Biomedical subjects
Publications and source records attributed to N Cooper.
The synthesis and pharmacological profile of a novel series of potent and selective phosphodiesterase type IV (PDE IV) inhibitors is described.
A series of novel selective phosphodiesterase 4 (PDE4) inhibitors has been developed which displays activity both in vitro and in vivo. These compounds possess good selectivity for the catalytic site of PDE4 over the high affinity Rolipram binding site. In vivo studies demonstrate a reduced propensity to display the emetic side effects which are commonly observed with PDE4 inhibitors.
A survey of junior doctors in trusts in one English region found the majority did not know whether or not their post met Department of Health requirements on hours and conditions. Most did not know that average hours worked per week should not exceed 56. Most of the acute trusts had groups to implement these New Deal regulations. But almost two-thirds of junior doctors were unaware of these. Ignorance of the New Deal by junior doctors and other NHS personnel could hamper accreditation of trusts.
OBJECTIVE: To determine whether a community based coronary heart disease health promotion project, undertaken over four years, was associated with changes in the prevalence in adults of lifestyle risk factors known to affect the development of coronary heart disease, and to estimate whether such an approach was cost effective. DESIGN: Prospective, comparative study of the effects of a health promotion intervention on coronary heart disease lifestyle risk factors, assessed by postal questionnaire sent to a randomly chosen sample, both at baseline and after four years. SUBJECTS: Intervention and control populations of adults aged 18-64 in Rotherham, both from areas with a high incidence of coronary heart disease and similar socioeconomic composition. MAIN OUTCOME MEASURES: Changes in prevalence of lifestyle risk factors between the control and intervention communities from 1991 to 1995. The effect of the intervention on certain lifestyle behaviours was evaluated using multiple logistic regression to model the proportion with a particular behaviour in the study communities as a function of age (18-40 or 41-64 years), sex, the year of observation (1991 or 1995), and area (intervention of control). RESULTS: 6.9% fewer people smoked and 8.7% more drank low fat milk in the intervention area, but no other statistically significant changes between the areas were detected. The estimated cost per life year gained was pounds 31. CONCLUSIONS: It is possible to have a cost effective impact on coronary heart disease lifestyle risk factors in a population of adults over four years using only modest resources.
Phosphodiesterase type 4 (PDE4) plays a major role in modulating the activity of virtually all cells involved in the inflammatory process. Inhibitors of this enzyme family display impressive anti-inflammatory and disease-modifying effects in a variety of experimental models. In this review, Mauro Teixeira, Robert Gristwood, Nicola Cooper and Paul Hellewell examine the capacity of PDE4 inhibitors to exert anti-inflammatory actions in vivo and discuss the potential of this class of drugs to take their place as novel therapeutic agents for a variety of inflammatory diseases.
BACKGROUND: 3'-Deamino-3'-(2-methoxy-4-morpholinyl)doxorubicin (FCE 23762, PNU 152243) is a highly lipophilic doxorubicin derivative which possesses potent in vitro and in vivo antitumor activity. Previous phase I studies had been conducted using a single bolus every 28 days. PATIENTS AND METHODS: We conducted a phase I study of FCE 23762 on a daily x3 every 28 days schedule. Thirty patients received 68 cycles of therapy at 5 dose levels (200-600 micrograms/m2/d). RESULTS: Prolonged neutropenia and thrombocytopenia were the dose-limiting toxicities. Other nonhematological toxicities included nausea and vomiting, anorexia, fatigue and transient elevations of serum creatinine and hepatic transaminases. No cardiac toxicity was demonstrated. There were no partial or complete antitumor responses. CONCLUSION: The recommended phase II dose using the schedule defined in this study is 500 micrograms/m2/dx3.
Activation of the classical complement pathway has been widely investigated in recent years as a potential mechanism for the neuronal loss and neuritic dystrophy characteristic of Alzheimer's disease (AD) pathogenesis. We have previously shown that amyloid beta peptide (A beta) is a potent activator of complement, and recent evidence suggesting that the assembly state of A beta is crucial to the progress of the disease prompted efforts to determine whether the ability of A beta to activate the classical complement pathway is a function of the aggregation state of the peptide. In this report, we show that the fibrillar aggregation state of A beta, as determined by thioflavin T fluorometry, electron microscopy, and staining with Congo red and thioflavine S, is precisely correlated with the ability of the peptide to induce the formation of activated fragments of the complement proteins C4 and C3. These results suggest that the classical complement pathway provides a mechanism whereby complement-dependent processes may contribute to neuronal injury in the proximity of fibrillar but not diffuse A beta deposits in the AD brain.
