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Biomedical subjects

D Rogers

Publications and source records attributed to D Rogers.

At least 37 records · Page 2Linked to original sources
PubMed1998

Efficacy of doxycycline and ciprofloxacin against experimental Yersinia pestis infection.

The efficacies of ciprofloxacin and doxycycline prophylaxis and therapy were assessed against experimental pneumonic plague infections induced by two strains of Yersinia pestis in a mouse model. When exposed to an aerosol of Y. pestis strain GB, containing 8.39 x 10(5) +/- 4.17 x 10(4) cfu, the retained dose was 7.3 x 10(3) +/- 2.3 x 10(3) cfu. When exposed to an aerosol of Y. pestis strain CO-92, containing 1.86 x 10(5) +/- 7.4 x 10(3) cfu, the retained dose was 3.4 x 10(4) +/- 2.6 x 10(3) cfu. Both strains resulted in a respiratory and systemic infection closely resembling human pneumonic plague. Ciprofloxacin prophylaxis and therapy was successful against both strains for up to 24 h after challenge, but not after 48 h. Both doxycycline prophylaxis and therapy regimens were ineffective against both strains, although strain CO-92 was more susceptible in vitro to doxycycline than strain GB and supra-MIC levels were achieved in the serum and lungs of the animal.

Animals↗
PubMed1998

Controlled trial of ketorolac in tension-type headache.

Intramuscular ketorolac 60 mg, meperidine 50 mg plus promethazine 25 mg, and normal saline were compared in acute exacerbations of tension-type headache. Forty-one subjects (30 females and 11 males) were randomized into three groups and evaluated by the McGill Short-Form Pain Questionnaire before treatment, and 0.5, 1, 2, 3, 4, 5, and 6 hours after treatment. All three groups showed a significant treatment effect that persisted for the 6 hours of evaluation. Ketorolac treatment was significantly better than placebo at 0.5 and 1 hour by the Visual Analog Scale (VAS) and Pain Rating Index, and better than meperidine at 2 hours (by the VAS). Meperidine and placebo did not differ at any time point. Ketorolac is effective in short-term treatment of tension-type headache.

Adolescent↗
PubMed1998

Attitudes to the use of health outcome questionnaires in the routine care of patients with diabetes: a survey of general practitioners and practice nurses.

BACKGROUND: Despite the increasing availability of multidimensional health status and outcome measures of the patient's physical and emotional functioning, and a number of national initiatives to promote their use, little is known about the attitudes and behaviour of general practitioners (GPs) and practice nurses (PNs) regarding their use in evaluating the effectiveness of health care. What evidence there is remains largely anecdotal but supports the view that health outcome data is currently not used in the routine management of the patient. AIM: To investigate the attitudes and behaviour of GPs and PNs regarding the use of health outcome data in the routine care of patients with diabetes. METHOD: A questionnaire comprising 20 attitudinal and behavioural statements covering the use and benefits of health outcome data in the routine care of patients with diabetes were sent to 156 GPs and 114 PNs in the Doncaster area together with a covering letter and two examples of multidimensional health outcome measures. RESULTS: Completed questionnaires were received from 90 (58%) GPs and 49 (50% corrected for out of scope) nurses. Median response scores showed that both GPs and nurses expressed a positive overall attitude towards health outcome measurement giving responses favourable to it in 15 (75%) and 18 (90%) of the statements respectively. A key finding was that 48% and 46% of GPs and PNs were unclear as to how they would use health outcome data. CONCLUSION: While our findings reflect a favourable view towards the use of health outcome data for the routine management of the patient with diabetes in a general practice setting, a number of important barriers to their implementation have been identified. These include insufficient knowledge on their use, the need for easily interpretable data, and a lack of resources.

Adult↗
PubMed1997

Spatial regulation of neuronal gene expression in response to nerve growth factor.

