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Biomedical subjects

C Heath

Publications and source records attributed to C Heath.

At least 37 records · Page 2Linked to original sources

Prospective study of intentional weight loss and mortality in never-smoking overweight US white women aged 40-64 years.

Although 40% of US women indicate they are currently trying to lose weight, the association between intentional weight loss and longevity is unknown. The authors analyzed prospective data from 43,457 overweight, never-smoking US white women aged 40-64 years who in 1959-1960 completed a questionnaire that included questions on weight change direction, amount, time interval, and intentionality. Vital status was determined in 1972. Proportional hazards regression was used to estimate mortality rate ratios for women who intentionally lost weight compared with women who had no change in weight. Women who died within the first 3 years of follow-up were excluded. Analyses were stratified by preexisting illness and adjusted for age, beginning body mass index, alcohol intake, education, physical activity, and health conditions. In women with obesity-related health conditions (n = 15,069), intentional weight loss of any amount was associated with a 20% reduction in all-cause mortality, primarily due to a 40-50% reduction in mortality from obesity-related cancers; diabetes-associated mortality was also reduced by 30-40% in those who intentionally lost weight. In women with no preexisting illness (n = 28,388), intentional weight loss of > or = 20 lb (> or = 9.1 kg) that occurred within the previous year was associated with about a 25% reduction in all-cause, cardiovascular, and cancer mortality; however, loss of < 20 lb (< 9.1 kg) or loss that occurred over an interval of > or = 1 year was generally associated with small to modest increases in mortality. The association between intentional weight loss and longevity in middle-aged overweight women appears to depend on their health status. Intentional weight loss among women with obesity-related conditions is generally associated with decreased premature mortality, whereas among women with no preexisting illness, the association is equivocal.

Adult↗

How do desk-top computers affect the doctor-patient interaction?

General practice consultations were video-recorded before and after the introduction of a desk-top computer system into the practice. The recordings were analysed by detailed qualitative scrutiny of tape and transcripts (conversation analysis) to discover regular patterns of interaction. This analysis confirmed that the introduction of computers into the consultation had a significant impact on the communication between patient and doctor. In particular, we found that computer technology has had an impact on the practitioners' conduct and on the disclosure of information by the patient. The analysis also points to some recommendations both for training general practitioners in the use of computerized systems in the consultation, and for the (re)design of the technologies themselves.

Computer Terminals↗

Do family physicians treat obese patients?

BACKGROUND: The purpose of this study was to characterize what patient and physician factors increase the likelihood of physicians counseling weight loss in their overweight patients. METHODS: A retrospective chart survey of 418 outpatient charts from 50 family medicine residents and faculty was conducted. RESULTS: Of the 267 patients who were overweight based on a body mass index score of more than 27, only 29.6% had been instructed to lose weight. Overweight patients with hypertension, diabetes, hypercholesterolemia, or coronary artery disease were instructed to lose weight 32.9% of the time. Patient age or sex and physician age, sex, or level of training did not affect the frequency of treatment. CONCLUSION: Physicians need to be more aggressive in their counseling of overweight patients.

Adult↗

Mortality from tobacco in developed countries: indirect estimation from national vital statistics.

Prolonged cigarette smoking causes even more deaths from other diseases than from lung cancer. In developed countries, the absolute age-sex-specific lung cancer rates can be used to indicate the approximate proportions due to tobacco of deaths not only from lung cancer itself but also, indirectly, from vascular disease and from various other categories of disease. Even in the absence of direct information on smoking histories, therefore, national mortality from tobacco can be estimated approximately just from the disease mortality statistics that are available from all major developed countries for about 1985 (and for 1975 and so, by extrapolation, for 1995). The relation between the absolute excess of lung cancer and the proportional excess of other diseases can only be approximate, and so as not to overestimate the effects of tobacco it has been taken to be only half that suggested by a recent large prospective study of smoking and death among one million Americans. Application of such methods indicates that, in developed countries alone, annual deaths from smoking number about 0.9 million in 1965, 1.3 million in 1975, 1.7 million in 1985, and 2.1 million in 1995 (and hence about 21 million in the decade 1990-99: 5-6 million European Community, 5-6 million USA, 5 million former USSR, 3 million Eastern and other Europe, and 2 million elsewhere, [ie, Australia, Canada, Japan, and New Zealand]). More than half these deaths will be at 35-69 years of age: during the 1990s tobacco will in developed countries cause about 30% of all deaths at 35-69 (making it the largest single cause of premature death) plus about 14% of all at older ages. Those killed at older ages are on average already almost 80 years old, however, and might have died soon anyway, but those killed by tobacco at 35-69 lose an average of about 23 years of life. At present just under 20% of all deaths in developed countries are attributed to tobacco, but this percentage is still rising, suggesting that on current smoking patterns just over 20% of those now living in developed countries will eventually be killed by tobacco (ie, about a quarter of a billion, out of a current total population of just under one and a quarter billion).

