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Ayala G, Bahati M, Balan E, Chang J, Do TD, Fokeerbux NA, Hassan A, Kerboghossian J, Poonkasetwatana M, Saavedra J, Spieldenner A, Thomas RM, Tohme J, Walimba J. Partner Notification: A Community Viewpoint. J Int AIDS Soc 2019; 22 Suppl 3:e25291. [PMID: 31321916 PMCID: PMC6639673 DOI: 10.1002/jia2.25291] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 05/08/2019] [Indexed: 11/25/2022] Open
Affiliation(s)
- George Ayala
- MPact Global Action for Gay Men's Health and RightsOaklandCAUSA
| | - Mahri Bahati
- University of CaliforniaSan FranciscoCAUSA
- Innovative Response Globally to Transgender Women and HIV (IRGT)San FranciscoCAUSA
| | | | - Judy Chang
- International Network of People Who Use Drugs (INPUD)LondonUnited Kingdom
| | - Tri D Do
- University of CaliforniaSan FranciscoCAUSA
| | | | | | | | | | | | - Andrew Spieldenner
- California State UniversitySan MarcosCAUSA
- U.S. People Living with HIV CaucusSan DiegoCaliforniaUSA
| | - Ruth M Thomas
- Global Network of Sex Work ProjectsEdinburghScotland
| | - Johnny Tohme
- MPact Global Action for Gay Men's Health and RightsOaklandCAUSA
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Thomas RM, De Sanctis T, Gazzola V, Keysers C. Where and how our brain represents the temporal structure of observed action. Neuroimage 2018; 183:677-697. [PMID: 30165253 PMCID: PMC6215330 DOI: 10.1016/j.neuroimage.2018.08.056] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 08/20/2018] [Accepted: 08/23/2018] [Indexed: 12/30/2022] Open
Abstract
Reacting faster to the behaviour of others provides evolutionary advantages. Reacting to unpredictable events takes hundreds of milliseconds. Understanding where and how the brain represents what actions are likely to follow one another is, therefore, important. Everyday actions occur in predictable sequences, yet neuroscientists focus on how brains respond to unexpected, individual motor acts. Using fMRI, we show the brain encodes sequence-related information in the motor system. Using EEG, we show visual responses are faster and smaller for predictable sequences. We hope this paradigm encourages the field to shift its focus from single acts to motor sequences. It sheds light on how we adapt to the actions of others and suggests that the motor system may implement perceptual predictive coding.
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Affiliation(s)
- R M Thomas
- The Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, the Netherlands; Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - T De Sanctis
- The Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, the Netherlands; PharmAccess Foundation, Amsterdam, Netherlands
| | - V Gazzola
- The Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, the Netherlands; Brain & Cognition, Department of Psychology, University of Amsterdam, Amsterdam, the Netherlands.
| | - C Keysers
- The Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, the Netherlands; Brain & Cognition, Department of Psychology, University of Amsterdam, Amsterdam, the Netherlands.
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Heckert J, Thomas RM, Parkman HP. Gastric neuromuscular histology in patients with refractory gastroparesis: Relationships to etiology, gastric emptying, and response to gastric electric stimulation. Neurogastroenterol Motil 2017; 29. [PMID: 28374487 DOI: 10.1111/nmo.13068] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/21/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND The aims of this study were to describe the histology in gastroparesis, specifically to relate histopathology to etiology of gastroparesis (idiopathic and diabetic gastroparesis), gastric emptying, and clinical response to gastric electric stimulation. METHODS Full thickness gastric body sections obtained during insertion of gastric stimulator in gastroparetics were stained with Hematoxylin & Eosin, Masson Trichrome and immunohistochemical stains for Neuron-Specific Enolase and c-Kit. KEY RESULTS In all, 145 gastroparetics (71 diabetics, 71 idiopathic, 2 post-surgical, and 1 chronic intestinal pseudo-obstruction) had full thickness gastric body biopsies. A lymphocytic infiltrate was seen in the intermyenteric plexus in 22 diabetic and 23 idiopathic gastroparesis patients. Fibrosis was present in the inner circular layer in 13 diabetic and 15 idiopathics and in the outer longitudinal layer in 46 diabetic and 51 idiopathics. Diabetic gastroparesis had less ganglion cells (3.27±1.82 vs 4.81±2.81/hpf; P<.01) and less ganglia (0.90±0.44 vs 1.10±0.50/hpf; P=.01) than idiopathic gastroparesis. Interstitial cells of Cajal (ICC) count was slightly lower in the inner circular layer in diabetic than idiopathics (2.77±1.47 vs 3.18±1.34/hpf; P=.08). Delayed gastric emptying was associated with reduced ICCs in the myenteric plexus. Global therapeutic response to gastric electric stimulation was inversely related to ganglia/hpf (R=-.22; P=.008). In diabetics, improvements in nausea, vomiting, and abdominal pain were inversely related to fibrosis. CONCLUSION AND INFERENCES Histologic assessment of full thickness gastric biopsy specimens allows correlation of histopathology to the gastroparesis disease process, its etiology, gastric emptying, and response to gastric electric stimulation treatment.
