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Biomedical subjects

J Rodgers

Publications and source records attributed to J Rodgers.

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

A chemical gas incident in London: how well prepared are London A & E departments to deal effectively with such an event?

This study aimed to investigate the preparedness of inner London Accident and Emergency (A & E) departments in the event of a major chemical incident. The dimensions of preparedness studied were procedures, facilities and equipment, protective clothing, knowledge, and attitudes towards chemical incidents. A review of the relevant literature will be published in issue 6/3 of this journal, July 1998.

Attitude of Health Personnel↗
PubMed1997

Interaction of the cytoplasmic tail of CTLA-4 (CD152) with a clathrin-associated protein is negatively regulated by tyrosine phosphorylation.

CTLA-4 (CD152), high-avidity receptor for CD80 and CD86, is a powerful regulator of T cell activation. While CTLA-4 functions at the cell surface, it is primarily localized in intracellular vesicles and cycles to the cell surface. The CTLA-4 cytoplasmic domain contains sequences that direct its intracellular localization and regulate its signaling. Here we demonstrate that effector molecules involved in receptor trafficking and signaling interact with distinct, but overlapping, sequences in the CTLA-4 cytoplasmic domain. Using the yeast two-hybrid method, we demonstrate association of the mu2 subunit of AP-2, the clathrin-associated complex found in plasma membrane-associated coated pits, with the cytoplasmic tail of CTLA-4, but not CD28. The mu1 subunit of AP-1, found in Golgi-associated coated pits, associated with neither CTLA-4 nor CD28. Sequences required for interaction of mu2 and CTLA-4 were localized to residues, 161TTGVY in CTLA-4; this sequence is N-terminal to, but overlaps with, a previously identified SH2 binding motif, 165YVKM, involved in CTLA-4 signaling. Mu2 interacted preferentially with CTLA-4 when residue 165Y was nonphosphorylated, whereas a PI3 kinase SH2 domain interacted preferentially when 165Y was phosphorylated. In co-transfection experiments, both tyrosine residues in the cytoplasmic tail of CTLA-4 (165Y and 182Y) were phosphorylated by the T lymphocyte-associated tyrosine kinase, p56lck. Thus, phosphorylation of CTLA-4 residue 165Y may reciprocally regulate signaling and trafficking of CTLA-4 by determining which effector molecules bind to its cytoplasmic tail.

Abatacept↗
PubMed1997

Deleted in colorectal carcinoma (DCC) binds heparin via its fifth fibronectin type III domain.

DCC (deleted in colorectal carcinoma) is a broadly expressed cell-surface receptor. Netrin-1 was recently identified as a DCC ligand in brain, but the possibility of other DCC ligands was suggested by the finding that an anti-DCC antibody (clone AF5) neutralized netrin-1-dependent commissural axon outgrowth without blocking DCC/netrin-1 interactions. Here we have searched for alternative cell-surface DCC ligands. A DCC-Ig fusion protein bound to neural and epithelial derived cell lines, indicating that these lines express ligand(s) for DCC. The cell-surface binding activity was mediated by the loop between beta-strands F and G of the fifth fibronectin type III repeat FNIII-D5. The loop included the sequence KNRR, which resembles heparin-binding motifs in other proteins. Heparinase and heparitinase treatment of cells reduced binding of DCC-Ig, suggesting that heparan sulfate proteoglycans are cell-surface DCC ligand(s). This was further supported by heparin blocking experiments and by binding of DCC-Ig to immobilized heparan sulfate. The interaction between DCC-Ig and heparan sulfate/heparin, both on the surface of cells and immobilized on plastic, was blocked by the same anti-DCC antibody that blocks netrin-1-dependent commissural axon outgrowth. Taken together, these findings suggest that the DCC-Ig/heparin interaction may contribute to the biological activity of DCC.

Amino Acid Sequence↗
PubMed1997

A substance P antagonist, RP-67,580, ameliorates a mouse meningoencephalitic response to Trypanosoma brucei brucei.

