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1.
ESMO Open ; 9(5): 103449, 2024 May.
Article in English | MEDLINE | ID: mdl-38744098

ABSTRACT

BACKGROUND: In relapsed or refractory (RR) metastatic germ cell cancer (GCC), high-dose (HD) chemotherapy (CTX) plus autologous stem cell transplantation is considered the standard of care. Limited data exist regarding the efficacy of HD-CTX following conventionally dosed salvage regimens (CDRs). This analysis explores and contrasts the efficacy of HD-CTX as the first or subsequent salvage regimen. PATIENTS AND METHODS: Data were retrospectively collected to explore the efficacy of HD-CTX administered as the first (group A) or subsequent salvage CTX (group B) after a CDR. The primary endpoint was OS from the time of HD-CTX. Associations of survival, overall response rate (ORR), and toxicity with clinical characteristics were explored using stratified Kaplan-Meier and Cox regression models. RESULTS: Overall, 283 patients with GCC were included from 11 international centers, with 159 patients (56%) in group A and 124 patients (44%) in group B. The first salvage treatment was administered between 1998 and 2022, with a median follow-up of 27.0 [standard deviation (SD) 46.2] months for group A and 17.0 (SD 48.5) months for group B. The median OS from HD-CTX treatment initiation was not reached in group A, compared with 25 months in group B (P = 0.00027), associated with 2- and 5-year OS rates of 74% and 63% (group A) versus 53% and 37% (group B), respectively. When administered as the first salvage treatment, HD-CTX was associated with a higher ORR (79% versus 60%; P = 0.013) and lower nonhematologic grade ≥3 toxicity rate (78% versus 97%; P < 0.001). Concerning risk factor analysis for the total cohort, the International Prognostic Factors Study Group score was the only independent predictor of OS in multivariable analysis (P = 0.006). CONCLUSIONS: When administered as the initial salvage treatment or after CDR, HD-CTX exhibits curative potential for patients with RR GCC. The efficacy and safety outcomes were more favorable when HD-CTX was conducted as the first salvage treatment line.


Subject(s)
Neoplasms, Germ Cell and Embryonal , Salvage Therapy , Humans , Salvage Therapy/methods , Male , Neoplasms, Germ Cell and Embryonal/drug therapy , Retrospective Studies , Adult , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Young Adult , Treatment Outcome , Female
2.
BMC Public Health ; 21(1): 1404, 2021 07 16.
Article in English | MEDLINE | ID: mdl-34271884

ABSTRACT

BACKGROUND: BPaL, a 6 month oral regimen composed of bedaquiline, pretomanid, and linezolid for treating extensively drug-resistant tuberculosis (XDR-TB) is a potential alternative for at least 20 months of individualized treatment regimens (ITR). The ITR has low tolerability, treatment adherence, and success rates, and hence to limit patient burden, loss to follow-up and the emergence of resistance it is essential to implement new DR-TB regimens. The objective of this study was to assess the acceptability, feasibility, and likelihood of implementing BPaL in Indonesia, Kyrgyzstan, and Nigeria. METHODS: We conducted a concurrent mixed-methods study among a cross-section of health care workers, programmatic and laboratory stakeholders between May 2018 and May 2019. We conducted semi-structured interviews and focus group discussions to assess perceptions on acceptability and feasibility of implementing BPaL. We determined the proportions of a recoded 3-point Likert scale (acceptable; neutral; unacceptable), as well as the overall likelihood of implementing BPaL (likely; neutral; unlikely) that participants graded per regimen, pre-defined aspect and country. We analysed the qualitative results using a deductive framework analysis. RESULTS: In total 188 stakeholders participated in this study: 63 from Kyrgyzstan, 51 from Indonesia, and 74 from Nigeria The majority were health care workers (110). Overall, 88% (146/166) of the stakeholders would likely implement BPaL once available. Overall acceptability for BPaL was high, especially patient friendliness was often rated as acceptable (93%, 124/133). In contrast, patient friendliness of the ITR was rated as acceptable by 45%. Stakeholders appreciated that BPaL would reduce workload and financial burden on the health care system. However, several stakeholders expressed concerns regarding BPaL safety (monitoring), long-term efficacy, and national regulatory requirements regarding introduction of the regimen. Stakeholders stressed the importance of addressing current health systems constraints as well, especially in treatment and safety monitoring systems. CONCLUSIONS: Acceptability and feasibility of the BPaL regimen is high among TB stakeholders in Indonesia, Kyrgyzstan, and Nigeria. The majority is willing to start using BPaL as the standard of care for eligible patients despite country-specific health system constraints.