Adult↗

Methods for increasing monoclonal antibody production in suspension and entrapped cell cultures: biochemical and flow cytometric analysis as a function of medium serum content.

The growth and antibody production of the SP2/0-derived hybridoma HB124 (ATCC) grown in media containing varying amounts of fetal bovine serum (FBS) were monitored using biochemical and flow cytometric methods. Hybridomas grown in 100 ml spinner flasks with RPMI-1640 containing varying amounts of serum demonstrated that cell growth, viability and IgG production show significant changes when serum content is decreased from 10.0 to 5.5 to 1.0 and 0.5%. A longer lag phase resulted when the lower serum content media were used. Cellular rates of glucose uptake showed a significant increase as serum levels were lowered. Similarly, exponential phase IgG production rates increased as the amount of serum was decreased, probably as a result of the decreased rate of exponential growth. Flow cytometric analysis showed a similar increase in cellular IgG content as medium serum levels declined. In contrast, the maximum IgG concentrations were found in flasks containing 1% FBS or above with the lowest concentration in the 0.5% FBS flask being due to the lower numbers of viable cells. Cells grown in microporous hollow fiber reactors were fed with medium containing serum which was decreased stepwise with time. Decreasing medium serum content stepwise from 10 to 2.5% resulted in increased antibody production. However, complete removal of serum from the medium resulted in a significant drop in antibody productivity. Cumulative antibody production was equivalent for cells grown entirely in medium containing 10% FBS and for those which experienced a drop to 2.5% FBS. To compare a defined serum-free medium preparation with medium containing 10% FBS, cells were again grown in batch suspension culture and analyzed. The growth rates were similar but there was a significant difference in IgG production rates. The serum-free culture exhibited both higher cellular production rates and higher IgG concentrations. These results indicate that decreasing medium serum content can adversely affect antibody yield because of lower cell viabilities, not because of lower production rates. Use of a defined serum-free medium, as done in this study, results in higher yields because of a higher IgG production rate as well as good cell growth and viability.

Animals↗

Diagnosis of patellofemoral pain syndrome.

This syndrome, also known as chondromalacia patellae, is characterised by pain and crepitus around the patella during activities that require flexion of the knee under loading, for example, climbing stairs.

Femur↗

What is a good GP?

Explore the source record for details and available documents.

Communication↗

Specific stimulation of simian virus 40 late transcription in vitro by a cellular factor binding the simian virus 40 21-base-pair repeat promoter element.

We have identified a cellular transcription factor from uninfected HeLa cells that stimulates the simian virus 40 (SV40) late mode of transcription and specifically binds the SV40 21-base-pair repeat promoter element. In particular, the late SV40 transcription factor (LSF) stimulates transcription at initiation sites L325 and L264 of the SV40 late promoter, which are the major transcription sites utilized after DNA replication during the SV40 lytic cycle. In addition, LSF appears to stimulate transcription to a lesser extent from the late-early initiation site of the early promoter. LSF binds specifically to the 21-base-pair repeats of the SV40 promoters, forming specific protein-DNA complexes, which migrate more rapidly through nondenaturing polyacrylamide gels than that formed by the previously identified transcription factor Sp1. Thus, LSF is distinguishable from Sp1 in both its transcriptional and DNA-binding properties. These findings suggest a potential role of LSF in the early to late transcriptional switch during a SV40 lytic infection.

