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Biomedical subjects

P Prescott

Publications and source records attributed to P Prescott.

At least 37 records · Page 2Linked to original sources
PubMed1994

A comparative study of several antibiotic formulations using a design based on a combination of balanced incomplete blocks and Latin squares.

A practical application of an experimental design, suitable for the comparison of several treatments, and based on combining balanced incomplete blocks and Latin squares balanced for carryover effects, is presented in the context of comparing a number of paediatric antibiotic formulations for taste, smell and colour. The recommended designs originally suggested by Patterson, have the advantage of balanced incomplete blocks, in that a single trial may be used to compare a larger number of treatments than may reasonably be given to any individual subject. In addition, the incorporation of suitably chosen Latin squares allows for assessment of any effect of order of presentation of the treatments and for any simple first-order carryover effect of one treatment into the following treatment period. Inclusion of such effects in the overall analysis could result in the reduction of bias in the comparisons of the treatments.

Analysis of Variance↗
PubMed1993

High dose Nutrizym 22 in cystic fibrosis.

New high dose pancreatic enzyme preparations could be potentially helpful to cystic fibrosis (CF) patients. The purpose of this study was to compare the efficacy of the new high dose pancreatic enzyme preparation, Nutrizym 22 with the standard preparation Nutrizym GR. Twenty-five CF children (aged 7-16 years) entered the study and 22 completed it; 3 did not, due to non-compliance. All were taking Nutrizym GR for at least 2 weeks before entering the study. A randomised double blind, crossover method using standard Nutrizym GR or double strength Nutrizym 22 capsules was carried out over two consecutive 14-day periods. Crossover analyses of variance showed no statistically significant differences in actual weight gain, appetite, abdominal pain, stool consistency or faecal fat during the prestudy and study periods. It is concluded that half the capsule numbers of the high strength preparation are just as effective as the standard capsule dosage.

Adolescent↗
PubMed1991

An open, randomised, parallel group study of lactulose versus ispaghula in the treatment of chronic constipation in adults.

The efficacy, tolerance and acceptability of lactulose (Duphalac) and ispaghula (Fybogel Orange) were assessed in the treatment of chronic constipation in adults. In an open, prospectively randomised, parallel group study, 124 patients with a history of constipation for more than three weeks were treated with either 15 ml bd of lactulose (increasing to 60 ml daily if necessary) or one sachet bd of ispaghula. Over the four-week treatment period both treatments were shown to be effective, and numbers of concurrent effects were similar between the two groups. Differences were demonstrated with regard to acceptability in favour of lactulose.

Bicarbonates↗
PubMed1990

Effect on plasma lipids and lipoproteins of postmenopausal oestrogen therapy with added dydrogesterone.

In a prospective, randomized, cross-over study, 14 postmenopausal women completed 9 months of treatment with conjugated equine oestrogens, 1.25 mg daily. Seven women added dydrogesterone 20 mg daily for 12 days during months 2, 3 and 4, and then 10 mg daily for an identical time in months 5, 6 and 7. The other seven women added the two dydrogesterone doses in reverse sequence. No dydrogesterone was taken during months 8 and 9. Lipids and lipoproteins were measured before treatment and at the end of months 4, 7 and 9. Lipids were also estimated in an untreated (reference) group of eight postmenopausal women on two occasions 6 months apart; these showed significant changes in HDL2- and HDL3-cholesterol. In the treatment group, HDL-cholesterol and apolipoprotein (apo) A1 were significantly higher and LDL-cholesterol and apo B were significantly lower at months 4, 7 and 9 compared with baseline values. Triglyceride levels were increased significantly over baseline values, but remained within the normal range. No significant differences between the two dydrogesterone doses were observed on any lipid and lipoprotein fraction, nor were there any differences between the oestrogen-only and oestrogen/dydrogesterone treatment phases. Dydrogesterone appears to cause little, if any, lipid and lipoprotein changes and assessment in a larger population of postmenopausal women is warranted.