Subject(s)
Extensively Drug-Resistant Tuberculosis , Tuberculosis, Multidrug-Resistant , Antitubercular Agents/therapeutic use , Feasibility Studies , Humans , Indonesia , Kyrgyzstan , Nigeria , Tuberculosis, Multidrug-Resistant/drug therapy
4.
AIDS Behav ; 22(2): 606-615, 2018 02.
Article in English | MEDLINE | ID: mdl-28439755

ABSTRACT

Human immunodeficiency virus (HIV) self-testing presents an empowering alternative to facility-based testing for reaching undiagnosed HIV infected individuals, but is not currently available in Canada. We surveyed stakeholders (clinical providers, public health professionals, researchers) engaged in HIV testing initiatives nationwide to identify the concerns, opportunities and challenges to implementing HIV self-testing in Canada. An online cross-sectional survey was disseminated by the Canadian Institutes of Health Research Centre for REACH 2.0 National HIV & sexually transmitted and blood borne infections working group to stakeholders nationwide, with a target sample size of 200. Quantitative and qualitative data were analyzed using a mixed-methods, respondent-informed approach, to inform subsequent HIV self-testing in a country where self-testing is not yet accessible. A total of 183 responses were received. A majority (70.7%) (128/181) felt that self-testing was a necessary investment to reach the undiagnosed. 64.6% (117/181) felt that self-tests should be made available to their clients and 71.5% (128/179) of respondents agreed that self-test instructions required improvements. However, 50% (90/180) felt that self-testing will pose an economic challenge to current HIV testing models. Regardless, 21% urged for timely action and availability of HIV self-tests. Thematic analyses reflected the following concerns: (a) need for affordable self-tests, (b) need for expedited, customized, and accessible linkages to counselling, (c) concern for patients to cope with positive self-test results, (d) accuracy of self-tests to detect acute HIV and (e) liability in the context of non-disclosure. Stakeholders agreed to the provision of an option of HIV self-testing to reach the undiagnosed individuals. Concerns regarding costs and accuracy of self-tests, expedited linkages to counselling, and integration of self-test within prevailing HIV testing models, will need to be addressed before their widespread implementation.


Subject(s)
AIDS Serodiagnosis/methods , HIV Infections/diagnosis , Adult , Canada , Cross-Sectional Studies , HIV Infections/prevention & control , Humans , Male , Self Care , Surveys and Questionnaires
5.
Int J Tuberc Lung Dis ; 21(11): 87-96, 2017 11 01.
Article in English | MEDLINE | ID: mdl-29025490

ABSTRACT

Crucial to finding and treating the 4 million tuberculosis (TB) patients currently missed by national TB programmes, TB stigma is receiving well-deserved and long-delayed attention at the global level. However, the ability to measure and evaluate the success of TB stigma-reduction efforts is limited by the need for additional tools. At a 2016 TB stigma-measurement meeting held in The Hague, The Netherlands, stigma experts discussed and proposed a research agenda around four themes: 1) drivers: what are the main drivers and domains of TB stigma(s)?; 2) consequences: how consequential are TB stigmas and how are negative impacts most felt?; 3) burden: what is the global prevalence and distribution of TB stigma(s) and what explains any variation? 4): intervention: what can be done to reduce the extent and impact of TB stigma(s)? Each theme was further subdivided into research topics to be addressed to move the agenda forward. These include greater clarity on what causes TB stigmas to emerge and thrive, the difficulty of measuring the complexity of stigma, and the improbability of a universal stigma 'cure'. Nevertheless, these challenges should not hinder investments in the measurement and reduction of TB stigma. We believe it is time to focus on how, and not whether, the global community should measure and reduce TB stigma.