Mice infected with the protozoan parasite Trypanosoma brucei brucei and treated subcuratively with the trypanocidal drug diminazene aceturate develop an acute inflammatory meningoencephalitis with associated astrocytic proliferation. This reaction is very similar to that seen in the fatal posttreatment reactive encephalopathies that can occur in human African trypanosomiasis. The 11-amino acid neuropeptide substance P (SP) has recently been identified as a mediator in many inflammatory responses, and the development of potent, highly specific, nonpeptide SP antagonists has provided a new opportunity to investigate the possible involvement of SP in a variety of pathological conditions. We therefore postulated that SP may play a role in the development of the posttreatment inflammatory encephalopathy found in this experimental mouse model of African trypanosomiasis. In the present study RP-67,580, a SP antagonist that binds specifically to NK-1 receptors, was given intraperitoneally at a dose of 2 mg/kg twice daily to mice in which a severe meningoencephalitis had been produced. A significant reduction in both the severity of the inflammatory response (P = 0.0001) as well as the degree of astrocyte activation (P < 0.001) was found in the brains of these animals as compared with control mice that had not received RP-67,580. An inactive enantiomer of this SP antagonist, RP-68,651, had no effect on the central nervous system inflammatory reaction. We conclude from these findings that the neuropeptide SP plays a key role in the development of the severe central nervous system inflammatory response associated with African trypanosomiasis.

Analgesics↗
PubMed1997

Atomic force microscope imaging of DNA and DNA repair proteins: applications in radiobiological research.

By using the atomic force microscope (AFM), three-dimensional structures of biological specimens may be imaged at nanometer resolution. Furthermore, samples can be imaged in air or in fluid environments. The tapping mode of AFM operation for imaging has offered a significant advance in visualizing soft biological structures, such as DNA, proteins, and membranes. Here, we review the principles underlying the application of this instrument to radiation biological investigations. We focus on examples of proteins involved in the processes of repair of damaged DNA, including poly(ADP-ribose) polymerase, Ku protein, and DNA protein kinase. Novel observations on the character of DNA damage and repair have been addressed by direct visualization of DNA and protein-DNA interactions, such as the observation that the Ku protein is capable of physically joining DNA fragments in vitro. The AFM offers a powerful tool for investigating biologically important molecular interactions that are relevant to DNA damage and repair processes.

Air↗
PubMed1997

Anti-malarial drug resistance, malnutrition and socio-economic status.

To investigate the relationship between nutritional status and resistance to chloroquine treatment, we designed a nested case-control study prospective with respective to the outcome of Plasmodium falciparum-infected school children aged 5-14 years from Honiara, Solomon Islands. 38 chloroquine-resistant cases were compared with treatment-susceptible controls with respect to current nutritional status, behavioural characteristics, medical and demographic data. The overall prevalence of moderate malnutrition was 28%. The incidence rate of chloroquine resistance was 23%. Malnourished children were generally at higher risk for treatment failure than well-nourished ones (OR: 3.6; 95% CI: 1.6-8.4; P = 0.001). This effect was modified by socio-economic status. Stratified analysis by logistic regression resulted in an eightfold risk of resistance for malnourished children in the higher socio-economic category (OR: 8.1; 95% CI: 2.4-27.9; P = -.0001). In children from the lower socio-economic group, the effect of malnutrition was not significant (OR: 1.5; 95% CI: 0.4-5.6). Socio-economic differences may affect the immune status. The treatment response in children of lower socio-economic status, which are more exposed to malaria, may therefore be less affected by malnutrition.

Adolescent↗
PubMed1997

Derivation and validation of a pulmonary tuberculosis prediction model.

