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Biomedical subjects

C Clifford

Publications and source records attributed to C Clifford.

At least 55 records · Page 3Linked to original sources
PubMed1990

Validation of a self-administered diet history questionnaire using multiple diet records.

The validity of a self-administered diet history questionnaire has been estimated using as the reference data the mean of three 4-day diet records collected over the year prior to the administration of the questionnaire, in 1985-1986. Subjects were women ages 45-70 years, participants in the Women's Health Trial Feasibility Study, a multi-center clinical trial in which some women were randomized to be taught to adopt and maintain a low-fat diet, while others maintained their usual diet. The questionnaire produced group mean nutrient estimates closely approximating the values obtained by three 4-day records, e.g. in the usual-diet group, 37.7% of calories from fat by both food records and by questionnaire, and in the low-fat group, 21.3% of calories from fat by food records and 23.7% of calories from fat by questionnaire. Correlations between questionnaire and diet records for per cent of calories from fat were 0.67 and 0.65 respectively in the two groups; most correlations were in the 0.5-0.6 range, and were similar to those achievable by a single 4-day food record.

Aged↗
PubMed1990

Twin children in volunteer registries: biases in parental participation and reporting.

The biases in voluntary participation by adult twins are well known but less attention has been paid to twin children where parents decide on participation and provide much of the information. Several aspects of reporting including the assessment of zygosity are compared in four large Australian data bases: 1) a nationwide compulsory (and hence representative) survey of literacy and numeracy; 2) a nationwide "Twins in School" survey of parents and teachers of twins run through Education Departments and AMBA, the parents organisation in conjunction with LaTrobe; 3) the LaTrobe Twin Study which is a longitudinal program involving frequent interactions between families and researchers, and 4) the Australian NHMRC Twin Registry which has surveyed a large sample of their families with twin children by mail. One potential bias comes when recruitment is on a continuing basis as in the LaTrobe Twin Study and the Australian Twin Registry when differences between "early" and "late" enrolling families arise. One difference between the four samples arose from parents being much more likely to contrast their twins and to report problems in one but not the other, whereas teachers' and psychologists' assessments of these same children generally reported much smaller intrapair differences. Future studies should have some common questions to provide comparative data on such biases. Key questions are proposed for this area, mainly on the perceived need for different forms of remediation, together with other recommendations about the minimal essential baseline data set for a registry.

Attitude↗
PubMed1990

Drinking and cognitive impairment: current concepts and controversies.

The study of drinking and cognitive impairment has been very popular. Over the past 15 years much work has been conducted examining the specific characteristics of alcohol-related impairment, concurrent morphological changes and the process itself. Numerous theories have been advanced and progress has been made in a number of areas. However, at the present time the area is undergoing a period of re-evaluation. it is clear that if there is an association between alcohol consumption and cognitive impairment, there are a multitude of 'other factors' which need to be controlled for, before one can maintain that observed impairment is indeed a result of alcohol consumed.

Journal Article↗
PubMed1990

The source and significance of raised serum enzymes in rheumatoid arthritis.

Hepatobiliary dysfunction in rheumatoid arthritis has been suggested on the basis of raised serum activity of alkaline phosphatase, 5-nucleotidase, lactic dehydrogenase and gamma-glutamyl transferase, but a specific pathological lesion has not been demonstrated and serum transaminases and bilirubin are almost invariably normal. This paper reports a series of studies designed to determine the tissues of origin of the enzymes and offers an alternative interpretation of the enzymological findings. The results suggest that only alkaline phosphatase originates from the liver, while lactic dehydrogenase and 5-nucleotidase originate from synovial fluid polymorphs and synovial lining cells, respectively. Serum alkaline phosphatase may be induced by inflammatory mediators such as interleukin-1 because it correlates with the acute phase response. Serum lactic dehydrogenase is an integrated measure of polymorph lysis in all joints and offers a marker of joint inflammation more specific than measures such as the ESR. Levels of serum 5-nucleotidase provide information about the activity of the synovium. Finally, because hepatic necrosis does not normally occur, the transaminases may be used to monitor drug toxicity.

5'-Nucleotidase↗
PubMed1990

Changes in food patterns during a low-fat dietary intervention in women.

The Women's Health Trial was initiated by the National Cancer Institute to study the effects of a low-fat diet on the incidence of breast cancer in women at elevated risk for the disease. The purpose of this article is to examine the specific dietary changes that 173 women made while participating in a feasibility intervention program to reduce their fat intake to approximately 20% of total calories over a 12-month period. The intervention program used group sessions to teach nutrition information and behavioral skills necessary to make a life-style dietary change. Four-day food records were collected from participants at the beginning of the study and again at 12 months. Women in the intervention group reduced their total fat intake from a mean of 76 gm (39% of total energy) to 31 gm (22% of total energy), mainly by decreasing their fat intake from milk products, red meats, and fats/oils. These women used cheddar cheese, American cheese, whole milk, butter, mayonnaise, salad dressing, bacon, and hamburgers less frequently, and used diet American cheese, low-fat cottage cheese, and skim milk more frequently. They consumed less fat in their vegetable dishes, and their total caloric intake from fruit increased slightly. In addition, the overall quality of the diets improved, since there was a 20% to 50% increase in the energy-adjusted intake of vitamins and minerals from food sources.

