Differences Between Treatment Seekers in an Obese Population: Medical Intervention vs. Dietary Restriction

This study examined two groups of people who were pursuing treatment for obesity: either medical intervention (a hospital group; N = 20) or support for dietary restriction (a community group; N = 18). This study addressed four questions: (1) Were there differences between the two groups in terms of their psychological distress (as measured by the Symptom Checklist)? (2) Does binge eating moderate psychological distress? (3) Do feelings of ineffectiveness moderate psychological distress? and (4) Which variables best accounted for group membership (i.e., type of treatment sought)? Results suggested that the hospital group was significantly more distressed than the community group. However, there were no differences between the two groups with respect to binge eating or feelings of ineffectiveness. These findings suggest that it is the effects of morbid obesity that are most likely to moderate psychological distress.     

Clinical aspects of the MASA syndrome in a large family, including expressing females

We have evaluated, both clinically and by linkage analysis, a large family with 22 known affected males with the MASA syndrome (McKusick 303300). Clinical findings varied widely amongst the affected family members, with some appearing initially to have the MASA syndrome and others to have X-linked hydrocephalus (HSAS) (McKusick 307000). Important findings included the presence of adducted thumbs in two obligate carriers, learning problems or mild mental retardation in three females, two of whom were obligate carriers, and hydrocephalus with neonatal death in three females born to obligate carriers. X-inactivation analysis in lymphocytes from the two women with adducted thumbs revealed preferential inactivation of one X chromosome, suggesting that nonrandom X-inactivation may be responsible for clinical expression in females. The presence of HSAS in some individuals of this family and the MASA syndrome in others further supports the hypothesis that these two conditions are the result of a mutation in the same gene.     

How can the evaluation of genetic tests be enhanced? Lessons learned from the ACCE framework and evaluating genetic tests in the United Kingdom.

Advances in genetic technology are increasing the availability of genetic tests, not only for rare single gene disorders, but also for common diseases such as breast and colo-rectal cancer. Before there can be widespread uptake of these tests, they must be evaluated to confirm the benefits of their use. But how should genetic tests be evaluated, given the speed at which new tests are emerging? One highly influential approach is the analytic validity, clinical validity, clinical utility and ethical, legal and social issues (ACCE) framework, which has provided a benchmark for the evaluation of genetic tests. The approach has been adopted and adapted by the United Kingdom Genetic Testing Network, with the help of the Public Health Genetics Unit in Cambridge, to evaluate new genetic tests for use in the National Health Service. We discuss a number of conceptual, methodological, and practical issues concerning the evaluation of genetic tests, based on lessons learned from applying the ACCE framework and from the UK experience, and make a number of recommendations to further strengthen the evaluation of genetic tests.     

Size distribution and In vitro translation of the RNAs isolated from turnip yellow mosaic virus nucleoproteins

Purified preparations of TYMV contain a number of minor nucleoprotein components distinguishable on the basis of their density in CsCl gradients (R. E. F. Matthews, Virology12, 521–539, 1960). When analysed by polyacrylamide-gel eletrophoresis, the RNA from each of these various components was found to consist of a characteristic set of molecular-weight species. Full-size RNA (2 × 10⁶ daltons) was present only in nucleoproteins B₁ and B₂. Nucleoproteins B₀, B₀₀, and B₀₀₀ contained RNAs ranging in size from approx 1.3 to 0.28 × 10⁶ daltons. The 0.28 × 10⁶-dalton RNA species was detectable in all nucleoprotein fractions, but was a significant proportion of the RNAs of B₀₀₀ and B₀₀. Translation of the RNA from each of the nucleoproteins in the wheat germ cell-free protein synthesizing system yielded essentially similar patterns of polypeptides which ranged in size from 5000 to 70,000 daltons. The major radioactive product migrated on SDS-polyacrylamide gels to the same position as TYMV coat protein. The data suggest that the 0.28 × 10⁶-dalton RNA component is the cistron for coat protein, and that it and other RNAs associated with TYMV infection are encapsidated.     

Internal quality assurance in a clinical virology laboratory. I. Internal quality assessment.

AIMS--In April 1991 an internal quality assessment scheme (IQAS) was introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. The IQAS was established to identify recurring technical and procedural problems, to check the adequacy of current techniques, and to calculate the frequency of errors. METHODS--Between April 1991 and December 1993, 715 anonymous clinical serum samples were submitted to the laboratory to test 3245 individual procedures of diagnostic viral serology. RESULTS--A total of 485 (14.9%) procedural and 61 (1.9%) technical discrepancies were observed, the technical discrepancies mainly being recorded in complement fixation tests. Twenty two (0.7% of total procedures) of the technical discrepancies were diagnostically significant. CONCLUSIONS--Evaluation criteria developed with the introduction of IQAS to viral serology, and technical and procedural discrepancies are assessed. As yet, IQAS has not been introduced to other sections of the diagnostic virology laboratory (virus isolation, electron microscopy, immunofluorescence, and enzyme linked immunosorbent assays for viral and chlamydial antigens).     

Internal quality assurance in a clinical virology laboratory. II. Internal quality control.