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Affiliation(s)
- J Heckert
- GI Section, Department of Pathology, Temple University School of Medicine, Philadelphia, PA, USA
| | - R M Thomas
- GI Section, Department of Pathology, Temple University School of Medicine, Philadelphia, PA, USA
| | - H P Parkman
- GI Section, Department of Pathology, Temple University School of Medicine, Philadelphia, PA, USA
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Thomas RM, Algrain HA, Ryan EJ, Popojas A, Carrigan P, Abdulrahman A, Carrillo AE. Influence of a CYP1A2 polymorphism on post-exercise heart rate variability in response to caffeine intake: a double-blind, placebo-controlled trial. Ir J Med Sci 2016; 186:285-291. [PMID: 27363424 DOI: 10.1007/s11845-016-1478-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 06/27/2016] [Indexed: 02/05/2023]
Abstract
BACKGROUND Proposed differences in caffeine metabolism due to the CYP1A2*1F polymorphism have been linked to variations in cardiovascular disease risk. AIMS We examined the influence of a CYP1A2*1F polymorphism on post-exercise heart rate variability (HRV) in response to caffeine intake. METHODS Volunteers were identified as A/A homozygotes (A/A; 4 females and 7 males; age: 25.3 ± 4.1 years; BMI: 25.9 ± 4.4 kg/m2) or C allele carriers (C allele; 3 females and 6 males; age: 25.5 ± 2.8 years; BMI: 26.6 ± 5.0 kg/m2) for participation in a repeated measures, counterbalanced, double-blind, placebo-controlled trial. Participants chewed three pieces of gum containing either caffeine (CAF) (100 mg/piece) or placebo for 5 min. Thereafter, participants cycled for 15 min at 75 % of their peak oxygen consumption. Eight HRV indices computed during 5 min at baseline (BASE), 0-5 min after exercise (POST1), and 5-10 min after exercise (POST2) were used for analysis. RESULTS No significant group differences were detected in HRV indices at BASE, POST1, or POST2 during both trials (p > 0.05). Rate of recovery (POST2-POST1) for the square root of the mean of squared differences between successive RR intervals (RMSSD) was significantly different between A/A (6.0 ± 2.5 ms) and C allele (3.6 ± 2.5 ms) groups during the CAF trial (p = 0.048). CONCLUSIONS Rate of RMSSD recovery was the only variable influenced by the CYP1A2*IF polymorphism during post-exercise in response to caffeine intake. Thus, the CYP1A2*1F polymorphism did not overtly influence the effects of caffeine intake on post-exercise HRV.
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Affiliation(s)
- R M Thomas
- Department of Biology, Chatham University, Pittsburgh, PA, USA
| | - H A Algrain
- Department of Biology, Chatham University, Pittsburgh, PA, USA
| | - E J Ryan
- Department of Exercise Science, Chatham University, Pittsburgh, PA, USA
| | - A Popojas
- Department of Biology, Chatham University, Pittsburgh, PA, USA
| | - P Carrigan
- Department of Biology, Chatham University, Pittsburgh, PA, USA
| | - A Abdulrahman
- Department of Biology, Chatham University, Pittsburgh, PA, USA
| | - A E Carrillo
- Department of Exercise Science, Chatham University, Pittsburgh, PA, USA. .,FAME Laboratory, Department of Exercise Science, University of Thessaly, Trikala, Greece.
