Search PubMed⌕ Search

Biomedical subjects

A Lane

Publications and source records attributed to A Lane.

At least 37 records · Page 2Linked to original sources

Evaluation of the analytical performance of the Boehringer Mannheim Elecsys 2010 immunoanalyzer.

OBJECTIVES: We evaluated the analytical performance of the Elecsys 2010 immunoanalyzer (Boehringer Mannheim Canada), which is based on a new detection technology, electrochemical luminescence. DESIGN AND METHODS: We used six representative assays from the initial launch menu of the instrument: thyroid stimulating hormone (TSH), free thyroxine (FT4), troponin T, human chorionic gonadotropin (hCG), carcinoembryonic antigen (CEA), and prostate specific antigen (PSA). Within-run and between-day imprecision were evaluated using pools of human specimens at low, mid and high concentrations. Linearity was evaluated by diluting specimens with high analyte concentrations with specimens that had a low level of this analyte. Carry over and hook effect were investigated using specimens with high concentrations of hCG. Functional sensitivity was studied by running low TSH specimens over 21 daily runs, and by comparing the scatterplot of FT4 as a function of TSH. Over 100 specimens distributed across the analytical range were analyzed with two comparison methods: ES 300 (Boehringer Mannheim Canada) and AxSYM (Abbott Laboratories). RESULTS: Within-run and between-day imprecisions were less than 4% and 10%, respectively, for most assays. All assays were linear over the whole analytical range. Carry over was minimal (< 0.0002%). A hook effect was present for hCG levels greater than 560,000 U/L. The functional sensitivity of the TSH assay was lower than 0.02 mlU/L. Correlation coefficients were all > 0.94. Small proportional errors were observed in comparison studies for the CEA and PSA assays. CONCLUSIONS: The Elecsys 2010 system was shown to have an acceptable analytical performance for the rapid analysis of a wide variety of analytes. The hook effect observed with hCG assay would imply that the laboratory informs the clinicians of the possibility of falsely low values in trophoblastic diseases or that all specimens with values greater than 3000 U/L are reassayed after dilution.

Autoanalysis↗

Neurodevelopmental and neuroprogressive processes in schizophrenia. Antithetical or complementary, over a lifetime trajectory of disease?

The neurodevelopmental model of schizophrenia maintains ascendancy among current etiopathologic perspectives on schizophrenia. However, inconsistencies across studies and the absence thus far of pathognomic brain changes suggest the need for complex conceptualization of neurodevelopmental arrest, including some reconciliation with the competing neurodegenerative model of schizophrenia. This article critically reviews the preponderance of evidence for each model and provides an account of how these may interact or synergize to produce the characteristic clinical expression of schizophrenia.

Age of Onset↗

14-3-3 facilitates Ras-dependent Raf-1 activation in vitro and in vivo.

14-3-3 proteins complex with many signaling molecules, including the Raf-1 kinase. However, the role of 14-3-3 in regulating Raf-1 activity is unclear. We show here that 14-3-3 is bound to Raf-1 in the cytosol but is totally displaced when Raf-1 is recruited to the plasma membrane by oncogenic mutant Ras, in vitro and in vivo. 14-3-3 is also displaced when Raf-1 is targeted to the plasma membrane. When serum-starved cells are stimulated with epidermal growth factor, some recruitment of 14-3-3 to the plasma membrane is evident, but 14-3-3 recruitment correlates with Raf-1 dissociation and inactivation, not with Raf-1 recruitment. In vivo, overexpression of 14-3-3 potentiates the specific activity of membrane-recruited Raf-1 without stably associating with the plasma membrane. In vitro, Raf-1 must be complexed with 14-3-3 for efficient recruitment and activation by oncogenic Ras. Recombinant 14-3-3 facilitates Raf-1 activation by membranes containing oncogenic Ras but reduces the amount of Raf-1 that associates with the membranes. These data demonstrate that the interaction of 14-3-3 with Raf-1 is permissive for recruitment and activation by Ras, that 14-3-3 is displaced upon membrane recruitment, and that 14-3-3 may recycle Raf-1 to the cytosol. A model that rationalizes many of the apparently discrepant observations on the role of 14-3-3 in Raf-1 activation is proposed.