Aged↗
PubMed1990

A case report of demodicosis.

We report on a patient who had an excessive number of mites (Demodex folliculorum) on his eye lashes, i.e. 10 mites on eight lashes examined. A review of three previous reports suggested that one mite for every two lashes represents an over population of this nearly ubiquitous mite. Greasy scales on the lashes and foamy tears suggested that seborrhea was present as well as demodicosis. The primary symptoms of itching was relieved after one week of treatment with mercuric oxide ointment and lid scrubs, although the number of mites was not reduced. Treatment for an additional two weeks did reduce the mite number. We therefore recommend continuing treatment for demodicosis for at least three weeks even if symptoms abate sooner.

Aged↗
PubMed1990

Results of a randomized feasibility study of a low-fat diet.

A 2-year randomized clinical trial was conducted to test whether free-living women aged 45 to 69 years can reduce the fat content of their diet from the typical US level of approximately 39% to 20% of energy from fat, using readily available foods, when given nutritional and behavioral counseling and social support. Three clinical units randomized 303 selected volunteers into intervention (low-fat eating plan) or control (customary diet) groups. The two groups were comparable at baseline. The intervention group received nutrition instruction and behavioral counseling largely in permanent groups of 12 to 15 participants meeting weekly, then biweekly, and finally monthly. At 6 months, they had substantially reduced the mean proportion of total energy from fat from 39.1% to 20.9%, compared with the control group's nonsignificant reduction from 39.0% to 38.1%. At 12 and 24 months, they sustained the reduction of energy from fat. Weight loss and plasma cholesterol level changes in the intervention group supported the self-recorded dietary intake changes. Attendance at intervention sessions averaged 75% during the first 6 months and, subsequently, 60% to 70%. Four-day food records for the randomized women were obtained at 6 and 12 months from approximately 95% and at 24 months from 87%. A clinical trial of a low-fat diet is feasible in women.

Aged↗
PubMed1989

In vitro comparison of quantitative computed tomography and broadband ultrasonic attenuation of trabecular bone.

In vitro measurements of os calces and trabecular bone samples have been carried out using broadband ultrasonic attenuation (BUA) and quantitative computed tomography (QCT). The correlation between the measurements was 0.92 and 0.86 for the heelbones and the trabecular samples respectively, and the QCT and BUA correlated equally well with the physical density of the samples, indicating that the new ultrasonic technique is potentially useful for the evaluation of trabecular bone for the diagnosis of osteoporosis.

Adult↗
PubMed1988

Statistical design of the Women's Health Trial.

The National Cancer Institute has initiated a randomized trial to determine whether a low fat diet can reduce the incidence of breast cancer among women at increased risk for this disease. A feasibility trial involving 303 women has been conducted to examine recruitment strategies, study short-term compliance and, more generally, develop and refine trial procedures. The feasibility trial group also developed a detailed full-scale trial design plan, and randomization of participants to such a trial is currently underway. The purpose of this report is to describe the major design features of this Women's Health Trial, with particular emphasis on the statistical aspects of the design. The trial is planned to last 10 years and to include 32,000 participants. Of these 32,000 women, 12,800 will be assigned to a low fat diet intervention, and the other 19,200 will constitute a control group. The sample size of 32,000 arises from a range of estimates and assumptions pertaining to (a) the incidence of breast cancer at enrollment corresponding to selected eligibility criteria, (b) the relative risk of breast cancer as a function of a woman's history of dietary fat intake, (c) compliance assumptions in terms of average percent fat in the intervention and control groups as a function of time from randomization, and (d) rates of competing causes of death. These estimates and assumptions will be discussed, as will the robustness of the intended sample sizes to departures from such design assumptions.

Aged↗
PubMed1984

The genetic basis of cerebral ventricular volume.

Cerebral ventricular volume, assessed by computed tomography, is a genetically determined trait. In a series of 18 monozygotic and 18 dizygotic twins, heritability values ranged from 82% to 85% depending on the method of calculation.

Adult↗
PubMed1983

Current genetic and biological approaches to alcoholism.

Three out of 4 adoption and 2 out of 3 twin studies imply a genetic contribution to alcoholism in males. A recent study of moderate drinking in male twins suggests that familial factors account for some two-thirds of the variance in alcohol consumption, and that the genetic component slightly outweighs the effects of the within family culture. There has been little support for the notion of a genetic entity which expresses itself as alcoholism in males and depressive illness in females, but among normal male twins anxiety and depression are genetically correlated with alcohol consumption. Increased liability to form acetaldehyde and the potentially additive tetrahydroisoquinolines could be one factor predisposing to alcoholism but human studies have been less convincing than their animal counterparts.

Alcohol Drinking↗
PubMed1982

Communicable disease associated with milk and dairy products in England and Wales 1951-80.

In England and Wales between 1951 and 1980 233 reported outbreaks of communicable disease attributed to milk or dairy products affected nearly 10 000 people, of whom four died. Tuberculosis and brucellosis have been controlled, but milk-borne outbreaks of salmonellosis and campylobacter enteritis due to raw or defectively pasteurised milk are common and may be increasing in number. Universal heat treatment of milk is an effective preventive measure, and it is regrettable that the continued sale of untreated milk is to be permitted in England and Wales.

Animals↗