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Grubb IR, Beckham SW, Kazatchkine M, Thomas RM, Albers ER, Cabral M, Lange J, Vella S, Kurian M, Beyrer C. Maximizing the benefits of antiretroviral therapy for key affected populations. J Int AIDS Soc 2014; 17:19320. [PMID: 25043380 PMCID: PMC4104298 DOI: 10.7448/ias.17.1.19320] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 06/30/2014] [Accepted: 07/01/2014] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Scientific research has demonstrated the clinical benefits of earlier initiation of antiretroviral treatment (ART), and that ART can markedly reduce HIV transmission to sexual partners. Ensuring universal access to ART for those who need it has long been a core principle of the HIV response, and extending the benefits of ART to key populations is critical to increasing the impact of ART and the overall effectiveness of the HIV response. However, this can only be achieved through coordinated efforts to address political, social, legal and economic barriers that key populations face in accessing HIV services. DISCUSSION Recent analyses show that HIV prevalence levels among key populations are far higher than among the general population, and they experience a range of biological and behavioural factors, and social, legal and economic barriers that increase their vulnerability to HIV and have resulted in alarmingly low ART coverage. World Health Organization 2014 consolidated guidance on HIV among key populations offers the potential for increased access to ART by key populations, following the same principles as for the general adult population. However, it should not be assumed that key populations will achieve greater access to ART unless stigma, discrimination and punitive laws, policies and practices that limit access to ART and other HIV interventions in many countries are addressed. CONCLUSIONS Rights-based approaches and investments in critical enablers, such as supportive legal and policy environments, are essential to enable wider access to ART and other HIV interventions for key populations. The primary objective of ART should always be to treat the person living with HIV; prevention is an important, additional benefit. ART should be provided only with informed consent. The preventive benefits of treatment must not be used as a pretext for failure to provide other necessary HIV programming for key populations, including comprehensive harm reduction and other prevention interventions tailored to meet the needs of key populations. An end to AIDS is only possible if we overcome the barriers of criminalization, stigma and discrimination that remain key drivers of the HIV epidemics among key populations.
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Affiliation(s)
- Ian R Grubb
- Center for Public Health and Human Rights, Johns Hopkins University, Baltimore, MD, USA
| | - Sarah W Beckham
- Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA;
| | | | - Ruth M Thomas
- Global Network of Sex Work Projects, Edinburgh, United Kingdom
| | - Eliot R Albers
- International Network of People Who Use Drugs, London, United Kingdom
| | - Mauro Cabral
- Global Action for Trans* Equality, Buenos Aires, Argentina
| | - Joep Lange
- Amsterdam Institute of Global Health and Development, Amsterdam, The Netherlands
| | - Stefano Vella
- Department of Therapeutics, HIV, Hepatitis and Global Health, Istituto Superiore di Sanità, Rome, Italy
| | | | - Chris Beyrer
- Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA
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Abstract
1. The waxes from the B. leprae, like those from tubercle bacilli, are remarkable stimulants of cells. 2. The crude wax separated from the B. leprae is a mixture of lipoids and other materials, and gives reactions that include the types of cells characteristic of the response to the tuberculo-polysaccharide, phosphatide, and wax. 3. The wax obtained from the purification of the lepra phosphatide shows similar cellular reactions but with a greater proportion of foreign body giant cells. 4. Leprosin, though a glyceride, corresponds in its physical properties to the unsaponifiable material from the tubercle bacillus. It stimulates two strains of cells, fibroblasts and monocytes. The monocytes fuse into foreign body giant cells to engulf the wax. 5. The cellular reaction to the leprosinic acid and to the crystalline alcohols is of one type only, represented by the foreign body giant cell.
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Affiliation(s)
- F R Sabin
- Laboratories of The Rockefeller Institute for Medical Research
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Sabin FR, Smithburn KC, Thomas RM. CELLULAR REACTIONS TO WAX-LIKE MATERIALS FROM ACID-FAST BACTERIA : THE UNSAPONIFIABLE FRACTION FROM THE TUBERCLE BACILLUS, STRAIN H-37. ACTA ACUST UNITED AC 2010; 62:751-69. [PMID: 19870446 PMCID: PMC2133308 DOI: 10.1084/jem.62.6.751] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
1. The unsaponifiable fractions of the Mycobacteria, though insoluble in water and extremely stable chemical compounds, are nevertheless remarkable stimulants of cells. 2. They give rise to new monocytes which surround these waxes and then fuse into giant cells which engulf them. 3. The property of acid-fastness of the waxes makes it possible to identify them within the giant cells which have phagocytized them. 4. Within the foreign body giant cells the waxes are slowly disintegrated. They appear not to damage the cells which engulf them, and hence one may infer that they take no part in caseation. 5. They have no effect on the resistance of the host.
