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Biomedical subjects

J Holland

Publications and source records attributed to J Holland.

At least 37 records · Page 2Linked to original sources

Identification of residues involved in binding of IL5 to betacom using betaIL3 and betacom chimeras.

In mice there are two forms of the beta chain used in the IL3 receptor system, betacom and betaIL3. betacom is used by the IL3, IL5 and GM-CSF receptors whereas betaIL3 is only used in the IL3 receptor. In this work an assay was developed to identify residues of beta1L3 that restrict IL5 activity. It was found that such residues reside within the 2nd CRM of the molecule. Furthermore, when residues in the betaIL3 B'-C' loop were replaced with betacom sequence a form of betaIL3 was produced that was able to respond to IL5. This region is also responsible for IL3 binding to betaIL3 in the absence of alpha chain. It is therefore an important structural motif of betacom and betaIL3 responsible for both ligand interaction and specificity.

Amino Acid Sequence↗

Is quality of life predictive of the survival of patients with advanced nonsmall cell lung carcinoma?

BACKGROUND: Several studies have recently reported on the importance of quality of life (QOL) in predicting the survival of patients with lung carcinoma. To confirm these reports, the relationship between survival and QOL, as measured by the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire and Duke-UNC Social Support Scale, was examined within a group of 206 patients with advanced nonsmall cell lung carcinoma treated in a randomized clinical trial conducted by the Cancer and Leukemia Group B (CALGB 8931). METHODS: Patients completed the EORTC instrument and the Duke-UNC Social Support Scale at baseline in the clinic. The Cox proportional hazards model was used to determine the incremental contribution QOL provided in predicting survival beyond the effect of known clinical prognostic variables. RESULTS: Clinical factors that were jointly predictive of poorer survival included low performance status, nonadenocarcinoma histology, presence of dyspnea, weight loss greater than 5%, albumin level less than 3.5 mg/dL, and adrenal metastases. Univariate analyses showed that patient-reported EORTC subscales describing increased pain, appetite loss, fatigue, lung carcinoma symptoms, poorer overall QOL, and poorer physical functioning predicted significantly poorer survival. Multivariate analyses showed that, after adjustment for clinical factors, overall QOL was not a significant predictor of survival. Rather, the only EORTC subscale of prognostic importance was the pain subscale, in which a 40-point increase was associated with a 27% increase in the hazard rate. CONCLUSIONS: This study did not confirm the prognostic importance of overall QOL. Rather, after adjustment for significant clinical factors, a patient-provided pain report had the greatest prognostic importance.

Adult↗

A critical evaluation of clinical practice guidelines in neonatal medicine: does their use improve quality and lower costs?

Clinical practice guidelines and care pathways have become a focus of quality improvement efforts in Neonatology. Health care administrators believe that using clinical practice parameters reduces health care costs, improves quality of care, and limits malpractice liability. Practice guidelines and surveys of consumer satisfaction have grown in use partly because third-party payers, insurers, and health maintenance organizations, as well as hospital administrators bent on reducing variable costs of care and contracting for capitated care have championed their development, implementation, and monitoring. Overall there is minimal evidence-based medicine to support that neonatal outcomes have benefitted from their implementation, although some studies show affirmative effects in limited populations or in a limited number of centres. For highly autonomous physicians and nurses this standardization of medical decision making may represent a difficult transition into efforts to improve quality, based on evidence-based care, and in some instances into corporate medicine. By realigning the traditional values of patient relationships, including parent involvement, the implementation of guidelines has been fast-tracked in some institutions, without appropriate audit to determine their effectiveness in achieving their goals. However, because guidelines and clinical pathways are here to stay, neonatologists need to think critically about how their content and method of implementation, monitoring and modification may influence medical and nursing teaching and decision making in the future. If guidelines are introduced primarily as a cost savings or containment tool that ignores their impact on the quality of medical care and thereby restricts needed care, then neonatologists must be quick to challenge the potentially damaging and inappropriate use of guidelines and care pathways. Several international efforts are underway to study both the impact of evidence-based guidelines and to determine if they can be imported from one care system into another. Furthermore, there are many medico-legal implications of guideline and clinical pathway implementation that may not favour physicians and other neonatal care practitioners, and leave to hospitals, insurers, and ultimately the courts, decisions regarding evidence-based care. Neonatologists and other practitioners in neonatal care centres should critically analyse the goals of guideline development, implementation and monitoring and should restrict themselves to guideline directed care only at those practices for which there is evidence supporting their implementation and continuous monitoring.

