of seriously mentally ill veterans and their clinicians were examined to determine whether agreement increased with exposure to enhanced treatment programs emphasizing compliance and whether compliance reports were associated with hospitalization. METHODS: A total of 1,369 seriously mentally ill patients and their treating clinicians at 14 Veterans Affairs medical centers rated medication compliance at enrollment in enhanced programs or comparison programs offering standard care. Patients and clinicians reassessed compliance one and two years after enrollment. Overall agreement, agreement about compliance and noncompliance, and kappa statistics were determined for concurrent assessments. RESULTS: Overall, patients rated themselves as significantly more compliant with medication than did clinicians at enrollment. Cohen's kappa at enrollment was .095, indicating little patient-clinician agreement beyond that expected by chance. Kappa values increased significantly at one and two years for patients in the enhanced programs but continued to indicate poor-to-modest levels of agreement. Patient-clinician pairs in enhanced programs did not differ from those in comparison programs in overall agreement. Reports of good compliance by both patients and clinicians were associated with significantly decreased odds of hospital admission in the 30 days after the report was made. CONCLUSIONS: Seriously mentally ill patients and their clinicians showed little agreement about medication use beyond that expected by chance. Intensive programming appeared to have little effect on agreement. Both patients' and clinicians' compliance assessments predicted hospitalization and thus can be used in research models that attempt to predict relapse and readmission.

Determinants of mental health providers' expectations of patients' improvement.

OBJECTIVE: Characteristics of individual mental health providers and of treatment settings were examined to determine their effects on providers' expectations about the improvement of patients with serious mental illness. METHODS: The sample consisted of 1,567 treatment providers working in 107 inpatient and outpatient units or programs in 29 Veterans Affairs mental health facilities. They completed a questionnaire about their prognostic expectations and a broad range of attitudes toward job satisfaction, professional relations, and team functioning. Unit or program directors of all 107 units completed another questionnaire about the average functional ability of patients, unit workload, and unit size. Hierarchical linear modeling was used to assess the effects of both individual and unit-level attributes on providers' expectations of improvement in clinical symptomatology and social-functional skills of patients in their care. RESULTS: The providers had generally low expectations about the improvement of patients with serious mental illness. Expectations were higher among staff in units or programs that were smaller and that had an outpatient focus, a greater proportion of staff involved in the treatment team, and higher-functioning patients. Individual characteristics significantly associated with prognostic expectations were occupation, age, and membership on the treatment team. CONCLUSIONS: Prognostic expectations among providers of care to persons with serious mental illness vary with identifiable individual and unit or program characteristics. The latter may be amenable to manipulation and intervention to improve mental health providers' prognostic expectations.

Luminescent oxygen channeling assay (LOCI): sensitive, broadly applicable homogeneous immunoassay method.

Luminescent oxygen channeling assay (LOCI) is a homogeneous immunoassay method capable of rapid, quantitative determination of a wide range of analytes--including high and very low concentrations of large and small molecules, free (unbound) drugs, DNA, and specific IgM. Assays have been carried out in serum and in lysed blood. Reliable detection of 1.25 microU/L thyrotropin (TSH) and 5 ng/L hepatitis B surface antigen (HBsAg) corresponds to detection limits approximately 3- and approximately 20-fold lower, respectively, than those of the best commercially available assays. An assay of chorionic gonadotropin is capable of quantification over a 10(6)-fold range of concentrations without a biphasic response. Latex particle pairs are formed in the assay through specific binding interactions by sequentially combining the sample and two reagents. One particle contains a photosensitizer, the other a chemiluminescer. Irradiation causes photosensitized formation of singlet oxygen, which migrates to a bound particle and activates the chemiluminescer, thereby initiating a delayed luminescence emission. Assay times range from 1 to 25 min.

The effects of treatment team diversity and size on assessments of team functioning.

Team-based health care assumes that groups representing multiple disciplines can work together to implement care plans that are comprehensive and integrated. It also assumes that professionals can function effectively in an interdependent relationship with members of other occupational groups. However, we know little about what makes effective team functioning. This article examines the factors related to health care team functioning, with specific emphasis on team demographic composition and size. Hierarchical linear modeling is used to analyze 106 Veterans Affairs (VA) hospitals. Results indicate that individuals who operate on more heterogenous and larger teams have lower perceptions of team functioning.

Formation of chimeric DNA primer extension products by template switching onto an annealed downstream oligonucleotide.

Oligodeoxynucleotide sequences are described that anneal to a template downstream of a priming site. During polymerase-catalyzed extension of the primer, the extending primer shifts from the original template to a segment of the annealed oligonucleotide that acts as an alternative template. The resulting chimeric extended primer has one segment that is complementary to the template and a second segment that is complementary to the oligonucleotide. The influence of the sequence elements of the oligonucleotide and the reaction conditions on template switching have been explored. The sequence requirements for template switching are compared to those for transposon excision.

DELISA: sensitive nonisotopic assay for GAD65 autoantibodies, a key risk-assessment marker for insulin-dependent diabetes mellitus.

