Unrecognized glucose intolerance is not associated with depression. Screening for Impaired Glucose Tolerance study 3 (SIGT 3).

AIMS: To understand the metabolic and temporal links in the relationship between diabetes and depression, we determined the association between depressive symptoms and unrecognized glucose intolerance. METHODS: In a cross-sectional study, 1047 subjects without known diabetes were screened for diabetes or pre-diabetes using the oral glucose tolerance test and for depressive symptoms using the Patient Health Questionnaire (PHQ). RESULTS: Mean age was 48 years, body mass index 30 kg/m(2); 63% were female, 54% black, 11% previously treated for depression and 10% currently treated; 5% had diabetes and 34% pre-diabetes. Median PHQ score was 2 (interquartile range 0-5). Depressive symptoms did not increase with worsening glucose tolerance, after adjusting for age, sex, ethnicity, body mass index, family history, exercise, education and depression treatment. CONCLUSIONS: There is no association between depressive symptoms and unrecognized glucose intolerance. However, it remains possible that diagnosed diabetes, with its attendant health concerns, management issues, and/or biological changes, may be a risk for subsequent development of depression. Thus, patients with newly diagnosed diabetes should be counselled appropriately and monitored for the development of depression.

Hybridoma stability.

Hybridoma stability issues include mutations, chromosome losses, and the potential effects of process variables on the yield, quality and homogeneity of the Monoclonal Antibody (MAb) product. MAb production by murine hybridomas is typically unstable in the early stages after fusion but repeated cloning normally produces stable clones. The stability of hybridomas and the consistency of the MAbs produced during extended high density perfusion cultures at Xoma Corporation were evaluated. Cell stability was assessed by recovering cells from the bioreactors at different intervals and comparing their growth and product formation kinetics and yields to those of cells started fresh from the corresponding Manufacturer's Working Cell Banks. Product consistency was evaluated in the crude harvests and in the corresponding purified MAb lots by biochemical and functionality tests including: SDS-PAGE (reducing and non-reducing), IEF, HPLC (size exclusion and cation exchange), peptide mapping, N-terminal sequencing, carbohydrate composition and binding assays. Several murine hybridomas were studied during runs lasting several months and found to be stable by all criteria employed. Such results support the viability of extended hollow fiber perfusion cultures for reproducible production of murine MAbs. Selecting stable clones and understanding the effects of process variables on the quantity and quality of the MAbs are keys to controlling hybridoma stability during the manufacturing process.

A reverse transcriptase-polymerase chain reaction assay for the detection and quantitation of murine retroviruses.

Specific hybridization primers for the PCR assay were developed to detect the presence of the ecotropic, xenotropic, and mink cell focus-forming classes of murine leukemia viruses (MuLVs) in samples derived from cultured cells and cell-free supernatants. The primers, which were tested against reference viruses from all three classes and two subclasses and accurately identified each class present, were used to characterize the endogenous expression of MuLV-related sequences in a number of murine and mink cell lines. Two murine/murine hybridomas were shown to contain expressed retroviral sequences from all three classes. The murine cell lines SC-1, Balb/c 3T3, and NIH 3T3, were found to constitutively express sequences from many of the MuLV classes. These MuLV-related sequences were not expressed in the Mus dunni or mink lung cell lines. When these primers were used in a quantitative PCR assay to determine the retroviral content of hybridoma supernatants, the values were less variable than those obtained by transmission electron microscopy (TEM). This assay can be adapted to detect and quantitate any viral contaminant in cell culture supernatants, ascites fluids, process validation samples, and final products.

Transcriptional analysis of the bovine herpesvirus 1 Cooper isolate. Temporal analysis and characterization of immediate-early, early, and late RNA.

Blot hybridization analysis of infected bovine herpesvirus 1 (BHV-1) cellular RNA isolated at various times post infection and after treatment with specific metabolic inhibitors was used to characterize transcription of the BHV-1 Cooper isolate. Synthesis of BHV-1 RNA was detected as early as 3 h post infection and reached a maximum at six to eight hours post infection. The most transcriptionally active area of the genome was between map units 0.110 to 0.195, within the HindIII I fragment. From the entire genome a total of 59 transcripts ranging in size from approximately 0.6 to 10 kilobases were characterized as belonging to one of three distinct classes. Using the protein synthesis inhibitor cycloheximide, three immediate-early transcripts were identified as originating from the internal inverted repeat region between map units 0.734 and 0.842, corresponding to the HindIII D fragment. Using phosphonoacetic acid to prevent virus DNA synthesis by inhibition of the BHV-1 DNA polymerase, 28 early transcripts were recognized. The remaining 28 transcripts, classified as late RNA, were detected without the use of metabolic inhibitors at 6 to 8 h post infection. Transcription of early and late RNA was not restricted to any specific area of the genome. Eighty percent of the transcripts from both the HindIII A fragment, between map units 0.381 to 0.537 within the unique long segment, and the HindIII K fragment, between map units 0.840 to 0.907 of the unique short segment, were designated as belonging to the early class.

Cloning and characterization of a genomic probe for malignant catarrhal fever virus.

A genomic probe specific for malignant catarrhal fever (MCF) virus was cloned by using purified viral DNA from MCF-virus strain WCll. Restriction endonuclease analysis of the purified viral DNA was used to identify the cloned viral genomic fragment. Dot blot hybridization by use of the genomic probe (pRP-5) indicated that the probe hybridized specifically with WCll-MCF virus, as well as with one other isolate of MCF-associated herpesvirus. Hybridization also was observed to a non-MCF virus strain of bovine herpesvirus.

