Megadose vitamin C in treatment of the common cold: a randomised controlled trial

Letter to the editor commenting on the conflicting evidence that increased intake of vitamin C enhances the natural protective mechanisms of the body and decreases both the incidence and severity of the common cold

Cholesterol 'solitaire' gallstones and bacteria

The aetiology of cholesterol gallstone formation has largely concentrated on the cholesterol crystal pronucleation - bile salt micelle insolubility mechanism. Recently bacteria have been implicated as an additional mechanism that may well further enhance multiple cholesterol gallstone nidation and growth. We investigated gallbladder bile with single cholesterol gallstones from 27 patients. Gallbladder bile samples were aspirated from the gallbladder at the time of surgery from each patient and immediately cultured for aerobic and anaerobic bacterial growth. All samples tested returned a result of no growth after 5 days incubation. Subsequent total bile salts, cholesterol and phospholipid analysis of a sample of the gallbladder bile confirmed that the bile samples were supersaturated with cholesterol. The mean (SD) bile saturation index was 1.82 (0.21) [95%CI: 1.41, 2.22].Microscopic examination of bile under direct and polarized light confirmed abundant cholesterol precipitation as cholesterol monohydrate crystals. Chemical analysis of the gallstones showed a mean (SD) % dry weight of cholesterol of 87.5 (1.81)% [95%CI: 84.0, 91.1]. IR spectra confirmed cholesterol as the principal structural component. Employing the polymerase chain reaction technique coupled with a primer set universal for bacterial species, bacterial DNA was detected in the nidus area of 5 single cholesterol gallstones from 5 separate patients.As no bacterial growth was cultured we suspect the bacterial DNA detected were most probably from dead organisms preserved within the gallstone matrix from a time pertaining to gallstone nidation. Bacterial DNA sequences were consistent with those from enterobacterial species. Pathology reports concerning the gallbladder consisted of acute cholecystitis (37%) and chronic cholecystitis (63%). Gallstones found to have bacterial DNA sequences within their central matrix structure were all from the group of chronic cholecystitis.We postulate that bacteria may colonize cholesterol ‘rich’ gallstones, a gallstone type previously thought not to be associated with bacterial infections. Bacterial colonization of the gallbladder may be a transient event. Hence, bacteria if present in bile in conjunction with bile supersaturated with cholesterol would enhance gallstone nidation