Muscle 'regenerative potential' determinesphysical recovery following total knee replacement.

OBJECTIVES: Lower limb muscle power is thought to influence outcome following total knee replacement (TKR). Post-operative deficits in muscle strength are commonly reported, although not explained. We hypothesised that post-operative recovery of lower limb muscle power would be influenced by the number of satellite cells in the quadriceps muscle at time of surgery. METHODS: Biopsies were obtained from 29 patients undergoing TKR. Power output was assessed pre-operatively and at six and 26 weeks post-operatively with a Leg Extensor Power Rig and data were scaled for body weight. Satellite cell content was assessed in two separate analyses, the first cohort (n = 18) using immunohistochemistry and the second (n = 11) by a new quantitative polymerase chain reaction (q-PCR) protocol for Pax-7 (generic satellite cell marker) and Neural Cell Adhesion Molecule (NCAM; marker of activated cells). RESULTS: A significant improvement in power output was observed post-operatively with a mean improvement of 19.7 W (95% confidence interval (CI) 14.43 to 30.07; p < 0.001) in the first cohort and 27.5 W (95% CI 13.2 to 41.9; p = 0.002) in the second. A strong correlation was noted between satellite cell number (immunohistochemistry) and improvement in patient power output (r = 0.64, p = 0.008). Strong correlation was also observed between the expression of Pax-7 and power output (r = 0.79, p = 0.004), and the expression of NCAM and power output (r = 0.84, p = 0.001). The generic marker explained 58% of the variation in power output, and the marker of activated cells 67%. CONCLUSIONS: Muscle satellite cell content may determine improvement in lower limb power generation (and thus function) following TKR.

Biotransformation of tri-substituted methoxyamphetamines by Cunninghamella echinulata.

1. Four trimethoxyamphetamine analogues were incubated with the filamentous fungus Cunninghamella echinulata. 2. 2,4,5-Trimethoxyamphetamine and 2,5-dimethoxy-4-ethoxyamphetamine were poorly metabolized by C. echinulata ATCC 9244 and C. echinulata var. elegans ATCC 9245. 2,5-Dimethoxy-4-(n)-propoxyamphetamine was mainly metabolized through N-acetylation and O-dealkylation with minor amounts of several aliphatic hydroxylation metabolites formed. 2,5-Dimethoxy-4-methylthioamphetamine was extensively metabolized to the corresponding sulphoxide. 3. 2,5-Dimethoxy-4-methylthioamphetamine metabolism was inhibited by ethanol and quinidine. Sparteine did not inhibit the formation of the sulphoxide and may have shunted the substrate through alternate metabolic pathways. 4. Incubation conditions can affect the rate and extent of fungal biotransformation of 2,5-dimethoxy-4-methylthioamphetamine, and influence dextrose utilization, ammonia formation and pH.

Investigation, follow-up and recurrence after resection of colorectal cancer.

A study was undertaken to determine the patterns of management in the 2 years following resection of colorectal cancer by Victorian surgeons. Patients were identified by the Victorian Cancer Register as having colorectal cancer diagnosed between July 1 and December 31 1987. The surgeon of each of the 947 eligible patients who underwent surgery was sent a questionnaire seeking information about the pre-operative investigation, type of surgery and subsequent line of referral. Only 16% of colonic cancers and 39% of rectal cancers were biopsied pre-operatively and colonoscopy was undertaken in one-half and one-third respectively. Of the 737 responses, 555 patients were considered to have had curative surgery, and details of their follow-up during the four 6-month periods following surgery was analysed; this includes the effect of tumour stage and surgeon activity on the use and frequency of each test. Most patients had a clinical examination in each of the 6 month periods, but almost half did not have a colonoscopy and two-thirds did not have the serum CEA level measured at all. Only one in eight had a chest X-ray and fewer had the liver scanned during this 2 year period. Eighty-two patients (20% of those satisfactorily followed) suffered a recurrence during this period. Twenty-six were asymptomatic at the time of recurrence and were diagnosed by a routine test and of these, eight were diagnosed by tests used infrequently. Sixteen (20%) were considered surgically curable.

Myeloma associated scleromyxedema with extensive involvement of small bowel.

The details of a patient with disseminated scleromyxedema related to multiple myeloma are presented. Investigation demonstrated extensive accumulation of mucopolysaccharides in the skin, bone marrow and the small bowel submucosa. The latter finding is a most unusual manifestation of scleromyxedema and appeared to correlate with the patient's symptoms on presentation.

Reduction in mortality from upper gastrointestinal haemorrhage.

A study of 2377 cases of haemorrhage from the upper gastrointestinal tract shows a significant fall in mortality rate--from 15.5% in the period of retrospective study from 1961 to 1970 to 7% in the prospective study from 1972 to 1982. The fall in mortality rate from non-variceal bleeding was from 12.8% to 5%. In the second five years of the prospective study, the total mortality rate was 5.8%, with 4.5% for non-variceal haemorrhage. This improvement occurred despite a significant rise in the proportion of patients of 60 years of age and over, and was particularly evident in patients with bleeding chronic gastric ulcers. There was also a significant reduction in mortality in the 60 years and over age group in the latter five years of the prospective study. The data suggest that there were three aspects of management which were important in the reduction of mortality. These were early fibreoptic endoscopic diagnosis, improved resuscitation and postoperative care, and early control of bleeding from oesophageal varices by balloon tamponade and surgery in selected cases. These complicated procedural aspects of management are best applied in a special unit for the treatment of patients with haemorrhage from the upper gastrointestinal tract. It is concluded that there has been significant progress in the treatment of this problem during the last decade.