To examine the cellular mechanisms whereby distally derived growth factors regulate nuclear responses in neurons, we have utilized compartmented cultures of sympathetic neurons to examine the regulation of two nerve growth factor (NGF)-inducible genes, tyrosine hydroxylase (TH) and p75 neurotrophin receptor (p75NTR). These studies demonstrate that NGF can signal retrogradely to mediate the induction of TH and p75NTR mRNAs. However, quantitative differences occurred as a function of the spatial localization of NGF exposure; application of NGF to cell bodies and proximal axons elicited peak levels of neuronal gene expression that were two- to threefold higher than when NGF was applied to distal axons alone. Furthermore, neurons responding maximally to NGF on distal axons were still able to respond to NGF administered to cell bodies and proximal axons. Biochemical analysis indicated that this difference in responsiveness was not due to differences in the number of TrkA/NGF receptors in the two compartments. Thus, although NGF signals retrogradely to mediate nuclear responses, the magnitude of these responses differs as a function of the spatial location of the activated NGF receptor:ligand complex. Moreover, these data suggest that neurons may be able to respond to a second cellular source of neurotrophins, even when target-derived neurotrophins are not limiting.

Animals↗
PubMed1997

Univariate analysis of tsetse habitat in the common fly belt of southern Africa using climate and remotely sensed vegetation data.

Tsetse are vectors of trypanosomes that cause diseases both in humans and livestock. Traditional tsetse surveys, using sampling methods such as Epsilon traps and black screen fly rounds, are often logistically difficult, costly and time-consuming. The distribution of tsetse, as revealed by such survey methods, is strongly influenced by environmental conditions, such as climate and vegetation cover, which may be readily mapped using satellite data. These data may be used to make predictions of the probable distribution of tsetse in unsurveyed areas by determining the environmental characteristics of areas of tsetse presence and absence in surveyed areas. The same methods may also be used to characterize differences between tsetse species and subspecies. In this paper we analyse the distribution of Glossina morsitans centralis, Glossina morsitans morsitans and Glossina pallidipes in southern Africa with respect to single environmental variables. For G.m.centralis the best predictions were made using the average NDVI (75% correct predictions; range > 0.37) and the average of the maximum temperature (70% correct predictions; 27.0-29.2 degrees C). For G.m.morsitans the best prediction was given by the maximum of the minimum temperature (84% correct predictions; range > 18.8 degrees C), and for G.pallidipes, also by the maximum of the minimum temperature (86% correct predictions; range > 19.6 degrees C). The following paper compares a range of multivariate techniques for making predictions about the distribution of these species in the same region.

Africa, Southern↗
PubMed1997

Mapping tsetse habitat suitability in the common fly belt of southern Africa using multivariate analysis of climate and remotely sensed vegetation data.

The distribution of Glossina morsitans centralis, Glossina morsitans morsitans and Glossina pallidipes are described in part of southern Africa, using a range of multivariate techniques applied to climate and remotely sensed vegetation data. Linear discriminant analysis is limited in its predictive power by the assumption of common covariances in the classes within multivariate environment space. Maximum likelihood classification is one of a variety of alternative methods that do not have this constraint, and produce a better prediction, particularly when a priori probabilities of presence and absence are taken into account. The best predictions are obtained when the habitat is subdivided, prior to classification, on the basis of a bimodality detected on the third component axis of a principal component analysis. The results of the predictions were good, particularly for G.m.centralis and G.m.morsitans, which gave overall correct predictions of 92.8% and 85.1%, with a Kappa index of agreement between the prediction and the training data of 0.7305 and 0.641 respectively. For G.pallidipes, 91.7% of predictions were correct but the value of Kappa was only 0.549. Very clear differences are demonstrated between the habitats of the two subspecies G.m.centralis and G.m.morsitans.

Africa, Southern↗
PubMed1997

MYCN oncogene amplification in neuroblastoma is associated with worse prognosis, except in stage 4s: the Italian experience with 295 children.

