Effect of prolonged exercise and pre-exercise dietary manipulation on hepatic triglycerides in trained men.

The purpose of this study was to examine the effect of exercise and pre-exercise dietary manipulation on hepatic triglyceride concentration (HTGC). HTGC was measured by proton magnetic resonance spectroscopy ((1)H-MRS) before and after 90 min of moderate intensity cycling in six endurance trained males following 67 h of mixed diet (M) and an isocaloric minimal carbohydrate (2%) high fat (83%) diet (HF). Diets were administered by balanced crossover design. Whole-body fat oxidation, plasma-free fatty acid (FFA), glycerol and triglyceride concentrations were significantly elevated during exercise in HF versus M (P < 0.05 for all). There was no significant treatment × time interaction for HTGC (P = 0.368). However, there was a significant net increase in HTGC (time effect) during the combined 6 h exercise and post-exercise period (P = 0.037). In conclusion, we observed no measurable net change in the hepatic triglyceride pool across a period involving a prolonged exercise bout. Furthermore, manipulation of pre-exercise dietary intake did not influence the interaction between the hepatic triglyceride concentration and exercise in lean trained men. This supports the contention that hepatic triglycerides do not meaningfully contribute to the high rate of fat oxidation observed during acute exercise, or the enhancement of this with regular exercise training and/or pre-exercise dietary manipulation.

The bacteriology of bone allografts.

We report the contamination rate in the Cambridge bone bank of 35 consecutive allograft specimens, all harvested in a clean-air environment, using a strict aseptic technique and antibiotic cover. Five of 27 femoral heads taken from living donors and three of eight massive allografts taken from cadavers were found to be contaminated. The contaminated femoral heads were discarded. All massive allografts were rendered sterile by gamma-irradiation. It is important to exclude bacteriological contamination of harvested and banked bone.

Early outcome and cost-effectiveness of endoscopic versus open carpal tunnel release: a randomized prospective trial.

Proponents of endoscopic carpal tunnel release have been advocating the technique for more than 10 years but there is still debate about its efficacy, safety and cost-effectiveness. We have performed a randomized, prospective, blind trial to compare early outcome after single portal endoscopic or open carpal tunnel surgery and to assess the cost-effectiveness of the procedures. There were no significant differences in symptom and functional activity scores, grip strength or anterior carpal pain in the first 3 months. For those in employment, we found a statistically significant difference between the two treatment groups with the endoscopic group returning to work, on average, 8 (95% CI, 2-13 days) days sooner than the open group. This translates into a cost saving to industry. There were no major neurovascular complications in either group. On the basis of these findings, we recommend that endoscopic carpal tunnel release should be considered in the employed as a cost-effective procedure, but perhaps not in the general population as a whole.

De la Caffinière thumb trapeziometacarpal joint arthroplasty: 16-26 year follow-up.

Seventy-one patients (93 implants) had a de la Caffinière prosthesis implanted between 1980 and 1989 and were reviewed and reported in 1997. We reviewed this series 10 years later. Similar outcome measures were used as in the original study, pinch and grip strength measured and validated outcome scores obtained (DASH and EQ-5D). Radiographic outcome was assessed. Twenty-six patients with 39 implants were available for review at a mean of 19 years (range, 16-26 years). Survivorship at 26 years was 73.9% (95% CI, 61.2 to 86.6) for re-operation and 26.0% (95% CI, 0 to 52.7) for all failure. Patients had satisfactory power and thumb mobility and continued to be satisfied without pain. Registries should log such prostheses and add to implant survival data.

Telephone clinic follow-up following carpal tunnel decompression.

