The Tromso Family Intervention study: Effects of a family approach to reduce coronary risk factors in children of high-risk men

This study was done to assess the effect of intervention oncoronary heart disease risk factors among children using a familyapproach. Men at increased risk of coronary heart disease (n=l,373)were randomly allocated to intervention and control groups togetherwith their wives (n=1,143) and children (n=2,838). The interventionfamilies received home visits by a physician and dietician,quarterly newsletters regarding diet, smoking and physical exerciseand were invited to ‘stop smoking’ clinics and meetingson nutrition and exercise. At rescreening 6 years later, 29of the control children exceeded pre-set risk factor limitscompared with 15 in the intervention group (p<0.05). Childrenin the intervention group reported 'better' dietary habits thanchildren in control families, especially for foods commonlyeaten at home. At least 7 of the 9 ‘good’ dietaryhabits were practised by 205 intervention children comparedwith 156 in the control group (p<0.01) and 88 versus 154reported practising at least 3 of the 9 listed ‘bad’dietary habits (p<0.001). No significant differences werefound between the 12–24 year old children in the 2 groupsin mean risk factor levels, the proportion of smokers or inthe pattern of physical exercise. It was concluded that coronaryheart disease risk reduction in children using the family approachis well received and results in dietary changes and a reducednumber exceeding pre-set risk factor limits. The effect on meanrisk factor levels, smoking and physical exercise was small.Targeting the intervention more directly to children could possiblyimprove the results. Also, life-style changes may require alonger follow-up before significant differences can be seenamong teenagers.     

REPORT FROM THE HLA CLASS II TYPING BY PCR-SSP MULTICENTRE STUDY

Results from 360 HLA-DR and -DQ ‘low-resolution’ typings with polymerase chain reaction sequence-specific primers (PCR-SSP), performed by nine laboratories, were analysed for their overall utility in routinely defining the HLA-DR1–DR18, DR51–DR53 and DQ1–DQ9 specificities in less than 2.5 h. Thirty EDTA blood samples and 10 DNA samples were distributed and analysed by each laboratory. DNA was extracted using a rapid bromide salt extraction protocol. Complete HLA-DR and -DQ typings were performed, three by three, on pre-aliquoted 96-tube PCR trays. When compared with reference typing, 351/360 (98%) correct DR typings were obtained, whereas 320/360 (89%) of the DQ phenotypes were correctly assigned. The time for three complete HLA-DR and -DQ ‘low-resolution’ typings, including DNA extraction, ranged from 2.0 h to 2.3 h. Unfortunately, an unusually high level of PCR amplification failures was observed (3%), probably due to diffusion and a significant volume loss from some of the pre-aliquoted primer mixes. Consequently, only 52% of the typings were without any amplification failure, and 0–2 amplification failures where found in 88% of the PCR-SSP typings performed. The number of HLA-DR–DQ retypings needed was 7 and 8%, respectively, reflecting the low number of typings where allelic identification was directly affected by the relatively high level of amplification failures in this study. Thus, a 91–98% success rate of correctly identified HLA-DR and -DQ alleles could be maintained, even under suboptimal typing conditions.     

A double-blind multiple crossover trial evaluating a transdermal nitroglycerin system vs placebo

Fifty-six patients with angina pectoris on effort participatedin a 28-day study comparing a transdermal nitroglycerin system(TNS) against placebo. The protocol was based on a regular double-blindmulti-crossover pattern. The variables recorded included dailysublingual nitroglycerin requirement, daily anginal attack frequency,and a subjective patient evaluation of each day on a visualanalog scale. TNS dosage ranged from 10 cm² (5 mg per 24 h)to 60 cm² (30 mg per 24 h) based on the patient's dosage priorto commencement of the study. All other medication was continuedunchanged. The results demonstrate improvement on active therapyin the patient group using 20 cm² TNS whereas no significantimprovement in patients using 10 cm² TNS was seen. In the higherdose group, the mean number of daily anginal attacks was 2.5on placebo and 1.4 on active therapy (P<0.0001). Correspondingmean daily sublingual nitroglycerin requirement was 3.6 on placeboand 2.3 on active therapy (P<0.0001). Although TNS therapywas associated with significant improvement in the group usingthe higher dosage, the results suggest the development of toleranceon active therapy. The possibility of rebound effect and theabsence of demonstrable efficacy in the low dose group requirefurther investigation.