Evaluation of a portable measure of expired-air carbon monoxide.

There are a variety of independent methods of estimating smoking status; measurement of expired air carbon monoxide has proven to be reliable and convenient. This article describes a new, inexpensive, portable analyzer for measuring expired-air carbon monoxide --the Bedfont EC50. We have compared this analyzer with the standard instrument for measuring expired-air carbon monoxide in 138 normal subjects and found good correlation and agreement. The Bedfont was demonstrated to be better at identifying smoking status, and the relevance of this finding for classification of smokers and nonsmokers by fixed-threshold carbon monoxide levels is discussed. The features of the Bedfont EC50 are particularly appealing for field and clinical use.

Validation of a simple mechanical accelerometer (pedometer) for the estimation of walking activity.

A small (28 g) mechanical accelerometer has been tested by subjecting it to controlled bench tests consisting of repetitive vertical oscillations on two designs of test rig. The accelerometer's 3-digit display provided a cumulated score with a maximum of 99.9 units. This score was compared with an independent count of the imposed oscillations and found to be linear with time (r = 0.996) and reproducible on retest (coefficient of variation = +/- 1.5%). The sensitivity ranged from 6.2 to 7.4 units/10,000 oscillations. The response was related to the maximal applied acceleration (calculated from the amplitude and frequency of the oscillations on the assumption that they were sinusoidal) and independent of the amplitude and frequency used. The threshold maximal acceleration was less than 2 m s-2 and the response had reached a plateau at 4 m s-2. During field studies the accelerometer was firmly attached over the hip in a waistband where it responded to the vertical accelerations produced by walking. When compared with an independent count of footsteps from a heel-mounted resistance pad the accelerometer score (after calibration) was not significantly different. The mean difference was (0.29 +/- 0.67, S.D.) 10(3) "steps" in a younger group (n = 8, mean age 39 years) and (0.46 +/- 1.08, S.D.) 10(3) "steps" in an older group of women (n = 6, mean age 65 years). Scores of around 10 X 10(3) "steps" can be expected in a day in moderately active young subjects and 40 X 10(3) "steps" in a week in the elderly. Simultaneously recorded scores from both right and left hips wee not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

An investigation of data entry methods with a personal computer.

The features of three methods of data entry were investigated and a trial of them was carried out using operators with differing amounts of keyboard experience. The first method was a simple system of character entry using a word processing package, and the second and third systems were written in a commercial data base language; one was designed to possess limited intelligence, the other moderate intelligence. The amount of time and computing expertise required to set up each method increased in parallel with its sophistication. The most sophisticated method offered theoretical advantages of reduced error rates and increased keying rates but these were not realized in practice. The limited intelligence method, in which data were entered into a screen image of the record form, was fastest overall and was most popular with all users. This method together with verification by dual keying will provide a convenient, rapid, and high fidelity method of data entry. The simplest method was found to be adequate for short forms but incurred high error rates with longer forms.

The use of microcomputers for data management in a large epidemiological survey.

A data management system designed around microcomputers and commercial software packages was employed for a large epidemiological study. Management involved the tracking of subjects through several stages of the study and the generation of subject listings, personalized letters of invitation, daily worklists for the field teams, and a checklist for the laboratories. These processes were controlled using a continually updated subject data base which in final form provided the core of the management system for the collected data. Data management presented major problems because of the volume of data which were received from several sources over a period of months. A key feature to emerge was the importance of an accurate serial number on all items for which a check digit was employed. The system had a short development time and was found to be inexpensive and flexible and to cope easily with the demands made of it.

Objective measurements of customary physical activity in elderly men and women before and after retirement.

An objective method for assessing customary physical activity has been described, based on heart rate and footfall signals recorded on magnetic tape using small body-borne recorders. Computer analyses were used to obtain indices of the intensity and duration of periods of physical activity using both biosignals. Threshold values were set for each individual at a heart rate related to a standard walking speed of 4.8 km . h-1 (3 miles per hour). Four activity indices were defined in terms of time spent above this threshold and the intensity of the heart rate elevation above it, applying criteria relating to the duration of periods of activity or the concurrent activation of the walking signal. The choice and validity of these indices are discussed, and results for several groups of subjects presented. Three groups of subjects aged over 60 years were studied before and after retirement: twenty-five were steel-workers and thirty-nine were factory-workers (men and women). Rather low levels of activity were recorded. After one year of retirement the female factory workers showed a significant decrease in activity. In men this was found only after several years of retirement had elapsed.

An unsupervised "aerobics" physical training programme in middle-aged factory workers: feasibility, validation and response.

This paper describes a controlled study of the effects of an unsupervised walking-programme in 108 volunteers from among 580 middle-aged employees in a Nottingham light industrial company. Objective measurements of physical condition and of customary activity were made on four occasions at 12-week intervals. The subjects were randomly allocated to three groups and encouraged to follow a walking-programme in the first, second or third periods of the study: no activity was prescribed in the other periods. Compliance with the programme was estimated from log-cards and from a week's pedometer record. Although there were no significant differences between the changes seen in subjects following the walking-programme and those in control subjects, there were significant small improvements in physical condition and modest increases in customary activity in a) those subjects actually completing the programme, and b) the subjects measured before and after their programme, pooled without regard to the period of measurement. At least some of the increased activity is maintained for 12 weeks after the programme. The marginal changes suggest that the intensity of the training-programme as experienced by the subjects was close to the threshold for maintenance of physical condition in this age-group of workers.