14-3-3 Proteins↗

Spontaneous abnormal involuntary movements in first-episode schizophrenia and schizophreniform disorder: baseline rate in a group of patients from an Irish catchment area.

OBJECTIVE: This study investigated the rate of spontaneous abnormal involuntary movements in a group of patients presenting with a first episode of schizophrenia or schizophreniform psychosis. METHOD: Seventy-nine patients with a first episode of schizophrenia or schizophreniform psychosis who presented to a catchment area psychiatric service over a 3-year period, and who were neuroleptic-naive or had been medicated for less than 1 month, were examined for the presence of involuntary movements with use of the Abnormal Involuntary Movement Scale. RESULTS: Six patients (7.6%) had spontaneous dyskinesia as defined by the criteria of Schooler and Kane, and nine other patients had mild orofacial involuntary movements. The patients with spontaneous dyskinesia had completed significantly fewer years of education than the patients without dyskinesia. Spontaneous involuntary movements were unrelated to age at presentation for treatment. CONCLUSIONS: Spontaneous abnormal involuntary movements were evident among a proportion of patients with first-episode schizophrenia or schizophreniform psychosis at baseline presentation and were associated with reduced educational attainment. This finding supports previous suggestions that abnormal involuntary movements in schizophrenia may be related to the pathophysiology of the illness and therefore cannot be attributed entirely to the adverse effects of neuroleptic medication.

Adult↗

Murine immune responses to Schistosoma haematobium and the vaccine candidate rSh28GST.

Longitudinal studies of Schistosoma haematobium infection in CBA mice revealed a progressive down-regulation of cellular immune responses, as measured by mitogenic and antigenic stimulation of in vitro lymphocyte cultures. Antigen-stimulated production of the Th1 cytokine IFN-gamma by splenocytes increased progressively up to 14 weeks post infection, (four weeks after the onset of parasite egg production), before declining swiftly. Levels of the Th2 cytokine IL-4 in the same cultures remained low until 14 weeks, after which they rose rapidly as IFN-gamma declined. High levels of IL-10 coincided with the peak in IFN-gamma production, suggesting a non Th2-restricted role for this cytokine. Both total and antigen-specific immunoglobulin production confirmed parasite egg deposition as being a major stimulus for host humoral responses. The S. haematobium infection failed to elicit detectable T cell responses to the antifecundity vaccine candidate rSh28GST. However, low levels of antibody were detectable in infected mouse serum and strong IgG and IgA production was induced by vaccination with rSh28GST plus adjuvant.

Animals↗

Activity of plasma membrane-recruited Raf-1 is regulated by Ras via the Raf zinc finger.

Ras recruits Raf to the plasma membrane for activation by a combination of tyrosine phosphorylation and other as yet undefined mechanism(s). We show here that the Raf zinc finger is not required for plasma membrane recruitment of Raf by Ras but is essential for full activation of Raf at the plasma membrane. Membrane targeting cannot compensate for the absence of the zinc finger. One facet of the zinc finger activation defect is revealed using a constitutively activated Raf mutant. Targeting Raf Y340D,Y341D to the plasma membrane increments activity, but full activation requires coexpression with activated Ras. This sensitivity to regulation by Ras at the plasma membrane is abrogated by mutations in the Raf zinc finger but is unaffected by mutation of the minimal Ras binding domain. These data show for the first time that Ras has two separate roles in Raf activation: recruitment of Raf to the plasma membrane through an interaction with the minimal Ras binding domain and activation of membrane-localized Raf via a mechanism that requires the Raf zinc finger.

Animals↗

Performance of the new plasma-compatible Advantage blood glucose test strips.

OBJECTIVE: To establish a plasma calibration curve for the Advantage Blood Glucose System that would permit direct comparison with results provided by clinical laboratories. DESIGN AND METHODS: The initial study involved the comparison between the Advantage whole blood referenced results and the laboratory plasma results. The second study validated the plasma-compatibility of the first new lot of Advantage test strips with this new calibration curve. RESULTS: Plasma and whole blood glucose data, obtained at Hôpital Maisonneuve-Rosemont in Montréal, demonstrated the typical differences between these two sample types. Mathematical correction of the Advantage results eliminated this difference. This new equation was then encoded into the code keys of a new lot of Advantage test strips and a second study was conducted to verify the comparability to laboratory plasma glucose. CONCLUSION: The results for the Advantage Blood Glucose System may now be compared directly with the laboratory plasma or serum glucose results.

