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Biomedical subjects

J S Abrams

Publications and source records attributed to J S Abrams.

At least 19 recordsLinked to original sources
PubMed2003

Fractalkine protein localization and gene expression in mouse brain.

Few chemokines are expressed constitutively in the brain at detectable levels; amongst them is fractalkine. We analyzed the distribution of fractalkine in the mouse brain with the aim of giving a neuroanatomical support to the study of its physiological function. To this end, we carried out an analysis of fractalkine protein localization and gene expression. An anti-fractalkine antibody was produced and used to perform an immunohistochemical study. The results indicated a high level of fractalkine protein in cortex, hippocampus, basal ganglia, and olfactory bulb. In particular, the presence of abundant immunoreactive neurons was observed in layers II, III, V, and VI of the cortex. In the hippocampus, the CA1 region was the most intensely labeled, but immunoreactive neurons were present also in CA2 and CA3, whereas in the basal ganglia, immunoreactive cells were observed in the caudate putamen. Other brain structures such as the brainstem showed a few scattered immunoreactive cells. The presence of fractalkine immunoreactive fibers was revealed only in the olfactory bulb and in the anterior olfactory nuclei. Gene expression study results, obtained by both semiquantitative PCR and in situ hybridization, matched protein localization with the highest levels of fractalkine transcript detected in the hippocampus, cortex, and striatum. The present study showed that fractalkine protein and mRNA are constitutively expressed at a high level in forebrain structure, but are almost absent in the hindbrain. Furthermore, localization at the cellular body level would suggest a paracrine or cell-to-cell interaction role for fractalkine more than a neurotransmission modulatory function.

Amygdala↗
PubMed2001

A critical role for interleukin 18 in primary and memory effector responses to Listeria monocytogenes that extends beyond its effects on Interferon gamma production.

The stimulation of interferon (IFN)-gamma by interleukin (IL)-12 has been shown to provide protection from intracellular pathogens such as Listeria monocytogenes. Tumor necrosis factor (TNF) is also a major player in the resolution of Listeria infections and is suggested to have more global effects than can be explained by the induction of IFN-gamma alone. Since IL-18 synergizes with IL-12 to induce IFN-gamma production by natural killer and T helper (Th)1 cells, we determined its role in responses to Listeria. IL-18 appeared to be even more potent than either IL-12 or IFN-gamma for protection against this pathogen and IL-18 enhanced bacterial clearance in the complete absence of IFN-gamma. Indeed IL-18 was comparable to TNF in its ability to resolve the infection and showed a lowered protective capacity in the absence of TNF. Moreover, IL-18 induced macrophages to secrete both TNF and nitric oxide after a Listeria infection. IL-18 was also essential for optimal IFN-gamma production by antigen-specific T cells. Therefore, IL-18 operates via its effects on both the innate immune response, including macrophages, as well as on Th1 cells, to protect against Listeria.

Animals↗
PubMed2001

Adjuvant therapy for breast cancer--results from the USA consensus conference.

The National Institutes of Health, USA sponsored a Consensus Development Conference on November 1-3, 2000 to review several major questions regarding the adjuvant treatment of breast cancer. A non-governmental group of oncology experts was selected to review clinical trial data and judge the evidence presented by 33 breast cancer researchers. Their conclusions resulted in the following recommendations: (1) Prognostic factors critical for determining risk of recurrence are age, axillary lymph node status, tumor size, histologic type and grade and hormone receptor status. (2) Tamoxifen, administered for 5 years, significantly improves long-term survival for women of all age groups with hormone receptor-positive tumors. Ovarian ablation also prolongs survival in premenopausal women. (3) Multi-agent chemotherapy of 4-6 months duration is associated with an improvement in survival in both hormone receptor-positive and -negative tumors. Anthracycline-containing regimens offer the greatest survival advantage. The role of taxanes is uncertain but they may be useful in selected patients with node-positive tumors. Women with small, node-negative tumors, women over age 70, and those with tumors of favorable histologic subtype (mucinous or tubular) may not require chemotherapy. (4) Adjuvant radiotherapy to the regional lymph nodes and chest wall following mastectomy is indicated for women with 4 or more axillary nodes. (5) Physicians should employ effective visual aids to help them present a complete and balanced view of the absolute benefits versus the side-effects of adjuvant treatments. Important avenues of future research were also discussed and suggestions were made.