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Affiliation(s)
- F R Sabin
- Laboratories of The Rockefeller Institute for Medical Research
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Abstract
It has been shown that in a large group of rabbits inoculated intravenously with bovine tubercle bacilli the disease which follows resolves itself into two distinct phases. The first phase manifests itself in widespread diffuse lesions which subsequently regress. The mortality rate shows a rise and fall during this period, which have been correlated with the extent of lesions and with the changes in the blood cells. The duration of this phase is approximately 80 to 90 days. Following this period the mortality rate again rises and falls, during a period when all animals show lesions of a chronic nature. In an infected group the number of fatalities in the first phase is a function of the size of the dose. When the size of the dose and other conditions are held constant, a definite basis upon which to compare the reactions of treated animals is established. Studies of the blood cells during the course of the disease show that the changes in these cells reflect the course of the lesions in the first phase when other signs are lacking and offer a valuable means of making an estimate of the state of resistance of the animal from time to time. Studies of blood counts made on rabbits before their inoculation with tuberculosis were analyzed with regard to the relative longevity of the animals. It was found that those animals whose blood cells of various sorts deviated least from the modal value for the entire group survived longer than those animals whose counts were significantly high or low.
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Affiliation(s)
- R M Thomas
- Laboratories of The Rockefeller Institute for Medical Research
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Abstract
1. The full number of erythroid cells in the blood stream of the rabbit is reached by the 3rd week of life. 2. During this period, there is a predominance of erythrogenesis in the bone marrow. 3. During the 2nd week of life the bone marrow is in a state of hyperplasia owing to the needs of the body for blood and the small space available for the marrow. 4. This hyperplasia is reduced as the growth of the bone permits the marrow to spread. The control of the growth of the bones has an important bearing on hematopoiesis. 5. During the first 3 weeks of life, the chemical factors for the multiplication of red cells as well as for the elaboration of hemoglobin become available. 6. The amount of hemoglobin does not increase as rapidly as the number of cells, so that the macrocytic anemia of the fetus becomes reduced. The proportion of hemoglobin per red cell characteristic of the adult rabbit is reached by the 3rd month. 7. Further evidence on the intravascular origin of red blood cells is given. 8. The development of all of the white blood cells, with the exception of the monocyte, goes on at a slower rate than that of the red cells. 9. The monocytes reach their full number in the blood stream in the 1st week of life; granulocytes and lymphocytes by the 5th and 6th months. 10. Each of the three strains of white cells has a different rate of development. 11. The question as to whether the stem cell or primitive cell is identical with the lymphocyte is discussed.
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Affiliation(s)
- F R Sabin
- Laboratories of The Rockefeller Institute for Medical Research
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10
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Abstract
1. Rabbits vaccinated with tubercle bacilli killed by exposure to formalin (0.4 per cent) did not show any acquired resistance to subsequent infection with bovine tubercle bacilli, while rabbits vaccinated with tubercle bacilli which had been killed by heating to 70° for 1 hour survived more than half as long again as their controls. 2. Intraperitoneal injection of either the formalin-killed vaccine or the heat-killed vaccine into guinea pigs made them skin-sensitive to tuberculoprotein MA-100. 3. The rate of absorption of the formalin-killed vaccine when introduced beneath the the skin was similar to that of the heat-killed vaccine. 4. Following the intravenous injection of heat-killed tubercle bacilli, it was found that rabbits developed a massive tubercular pneumonia. A study of the production and ultimate absorption of the cellular exudate showed that these processes were similar to those found after the injection of living bacilli. The lesions which followed the injection of heat-killed bacilli differed from the lesions found in active tuberculosis in that in any one animal they showed a striking uniformity in appearance, while in the active disease the lungs showed a great diversity in type of lesion. Studies of the blood cells during the period of injection of dead organisms showed that the changes which are characteristic of the period during which a tuberculous pneumonia develops in rabbits (30 to 40 days after inoculation) were faithfully reproduced. It is suggested that the process of regression described may be similar to that which occurs in childhood tuberculosis, in which rather extensive pulmonary lesions resolve without leaving evidence of damage to the parenchyma of the lung.