This paper investigates the feasibility of a telephone clinic follow-up service for patients undergoing carpal tunnel decompression. Six hundred and thirty patients were recruited over a 2-year period and we assessed their outcome and satisfaction level in the service, using a pre-determined questionnaire 6 weeks following surgery. The telephone clinic was overseen by a surgical care practitioner. We followed up 598 patients (93%) in total, and found 42 patients to be dissatisfied with the service (7%). These patients were referred for outpatient consultation and investigation. Most patients were satisfied with their surgical outcome and found the telephone clinic service to be convenient and effective. Cost analysis calculations estimated a potential saving of pound 45,958 over the 2-year period when compared to standard outpatient consultation. This model has been developed in our trust to follow up patients undergoing similar minor hand surgery.

Effect of altered pre-exercise carbohydrate availability on selection and perception of effort during prolonged cycling.

This study assessed the effect of altered carbohydrate (CHO) availability on self-selected work rate during prolonged time-trial cycling. Eight endurance-trained men undertook two experimental cycling time-trials after glycogen-depleting exercise and 2 days of: (a) high (9.3 +/- 0 g CHO kg(-1) day(-1)) (HC) and (b) low CHO intakes (0.6 +/- 0.1 g CHO kg(-1) day(-1)) (LC), via a double-blinded crossover design. All feedback regarding performance was removed during both exercise trials. Self-selected external power output was not different during the first 2 h of exercise between experimental conditions (P > 0.05), despite reported sensations of increased tiredness before and during exercise, significantly reduced whole body CHO oxidation (P < 0.05), plasma lactate concentrations (P < 0.05) and earlier onset of fatigue during exercise in LC versus HC. Perceived exertion was not different throughout exercise between conditions (P > 0.05). Mean power output declined significantly in LC versus HC (P < 0.05) after approximately 2 h of exercise, and was associated with significant reductions in cadence, heart rate and plasma glucose concentration (P < 0.05). These results demonstrate that when compared with time-trial cycling performed after a HC diet, reduced CHO availability does not initially alter self-selected work rate in endurance athletes who are deceived of their CHO status prior to exercise. This finding suggests that reduced work rate during exercise following lowered CHO intake may, in part, be a consequence of the subject's awareness of dietary CHO restriction rather than solely a physiologically mediated action. Further research is required to distinguish the influence of circulating glucose and peripheral glycogen availability on pacing strategy during prolonged exercise.

Short-term suppression of plasma free fatty acids fails to improve insulin sensitivity when intramyocellular lipid is elevated.

AIMS: Metabolic responses to manipulation of the plasma free fatty acid (FFA) concentration were assessed in six healthy men via cross-over design to determine whether FFAs independently influence insulin sensitivity. METHODS: Intramyocellular lipid (IMCL) was measured by proton magnetic resonance spectroscopy and insulin sensitivity via frequently sampled intravenous glucose tolerance test (IVGTT) after 67 h of two identical low carbohydrate/high fat (LC) diets which were used to elevate IMCL and plasma FFAs. To uncouple the influence of FFAs and IMCL on insulin sensitivity, FFAs were suppressed 30 min prior to and during IVGTT in one treatment [LC + nicotinic acid (NA)] by NA ingestion. RESULTS: Vastus lateralis IMCL was significantly elevated in LC (13.3 +/- 1.1 x 10(-3)) and LC + NA (13.5 +/- 1.1 x 10(-3)) (P < 0.01 for both), but was not different between conditions (P > 0.05). Plasma FFAs were raised in LC (0.79 +/- 0.08 mmol/l) and LC + NA (0.80 +/- 0.11 mmol/l) (P < 0.01 for both) and were significantly reduced by NA ingestion prior to (0.36 +/- 0.05 mmol/l, P < 0.01) and during IVGTT (P < 0.05) in LC + NA. Despite marked differences in plasma FFA availability, insulin sensitivity and glucose tolerance were not different between LC and LC + NA (P > 0.05 for both). CONCLUSIONS: Plasma FFAs appear to exert no immediate effect on insulin sensitivity/glucose tolerance independent of their action on intracellular lipid moieties. Further research is required to elucidate the duration of FFA suppression required to restore insulin sensitivity following lipid-induced insulin resistance.