Subject(s)
Health Knowledge, Attitudes, Practice , Models, Theoretical , Research Design , Social Stigma , Tuberculosis, Pulmonary/psychology , Humans
6.
Int J Infect Dis ; 56: 90-100, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27810521

ABSTRACT

Tuberculosis (TB)-related stigma is an important social determinant of health. Research generally highlights how stigma can have a considerable impact on individuals and communities, including delays in seeking health care and adherence to treatment. There is scant research into the assessment of TB-related stigma in low incidence countries. This study aimed to systematically map out the research into stigma. A particular emphasis was placed on the methods employed to measure stigma, the conceptual frameworks used to understand stigma, and whether structural factors were theorized. Twenty-two studies were identified; the majority adopted a qualitative approach and aimed to assess knowledge, attitudes, and beliefs about TB. Few studies included stigma as a substantive topic. Only one study aimed to reduce stigma. A number of studies suggested that TB control measures and representations of migrants in the media reporting of TB were implicated in the production of stigma. The paucity of conceptual models and theories about how the social and structural determinants intersect with stigma was apparent. Future interventions to reduce stigma, and measurements of effectiveness, would benefit from a stronger theoretical underpinning in relation to TB stigma and the intersection between the social and structural determinants of health.


Subject(s)
Public Health , Social Determinants of Health/statistics & numerical data , Social Stigma , Tuberculosis/epidemiology , Tuberculosis/psychology , Behavioral Research , Health Knowledge, Attitudes, Practice , Humans , Incidence , Medication Adherence/psychology , Medication Adherence/statistics & numerical data , Patient Acceptance of Health Care/psychology , Patient Acceptance of Health Care/statistics & numerical data , Tuberculosis/drug therapy
7.
Bone Marrow Transplant ; 50(5): 679-84, 2015 May.
Article in English | MEDLINE | ID: mdl-25642765

ABSTRACT

Prognosis is poor for patients with biologically aggressive Non-Hodgkin lymphoma (NHL), refractory to chemotherapy or relapsed after autologous transplantation, especially when no disease control before allogeneic transplantation is achieved. In 16 patients (median age 53, median prior regimes 5) with relapsed or refractory non-remission NHL, we analysed retrospectively the efficacy of a sequential therapy comprising clofarabine re-induction followed by a reduced-intensity conditioning with fludarabine, CY and melphalan, and T-cell-replete HLA-haploidentical transplantation. High-dose CY was utilized post-transplantation. All patients engrafted. Early response (day +30) was achieved in 94%. Treatment-related grade III-IV toxicity occurred in 56%, most commonly transient elevation of transaminases (36%), while there was a low incidence of infections (19% CMV reactivation, 19% invasive fungal infection) and GVHD (GVHD: acute III-IV: 6%; mild chronic: 25%). One-year non-relapse mortality was 19%. After a median follow-up of 21 months, estimated 1- and 2-year PFS was 56 and 50%, respectively, with 11 patients (69%) still alive after 2 years. In summary, sequential therapy is feasible and effective and provides an acceptable toxicity profile in high-risk non-remission NHL. Presumably, cytotoxic reinduction with clofarabine provides enough remission time for the graft-versus lymphoma effect of HLA-haploidentical transplantation to kick in, even in lymphomas that are otherwise chemo-refractory.


Subject(s)
Adenine Nucleotides/administration & dosage , Antimetabolites, Antineoplastic/administration & dosage , Arabinonucleosides/administration & dosage , HLA Antigens , Hematopoietic Stem Cell Transplantation , Lymphoma, Non-Hodgkin , Adult , Aged , Allografts , Clofarabine , Disease-Free Survival , Female , Humans , Lymphoma, Non-Hodgkin/mortality , Lymphoma, Non-Hodgkin/therapy , Male , Middle Aged , Recurrence , Retrospective Studies , Survival Rate
8.
Bone Marrow Transplant ; 49(7): 895-901, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24820212

ABSTRACT

Haploidentical haematopoietic SCT (HSCT) using T-cell-replete grafts and post-transplant high-dose CY has found increasing acceptance. Our purpose was to evaluate the feasibility and outcome of this strategy as second HSCT incorporating donor change for acute leukaemia relapse after a first allogeneic transplantation. The courses of 20 consecutive adults (median age 37 years, 12 male) with AML (n=14), ALL (n=5) and acute bi-phenotypic leukaemia (n=1) were analysed retrospectively. Conditioning consisted of fludarabine, CY and either melphalan or TBI or tresosulfan+/-etoposide. Engraftment was achieved in 17 (85%), and a second remission was induced in 15 patients (75%) on day +30. The rate of grade II-IV acute GvHD was 35%, while chronic GvHD occurred in five patients. Most commonly observed grade III-IV toxicities were mucositis (30%), hyperbilirubinemia (20%), elevation of transaminases (20%) and creatinine (20%), while invasive fungal infection affected 30%. One-year non-relapse mortality (NRM) was 36%. At a median follow-up of 17 months, estimated 1-year OS was 45%, and 1-year relapse-free survival was 33%. This strategy was feasible and allowed for successful engraftment with a moderate rate of toxicity. Early outcome and NRM are at least comparable with results after a second HSCT from HLA-matched donors without donor change at HSCT2.


