Quantitative (82)Rb PET/CT: development and validation of myocardial perfusion database.

The use of myocardial perfusion (82)Rb PET/CT studies continues to increase but its accuracy using database quantification methods for the diagnosis of coronary artery disease (CAD) has not been established. METHODS: A sex-independent normal database and criteria for abnormality for rest-stress (82)Rb PET/CT myocardial perfusion imaging were developed and validated by evaluation of 281 patients (136 females: mean age +/- SD, 63.3 +/- 13.3 y; 145 males: mean age +/- SD, 63.9 +/- 12.8 y) who underwent a rest-adenosine stress (82)Rb PET/CT study. These patients were divided into 3 groups: (a) healthy group: 30 patients, with <5% likelihood of CAD (low likelihood [LLK]) based on sequential Bayesian analysis; these patients were used to generate the normal distribution; (b) pilot group: 174 patients; these patients were used to determine the optimal criteria for detecting and localizing the perfusion abnormality; and (c) validation group: 76 patients (23 with LLK of CAD and 53 who underwent coronary angiography; these patients were used for prospective validation. RESULTS: Of the 53 patients who underwent coronary angiography, 8 had <50% stenosis and 45 patients had at least one stenosis > or =50% in one major artery. Fifteen patients had single-vessel disease, 17 had double-vessel disease, and 13 had triple-vessel disease. The prospective validation shows a normalcy rate of 78% (18/23) for global CAD. The analyses by individual arteries show a normalcy rate of 96% (22/23) for the left anterior descending coronary artery, 96% for the left circumflex coronary artery (22/23), and 100% for the right coronary artery (23/23). The overall sensitivity for detection of CAD (> or =50% stenosis) was 93% (42/45). The overall specificity for detection of the absence of CAD (< or =50% stenosis) was 75% (6/8). Also, the positive predictive value for global CAD was 95% (42/44), the negative predictive value was 67% (6/9), and the accuracy was 91% (48/53). CONCLUSION: The quantitative (82)Rb PET/CT database created and validated in this study is highly accurate for the detection and localization of CAD. Physicians should consider using the quantitative output of these algorithms as decision support tools to aid with image interpretation.     

Predictors of employment in substance-using male and female welfare recipients

This study examined predictors of employment among substance-using men and women enrolled in welfare-to-work programs. Participants were 394 welfare applicants assigned to either coordinated care management or usual care for treatment services and job training and followed up for 1 year to track employment outcomes. Common barriers to work were assessed at baseline in four key domains: disabilities, situational barriers, labor capital, and motivation. Results indicated substantial gender differences in the number and profile of work barriers. Among men, work experience and job motivation were the only significant predictors of employment; among women, multiple factors from each barrier domain predicted job acquisition even when controlling for all other significant predictors. Findings suggest that welfare-to-work programs should emphasize job training and job seeking during the early stages of welfare interventions for men and for many women.     

Expressed-emotion development and course of schizophrenic illness: considerations based on results of a CFI replication

This study examines the correlation between development of expressed emotion (EE) in relatives and course of illness of 99 DSM-III schizophrenic patients. Patients whose relatives were high EE at baseline and at the 2nd CFI approximately 20 months later had a poor prognosis at the very outset of the study and an unfavourable course of illness. They had a higher rehospitalisation rate, more symptoms, lower psychosocial assessment, and a poorer 2-year and even 8-year outcome. Patients from families with a fluctuating EE or a consistently low EE had better courses. Expessed emotion is therefore a valid predictor not only of symptomatic relapses, but also of other important aspects of schizophrenia. The connection between EE index and course of illness seerns not to be simply reactive or causal, but complex and non-uniform.     

Evidence for multiple xenogenous origins of plastids: comparison of psbA-genes with a xanthophyte sequence

Summary When only plastidic features are considered, it is difficult to distinguish between monophyletic and polyphyletic xenogenous origins of plastids. We suggest that a direct comparison of nuclear and plastidic sequence-similarity pattern will help to solve this problem. The D1 amino acid sequence of six major groups of photosynthetic eukaryotes and of the two groups of photosynthetic prokaryotes are now available, including the psbA-gene product from Bumilleriopsis filiformis, which is the first molecular sequence reported for a xanthophycean alga. Evidence is provided for an independent and polyphyletic origin of plastids from five out of the six major taxa of photosynthetic eukaryotes. This conclusion is reached by comparing a plastid-based pattern of D1 similarity with a nucleus-based similarity pattern published recently. Furthermore, the availability of D1 sequences from five eukaryotic algae led to a re-evaluation of the taxonomic position of Prochlorothrix.     

