Eclampsia complicated by bilateral retinal detachments and abnormal eye movements.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to D Roberts.
Explore the source record for details and available documents.
OBJECTIVE: To determine reproductive sequelae in female rats after in utero and lactational dietary exposure to genistein. DESIGN: Experimental animal study. SETTING: University laboratory. ANIMAL(S): Sprague Dawley rats. INTERVENTION(S): Pregnant rats were fed control rat chow or rat chow incorporated with genistein (approximately 50 microg/d) beginning on day 17 of gestation and continuing until the end of lactation (postpartum day 21). Genistein-exposed female pups were divided into two groups on day 21. One group continued to receive a genistein-added diet (G70); the other group was changed to a control diet (Ex-G). At necropsy (days 21 and 70), blood and reproductive tissues were collected. MAIN OUTCOME MEASURE(S): Serum levels of gonadotropins and gonadal steroids and histopathologic examination of the ovaries. RESULT(S): The weight of the ovaries and uterus and serum levels of E2 and progesterone in genistein-exposed rats on day 21 (G21) were significantly reduced compared with control rats. On day 70, serum levels of E2, progesterone, LH, and FSH were similar in all groups. Atretic follicles and secondary interstitial glands were more common in G70 and Ex-G rats compared with control rats. Cystic rete ovarii was observed in some G70 and Ex-G rats. CONCLUSION(S): Our data indicate that in utero and lactational exposure to dietary genistein adversely affects reproductive processes in the adult female rat.
Two HPLC methods were developed: one for the quantitation of HBY 097 reverse transcriptase inhibitor and its metabolites M2 and M3 in human serum, and one for the quantitation of metabolite M5 in urine. The HPLC procedure for the quantitation of HBY 097 and its metabolites M2 and M3 in human serum involved protein precipitation with acetonitrile followed by automated on-line trace enrichment. The HPLC procedure for the analysis of metabolite M5 in urine involved enzymatic hydrolysis of urine with beta-glucuronidase to convert metabolite M5 (glucuronide of M3) to M3. Reverse phase chromatographic separation with gradient elution. UV detection at 335 nm, and internal standard were used to quantitate analytes in both procedures. The lower quantitation limits were 25 ng ml-1 for HBY 097 and metabolites M2 and M3 in serum, and 0.5 microgram ml-1 for the metabolite M5 in urine measured as metabolite M3 after hydrolysis. The HBY 097 and metabolite M3 concentrations were specific but metabolite M2 was semi-specific because the two diastereomers of M2 were not resolved by the present chromatographic procedure. Both procedures were applied to the quantitation of HBY 097 and its metabolites in serum and urine of HIV positive patients who were enrolled in a clinical study of drug safety and pharmacokinetics.
Molecular analyses based on plasmid profile typing and pulsed-field gel electrophoresis have defined a strain of Salmonella enterica serotype Anatum associated with the consumption of a particular brand of formula-dried milk responsible for an outbreak in late 1996/early 1997 involving 15 infants and 2 relatives in the UK, and 2 infants in France. The study has demonstrated the value of laboratory-based surveillance involving identification of the outbreak strain at the molecular level coupled with food microbiology and targeted epidemiological investigations, and has highlighted the importance of rapid communication and subsequent international collaboration through the European Union-funded Salm-Net salmonella surveillance network.