Adult↗
PubMed2001

Thermal capsulorrhaphy for instability of the shoulder: concerns and applications of the heat probe.

The use of the heat probe, in my experience, is another instrument to address shoulder instability; however, it will probably not replace suture repairs. Sutures may be used to (1) reattach soft tissue to bone, (2) repair capsule tears lateral to the glenoid, (3) close intervals including the rotator capsular interval, and (4) provide internal fixation to thermally treated tissue. Surgeons need to be able to perform suture repairs to plicate tissues that do not have significant response during the heat application. Most capsular volume reduction procedures require some form of capsular inflammation to stimulate a healing process. The heat probe can be used in a manner similar to the rasp. Sutures will provide internal fixation during the long reparative and remodeling phases. Greater knowledge is necessary regarding techniques, postoperative management, limitation of the procedures, and long-term outcomes. Improvements in application will hopefully reduce complications. Abuse of the heat probe by the inexperienced places its popularity in jeopardy. Following the experts' advice, remaining current in the literature, and improving techniques at laboratory courses will offer the best results to patients.

Catheter Ablation↗
PubMed2000

IL-18 receptors, their role in ligand binding and function: anti-IL-1RAcPL antibody, a potent antagonist of IL-18.

IL-18 is critical in eliciting IFN-gamma production from Th1 cells both in vitro and in vivo. Th1 cells have been implicated in the pathogenesis of autoimmune disorders, making antagonists of IL-18 promising therapeutics. However, specificity and binding characteristics of IL-18R components have only been superficially explored. In this study, we show that IL-1R related protein 1 (IL-1Rrp1) and IL-1R accessory protein-like (IL-1RAcPL) confer responsiveness to IL-18 in a highly specific (no response to other IL-1 ligands) and unique manner (no functional pairing with other IL-1Rs and IL-1R-like molecules). Cotransfection with both receptor components resulted in expression of both low and high affinity binding sites for IL-18 (K:(d) of 11 and 0.4 nM, respectively). We prepared anti-IL-1RAcPL mAb TC30-28E3, which, in contrast to soluble R proteins, effectively inhibited the IL-18-induced activation of NF-kappaB. Quantitative PCR showed that Th1 but not Th2 cells are unique in that they coexpress IL-1Rrp1 and IL-1RAcPL. mAb TC30-28E3 inhibited IL-18-induced production of IFN-gamma by Th1 cells, being at least 10-fold more potent than anti-IL-18 ligand mAb. This study shows that IL-1RAcPL is highly specific to IL-18, is required for high affinity binding of IL-18, and that the anti-IL-1RAcPL mAb TC30-28E3 potently antagonizes IL-18 responses in vitro, providing a rationale for the use of anti-IL-1RAcPL Abs to inhibit Th1-mediated inflammatory pathologies.

Animals↗
PubMed2000

Novel p19 protein engages IL-12p40 to form a cytokine, IL-23, with biological activities similar as well as distinct from IL-12.

A novel sequence discovered in a computational screen appears distantly related to the p35 subunit of IL-12. This factor, which we term p19, shows no biological activity by itself; instead, it combines with the p40 subunit of IL-12 to form a novel, biologically active, composite cytokine, which we term IL-23. Activated dendritic cells secrete detectable levels of this complex. IL-23 binds to IL-12R beta 1 but fails to engage IL-12R beta 2; nonetheless, IL-23 activates Stat4 in PHA blast T cells. IL-23 induces strong proliferation of mouse memory (CD4(+)CD45Rb(low)) T cells, a unique activity of IL-23 as IL-12 has no effect on this cell population. Similar to IL-12, human IL-23 stimulates IFN-gamma production and proliferation in PHA blast T cells, as well as in CD45RO (memory) T cells.

