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Publication
Journal: Journal of Infectious Diseases
June/21/2010
Abstract
Visceral leishmaniasis is characterized by severe immunosuppression of the host cell, resulting in loss of the proinflammatory response. Toll-like receptor 2 (TLR2) is involved in myriad disease forms, including visceral leishmaniasis. During Leishmania donovani infection, the parasite modulates TLR2 to suppress interleukin 12 production, indicating the possible involvement of TLR2 in regulation of the immune response against L. donovani infection. Arabinosylated lipoarabinomannan (Ara-LAM) possesses immunomodulatory properties and induces proinflammatory responses via induction of TLR2-mediated signaling. Here, we found that pretreatment of L. donovani-infected macrophages with Ara-LAM caused a significant increase in TLR2 expression along with the activation of TLR2-mediated downstream signaling, facilitating active nuclear translocation of nuclear factor kappaB. These events culminated in up-regulation of the proinflammatory response, which was abrogated by treatment with TLR2-specific small interfering RNA. In vivo experiments were also suggestive of Ara-LAM playing a long-term protective role. This study demonstrates that Ara-LAM confers protection against leishmanial pathogenesis via TLR2 signaling-mediated induction of the proinflammatory response.
Publication
Journal: Journal of Pathology
July/18/2004
Abstract
The interstitial lung disease lymphangioleiomyomatosis (LAM) is characterized by diffuse proliferation of smooth muscle cells (SMCs), which in many patients show TSC2 (tuberin) gene mutations, in addition to thickening of interstitial tissues, loss of alveoli, and the development of cystic spaces. While SMC proliferation is the defining feature of LAM, a significant proportion of LAM lung tissue consists of expanded interstitial connective tissue that is negative for smooth muscle actin and TSC2 mutations. The importance of this actin-negative interstitial tissue to the pathophysiology of LAM is not clear. The present study has determined the contribution of this interstitial tissue to LAM lung volume by morphometric analysis and has examined its cell and matrix proteoglycan composition by immunohistochemistry. Lung tissue from nine LAM patients and four control subjects was examined. LAM lung contained twice as much interstitial tissue as control lung (27% versus 13% of total lung volume), with SMCs accounting for less than 25% of the interstitial volume. Areas of interstitial tissue stained strongly for the matrix proteoglycans versican and biglycan. Decorin was prominent in association with collagen bundles. SMCs did not stain, or stained lightly, for proteoglycans. Versican and biglycan deposits were closely associated with actin-negative interstitial fibroblasts identified by prolyl 4-hydroxylase immuno-staining. Comparatively normal alveolar walls in LAM lung also stained strongly for versican and had a reduced elastin content. Thickened interstitial regions contained significant amounts of elastin (approximately 13% of interstitial volume) but with fibres in disorganized patterns. Elastic fibres were absent from areas that stained strongly for versican and biglycan. These areas also showed weak staining for elastin binding protein (EBP), consistent with proteoglycan-induced shedding of EBP and inhibition of elastic fibre formation. These findings point to a significant contribution from matrix proteoglycans to the expanded and remodelled interstitial lung tissue of LAM patients.
Publication
Journal: Canadian Journal of Veterinary Research
October/14/1991
Abstract
The objective of this study was to evaluate the performance of the lipoarabinomannan antigen enzyme-linked immunosorbent assay (LAM-ELISA), carbohydrate antigen complement fixation (CH-CFT), and protein D antigen agar gel immunodiffusion (D-AGID) tests for bovine paratuberculosis, relative to histopathology, and to culture and isolation of Mycobacterium paratuberculosis from tissues and feces. Samples for test evaluation were collected from four sources including blood and tissues from 400 cull cows at three abattoirs in Ontario, blood and feces from a paratuberculosis survey of cattle from 120 dairy farms in Ontario, a serum bank containing samples from cattle from Ontario and Québec, and a bank of sera from cattle from Pennsylvania and the northeastern United States. The data were analyzed using receiver operator characteristic curves, estimates of relative sensitivity and specificity, and kappa statistics of agreement between tests. The LAM-ELISA performed significantly better than both the CH-CFT and the D-AGID tests. The LAM-ELISA was better at predicting fecal shedding status than tissue infection. However, the LAM-ELISA also had limitations. When interpreted as positive or negative (+/-), at a critical optical density of 0.675, its sensitivity and specificity relative to bacteriology were 49% and 87% respectively. Although the serological tests examined in this study provided some information, they did not predict well the infection status of individual animals.
