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Biomedical subjects

K Byth

Publications and source records attributed to K Byth.

65 records · Page 4Linked to original sources
PubMed1990

Hepatitis C virus in intravenous drug users.

Sera from 172 intravenous drug users were tested for the presence of antibodies to hepatitis C virus (anti-HCV). The results were analysed in relation to aspects of the history of drug use and evidence of liver disease. The presence of anti-HCV was strongly associated with duration of intravenous drug use. Two-thirds of patients were anti-HCV seropositive within two years of commencing regular intravenous drug use, and there was 100% seropositivity among people injecting drugs for more than eight years. Seropositivity for hepatitis C virus closely paralleled exposure to hepatitis B virus, which was also endemic in this population. In contrast, only one patient tested positive for antibodies to the human immunodeficiency virus. The presence of anti-HCV correlated poorly with biochemical markers of hepatitis. About half the patients with anti-HCV had normal serum levels of alanine aminotransferase, whereas an abnormal liver biochemistry was frequently observed in anti-HCV seronegative subjects. Previous studies of non-A, non-B hepatitis that have used abnormal liver biochemistry as a marker have underestimated the prevalence of chronic hepatitis among intravenous drug users; the use of a specific screening test reveals that infection with hepatitis C virus is very common in this population.

Adult↗
PubMed1990

Cost-effectiveness of cimetidine maintenance therapy in chronic gastric and duodenal ulcer.

The effects of cimetidine maintenance therapy on the socioeconomic life of patients with peptic ulcers in the 3 years after healing and the extent to which treatment was cost-effective were studied. Three hundred eleven patients with healed ulcers (184 gastric, 127 duodenal) were studied for periods of up to 3 years; 261 patients (152 gastric ulcer, 109 duodenal ulcer) completed the 3-year follow-up. Cimetidine (400 mg at night) was compared with placebo in a double-blind, randomized prospective study. Intention-to-treat analysis was used. In the placebo group, the major costs of ulcer disease in gastric ulcer patients were attributable to endoscopic procedures and absenteeism; in duodenal ulcer patients, the major costs were endoscopic procedures, absenteeism, and surgery. Cimetidine was cost-effective in both gastric ulcer and duodenal ulcer patients in the first 2 years after healing. Over the 3-year period it was also cost-effective, but no benefit was seen in the third year.

Absenteeism↗
PubMed1990

Phenylthiocarbamide taste sensitivity in chronic peptic ulcer.

Ability to taste phenylthiocarbamide is genetically determined and has been investigated as a possible genetic marker for disease. This study examined phenylthiocarbamide taste sensitivity in gastric and duodenal ulcer disease. The study sample included 164 patients with gastric ulcer, 134 with duodenal ulcer, and 299 community controls. Eight concentrations of phenylthiocarbamide in distilled water were obtained by binary serial dilution. The lowest concentration distinguished by taste from distilled water defined taste threshold. Bimodality of threshold distributions distinguished nontasters from tasters. Comparisons of patients with controls gave odds ratios of nontaste in gastric ulcer and duodenal ulcer of, respectively, 0.7 (P greater than 0.1) and 1.3 (P greater than 0.03). The power of detecting at least a twofold difference between patients and controls in the odds of nontaste was 80%. Nontaste was more common in duodenal than in gastric ulcer patients (odds ratio = 2.0, P = 0.02). Taste sensitivity was unassociated with other genetic factors related to ulcer--ABO blood group, secretor status, and serum pepsinogen 1 level. The difference between gastric and duodenal ulcer patients in the ability to taste phenylthiocarbamide may be genetic; however, this study's inability, despite substantial power, to detect at least a twofold difference between patients and controls suggests that if phenylthiocarbamide taste sensitivity is a genetic factor in peptic ulcer, the relationship is weak.

Adult↗
PubMed1987

Prognosis of chronic duodenal ulcer: a prospective study of the effects of demographic and environmental factors and ulcer healing.