Amino Acid Sequence↗
PubMed1999

APCs express DCIR, a novel C-type lectin surface receptor containing an immunoreceptor tyrosine-based inhibitory motif.

We have identified a novel member of the calcium-dependent (C-type) lectin family. This molecule, designated DCIR (for dendritic cell (DC) immunoreceptor), is a type II membrane glycoprotein of 237 aa with a single carbohydrate recognition domain (CRD), closest in homology to those of the macrophage lectin and hepatic asialoglycoprotein receptors. The intracellular domain of DCIR contains a consensus immunoreceptor tyrosine-based inhibitory motif. A mouse cDNA, encoding a homologous protein has been identified. Northern blot analysis showed DCIR mRNA to be predominantly transcribed in hematopoietic tissues. The gene encoding human DCIR was localized to chromosome 12p13, in a region close to the NK gene complex. Unlike members of this complex, DCIR displays a typical lectin CRD rather than an NK cell type extracellular domain, and was expressed on DC, monocytes, macrophages, B lymphocytes, and granulocytes, but not detected on NK and T cells. DCIR was strongly expressed by DC derived from blood monocytes cultured with GM-CSF and IL-4. DCIR was mostly expressed by monocyte-related rather than Langerhans cell related DC obtained from CD34+ progenitor cells. Finally, DCIR expression was down-regulated by signals inducing DC maturation such as CD40 ligand, LPS, or TNF-alpha. Thus, DCIR is differentially expressed on DC depending on their origin and stage of maturation/activation. DCIR represents a novel surface molecule expressed by Ag presenting cells, and of potential importance in regulation of DC function.

Amino Acid Sequence↗
PubMed1999

Tetrameric complexes of human histocompatibility leukocyte antigen (HLA)-G bind to peripheral blood myelomonocytic cells.

The nonclassical MHC class I molecule human histocompatibility leukocyte antigen (HLA)-G is selectively expressed on fetal trophoblast tissue at the maternal-fetal interface in pregnancy. It has long been suggested that HLA-G may inhibit maternal natural killer (NK) cells through interaction with particular NK cell receptors (KIRs). To investigate interactions of HLA-G, we constructed phycoerythrin-labeled tetrameric complexes of HLA-G refolded with a self-peptide. These HLA-G tetramers failed to bind to NK cells and cells transfected with CD94/NKG2 and killer immunoglobulin-like NK receptors. In contrast, HLA-G tetramers did bind to peripheral blood monocytes, staining a CD16(+)CD14(mid) subset with greater intensity. On transfectants, HLA-G tetramers bound to inhibitory immunoglobulin-like transcript (ILT)2 and ILT4 receptors. However, staining in the presence of antibodies reactive with ILT receptors revealed that the interaction of HLA-G tetramers with blood monocytes was largely due to binding to ILT4. These results suggest that the primary role of HLA-G may be the modulation of myelomonocytic cell behavior in pregnancy.

Animals↗
PubMed1998

North American Adjuvant Breast Cancer Trials.

The National Cancer Institutes in the United States and Canada sponsor Cooperative Groups to perform randomized trials in distinct subsets of patients with early breast cancer. In women with low-risk ductal carcinoma in situ (DCIS), ongoing studies are evaluating the role of adjuvant breast irradiation. For those with low-risk, node-negative invasive tumors, efforts have been directed to improving the efficacy of tamoxifen, while in high-risk patients the focus has been on improving chemotherapy. The roles of dose intensity and dose density have been evaluated at dose levels requiring either G-CSF or stem cells. More recently, the introduction of taxanes into adjuvant regimens has been a major area of investigation. Following treatment with doxorubicin-cyclophosphamide (AC), patients have been randomized to receive paclitaxel or no further therapy in INT 0148 and NSABP B-28 and to receive docetaxel in NSABP B-27. For women with 4-9 involved nodes, sequential treatment A(doxorubicin)-T(paclitaxel)-C(cyclophosphamide) with G-CSF is being compared to AC x 4 followed by high-dose chemotherapy with stem cell support. Cooperative Group trials have been critical in defining the standard of care in the past, and successful completion of these new trials is essential for further progress against breast cancer.

