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Biomedical subjects

G D Bell

Publications and source records attributed to G D Bell.

At least 145 records · Page 8Linked to original sources

The [14C]-aminopyrine breath test. A comparison of different forms of analysis.

1 Following ingestion of [14C]-aminopyrine, breath 14CO2 data were analysed from normal individuals, patients with hepatic disease, epileptics receiving anticonvulsant therapy and volunteers before and after treatment with glutethimide. 2 The 'standard' 2 h [14C]-aminopyrine breath test discriminated successfully between the main groups but failed to detect the change in microsomal enzyme function produced by glutethimide. 3 A 'modified' form of the 2 h breath test calculated from the area under the breath specific activity curve detected the increase in demethylation following glutethimide. 4 The breath elimination constant (Kb) derived from the breath 14CO2 disappearance curve was as sensitive as the 'modified' 2 h breath test and was simpler to compute. 5 Glutethimide 500 mg/day for 14 days resulted in a 42% increase in the metabolic clearance of antipyrine and a 26% increase in demethylation of [14C]-aminopyrine.

Aminopyrine↗

Rowachol--a possible treatment for cholesterol gallstones.

It has been claimed that Rowachol, a proprietary choleretic, is occasionally successful in the treatment of gallstones. In gallstone patients we have examined its effect on the lipid composition of (1) samples of fasting gall bladder bile obtained at the time of cholecystectomy, and (2) T-tube bile on the tenth post-operative day. In a dose of two capsules, three times a day for only 48 hours, Rowachol significantly lowered the cholesterol solubility of both gall bladder (P less than 0.001) and T-tube bile (P less than 0.05). Rowachol in a dose of one capsule three times a day for 48 hours did not alter bile composition, while four capsules four times a day for a similar period caused a significant (P less than 0.05) deterioration in biliary lipid composition. The possible mechanisms of action of Rowachol and their therapeutic implications are discussed.

Adult↗

Effect of ioglycamide (Biligram) on bile flow and biliary lipid secretion in man.

Twenty-one anicteric patients with a t-tube in situ were studied between the ninth and 11th postoperative days. Eleven patients were given an intravenous infusion of the biliary contrast agent ioglycamide (Biligram), while the other 10 acted as controls. Bile flow was recorded and the biliary concentrations of ioglycamide, bile salt, phospholipid, and cholesterol estimated in the two groups. The biliary excretion of ioglycamide was associated with a significant choleresis which was probably due to the obligatory coupling of the osmotically active contrast agent molecules with water. Biliary ioglycamide excretion did not significantly alter bile salt secretion rates. In contrast, the biliary secretion of both phospholipid and cholesterol was significantly lowered (P less than 0.001). Unlike chenodeoxycholic acid, ioglycamide significantly reduced bile acid independent cholesterol secretion (P less than 0.01), although secretion rate in terms of mumol of bile acid was essentially unchanged.

Bile↗

Ioglycamide (Biligram) studies in man--relation between plasma concentration and billary excretion.

Plasma ioglycamide concentration was linearly related to the rate of intravenous infusion over a dose range of from 1 to 4 mg per kg per min. The relation between plasma and biliary concentration of ioglycamide was studied in 15 anicteric patients with a T-tube in situ. Peak biliary concentrations and excretory rates of ioglycamide were seen when the plasma concentration was greater than 1500 micrograms per ml. The mean biliary transport maximum (Tm) for ioglycamide in man was 31.6 mg/min (range 22.0-40.4). The results suggest that near optimal concentrations of iodine in the bile duct can be obtained during intravenous cholangiography if ioglycamide is infused for one hour at a rate of about 4 mg per kg per min.

Bile↗

Ioglycamide (Biligram) studies in man. Radiological opacification of the bile duct. A comparison of a number of different methods.

Intravenous cholangiography was carried out in 80 anicteric patients using ioglycamide (Biligram). Twenty patients were given a 30 ml ampoule of 35% ioglycamide as a slow hand injection over ten minutes; the remainder were given ioglycamide by one hour slow drip infusion at a rate of 2, 3, or 4 mg per kg body weight per minute. The radiological opacification of the bile duct was then assessed independently by two radiologists. There was a statistically significant difference between the bile duct opacification found in patients given either 3 or 4 mg/kg/min of ioglycamide for one hour compared with those given ioglycamide either by ten minute injection or by 2 mg/kg/min drip infusion.

