Hunter-gatherers as models in public health

Hunter-gatherer populations are remarkable for their excellent metabolic and cardiovascular health and thus are often used as models in public health, in an effort to understand the root, evolutionary causes of non-communicable diseases. Here, we review recent work on health, activity, energetics and diet among hunter-gatherers and other small-scale societies (e.g. subsistence farmers, horticulturalists and pastoralists), as well as recent fossil and archaeological discoveries, to provide a more comprehensive perspective on lifestyle and health in these populations. We supplement these analyses with new data from the Hadza, a hunter-gatherer population in northern Tanzania. Longevity among small-scale populations approaches that of industrialized populations, and metabolic and cardiovascular disease are rare. Obesity prevalence is very low (<5%), and mean body fat percentage is modest (women: 24-28%, men: 9-18%). Activity levels are high, exceeding 100 min d^-1 of moderate and vigorous physical activity, but daily energy expenditures are similar to industrialized populations. Diets in hunter-gatherer and other small-scale societies tend to be less energy dense and richer in fibre and micronutrients than modern diets but are not invariably low carbohydrate as sometimes argued. A more integrative understanding of hunter-gatherer health and lifestyle, including elements beyond diet and activity, will improve public health efforts in industrialized populations.

Cognitive exposure versus avoidance in patients with chronic pain: adherence matters

BACKGROUND

Behavioural exposure methods can reduce pain-avoidance behaviours, but outcomes vary. One possible explanation is that patients employ cognitive (experiential) avoidance during behavioural exposure. If so, reducing cognitive avoidance during behavioural exposure should help. One option is interoceptive exposure (IE), which involves sustained exposure (via attention) to pain sensations. In order to test if IE could improve outcomes from behavioural exposure, this study with mixed chronic pain patients compared outcomes from a cognitive behavioural therapy (CBT) pain management programme incorporating either IE or distraction from pain.

METHODS

One hundred forty chronic pain patients were randomly assigned to CBT + IE or CBT + distraction. Outcome measures included pain, disability, depression and medication. Measures reflecting degree of threat of pain were also employed (catastrophizing, fear-avoidance, pain self-efficacy and pain acceptance). An intention-to-treat approach, using mixed-effects model repeated measures, as well as conventional inferential statistical tests, effect sizes and reliable change indices were employed to evaluate the outcomes up to 1-year post-treatment.

RESULTS

Significant improvements were achieved by both treatment conditions on all outcome measures and on measures reflecting the threatening nature of pain, with no differences between treatment conditions.

CONCLUSIONS

The addition of IE to behavioural exposure did not improve outcomes. However, higher adherence to either attentional strategy was associated with larger effect sizes on all measures, suggesting factors shared by the two treatments could have contributed to the outcomes. Taken as a whole, the results suggest that increasing adherence to treatment strategies, possibly by motivational measures, would improve the overall outcomes of these interventions.

Use of telehealth technology to extend child protection team services

OBJECTIVE

In response to increased referrals to Florida's Child Protection Teams and concern regarding statewide availability of medical expertise in the area of child abuse and neglect, Children's Medical Services of the Florida Department of Health established a telemedicine project to facilitate immediate expert medical evaluations of alleged child abuse or neglect. This article describes a baseline examination of the project, including the technique of concept mapping, to examine how larger systematic factors influence the adaptation of telemedicine technology in child abuse examination settings.

METHODS

This study included interviews of key staff plus the incorporation of concept mapping, which takes qualitative data (individual statements and opinions) and quantifies them (sorts and ranks them by order of group importance).

RESULTS

Findings from interviews revealed that the frequency of use of telehealth services varies across the state as a result of several factors, including space limitations and staff training. Patients, however, seem to be comfortable with the use of the new technology. The concept mapping exercise displayed a progression of issues that are perceived to have an impact on the use of this technology.

CONCLUSIONS

Technology use is affected by unforeseen variables, such as physical space limitations and examination room availability. Family concerns about patient privacy issues were rare and were resolved quickly by the health care practitioner. Although using this equipment is not difficult, the search for user-friendliness should be continued. Staff engagement early in the process likely will result in a greater likelihood of use of the technology.telehealth, telemedicine, child protection, child abuse and neglect, concept mapping.