Dydrogesterone↗
PubMed1990

Endometrial, physical and psychological effects of postmenopausal oestrogen therapy with added dydrogesterone.

Sixteen postmenopausal women receiving conjugated equine oestrogens 1.25 mg/day, continuously, were randomly allocated to add dydrogesterone 20 mg/day for 12 days each calendar month for 3 months and then 10 mg/day in an identical fashion for a further 3 months, or to receive the dydrogesterone doses in reverse sequence. The effects of the two dydrogesterone doses on endometrial histology, vaginal bleeding, and the symptomatic and psychological status were compared. Endometrial samples were obtained around day 10 of progestogen addition. Dydrogesterone, 20 mg, induced uniform, late secretory transformation in all samples; with 10 mg one sample showed mixed early and late secretory features and another demonstrated late secretory changes associated with atypical hyperplasia. Both dydrogesterone doses induced an acceptable withdrawal bleed; most bleeding episodes were 'spotting' or normal in amount, and heavy bleeding was reported infrequently. There was one episode of breakthrough bleeding. There were no differences in bleeding patterns between the two dose regimens. Anxiety, and the physical and psychological status were significantly improved after 3 months of therapy. Significant benefits on depression were observed less clearly. There were no differences between the two dydrogesterone doses on anxiety, depression and the physical and psychological status, and, overall, the addition of the progestogen did not antagonize oestrogen benefits.

Affective Symptoms↗
PubMed1990

Lactulose in the treatment of symptomatic diverticular disease: a comparative study with high-fibre diet.

OBJECTIVE: To compare the efficacy and tolerance of lactulose (Duphalac) and high-fibre diet in the treatment of symptomatic diverticular disease. DESIGN: Prospectively randomised, parallel groups study over 12 weeks. Patients were seen by their clinician for an initial assessment and then at weeks 4, 8 and 12. SETTING: Hospital out-patients in the United Kingdom. PATIENTS: Forty-three patients with a confirmed diagnosis of diverticular disease were entered into the study. INTERVENTION: Patients were prospectively randomised to receive lactulose (15 ml bd) or high-fibre diet (30-40 g daily) for 12 weeks. MEASUREMENTS AND RESULTS: Data were collected using diary cards and physicians' assessments. Bowel frequency and stool consistency improved similarly with both treatments. Pain on bowel movement improved with both treatments in respect of frequency (lactulose: P = 0.017, fibre: P = 0.084) and severity (lactulose: P = 0.028, fibre: P = 0.043). Abdominal pain also improved with both treatments in respect of frequency (lactulose: P = 0.0015, fibre: P = 0.022) and severity (lactulose: P = 0.009, fibre: P = 0.028). Nine patients on lactulose and 12 on fibre reported treatment-emergent symptoms, of which none was serious. CONCLUSIONS: Lactulose and high-fibre diet were both shown to be effective in the treatment of diverticular disease, with some differences in favour of lactulose.

Adult↗
PubMed1988

Premenstrual syndrome. A double-blind cross-over study of treatment with dydrogesterone and placebo.

A double-blind, cross-over, placebo-controlled study of dydrogesterone (10 mg b.d.) in the treatment of premenstrual syndrome is described. Two groups of women were studied: secondarily referred hospital clinic patients, and self-referred patients. Only one-third of patients screened completed the study. All patients showed significant improvements in symptom scores during the course of the study, the only significant difference between placebo- and dydrogesterone-treated patients being an increase in frequency of breast tenderness and a decrease in pain with menstrual bleeding in the latter.

Adult↗
PubMed1986

A double-blind crossover study comparing betahistine and cinnarizine in the treatment of recurrent vertigo in patients in general practice.

