Accuracy of Equations to Predict Basal Metabolic Rate in Older Women

Objective To assess the accuracy of several published equations for predicting basal metabolic rate (BMR) in older women.

Design BMR was assessed in 116 healthy, older white women, aged 60 to 82 years, on three successive mornings by indirect calorimetry. Body composition was determined by dual energy X-ray absorptiometry or hydrostatic weighing. The measured BMRs were compared with values obtained from eight published prediction equations that used solely, or in various combinations, measures of height, weight, fat-free mass, age, and menopausal status.

Statistical analyses performed The root mean squared prediction error (RMSPE) was used to determine how accurately predicted BMR matched actual BMR for each subject. In addition, regression analysis was used to evaluate accuracy of predicted BMR vs directly measured BMR.

Results Predicted mean BMR determined using all eight equations was significantly correlated to measured BMR (P=.0001), accounting for 30% to 52% of the variance of measured BMR. When analyzed by RMSPE, however, the equations of Owen et al (1986), Fredrix et al (1990), and Harris-Benedict (1919) predicted actual BMR for each subject within an average of 116 kcal/day, and the equation of Cunningham (1980) resulted in the largest prediction error at 208 kcal/day.

Applications/conclusions The regression equations of Owen et al (1986), which used body weight, Fredrix et al (1990), which used body weight and age, and Harris-Benedict (1919), which used age, weight, and height as variables, were most accurate in predicting BMR in our sample of healthy older women. J Am Diet Assoc. 1995; 95:1387-1392.     

Dynamic mutation loci: allele distributions in different populations

To assess the relative contributions of trans -acting factors (replication and repair functions) and cis -acting elements (repeat and flanking DNA composition) to the mechanism of trinucleotide repeat sequence mutation we have analysed the distribution of copy number polymorphisms at 12 loci associated with dynamic mutations in 15 populations of different ethnic origins. Genome wide instability of repeats in a particular population would be evidence of trans -acting factor instigation of the mutation process, whereas instability at a particular locus (perhaps even in several populations) would be evidence that the composition of the particular locus was the most significant factor contributing to mutation. The FRA16A locus is highly polymorphic in only the European population. Some other loci exhibit distinct distributions of alleles between different populations. Therefore sequences in the vicinity of the repeat - the cis component of a particular locus - appear(s) to be more important in the mutation mechanism than sporadic genome-wide instability induced by trans -acting factors such as the DNA mismatch repair enzymes.     

Ethnicity and myotonic dystrophy: a possible explanation for its absence in sub-Saharan Africa

The CTG trinucleotide repeat, in the myotonic dystrophy (DM) myotonin protein kinase gene, was studied by PCR analysis in a total of 246 unrelated South African Bantu-speaking Negroids, 116 San and 27 Pygmies. The size and distribution of the CTG repeat were determined and showed that the alleles ranged in length from 5 to 22 repeats. The most common CTG repeat is 5 (25% of chromosomes) in the South African Negroids but 11 (27 % of chromosomes) in the San population and 12 (22% of chromosomes) in the Pygmies. The southern African Bantu-speaking Negroids and San were found to have significantly fewer large repeat length alleles than do Caucasoid and Japanese populations. Since DM has not been observed in southern African Negroids, it is possible that the occurrence of fewer large CTG repeats in the normal range may, in part, explain this absence. It seems likely, that the rare DM mutation event postulated to have occurred on a specific chromosomal haplotype, occurred after the migration of humans from Africa.     

THE EFFECT OF OXYTOCIN INFUSION ON ADENOHYPOPHYSEAL FUNCTION IN MAN

The responses of the adenohypophyseal hormones adrenocorticotrophin (ACTH), growth hormone (GH), thyroid stimulating hormone (TSH), prolactin, luteinizing hormone (LH) and follicle stimulating hormone (FSH) to sub-maximal doses of hypothalamic releasing factors were studied in six lean male volunteers (age 23-35 years) with and without infusions of oxytocin (OXT). OXT infusion (mean plasma concentration 133.6 +/- 2.6 pmol/l) completely inhibited the plasma ACTH responses to corticotrophin releasing hormone (CRH) (saline, peak increment ACTH 1.61 +/- 0.75 pmol/l; OXT, peak increment ACTH - 0.04 +/- 0.28 pmol/l; P less than 0.05). OXT infusion had no significant effect on the GH response to growth hormone releasing hormone (GHRH), the TSH and prolactin responses to thyrotrophin releasing hormone (thyroliberin, TRH) or the LH and FSH responses to gonadotrophin releasing hormone (luteoliberin, GnRH). The data support a role for OXT in the modulation of ACTH secretion in man.     

111INDIUM-LABELLED POLYMORPHONUCLEAR LEUCOCYTE SCANS IN RHEUMATOID ARTHRITIS--AN IMPORTANT CLINICAL CAUSE OF FALSE POSITIVE RESULTS

The presence of rheumatoid arthritis in patients undergoing¹¹¹indium-labelled polymorphonuclear leucocyte scanning representsa source of possible diagnostic confusion. In such patients,the labelled cells frequently accumulate over the caecum andascending colon, despite the absence of obvious pathology ofthe large bowel. The aetiology of this effect is unknown. KEY WORDS: ¹¹¹Indium-labelled polymorphonuclear leucocytes, Rheumatoid arthritis     

Carrier detection and prenatal diagnosis by intron 22 inversion analysis of the factor VIII gene

Summary In approximately 50% of severe haemophilia A patients the mutation is present in the form of a large chromosomal disruption in the factor VIII gene; this disruption is described as an inversion. It results in the physical breakage and separation of exons 1-2 and exons 23-26 of the factor VIII gene.     

ABSENCE OF EPSTEIN–BARR VIRAL ENCODED RNA (EBER) IN PRIMARY CUTANEOUS T-CELL LYMPHOMA

Epstein-Barr virus (EBV) has been associated with various extracutaneous lymphoproliferative diseases and it has been suggested that EBV may have a similar aetiological role in cutaneous T-cell lymphoma. In this study, in situ hybridization was used to investigate the presence of EBV encoded RNAs (EBER-1 and EBER-2) in 37 biopsies from 28 cases of primary cutaneous T-cell lymphoma originating from the U.K. The results showed that EBV had no demonstrable pathogenic role in the lymphomas studied, as EBER was not detected in any case.