The elevation of intracellular cyclic AMP by phosphodiesterase (PDE)4 inhibitors in eosinophils is associated with inhibition of the activation and recruitment of these cells. We have previously shown that systemic treatment with the PDE4 inhibitor rolipram effectively inhibit eosinophil migration in guinea pig skin. In the present study we compare the oral potency and efficacy of the PDE4 inhibitors rolipram, RP 73401 and CDP 840 on allergic and PAF-induced eosinophil recruitment. Rolipram and RP 73401 were equally effective and potent when given by the oral route and much more active than the PDE4 inhibitor CDP 840. We suggest that this guinea pig model of allergic and mediator-induced eosinophil recruitment is both a sensitive and simple tool to test the efficacy and potency of PDE4 inhibitors in vivo.
A community health promotion project called Action Heart was undertaken in two electoral wards in Rotherham to try to change lifestyles of people. Schools were included within the project. Coronary heart disease lifestyle risk factors were measured at baseline and after a three year period in the intervention area and a similar control area. Lifestyle factors in schoolchildren were measured separately from adults using a different instrument. The post intervention survey of adults and economic evaluation demonstrated that Action Heart had achieved cost-effective estimated health gains. In the schoolchildren however, a mixture of positive and negative risk factor changes in both areas was demonstrated. Significant changes in lifestyle risk factors in schoolchildren were not elicited using this approach. The possible reasons for the lack of impact on lifestyle risk factors in schoolchildren are examined and the implications for further work explored.
Cyclic-GMP, which plays a pivotal role in visual transduction in the vertebrate retina, is synthesized by guanylate cyclase. The purpose of this study was to localize a rod outer segment-derived particulate guanylate cyclase (ROS-GC) to the retina of several species that have different populations of rods and cones. A rabbit antibody was raised against a synthetic peptide, corresponding to the sequence A107-L125 of bovine ROS-GC. Western blot analysis showed a single immunoreactive band at about 115 kDa with bovine rod outer segments but not with human rod outer segments. Light microscopic immunocytochemistry of tissue sections revealed immunoreactivity in the outer segment layer and in the outer and inner plexiform layers. The rod-rich rat retina showed uniform immunolabeling of outer segments; the cone-containing cat retina showed heavily labeled cone outer segments and lighter labeling of rod outer segments; the cone-rich chicken retina showed a uniformly and intensely labeled outer segment layer. Preincubation of the primary antibody with the peptide completely blocked antibody binding. Electron microscopic immunocytochemistry of the cat retina confirmed the presence of guanylate cyclase in photoreceptor outer segments and demonstrated its association with disk and plasma membranes. These data support a concept in which guanylate cyclase is much more concentrated in the outer segments of cones than rods. The immunolabeling of the plexiform layers suggests that the particulate guanylate cyclase is not unique to the photoreceptor outer segments, and may also play a role in transduction processes of retinal synapses.
Nutrition practice guidelines define a systematic approach for medical nutrition therapy (MNT) provided by dietitians and are derived from scientific evidence and expert opinion. Nutrition practice guidelines for persons with non-insulin-dependent diabetes mellitus (NIDDM) can be implemented for those with newly diagnosed or previously diagnosed NIDDM at the first visit to a dietitian for initial or ongoing MNT. The guidelines apply to patients treated with MNT alone, MNT and oral glucose-lowering agents, or MNT and insulin. They provide a framework to assist the dietitian in the assessment, intervention (nutrition prescription, education, goal setting), and evaluation of outcomes for MNT. Minimum referral data for clinical decision making and outcome criteria are defined. Basic nutrition care is defined as one visit with the dietitian. Nutrition practice guidelines care consists of a series of visits with the dietitian. At the second follow-up visit, the dietitian assesses what has been accomplished with the nutrition interventions. If the patient has implemented the nutrition recommendations to the best of his or her ability and has not achieved the treatment goals, the dietitian should notify the physician and recommend that changes in medical management are needed. Ongoing nutrition care is recommended at 6-month to 1-year intervals for both basic and practice guidelines care.