PURPOSE: To evaluate the prognostic role of MYCN oncogene amplification in children with neuroblastoma. PATIENTS AND METHODS: Of 694 children (age, 0 to 15 years) with previously untreated neuroblastoma, 295 (42%) were evaluated at diagnosis for MYCN gene amplification. RESULTS: Clinical characteristics and survival results of 295 patients studied and 399 not studied for MYCN were comparable. In 48 of 295 patients studied for MYCN (16%), the gene was amplified (> or = three gene copies). Amplification was more frequent in children older than 1 year, with abdominal tumor (18% v 7%), advanced disease, normal vanillylmandelic (VMA) urinary excretion, and high lactate dehydrogenase (LDH), ferritin, and neuron-specific enolase (NSE) serum levels. In patients studied for MYCN, the 5-year overall survival (OS) rate was higher for children aged less than 1 year (90% v 44%), with extraabdominal tumor, stage 1 or 2 versus 3 versus 4, and normal NSE, LDH, and ferritin serum levels. Patients with amplified MYCN had a worse OS (odds ratio [OR], 3.38; confidence interval [CI], 2.22 to 5.16). This association held after adjustment for other characteristics. The impact of MYCN amplification was greater in patients with favorable characteristics, in particular age (OR, 10.28 for infants; 2.08 for older children) and stage (OR, 35.3 for stage 1 to 2; 8.41 for stage 3; 1.76 for stage 4). However, of 29 children with stage 4s, all three with amplified MYCN survive. In a multivariate analysis, the prognostic role of MYCN amplification, age, and stage was confirmed, but the size of the effect of MYCN was dependent on age and stage. CONCLUSION: MYCN amplification is associated with a worse prognosis in children with neuroblastoma at all ages and stages except 4s. This association is most pronounced in children with otherwise favorable prognostic indicators, and in these children should be considered as an indication for more intensive intervention.

Adolescent↗
PubMed1996

Social Corroboration and Opinion Extremity

Four studies found that social corroboration of one's (pro/con) attitudinal position leads to increases in attitude extremity. Study 1 focused on attraction ratings made by college women. This study demonstrated both increases in opinion extremity following corroboration and decreases in opinion extremity following contradiction. Study 2 focused on dental chair comfort ratings made by dental patients and found greater opinion extremity following corroboration from either fellow patients or the dentist. Study 3 reported greater charity donation amounts as well as heightened opinion confidence following corroboration. Study 4 replicated Study 1 varying duration of stimulus exposure and found that, as predicted, confidence scores were affected more by the corroboration/contradiction manipulation when initial exposures were brief. Unexpectedly, however, the affect of corroboration on attraction ratings, was not moderated by initial exposure time. Rather, across both long and short exposure times, attraction scores were most extreme following corroboration and least extreme following contradiction. Path analyses in Study 4 supported the view that this association between corroboration and extremity was mediated by confidence. This research indicates that the relationship between corroboration and opinion extremity appears to be respectably robust across populations and target variables, and is not specific to sensitive within subject designs. Moreover, Study 3 indicates that social corroboration is capable of increasing the extremity of behavior having real consequences for participants. The data are discussed in terms of possible moderator variables, as well as theories of group polarization and opinion extremity.

Journal Article↗
PubMed1996

Mutational spectrum in the neurofibromatosis type 2 gene in sporadic and familial schwannomas.

Using a heteroduplex approach and direct sequencing, we have completed the screening of approximately 88% of the neurofibromatosis type 2 (NF2)-coding sequence of DNA extracted from 33 schwannomas from NF2 patients and from 29 patients with sporadic schwannomas. The extensive screening has resulted in the identification of 33 unique mutations. Similarly to other human genes, we have shown that the CpG sites are more highly mutable in the NF2 gene. The frequency, distribution, and types of mutations were shown to differ between the sporadic and familial tumors. The majority of the mutations resulted in protein truncation and were consistent with more severe phenotype, however three missense mutations were identified during this study and were all associated with milder manifestations of the disease.

Codon↗
PubMed1996

Postprandial insulin profiles with implantable pump therapy may explain decreased frequency of severe hypoglycemia, compared with intensive subcutaneous regimens, in insulin-dependent diabetes mellitus patients.