Growth promoting and metabolic activity of the human insulin analogue [Gly,Arg,Arg]insulin (HOE 901) in muscle cells

[Gly^A21,Arg^B31,Arg^B32]insulin (HOE 901) represents a biosynthetic human insulin analogue that, due to its isoelectric point, precipitates at neutral tissue pH leading to a retarded absorption rate and a corresponding longer duration of action. In the present investigation we have evaluated the growth promoting and metabolic activity of this analogue in muscle tissue using exponentially growing H9c2 cardiac myoblasts and adult rat ventricular cardiomyocytes. Equilibrium binding studies of ¹²⁵I-labelled IGF-I (insulin-like growth factor I) to differentiating myoblasts revealed the presence of 7×10³ IGF-I receptors per cell. In contrast, no specific binding of insulin could be detected. Competition binding experiments showed a slightly higher affinity of HOE 901 for the IGF-I receptor when compared to regular human insulin with IC₅₀ (half-inhibitory concentration) values of 70 and 101 nM, respectively. However, the supermitogenic insulin analogue [Asp^B10]insulin competed significantly more efficiently for IGF-I binding (IC₅₀: 44 nM). Maximum growth promoting activity of the peptides was then determined in serum-starved myoblasts by an incubation with the peptides (5×10⁻⁷ M) for 16 h in the presence of [³H]thymidine. [Asp^B10]Insulin produced a stimulation of DNA synthesis (about 3-fold) which was comparable to the effect of IGF-I and significantly (P<0.005) higher than the effect of HOE 901 with the latter being essentially equipotent to native insulin. Comparable results were obtained at lower concentrations of the peptides (10⁻⁹ to 10⁻⁸ M). Metabolic activity of HOE 901 was determined by measuring the dose-dependent stimulation of 3-O-methylglucose transport in adult cardiomyocytes. Maximum transport stimulation was identical for insulin and HOE 901 with EC₅₀ (half-effective concentration) values of 0.7×10⁻¹⁰ and 1.9×10⁻⁹ M, respectively. We concluded that the IGF-I receptor-mediated growth promoting activity of HOE 901 in muscle cells and the maximal metabolic activity of this analogue are not different from those of native human insulin. It is suggested that differential interaction with IGF-I receptors significantly contributes to the action profile of insulin analogues.     

Experiences with risk estimates for carriers of chromosomal reciprocal translocations

The risk estimates for individual carriers of ten different familial reciprocal translocations detected among 500 couples with reproductive failures are presented. These were established by application of the empirical data analysed by Stengel-Rutkowski et al. (1988) and the guidelines given in Stene & Stengel-Rutkowski (1988). Different risks were estimated for unbalanced offspring at birth or at second trimester prenatal diagnosis for abortions, or stillbirths/early deaths. These risk estimates varied considerably from translocation to translocation. Carriers of five translocations had risks for offspring with single-segment imbalances. The birth risk figures ranged from 0.1% to 13.8%. Carriers of five other translocations had risks for double-segment imbalances with birth risks ranging from 0% to 3.2%. The estimated risk figures were independent of the method of ascertainment. Among the parents of the index cases we found nine maternal carriers and only one paternal carrier. This presentation illustrates the need for individual risk counselling of each carrier with reciprocal translocation regarding further family planning.     

Revascularization of a thrombosed aortopulmonary shunt with the use of the AngioJet thrombectomy system.

We report the use of the AngioJet F140 rheolytic catheter to recannalize an acutely thrombosed aortopulmonary shunt in a 21-year-old female with palliated, complex congenital heart disease. After extracting the thrombus that filled the entire length of the shunt, three stents were placed at sites where the lumen was compromised by distortion or thrombus. Unobstructed flow was restored to the left pulmonary artery that persisted at 1-year follow-up.