Consumer Behavior↗

Up-regulation of microsphere transport across the follicle-associated epithelium of Peyer's patch by exposure to Streptococcus pneumoniae R36a.

Transport of antigens through the follicle-associated epithelium (FAE) of Peyer's patch (PP) is the critical first step in the induction of mucosal immune responses. We have previously described that short-term exposure to Streptococcus pneumoniae R36a induced dramatic morphological alterations of the FAE in rabbit PP. These results prompted us to investigate whether the pneumococci-induced modifications were accompanied by enhanced ability of the FAE to transport antigens. We addressed this problem by evaluating the ability of the FAE to bind, internalize, and transport fluorescent polystyrene microparticles, highly specific to rabbit M cells, after exposure to S. pneumoniae. Quantitative study revealed a marked increase in the number of microspheres in PP tissues exposed to S. pneumoniae compared to tissues exposed to either phosphate-buffered saline or Escherichia coli DH5alpha as controls. No sign of bacterially induced damage to the epithelial barrier was observed. Further confocal microscopy analysis of the FAE surface showed that a significant increase in the number of cells that showed both morphological and functional features of M cells took place within pneumococci-treated PP tissues. These data provide the first direct evidence that the FAE-specific antigen sampling function may be manipulated to improve antigen and drug delivery to the intestinal immune system.

Animals↗

Effects of chocolate cyst fluid on endometrioma cell growth in culture.

OBJECTIVE: To evaluate the effect of chocolate cyst fluid on the proliferation of cultured human endometrioma cells and to assay the concentration of transforming growth factor-B1 in this fluid. DESIGN: Controlled in vitro study. SETTING: Department of Obstetrics and Gynecology, State University of New York Health Science Center. PATIENT(S): Five women with ovarian endometriomas. INTERVENTION(S): Endometrioma tissue and chocolate fluid from five different patients were entered in this study. MAIN OUTCOME MEASURE(S): Endometrioma cell proliferation in culture with and without chocolate cyst fluid. RESULT(S): Chocolate cyst fluid increased the proliferation of endometrioma cells compared with controls. Also, high concentrations of transforming growth factor-B1 were found in cysts' fluid. CONCLUSIONS: Chocolate cyst fluid has a growth-enhancing effect on endometrioma cells. One promoting growth factor is transforming growth factor-B1.

Cell Count↗

Quantitative intracellular cytokine measurement: age-related changes in proinflammatory cytokine production.

The proinflammatory cytokines play a central role in mediating cellular and physiological responses, and levels may reflect immune system effectiveness. In this study, the effect of ageing on the inflammatory response was examined using a novel method to detect production of the proinflammatory cytokines, i.e. tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-1beta. Peripheral blood mononuclear cells (PBMC) obtained from healthy donors of different ages were incubated for 0, 24, 48 and 72 h with or without phorbol 12-myristate 13-acetate (PMA) stimulation. At each time point these cells were permeabilized and incubated with secondary conjugated FITC MoAbs specific for each cytokine. A flow cytometric system was developed to quantify specific intracellular fluorescence in T cells (CD3+) and monocytes (CD14+). TNF-alpha, IL-6 and IL-1beta production in cell culture supernatants was also measured using ELISAs. In older subjects, flow cytometry detected significant increases in intracellular T cell TNF-alpha and IL-6 (P < 0.05). IL-1beta was not detected in any of the T cell samples. Likewise, the monocytes of older subjects demonstrated increased intracellular levels of all three cytokines, but these increases were not significant (P > 0.05). These changes in intracellular proinflammatory cytokine levels may explain some of the exaggerated inflammatory responses seen in elderly patients.

Adult↗

Hepatitis C genotyping by direct sequencing of the product from the Roche AMPLICOR test: methodology and application to a South Australian population.