PURPOSE: To examine the mechanism of the decreased frequency of severe hypoglycemia with implantable pump therapy compared with subcutaneous intensive therapy. PATIENTS AND METHODS: Eight subjects with insulin-dependent diabetes mellitus (IDDM), enrolled in an implantable insulin pump study, were admitted to the General Clinical Research Center and on 2 separate days were given either a dose of preprandial insulin chosen to maintain normoglycemia for a standard (450 kcal, 50% carbohydrate) breakfast or 1.75 times the dose. The two doses were administered subcutaneously (by syringe or with an external pump) during one inpatient admission and by implantable pump (intraperitoneally, n=6; or intravenously, n=2) during a separate admission. Blood glucose, plasma-free insulin, and neurocognitive function were measured for 4 hours after the meal. RESULTS: Subcutaneous administration resulted in 7 episodes of hypoglycemia (2 with the usual dose and 5 with the 1.75-fold dose), defined as blood glucose less than 50 mg/dL; implantable pump treatment resulted in only 2 episodes, both with the 1.75-fold dose (P <0.05, Fisher's two-tailed test for implantable versus subcutaneous). Compared with subcutaneous delivery, implantable pump therapy provided significantly lower insulin levels during the final 2 hours after administration of the usual dose and the 1.75-fold dose (P <0.005). In addition to the decreased frequency of hypoglycemia, implantable pump therapy resulted in significantly lower area under the glycemia curve during the first 120 minutes with the 1.75-fold dose compared with subcutaneous administration. CONCLUSIONS: The lower frequency of severe hypoglycemia with intensive therapy administered by implantable pump therapy is explained by the more rapid clearance of insulin delivered intraperitoneally or intravenously compared with intensive subcutaneous injection regimens. The lower frequency of severe hypoglycemia with implantable pump therapy compared with subcutaneous therapy demonstrated in clinical trials is confirmed by this study, in which we attempted to induce hypoglycemia.

Adult↗
PubMed1996

The descriptive epidemiology of tinea pedis in the community.

Tinea pedis is a common inflammatory skin condition due to infection by dermatophyte fungi. A number of epidemiological studies have been completed on the frequency of tinea pedis in the community, particularly sporting and occupational groups and schools. Most studies have focused on small, high-risk populations. These include occupational groups involving manual labour, sporting groups such as swimmers, and those working or living in confined conditions with shared washing facilities, which favour the opportunity for cross-infection. Most studies show that the frequency of tinea pedis is higher in males than females. Tinea pedis infections appear to be least common among children, but do occur, and are commonly misdiagnosed. The difference between clinical disease and confirmed diagnosis by culture is not always clear when statistics of disease frequency have been presented. Clear diagnosis criteria indicating the level of mycologically confirmed diagnosis should be reported in future studies that include statistics on disease frequency. Future epidemiological studies should also aim to be population-based in order to obtain a more complete picture of disease frequency.

Adolescent↗
PubMed1996

Effects of heredity, age, weight, puberty, activity, and calcium intake on bone mineral density in children.

Osteoporosis is a disease that plagues older individuals, particularly women. At the usual age of diagnosis, limited therapy is available. By further delineating the factors that influence bone mineral acquisition before peak bone density is achieved, individuals at risk may be identified at an earlier age when therapies may be more effective. This was a study of 16 family units, 16 mothers, eight fathers, and their 28 children between the ages of 5 and 20 years. The evaluation consisted of a focused history, Tanner staging of adolescents, anthropometric data (height, weight), and spinal bone mineral density (BMD) by DEXA (dual-energy x-ray absorptiometry). Bone mineral density in the children was compared with multiple environmental factors. Bone mineral density Z-scores were then compared between children and their parents. Variables found to be positively correlated with children's BMDs were: age (r = 0.94, P < 0.001), Tanner stage (r = 0.90, P < 0.001), weight (r = 0.88, P < 0.001), height (r = 0.81, P < 0.001), and body mass index (r = 0.77, P < 0.001). No association was found between calcium intake and BMD, owing possibly to increased calcium intake among children with a family history of osteoporosis. Activity was not significantly associated with BMD. Significant correlations were noted between the children's BMD and that of their father's (r = 0.83, P = 0.01), premenopausal mother's (r = 0.58, P = 0.03), and midparental (the mean value of both parents' BMDs) (r = 0.86, P = 0.01). These data suggest that children who have parents affected by low BMD may be at risk for low BMD themselves.

Absorptiometry, Photon↗
PubMed1996

Physical aspects of alleged sexual assaults.

The medical evidence, detailing the physical findings, is just one component in the investigation of serious sexual assault and it is not for the doctor alone to determine the veracity of an allegation. This paper has described some of the factors which limit the quality and value of the medical evidence. Potential ways to rectify the problems are: 1. A requirement that all doctors who examine complainants of sexual assault should have undergone basic theoretical and practical training and be required to continue their education by attendance at update meetings and participating in peer review groups. 2. Large-scale, well-designed research projects which relate the physical findings to the outcome of the case. 3. Routine colposcopic assessments with photo-documentation of the genital examinations of all complainants of serious sexual offences. 4. Pretrial debate amongst medical experts.

Adult↗