The aim of this prospective study of 370 community based duodenal ulcer patients was to define the effect on duodenal ulcer course (from the aspect of symptom occurrence) of demographic and environmental factors, and of proven healing of index ulcer within four months. Follow up was three monthly, for up to three years. By survival analysis, it was found that marriage breakup adversely affected duodenal ulcer course, that age 50 years and under, female sex, and aspirin use tended to do so, and that smoking, alcohol ingestion, and paracetamol use did not. Proven healing of index ulcer within four months was associated with a small and non-significant reduction in symptom occurrence over time.

Age Factors↗
PubMed1986

The effect of maintenance cimetidine therapy on the medical, social and economic aspects of patients with chronic gastric ulcers. A placebo-controlled prospective study.

We studied the effect of cimetidine maintenance therapy on the socioeconomic life of patients with gastric ulcers in the year after healing and the extent to which treatment was cost-effective. One hundred and seventy patients with a healed ulcer were studied for periods of up to one year after healing; 116 patients completed one year of observation. A double-blind randomized prospective study was performed that compared cimetidine (400 mg at night) with placebo. Analysis was performed on the intention-to-treat principle. The treated group showed benefit over the placebo group; major or minor symptoms were experienced on fewer days, and more months were symptom-free. Male patients were wakened with ulcer pain on fewer nights, led a more normal social life, and had less ulcer-related sick-leave; female patients had less total sick leave. The proven ulcer recurrence rate was lower in the treated group. Fewer endoscopies were performed in this group and the resultant cost saving was equivalent to the cost expenditure on cimetidine treatment. A modest saving in wages was afforded treated patients in the workforce, due to the reduction in sick leave. The principal benefit of cimetidine treatment appeared to be the lessening of the pain and discomfort and, hence, the distress and anxiety that was associated with ulcer disease. The cost-saving due to the reduced number of endoscopies compensated for the cost-expenditure of the cimetidine treatment.

Adult↗
PubMed1986

Serum bile acid concentrations during pregnancy and their relationship to obstetric cholestasis.

We have prospectively studied changes in serum postprandial cholylglycine (CG) concentration during 297 pregnancies. We found an increase in CG concentration from 0.3 mumol/L at 15 weeks' pregnancy to 0.6 mumol/L at 40 weeks' pregnancy. Although this increase was statistically significant (p less than 0.005), median concentrations of CG remained well within the normal range (0-1.5 mumol/L). However, 10% of the group showed markedly elevated serum CG concentrations at 30 weeks' pregnancy, and the CG level in this group continued to rise during the third trimester. Pruritus was significantly more common in the group with elevated CG concentrations (48%) than in the group with normal CG levels (20%) (p less than 0.005). Serum CG was a much more sensitive predictor of pruritus during pregnancy than other biochemical liver tests. Elevated CG levels were found more commonly in Mediterranean and Asian patients than patients of other ethnic origins (p less than 0.025). No statistically significant associations were found between elevated CG concentrations and maternal age, number of previous pregnancies, pruritus during previous pregnancies, contraceptive-induced cholestasis, and fetal maturity. We conclude that obstetric cholestasis is probably much more common than previously suspected and that consideration should be given to the measurement of serum bile acids in all pregnant individuals with unexplained pruritus.

Adolescent↗
PubMed1985

Environmental factors in aetiology of chronic gastric ulcer: a case control study of exposure variables before the first symptoms.

The aim of the present study was to determine whether there is indication that either smoking, alcohol ingestion, or ingestion of analgesic or non-salicylate non-steroidal anti-inflammatory drugs plays any role in the development of chronic gastric ulcer disease. A group of 104 patients with gastric ulcer was compared with an age, sex and social grade matched community control population as regards exposure to the above factors during three time periods--the lifetime, five year and one year periods before the initial onset of the patients' ulcer symptoms. In all three study periods a statistically significant risk of gastric ulcer was found to be associated with smoking, and the daily use of aspirin, indomethacin and of other non-salicylate non-steroidal anti-inflammatory drugs as a group, but not with alcohol or daily use of paracetamol. As exposure to the environmental factors preceded the initial onset of ulcer symptoms, causal relationships are suggested. Assuming the association are causal, it can be calculated that possibly up to 80% of gastric ulcer disease is attributable to smoking and the daily ingestion of analgesic and anti-inflammatory drugs.