Blood Chemical Analysis↗

Nasal airway changes assessed by acoustic rhinometry and mediator release during immediate and late reactions to allergen challenge.

BACKGROUND: We have found that acoustic rhinometry is a reliable means of assessing nasal airway caliber changes during the immediate reaction to nasal allergen challenge of sensitive subjects. Comparison of such changes with symptoms and patterns of mediator release could help in the understanding of mechanisms of immediate and late-phase reactions after allergen challenge and their clinical relevance. METHODS: Nasal minimal cross-sectional area (MCA) was assessed sequentially for 6 hours after two blinded challenges in random order with pollen antigens and buffer diluent in five sensitive human subjects. Comparisons were made with: (1) symptom scores; (2) olfaction changes; and (3) nasal secretion levels of histamine, tryptase, leukotriene C4, serum albumin (a marker of vascular permeability), lactoferrin (a marker of local glandular secretion), and inflammatory cells in nasal scrapings. RESULTS: In four of five subjects there was a significantly greater decrease in MCA after antigen challenge than after diluent challenge, correlating with the degree of subjective nasal congestion. In two of these four subjects there was a prominent second late-phase decrease in MCA at 3 to 5 hours, whereas the MCA was persistently decreased in an additional subject with accompanying subjective congestion. No significant decrease in olfactory acuity occurred. Levels were significantly higher in nasal secretions obtained after antigen challenge than in those obtained after buffer challenge with histamine (9 +/- 2.7 ng/ml vs 1.2 +/- 0.5 ng/ml; p = 0.04); tryptase (95 +/- 83 ng/ml vs 3 +/- 0.9 ng/ml; p = 0.02), leukotriene C4 (5293 +/- 1385 ng/ml vs 578 +/- 183 ng/ml; p = 0.02), and albumin (123 +/- 9 ng/ml vs 19 +/- 1.6 ng/ml; p = 0.005) but not with lactoferrin (4.6 +/- 1.2 ng/ml vs 4.1 +/- 28 ng/ml; p = not significant). Granulocyte exudation was seen after antigen challenge but not after buffer diluent challenge. However, there was not a precise correlation between decreases in MCA with changes in levels of these mediators in individual subjects. CONCLUSIONS: Acoustic rhinometry can quantitatively assess congestion during immediate and late-phase reactions after nasal challenge without significant correlation to the degree of individual inflammatory events assessed.

Acoustics↗

The anthropometric assessment of dysmorphic features in schizophrenia as an index of its developmental origins.

BACKGROUND: Evidence suggests that schizophrenia may be a disorder with origins in early intrauterine mal-development. We have constructed a comprehensive anthropometric scale for the evaluation of dysmorphic features as an index of the nature and timing of developmental disturbance. METHOD: A detailed set of craniofacial and bodily measures was compiled and applied to 174 patients with schizophrenia and 80 matched control subjects. RESULTS: Patients had significantly higher scores on this scale and displayed multiple anomalies of the craniofacial region with an overall narrowing and elongation of the mid-face and lower face. Twelve craniofacial anomalies independently distinguished patients from controls and these variables correctly classified 95% of patients and 80% of control subjects. CONCLUSIONS: This new scale, while procedurally more exacting than the Waldrop scale, more clearly defines the topography of anomalies previously suspected in individuals with schizophrenia. These findings constitute direct evidence for disturbed craniofacial development in schizophrenia and indicate origins in the foetal period during which the characteristic human facial pattern evolves in close association with brain differentiation.

Abnormalities, Multiple↗

Intracellular cytokine expression in whole blood preparations from normals and patients with atopic dermatitis.