Publication
Journal: Beilstein Journal of Organic Chemistry
July/13/2011
Abstract
N-Arylated aliphatic and aromatic amines are important substituents in many biologically active compounds. In the last few years, transition-metal-mediated N-aryl bond formation has become a standard procedure for the introduction of amines into aromatic systems. While N-arylation of simple aromatic halides by simple amines works with many of the described methods in high yield, the reactions may require detailed optimization if applied to the synthesis of complex molecules with additional functional groups, such as natural products or drugs. We discuss and compare in this review the three main N-arylation methods in their application to the synthesis of biologically active compounds: Palladium-catalysed Buchwald-Hartwig-type reactions, copper-mediated Ullmann-type and Chan-Lam-type N-arylation reactions. The discussed examples show that palladium-catalysed reactions are favoured for large-scale applications and tolerate sterically demanding substituents on the coupling partners better than Chan-Lam reactions. Chan-Lam N-arylations are particularly mild and do not require additional ligands, which facilitates the work-up. However, reaction times can be very long. Ullmann- and Buchwald-Hartwig-type methods have been used in intramolecular reactions, giving access to complex ring structures. All three N-arylation methods have specific advantages and disadvantages that should be considered when selecting the reaction conditions for a desired C-N bond formation in the course of a total synthesis or drug synthesis.
Publication
Journal: Antonie van Leeuwenhoek
September/8/2008
Abstract
The genus Corynebacterium is part of the phylogenetic group nocardioform actinomycetes, which also includes the genus Mycobacterium. Members of this phylogenetic group have a characteristic cell envelope structure, which is dominated by complex lipids and amongst these, lipoglycans are of particular interest. The disruption of NCgl2106 in C. glutamicum resulted in a mutant devoid of monoacylated phosphatidyl-myo-inositol dimannoside (Ac(1)PIM(2)) resulting in the accumulation of Ac(1)PIM(1) and cessation of phosphatidyl-myo-inositol (PI) based lipomannan (Cg-LM, now also termed 'Cg-LM-A') and lipoarabinomannan (Cg-LAM) biosynthesis. Interestingly, SDS-analysis of the lipoglycan fraction from the mutant revealed the synthesis of a single novel lipoglycan, now termed 'Cg-LM-B'. Further chemical analyses established the lipoglycan possessed an alpha-D: -glucopyranosyluronic acid-(1 ->> 3)-glycerol (GlcAGroAc(2)) based anchor which was then further glycosylated by 8-22 mannose residues, with Man(12-20)GlcAGroAC(2) molecular species being the most abundant, to form a novel lipomannan structure (Cg-LM-B). The deletion of NCgl2106 in C. glutamicum has now provided a useful strain, in addition with a deletion mutant of NCgl0452 in C. glutamicum for the purification of Cg-LM-A and Cg-LM-B. Interestingly, both Cg-LM species induced a similar production of TNF-alpha by a human macrophage cell line suggesting that the phospho-myo-inositol residue of the PI-anchor does not play a key role in lipoglycan pro-inflammatory activity.
Publication
Journal: Genomics
January/15/1991
Abstract
Tuberous sclerosis (TSC) is an autosomal dominant disorder characterized by widespread hamartosis. Preliminary evidence of linkage between the TSC locus and markers on chromosome 9q34 was established, but subsequently disputed. More recently, a putative TSC locus on chromosome 11 has been suggested and genetic heterogeneity seems likely. Here we describe an approach combining multipoint linkage analysis and heterogeneity tests that has enabled us to obtain significant evidence for locus heterogeneity after studying a relatively small number of families. Our results support a model with two different loci independently causing the disease. One locus (TSC1) maps in the vicinity of the Abelson oncogene at 9q34 and a second locus (TSC2) maps in the region of the anonymous DNA marker Lam L7 and the dopamine D2 receptor gene at 11q23.