OBJECTIVE: To assess the effect of medical nutrition therapy (MNT) provided by dietitians on medical and clinical outcomes for adults with non-insulin-dependent diabetes mellitus (NIDDM), and to compare MNT administered according to practice guidelines nutrition care (PGC) to MNT administered with basic nutrition care (BC). DESIGN: A prospective, randomized, controlled clinical trial of two levels of MNT on metabolic control in persons newly diagnosed with or currently under treatment for NIDDM was conducted at diabetes centers in three states (Minnesota, Florida, and Colorado). BC consisted of a single visit with a dietitian; PGC involved an initial visit with a dietitian followed by two visits during the first 6 weeks of the study period. Data were collected at entry to the study and at 3 and 6 months. SUBJECTS: Results are reported for 179 men and women aged 38 to 76 years: 85 assigned randomly to BC and 94 to PGC. This represents 72% of the 247 subjects enrolled. An additional 62 adults with NIDDM at one site who had no contact with a dietitian were identified as a nonrandom comparison group. OUTCOMES: Medical outcome measures included fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), and serum lipid levels. Clinical outcomes included weight, body mass index, waist-to-hip ratio, and changes in medical therapy. STATISTICAL ANALYSES: Initial analysis of the discrete variables was done using the chi 2 statistic with Yates' correction. Initial analysis of continuous variables was done by analysis of variance. The changes in variables between time periods were analyzed by paired t test, and comparisons between groups were analyzed using a t test for independent groups. RESULTS: At 6 months, PGC resulted in significant improvements in blood glucose control as indicated by FPG and HbA1c levels and BC resulted in significant improvements in HbA1c level. Participants assigned to the PGC group had a mean FPG level at 6 months that was 10.5% lower than the level at entry, and those in the BC group had a 5.3% lower value. Among subjects who had diabetes for longer than 6 months, those who received PGC had a significantly better HbA1c level at 3 months compared with those receiving BC. The comparison group showed no improvement in glycemic control over a comparable 6 months. PGC subjects had significant improvements in cholesterol values at 6 months, and subjects in both the PGC and the BC groups had significant weight loss. CONCLUSIONS: MNT provided by dietitians resulted in significant improvements in medical and clinical outcomes in both the BC and PGC groups and is beneficial to persons with NIDDM. Persons with a duration of diabetes longer than 6 months tended to do better with PGC than with BC. Because of the upward trend in glucose levels after 3 months, ongoing MNT by dietitians is important for long-term metabolic control.
Cutaneous infection with rapidly growing mycobacteria is uncommon and diagnosis may be difficult. However, the histopathological features are distinctive and may aid diagnosis. The three pathogenic species, Mycobacterium fortuitum, M. chelonae and M. abscessus, show major differences in their antimicrobial sensitivities, and species identification is therefore important. We describe a case of infection with M. abscessus, and discuss the clinical and pathological features of such infections, and approaches to their treatment.
A two-step procedure was used to place a cryIC crystal protein gene from Bacillus thuringiensis subsp. aizawai into the chromosomes of two B. thuringiensis subsp. kurstaki strains containing multiple crystal protein genes. The B. thuringiensis aizawai cryIC gene, which encodes an insecticidal protein highly specific to Spodoptera exigua (beet armyworm), has not been found in any B. thuringiensis subsp. kurstaki strains. The cryIC gene was cloned into an integration vector which contained a B. thuringiensis chromosomal fragment encoding a phosphatidylinositol-specific phospholipase C, allowing the B. thuringiensis subsp. aizawai cryIC to be targeted to the homologous region of the B. thuringiensis subsp. kurstaki chromosome. First, to minimize the possibility of homologous recombination between cryIC and the resident crystal protein genes, B. thuringiensis subsp. kurstaki HD73, which contained only one crystal gene, was chosen as a recipient and transformed by electroporation. Second, a generalized transducing bacteriophage, CP-51, was used to transfer the integrated cryIC gene from HD73 to two other B. thuringiensis subsp. kurstaki stains. The integrated cryIC gene was expressed at a significant level in all three host strains, and the expression of cryIC did not appear to reduce the expression of the endogenous crystal protein genes. Because of the newly acquired ability to produce the CryIC protein, the recombinant strains showed a higher level of activity against S. exigua than did the parent strains. This two-step procedure should therefore be generally useful for the introduction of an additional crystal protein gene into B. thuringiensis strains which have multiple crystal protein genes and which show a low level of transformation efficiency.
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Amyloid beta-peptide (A beta) has been shown to activate the classical complement pathway in vitro. Here, we demonstrate that this interaction is fully capable of killing cells and damaging cellular processes in mixed hippocampal cultures from embryonic day 18 rat fetuses. Lactic acid dehydrogenase (LDH) release and morphologic changes were used to evaluate toxicity.
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A 62-year-old man with chronic renal failure secondary to Wegener's granulomatosis received a cadaveric renal graft in December 1990 after 2 years' treatment with continuous ambulatory peritoneal dialysis. Early graft function was good and serum creatinine fell steadily. On day 5 he became anuric and the graft became swollen and tender. Isotope renography showed no perfusion and the kidney was removed. Pathological examination showed widespread acute arteritis consistent with recurrent Wegener's granulomatosis. Recurrence of Wegener's granulomatosis in renal grafts is rare. The 4 previously reported cases are reviewed.