Nonisotopic assays for the measurement of autoantibodies to 65-kDa glutamic acid decarboxylase (GAD65) have not previously achieved performance equivalent to radiobinding assays (RBA). We have developed a modified ELISA protocol, DELISA, for measuring autoantibodies to GAD65 in serum. The method overcomes the problems of poor sensitivity and specificity associated with conventional ELISAs. Serum containing GAD65 autoantibodies is incubated with biotinylated GAD65 (bGAD65). Sufficient soluble Protein A-dextran conjugate is added to bind the immunoglobulins in the sample, including GAD65 autoantibodies to which GAD65 is bound. After incubation, the mixture is transferred to a streptavidin-p4ated microtiter well, which binds free bGAD65 but not bGAD65 bound to autoantibodies. Streptavidin-bound bGAD65 is detected by means of a peroxidase-GAS65MAb conjugate. The method appears to have comparable sensitivity and specificity to those of RBAs. Reaction of the antibodies with soluble antigen to increase the binding rate and the use of high serum concentrations and very low antigen concentrations to increase sensitivity are critical elements of the method.

Luminescent oxygen channeling immunoassay: measurement of particle binding kinetics by chemiluminescence.

A method for monitoring formation of latex particle pairs by chemiluminescence is described. Molecular oxygen is excited by a photosensitizer and an antenna dye that are dissolved in one of the particles. 1 delta gO2 diffuses to the second particle and initiates a high quantum yield chemiluminescent reaction of an olefin that is dissolved in it. The efficiency of 1 delta gO2 transfer between particles is approximately 3.5%. The technique permits real-time measurement of particle binding kinetics. Second-order rate constants increase with the number of receptor binding sites on the particles and approach diffusion control. By using antibody-coated particles, a homogeneous immunoassay capable of detecting approximately 4 amol of thyroid-stimulating hormone in 12 min was demonstrated. Single molecules of analyte produce particle heterodimers that are detected even when no larger aggregates are formed.

An automated enzymatic method for measurement of D-arabinitol, a metabolite of pathogenic Candida species.

An automated enzymatic method was developed for the measurement of D-arabinitol in human serum. The assay is based on a novel, highly specific D-arabinitol dehydrogenase from Candida tropicalis. This enzyme catalyzes the oxidation of D-arabinitol to D-ribulose and the concomitant reduction of NAD+ to NADH. The NADH produced is used in a second reaction to reduce p-iodonitrotetrazolium violet (INT) to INT-formazan, which is measured spectrophotometrically. The entire reaction sequence can be performed automatically on a COBAS MIRA-S clinical chemistry analyzer (Roche Diagnostic Systems, Inc., Montclair, N.J.). Replicate analyses of human sera supplemented with D-arabinitol over a concentration range of 0 to 40 microM demonstrated that the pentitol could be measured with an accuracy of +/- 7% and a precision (standard deviation) of +/- 0.4 microM. Serum D-arabinitol measurements correlated with those determined by gas chromatography (r = 0.94). The enzymatic method is unaffected by L-arabinitol, D-mannitol, or other polyols commonly found in human serum. Any of 17 therapeutic drugs potentially present in serum did not significantly influence assay performance. Data illustrating the application of the assay in patients for possible diagnosis of invasive candidiasis and the monitoring of therapeutic intervention are presented. The automated assay described here was developed to facilitate the investigation of D-arabinitol as a serum marker for invasive Candida infections.

Relationship between early metabolic control and the development of microalbuminuria--a longitudinal study in children with type 1 (insulin-dependent) diabetes mellitus.

The cumulative incidence of microalbuminuria from onset up to 15 years of Type 1 (insulin-dependent) diabetes mellitus and the relative importance of age, duration, blood pressure and metabolic control for subsequent microalbuminuria was studied in 156 children. Urinary albumin excretion and HbA1c were followed at 3-month intervals from onset and systolic and diastolic blood pressure at the same interval from 5 years of diabetes. Persistent microalbuminuria over 20 micrograms/min developed in 17 children. The cumulative incidence by duration was 24.2% at 15 years of diabetes. Eleven patients developed microalbuminuria after more than 5 years. Among these, first 5-year mean HbA1c was 8.4 +/- 1.3% vs 7.2 +/- 1.1% in normoalbuminuric children (p < 0.001). The crude relative risk of developing microalbuminuria with a first 5-year mean HbA1c greater than 7.5% was 4.49 (95% confidence interval 1.13-17.84). The age- and duration-adjusted relative risk was 3.51% (0.90-14.42). The year before transition to microalbuminuria neither mean HbA1c nor yearly mean blood pressures, sex or age at onset of diabetes differed from normoalbuminuric children at the same diabetes duration. Age and duration were higher (p = 0.04). The relative importance of early vs later hyperglycaemia, yearly blood pressures, age, age at onset and duration of diabetes for increased albumin excretion rate after more than 5 years, was shown in a multiple regression analysis where the first 5-year mean HbA1c was the only independent predictor (p = 0.02). Six patients had an onset of microalbuminuria before 5 years of diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-immune complex antibodies enhance affinity and specificity of primary antibodies.

Antibodies have previously been described that enhance the binding of a second antibody to its antigen. The origin of this effect has been variously ascribed to binding to a neodeterminant on the Fc region, to a combined determinant representing portions of the second antibody and the immunogen, and to a ligand-induced conformation of the Fab fragment. This paper describes an antibody that recognizes an immune complex of an antibody to tetrahydrocannabinol (THC). The antibody binds the anti-THC antibody at an epitope recognized by an anti-idiotype antibody that is capable of blocking THC binding. The ability of various THC derivatives to enhance or inhibit binding taken together with equilibria and kinetic data support a model in which the anti-immune complex antibody interacts through adventitious binding to pendant groups on the THC derivatives. This type of interaction offers the opportunity to increase the sensitivity and specificity of immunoassays beyond the limits imposed by normal antibody binding. The implications of these findings with regard to earlier observations of anti-immune complex antibodies are discussed.