Publication
Journal: Journal of Viral Hepatitis
June/5/2006
Abstract
Switching to adefovir (ADV) monotherapy is effective in patients with lamivudine (LAM)-resistant hepatitis B virus (HBV) mutations (rtM204 I/V). However, it was recommended to continue LAM therapy for months after starting ADV therapy for safety concern. The safety and efficacy of switching to ADV monotherapy was examined in compensated and decompensated patients with liver cirrhosis. The clinical, biochemical and virological responses were compared between ADV monotherapy in 18 cirrhotic patients and ADV add-on LAM therapy in 10 comparable cirrhotic patients with LAM-resistant rtM204 I/V. After switching to ADV monotherapy, Child-Pugh's score, serum alanine aminotransferase (ALT), bilirubin, albumin and HBV DNA levels improved significantly (P < 0.01). Serum HBV DNA response, defined as HBV DNA decreased to below 10(5) copies/mL or>> or =2 log(10) reduction form baseline, was achieved in all patients. A transient ALT flare without concurrent changes in serum bilirubin or prothrombin time was observed in only two patients (11%). The efficacy and safety profile was similar to those with ADV add-on LAM therapy. In conclusion, switching to ADV monotherapy after emergence of LAM-resistant rtM204 I/V is effective and safe in cirrhotic patients, even in those with hepatic decompensation. To stop LAM and switch to ADV in patients with breakthrough is a reasonably safe and cost-effective approach.
Publication
Journal: World Journal of Gastroenterology
April/3/2014
Abstract
OBJECTIVE
To compare the effects of entecavir (ETV) and lamivudine (LAM) for the treatment of hepatitis B decompensated cirrhosis using a meta-analysis.
METHODS
We conducted a literature search for all eligible studies published prior to May 30, 2013 using PUBMED, MEDLINE, EMBASE, the China National Knowledge Infrastructure (CNKI), the VIP database, the Wanfang database and the Cochrane Controlled Trial Register. Randomized controlled trials (RCTs) comparing ETV with LAM for the treatment of hepatitis B decompensated cirrhosis were included. The data were analyzed with Review Manager Software 5.0.2. We used RR as an effect measure, and reported its 95%CI. The meta-analysis was performed using either a fixed-effect or random-effect model, based on the absence or presence of significant heterogeneity. Two reviewers assessed the risk of bias and extracted data independently and in duplicate. The analysis was executed using the main outcome parameters including hepatitis B virus (HBV) DNA undetectability, HBV DNA level, hepatitis B e antigen (HBeAg) seroconversion, alanine aminotransferase (ALT) level, albumin level, total bilirubin (TBIL) level, prothrombin time activity (PTA) level, Child-Turcotte-Pugh (CTP) score, mortality, drug-resistance, and adverse reactions. Meta-analysis of the included trials and subgroup analyses were conducted to examine the association between pre-specified characteristics and the therapeutic effects of the two agents.
RESULTS
Thirteen eligible trials (873 patients in total) were included and evaluated for methodological quality and heterogeneity. Of these studies, all had baseline comparability, 12 of them reported baseline values of the two treatment groups in detail. Following various treatment durations (12, 24, 36, 48 and>> 48 wk), both ETV and LAM significantly reduced HBV DNA level, however, reductions were greater in the ETV group (MD = -0.66, 95%CI: -0.83-0.50, P < 0.00001), (MD = -0.93, 95%CI: -1.36-0.51, P < 0.0001), (MD = -1.4, 95%CI: -1.78-1.01, P < 0.00001), (MD = -1.18, 95%CI: -1.90-0.46, P = 0.001), (MD = -0.14, 95%CI: -0.17-0.11, P < 0.00001, respectively). At 12, 24 and 48 wk of treatment, ETV had a significant effect on the rate of HBV DNA undetectability (RR = 1.55, 95%CI: 1.22-1.99, P = 0.0004), (RR = 1.25, 95%CI: 1.13-1.38, P < 0.0001), (RR = 1.2, 95%CI: 1.10-1.32, P < 0.0001, respectively). Although HBeAg seroconversion in the ETV group was more pronounced than that in the LAM group at 24 wk (27.90% vs 26.19%) and 48 wk (31.52% vs 25.00%) of treatment, there was no statistically significant difference between them (RR = 1.49, 95%CI: 0.98-2.28, P = 0.07), (RR = 1.27, 95%CI: 0.98-1.65, P = 0.07, respectively). Following various treatment durations, both the ETV group and the LAM group showed significantly improved liver function (ALT, AIB, TBIL, PTA and CTP levels) and reduced mortality (ETV 6.37%, LAM 7.89%). The effects in the ETV group (0.33%) were statistically lower than those in the LAM group (14.33%) regarding the rate of drug-resistance (RR = 0.1, 95%CI: 0.04-0.24, P ≤ 0.00001). In addition, no severe adverse reactions were observed in the two treatment groups.