OBJECTIVE: To assess if hypnotherapy assists attempts at weight loss. DESIGN: Randomised, controlled, parallel study of two forms of hypnotherapy (directed at stress reduction or energy intake reduction), vs dietary advice alone in 60 obese patients with obstructive sleep apnoea on nasal continuous positive airway pressure treatment. SETTING: National Health Service hospital in the UK. MEASURES: Weight lost at 1, 3, 6, 9, 12, 15 and 18 months after dietary advice and hypnotherapy, as a percentage of original body weight. RESULTS: All three groups lost 2-3% of their body weight at three months. At 18 months only the hypnotherapy group (with stress reduction) still showed a significant (P < 0.02), but small (3.8 kg), mean weight loss compared to baseline. Analysed over the whole time period the hypnotherapy group with stress reduction achieved significantly more weight loss than the other two treatment arms (P < 0.003), which were not significantly different from each other. CONCLUSIONS: This controlled trial on the use of hypnotherapy, as an adjunct to dietary advice in producing weight loss, has produced a statistically significant result in favour of hypnotherapy. However, the benefits were small and clinically insignificant. More intensive hypnotherapy might of course have been more successful, and perhaps the results of the trial are sufficiently encouraging to pursue this approach further.
OBJECTIVES: (i) to describe the variation in a number of potential prescribing indicators across a large number of general practices, (ii) to determine whether particular indicators are associated with higher or lower overall prescribing costs, (iii) to determine how particular indicators are correlated with each other, (iv) to determine whether the indicators are stable over time. DESIGN: Observational study based on the analysis of PACT (Prescribing Analysis and Cost) data for general practices. SETTING: The Trent region of England. SUBJECTS: 809 general practices. MAIN OUTCOME MEASURES: Variations in a range of potential prescribing performance indicators; correlations between these indicators and NIC (net ingredient costs) per ASTRO-PU (Age, sex and temporary resident originated prescribing unit); change in indicators between the financial year 1994-5 and 1995-6. RESULTS: Wide variations were found between practices in a range of potential prescribing performance indicators. There were positive correlation (P < 0.001) between NIC per ASTRO-PU and indicators of relatively high cost prescribing within different therapeutic areas. There were negative correlations (P < 0.001) with indicators of relatively low cost prescribing. There were positive intercorrelations (P < 0.001) between indicators of relatively high cost prescribing. For most indicators there were significant changes (P < 0.001) in values between the two years. CONCLUSION: There are considerable variations between general practices in prescribing performance indicators and the indicators show changes over time. We have demonstrated correlations between different indicators that lend support to the idea that such indicators might act as proxies for more general prescribing patterns. However, most of the correlations we observed were not strong. Further research is needed into the development and use of indicators based on PACT data.
Crowding of Culex sitiens Wiedemann larvae was investigated to determine whether pupation was delayed by the presence of chemical factors in the water or by mechanical interference. As the larval density increased from 0.05 to 1.0 larvae per milliliter of water, the duration of larval development increased from 7.5 to 23.0 d and larvae mortality increased from 1.7 to 99.6%. At high larval densities (2 larvae per milliliter), the larvae did not pupate, but remained alive as 4th instars for at least 50 d, even after their abundance subsequently declined due to mortality. When not crowded, 80% of the larvae fed at the surface; the remainder fed mainly on the bottom (even at a depth of 35 cm). Removal of chemical retardants by changing the water daily increased pupation to 65% (compared with 4% in controls, in which the water was not changed), but this was less than the effect of reducing mechanical interference by increasing the surface area, which increased pupation to 98%. Therefore, the main density-dependent factor was mechanical interference during feeding, but prolonged development to 19 d showed that chemical retardants also were important. The chemical retardant was not stable, so that 2nd generation larvae reared in the same water were unaffected, but its effect was irreversible, because most crowded larvae moved to clean water and a lower density did not pupate.
A three-dimensional numerical modeling of airflow in the human pharynx using an anatomically accurate model was conducted. The pharynx walls were assumed to be passive and rigid. The results showed that the pressure drop in the pharynx lies in the range 200-500 Pa. The onset of turbulence was found to increase the pressure drop by 40 percent. A wide range of pharynx geometries covering three sleep apnea treatment therapies (CPAP, mandibular repositioning devices, and surgery) were modeled and the resulting flow characteristics were investigated and compared. The results confirmed that the airflow in the pharynx lies in the laminar-to-turbulence transitional flow regime and thus, a subtle change in the morphology caused by these treatment therapies can significantly affect the airflow characteristics.
