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Biomedical subjects

R Bell

Publications and source records attributed to R Bell.

At least 91 records · Page 5Linked to original sources
PubMed1998

Antenatal and perinatal antecedents of moderate and severe spastic cerebral palsy.

Routinely collected perinatal morbidity data were abstracted for 204 cases of moderate and severe spastic cerebral palsy and 816 matched controls. Separate analyses were conducted for cases with birth-weight > or = 2,500 g and birth-weight < 2,500 g. The presence of a congenital abnormality was an important risk factor for cerebral palsy in both groups and further analyses were conducted after dividing the groups according to presence or absence of a congenital abnormality. In the < 2,500 g group, resuscitation needed was clearly identified as a risk factor for cerebral palsy in the group with no congenital abnormalities (adjusted OR=3.4; 95% CI=1.6-7.5) while in the group with congenital abnormalities, none of the risk factors were clearly associated with an increased risk of cerebral palsy. Among the cases with birth-weight > or = 2,500 g, intrauterine hypoxia/birth asphyxia was clearly associated with an increased risk of cerebral palsy (adjusted OR=18.1; 95% CI=1.8-186) in the group with no congenital abnormalities while in the group with congenital abnormalities, none of the factors were clearly associated with an increased risk of cerebral palsy.

Asphyxia Neonatorum↗
PubMed1998

Cervicovaginal fetal fibronectin testing in threatened preterm labour--translating research findings into clinical practice.

A retrospective audit was undertaken involving 70 women with a singleton pregnancy who attended hospital with symptoms of threatened preterm labour prior to 34 weeks' gestation and who had a bedside fetal fibronectin (FFN) Membrane Immunoassay Kit Test (Adeza Biomedical) performed. The aim of the study was to determine if the results of the FFN test when used in routine clinical practice would be similar to those of a previous research study (1) that was performed at the same centre, and whether or not knowledge of the result of the FFN test might influence clinical management. The audit revealed that the sensitivity of the FFN test in the prediction of delivery prior to 34 weeks' gestation was 90%, the specificity was 82%, whilst the positive and negative predictive values were 45% and 98% respectively. These results were very similar to those of the previous, blinded research study. Compared to women with a negative FFN test, more women with a positive FFN test received corticosteroids (100% versus 71%, p=0.02) and tocolysis (35% versus 12%, p=0.04) and more remained in hospital longer than 24 hours (85% versus 56%, p=0.1).

Body Fluids↗
PubMed1998

Enhancement of latent inhibition in the rat at a high dose of clozapine.

The present experiments investigated clozapine (2.5, 5 and 10 mg/kg) and haloperidol (0.1 mg/kg) administration on latent inhibition (LI) in rats. Clozapine's ability to antagonize amphetamine-induced disruption of LI was also assessed. A conditioned emotional response procedure was employed. In the pre-exposure stage, 'pre-exposed' rats received 10 (Experiment 1) or 40 (Experiment 2) presentations of a flashing light stimulus without reinforcement. During the conditioning phase, the light stimulus was paired with a footshock. At test, LI was expressed by the extent of suppression of water licking during flashing light presentation. Both clozapine (10 mg/kg) and haloperidol (0.1 mg/kg) significantly facilitated LI. In addition, clozapine significantly reversed the disruption of LI induced by amphetamine (1.0 mg/kg). These results with clozapine illustrate that LI is sensitive to antipsychotics which differ in their mode of action and furthermore emphasize the value of LI as a test model for detecting the antipsychotic potential of novel drugs.

Animals↗
PubMed1998

The effect of low-dose heparin on hypercoagulability following abdominal aortic surgery.

The effect of low-dose heparin on postoperative hypercoagulability was assessed using thrombelastography (TEG) in eighteen patients undergoing elective abdominal aortic surgery. Patients received unfractionated heparin 5000IU bd SC commencing on the first postoperative day. Native whole blood TEG was performed preoperatively and on day two postoperatively. A heparinase-modified TEG was performed at the same time as the native whole blood TEG on day two. There were no significant changes in the postoperative native whole blood TEG variables (r, K, alpha, MA) relative to preoperative controls. In contrast, there were significant decreases in r and K, and increases in alpha in the heparinase-modified TEGs postoperatively (P < 0.01). There were significant differences between the postoperative native whole blood and heparinase-modified TEGs for all TEG variables (P < 0.01). The results indicate that low-dose heparin reduces postoperative hypercoagulability following abdominal aortic surgery as assessed by thrombelastography.

Aged↗
PubMed1998

Long-term pamidronate treatment of advanced multiple myeloma patients reduces skeletal events. Myeloma Aredia Study Group.

