Computer-aided diagnosis: development of automated schemes for quantitative analysis of radiographic images.

Preliminary results obtained with computer-aided diagnosis (CAD) from various radiographic examinations are very encouraging. However, CAD is still at an early stage of its development. It will be necessary to increase further the understanding of image features of normal and abnormal patterns, to establish databases, and to devise specific approaches for particular types of pathology. Although the existing schemes are designed to be applied to digital radiographs, similar techniques can be applied in the future to cross-sectional images such as CT, MRI, and ultrasound. We believe that CAD will become clinically practical in the near future.     

Ispaghula husk in the treatment of hypercholesterolaemia: a double-blind controlled study

BACKGROUND: Lowering cholesterol levels by natural dietary modification is an attractive first-line option for the treatment of mild-to-moderate hypercholesterolaemia. However, results have been less than impressive. The addition of soluble fibre - for example, psyllium or oat bran - to a modified diet has produced better results. In this study, the cholesterol-level-lowering effect of ispaghula husk and dietary advice was compared with placebo and dietary advice in treating patients with mild-to-moderate hypercholesterolaemia. METHODS: The double-blind, placebo-controlled, randomized comparison was conducted in 42 general practices and three hospital centres in the UK. There was an initial 8-week diet-only period and then a 1 2-week treatment period. Ispaghula treatment (7.0 or 10.5 g/day) was continued for a further 12 weeks for some patients. A total of 340 patients, aged 18 to 65, with mild-to-moderate hypercholesterolaemia [low-density lipoprotein (LDL) cholesterol levels of 4.1 mmol/l or more] entered the 12-week treatment phase. Levels of LDL cholesterol, total cholesterol, high-density lipoprotein cholesterol, triglycerides and apolipoproteins A1 and B were determined. RESULTS: LDL cholesterol and total cholesterol levels fell during the diet-only period. In members of the intention-to-treat population after the 8-week diet period, LDL cholesterol levels had fallen by 0.42 mmol/l (8.7%) for the 7.0 g ispaghula/day group after 12 weeks of treatment, whereas LDL cholesterol levels had fallen by 0.48 mmol/l (9.7%) for the 10.5 g ispaghula/day group. Ispaghula at both doses produced significantly greater reductions in LDL cholesterol levels than did placebo (7.0 g/day versus placebo, P=0.009; 10.5 g/day versus placebo, P<0.001). Ispaghula and modification of diet together reduced LDL cholesterol levels by 10.6-13.2% and total cholesterol levels by 7.7-8.9% during the 6-month period. CONCLUSIONS: Ispaghula husk as an adjunct to diet is effective and well tolerated in the management of appropriate patients with mild-to-moderate primary hypercholesterolaemia.     

Implicit sequence learning processes after unilateral stroke

Implicit learning is durable over time, robust under psychological stress and shows specificity of transfer; characteristics that may be beneficial in stroke rehabilitation. The purpose of this study was to investigate implicit sequence learning processes in unilateral stroke using an extended number of trial blocks in a serial reaction time task (SRTT). Previous research, using a SRTT, has produced equivocal results that may be associated with the small number of trial blocks used. Seven adults, at least one year after stroke, and eight controls performed 54 blocks of a modified SRTT over two weeks. Participants responded with a finger key press during acquisition and retention and with a whole arm movement during transfer. Response times in milliseconds were used to measure learning. The stroke group performed more slowly than the controls during all experimental phases. Response times for both groups decreased with practice of the repeating sequence, increased with introduction of a random sequence, and decreased when reintroduced to the repeating sequence of the SRTT. Both groups demonstrated delayed retention of knowledge of the sequence over a two-week period and exhibited specificity of transfer. These data suggest that with extended practice people with unilateral stroke are able to learn implicitly.     