CONCLUSIONS
ETV and LAM significantly improved liver function and reduced mortality. Both drugs produced similar serological responses, and were safe and well tolerated. However, ETV resulted in a better virological response and lower drug-resistance, but is more expensive.
Publication
Journal: Bulletin of Entomological Research
April/13/2011
Abstract
The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.
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Publication
Journal: Biochemistry
January/10/2008
Abstract
The mycobacterial D-arabinofuran is a common constituent of both cell wall mycolyl-arabinogalactan (AG) and the associated lipoarabinomannan (LAM), and is thus accorded critical structural and immunological roles. Despite a well-recognized importance, progress in understanding its full structural characteristics beyond the nonreducing terminal motifs has hitherto been limited by available analytical tools. An endogenous arabinanase activity recently isolated from Mycobacterium smegmatis was previously shown to be capable of releasing large oligoarabinosyl units from AG. Advanced tandem mass spectrometry utilizing both low and high energy collision induced dissociation now afforded a facile way to map and directly sequence the digestion products which were dominated by distinctive Ara18 and Ara19 structural units, together with Ara7 and lesser amount of Ara11 and Ara12. Significantly, evidence was obtained for the first time which validated the linkages and branching pattern of the previously inferred Ara22 structural motif of AG, on which the preferred cleavage sites of the novel arabinanase could be localized. The established linkage-specific MS/MS fragmentation characteristics further led to identification of a galactosamine substituent on the C2 position of a portion of the internal 3,5-branched Ara residue of the AG of Mycobacterium tuberculosis, but not that of the nonpathogenic, fast growing M. smegmatis.
Publication
Journal: Journal of Immunology
September/11/1995
Abstract
The initial phagocytic interaction between Mycobacterium tuberculosis and macrophages (M phi) in the lung is probably nonopsonic, which would mean that M phi receptors will bind directly to bacterial ligands without the involvement of serum opsonins. Lipoarabinomannan (LAM) is a major component of the cell wall of mycobacteria. The possibility that LAM is involved in the nonopsonic binding of M. tuberculosis to M phi was investigated by using competitive inhibition assays. LAM inhibited binding of M. tuberculosis to murine peritoneal M phi in a dose-dependent manner. LAM also inhibited the binding of Mycobacterium avium and Mycobacterium bovis BCG to M phi. Phosphatidylinositol mannoside and lipomannan have the same phosphatidylinositol (PI) moiety as LAM, but differ in their glycosylation patterns. Both molecules inhibited binding of M. tuberculosis to M phi. Deacylation of LAM abrogated its capacity to inhibit binding of M. tuberculosis to M phi. These observations indicated that it was the PI moiety of LAM that was important in mediating its inhibitory properties. In support of this hypothesis, commercial PI was shown to inhibit the binding of M. tuberculosis to M phi. Our results suggest that cellfree LAM is able to inhibit the binding of mycobacteria to M phi, but that it does not do so by competing with any interaction between M phi receptors and cell-associated LAM, because the PI end of the molecule is believed to be anchored in the bacterial plasma membrane, and therefore not available as a ligand on the cell surface. However, LAM that is released from M. tuberculosis in the course of its active replication during infection may be able to interfere with the phagocytic clearance of mycobacteria.
Publication
Journal: Journal of Hepatology
June/30/2013
Abstract
OBJECTIVE
Fetal safety of antiviral therapies is important given the long-term treatment of women with chronic hepatitis B (CHB) infection who may become pregnant. We analyzed neonatal safety data from the Antiretroviral Pregnancy Registry (APR), the largest safety database in pregnancy for antivirals used for HIV and CHB.
METHODS
Data were extracted from APR cases prospectively enrolled between 1989 and 2011. Primary outcomes were major birth defects rates with exposure to all antivirals, individual classes, and drugs compared to population-based controls. Relevant to CHB, only lamivudine (LAM) and tenofovir disoproxil fumarate (TDF) had sufficient individual data for review (≥200 cases).