In recent years, the importance of characterizing the role of cytokines in a wide range of clinical conditions has resulted in development of new methods to assess cytokine expression in clinical samples. The use of anti-cytokine MoAbs and flow cytometry to detect cytokines intracellularly at the single-cell level has the potential to quantify cytokine production in different diseases. For this technique to be useful in a clinical setting, rapid throughput of clinical samples and a cheap, reliable assay would be required, therefore the development of the above technique using unseparated whole blood samples would be advantageous. Using this technique, only one study to date (Maino et al., 1996) has used unseparated whole blood as the source of cells for detecting intracellular cytokines. In clinical practice, whole blood may be optimal, since this most closely approximates conditions in vivo: as no purification of blood mononuclear cells is required, very little blood is needed to detect a number of cytokines simultaneously in various lymphocyte subpopulations, and the assay can be applied to samples from infants and children. In this study we describe an intracellular cytokine assay using unseparated whole blood from normals. In activated CD8- T cells, IL-2 and interferon-gamma (IFN-gamma) were optimally induced after 10 h stimulation with phorbol 12-myristate acetate (PMA)/ionomycin, and in CD8+ T cells IL-2 was optimally induced after 10 h and IFN-gamma after 6 h. The levels of IL-2 and IFN-gamma in CD8+ and CD8- T cells in four healthy individuals were consistent on four occasions over a 3-month period. In a large group of 34 normal subjects, there was considerable heterogeneity in CD3/IL-2+ (range 9.7-41.3) and CD3/IFN-gamma+ cells (10.1-44), expressed as a percentage of total lymphocytes. In patients with atopic dermatitis (n = 5) there was a significantly decreased percentage of CD3+/CD8+ peripheral blood T cells expressing IFN-gamma and an increased percentage of CD3+/CD8- T cells expressing IL-4 compared with non-atopic dermatitis controls (n = 5). Possible applications of this technique are discussed.

Adult↗

Postnatal depression and elation among mothers and their partners: prevalence and predictors.

BACKGROUND: Correlates and predictors of mood disturbances at 3 days and 6 weeks postpartum were assessed in Irish mothers and their partners. METHOD: The Edinburgh Postnatal Depression Scale (EPDS) and the Highs Scale were used to assess 370 mothers and their partners. Socio-demographic, clinical and obstetric data were collected at patients' first antenatal visit. Factors associated with EPDS scores of > or = 13 and Highs score of > or = 8 were examined. RESULTS: On the EPDS 11.4% of mothers scored > or = 13 at 3 days postpartum and 11% at 6 weeks, while 18.3% of mothers scored > or = 8 on the Highs Scale at 3 days and 9% at 6 weeks. Scores on the EPDS and Highs Scale were interrelated. Factors associated with EPDS scores of > or = 13 at 6 weeks were single status, unemployment, unplanned pregnancy, public status and bottlefeeding. The best predictors of EPDS > or = 13 at 6 weeks were mothers' scores on the EPDS and the Highs Scale at 3 days. Three per cent of partners scored > or = 13 on the EPDS at 3 days postpartum and 1.2% at 6 weeks. CONCLUSIONS: Factors associated with mothers' mood disturbance were readily identifiable and collected routinely at antenatal intake. Mothers' mood within 3 days of delivery was the best predictor of later postnatal depression. Paternal mood disturbance was rare. Certain women may be at increased risk for postnatal mood disturbance and may be amenable to early identification and intervention.

Bipolar Disorder↗

Schizophrenia and neurological soft signs: gender differences in clinical correlates and antecedent factors.

Although it is recognized that patients with schizophrenia demonstrate more neurological soft signs (NSS) than control subjects, the significance and clinical correlates of these signs remain poorly defined. The present study examined 48 patients with DSM-III-R schizophrenia for evidence of NSS. The majority (98%) of patients demonstrated at least one NSS, although the range of scores was wide. There was no relationship between current dosage of neuroleptic medication and NSS score. Among males, there was a significant relationship between NSS and duration of illness. Males whose mothers experienced obstetric complications had higher NSS scores, while females with a family history of schizophrenia exhibited higher scores. These relationships in schizophrenia between NSS and factors of etiological importance wuch as obstetric complications and family history require further evaluation. The present findings are in accord with a body of evidence which suggests that gender may influence the impact of genetic and environmental factors on the neurology of the disorder.