The Roche AMPLICOR RT-PCR amplifies a 244 nucleotide sequence within the 5' non coding region (5'NCR) of the viral genome and is a widely used commercial test for the qualitative determination of hepatitis C RNA from sera. This paper describes a routine procedure for the purification of the PCR product, and its use in automated DNA sequencing, for determining the genotype of hepatitis C virus (HCV) isolates. Direct sequencing of the purified product was possible for 86% of samples, whilst 14% required additional amplification using a nested PCR method in order to read the resulting electropherogram. This method of genotyping is considerably less expensive than currently available commercial kits, and is convenient for the increasing number of laboratories that have access to automated DNA sequencers. The highly conserved nature of the 5'NCR limited differentiation of types and subtypes to an extent comparable to commercial HCV typing methods. Using this method on available laboratory samples and on patients about to commence interferon therapy, we found a predominance of genotype 1 (59%) and 3a (31%). Analysis of data on the interferon patients showed the median length of time from first exposure to diagnosis to be significantly longer for patients with genotype 1 than genotype 3a.

Adult↗

Application of multiplex PCR for detection of non-O157 verocytotoxin-producing Escherichia coli in bloody stools: identification of serogroups O26 and O111.

Primers were designed to amplify sequences of verocytotoxin genes and eaeA genes of Escherichia coli O26:H11, O111:H8, and O157:H7 in a multiplex PCR assay. This assay successfully detected E. coli O26:H11 in bloody stool specimens in which other enteric pathogens were not detected by culture-based methods. Rapid assays to detect non-O157:H7 verocytotoxin-producing E. coli is important to improve methods for the etiologic diagnosis of hemorrhagic colitis.

Adhesins, Bacterial↗

Communicating with elders: effects of speaker-listener distance.

As the distance between two communicators increases, weaker sounds of speech become inaudible, conversation becomes more difficult and there is a greater need to resolve communication difficulties. This study investigated the effects of distance on face-to-face social conversation by 27 older adults with hearing impairment, under three listening conditions (without amplification, with personal hearing aids, with a small portable amplifier). Each participant was rated on a 1-5 scale of conversational fluency at distances between 0.5 and 3.0 metres. Results indicate that the subjects conversed more fluently with amplification and at short communication distances. Use of a portable amplifier resulted in high conversational fluency regardless of distance.

Aged↗

A complete YAC contig and cosmid interval map covering the entirety of human Xq21.33 to Xq22.3 from DXS3 to DXS287.

We have produced a physical map that covers the entirety of Xq21.33 to Xq22.3, from DXS3 to DXS287, approximately 15-17 Mb of the proximal long arm of the human X chromosome. This region has already been shown to contain a number of genes involved in genetic disorders, some of which have yet to be cloned. The physical map consists of a contig of 420 yeast artificial chromosome (YAC) clones ordered with respect to 142 DNA markers, approximately one probe every 110 kb. Forty-three YACs from across the contig have been used to isolate 2019 cosmids that have been mapped into 87 intervals, and 667 of these clones are positive for at least 1 single-copy marker. These YACs and cosmids have been used to confirm data from other published contigs that map to the region. The physical map described here constitutes the first step toward a complete transcriptional map of the region.

Chromosome Mapping↗

Elemental iron does repress transferrin, haemopexin and haemoglobin receptor expression in Haemophilus influenzae.

The iron repressible nature of Haemophilus influenzae transferrin binding proteins suggests a regulatory role for elemental iron in their expression. The existence of a Haemophilus ferric uptake repressor (Fur) binding motif identified in the promoter region of both tbpA and tbpB further supports this hypothesis. However, a recent study using brain heart infusion growth medium suggested that transferrin binding protein synthesis in H. influenzae was haem-rather than iron-regulated. The present study re-investigates this observation and using a chemically defined medium, we demonstrate that elemental iron haem or protoporphyrin IX can each regulate Haemophilus influenzae transferrin, haemopexin and haemoglobin receptor expression.

Carrier Proteins↗

Signaling through intercellular adhesion molecule 1 (ICAM-1) in a B cell lymphoma line. The activation of Lyn tyrosine kinase and the mitogen-activated protein kinase pathway.

