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Biomedical subjects

P Royston

Publications and source records attributed to P Royston.

At least 73 records · Page 4Linked to original sources
PubMed1990

Maternal smoking habits and Down's syndrome.

Two series of pregnancies were studied to investigate the relationship between maternal smoking and the risk of fetal Down's syndrome. In the first series, ascertained in the 1960s, in which smoking habits were determined after the outcome of pregnancy was known, the proportion of smokers (47 per cent) among the 461 women whose pregnancies ended in the birth of an infant with Down's syndrome was similar to that in the 461 controls (46 per cent) who had pregnancies affected by other congenital disorders. In the second series, ascertained between 1973 and 1984, smoking habits were determined by measurement of cotinine in antenatal serum samples that were routinely collected and stored or, if a serum sample was not available, from information in the antenatal notes. In this series, the proportion of smokers (14 per cent) among the 91 women who had pregnancies associated with Down's syndrome was lower than that among 413 controls (19 per cent), though this was not statistically significant. Collectively, our results provide no evidence for an association between fetal Down's syndrome and smoking. Other published studies found a deficit of smokers among women who had pregnancies associated with Down's syndrome. This may be partly due to some studies not taking adequate account of maternal age (older women are more likely to have had a Down's syndrome pregnancy but are less likely to be smokers) and partly due to the greater tendency for positive findings to be published than negative ones.

Adult↗
PubMed1990

Novel screening strategies for early ovarian cancer by transabdominal ultrasonography.

Data collected during a prospective study to assess the efficacy of detecting early ovarian cancer by transabdominal ultrasonography have been used to refine and extend the screening procedure. The analysis was based on results from 5479 self-referred asymptomatic women, who were scheduled to undergo three annual screens consisting of one or more ultrasound scans. A positive result (based mainly on the presence of abnormal morphology) was obtained at 338 screens (326 women). Five patients with primary ovarian cancer (four stage 1a, one stage 1b; two at screen 1, three at screen 2) were identified (prevalence 0.09%). The apparent detection rate was 100% and the false-positive rate (FPR) was 3.5% at screen 1 and 2.3% overall. The use of abnormal morphology, or the maximum ovarian volume (MOV) greater than 96th centile as alternative criteria for a positive screen result, together with a defined volume change at rescan (VC) would give a FPR of 3.1% at screen 1 and 2.0% overall. The use of abnormal morphology alone at scan 1 and VC at rescan would give an overall FPR of 1.6%. The odds that a positive screen result would indicate the presence of an ovarian mass, a benign tumour, any ovarian cancer or primary ovarian cancer would be about 4 to 1, 2 to 1, 1 to 26, and 1 to 50 respectively. The results provide a more rational basis for the application and development of screening procedures for early ovarian cancer in both pre- and post-menopausal women.

Adolescent↗
PubMed1989

Transabdominal ultrasound screening for early ovarian cancer.

OBJECTIVE: To assess the value of ultrasonography in a screening procedure for early ovarian cancer. DESIGN: Prospective study of at least 5000 self referred women without symptoms of ovarian cancer. Each woman was scheduled to undergo three annual screenings (consisting of one or more scans) to detect grossly abnormal ovaries or non-regressing masses. SETTING: The ovarian screening clinic at King's College Hospital, London. SUBJECTS: 5479 Self referred women without symptoms (aged 18-78, mean age 52). INTERVENTIONS: Women with a positive result on screening were referred for laparoscopy or laparotomy, or both. MAIN OUTCOME MEASURES: Findings at surgery and from histology of abnormal ovaries. RESULTS: A total of 14,594 screenings (15,977 scans) were performed. A positive result was obtained at 338 screens (2.3%) comprising 326 subjects (5.9%). Five patients with primary ovarian cancer (four stage Ia, one stage Ib; two at first screening three at second) were identified (prevalence 0.09%). An additional four patients had metastatic ovarian cancer (three at first screening, one at second). The apparent detection rate was 100%. It was not possible to differentiate between the ultrasonic appearance of early malignant and benign tumours. The rate of false positive results for primary ovarian cancer was 3.5% at the first screening, 1.8% at the second, and 1.2% at the third. Overall the rate of false positive results was 2.3%; the specificity was 97.7% and the predictive value of a positive result on screening was 1.5%. The odds that a positive result on screening indicated the presence of an ovarian tumour, any ovarian cancer, or primary ovarian cancer were about one to two, one to 37, and one to 67 respectively. CONCLUSION: Ultrasonography can be used to screen women without symptoms for persistent ovarian masses that will include early ovarian cancer.