PURPOSE: To determine the efficacy and safety of 21 monthly cycles of pamidronate therapy in patients with advanced multiple myeloma. PATIENTS AND METHODS: Patients with stage III myeloma and at least one lytic lesion received either placebo or pamidronate 90 mg intravenously administered as a 4-hour infusion monthly for 21 cycles. At study entry, the patients were stratified according to whether they were to receive first-line (stratum 1) or second-line (stratum 2) antimyeloma chemotherapy. Skeletal events (pathologic fracture, radiation or surgery to bone, and spinal cord compression) and hypercalcemia were assessed monthly. RESULTS: The results of the first nine previously reported cycles are extended to 21 cycles. Of the 392 randomized patients, efficacy could be evaluated in 198 who received pamidronate and 179 who received placebo. After 21 cycles, the proportion of patients who developed any skeletal event was lower in the pamidronate-group (P = .015). The mean number of skeletal events per year was less in the pamidronate-group (1.3) than in placebo-treated patients (2.2; P = .008). Although survival was not different between the pamidronate-treated group and placebo patients overall, stratum 2 patients who received pamidronate lived longer than those who received placebo (14 v 21 months, P = .041). Pamidronate was safe and well tolerated during the 21 cycles of therapy. CONCLUSION: Long-term monthly infusions of pamidronate as an adjunct to chemotherapy are superior to chemotherapy alone in reducing skeletal events in stage III multiple myeloma patients, and may improve the survival of patients on salvage therapy.

Diphosphonates↗
PubMed1998

The clinical use of plasma clozapine levels.

OBJECTIVE: This review examines the evidence supporting the proposition that a threshold clozapine plasma level can predict clinical response. In addition, it provides a brief overview of the pharmacokinetics, side effects, drug interactions and assay methodology of clozapine. METHOD: A comprehensive search of relevant literature was made with respect to the above criteria. The findings were collated and analysed to produce an overview of the usefulness of using clozapine levels in clinical practice. RESULTS: Most researchers find that, although the correlation between dose of clozapine and clinical effect is not high, a threshold plasma level of 350-420 ng mL-1 of clozapine is associated with an increased probability of a good clinical response to the drug. Results vary, however, with the study design. CONCLUSIONS: The data reviewed present a case for increasing the dose of clozapine in non-responsive patients to achieve a plasma level of at least 350-420 ng mL-1. Non-response at these levels, however, should not preclude a further upward titration of dose. This should occur unless (i) clinical response is obtained at a lower dose, (ii) intolerable side effects occur, or (iii) a daily dose of 900 mg is reached.

Antipsychotic Agents↗
PubMed1998

The Erlangen university hospital communication hub--proprietary and standardised communication.

The University of Erlangen-Nuremberg contains 22 hospitals and 11 autonomous medical departments which are spread out over a large area in the city of Erlangen. The necessary connections of these units and their computer based subsystems to each other and to the medical computer centre via fibre optics cables is complete. The internal cabling of the individual units is largely completed. Based on this network the Erlangen communication hub allows medical subsystems of the Erlangen university hospitals to exchange data by two completely different methods. Since 1995 a communication data base, which is implemented using the relational data base system ADABAS D, contains data from the most important hospital systems. This data can be accessed by other medical systems. Thus the communication data base allows subsystems which do not have a standardised interface to implement proprietary system interconnections via access based on SQL. The capabilities of this interconnection are dependent on both the implementation and the data which is made available by the communication data base. This contains mainly basic patient data and the results of tests performed by various laboratory systems. In addition to this proprietary communication system we have since the end of 1996 a communication server which can also handle standardised message formats such as HL7, EDIFACT, DICOM3. Future subsystems which possess standard interfaces will be connected via this server. The connection of the patient management system IS-H and the central laboratory system to the database has been proceeding since the beginning of 1997.

Computer Communication Networks↗
PubMed1997

Systematic screening of the LDL-PLA2 gene for polymorphic variants and case-control analysis in schizophrenia.