Breast Neoplasms↗
PubMed1997

Similar RANTES levels in healthy and asthmatic airways by immunoassay and in situ hybridization.

To determine if RANTES expression is unregulated in the airways of asthmatic subjects, we performed bronchial mucosal biopsies and airway lavage in seven atopic asthmatic subjects and eight healthy subjects. Immunohistochemistry was used to reveal RANTES protein expression in the airway biopsies. An ELISA was used to quantitate RANTES in lavage. In three subjects in each group, we also used in situ hybridization to reveal mRNA for RANTES in airway biopsies. We found that the mean (+/- SD) percent expression for RANTES in the epithelium and submucosa was 26 +/- 9% and 26 +/- 10% in the asthmatic and healthy tissue samples, respectively. RANTES mRNA was demonstrable in the bronchial mucosa of both healthy and asthmatic subjects, predominantly in the epithelial cells but also in the submucosa. We also found that there was no significant difference in the median RANTES concentrations between the groups (healthy: 2.9 pg/ml [range: 0.0 to 28.7 pg/ml]; asthma: 1.8 pg/ml [range: 0.0 to 82.1 pg/ml], p > 0.05) despite a trend for higher concentrations of eosinophil cationic protein (ECP) in the asthmatic group (p = 0.08). In summary, this study confirms that cells in airway mucosal tissue produce RANTES but that the level of production in mild stable asthma is not different from that of healthy control subjects.

Adult↗
PubMed1996

High-dose chemotherapy for breast cancer.

The role of high-dose chemotherapy in the management of women with breast cancer remains one of the most controversial issues in oncology. During the past decade, numerous pilot studies have shown the feasibility of administering high-dose chemotherapy followed by autologous bone marrow transplantation or peripheral blood stem-cell transplantation (referred to as high-dose chemotherapy) to women with metastatic disease. However, it appears that survival improves in few treated patients. This treatment strategy is now being evaluated in the adjuvant setting in patients who are at high risk for developing recurrent disease. The National Cancer Institute has selected two randomized, adjuvant breast cancer trials for its High-Priority Clinical Trials Program. These trials are comparing conventional-dose chemotherapy with high-dose chemotherapy in patients in the early stages of breast cancer who are at high risk for disease recurrence. This paper focuses on the rationale for the randomized studies evaluating adjuvant high-dose chemotherapy in the early stages of breast cancer and reviews the efforts to overcome physician and patient biases so that the trials can be completed.

Antineoplastic Agents↗
PubMed1996

Human placental cytotrophoblasts produce the immunosuppressive cytokine interleukin 10.

The mechanism by which the mammalian mother accepts the implanting fetus as an allograft remains unexplained, but is likely to be the result of a combination of factors. Mononuclear cytotrophoblasts, the specialized fetal cells of the placenta that invade the uterus, play an important role. These cells express HLA-G, an unusual major histocompatibility complex class I-B molecule, and secrete cytokines and pregnancy-specific proteins that can regulate immune function. We investigated whether cytotrophoblasts secrete interleukin 10 (IL-10), a cytokine that potently inhibits alloresponses in mixed lymphocyte reactions. Cytotrophoblasts from all stages of pregnancy produced IL-10 in vitro, but neither placental fibroblasts nor choriocarcinoma (malignant trophoblast) cell lines did so. Spontaneous IL-10 production averaged 650, 853, and 992 pg/10(6) cells in the first, second, and third trimesters of pregnancy, respectively. IL-10 secretion dropped approximately 10-fold after the first 24 h of culture, and was paralleled by a decrease in messenger RNA. IL-10 messenger RNA was detected in biopsies of the placenta and the portion of the uterus that contains invasive cytotrophoblasts, suggesting that this cytokine is also produced in vivo. IL-10 secreted by cytotrophoblasts in vitro is bioactive, as determined by its ability to suppress interferon gamma production in an allogeneic mixed lymphocyte reaction. We conclude that human cytotrophoblast IL-10 may be an important factor that contributes to maternal tolerance of the allogeneic fetus.