RESULTS
Of 13,711 cases analyzed, the overall birth defect prevalence (2.8%, 95% CI 2.6-3.1%) was comparable to Centers for Disease Control population-based data (2.72%, 2.68-2.76%, p=0.87) and two prospective antiretroviral exposed newborn cohorts (2.8%, 2.5-3.2%, p=0.90 and 1.5%, 1.1-2.0%, p<0.001). The birth defects prevalence between first and second/third trimesters exposure was similar (3.0% vs. 2.7%). No increased risk of major birth defects with LAM or TDF exposure compared to population-based controls was observed. No specific pattern of major birth defects was observed for individual antivirals or overall.
CONCLUSIONS
No increased risk of major birth defects including in non-live births was observed for pregnant women exposed to antivirals relevant to CHB treatment overall or to LAM or TDF compared to population-based controls. Continued safety and efficacy reporting on antivirals in pregnancy are essential to inform patients on their risks and benefits during pregnancy.
Publication
Journal: Infection and Immunity
April/23/1997
Abstract
PTX3 is a prototypic long pentraxin composed of a C-terminal domain similar to those of classical pentraxins (e.g., C reactive protein) and an unrelated N-terminal portion. PTX3 is expressed in a variety of cell types, notably mononuclear phagocytes and endothelial cells, after exposure to the inflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha). The present study was designed to assess whether mycobacterial components were able to induce expression and production of PTX3. Mycobacterial lipoarabinomannan (LAM) induced expression of PTX3 mRNA in human peripheral blood mononuclear cells. The non-mannose-capped version of lipoarabinomannan (AraLAM) was considerably more potent than the mannose-capped version ManLAM or the simpler version phosphatidylinositol mannoside. Among mononuclear cells, monocytes were responsible for LAM-induced PTX3 mRNA expression. Whole mycobacteria (Mycobacterium bovis BCG) strongly induced PTX3 expression. Pretreatment with actinomycin D abolished LAM-induced PTX3 expression, whereas cycloheximide only partially reduced the expression. LAM-induced PTX3 expression was associated with the production of immunoreactive PTX3. IL-10 and IL-13 did not inhibit the induction of PTX3 by LAM. Under the same conditions, these anti-inflammatory cytokines inhibited MCP-1 expression. In contrast, gamma interferon inhibited LAM-induced PTX3 expression. Thus, in addition to IL-1, TNF, and lipopolysaccharide, mycobacterial cell wall components also induce expression and production of the long pentraxin PTX3. The significance of PTX3 in the immunobiology of mycobacterial infection and its relevance in relation to clinical involvement remain to be determined.
Publication
Journal: Liver Transplantation
February/9/2005
Abstract
1. Long-term prophylaxis with hepatitis B immune globulin (HBIG) significantly reduces the risk for hepatitis B virus (HBV) recurrence and increases survival. Patients with HBV cirrhosis and / or positive HBV DNA at the time of transplantation have a high risk for recurrence despite HBIG prophylaxis. 2. Pre-orthotopic liver transplantation (OLT) antiviral treatment using lamivudine (LAM) can suppress HBV replication before transplantation and may induce clinical improvement in a subset of patients. Adefovir dipivoxil (ADV) may serve as "rescue" therapy for patients with LAM resistance; its place as first-line therapy requires further evaluation. 3. Combination prophylaxis with LAM and HBIG prevents HBV recurrence in 90% to 100% of patients who undergo transplantation for hepatitis B. The optimal HBIG protocol in the "nucleoside-nucleotide analog era" remains to be determined. The place of ADV or LAM as first-line posttransplant antiviral therapy in combination with HBIG requires further studies. 4. Future research should test new protocols using lower HBIG doses given intravenously (IV) or intramuscularly (IM) alone or in combination with antiviral agents and identify patients in whom HBIG prophylaxis can be stopped safely or replaced by antiviral agents or vaccination.