Subject(s)
Hematopoietic Stem Cell Transplantation/methods , Leukemia/therapy , Transplantation Conditioning/methods , Acute Disease , Adult , Female , Humans , Male , Middle Aged , Recurrence , Tissue Donors , Transplantation, Homologous , Young Adult
9.
J Ethnopharmacol ; 137(2): 1003-10, 2011 Sep 02.
Article in English | MEDLINE | ID: mdl-21782919

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: The medicinal plants Hunteria umbellata (HUL), Cola lepidota (CCL), Persea americana leaf (PAL), Root bark of Persea americana (RPA) and Plukenetia conophora (PCL) are used in Nigerian traditional medicine for the treatment of cancer and cancer related diseases. AIM OF THE STUDY: To scientifically evaluate the cell proliferative and apoptotic effects of the plants extracts using breast and osteocarcinoma cell lines, and also to identify the possible components via LC-MS to have a kind of chemical fingerprint. MATERIALS AND METHODS: The antiproliferative and apoptotic effects of methanolic extracts (10 µg/ml) of the five medicinal plants were subjected to in vitro evaluation using four cancer cell lines (breast-MCF-7 and BT-20; Osteocarcinoma-MG-63 and Saos-2) measured by flow cytometry. Non-tumorigenic controls MCF-12A and primary isolated osteoblasts (POB) were chosen to eliminate negative influence on healthy tissue. RESULTS: Of the five extracts RPA demonstrated a significant (P<0.05) anti-proliferative activity against estrogen receptor positive breast cancer cell lines (MCF-7). The proliferative phase was decreased by 18%, whereas, a significant increase in cell proliferation (about 27%) was observed for RPA at a concentration of 10 µg/ml. PCL, CCL, HUL and PAL did not show marked inhibition of the proliferation of cell line MCF-7. CONCLUSION: These results give suggestive evidence that the plant extracts exhibit some correlation between the claimed ethnomedicinal uses and the cell proliferative activity. RPA extract includes chemical compounds with estrogen-like activity and validates its potential use as anticancer agent, particularly against breast carcinoma; provided important information potentially helpful in drug designing and discovery. Further studies will involve the isolation of anti tumour compounds in RPA by LC-MS and detailed mechanism of anticancer activities.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Cell Proliferation/drug effects , Medicine, African Traditional , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Antineoplastic Agents, Phytogenic/isolation & purification , Apoptosis/drug effects , Bone Neoplasms/metabolism , Bone Neoplasms/pathology , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Estrogen Receptor alpha/metabolism , Estrogen Receptor beta/metabolism , Female , Flow Cytometry , Fluorescent Antibody Technique , Humans , Nigeria , Plant Extracts/isolation & purification
11.
Langenbecks Arch Surg ; 393(6): 871-6, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18297304

ABSTRACT

INTRODUCTION: Gender-specific immune responses have been found after trauma-hemorrhage. Male and female sex hormones seem to be responsible for this gender dimorphism. Alterations in sex hormone receptor expression in mice appear to contribute to the immunomodulatory effect of sex hormones after blood loss. The effect of surgical trauma on the expression of sex hormone receptors in peripheral blood mononuclear cells (PBMCs) from patients, however, remains unknown. MATERIALS AND METHODS: PBMCs were obtained from 14 patients (7 men and 7 women) undergoing major abdominal surgery preoperatively and 2 h postoperatively. The expression of the androgen and the estrogen alpha- and beta- receptors were determined by reverse transcriptase polymerase chain reaction (RT-PCR). beta-Actin was used as housekeeping gene. RESULTS: The results indicate that surgical trauma has no influence on the expression of the androgen receptor and the estrogen receptors alpha and beta in male and female patients. DISCUSSION: The data demonstrate that, in contrast to mice, no alterations in the expression of androgen and estrogen hormone receptors were evident after surgery in patients. Thus, differences in the expression of sex hormone receptors do not appear to be responsible for the gender-specific immune response after surgery.