Adolescent↗

Effects of pancreatic spasmolytic Polypeptide (PSP) on epithelial cell function.

Trefoil peptides are expressed near endodermal ulcerations and may modulate epithelial repair. The trefoil pancreatic spasmolytic polypeptide (PSP) was tested for growth activity in vitro on epithelial cells and in vivo following intragastric or intravenous infusion in parenterally fed intact rats. Ion transport was assessed as changes in short-circuit current in rat intestine and adenocarcinoma cells in Ussing chambers. PSP stimulated growth of MCF-7 and Colo-357 cells, but only in the presence of extracellular glutathione (GSH). The effect was attenuated by GSH depletion with buthionine sulphoximine, even in GSH-containing media. When GSH-reduced PSP was carboxymethylated with iodoacetic acid, it still depended on extracellular GSH for its growth effect. Intestinal epithelial proliferation in rats was not affected by either intravenous or intraluminal infusion. PSP had no effect on basal or stimulated ion flux in rat jejunum or epithelial monolayers. The peptide did not compete with 125I-labeled epidermal growth factor for its receptor. [14C]Iodoacetamide treatment of PSP, followed by prolonged tryptic digestion yielded predominantly a 14C-labeled tetrapeptide fragment containing Cys1O4, with a lesser quantity of a 14C-labeled 15-amino-acid peptide containing Cys95 (molar ratio 15:1). GSH may predominantly reduce the Cys6-Cys1O4 terminal disulphide bond in PSP. We conclude that some epithelia may exhibit a growth response to PSP if extracellular GSH is present. Reduction of PSP by GSH is not necessary for this response, suggesting that the trefoil receptor or its signal transduction is GSH sensitive. PSP could assist wound healing by interactions with epithelial cells exposed concurrently to a local high GSH concentration.

Animals↗

Factor VII Arg/Gln353 polymorphism determines factor VII coagulant activity in patients with myocardial infarction (MI) and control subjects in Belfast and in France but is not a strong indicator of MI risk in the ECTIM study.

This paper describes the relationship of factor VII coagulant activity (FVIIc), FVII Arg/Gln353 genotype and risk of myocardial infarction (MI) in the ECTIM (Etude Cas Témoin sur l'Infarctus du Myocarde) study, a multi-centre case-control study on MI. FVIIc was significantly higher in controls from all four centres: Belfast, Lille, Strasbourg and Toulouse, perhaps because elevated FVIIc may predispose to fatal rather than non-fatal MI. Major influences on FVIIc were FVII Arg/Gln353 genotype, triglyceride and cholesterol levels. There was no significant effect of genotype on MI risk however there was a non-significant trend towards increased MI risk in FVII Arg353 homozygotes. Confirming previous observations, FVIIc was highest in FVII Arg353 homozygotes, intermediate in heterozygotes and lowest in FVII Gln353 homozygotes (except Toulouse cases) these differences being highly statistically significant (except Strasbourg cases P = 0.1). In Belfast, consistent with previous findings, there was significant interaction between FVII Arg/Gln353 genotype and triglyceride level in determining FVIIc, whilst this was absent in the French centres. In conclusion, FVII Arg/Gln353 genotype strongly determines FVIIc although neither factor has a strong impact on MI risk in the ECTIM study.

Adult↗

Toxoplasma gondii: appearance of specific markers during the development of tissue cysts in vitro.

Cultures were initiated in Madin-Darby bovine kidney (MDBK) cells from ME49 strain bradyzoites. Specific antibody staining showed that two populations of parasites exist, one being a predominant population of tachyzoites that were positive for the tachyzoite-specific marker SAG1 and negative for the bradyzoite-specific marker P36. All of these parasites expressed the dense granule molecule GRA5, which in larger clusters was seen faintly in the membrane of the parasitophorous vacuole. No rosette formation or monolayer destruction was observed. Also seen was a sub-population of bradyzoites that were positive for P36 and negative for SAG1. Approximately 90% of these parasites expressed the matrix molecule P29. These parasites were also positive for the dense granule molecule GRA5, which was highly concentrated in the wall of the cyst. These bradyzoite clusters contained fewer parasites and were smaller in diameter than those expressing tachyzoite markers.

Animals↗