A double-blind crossover study was carried out in general practice in 88 patients with peripheral vertigo of unknown origin to compare the efficacy and tolerance of 12 mg betahistine dihydrochloride and 15 mg cinnarizine. Patients were allocated at random to receive 2 tablets 3-times daily of one or other drug for 3 consecutive months before being crossed over to the alternative medication for a further 3 months. Severity of symptoms was assessed at 4-week intervals using the Clinical Global Impression scale and patients kept a record in a daily diary of the frequency and duration of attacks. Details were also recorded of any side-effects reported. The results were analyzed for 46 patients who completed the 6-month study period. Both drugs were shown to be equally effective in reducing the duration and severity of symptoms. Significantly fewer attacks of vertigo, however, occurred during betahistine therapy. Side-effects were the most common reason for dropping out whilst on cinnarizine (9 patients) and were complained of by 38 patients during the study (16 only when on betahistine, 19 only on cinnarizine, 3 whilst on both drugs). The most frequently reported were drowsiness or lethargy affecting 16 patients on cinnarizine and 7 on betahistine.

Aged↗
PubMed1984

Premenstrual syndrome: weight, abdominal swelling, and perceived body image.

One hundred forty-eight menstrual cycles were studied in 52 women, and in each cycle various parameters were measured to determine an objective means of assessing the syndrome. Daily mood assessment, body weight, plasma 17 beta-estradiol levels, and plasma progesterone levels were measured. The abdominal dimensions were measured in the lateral and anteroposterior diameters at the level of the umbilicus and 10 cm below; at the same time the same dimensions were measured as perceived by the patient. Mood score showed a marked increase during the premenstrual phase of each cycle. The symptom of bloatedness was marked during the premenstrual phase of the cycle. Despite these highly elevated scores for bloatedness there was no increase in body weight or the measured body dimensions in any plane. However, the patient's perception of body size did increase, and the discrepancy between the perceived body size and the actual body size (perception error) was significant.

Body Image↗
PubMed1981

The assessment of the symptoms of premenstrual syndrome and their response to therapy.

The symptoms of premenstrual syndrome should be rated daily, or at frequent intervals throughout the menstrual cycle. Self-rating is usually most feasible and separate rating of differing symptom groups is important, as symptoms differ in their response to therapy. Daily scores should be analysed to assess periodicity, either by subdividing the cycle into phases or by using the least mean square method of fitting sine waves. Standardized scores enable data to be compared across cycles. In a clinical trial it is important to include an untreated cycle to assess whether the subject has premenstrual syndrome and as a baseline with which to compare treated cycles. Allowance should be made for a carry-over effect and for high placebo response. One solution is to use a change-over design balanced for carry-over effects. The criteria used to define a patient should be stated.

Adolescent↗
PubMed1980

Sensitivity of a double-blind trial of ritodrine and placebo in twin pregnancy.

A critical examination is made of the results of a recently reported double blind trial comparing ritodrine and placebo. It is shown that interval estimates are more informative than p-values obtained from significance tests and that the trial involving 49 patients was insensitive to differences which could be clinically important. Contrary to the conclusions presented, the data suggest that further evaluation of the effects of ritodrine in twin pregnancies is necessary to clarify the situation.

Birth Weight↗
PubMedDate not supplied

Predicting the duration of the first stage of spontaneous labor using a neural network.

To create a neural network that predicts the length of the first stage of term labor. Two hundred patients with gestations > or = 36 weeks, in spontaneous active labor are the study group: 159 for training and 41 for testing; 4 training set patients had second-stage cesarean section for obstructed labor. The network is designed with Brainmaker MacIntosh 1.0 (California Scientific Software). Inputs are uterine activity, estimated fetal weight, position, station, and gestational age; maternal parity, age, height, weight, membrane status, and cervical dilatation. Actual first stages are regressed on those predicted by the network or by a standard partogram set. Differences between actual first stage lengths and those predicted by the neural network or partogram are compared with t-tests; while the proportions of first stages accurately predicted within 1 or 2 h are compared for both methods with chi-square tests. The network trained in 4 h (1388 runs) to a 0.15 tolerance. The network predictions have significantly higher correlation (r = 0.88) than do standard partograms (r = 0.35) with actual first stage durations. Mean differences between predicted and actual first stages are significantly lower for network output than with partograms; these differences increased with first stages exceeding 3 h; 100% of trained network values are within 2 h of actual first stage length. The network performs similarly for a new set of 41 previously unseen labors. This neural network predicts the length of the first stage of spontaneous labor and uses inputs readily available to obstetricians. It outperforms typical partograms for estimating this important feature of normal labor. Future application for intrapartum prognosis could be based on this successful design.