Publication
Journal: Sarcoidosis Vasculitis and Diffuse Lung Diseases
March/27/2006
Abstract
Lymphangioleiomyomatosis (LAM) is a rare disease of women that is characterized by a proliferation of abnormal smooth muscle-like cells (LAM cells), which leads to cystic lung lesions, lymphatic abnormalities, and abdominal tumors (e.g., angiomyolipomas). LAM occurs sporadically or in association with tuberous sclerosis complex, an autosomal dominant syndrome characterized by hamartoma-like tumor growths. The tumor suppressor genes TSC1 and TSC2 have been implicated in the etiology of LAM, as mutations and loss of heterozygosity (LOH) in TSC2 have been detected in LAM cells. TSC1 encodes hamartin, with a postulated role in actin cytoskeleton reorganization. TSC2 encodes tuberin, a protein with roles in cell growth and proliferation, transcriptional activation, and endocytosis. LAM cells, as defined by TSC2 LOH, have been detected in blood and body fluids, and can metastasize. LAM presents insidiously with progressive breathlessness, or dramatically with recurrent pneumothorax, chylothorax, or sudden abdominal hemorrhage. CT scans show numerous thin-walled cysts throughout the lungs, abdominal angiomyolipomas, and lymphangioleiomyomas. Pulmonary function tests show reduced flow rates (FEV1) and diffusion capacity (DL(CO)). Twenty per cent of patients have positive bronchodilator responses. Exercise testing shows gas-exchange abnormalities, ventilatory limitation, and hypoxemia that may occur with near-normal lung function. Progression of disease is best assessed by measurements of DL(CO) and FEV1. In the proper clinical setting, LAM may be diagnosed by a thoraco-abdominal CT scan. Tissue biopsy with special stains (HMB-45) should be reserved for cases with atypical presentations. There is no effective treatment for LAM, but on-going therapeutic trials with rapamycin appear promising.
Publication
Journal: Leukemia
June/9/1991
Abstract
The human leukocyte adhesion molecule-1 (LAM-1, TQ1, Leu-8) is involved in the binding of human leukocytes to high endothelial venules (HEV) of peripheral lymph nodes (LN). The regulation of LAM-1 expression is unique in that leukocyte stimulation induces a rapid down-modulation of LAM-1 from the cell surface. In this study, the regulation and function of LAM-1 was studied in detail in normal lymphocytes and compared with the LAM-1 of malignant leukocytes. Modulation of LAM-1 from the cell surface occurred concomitantly with the appearance of LAM-1 in the culture medium indicating that LAM-1 is cleaved from the cell surface. Shedding of LAM-1 was decreased in the presence of protein kinase C (PKC) inhibitors. As with normal lymphocytes, cells transfected with the LAM-1 cDNA and chronic lymphocytic leukemia (CLL) cells also shed LAM-1 following phorbol myristate acetate (PMA) exposure. CLL cells expressed the same Mr LAM-1 protein as normal lymphocytes and LAM-1+ CLL cells were able to specifically bind to HEV. In addition, normal lymphocytes and LAM-1+ CLL cells were capable of binding polyphosphomonester core polysaccharide (PPME) derived from yeast cell wall, a carbohydrate which mimics an essential component of the natural ligand for LAM-1, and PPME and HEV binding was specifically blocked by a new monoclonal antibody (mAb) reactive with LAM-1. The expression of LAM-1 and other adhesion molecules was examined on cells of 118 hematopoietic malignancies. LAM-1 was most frequently expressed on CLL and follicular or diffuse small cleaved cell lymphomas, whereas most other malignancies were LAM-1-. Thus, most CLL cells and some non-Hodgkin's lymphoma cells express a functionally active LAM-1 molecule which may correlate with their capacity to migrate through the circulation and disseminate into peripheral LN.
Publication
Journal: American Journal of Transplantation
October/28/2010
Abstract
Hepatitis B virus (HBV) recurrence following orthotopic liver transplantation (OLT) is generally preventable by prophylaxis with hepatitis B immunoglobulin (HBIG) and lamivudine (LAM). However, HBV recurrence sometimes develops despite prophylaxis. This study assessed posttransplant outcomes and identified predictors of HBV recurrence. We analyzed the outcomes of 209 consecutive patients positive for hepatitis B surface antigen who underwent OLT, who received either combination prophylaxis with HBIG and LAM (89.0%) or HBIG monoprophylaxis (11.0%). The median follow-up was 36.8 months (range, 1.0-84.4). Posttransplant HBV recurrence occurred in 22 patients (10.5%), including 13 patients with drug-resistant mutations. HBV recurrence was observed in six patients after hepatocellular carcinoma (HCC) recurrence. Independent predictors of HBV recurrence were recurrent HCC (p < 0.001), LAM therapy >1.5 years (p = 0.001) and high HBV DNA titers >> or =10(5) copies/mL) at OLT (p = 0.036). In conclusion, high viremia at OLT and prolonged exposure to LAM should be further stressed as main predictors of HBV recurrence.