Systematic scans of the genome using microsatellite markers have identified chromosome 6p21.1 as a putative locus for schizophrenia in multiply affected families. There is also evidence from a series of studies for a role of abnormal phospholipid metabolism in schizophrenia. In light of these findings, and the role of platelet activating factor in neurotransmission and neurodevelopment, we have examined the LDL-PLA2 (plasma PAF acetylhydrolase, PAF-AH) gene, a serine dependent phospholipase that has been mapped by hybrid mapping to chromosome 6p21.1, as a positional candidate gene for schizophrenia. The gene was systematically screened using SSCP/HD analysis for polymorphisms associated with the disease. Four polymorphic variants were found within the gene and studied in a group of 200 schizophrenic patients and 100 controls. The variant in exon 7 (Iso195Thr) was found to be weakly associated with schizophrenia (p = 0.04) and the variant in exon 11 (Val379Ala) almost reached significance (p = 0.057). After correcting for multiple testing no significant associations were detected. Haplotype analysis combining pairs of polymorphisms also provided no evidence for association of this gene with schizophrenia in our sample of patients.

Alleles↗
PubMed1997

Liver transplantation in Western Australia: improved services to an isolated population.

OBJECTIVE: To assess performance of the Western Australian Liver Transplantation Service in the light of debate about whether small transplant centres can produce optimal outcomes. DESIGN: Review of patient data collected prospectively and confirmed by retrospective casenote review. SUBJECTS: All patients referred to the Western Australian Liver Transplantation Assessment Panel. Those who underwent transplantation at the Western Australian Liver Transplantation Service (to June 1996) were compared with those referred to other transplant centres before the elective service was established in July 1994. OUTCOME MEASURES: Numbers of referrals and transplants; characteristics of the transplantation procedure; and patient outcomes. RESULTS: Annual referrals for liver transplant in Western Australia (WA) increased from 12 (1985-1993) to 41 (July 1994-June 1996), with five deaths on the "activated" list before July 1994, but none after. To June 1996, 30 patients had received 31 transplants by the Western Australian Liver Transplantation Service (two emergency transplants in 1992 and 1993, respectively, and 28 elective transplants and one retransplant after June 1994), with median operation time of 5.5 hours (range, 3-10.5), median red cell transfusion of 4 units (range, 0-55) and median hospital stay of 24 days (range, 12-128). There was no severe primary graft dysfunction. Major complications included hepatic artery thrombosis or stenosis (5 patients, one requiring retransplant), biliary stricture not associated with hepatic artery pathology, bile leak and perihepatic abscess (4 each), and cytomegalovirus infection (3). Patient survival was 83% and graft survival 81% at a mean follow-up of 13 months, compared with 86% and 83%, respectively, at one year for WA patients who received transplants elsewhere before July 1994. CONCLUSIONS: Performance of the Western Australian Liver Transplantation Service compares favourably with national and international standards, and WA patients receiving liver transplants have increased dramatically since the service was established. This supports the viability of committed liver transplantation centres with only 10-15 patients a year and argues the need for nationally decentralised services.

Adolescent↗
PubMed1997

Human mitogen-activated protein kinase kinase 4 as a candidate tumor suppressor.

Mitogen-activated protein kinases function in signal transduction pathways that are involved in controlling key cellular processes in many organisms. A mammalian member of this kinase family, MKK4/JNKK1/SEK1, has been reported to link upstream MEKK1 to downstream stress-activated protein kinase/JNK1 and p38 mitogen-activated protein kinase. This mitogen-activated protein kinase pathway has been implicated in the signal transduction of cytokine- and stress-induced apoptosis in a variety of cell types. Here, we report that two human tumor cell lines, derived from pancreatic carcinoma and lung carcinoma, harbor homozygous deletions that eliminate coding portions of the MKK4 locus at 17p, located approximately 10 cM centromeric of p53. In addition, in a set of 88 human cancer cell lines prescreened for loss of heterozygosity, we detected two nonsense and three missense sequence variants of MKK4 in cancer cell lines derived from human pancreatic, breast, colon, and testis cells. In vitro biochemical assays revealed that, when stimulated by MEKK1, four of the five altered MKK4 proteins lacked the ability to phosphorylate stress-activated protein kinase. Thus, the incidence of coding mutations of MKK4 in the set of cell lines is 6 of 213 (approximately 3%). These findings suggest that MKK4 may function as a suppressor of tumorigenesis or metastasis in certain types of cells.

DNA, Neoplasm↗
PubMed1997

Eating sweet snacks: gender differences in attitudes and behaviour.