Adult↗

Ioglycamide (Biligram) studies in man--plasma binding, renal and biliary excretion studies in jaundiced and anicteric patients.

When five patients with varying degrees of hepatic impairment and a T-tube in situ were given intravenous ioglycamide at a rate of 2 mg/kg/min for two hours the mean biliary excretion in the first two hours was only 3.2% of the administered dose. In contrast, in five T-tube patients with relatively normal liver function the mean biliary excretion over the same time interval was 20.6%. The mean plasma concentration of ioglycamide achieved at the end of a two-hour intravenous infusion at 2 mg/kg/min was 1427 +/- 187 microgram/ml in six anicteric patients and 1262 +/- 82 in six jaundiced patients. Despite these very similar plasma levels the 24-hour urinary excretion of ioglycamide was 42.3 +/- 3.8% of the administered dose in the patients with jaundice compared with only 18.1 +/- 2.4% in the anicteric group. These differences probably reflect the fact that the percentage of unbound contrast agent in the plasma of the jaundiced group (11.9 +/- 1.9%) was significantly higher than that of the anicteric group (6.4 +/- 0.9%). It is suggested that bilirubin and possibly other substances in the plasma are competing with ioglycamide for binding sites on albumin. These factors need to be borne in mind when performing intravenous cholangiograms on jaundiced patients.

Aged↗

Section II: General orthopaedics. Anterior cervical fusion for trauma.

Anterior bone grafts of 24 injured cervical spines were reviewed with respect to early postoperative instability and eventual malunion. Spinal redislocation or graft extrusion occurred in 21% representing failure to attain early stability. In 38%, the late complication of kyphotic malunion occurred, averaging 21%. The Yale instability criteria were fulfilled in 15 cases and mechanical complications developed in 87% of these. When posterior instability was present, the mechanical complication rate rose to 92%. Early stabilization of most neck injuries is not achieved by the anterior bone graft and its use as a means of "stabilization" is unsubstantiated by clinical experience.

Adolescent↗

Chenodeoxycholic acid treatment of gallstones. A follow-up report and analysis of factors influencing response to therapy.

We treated 70 patients with gallstones with chenodeoxycholic acid over 3 1/2 years and analyzed the factors influencing the outcome of therapy. This treatment was unsuccessful in 11 patients with radiopaque gallstones and in seven with nonfunctioning gallbladders, but 64 per cent with radiolucent gallstones treated for six months or more showed partial or complete gallstone dissolution, and of those whose bile became unsaturated with cholesterol, 100 per cent had evidence of dissolution. In patients with partial or complete gallstone dissolution, the mean post-treatment biliary cholesterol saturation index--0.78 +/- 0.04 (S.E.M.)--was significantly less (P less than 0.001), and the dose of chenodeoxycholic acid (14.4 +/- 1.0 mg per kilogram of body weight per day) significantly more (P less than 0.025) than in those whose gallstones did not change (1.15 +/- 0.04 and 10.6 +/- 1.2 respectively). In patients with radiolucent gallstones, the dose of chenodeoxycholic acid should be based on body weight; 14 to 15 mg per kilogram of body weight per day effectively lowers the saturation index and dissolves gallstones.

Adult↗

The value of radiology in predicting gallstone type when selecting patients for medical treatment.

Since medical treatment of gallstones is confined to cholesterol-rich stones, the ability of clinical radiographs to predict gallstone type was tested prospectively by comparing the preoperative radiological appearance of gallstones from 57 unselected patients with cholelithiasis coming to cholecystectomy with the subsequent analysis of the stones both by X-ray diffraction and by chemical techniques. Fifty-two per cent of the patients had 'non-functioning' gallbladders which failed to opacify after at least two contrast examinations and 25 out of 50 had radioopaque stones. Of the 25 patients with radiolucent stones, the stones in 20 ((80%) were predominantly cholesterol in type but radiology was misleading in five; three contained 40-55% calcium salts but were still radiolucent while two were amorphous and contained less than 10% cholesterol by weight on chemical analysis. While radiology was sometimes misleading when the stones were small and irregular, large radiolucent stones with a smooth profile were invariably cholesterol-rich stones. The results also show that in men calcified stones were commoner than in women and that in older women the gallstones contained more calcium salts and less cholesterol than in younger women less than 50 yr). This paper analyses critically the value and limitations of clinical radiology in predicting gallstone type.

Adult↗