Authors
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
August/9/1995
Abstract
Detailed analysis of transgenic tobaccos containing a series of chimeric parB promoter/beta-glucuronidase (GUS) gene constructs allowed us to define two auxin-responsive elements (AREs) of 48 bp and 95 bp (positions -210 to -163 and -374 to -280) in the parB promoter. The two AREs responded independently to physiological concentrations of auxin. Gel retardation assays revealed binding of nuclear protein(s) to the sequence conserved between ARE I and ARE II. The auxin responsiveness of the parB promoter did not mediate the pathway through the as-1 element and transcription factor ASF-1. AREs I and II were responsive to auxin at physiological concentrations, whereas as-1 responded only to higher concentrations of auxin which may be interpreted as stress, though as-1 had been reported to be a minimal ARE [Liu, X. & Lam, E. (1994) J. Biol. Chem. 269, 668-675]. Histochemical staining of transgenic tobacco that contained a parB promoter/GUS construct demonstrated the expression of GUS activity in the shoot apex as well as in the root tips, suggesting the involvement of parB expression in meristematic activity or differentiation. The drastic change in auxin responsiveness in the transgenic plants between the 6th and 10th day after imbibition of seeds implies the development or the activation of auxin signal transduction systems during plant development.
Publication
Journal: European Respiratory Journal
October/21/1996
Abstract
Pulmonary lymphangioleiomyomatosis (LAM) is a rare disorder that affects women and can lead to serious respiratory impairment. Since Bourneville's tuberous sclerosis (TS) was first reported, the striking similarities between the two entities have led many to believe that LAM is a forme fruste of TS. This is suggested by reports that angiomyolipomas, rare tumours in themselves, are reported in 40-80% of TS patients and occur in 15-30% of LAM patients. A retrospective chart review was conducted of 14 patients that presented to our institution with a diagnosis of LAM. We sought to document the clinical manifestations, particularly the incidence and location of extrathoracic tumours, in order to further support the hypothesis that LAM is a forme fruste of TS. Twelve patients had premenopausal onset of symptoms and two postmenopausal. The diagnosis was confirmed histologically (n = 12) and/or by computed tomography (CT) scan of the thorax (n = 12). Imaging investigations revealed extrathoracic tumours in 12 of 14 patients (86%). Eight of the 14 patients (57%) had renal tumours consistent with angiomyolipomas (bilateral in five patients). Only one patient had renal symptoms (flank pain and haematuria). All had normal serum creatinine, one had a reduced creatinine clearance. Extrathoracic nonrenal tumours were discovered in the pancreas, adrenals and uterus, findings previously unreported in LAM. In summary, the incidence of extrathoracic tumours in lymphangioleiomyomatosis patients is much higher than previously reported in the literature. This increased association supports the theory that lymphangioleiomyomatosis and tuberous sclerosis represent part of a spectrum of a similar disease process.
Publication
Journal: Clinical Microbiology and Infection
August/22/2005
Abstract
In total, 226 individuals from the community were investigated for faecal carriage of Acinetobacter spp. by broth enrichment culture, followed by growth on blood agar and/or Leeds Acinetobacter Medium (LAM). Acinetobacter baumannii was isolated on both LAM and blood agar from one of 100 specimens in the UK and one of 126 specimens in The Netherlands. The predominant species were Acinetobactor johnsonii and genomic sp. 11, which were cultured from 22 and five specimens, respectively. A. baumannii did not seem to be widespread in the faecal flora of individuals in the community.
Publication
Journal: American Journal of the Medical Sciences
February/14/2001
Abstract
Lymphangioleiomyomatosis (LAM), a rare disorder of unknown cause that occurs almost exclusively in women of childbearing years, is characterized microscopically by abnormal smooth muscle proliferation in the lung, lymphatics, and mediastinal, abdominal and lower cervical lymph nodes. LAM is associated with progressive dyspnea, recurrent pneumothoraces, chylous effusions, abdominal tumors (angiomyolipoma), and chylous ascites. Because of the predilection of this disease for young women, therapies to date have mainly involved hormonal manipulation. Although the efficacy of these therapies has not been established, the clinical course is more favorable in recent studies compared with earlier reports.