Adolescent↗
PubMed1989

An evaluation of the BIOSELF 110 fertility indicator.

The BIOSELF 110 is a hand-held, non-invasive electronic instrument that measures basal body temperature and cycle length, and automatically identifies the fertile and infertile phases of the menstrual cycle with flashing red light and green light signals, respectively. The device was evaluated in 77 cycles from 33 ovulatory women in Kuala Lumpur, Malaysia. Ultrasound monitoring of maximum follicular diameter (MFD) and urinary LH measurements with Ovustick were used as reference methods to estimate the time of ovulation and the fertile period. Based on the MFD day, the BIOSELF correctly identified the entire fertile period, and at least four fertile days, in 89% and 94% of the cycles studied, respectively. The mean duration of the fertile period as determined by the number of flashing red light days was 11.0 days (SD 2.9). The device correctly identified the onset of the postovulatory infertile phase in 94% of cycles, with a mean duration of about 10 (green light) days. The results were similar using the LH peak day as the reference method. The mean interval from the onset of the fertile period (first flashing red light day) to the MFD day was 6.9 days (SD 2.6), and from the MFD day to the end of the fertile period, 3.1 days (SD 2.2). The BIOSELF 110 showed itself to be a reliable device for identifying the fertile and infertile phases of the menstrual cycle and, thus, should be a useful aid for couples seeking pregnancy. Prospective clinical trials are underway to assess the contraceptive effectiveness of the device.

Adult↗
PubMed1989

Ultrasound fetal femur length measurement in the screening for Down's syndrome.

The fetal femur length determined by an ultrasound examination at between 13 and 39 weeks gestation in 83 pregnancies associated with Down's syndrome was statistically significantly less than the expected value for pregnancies with the same biparietal diameter examined in the same ultrasound department (P less than 0.0001). Expected values were based on linear regressions of femur length on biparietal diameter in 1340 control pregnancies from 27 ultrasound departments. The median value for the affected pregnancies was 0.94 times the expected value (95% CI 0.92 to 0.97). Eleven per cent of affected and 1.4% of control pregnancies had values less than or equal to 0.85 times the expected. The reduction in femur length in affected pregnancies was not related to biparietal diameter or to maternal age. Fetal femur length may be useful as an ancillary screening variable in the antenatal screening for Down's syndrome.

Down Syndrome↗
PubMed1989

Characteristics of persistent ovarian masses in asymptomatic women.

Persistent ovarian masses have been found in a substantial proportion of 5479 self-selected asymptomatic women who were screened for early ovarian neoplasia. Each woman was scheduled to undergo three ultrasound screens (consisting of 1-12 scans) to detect regressing and non-regressing masses. A total of 14,594 screens (15,977 scans) was performed. The average interval between successive screens was 595 days (range 214-1134 days). Overall, 650 screens (4.4%; 10.1% of women) produced a positive result which became negative with successive scans (four times more frequently in pre- than naturally postmenopausal women), and 338 screens (2.3%; 5.9% of women) had a final positive result (at least one ovary that was grossly abnormal or contained a persistent mass). Biopsies were taken from 336 ovaries (89% of total, 271 women). Overall, 134 tumour-like conditions and 119 benign tumours were identified. The detection rate of tumour-like conditions was 1.5 times higher in premenopausal than naturally postmenopausal women, whereas the proportion of tumours to normal ovaries was similar in both groups. Overall, 51% of tumour-like conditions and 70% of all tumours were detected at screen 1. Four women had metastatic ovarian cancer (three at screen 1, one at screen 2; two were bilateral). Five women (0.1%) had a primary malignant tumour (two at screen 1, three at screen 2; four were stage 1a and one was stage 1b). All women are being monitored to obtain additional information about the significance of the findings.