Base Sequence↗
PubMed1996

A role for stem cell factor (SCF): c-kit interaction(s) in the intestinal tract response to Salmonella typhimurium infection.

Cholera toxin (CT) has been shown to induce stem cell factor (SCF) production in mouse ligated intestinal loops. Further, SCF interaction(s) with its receptor (c-kit) was shown to be important for the intestinal tract secretory response after CT exposure. In this study, we have investigated whether SCF production is induced in the intestinal tract after exposure to Salmonella typhimurium and whether this production could be an important intestinal tract response to Salmonella infection. Using a mouse ligated intestinal loop model, increased levels of SCF mRNA were detected at 2-4 h post-Salmonella challenge. Intestinal fluid obtained from Salmonella-challenged loops contained high levels of SCF by ELISA. Human and murine intestinal epithelial cell lines were also shown to have increased levels of SCF mRNA after exposure to Salmonella. Inhibition of Salmonella invasion of epithelial cells was shown to be one potentially important role for SCF:c-kit interactions in host defense to Salmonella infection. Pretreatment of human or murine intestinal cell lines with SCF resulted in a cellular state that was resistant to Salmonella invasion. Finally, mice having mutations in the white spotting (W) locus, which encodes the SCF-receptor (c-kit), were significantly more susceptible to oral Salmonella challenge than their control littermates. Taken together, the above results suggest that an important intestinal tract response to Salmonella infection is an enhanced production of SCF and its subsequent interactions with c-kit.

Animals↗
PubMed1996

High levels of spontaneous and parasite antigen-driven interleukin-10 production are associated with antigen-specific hyporesponsiveness in human lymphatic filariasis.

To determine whether counterregulation by interleukin (IL)-10 plays a role in the generation or maintenance of the antigen-specific hyporesponsiveness seen in asymptomatic microfilaremic (MF) patients, parasite antigen (PAg)- and nonparasite antigen (NPAg)-driven IL-10 production by peripheral blood mononuclear cells (PBMC) was studied in 10 MF patients and in ll patients with chronic lymphatic pathology (CP). PBMC from MF patients spontaneously secreted 10-fold more IL-10 than did PBMC from patients with CP. PAg also induced significantly more IL-10 production by PBMC from CP patients. There was a negative correlation between PAg driven IL-10 production by PBMC and PAg-specific T cell proliferation in the MF group. IL-10 secretion by plastic adherent cells from MF persons was higher in response to PAg than NPAg, whereas IL-6 and tumor necrosis factor-alpha secretion were equivalent for PAg and NPAg, suggesting that PAg preferentially induces IL-10 secretion in these cells. Thus, PAg-induced IL-10 likely plays an important role in down-regulating antigen-specific proliferative responses in MF patients.

Adolescent↗
PubMed1996

Interleukin-3 in bronchial biopsies from nonasthmatics and patients with mild and allergen-induced asthma.

Cytokines, such as interleukin-3 (IL-3), have been suggested to play an important role in mediating the increased number of airway eosinophils and metachromatic cells in patients with even mild asthma. We used immunohistochemistry to determine the presence of IL-3 protein in bronchial biopsies from nonasthmatics (n = 10) and subjects with mild (n = 8) and allergen-induced (n = 7) asthma. We also examined whether IL-3 was related to airway eosinophil number and activation, the number of airway metachromatic cells, or airway function. We found that the number and activation of eosinophils and the number of metachromatic cells were increased in the airways of asthmatics, compared with nonasthmatics, with further increases evident after allergen challenge. IL-3 protein was localized primarily to the epithelium in nonasthmatic and asthmatic subjects, with no difference apparent between groups or after allergen inhalation challenge. The extent of staining for IL-3 in the tissue was not correlated with eosinophil number or activity, metachromatic cell number, airway responsiveness, or the severity of the late asthmatic response. This study provides the first demonstration of IL-3 protein localization in bronchial tissue from human airways. The results suggest that the increases in eosinophils and metachromatic cells associated with mild and allergen-induced asthma occur independent of IL-3.

Adult↗