Blood pressure-dependent and independent effects of agents that inhibit the renin-angiotensin system

OBJECTIVES: To evaluate the blood pressure-dependent and independent effects of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) on major cardiovascular events. METHODS: Using data from 26 large-scale trials comparing an ACEI or an ARB with placebo or another drug class, meta-regression analyses were conducted in which treatment-specific relative risks for major cause-specific outcomes [stroke, major coronary heart disease (CHD) events and heart failure] were regressed against follow-up blood pressure differences. RESULTS: From a total of 146 838 individuals with high blood pressure or an elevated risk of cardiovascular disease, 22 666 major cardiovascular events were documented during follow-up. The analyses showed comparable blood pressure-dependent reductions in risk with ACEI and ARB (P >or= 0.3 for all three outcomes). The analyses also showed that ACEI produced a blood pressure-independent reduction in the relative risk of CHD of approximately 9% (95% confidence interval 3-14%). No similar effect was detected for ARB, and there was some evidence of a difference between ACEI and ARB in this regard (P = 0.002). For both stroke and heart failure there was no evidence of any blood pressure-independent effects of either ACEI or ARB. CONCLUSION: There are similar blood pressure-dependent effects of ACEI and ARB for the risks of stroke, CHD and heart failure. For ACEI, but not ARB, there is evidence of blood pressure-independent effects on the risk of major coronary disease events.     

Social comparison and depression: people with mild and moderate intellectual disabilities

There has been limited research on the role of sociocognitive factors in depression with people who have a mild intellectual disability. However, an association has been found between negative social comparison and depressed mood. We extend previous work by including individuals with clinical depression. A between-groups design of 18 depressed versus 18 nondepressed participants was used. Depression measures were administered, along with measures of self-esteem and social comparison. Participants reported the salience of the social comparisons they made. Depressed participants reported significantly more negative social comparisons; the nondepressed group reported that the positive comparisons they made were more salient. These results have implications for cognitive behavior interventions and the possibility of working with people in the context of their interpersonal beliefs.     

Obesity, serum cholesterol, and estrogens in premenopausal women

Creatinine-adjusted levels of estrone, estradiol, and estriol were determined in luteal phase urine specimens of 200 premenopausal women from rural areas of Greece. The relation of each estrogen to height, weight, obesity index, and serum cholesterol was studied by multiple regression, controlling for age, age at menarche, and ovulation status (ovulation, anovulation, undetermined). No consistent relation between any of the somatometric variables and any of the urine estrogens emerged from the statistical analysis, but among older women (30-40 years old) both estrone and estradiol were positively associated with serum cholesterol (p less than 0.05). The data provide no support for the hypothesis that the relationship between body weight and breast cancer risk is mediated through an influence of body weight on estrogen levels--at least in premenopausal women. On the other hand the data on serum cholesterol levels are consonant with the idea that qualitative aspects of nutrition may affect breast cancer risk among older (e.g., postmenopausal) women.     

Age at first birth and breast cancer risk

An international collaborative study of breast cancer and reproductive experience has been carried out in 7 areas of the world. In all areas studied, a striking relation between age at first birth and breast cancer risk was observed. It is estimated that women having their first child when aged under 18 years have only about one-third the breast cancer risk of those whose first birth is delayed until the age of 35 years or more. Births after the first, even if they occur at an early age, have no, or very little, protective effect. The reduced risk of breast cancer in women having their first child at an early age explains the previously observed inverse relationship between total parity and breast cancer risk, since women having their first birth early tend to become ultimately of high parity. The association with age at first birth requires different kinds of etiological hypotheses from those that have been invoked in the past to explain the association between breast cancer risk and reproductive experience.     

Pulmonary nodules: computer-aided detection in digital chest images

Currently, radiologists fail to detect pulmonary nodules in up to 30% of cases with actually positive findings. Diagnoses may be missed due to camouflaging effects of anatomic background, subjective and varying decision criteria, or distractions in clinical situations. We developed a computerized method to detect locations of lung nodules in digital chest images. The method is based on a difference-image approach and feature-extraction techniques, including growth, slope, and profile tests. Computer results were used to alert 12 radiologists to possible nodule locations in 60 clinical cases. Preliminary results suggest that computer aid can improve the detection performance of radiologists.