Female↗
PubMed1988

Maternal serum screening for Down's syndrome in early pregnancy.

The possibility of improving the effectiveness of antenatal screening for Down's syndrome by measuring human chorionic gonadotrophin concentrations in maternal serum during the second trimester to select women for diagnostic amniocentesis was examined. The median maternal serum human chorionic gonadotrophin concentration in 77 pregnancies associated with Down's syndrome was twice the median concentration in 385 unaffected pregnancies matched for maternal age, gestational age, and duration of storage of the serum sample. Measuring human chorionic gonadotrophin in maternal serum was an effective screening test, giving a lower false positive rate (3%) at a 30% detection rate than that for maternal age (5%) and the two existing serum screening tests, unconjugated oestriol (7%) and alpha fetoprotein (11%). The most effective screening results were obtained with all four variables combined; at the same 30% detection rate the false positive rate declined to 0.5%. The new screening method would detect over 60% of affected pregnancies, more than double that achievable with the same amniocentesis rate in existing programmes (5%), and could reduce the number of children born with Down's syndrome in the United Kingdom from about 900 a year to about 350 a year.

Chorionic Gonadotropin↗
PubMed1988

Glucose homeostasis in the newborn. Effects of oral feeding on response to fasting and intravenous glucose infusion in neonatal piglets.

The effect of oral feeding on the response to fasting and to an intravenous glucose infusion was investigated in neonatal piglets. Piglets, which had received no food at birth, reduced both their rates of glucose appearance and glucose utilisation (at 24 h: 43 +/- 3.5 mumol/min in previously fed piglets and 28 +/- 6 mumol/min in fasted piglets; at 48 h: 45 +/- 3.5 mumol/min in previously fed piglets and 25 +/- 5 mumol/min in fasted piglets). This reduction in glucose turnover was not associated with a fall in plasma glucose concentration, and all groups of piglets were normoglycaemic at the start of the study. An intravenous infusion of glucose (100 mumol/kg/min) resulted in suppression of hepatic glucose output and an increase in the glucose utilisation rate. Piglets, which had received no food at birth, had lower absolute rates of glucose utilisation throughout the period of infusion. The present study indicates that major changes in glucose turnover rates may occur prior to these being reflected in changes in blood glucose concentration. The results also indicate that oral feeding affects both steady-state glucose turnover and the response to an intravenous glucose infusion.

Administration, Oral↗
PubMed1985

The effects of long-acting pinacidil on intra-arterial blood pressure.

We have tested the efficacy of a new long-acting preparation of pinacidil, an arterial vasodilator, using continuous intra-arterial ambulatory blood pressure recording. An acute dose produced a measurable effect lasting for 12 h. The duration of this effect was less during chronic twice daily drug administration. Side effects were common, causing two out of nine patients to withdraw from the study. Tilt testing produced no postural hypotension and there was no evidence of rebound hypertension on the withdrawal day.

Antihypertensive Agents↗
PubMed1983

Prognostic value of tumour thickness in cutaneous malignant melanoma.

The relation between survival and histological features in 91 patients with malignant melanoma was studied and the results were analysed by Clayton's method for interpretation of censored survival data. There was a significant correlation between tumour thickness and survival. The risk of dying from malignant melanoma after 10 years of follow up was less than 15% if the primary tumour was less than 1.5 mm thick but more than 80% if the lesion was thicker than 8 mm. The type of melanoma, level of invasion, mitotic rate, and presence of ulceration also correlated with survival, but these variables are related to tumour thickness.