Subject(s)
Blood Loss, Surgical/physiopathology , Estrogen Receptor alpha/genetics , Estrogen Receptor beta/genetics , RNA, Messenger/genetics , Receptors, Androgen/genetics , Adult , Aged , Colorectal Neoplasms/surgery , Female , Humans , Liver Neoplasms/secondary , Liver Neoplasms/surgery , Male , Middle Aged , Monocytes/metabolism , Pancreatic Neoplasms/surgery , Reverse Transcriptase Polymerase Chain Reaction , Shock, Hemorrhagic/genetics
12.
J Trauma ; 59(1): 162-8, 2005 Jul.
Article in English | MEDLINE | ID: mdl-16096557

ABSTRACT

BACKGROUND: Several studies indicate impaired wound healing after trauma and shock. Wound immune cell dysfunction seems to be responsible for altered wound healing after trauma-hemorrhage (T-H). In this respect, administration of the amino acid L-arginine normalized wound immune cell function under those conditions. It remains unknown, however, whether L-arginine improves impaired wound healing after T-H. METHODS: To study this, male C3H/HeN mice were subjected to a midline laparotomy (i.e., soft tissue trauma induced), and polyvinyl sponges were implanted subcutaneously at the wound site before hemorrhage (35 +/- 5 mm Hg for 90 minutes) or were subjected to sham operation. During resuscitation, mice received 300 mg/kg body weight L-arginine or saline (vehicle). Seven days thereafter, hydroxyproline (OHP), a metabolite of collagen synthesis, was measured in the wound fluid using high-performance liquid chromatography. Collagen types I and III were determined in the wound by Western blot analysis. In addition, wound breaking strength was measured 10 days after T-H or sham operation. RESULTS: The results indicate that OHP was significantly decreased in T-H mice. L-arginine, however, restored depressed OHP in the wound fluid in the T-H animals. Similarly, L-arginine treatment prevented a significant depression of collagen I synthesis after T-H. Collagen III was not significantly affected by T-H or L-arginine. Most important, L-arginine increased maximal wound breaking strength after severe blood loss. Therefore, L-arginine improves wound healing after T-H by increasing collagen synthesis. CONCLUSION: Because L-arginine improves wound healing, the results suggest that L-arginine might represent a novel and useful adjunct to fluid resuscitation for decreasing wound complications after trauma and severe blood loss.


Subject(s)
Arginine/pharmacology , Collagen/metabolism , Hemorrhage/physiopathology , Wound Healing/drug effects , Wounds and Injuries/drug therapy , Analysis of Variance , Animals , Blotting, Western , Chromatography, High Pressure Liquid , Hydroxyproline/metabolism , Male , Mice , Mice, Inbred C3H , Random Allocation , Transforming Growth Factor beta/metabolism , Wound Healing/immunology , Wounds and Injuries/immunology
14.
Diabetologia ; 45(5): 686-92, 2002 May.
Article in English | MEDLINE | ID: mdl-12107749

ABSTRACT

AIMS/HYPOTHESIS: Proteases are used in therapy for autoimmune diseases yet the mechanism of their action remains to be determined. We studied the immunological basis of protease therapy in the context of Type I (insulin-dependent) diabetes mellitus. METHODS: We studied the effects of proteases (trypsin, papain, chymotrypsin, bromelain) on immune reactivity of a series of autoreactive T-cell clones from prediabetic subjects and patients with a recent onset of Type I diabetes and specific to the autoantigens GAD65, IA-2 and insulin-secretory granule protein. RESULTS: Cell surface expression of adhesion, co-stimulatory and homing molecules on both antigen-presenting cells and T cells was changed after protease treatment. Cytokine analyses showed a selective inhibition of proinflammatory (Th-1) but not Th-2 cytokine production. Autoreactive T-cell proliferation was inhibited at pharmacological serum concentrations, whereas non-specific proliferation to phytohaemagglutinin was not affected at these concentrations. Preincubation experiments on T cells and antigen-presenting cells separately showed that this effect was mediated by APCs, but not T-cells. CONCLUSION/INTERPRETATION: Proteases have pleiotropic immunological effects supporting an immunomodulatory potential for the intervention of chronic inflammatory diseases and Th-1 mediated oedema formation.