Acetaminophen↗
PubMed1984

Cimetidine reduces the risk of rebleeding from duodenal ulcers displaying signs of recent haemorrhage.

The presence of endoscopic signs of recent haemorrhage (SRH) greatly increases the risk of rebleeding from peptic ulcers. Fifty-five patients with acute bleeding from chronic duodenal ulcers with SRH completed a randomized double-blind trial to assess the effect of administration of cimetidine (800 mg daily intravenously for 2 days, then 1000 mg daily orally for 10 days in divided doses) versus placebo on rebleeding and need for emergency surgery. In the cimetidine group (n = 29), 5 rebled, compared with 11 receiving placebo (n = 26) (p less than 0.05; relative risk, 0.28, 95% confidence interval, 0.08-0.97). This reduction in rebleeding rate in the cimetidine-treated patients was observed only in subjects over 60 years of age. Fifteen patients receiving cimetidine required blood transfusion (mean, 2.3 +/- 0.6 (SEM) units per patient) compared with 19 receiving placebo (3.5 +/- 0.5) (p greater than 0.1). Emergency surgery to arrest bleeding was required in three patients receiving cimetidine and four receiving placebo (p greater than 0.5). Cimetidine therapy should be considered in patients more than 60 years old who present with haemorrhage from a chronic duodenal ulcer with SRH and who are at high risk of rebleeding.

Cimetidine↗
PubMed1984

Smoking, alcohol, analgesics, and chronic duodenal ulcer. A controlled study of habits before first symptoms and before diagnosis.

The aim of the study was to investigate the role of smoking and alcohol and analgesic ingestion in the aetiology of chronic duodenal ulcer (DU). Exposure to these variables was studied during the lifetime and 1 year before the first ulcer symptom and 1 month before a diagnosis. The ulcer group of 100 patients was compared with 100 community controls matched for age, sex, and social grade. In men there was an increased risk of DU associated with smoking and alcohol ingestion both during the lifetime and 1 year before the first symptom. In women, there was an increased risk associated with smoking during the lifetime before the first symptom and with alcohol ingestion during the year before the first symptom. Analgesic ingestion was not a risk factor. In the month before diagnosis only smoking was commoner in the DU group. The data indicate that smoking and alcohol ingestion are risk factors for DU.

Age Factors↗
PubMedDate not supplied

Perforated peptic ulcer in Hong Kong and New South Wales.

Direct comparisons of ulcer perforation rates and trends between countries have not been made in the past. Data on hospital admissions for perforated peptic ulcer during 1 January 1979 to 31 December 1985 were collected in Hong Kong (5868 perforations) and New South Wales, Australia (1669 perforations). Age and sex specific rates per 100,000 population were calculated. In Hong Kong, annual duodenal ulcer and gastric ulcer perforation rates were 13-16 and under two per 100,000 population respectively. In New South Wales, the corresponding rates were between three and four and under two per 100,000 population, respectively. The male:female ratios for duodenal ulcer perforation were consistently about 5:1 in Hong Kong and 2:1 in New South Wales, and for gastric ulcer perforation about 2:1 and 1:1, respectively. The incidence of perforation increased with age, and there was a statistically significant rise, over time, in duodenal but not gastric ulcer perforation rates in persons aged over 60 years in New South Wales; similar trends were seen in Hong Kong. Thus duodenal ulcer perforation occurs five times more commonly in Hong Kong than in New South Wales and this is largely accountable for by the higher rates of duodenal ulcer perforation in Chinese than in Australian males. Such geographical differences can best be explained by the occurrence of multiple aetiological mechanisms in ulcer perforation. Furthermore, there appears to be an increased susceptibility and an appreciable rising trend for duodenal ulcer perforation to occur in the elderly.

Adult↗