Secretion of proteolytic and chitinolytic enzymes is a hallmark of infection processes of Metralhizium anisopliae in response to host (insect) cuticular signals. The regulation of these enzymes (subtilisin-like proteases [Pr1a and Pr1b], trypsin-like proteases [Pr2], metalloproteases, aspartyl proteases, aminopeptidase, and chitinases) and a hydrophobin was investigated by Northern analysis and/or enzyme assay. The production of each enzyme showed a differential expression pattern in response to ambient pH; enzymes were synthesized only at pHs at which they function effectively, irrespective of whether the medium contained an inductive cuticle substrate. Three aspartyl proteases (pH optimum, 3), and chitinase (pH optimum, 5) showed maximal accumulation at acidic pHs. The highest level of aminopeptidase (pH optimum, 7) was detected at pH 7. The highest levels of five metalloproteases (pH optima, ca. 7) were detected over the pH range 6 to 8. Two trypsins and several subtilisin-like Pr1 isoforms with pH optima of ca. 8 were produced only under alkaline conditions. Northern analysis of RNA species corresponding to seven cDNA sequences encoding proteases and chitinase confirmed that the ambient pH played a major role in gene expression of secreted proteins. Hydrophobin was expressed almost equally at pHs 5 and 8 but was not expressed at pH 3. During fungal penetration, the pH of infected cuticle rises from about 6.3 to 7.7. Consistent with pH regulation of enzyme production, serine and metalloproteases were produced in situ during infection, but no production of aspartyl proteases was found. We propose that the alkalinity of infected cuticle represents a physiological signal that triggers the production of virulence factors.
OBJECTIVE: To determine the efficacy and safety of trained cardiac technicians independently performing treadmill exercise stress tests as part of the assessment of patients with suspected angina pectoris. DESIGN: Retrospective comparison of 250 exercise tests performed by cardiac technicians and 225 tests performed by experienced cardiology clinical assistants (general practitioners who perform regular NHS cardiology duties), and consultant cardiologists over the same time period. SETTING: Regional cardiac centre with a dedicated cardiac chest pain clinic. PATIENTS: All patients were referred by their general practitioners with a history of recent onset of chest pain, which was suspected to be angina pectoris. OUTCOME MEASURES: Peak workload achieved, symptoms, indications for termination, complications. RESULTS: The diagnostic yield of technician supervised tests (percentage positive or negative) was similar to that of medically supervised tests (76% v 69%, NS). The average peak workload achieved by patients was less by 1.2 mets (p < 0.005). This was probably due to more tests being terminated earlier due to chest pain and ST segment depression in the technician group compared with doctors (10% and 16% v 5% and 11% respectively, p = 0.06 and 0.07). One patient in the technician supervised group developed a supraventricular tachycardia during the recovery phase of the exercise test. CONCLUSIONS: Technician supervised stress testing is associated with a high diagnostic rate and low complication rate in patients with suspected ischaemic heart disease. Its efficacy is comparable to tests supervised by experienced doctors and its use should be encouraged.
Increased bone turnover is a sequel of spinal cord injury (SCI) and predisposes to a number of clinically relevant complications, including osteoporosis and fractures. There are limited data available regarding the changes in modern markers of bone metabolism after SCI. We report a 6-month longitudinal follow-up of biochemical markers of bone metabolism (free and total deoxypyridinoline, total pyridinoline, N-telopeptide, osteocalcin, and total alkaline phosphatase) and bone mineral densitometry in 30 subjects with acute SCI. Markers of bone formation showed only a minor rise, remaining within the reference range. In contrast, markers of bone resorption showed a significant rise after acute SCI, peaking around weeks 10-16, with values up to 10 times the upper limit of normal. Paired bone mineral densities (n = 11; on the average, determined 14 weeks apart) showed no change at the hip, lumbar spine, or radius, but demonstrated a decrement in the entire lower limbs. changes in biochemical markers of bone formation and resorption were comparable in patients with quadriplegia and paraplegia, except for a greater increase in quadriplegics in pyridinoline, expressed as a percentage of baseline. In conclusion, a marked increase in bone resorption and modest changes in bone formation occur after SCI, and possibly increased bone resorption occurs in quadriplegia.