Subject(s)
Diabetes Mellitus, Type 1/immunology , Glutamate Decarboxylase/immunology , Isoenzymes/immunology , Membrane Proteins/genetics , Prediabetic State/immunology , Protein Tyrosine Phosphatases/genetics , T-Lymphocytes/immunology , Amino Acid Sequence , Antigens, CD/blood , Antigens, CD/genetics , Autoantigens , Autoimmunity , Clone Cells , Dendritic Cells/immunology , Endopeptidases/metabolism , Epitopes/chemistry , Epitopes/immunology , Flow Cytometry , Gene Expression Regulation/immunology , Humans , Molecular Sequence Data , Protein Tyrosine Phosphatase, Non-Receptor Type 1 , Receptor-Like Protein Tyrosine Phosphatases, Class 8
15.
J Autoimmun ; 17(2): 109-17, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11591119

ABSTRACT

Intercellular adhesion molecule (ICAM)-1 is involved in forming the immunological synapse. The contribution of ICAM-1 to immune responses is not critical because mice with a disrupted ICAM-1 gene do not have grossly abnormal immune reactivity. Here we report on the surprising finding that diabetes-prone NOD mice with a disrupted ICAM-1 gene (ICAM-1(-/-)) are completely protected from disease development. While 64% of ICAM-1(+/+) and 44% of ICAM-1(+/-) female NOD mice developed overt diabetes until 310 days old, no ICAM-1(-/-) NOD mice became hyperglycaemic. Histological examinations revealed minor infiltration around pancreatic islets of ICAM1(-/-) NOD mice. Administration of cyclophosphamide caused a progression to severe islet destruction in ICAM-1(+/+) NOD mice within 10 days. In contrast, ICAM-1(-/-) mice showed only mild insulitis. Furthermore, ICAM-1(+/+) NOD mice showed an increase of IFN-gamma, interleukin (IL)-12p40 and IL-12p35 pancreatic mRNA levels, leading to an increased ratio of IFN-gamma: IL-4 and IL-12p40: IL-12p35 expression. In contrast, ICAM-1(-/-) NOD mice did not upregulate IFN-gamma or IL-12p40 gene expression but maintained IL-4 and increased IL-12p35 gene expression. These results identify a dominant and non-redundant role of ICAM-1 in the development of autoimmune diabetes.


Subject(s)
Diabetes Mellitus, Type 1/etiology , Intercellular Adhesion Molecule-1/physiology , Animals , Crosses, Genetic , Diabetes Mellitus, Type 1/prevention & control , Female , Inflammation/immunology , Inflammation/prevention & control , Intercellular Adhesion Molecule-1/genetics , Islets of Langerhans/immunology , Islets of Langerhans/pathology , Mice , Mice, Inbred NOD , Mice, Knockout , T-Lymphocyte Subsets/immunology , Th1 Cells/immunology , Th2 Cells/immunology
17.
J Biol Chem ; 276(12): 8643-7, 2001 Mar 23.
Article in English | MEDLINE | ID: mdl-11115504

ABSTRACT

A new type of chlorophyll catabolite was isolated from extracts of de-greened primary leaves of barley (Hordeum vulgare cv. Lambic). Its constitution was elucidated by one-dimensional and two-dimensional [(1)H,(13)C]-homo- and heteronuclear NMR spectroscopic techniques and by high resolution mass spectroscopy. The isolated catabolite, a water-soluble, colorless, and nonfluorescent linear tetrapyrrole, resembles urobilinogen in which one of the propionic side chains forms a five membered isocylic ring system, indicating its origin from the chlorophylls.


Subject(s)
Chlorophyll/isolation & purification , Hordeum/metabolism , Urobilinogen/metabolism , Chlorophyll/chemistry , Chlorophyll/metabolism , Magnetic Resonance Spectroscopy , Molecular Structure
18.
Semin Cancer Biol ; 10(1): 15-23, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10888267

ABSTRACT

The involvement of histamine in cancer growth represents an old controversy and direct experimental evidence proving this hypothesis is not still available. In this paper we review the most relevant mechanisms referring to the role of histamine receptors, histidine decarboxylase and histamine release in the onset of an autocrine loop, that enables histamine to act as an autocrine growth factor. We postulate that this autocrine loop, that has been studied in an experimental mammary carcinoma model induced in rats, may be present in different human neoplasias. Therefore, the better understanding of this novel regulatory pathway that is controlled by histamine may contribute to identifying new therapeutic targets.


