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Observational assessments of parent-adolescent conflict can guide interventions to prevent and reduce conflict and mental health problems. The authors identified the Observing Mediational Interactions (OMI) as a particularly useful coding system for examining parent-adolescent conflict. The OMI is the observational measure used in the Mediational Intervention for Sensitizing Caregivers (MISC) and quantifies emotional (attachment-based) and cognitive (learning-based) behaviors during caregiver-child interactions.

Increased dietary intake of alpha-linolenic acid (ALA) may be desirable to enrich tissue eicosapentaenoic acid (EPA; 20:5n-3) but competition between n-3 and n-6 fatty acids for enzymes involved in elongation and subsequent acylation will determine the relative proportions of phospholipid fatty acids. The aim of the present study was to examine the effects of altering the dietary ALA:linoleic acid (LA) ratio on rat platelet EPA and arachidonic acid (AA; 20:4n-6) concentrations. Sprague-Dawley rats were fed on diets containing 30% total energy as fat with approximately 10% each of saturated, monounsaturated and polyunsaturated fatty acids with one of the following ALA:LA values; 1:7, 1:4, 1:1 or 1.3:1 (nine rats per group). After 4 weeks, blood was withdrawn from the abdominal aorta and platelet fatty acids analysed. The proportion of EPA was greater at the 1:1 and 1.3:1 ratios compared with the 1:7 and 1:4 (P < 0.05), and a decrease in AA was observed (P < 0.05) at the higher ratios. It was established that the platelet EPA:AA value increased (P < 0.05) as the dietary ALA:LA value increased.

Objective: To compare the effects of supplementing a low fat diet with an alpha-linolenic acid-rich (C18:3 n-3) oil with a linoleic acid-rich (C18:2 n-6) oil on platelet composition and function., Design: Prospective study with random allocation to one of the two oils., Setting: Free-living study., Subjects: Eleven healthy young males recruited from within the University., Interventions: Subjects were allocated to consume 40 g of either flaxseed oil (n = 5) or sunflowerseed oil (n = 6) daily for 23 days. Fasting blood samples were collected at commencement and completion of supplementation for analysis of platelet fatty acids and platelet aggregation., Results: The platelet eicosapentaenoic acid (EPA) more than doubled in the group taking flaxseed oil (P < 0.05) but was unchanged in the sunflowerseed group. As a result the platelet EPA:arachidonic acid ratio, considered a marker for thromboxane production and platelet aggregation potential, increased in the flaxseed group (P < 0.05). The aggregation response induced by 0.75 and 2 micrograms of collagen was decreased in those taking flaxseed oil (P < 0.05)., Conclusion: This study provides further evidence that consumption of alpha-linolenic acid-rich oils may offer protective effects against cardiovascular disease over linoleic acid-rich oils via their ability to decrease the tendency of platelets to aggregate.

Plasma pyridoxal-5'-phosphate (PL-5'-P), pyridoxal (PL), pyridoxine (PN), and 4-pyridoxic acid (4-PA) were measured by high-performance liquid chromatography (HPLC) in 39 patients (15 male, 24 female) with chronic fenal failure undergoing regular haemodialysis and 46 healthy controls (28 male, 18 female). All three vitamers of vitamin B6 and the metabolite were significantly elevated in the haemodialysis patients. Mean PL-5'-P and PN concentrations were 20 times the mean in controls. Only one patient took a vitamin B6 supplement. In view of the neurotoxicity of supranutritional intakes of PN in normal humans we suggest that supplements of PN be carefully monitored when administered to patients with chronic renal failure.

The total body protein status of 18 patients undergoing regular haemodialysis was assessed by measuring total body nitrogen (TBN) using in vivo neutron activation analysis (NAA). Eighteen healthy controls, who were selected according to their height, age and sex match with the patients were also measured. The male and female patients were both found to have lower mean values for total body protein (P less than 0.01, P less than 0.025 respectively) although they had similar weights compared with their matched controls. Seven patients were measured on further occasions and only two patients showed a change in their body protein. One female showed an increase of 11 per cent in body protein (with an increase of 25 per cent in body weight) after intensive nutritional repletion therapy. In vivo NAA provides a direct means of measuring body protein and is a reliable method to monitor changes with treatment regimes.

In order to assess the necessity of vitamin supplementation for patients who are receiving haemodialysis, measurements of vitamin status were made, and both dietary and supplementary intakes were assessed, in 26 patients who were undergoing haemodialysis. Blood samples were collected from these patients before they underwent haemodialysis, after an overnight fast, for the measurement of plasma retinol, alpha-tocopherol and ascorbate levels. Serum and erythrocyte folate levels were measured also. Thiamin status was assessed by the effect of added thiamin pyrophosphate on erythrocyte transketolase activity and pyridoxine status was assessed by the effect of added pyridoxal-5'-phosphate on erythrocyte aminotransferase activity. All patients had elevated plasma retinol levels; 48% of patients had elevated plasma alpha-tocopherol levels; the plasma ascorbate level was low in 50% of patients but was elevated in 25% of patients; and plasma and erythrocyte folate levels were elevated in 76% and 91% of patients, respectively. Thiamin status was normal in all but one patient and the pyridoxine level appeared to be low in two other patients. Many patients had low dietary intakes of vitamin C, folate and vitamin B6. We conclude that supplements of vitamins A and E are not required and, when dietary intakes of water-soluble vitamins are marginal, these should be supplemented at a dose as near as possible to the recommended dietary intake.