Calin--a platelet adhesion inhibitor from the saliva of the medicinal leech.

The saliva of the medicinal leech, Hirudo medicinalis, contains a potent, hitherto unsuspected, inhibitor of collagen-mediated platelet adhesion/aggregation. Calin, of molecular size approximately 65,000 (reduced), has a rapid (1-10 min) effect on collagen which is reflected in its ability to suppress collagen-induced platelet aggregation, as well as adhesion of platelets to collagen-coated microcarrier beads. It also causes flocculation of Type I collagen fibril suspensions. Calin is differentiated from leech collagenase in two ways: (1) by demonstrating, by SDS-PAGE analysis of the products of incubations of Calin with Type I collagen at 37 degrees C, that Calin binds to but does not cleave collagen; and (2) by showing that Calin cannot be purified using the methods used to isolate leech collagenase. Calin's rapid and unusual interaction with collagen makes it a prime candidate for one of the agents that are the causative factors of the prolonged bleeding phenomenon seen after leech bites.

Complementary medicine in the United Kingdom: patients, practitioners, and consultations.

Practitioners of complementary medicine took part in a questionnaire-based survey in 1980-81. Compliance was almost 100% in Oxfordshire and the Cambridge area but much less in five other areas of the UK. There were about 12 practitioners per 100 000 population, including all therapeutic specialties. Half the practitioners had had formal education; less than half were in full-time practice. They charged an average of 10 pounds for the first visit and 8 pounds for subsequent visits, which took 51 and 36 min, respectively. Annual consultation rates were 19.5-25.7 per 100 population (11.7-15.4 million consultations); there were about 2 million consultations each for acupuncture, osteopathy, and chiropractic. The average course of treatments was 9.7. Two-thirds of the patients were female, and most were young or middle-aged and of the higher social classes. Although the data indicate a growing and substantial subsidiary health-care system in the UK, there is evidence that it complements rather than competes with conventional medicine.

Vancomycin therapy for methicillin-resistant Staphylococcus aureus.

Ten patients with bacteremia due to methicillin-resistant Staphylococcus aureus were treated with vancomycin. These patients were compared with matched controls, nine bacteremic patients with methicillin-sensitive S. aureus, and one patient with penicillin-sensitive S. aureus. Controls were treated with a penicillin. There were no significant differences in time to defervescence, metastatic infections, relapse, mortality, need for surgical drainage, or duration of therapy. Fifteen of 19 episodes of serious methicillin-resistant S. aureus infection responded to vancomycin. Severe toxic effects included tinnitus, neutropenia, rash, and possible nephrotoxicity. Tolerance (a minimal bactericidal concentration to minimal inhibitory concentration ratio of at least 32), but not a minimal bactericidal concentration of at least 32 mg/L, correlated with therapeutic failure (respectively, p = 0.04 and p = 0.11, Fisher's exact test). Bacteremic infections due to methicillin-resistant and methicillin-sensitive S. aureus cause similar morbidity and mortality. Vancomycin is effective but potentially toxic therapy for most serious infections due to methicillin-resistant S. aureus. In-vitro tests may not predict therapeutic efficacy.