Authors
Publication
Journal: International urogynecology journal and pelvic floor dysfunction
February/28/2001
Abstract
This paper reviews the role of the levator ani muscle (LAM) in evacuation, sexual performance and pelvic floor disorders. The LAM fixes the vesical neck, anorectal junction and vaginal fornices to the side wall of the pelvis by means of the suspensory sling and hiatal ligament. On contraction it shares in the mechanism of evacuation (urination, defecation). During the sexual act vaginal distension by the erect penis evokes the vaginolevator and vaginopuborectalis reflexes, with a resulting LAM contraction. The LAM also contracts upon stimulation of the clitoris or cervix uteri, an action mediated through clitoromotor and cervicomotor reflexes. LAM contraction leads to upper vagina ballooning, which acts as receptacle for semen collection, to uterine elevation and straightening and to elongation and narrowing of the vagina. These actions enhance the sexual response and prepare the uterus and vagina for the reproductive process. During ejaculation LAM contraction facilitates semen ejection. Levator subluxation and sagging leads to levator dysfunction syndrome, which may present as pudendal canal syndrome.
Authors
Publication
Journal: Journal of Tissue Engineering and Regenerative Medicine
June/4/2013
Abstract
As actual stem cell application quickly approaches tissue engineering and regenerative medicine, aspects such as cell attachment to scaffolds and biomaterials become important and are often overlooked. Here, we compare the effects of several attachment proteins on the adhesion, proliferation and stem cell identity of three promising human stem cell types: human adipose-derived stem cells (hASCs), human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs). Traditional tissue culture polystyrene plates (TCPS), Matrigel (Mat), laminin (Lam), fibronectin (FN) and poly-L-lysine (PLL) were investigated as attachment protein surfaces. For hASCs typically cultured on TCPS, laminin resulted in the greatest cell attachment and proliferation with largest cell areas, indicating favourability by cell spreading. However, mesenchymal stem cell markers indicative of hASCs were slightly more expressed on surfaces with lowest cell attachment, corresponding to increased cell roundness, a newly observed attribute in hASCs possibly indicating a more stem cell-like character. hESCs preferred Matrigel as a feeder-free culture surface. Interestingly, hiPSCs favoured laminin over Matrigel for colony expansion, shown by larger cell colony area and perimeter lengths, although cell numbers and stem cell marker expression level remained highest on Matrigel. These data provide a practical reference guide for selecting a suitable attachment method for using human induced pluripotent, embryonic or adipose stem cells in tissue engineering and regenerative medicine applications.
Publication
Journal: Advances in Pharmacological Sciences
May/12/2013
Abstract
Microbial infections of various types of wounds are a challenge to the treatment of wounds and wound healing. The study was to investigate antimicrobial and antioxidant properties of methanol leaf and stem bark extracts of Kigelia africana and methanol leaf and root extracts of Strophanthus hispidus and also to determine wound healing properties of the extracts. The antimicrobial activities of the methanol extracts were determined against two Gram-positive and two Gram-negative bacteria and a fungus using agar diffusion and micro-dilution methods. The antioxidant activity was determined using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) method. The influence of the extracts on rate of wound closure was investigated using the excision wound model and histopathological investigation of treated and untreated wound tissues performed. The MICs of leaf extract of K. africana against test organisms were 2.5-7.5 mg/mL and stem bark extract were 2.25-7.5 mg/mL. The leaf extract of S. hispidus had MIC range of 2.5-7.5 mg/mL and 2.5-10 mg/mL for root extract. The IC50 of leaf and stem bark extracts of K. africana were 56.9 and 13.7 μ g/mL, respectively and leaf and root of S. hispidus were 49.8 and 45.1 μ g/mL, respectively. K. africana extracts (7.5% w/w) showed significant (P < 0.05) wound contraction at day 7 with 72% of wound closure whiles significant (P < 0.05) wound contractions were observed on day 11 for stem bark of K. africana, leaf and root extracts of S. hispidus. Wound tissues treated with the extracts showed improved collagenation, re-epitheliazition and rapid granulation formation compared with untreated wound tissues. The extracts were found to contain alkaloids, saponins, tannins, flavonoids, carbohydrates, and sapogenetic glycosides. The HPLC finger-printing of the extracts were developed. The leaf, stem bark and root extracts of K. africana and S. hispidus exhibited antimicrobial, antioxidant, and enhanced wound healing properties and these may justify the medicinal uses of the plants for treatment of microbial infections and wounds.
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