Binding Sites↗

Transcription directed by the HIV long terminal repeat in vitro.

The long terminal repeat (LTR) of the AIDS virus (HIV) has been found to contain promoter sequences that are active in uninfected HeLa whole cell and nuclear extracts. Here we report that elements upstream of position -104 (start site +1) do not affect transcriptional activity in vitro whereas sequences between -104 and -57 are required for such activity. Using a reconstituted RNA polymerase II system, we demonstrate that a partially purified fraction containing Spl not only stimulates, as was previously reported, but is required for accurate initiation of transcription directed by the HIV LTR. In addition, based on a computerized analysis, we report the presence of a region in the HIV LTR (positions -151 to -80) that is similar to the 72 base pair enhancer element of SV40 and that includes a highly conserved segment also present in the cytomegalovirus enhancer. Moreover, the HIV and HTLV-I LTRs are shown to share a region of similarity that includes the 21 base pair motif found in the enhancers of the human and bovine T-lymphotropic viruses. The R region of the HIV LTR is found to have two extensive regions of dyad symmetry rather than one as was previously reported. The significance of these observations for HIV pathogenesis is discussed.

DNA Restriction Enzymes↗

First-trimester fetal diagnosis for haemoglobinopathies: report on 200 cases.

First-trimester prenatal diagnosis by DNA analysis was found to be possible in 224 (80%) of 281 families at risk of having a child with beta-thalassaemia major. 200 prenatal diagnoses, mainly for beta-thalassaemia or sickle-cell anaemia, were made by means of chorionic villus sampling and fetal DNA analysis. The overall fetal loss rate was 6.7%, the majority being in the first half of the programme. There was one misdiagnosis. Prenatal diagnosis was also carried out successfully for both pairs of twins in two pregnancies. Comparison of these results with 53 prenatal diagnoses made with DNA prepared from amniotic fluid suggests that the first-trimester procedure is more reliable. If further experience confirms that chorionic villus sampling has an acceptably low risk for both mother and fetus it will largely replace other methods for prenatal diagnosis of the haemoglobin disorders and other single-gene conditions.

Amniotic Fluid↗

Meiotic recombination between two polymorphic restriction sites within the beta globin gene cluster.

Analysis of beta globin gene haplotypes for prenatal diagnosis of beta thalassaemia has revealed a recombination event within the beta globin gene cluster. Both a change in the AvaII polymorphic site within the beta globin gene and a change in the phenotype of the beta globin gene were observed. Paternity was established by the pedigree analysis of hypervariable 'minisatellite' DNA polymorphisms and the most probable explanation of the recombination event is a crossover between the psi beta globin gene and the beta globin gene. The data provide direct evidence in support of a DNA region 3' to the beta globin gene with a recombination frequency much higher than expected, and have important implications for the prenatal diagnosis of beta thalassaemia by linked restriction fragment length polymorphisms.

Alleles↗

Participation in the medical consultation: the co-ordination of verbal and nonverbal behavior between the doctor and patient.

The following paper is concerned with the coordination of verbal and nonverbal behaviour by the doctor and patient in the medical consultation. It explores the relationship between the talk of the patient and the nonverbal behaviour of the doctor and demonstrates how the gaze direction of the doctor plays a crucial part in the articulation of an utterance by the patient. In examining a series of examples drawn from primary health care consultations, the analysis reveals how patients, or more generally speakers, use gestural activity to realign the gaze of their recipient(s) and encourage their participation in talk. In this fashion the paper addresses the problem of how the participants maintain a state of mutual involvement and sustain their integration within social interaction.

Behavior↗

A study of dust-induced lymphocyte blastogenesis.

The in vitro measurement of dust allergen-stimulated lymphocyte blastogenesis by the incorporation of H3-thymidine can be a useful measurement for the evaluation of the cellular immune function in dust allergy patients. Dust allergy patients receiving immunotherapy had lower lymphocyte responses than those not receiving immunotherapy. Additionally, dust allergy patients as a whole showed higher lymphocyte stimulation indices than normal control.

Allergens↗