AIMS--In April 1991 additional quality control procedures were introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. Internal quality control (IQC) samples were gradually included in the serological assays performed in the laboratory and supplemented kit controls and standard sera. METHODS--From April 1991 to December 1993, 2421 IQC procedures were carried out with reference sera. RESULTS--The IQC samples were evaluated according to the Westgard rules. Violations were recorded in 60 of 1808 (3.3%) controls and were highest in the IQC samples of complement fixation tests (25/312 (8%) of controls submitted for complement fixation tests). CONCLUSIONS--The inclusion of IQC samples in the serological assays performed in the laboratory has highlighted batch to batch variation in commercial assays. The setting of acceptable limits for the IQC samples has increased confidence in the validity of assay results.     

Determination of left ventricular mass in dogs with rapid-acquisition cardiac computed tomographic scanning

The development of left ventricular hypertrophy in patients with heart disease often has far-reaching clinical implications with respect to overall morbidity and mortality. Approaches used to assess left ventricular mass include electrocardiography, echocardiography, contrast ventriculography, single photon-emission tomography, and conventional computed tomography. However, all of these modalities suffer from some major draw back that precludes widespread application to all patients. In this study we assessed the accuracy of determinations of left ventricular mass in 22 dogs by rapid-acquisition (50 msec) computed axial tomography (RACAT), an ultrafast computed tomographic (CT) instrument. Electrocardiographically triggered, end-diastolic, short-axis cardiac scans were obtained from apex to base during administration of intravenous iodinated contrast. Myocardial edges were determined for each tomographic scan by two methods: the regional half-contour method (the CT density half way between that of the left ventricular myocardium and adjacent ventricular cavities or lung) and "interactive plateau thresholding" of the cardiac borders. Left ventricular mass by RACAT was calculated as the sum of the mass of each individual scan from apex to base (modified Simpson's rule). Postmortem left ventricular mass ranged from 58 to 160 g. The correlation between true left ventricular mass and tomographically determined mass was excellent (r = .99), with the slope and y intercept not statistically different from 1 and 0, respectively. The standard error of the estimate was 4.1 g. Interobserver and intraobserver variability for determining left ventricular mass demonstrated excellent agreement (r = .99 and r = .99, respectively). We conclude that quantitative assessment of left ventricular mass can be accurately and reproducibly performed in dogs by rapid acquisition CT scanning. It is likely that this technique will be readily transferable to the clinical settings and prove to be an important method for quantifying left ventricular mass in patients.     

Preoperative radiation and surgery for cancer of the rectum. Veterans Administration Surgical Oncology Group Trial II

In a prospective randomized trial, 361 male patients with histologically proven adenocarcinoma of the rectum, judged preoperatively to require abdominoperineal resection (APR), were treated by surgery alone or were given 3,150 rads of preoperative radiotherapy. Surgical resection was done on 320 patients, 262 having "curative" APR. Only moderate symptoms from radiotherapy were noted and postoperative complications and 30-day mortality were similar in both groups. Five-year survival for curative APR was the same in both groups (50% for both treated and control patients). The incidence of positive lymph nodes in the resected specimens was 35% in treated and 41% in controls. In the first preoperative radiotherapy trial conducted by the group, 5-year survival in patients undergoing "curative" APR was 47% in treated versus 34% in control groups. Additionally, the difference in positive lymph nodes in the resected specimens was substantially greater in the first trial (26% in treated versus 44% in controls).     

Effects of retinoic acid versus dimethyl sulfoxide on Friend erythroleukemia cell growth. II. Induction of quiescent, nonproliferating cells

Treatment of Friend erythroleukemia (FL) cells in vitro with 10(-7) to 10(-5) all-trans-retinoic acid (RA) leads to a concentration-dependent accumulation of a subpopulation of quiescent cells. This subpopulation, termed "Q-cells," contained markedly reduced RNA and protein levels and had a cell cycle distribution with a predominance of cells in G1 phase, which was nearly identical to that found in fully differentiated dimethyl sulfoxide (CAS:67-68-5; methyl sulfoxide)-induced FL cultures. The G1 cells in this RA-induced subpopulation (G1Q cells), though viable, did not enter S-phase, whereas the small percentage of Q-cells with S and G2 DNA content progressed very slowly through the cycle. While the Q-cell population did not contain the differentiation-associated chromatin protein H1 degrees, the cells did manifest a more condensed nuclear chromatin, altered sensitivity to acid denaturation, and reduced accessibility of the DNA in chromatin to acridine orange. The extent of chromatin condensation and the number of free ribosomes versus polysomes in RA-treated FL cells were intermediate between those in untreated and fully differentiated cells, whereas viral budding and the number of nucleoli remained unchanged from those seen in the untreated cell state. The non-Q-cell population in RA-treated cultures, termed "T" (transitional) cells, had an intermediate RNA and protein content and a cell cycle distribution similar to those of control cultures nearing the plateau phase of growth. In the absence of any late markers of differentiation, the Q-cell population was tentatively identified as a unique, quiescent cell population not previously described in the FL cell system.