No abstract

We compared peri-prosthetic bone mineral density between identical cemented and cementless LCS rotating platform total knee arthroplasties. Two matched cohorts had dual energy x-ray absorptiometry scans two years post-operatively using a modified validated densitometric analysis protocol, to assess peri-prosthetic bone mineral density. The knee that was not operated on was also scanned to enable the calculation of a relative bone mineral density difference. Oxford Knee and American Knee Society scores were comparable in the two cohorts. Statistical analysis revealed no significant difference in absolute, or relative peri-prosthetic bone mineral density with respect to the method of fixation. However, the femoral peri-prosthetic bone mineral density and relative bone mineral density difference were significantly decreased, irrespective of the method of fixation, particularly in the anterior distal portion of the femur, with a mean reduction in relative bone mineral density difference of 27%. There was no difference in clinical outcome between the cemented and cementless LCS total knee arthroplasty. However, both produce stress-shielding around the femoral implants. This leads us to question the use of more expensive cementless total knee components.

Summary. In a survey of 46 randomly selected diabetic patients on biguanide therapy, 30% had malabsorption of vitamin B12. Withdrawal of the drug resulted in normal absorption in only half of those with malabsorption. In most patients with persistent malabsorption, the results of absorption tests with exogenous intrinsic factor suggested the diagnosis of coincidental intrinsic factor deficiency. Further considerations, however, led to the concept that biguanides can induce malabsorption by two different mechanisms. One of these is temporary and unrelated to intrinsic factor secretion and the other is permanent and mediated by depression of intrinsic factor secretion. Key-words:Biguanides, phenformin, metformin, vitamin B12 , intrinsic factor deficiency, malabsorption.Malabsorption of vitamin B12 is a well-known complication of biguanide therapy. Any disease causing malabsorption may, however, occur in diabetic patients and an interesting feature of studies of vitamin B12 absorption in diabetic patients on biguanides is the apparent rarity of such conditions. As we had formed an impression that anaemias not related to biguanide therapy occurred more often than might be expected, we decided to test this by a study of the absorption of vitamin Ba2 by diabetic patients on biguanides and extended this to the effects of metformin on the gastric secretory capacity of normal subjects. Subjects and Methods SubjectsForty-six diabetic patients on biguanide therapy were selected randomly for a survey of the capacity to absorb vitamin B12. Thirty-eight were female (aged 40-72 years, average 58 years) and eight were male (aged 45-72 years, average 59 years). The ratio of males to females is representative of the sex distribution of obese non-insulin-dependent diabetic patients attending the clinic. The average age of onset of diabetes was 50years in males (range 38-67years) and 51 years in females (range 32-75 years).Twenty-eight patients (24 males, four females) were studied on metformin 13 (three males, ten females) on phenformin and five (one male, four females) while on both drugs at different times. The dose of metformin ranged from i to 3 g daily, and the duration of treatment at the time of study was from 1 to 6 years; the dose of phenformin was 50 mg twice daily and the duration of treatment ranged between 3 months and 6 years. MethodsThe capacity to absorb vitamin B~2 was measured with a scanning type whole body monitor utilising six sodium iodide detectors each 15.2 cm diameter and 10.2 cm thick housed in a custom built room with 15 cm thick steel walls. The statistical accuracy of a result is + 5% (i.e.: 5 + 5%, 20 _+ 5%, etc.) and the mean coefficient of variation between results is 26%. A control series absorbed between 26% and 89% (mean + SD: 50.6 -!-_ 14.7%) of 1 Ixg radioactive cyanocobalamin and for routine purposes absorption of < 30% is regarded as subnormal. After preliminary scanning, oral doses of 1 gg, 0.25 j_tCi, 57Co or 58Co cyanocobalamin were given after a t2-h fast which was continued for a further...

Eight hypoxic male patients with stable chronic obstructive airways disease were submitted for combined anterior pituitary function testing. All subjects showed normal growth hormone and essentially normal cortisol responses to adequate hypoglycaemia, two subjects showed delayed responses of thyroid stimulating hormone to administered thyrotrophin releasing hormone and all had basal prolactin levels within normal limits. Basal levels of luteinising hormone were significantly lower than in the group of age-matched controls (p < 002) but there was a normal increment after the injection of gonadotrophin releasing hormone. Basal levels of follicle stimulating hormone were significantly lower than in the controls (p < 001), and there was also a reduced response from the pituitary after injection of gonadotrophin releasing hormone (p < 0-01). Resting levels of the thyroid hormones thyroxine and tri-iodothyronine were normal while the expected subnormal testosterone level was observed (p < 0 05). These results show that hypoxia can produce abnormalities of hypothalamic-pituitary function and that these are primarily located in the hypothalamicpituitary-testicular axis.While studying metabolic aspects of chronic obstructive airways disease (COAD), we have recently found reduced serum testosterone values in affected men,' and have been able to demonstrate an association between severity of hypoxia and degree of testosterone suppression.2 Theoretical consequences of endocrine abnormalities have been discussed in these communications with particular reference to the difference in body habitus between overweight chronic bronchitic "blue bloaters" and thin emphysematous "pink puffers." Though such hormonal changes had not previously been described in patients with COAD, reduced urinary 17-ketosteroid production had already been noted at high altitude3 and in emphysema.4 We have postulated that hypoxia produces low androgen output by suppressing hypothalamic-pituitary function. However, decreased response of testosterone secretion after testicular stimulation by injection of human chorionic gonadotrophin (HCG)

There is recent evidence that the inflammatory response may be important in the disproportionate loss of body cell mass in cancer patients. To examine this further, 18 male patients with lung or gastrointestinal cancer were studied over a 12-week period. In addition to weight, anthropometry, C-reactive protein (marker of the inflammatory response), albumin, and total body potassium were measured at baseline and 12 weeks. When those patients who lost total body potassium were compared with those who had not, there was a significant increase in the baseline and 12-week C-reactive protein concentrations (p < 0.05). The reduction in total body potassium was also associated with a reduction in triceps skinfold thickness (p < 0.05). There were significant correlations between the mean C-reactive protein concentration and the relative (r = -0.846, p < 0.001) and absolute (r = -0.806, p < 0.001) change in total body potassium over the follow-up period. This study demonstrates the association of a chronic inflammatory response with the rate of loss of body cell mass observed in cancer patients.