Adult↗
PubMed1981

The effect of meal frequency and protein concentration on the composition of the weight lost by obese subjects.

1. Nitrogen balance, weight loss and resting metabolic rate were measured in thirty-eight obese inpatients on 3.4 MJ (800 kcal)/d diets over 3 weeks. 2. All subjects were fed on 13% protein-energy in three meals/d for the first week. 3. In weeks 2 or 3, using a cross-over design, ten subjects were fed on 15 or 10% protein-energy as three meals/d; fourteen subjects were fed on five or one meal/d with 13% protein-energy; and fourteen subjects were fed on 15% protein-energy as five meals/d or 10% protein-energy as one meal/d. 4. N loss was least on the high-protein week and frequent-meal week: the largest difference was found when these effects were combined (P less than 0.001). 5. When protein-energy was held constant at 13% N loss decreased significantly (P less than 0.01) between week 2 and 3, but when the protein-energy was manipulated there was no significant N conservation in the third week. This suggests that the protein:energy value is more important than meal frequency in the preservation of lean tissue. 6. Weight loss was also least on the 'high-protein' week and 'frequent-meal' week, but this result reached significance only when the effects were combined (P less than 0.05). 7. Resting metabolic rate decreased with time but was not significantly altered by the dietary regimens. 8. Therefore, during the first 3 weeks at an intake of 3.4 MJ/d, a diet with a high-protein concentration, fed as frequent small meals, is associated with better preservation of lean tissue than an isoenergetic diet with lower-protein concentration fed as fewer meals. There was no evidence that meal frequency or protein concentration affect the rate of fat loss.

Adolescent↗
PubMed1980

Factors influencing the composition of the weight lost by obese patients on a reducing diet.

1. Weight loss, resting metabolic rate and nitrogen loss were measured in forty obese inpatients on reducing diets. 2. Five subjects ate 3.55 MJ/d for 6 weeks (Expt 1). Twenty-one subjects ate 4.2 MJ/d for the first week, 2.0 MJ/d for the second week and 4.2 MJ/d for the third week (Expt 2). Fourteen subjects ate 3.4 MJ/d for the first week and then 0.87 MJ protein or carbohydrate for the second or third weeks, using a cross-over design for alternate patients (Expt 3). 3. Patients in Expt 1 had highest weight loss and N loss in the first 2 weeks, but adapated to the energy restriction over the remaining weeks. On average subjects were in N balance at the end of the study. 4. In Expt 2 patients eating 2.0 MJ/d in week 2 showed increased weight loss compared with week 1. N loss was not raised but it failed to decrease as it had in Expt 1. Weight loss and N loss were reduced on return to 4.2 MJ/d for a third week. 5. In Expt 3 patients eating 0.87 MJ protein showed significantly more weight loss and less N loss than patients eating 0.87 MJ carbohydrate. 6. Resting metabolic rate decreased with time on the low-energy diet, but the manipulations of energy or protein content did not significantly affect the pattern of decrease. 7. Both weight loss and N loss were greater the lower the energy intake, and both decreased with time. Diets with a high protein:energy value give a favourable value for N:weight loss at each level of energy intake.

Adolescent↗
PubMed1980

The long-term effect of energy intake on salivation, hunger, and appetite ratings, and estimates of energy intake in obese patients.

The relationship between salivation, hunger, appetite, and estimates of energy intake was examined in female obese inpatients undergoing a course of weight reduction. On a constant low-energy intake (800 kcal/day) salivation, hunger, and appetite scores all declined. Estimates of energy intake did not. Sixteen different subjects were fed 1000 kcal/day for seven days, 500 kcal/day for seven days, and 1000 kcal/day for seven days. After acclimatization to the diet for a minimum of five days, salivation was directly related to energy intake; hunger and appetite ratings did not change significantly; and estimates of energy intake were sensitive to the decrease but not increase in energy intake. The limitations of each method of assessment are discussed.

Adolescent↗