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Biomedical subjects

H Gough

Publications and source records attributed to H Gough.

13 recordsLinked to original sources

Human salivary sugar clearance after sugar rinses and intake of foodstuffs.

The aetiology of dental caries is in part related to the retention time of dietary carbohydrates in the oral cavity and their subsequent metabolism by the oral bacteria. Salivary clearance of fermentable carbohydrates from three different foodstuffs was examined in 5 subjects and analyses performed by high-performance anion-exchange chromatography with pulsed amperometric detection. The clearance of glucose, fructose, sucrose, maltose and sorbitol rinses was studied as well as that of chocolate bars, white bread and bananas. Of the sugar rinses studied, sucrose was removed from saliva most rapidly whilst appreciable levels of sorbitol remained even after 1 h. Clearance of residual carbohydrates from bananas and chocolate bars seemed marginally faster than in the case of bread, but sucrose levels still tended to fall more quickly than other carbohydrates studied. Surprisingly, carbohydrate residues from the three foods studied were still present in the mouth even 1 h after ingestion, which is longer than has hitherto been reported.

Bread

Human salivary glucose analysis by high-performance ion-exchange chromatography and pulsed amperometric detection.

The aim of this project was to develop an analytical procedure with the required level of sensitivity for the determination of glucose concentrations in small volumes of unstimulated fasting whole saliva. The technique involves high-performance ion-exchange chromatography at high pH and pulsed amperometric detection. It has a high level of reproducibility, a sensitivity as low as 0.1 mumol/l and requires only 50 microliters samples (sensitivity = 0.002 pmol). Inhibition of glucose metabolism, by procedures such as collection into 0.1% (w/v) sodium fluoride, was shown to be essential if accurate results are to be obtained. Collection on to ice followed by storage at -20 degrees C was shown to be unsuitable and resulted in glucose loss by degradation. There were inter- and intraindividual variations in the glucose concentration in unstimulated mixed saliva (range; 0.02-0.4 mmol/l). The procedure can be used for the analysis of other salivary carbohydrates and for monitoring the clearance of dietary carbohydrates from the mouth.

Chromatography, Ion Exchange

A comparative study of the relative effects of anticonvulsant drugs and dietary folate on the red cell folate status of patients with epilepsy.

In a survey of the red cell folate status of 200 patients with epilepsy, compared to 72 controls, we found that median red cell folate levels were reduced significantly in patients treated with phenytoin (p less than 0.01) or carbamazepine (p less than 0.001) alone. Patients taking more than one drug had reduced levels also (p less than 0.001), but in patients treated with sodium valproate alone there was no significant decrease in red cell folate levels compared to controls. Twenty-two per cent of patients in the group taking more than one drug had reduced levels of red cell folate compared with 17 per cent of those taking carbamazepine alone, 13 per cent of those taking phenytoin only, and 9 per cent of those taking sodium valproate only. Dietary folate intake was significantly reduced in all the patient groups compared with controls (p less than 0.001 for the carbamazepine and phenytoin groups, p less than 0.01 for the polypharmacy and sodium valproate groups); a significant correlation between red cell folate levels and dietary folate was not established. Significant negative relationships were established between carbamazepine dose (r = -0.35, p less than 0.01) or serum level (r = -0.27, p less than 0.05) and red cell folate level in patients on one drug only. The correlation between dose or serum level of phenytoin and red cell folate level was also negative but did not reach significance. Our findings show that all anticonvulsant drugs interfere with folate metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

A comparative study of the relative influence of different anticonvulsant drugs, UV exposure and diet on vitamin D and calcium metabolism in out-patients with epilepsy.

The biochemical parameters associated with vitamin D metabolism, calcium, 25-hydroxy-vitamin D (25OHD) and alkaline phosphatase levels were assessed in 226 out-patients with epilepsy. Patients were grouped depending on the drug treatment; carbamazepine, phenytoin, phenobarbitone and sodium valproate used alone as monotherapy and a combination of these drugs as polytherapy. The most severe alterations occurred in the polytherapy group. Hypocalcaemia was more severe in the phenobarbitone monotherapy group than the carbamazepine or the phenytoin groups. No patient on sodium valproate monotherapy had subnormal levels of calcium (less than 2.1 mmol/l). 25OHD levels were similarly reduced in the carbamazepine, phenytoin and the phenobarbitone groups with no reduction in the sodium valproate group. Significant elevations in alkaline phosphatase levels were evident in all patient groups except the sodium valproate group. This study confirms biochemical evidence for anticonvulsant osteomalacia when the enzyme-inducing drugs are used, the degree of severity depending on the drug regimen.

Adult

Serum bilirubin levels with antiepileptic drugs.

The incidence of reduced bilirubin levels in 168 outpatients with epilepsy, compared with levels in 69 controls, has been investigated. Highly significant (p less than 0.001) reductions in average bilirubin levels were noted for carbamazepine (CBZ), phenytoin (PHT), phenobarbital (PB), and multiple drug groups. A marginally significant (p less than 0.05) reduction in bilirubin levels occurred in patients treated with valproate (VPA) which, unlike the other drugs, has not been shown to induce hepatic enzymes.

Adult