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Affiliation(s)
- R M Thomas
- Laboratories of The Rockefeller Institute for Medical Research
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Thomas RM, Duran-Reynals F. THE DEGREE OF DISPERSION OF THE BACILLUS AS A FACTOR IN INFECTION AND RESISTANCE IN EXPERIMENTAL TUBERCULOSIS. ACTA ACUST UNITED AC 2010; 62:39-64. [PMID: 19870401 PMCID: PMC2133263 DOI: 10.1084/jem.62.1.39] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
1. The skin lesions in rabbits and guinea pigs following intradermal injection of tubercle bacilli (5 strains) were greatly increased in size and severity when testicle extract was added to the inoculum. Such enhancement was followed by a more widespread and rapidly progressing disease only when virulent strains were employed. 2. Attempts to suppress the development of skin lesions resulting from the injection of either normal or tuberculous rabbits with very small quantities of tubercle bacilli mixed with testicle extract were unsuccessful. 3. The skin reactions of tuberculous guinea pigs to tuberculo-protein MA 100 were greatly increased in size and markedly reduced in intensity by the addition of testicle extract to the protein solution. The toxic effect of larger quantities of tuberculo-protein was not altered by the addition of testicle extract. 4. The dispersion of tubercle bacilli through the skin of tuberculous rabbits resulted in a marked enhancement of the Koch phenomenon but was not followed by any extension of the new infection to the viscera. Tuberculous rabbits infected on two occasions with dead tubercle bacilli suspended in testicle extract showed an increased resistance to the disease when compared with controls receiving dead bacilli suspended in saline solution. 5. The resistance conferred upon tuberculous guinea pigs by superinfection was greatly increased when the bacilli employed were dispersed through the skin with testicle extract. 6. The parenteral administration of large quantities of testicle extract to recently infected guinea pigs did not result in any increase in the extent of the visceral lesions. 7. The partial immunity conferred upon guinea pigs and rabbits by vaccination with heat-killed tubercle bacilli was increased as a result of dispersion of the vaccine through the skin with testicle extract.
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Affiliation(s)
- R M Thomas
- Laboratories of The Rockefeller Institute for Medical Research
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Abstract
OBJECTIVE The chemokine CXCL12, together with its specific receptor, CXCR4, have been shown to mediate invasiveness and metastatic behaviour in pancreatic cancer cells. The expression of CXC12/CXCR4 has not been previously examined in pancreatic intraepithelial neoplasias (PanIN), the accepted precursor lesions to pancreatic duct cancer. DESIGN In this study we sought to characterise the expression of CXCL12 and CXCR4 during the progression of PanIN using both a murine model and human tissues. RESULTS These studies reveal that both CXCL12 and CXCR4 are expressed in PanIN and that the frequency increases during PanIN progression (0% CXCR4 expression in normal mouse and human ducts vs 100% in mouse PanIN 3 and 77% in human PanIN 3). Next we demonstrate a dose-dependent increase in the proliferation of murine PanIN cells when exposed to CXCL12. Finally, we show that expression of CXCR4 in murine PanIN cells is partially dependent on mitogen-activated protein kinase (MAPK) signalling and that the effect of CXCL12 on PanIN proliferation can be abrogated by an MAPK inhibitor. CONCLUSIONS Together these results demonstrate that CXCL12/CXCR4 expression begins in the pre-invasive stages of pancreatic neoplasia, and suggest that the presence of an autocrine loop that is at least partially regulated by MAPK signalling. Further studies that define the role of CXCR4 signalling in PanIN progression will determine if CXCR4 could serve as a novel target for chemoprevention and early stage therapy in pancreatic cancer.