Our aim was to assess the outcome of pregnancies where oligohydramnios, defined by a published gestational reference range for amniotic fluid index, was the only abnormal finding at third trimester scan, and all other ultrasound parameters including biometry were within normal limits at initial scan. A retrospective case-control study was performed at The Liverpool Maternity Hospital. 103 pregnancies with reduced amniotic fluid index in the third trimester and apparently normal fetal growth profile ultrasonographically were identified from ultrasound reports throughout 1993. Pregnancies in the third trimester with normal amniotic fluid index on index scan were also identified from these reports and 103 were matched for parity, gestational age at delivery, mode of onset of labour, presentation at labour and medical conditions. Exclusion criteria were ruptured membranes, fetal abnormalities, estimated fetal weight below the fifth centile at index scan and multiple pregnancies. The outcome criteria were birthweight, Apgar scores at delivery, induction and emergency delivery for fetal reasons and admission to Neonatal Intensive Care Unit. Statistical analysis was performed by Fisher's exact test and Gart's odds ratio. Compared with controls, pregnancies in the reduced liquor group had a higher number of babies below the 5th centile (odds ratio 5.2, 95% confidence interval 1.6 to 22), a higher risk of induction for fetal reasons (odds ratio 34.4, 95% confidence interval 5.35 to 1425.5) and admission to Neonatal Intensive Care Unit (odds ratio 9.77, 95% confidence interval 1.3 to 432). Any observed difference in the need for emergency delivery due to fetal reasons was not clinically significant (odds ratio 2.16, 95% confidence interval 0.77 to 6.6) The definition used for oligohydramnios used in this study appears to identify a group of babies with a fourfold risk of low birthweight and a high risk of admission to the Neonatal Intensive Care Unit and induction of labour for fetal reasons. This would suggest that pregnancies with isolated oligohydramnios require some form of fetal monitoring and further prospective studies are required to determine the most appropriate method.
Information about limb positions and movements consists of input from visual, vestibular, cutaneous, muscular, tendinous and joint receptors, but the relative contribution from each type and location of receptors is not known. The aim of this study was: a) to measure the contribution from visual control on extremity function, as measured with a one-leg hop test in healthy persons, in patients with an asymptomatic ACL injury, after non-operative treatment and in patients with a stable knee after an ACL reconstruction, b) to investigate if there was any relation between proprioception from the extremity, as measured with the threshold for detecting passive motion of the knee, and the one-leg hop test with a gradual decrease in visual control. There was a decrease in hop-length when the subjects were deprived of visual control that was significant when the dominant eye or both eyes were blinded, both in the 2 patient groups and the reference population. The magnitude of the length reduction did not differ between the groups or between injured and healthy limbs. In all 4 threshold tests performed as a measure of peripheral proprioception, a stronger relation to hop-length was recorded for the blinded hop than with full visual control in the patients with nonoperated ACL injuries. The coefficients of correlation between hop-length and the proprioceptive recordings in the injured limb were of the same magnitude as on the healthy side.
Explore the source record for details and available documents.