OBJECTIVE: To describe the derivation and validation of a pulmonary tuberculosis (TB) prediction model that would enable early discontinuation of unnecessary respiratory isolation. DESIGN: Patients placed in isolation for suspected pulmonary TB were studied retrospectively (derivation cohort) and prospectively (validation cohort). Independent predictors of pulmonary TB in the derivation cohort (January 1992-March 1994) were identified by retrospective analysis. Predictors in the model were assigned weights on the basis of the results of the multivariate analysis in order to quantitate the risk of TB in an individual patient. The prospective validation consisted of application of the model to patients placed in isolation during the period April 1994 to June 1995. The predictability of the model in the derivation and validation cohorts was evaluated using receiver operating characteristics (ROC), curve analysis, and calculation of the area under the ROC curve (AUC). SETTING: A university-affiliated, urban, public hospital with a large population of prison inmates and patients with human immunodeficiency virus infection. INTERVENTIONS: Prospective application of the prediction model to patients placed in isolation during the validation period. RESULTS: Four factors were found to be independent predictors of pulmonary TB among 296 isolation episodes in the derivation cohort; positive acid-fast sputum smear (odds ratio [OR], 5.8; 95% confidence interval [CI95], 3.0-11.0; weight = 3 points), localized chest radiograph findings (OR, 2.5; CI95, 1.3-4.9; weight = 2 points), residence in a correctional facility (OR, 2.3; CI95, 1.2-4.4; weight = 2 points), and history of weight loss (OR, 1.8; CI95, 1.0-3.2; weight = 1 points). Infection control practitioners applied the model prospectively to 220 isolation episodes. The mean (+/-SE) AUCs of the ROC curve for the derivation and validation cohorts were not significantly different (.86 +/- .04 vs .86 +/- .07; P = .90). There was a significant decline in the mean duration of isolation from the onset of an automatic TB isolation policy in August 1992 to the end of the study (P = .045 by analysis of variance). CONCLUSIONS: A pulmonary TB prediction model was derived and validated prospectively in a hospital with a moderately high prevalence of TB. The model quantitated the risk of TB in an individual patient and aided infection control practitioners and primary-care physicians in their decisions to discontinue isolation during the validation period. Utilization of the model was responsible, in part, for a decrease in the mean duration of isolation during the study period. Although the model may not have general applicability due to the uniqueness of the patient population studied, this study illustrates how prediction models can be developed and used effectively to deal with a clinical problem.

Adult↗
PubMed1997

The role of the polyamine inhibitor eflornithine in the neuropathogenesis of experimental murine African trypanosomiasis.

The treatment of late-stage human African trypanosomiasis is complicated by a post-treatment reactive encephalopathy, also referred to as a 'reactive arsenical encephalopathy', that may be fatal. This study used a well established experimental mouse system to assess the use of the trypanostatic drug, eflornithine, in the management of this post-treatment reaction. Female CD-1 mice infected with an eflornithine-resistant trypanosome stabilate and treated with the trypanocidal compound diminazene aceturate on or after day 21 post-infection develop a reactive encephalopathy and relapsing parasitaemia. If these animals are re-treated with diminazene aceturate, a severe encephalopathy develops histologically comparable with that of human cases and characterized by a severe meningoencephalitis and astrogliosis. Histopathological and immunocytochemical examination shows that administration of eflornithine before or after the development of this reactive encephalopathy prevented or ameliorated the inflammatory reaction. Since an eflornithine resistant stabilate was used, this effect appears to be independent of the drug's trypanostatic action and illustrates an important, previously unrecognized, pharmacological property of eflornithine. Consideration can now be given to the use of eflornithine for the management of human trypanosomiasis cases, even where trypanosome resistance to eflornithine exists.

Animals↗
PubMed1997

Publishing workshops number 4. Preparing a manuscript: reviewing literature.

In this paper we have looked at the different avenues for nurses to contribute to the knowledge base of the discipline by writing about nursing literature. We emphasised the responsibility that goes with this action. As with all writing the starting point is for the author to define the boundaries of the work, and then decide what it is that she or he wants to communicate. After that it is a matter of planning a logical and coherent sequence and proceeding to develop the content in language that is as simple and effective as possible. Reference was made to the general guidelines for writing proposed in an earlier workshop (Chick et al, 1996). In this paper three different forms, a review article, a literature review and review of a piece of literature have been discussed, noting the purposes that each serves and the way in which, to a large extent, purpose dictates both content and the order and priority to be given to the various sections. Three of the key dimensions along which variation can occur are scope, critical emphasis, and relevance to practice.

Humans↗
PubMed1996

Expression of nerve growth factor and epidermal growth factor receptors in neural nevi with nevic corpuscles.