Complete sequence of the 23-kilobase human COL9A3 gene. Detection of Gly-X-Y triplet deletions that represent neutral variants

We report the complete sequence of the human COL9A3 gene that encodes the alpha3 chain of heterotrimeric type IX collagen, a member of the fibril-associated collagens with interrupted triple helices family of collagenous proteins. Nucleotide sequencing defined over 23,000 base pairs (bp) of the gene and about 3000 bp of the 5'-flanking sequences. The gene contains 32 exons. The domain and exon organization of the gene is almost identical to a related gene, the human COL9A2 gene. However, exon 2 of the COL9A3 gene codes for one -Gly-X-Y- triplet less than exon 2 of the COL9A2 gene. The difference is compensated by an insertion of 9 bp coding for an additional triplet in exon 4 of the COL9A3 gene. As a result, the number of -Gly-X-Y- repeats in the third collagenous domain remains the same in both genes and ensures the formation of an in-register triple helix. In the course of screening this gene for mutations, heterozygosity for separate 9-bp deletions within the COL1 domain were identified in two kindreds. In both instances, the deletions did not co-segregate with any disease phenotype, suggesting that they were neutral variants. In contrast, similar deletions in triple helical domain of type I collagen are lethal. To study whether alpha3(IX) chains with the deletion will participate in the formation of correctly folded heterotrimeric type IX collagen, we expressed mutant alpha3 chains together with normal alpha1 and alpha2 chains in insect cells. We show here that despite the deletion, mutant alpha3 chains were secreted as heterotrimeric, triple helical molecules consisting of three alpha chains in a 1:1:1 ratio. The results suggest that the next noncollagenous domain (NC2) is capable of correcting the alignment of the alpha chains, and this ensures the formation of an in-register triple helix.

Molecular cloning of the alpha 3 chain of human type IX collagen: linkage of the gene COL9A3 to chromosome 20q13.3

Type IX collagen is composed of three polypeptides derived from the human genes COL9A1, COL9A2, and COL9A3 that assemble to form a mature collagen molecule with the structure alpha 1(IX)alpha 2(IX)alpha 3(IX). We have identified overlapping cDNA and genomic clones that encode for the entire alpha 3 chain of human type IX collagen. Tryptic peptides from the human alpha 3(IX) collagen chain were subjected to N-terminal amino acid sequencing, and a stretch of 124 contiguous amino acids that included the NC1, COL1, and NC2 domains was obtained. Degenerate oligonucleotide primers were designed based on the amino acid sequences of the human tryptic peptides as well as bovine peptides and sequences from chicken cDNA clones. These primers were used to amplify three overlapping PCR products that covered the majority of the human alpha 3(IX) collagen. PCR products were then used to identify overlapping cDNA clones from a human chondrocyte library. A lambda genomic clone was identified that contained the 5'-most exon that encodes the signal peptide to complete the entire structure of the human alpha 3(IX) collagen chain. Genomic amplification identified a single-strand conformational polymorphism in COL1 that was used to map COL9A3 to chromosome 20q13.3 by linkage analysis. The present study completes the structure of human type IX collagen, and linkage for COL9A3 completes the genomic mapping of cartilage collagen genes. These data will greatly assist the genetic screening of families with degenerative cartilage and eye diseases by allowing investigators to screen for a complete set of candidate collagen gene markers.

Schwannoma of the vagus nerve

A case is described in which severe bradycardia complicated removal of a Schwannoma of the vagus nerve in the parapharyngeal space. The presentation of this rare tumour is discussed.

Vitamin C and post-suxamethonium pains

A double-blind trial of the effects of vitamin C on the frequency, severity and duration of post-suxamethonium pains was performed. Fifty-three patients undergone bronchoscopy received either a placebo or 10 g of vitamin C. No beneficial effect was demonstrated. In 18 patients no relationship was found between pre-anaesthetic buffy layer vitamin C levels and the subsequent pains. Measurement of buffy layer and plasma vitamin C levels before and after anaesthesia did not suggest that vitamin C deficiency occurs during or immediately after administration of suxamethonium. It is concluded that the administration of vitamin C cannot be recommended as a means for prevention of suxamethonium pains.