BACKGROUND: The extended use of cardiopulmonary bypass (CPB) in cardiac surgery is limited because of damage to blood which in adults has been assessed by alterations in blood cell rheology. Blood trauma assessment in children is difficult because of the restrictions in sample volume and frequency but needs to be established from time to time in order to study the tolerance to new surgical and extracorporeal techniques. MATERIALS AND METHODS: Fourteen pediatric patients undergoing cardiac surgery with CPB for congenital heart disease corrections were studied. Whole blood, red blood cell and white blood cell rheology (filterability) were monitored before, during and after CPB using the St. George filtrometer that used small amounts of blood. RESULTS: The results showed that all the rheologic parameters were altered during the blood trauma of CPB and were outside the reference values before, during and after CPB. CONCLUSIONS: This suggested that blood cell rheologic disturbances did not recover soon after CPB and this may be of interest in long term follow-up to understand responses and recovery patterns to disease and interventions associated with pediatric heart surgery using CPB.
The standard method for counting Escherichia coli in live bivalve molluscs is labour intensive and takes three days to obtain a result. Modifications to the standard method were investigated in a collaborative trial conducted in five centres. No significant difference was found between results based on the presence of acid at 24 hours (h) in first stage tests and those based on the presence of acid and gas after 48 h (standard method). The use of the chromogenic medium BCIG (5-bromo-4-chloro-3-indolyl-beta-D glucuronide) agar incubated at 44 degrees C to confirm first stage tests was also found to give equivalent results to conventional confirmation tests. The preferred, modified method removes the presence of gas as a criterion of detection, uses a chromogenic agar medium to confirm the presence of E. coli, and gives results within 48 h. A distribution of simulated samples and selected strains of E. coli to other laboratories using the PHLS external quality assurance scheme for shellfish found no significant difference between results obtained by the standard and modified methods.
OBJECTIVE: The study was designed to measure dynamic visual acuity (DVA) during head movement as an assessment of the functional impact of vestibular deficits. STUDY DESIGN: The study design was a prospective, clinical study. SETTING: The study was performed in a tertiary, ambulatory referral center. PATIENTS: Forty-two normal subjects, 29 patients with unilateral vestibular loss, and 26 patients with bilateral vestibular hypofunction who were 19-87 years of age were examined. INTERVENTION: Diagnostic intervention was performed. MAIN OUTCOME MEASURE: Main outcome measures included the reliability, sensitivity, and specificity of a computerized test that measures visual acuity during head movement in normal subjects and in patients with vestibular deficits. RESULTS: The computerized DVA test was reliable in both normal subjects (intraclass correlation coefficient [ICC] r=0.87) and in patients with vestibular deficits (ICC r=0.83). The sensitivity of the DVA test was 94.5% and the specificity was 95.2%. The positive predictive value (individuals who test positive on the DVA test who will have a vestibular deficit) was 96.3%. The negative predictive value (individuals who test negative on the DVA test who will not have a vestibular deficit) was 93%. CONCLUSIONS: The computerized DVA test is reliable and is able to distinguish among normal subjects and patients with vestibular deficits.
We have compared the adhesion of Plasmodium falciparum-infected erythrocytes to human dermal microvascular endothelial cells (HDMEC) and human umbilical vein endothelial cells (HUVEC) and have assessed the relative roles of the receptors CD36 and intercellular adhesion molecule-1 (ICAM-1). HUVEC (a cell line that expresses high levels of ICAM-1 but no CD36) mediate low levels of adhesion, whereas HDMEC (which constitutively express CD36) mediate high levels of adhesion even before ICAM-1 induction ICAM-1 expression leads to yet greater levels of adhesion, which are inhibited both by anti-ICAM-1 and CD36 mAbs, despite no increase in the expression of CD36. The results indicate the presence of a substantial population of infected cells that require the presence of both receptors to establish adhesion. Synergy between these receptors could be demonstrated using a number of parasite lines, but it could not be predicted from the binding of these same parasite lines to purified ICAM-1 and CD36. This phenomenon could not be reproduced using either purified receptors presented on plastic, or formalin-fixed HDMEC, suggesting that receptor mobility is important. This is the first study to demonstrate receptor synergy in malaria cytoadherence to human endothelial cells, a phenomenon necessary for parasite survival and associated with disease severity.