Subject(s)
Autocrine Communication/physiology , Growth Substances/physiology , Histamine/physiology , Animals , Histamine Release , Histidine Decarboxylase/metabolism , Mice , Neoplasms/metabolism , Rats , Receptors, Histamine/metabolism
19.
Blood ; 95(4): 1350-5, 2000 Feb 15.
Article in English | MEDLINE | ID: mdl-10666210

ABSTRACT

Mice deficient in intercellular adhesion molecule-1 (ICAM-1), lacking membranous ICAM-1, show a normal development but abnormalities of inflammatory and immune functions. Although the membrane-bound form of ICAM-1 is not detectable in the mutant strain, circulating ICAM-1 (cICAM) is present in serum from ICAM-1-deficient mice in similar amounts as in serum from wild-type mice. These findings were confirmed in vitro by flow cytometric analysis of lipopolysaccharide-stimulated spleen cells, and cICAM-enzyme-linked immunosorbent assay analysis of supernatants of cultured spleen cells. To analyze for the source of cICAM-1, spleen cell RNA was isolated and ICAM-1 RNA was amplified by reverse transcriptase-polymerase chain reaction using primers binding in the 5' and 3' untranslated regions. Different fragments were cloned and sequenced. In wild-type RNA the common 5 domain form of ICAM-1 was identified. In RNA from ICAM-1 mutant mice only 3 smaller fragments were found. Sequencing these fragments identified 3 alternatively spliced isoforms of ICAM-1, lacking 2 or 3 extracellular domains. However, in all spliced fragments the transmembrane domain was included. Therefore, we postulate that circulating forms of ICAM-1 are generated by proteolytic cleavage of membranous ICAM-1. The data indicate that the expression of membranous ICAM-1 and the appearance of circulating forms in serum are independently regulated mechanisms. (Blood. 2000;95:1350-1355)


Subject(s)
Alternative Splicing , Intercellular Adhesion Molecule-1/blood , Intercellular Adhesion Molecule-1/genetics , Lymphocytes/immunology , Shock, Septic/immunology , Animals , Cells, Cultured , Cloning, Molecular , Crosses, Genetic , Exons , Flow Cytometry , Lipopolysaccharides/toxicity , Lymphocyte Activation , Lymphocytes/drug effects , Mice , Mice, Inbred C57BL , Mice, Knockout , Protein Isoforms/blood , Protein Isoforms/deficiency , Protein Isoforms/genetics , RNA, Messenger/genetics , Reference Values , Spleen/immunology
20.
Chem Biol ; 7(2): 97-109, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10662695

ABSTRACT

BACKGROUND: Epothilones are produced by the myxobacterium Sorangium cellulosum So ce90, and, like paclitaxel (Taxol((R))), they inhibit microtubule depolymerisation and arrest the cell cycle at the G2-M phase. They are effective against P-glycoprotein-expressing multiple-drug-resistant tumor cell lines and are more water soluble than paclitaxel. The total synthesis of epothilones has been achieved, but has not provided an economically viable alternative to fermentation. We set out to clone, sequence and analyze the gene cluster responsible for the biosynthesis of the epothilones in S. cellulosum So ce90. RESULTS: A cluster of 22 open reading frames spanning 68,750 base pairs of the S. cellulosum So ce90 genome has been sequenced and found to encode nine modules of a polyketide synthase (PKS), one module of a nonribosomal peptide synthetase (NRPS), a cytochrome P450, and two putative antibiotic transport proteins. Disruptions in the genes encoding the PKS abolished epothilone production. The first PKS module and the NRPS module are proposed to co-operate in forming the thiazole heterocycle of epothilone from an acetate and a cysteine by condensation, cyclodehydration and subsequent dehydrogenation. The remaining eight PKS modules are responsible for the elaboration of the rest of the epothilone carbon skeleton. CONCLUSIONS: The overall architecture of the gene cluster responsible for epothilone biosynthesis has been determined. The availability of the cluster should facilitate the generation of designer epothilones by combinatorial biosynthesis approaches, and the heterologous expression of epothilones in surrogate microbial hosts.


Subject(s)
Epothilones , Epoxy Compounds/metabolism , Multigene Family/genetics , Myxococcales/chemistry , Myxococcales/genetics , Thiazoles/metabolism , Anti-Bacterial Agents , Antineoplastic Agents/metabolism , Bacterial Proteins/biosynthesis , Bacterial Proteins/genetics , Base Sequence , Cloning, Molecular , Gene Library , Genes, Bacterial , Macrolides , Microtubules/metabolism , Molecular Sequence Data , Multienzyme Complexes/genetics , Open Reading Frames , Peptide Synthases/genetics , Protein Biosynthesis/genetics
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