Artificial Intelligence↗
PubMedDate not supplied

Effect of intensive insulin therapy on progression of overt nephropathy in patients with type 1 diabetes mellitus.

OBJECTIVE: To assess the effects of chronic (long-term) intermittent intravenous insulin therapy (CIIIT) on the progression of overt nephropathy in patients with type 1 diabetes mellitus. METHODS: We undertook a retrospective longitudinal three-center study of 31 patients with type 1 diabetes mellitus and overt nephropathy, who were receiving intensive subcutaneous insulin therapy (four insulin injections daily) and weekly CIIIT. All study patients had follow-up consultations weekly for at least 12 months (mean duration, 37.0 +/- 4.6 months). Each patient had monthly hemoglobin A(1c) (by high-performance liquid chromatography) and semiannual creatinine clearance determinations. RESULTS: The hemoglobin A(1c) levels declined significantly from 8.6 +/- 0.6% to 7.6 +/- 0.3% (P = 0.0062) during the study period. The creatinine clearance remained essentially unchanged (from 46.1 +/- 3.0 mL/min per 1.73 m 2 at baseline to 46.0 +/- 3.9 mL/min per 1.73 m 2 at the end of the observation period, with an average annualized slope increase of 3.39 +/- 1.5 mL/min per year--no significant difference). CONCLUSION: The addition of CIIIT to intensive subcutaneous insulin therapy in patients with type 1 diabetes mellitus seems to arrest or appreciably reduce the progression of overt diabetic nephropathy, as well as substantially improve their glycemic control.

Journal Article↗
PubMedDate not supplied

Prevalence of osteoporosis in women: variation with skeletal site of measurement of bone mineral density.

OBJECTIVE: To determine retrospectively the prevalence of osteoporosis in a referral population of female patients and to compare the sensitivity for diagnosing osteoporosis by dual-energy x-ray absorptiometry (DXA) measurements of bone mineral density (BMD) at multiple skeletal sites. METHODS: We studied the data from 625 consecutive women (mean age, 57.3 +/- 13.9 years), who had been referred to our center for lumbar spine (anteroposterior [AP] and lateral region) and hip (femoral neck [FN], Ward's triangle [WT], trochanter, intertrochanteric region, and total hip) BMD measurements with use of DXA (Hologic QDR-2000) between June 1994 and July 1998. RESULTS: Osteoporosis (based on the World Health Organization definition--T-score of -2.5 or lower for BMD) was diagnosed by DXA at the following sites: AP spine in 21.7%, lateral spine in 43.2%, FN in 33.6%, WT in 49.1%, trochanter in 26.1%, intertrochanteric region in 25.9%, and total hip in 28.4% of study patients. Significant site differences were found in the prevalence of osteoporosis between the lateral and AP spine (P < 0.001), as well as between WT and the FN, trochanter, intertrochanteric region, and total hip (P < 0.001). In a subgroup of 71 women, forearm (ultradistal radius and radius 1/3 region) BMD results indicated low sensitivity for diagnosing osteoporosis, similar to that seen at the AP spine, trochanter, and intertrochanteric region. Not surprisingly, the prevalence of osteoporosis increased with advancing age (15.5% in patients younger than 50 years, in comparison with 59.6% in those older than 69 years of age). The frequency of misclassification of patients (osteoporosis at one site and normal BMD at another) with use of the seven measurement sites was 16.6% (104 of the 625 patients). CONCLUSIONS: For diagnosis of osteoporosis, DXA BMD measurements are significantly more sensitive at the lateral spine than at the AP spine, as well as at WT than at the FN, trochanter, intertrochanteric region, and total hip sites.

Absorptiometry, Photon↗