Release of VCAM-1 associated endothelial microparticles following simulated SCUBA dives.

Microparticles (MP) are shed into the circulation from endothelium following activation or apoptosis. Vascular cell adhesion molecule-1 (VCAM-1) is expressed on endothelial cells following activation and here we report quantification of VCAM-1 positive microparticles (VCAM + MP) following simulated SCUBA dives, breathing either air or oxygen. VCAM + MP were quantified pre-dive (09:00 and 13:00) and post-dive (+1, +3 and +15 h) on both air and oxygen dives and compared with control samples taken from the same subjects. VCAM + MP followed a similar trend in all experiments, however both dives caused a change in endothelial state, as measured by VCAM + MP. A significant increase in VCAM + MP was observed 1 h post-air dive relative to the control (p = 0.013), which was not observed after the oxygen dive (p = 0.095). Oxidative stress (TBARS) was correlated with VCAM + MP. Data presented highlights the potential of MP as a biological marker of both endothelial state and decompression illness.

Aseptic bone necrosis in an amateur scuba diver.

A case is reported that provides further evidence of an old occupational hazard, dysbaric osteonecrosis, presenting in a new population (sports scuba divers) who also appear to be at risk. It highlights the need for an accurate diagnosis of diving related illness.

Carbon monoxide poisoning: correlation of neurological findings between accident and emergency departments and a hyperbaric unit.

OBJECTIVES: To investigate and quantify the differences in neurological examination findings in patients acutely poisoned with carbon monoxide, between initial assessment at accident and emergency (A&E) departments and subsequently at a hyperbaric unit. METHODS: Retrospective case note review of all patients referred to the Hull Hyperbaric Unit for treatment of acute carbon monoxide poisoning between August 1998 and August 1999. Patients who were ventilated or less than 16 years old were excluded because of difficulty in assessing their neurological status. RESULTS: Thirty patients were included for analysis. The mean duration from exposure to assessment in A&E was four hours while patients were reviewed on average three hours later at the hyperbaric unit. Referrals came from 14 different hospitals. A history of loss of consciousness accounted for 70% of referrals. A mean of 3.2 neurological signs per patient was documented in A&E compared with 9.2 at the hyperbaric unit. Seventy nine per cent of abnormal neurological signs were not detected at A&E departments compared with 3% at the hyperbaric unit. The major source of discrepancy was in sharpened Rhomberg's test and heel-toe gait, in 13% of patients examined in A&E departments these signs were recorded as abnormal compared with 90% at the hyperbaric unit. CONCLUSION: There is a large discrepancy in neurological findings between assessment in A&E departments and the Hull Hyperbaric Unit. A number of factors may account for this including interobserver variation, patient deterioration during transfer, poor documentation, lack of understanding of the sequelae of carbon monoxide poisoning and inadequate examinations. Further research is required to quantify the impact of the various factors that may contribute to the differences in neurological findings.

Hyperbaric oxygen in the treatment of fecal incontinence secondary to pudendal neuropathy.

PURPOSE: Hyperbaric oxygen therapy has several physiologic effects on damaged nerves in animal models, which lead to an improvement in neurologic function. Idiopathic fecal incontinence secondary to pudendal neuropathy is usually treated with biofeedback, which shows improvement in only 50 percent of patients. METHODS: Thirteen patients (12 females, age range, 40-75 years) with chronic pudendal neuropathy and fecal incontinence were identified. They received 30 treatments of hyperbaric oxygen during a period of 6 weeks. Each treatment was at 2.4 atmospheres breathing pure oxygen for 90 minutes. Pudendal latencies were performed sequentially throughout the treatment and one and six months after it had finished. Questionnaires were used to assess improvements in symptoms and quality of life (Wexner fecal incontinence quality of life score). RESULTS: All patients completed the treatment without major complications. There was a consistent improvement of the latencies (on the left 2.36 msec initially, reduced to 2.08 msec at 6-month follow-up and on the right 2.23 msec, on the left reduced to 2.07 msec at 6 months). These improvements were significant (Wilcoxon's two-tailed, asymptomatic significance, comparing pretreatment to 6-month follow-up, left 0.005, right 0.003). Incontinence sores also improved (12.08 initially to 11.64 at the end of treatment, 10.55 at 1-month follow-up, and 10.45 at 6-month follow-up). Using the same test, the improvement in incontinence scores also was significant when comparing pre-end (0.05) and pre-one month (0.011) but not pre-six month (0.054). CONCLUSIONS: Hyperbaric oxygen therapy has improved pudendal nerve function and continence in this group of patients. The cause for this improvement in latencies is unclear at present but may be because of a direct effect on the nerve or an improvement in blood flow to the nerve through angiogenesis. However, these results are good enough to schedule further trials.

The role of hyperbaric oxygen therapy in ischaemic diabetic lower extremity ulcers: a double-blind randomised-controlled trial.

OBJECTIVE: ischaemic lower-extremity ulcers in the diabetic population are a source of major concern because of the associated high risk of limb-threatening complications. The aim of this study was to evaluate the role of hyperbaric oxygen in the management of these ulcers. METHOD: eighteen diabetic patients with ischaemic, non-healing lower-extremity ulcers were recruited in a double-blind study. Patients were randomly assigned either to receive 100% oxygen (treatment group) or air (control group), at 2.4 atmospheres of absolute pressure for 90 min daily (total of 30 treatments). RESULTS: healing with complete epithelialisation was achieved in five out of eight ulcers in the treatment group compared to one out of eight ulcers in the control group. The median decrease of the wound areas in the treatment group was 100% and in the control group was 52% (p=0.027). Cost-effectiveness analysis has shown that despite the extra cost involved in using hyperbaric oxygen, there was a potential saving in the total cost of treatment for each patient during the study. CONCLUSION: hyperbaric oxygen enhanced the healing of ischaemic, non-healing diabetic leg ulcers and may be used as a valuable adjunct to conventional therapy when reconstructive surgery is not possible.

The Raw and the Stolen. Cooking and the Ecology of Human Origins.

Cooking is a human universal that must have had widespread effects on the nutrition, ecology, and social relationships of the species that invented it. The location and timing of its origins are unknown, but it should have left strong signals in the fossil record. We suggest that such signals are detectable at ca. 1.9 million years ago in the reduced digestive effort (e.g., smaller teeth) and increased supply of food energy (e.g., larger female body mass) of early Homo erectus. The adoption of cooking required delay of the consumption of food while it was accumulated and/or brought to a processing area, and accumulations of food were valuable and stealable. Dominant (e.g., larger) individuals (typically male) were therefore able to scrounge from subordinate (e.g., smaller) individuals (typically female) instead of relying on their own foraging efforts. Because female fitness is limited by access to resources (particularly energetic resources), this dynamic would have favored females able to minimize losses to theft. To do so, we suggest, females formed protective relationships with male co-defenders. Males would have varied in their ability or willingness to engage effectively in this relationship, so females would have competed for the best food guards, partly by extending their period of sexual attractiveness. This would have increased the numbers of matings per pregnancy, reducing the intensity of male intrasexual competition. Consequently, there was reduced selection for males to be relatively large. This scenario is supported by the fossil record, which indicates that the relative body size of males fell only once in hominid evolution, around the time when H. erectus evolved. Therefore we suggest that cooking was responsible for the evolution of the unusual human social system in which pair bonds are embedded within multifemale, multimale communities and supported by strong mutual and frequently conflicting sexual interest.