The histogenesis of "nevic corpuscles" (NCs) in neural nevi is still controversial. Recent studies have revealed that nerve growth factors (NGFs) and other growth factors [that is, epidermal growth factor (EGF)] could have various paracrine and autocrine functions on Schwann cells and melanocytes. We examined the immunohistochemical expression of NGF and EGF receptors (r) in 15 cases of neural nevi containing NCs along with 37 cases of other benign and malignant melanocytic lesions without neural differentiation (total, 52). Section were prepared from formalin-fixed and paraffin-embedded tissues. Monoclonal antibodies to NGFr and EGFr were used with the Avidin-biotin-complex (ABC) technique. We found strong reactivity for NGFr in 14 of 15 neural nevi with a predilection for NCs, but only eight of 37 were positive in the other group of melanocytic lesions without neural differentiation (four Spitz nevi, two melanomas, and two compound nevi). EGFr expression was limited mainly to NCs in four cases of neural nevi. We conclude that neural differentiation and NC formation are associated with NGFr overexpression, whereas EGFr expression is only limited. The relative paucity of NGFr expression in other type of benign and malignant melanocytic lesions supports the view that neural "differentiation" is a distinct process in certain long-standing melanocytic nevi. We postulate that NGFr overexpression may be the result of the reactivation of oncofetal genes that could become manifest in either abnormal schwannian differentiation (as seen in neural nevi), in a neoplastic context (as seen in neural and melanocytic tumors).

Adult↗
PubMed1996

Psychiatric manifestations of multiple sclerosis: a review.

OBJECTIVE: To report the occurrence, type, causes, and management of psychiatric manifestations in multiple sclerosis (MS). METHOD: Review of recent, relevant literature. RESULTS: Psychiatric illness, especially depression, occurs much more frequently than expected in patients with MS, is frequently unrecognized or ignored, and is treatable using standard methods, although patients with MS may be unusually sensitive to side effects of tricyclic antidepressants. CONCLUSIONS: Research is needed to better define the causes of psychiatric syndromes in patients with MS. Those treating MS should increase their awareness of and sensitivity to the likelihood of psychiatric disorder in these patients.

Adaptation, Psychological↗
PubMed1996

Changes in practice in the use of subcutaneous diamorphine via syringe driver.

A study was undertaken in 1988 to examine various aspects of administering diamorphine subcutaneously by syringe driver at the time when its use had recently been introduced into the community. The results of this study and of a comparative study undertaken in 1994 are reported. It was found that in both studies the syringe driver was used mainly for patients who were unable to take oral medication or who were vomiting. However, in the first study, subcutaneous diamorphine was used in 31% of patients with no absorption problems, to improve pain control in those whose pain was poorly controlled on oral medication. In the second study, the syringe driver was used in only 8% of patients for this purpose. In both studies the use of the driver was continued until death in 37 of the 39 patients (95%) in each group. The syringe driver was used for longer than 14 days in most patients (56%) in the first study and the dose of diamorphine was increased in 54% of patients. In the second study, the driver was used mainly in the last week of life (69%) and the dose was more stable, remaining unchanged in 69% of patients. The incidence of site complications (5%) was the same in both groups, but other problems occurred with the use of the driver in the first group.

Adult↗
PubMed1996

Potential for professional profit: the making of the New Zealand Army Nursing Service 1914-1915.

This article examines the development of the New Zealand Army Nursing Service between August 1994 and April 1995. War was seen as an opportunity to further promote the new order of nursing, and nurses fought against the employment of amateur war-time workers to help with nursing duties. However, despite the central place trained nurses held in civilian nursing by 1914, they faced gender-based barriers in order to achieve a place within military structures during World War I.

Female↗
PubMed1996

Cost of administering controlled drugs in a hospice ward.

A study was undertaken in 1995 to examine the time taken to administer Controlled Drugs (CDs) in one of the two seven-bedded wards in the Prince and Princess of Wales Hospice (PPWH) in the course of one week. A stop watch was used to measure the time taken from the decision to give a CD until its administration was entered into the CD Register. The drugs used were oral morphine, oral sustained release morphine and diamorphine for subcutaneous administration by syringe driver. The grade of nurses involved in administering the CDs was also recorded. The time taken by D, E, F, and G grade nurses was extrapolated to the number of hours per annum spent administering the CDs. The hourly rate for the various grades was documented and the total cost calculated. The total annual cost of administering CDs to the seven patients in the study was calculated to be 10,883.94 pounds. The total cost for the two wards was extrapolated to 21,767.88 pounds. The annual cost of the CDs was 7,294.63 pounds. The total cost of the CDs and their administration was 29,062.51 pounds: 75% of the expenditure is the cost of administration. Syringe drivers cost twice as much to administer as sustained release morphine tablets.

Analgesics, Opioid↗