This paper reports a study of gender differences in the components of the Theory of Reasoned Action in relation to eating sweet snacks, and the role of these components in predicting sweet-snacking in women and men. Totals of 65 women and 64 men completed questionnaires assessing attitudes and behaviours towards eating sweet snacks. Women were more ambivalent towards eating sweet snacks than men, perceiving eating sweet snacks to be significantly less healthy (t(127) = - 2.43, p < 0.02), and more pleasant (t(127) = 2.52, p < 0.01). There were no statistically significant gender differences in outcome beliefs x evaluations, subjective norms, normative belief x motivation to comply, or in behavioural intention, although some gender differences were found within components. Women scored significantly higher (t(127) = 5.54, p < 0.0005) on restraint items from the Dutch Eating Behaviour Questionnaire, including those on snacking (t(127) = 5.04; p < 0.0005), but did not differ significantly from men on reported frequency of eating sweet snacks. There were gender differences in the predictive power of components of the Theory of Reasoned Action. Women's intentions to eat sweet snacks were predicted by perceived social pressure and attitudes towards sweet snacks. Men's intentions were only predicted significantly by attitudes. It is concluded that men's sweet-snacking is less influenced by social pressure than is women's.

Adolescent↗
PubMed1997

Aneurysmal cyst of soft tissue: report of a case with serial magnetic resonance imaging and biopsy.

We report a case of an extraosseous aneurysmal cyst arising in the left retroclavicular soft tissue of a 29-year-old woman. A magnetic resonance imaging (MRI) scan showed a solid lesion within soft tissue, abutting the clavicle without bone involvement. An incisional biopsy was interpreted as showing osteoclast rich nodular fasciitis with prominent vascularity. A second MRI 5 months later showed intralesional cystic change with areas of increased signal on T2-weighted images, still without any bony defect. The lesion was excised. Histological examination revealed large vascular spaces lined focally by giant cells. The remainder of the lesion was composed of an admixture of spindle cells and osteoclast-like giant cells. The histological and ultrastructural appearance was that of an aneurysmal bone cyst; however, in view of the lack of any bony involvement, a diagnosis of aneurysmal cyst of soft tissue was made. Primary aneurysmal cysts of soft tissue are rare; this is the third well-documented case in the literature, and the first to describe both the MRI appearance and the histological evolution from a solid to multiloculated lesion.

Adult↗
PubMed1997

Enhancement of latent inhibition in the rat by the atypical antipsychotic agent remoxipride.

Latent inhibition (LI) is a behavioural paradigm in which repeated nonreinforced preexposure to a stimulus inhibits the formation of subsequent associations to that stimulus. LI is believed to reflect learning to ignore irrelevant stimuli. Disrupted LI has been suggested as an animal model for the attentional deficits observed in schizophrenia. Remoxipride, a selective dopamine D, antagonist, is an effective antipsychotic with an atypical clinical profile. We investigated the effects of remoxipride (1.0, 5.0, and 10.0 mg/kg) and haloperidol (0.1 mg/kg) administration on LI in rats. A three-stage conditioned emotional response procedure was employed: a) preexposure: preexposed rats received 10 presentations of a flashing light stimulus without reinforcement, and nonpreexposed rats received no exposure: b) conditioning; the preexposed stimulus was paired with a foot shock over a number of trials: c) test: LI was expressed by the extent of suppression of water licking during flashing light presentation. Animals receiving 0.1 mg/kg of haloperidol or 1.0 or 5.0 mg/kg (but not 10.0 mg/kg) of remoxipride treated the preexposed stimulus as irrelevant after a low number of preexposed. These results illustrate that the LI model is equally sensitive to typical and atypical antipsychotics and reemphasises its utility as a test model for detecting the antipsychotic potential of novel drugs.

Animals↗
PubMed1997

Adolescent pregnancy: understanding the impact of age and race on outcomes.

PURPOSE: To determine the independent effects of maternal age and race/ethnicity on poor pregnancy outcomes, with and without controlling for other factors. METHODS: Logistic regression analysis of 54,447 linked birth, fetal death, and infant death certificates in California from 1980-87. RESULTS: Women of young maternal age (10-13 years) are approximately 2.5 times more likely to have a low birthweight infant and 3.4 times more likely to have a preterm birth than women of "prime" childbearing age. African-American women are 1.7 times more likely to have a low birthweight infant, and 2 times more likely to have a preterm birth than their white and Hispanic counterparts. The association of infant death with maternal age and race/ethnicity is statistically significant in the unadjusted models, however, those associations disappear completely when birthweight and gestational age are considered. Interactions between maternal age and race/ethnicity explained very little of the variability for any of the outcomes. CONCLUSIONS: Maternal age at delivery and race/ethnicity are independently and significantly associated with poor pregnancy outcomes such as low birthweight and premature births. However, young maternal age and race/ethnicity do not appear to interact in a manner that produces a differential effect on the birth outcomes assessed in this study. The incidence of infant mortality is unrelated to maternal age or race/ethnicity, after controlling for prematurity and low birthweight, underscoring the importance of intervention efforts aimed at their prevention.

Adolescent↗