Intercellular adhesion molecule 1 (ICAM-1) (CD54) is an adhesion molecule of the immunoglobulin superfamily. The interaction between ICAM-1 on B lymphocytes and leukocyte function-associated antigen 1 on T cells plays a major role in several aspects of the immune response, including T-dependent B cell activation. While it was originally believed that ICAM-1 played a purely adhesive role, recent evidence suggests that it can itself transduce biochemical signals. We demonstrate that cross-linking of ICAM-1 results in the up-regulation of class II major histocompatibility complex, and we investigate the biochemical mechanism for the signaling role of ICAM-1. We show that cross-linking of ICAM-1 on the B lymphoma line A20 induces an increase in tyrosine phosphorylation of several cellular proteins, including the Src family kinase p53/p56(lyn). In vitro kinase assays showed that Lyn kinase was activated within 1 min after ICAM-1 cross-linking. In addition, ICAM-1 cross-linking resulted in activation of Raf-1 and mitogen-activated protein kinases, as determined by gel mobility shift. Activation of these kinases may represent important components in the cascade of signals that link ICAM-1 to various ICAM-1-elicited cellular responses. These data confirm the important role of ICAM-1 as a signaling molecule in B cell activation.

Animals↗

Predictors of intrusive thoughts and avoidance in women with family histories of breast cancer.

Having a family history of cancer is an important predictor of lifetime cancer risk. Individuals with family histories of cancer have been reported to experience symptoms of general distress and to have frequent intrusive thoughts and avoidance regarding cancer. To date, little is known about predictors of such distress. A relation between perception of cancer risk and distress has been suggested, but the possibility that prior cancer-related events may contribute to distress in these women has received little attention. The major aim of the study was to examine the contribution of the past experience of the death of a parent from cancer to distress in women at familiar risk for breast cancer. Women with family histories of breast cancer (Risk Group, N = 46) were assessed on the day of their yearly mammography screening and four to eight weeks after normal result notification in order to confirm the generalizability of their distress. Their levels of intrusive thoughts, avoidance, and perceived lifetime risk for breast cancer were significantly higher than those of women with no family histories of cancer who were not undergoing mammography (Comparison Group, N = 43), and this was true on both assessment days. Among the women in the Risk Group, those whose parent(s) had died of cancer had the highest levels of intrusive thoughts, avoidance, and perceived risk. Results suggested that perceived risk mediated the effect of this event on intrusive thoughts and avoidance regarding breast cancer. The findings are discussed in terms of theories of cognitive responses to traumatic and stressful life events. Implications for future research and interventions are discussed.

Adult↗

The immune response to a model antigen associated with PLG microparticles prepared using different surfactants.

The effect of different surfactants on the surface characteristics of poly(D,L-lactideco-glycolide) microparticles prepared by the emulsification/solvent evaporation technique was investigated and the immune response to a protein antigen (OVA) associated with these microparticles was measured. Three surfactants--polyvinyl alcohol (PVA, a conventional stabilizer of PLG microparticles), the non-ionic surfactant, poly(oxyethylene glycerol mono-oleate) [Tagat] and Bile salts (a natural emulsifer)--were used to produce OVA-loaded PLG microparticles. Antigen was detected at the surface of all three types of OVA-loaded microparticles, in amounts in excess of 40% of the total protein load. The levels of specific serum IgG antibody elicited to OVA were significantly higher (P < 0.05) after a single subcutaneous administration of antigen associated with the Bile salts and Tagat formulations compared to the PVA formulation. A strong correlation was revealed between the levels of antibody measured and the magnitude of negative surface charge of the particulate carrier. The pattern of the IgG antibody response to OVA was similar in all three cases, indicating that the degradation rate of the PLG polymer determined the duration of the response. The results demonstrate the potential of using different surfactants to produce PLG microparticles with increased adjuvant activity.

Animals↗

Surgical management of cutaneous infection caused by atypical mycobacteria after penetrating injury: the hidden dangers of horticulture.

We identified two patients in a 12-month period who presented with cutaneous infection and secondary lymph node involvement from atypical mycobacterial infection after minor gardening injuries. One patient had a coinfection with Nocardia asteroides. Both patients required multiple surgical interventions, despite appropriate antibiotic therapy, before resolution of the disease. The course of the infection was characterized by chronic relapses with complete healing at 12 to 18 months after the original injury. The identification and management of this clinical problem are reviewed.

Adult↗