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Affiliation(s)
- R M Thomas
- Department of Surgery, Division of Surgical Oncology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - J Kim
- Division of Oncologic Surgery, City of Hope National Medical Center, Duarte, California, USA
| | - M P Revelo-Penafiel
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - R Angel
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - D W Dawson
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - A M Lowy
- Moores UCSD Cancer Center, Division of Surgical Oncology, La Jolla, California, USA
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Thomas RM, Saouaf SJ, Wells AD. Superantigen-induced CD4+ T cell tolerance is associated with DNA methylation and histone hypo-acetylation at cytokine gene loci. Genes Immun 2007; 8:613-8. [PMID: 17671507 DOI: 10.1038/sj.gene.6364415] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Anergy is an important mechanism of peripheral tolerance in which T cells lose the capacity to produce proinflammatory cytokines such as interleukin-2 (IL-2) and interferon-gamma (IFNgamma). To determine whether the induction of T-cell anergy in vivo is associated with epigenetic changes that oppose cytokine gene expression, we measured DNA methylation and histone acetylation at the IL2 and IFNgamma loci in CD4+ T cells from mice tolerant to a viral superantigen. Tolerant T cells exhibited more DNA methylation and less histone acetylation at the regulatory regions of the IL2 and IFNgamma genes than effector T cells, which are able to produce IL-2 and IFNgamma. These data show that T-cell anergy in this model is associated with epigenetic modifications that oppose gene expression, and suggest that these mechanisms may be important in the maintenance of tolerance.
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Affiliation(s)
- R M Thomas
- Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
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Thomas RM, Aldibbiat A, Griffin W, Cox MAA, Leech NJ, Shaw JAM. A randomized pilot study in Type 1 diabetes complicated by severe hypoglycaemia, comparing rigorous hypoglycaemia avoidance with insulin analogue therapy, CSII or education alone. Diabet Med 2007; 24:778-83. [PMID: 17535290 DOI: 10.1111/j.1464-5491.2007.02196.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To determine potential for amelioration of recurrent severe hypoglycaemia without worsening in overall control in individuals with long-standing Type 1 diabetes (T1DM). METHODS Twenty-one people with T1DM characterized by altered hypoglycaemia awareness and debilitating severe hypoglycaemia were randomized in a pilot 24-week prospective study to optimized analogue therapy (ANALOGUE; lispro/glargine); continuous subcutaneous insulin infusion therapy (CSII; lispro); or re-education with relaxation of blood glucose targets on existing conventional insulin regimen (EDUCATION). Glycaemic profiles and duration of biochemical hypoglycaemia were measured by continuous subcutaneous glucose monitoring and self-monitored blood glucose. RESULTS Further severe hypoglycaemia was prevented in five participants (71%) in each group (P = 0.06). Incidence of severe hypoglycaemia was: 0.6 (ANALOGUE), 0.9 (CSII), and 3.7 (EDUCATION) episodes per patient year. Restoration of hypoglycaemia awareness was confirmed by validated questionnaire in three (43%) ANALOGUE, four (57%) CSII and five (71%) EDUCATION patients. Glycated haemoglobin (HbA1c) was significantly improved in the ANALOGUE group between weeks 0 and 24 (8.6 +/- 1.1 vs. 7.6 +/- 0.8%; P = 0.04 for change). Non-significant improvement was seen in the CSII group (8.5 +/- 1.9 vs. 7.4 +/- 1.0%; P = 0.06). No change in HbA1c was seen in the EDUCATION group (8.5 +/- 1.1 vs. 8.3 +/- 1.0%; P = 0.54). There were no episodes of diabetic ketoacidosis or any other adverse events in any group. CONCLUSIONS In this pilot randomized trial comparing optimized ANALOGUE, CSII or EDUCATION alone in unselected individuals with recurrent severe hypoglycaemia, we show potential for restoring hypoglycaemia awareness and preventing further severe hypoglycaemia with concomitant improvement in glycaemic control in ANALOGUE and CSII groups.
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Affiliation(s)
- R M Thomas
- Newcastle Diabetes Centre, Newcastle upon Tyne, UK
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Abstract
This report discusses the issues involved in the diagnosis and management of tetanus. A 29-year-old female with a history of illicit drug use presented with progressive tetany secondary to an abscess on her forearm from subcutaneous injections. She was managed in the intensive care unit for 29 days and was discharged to the ward. The main issue in her management was control of tetanic episodes interfering with ventilation and resistant to intrathecal baclofen. Other therapeutic strategies aimed at reducing spasms included magnesium, atracurium, pancuronium, midazolam, propofol and dantrolene. We conducted searches on Medline, PUBMED and the Cochrane Database of Systematic Reviews using the following terms: tetanus, treatment, therapy, drug abuse, magnesium, baclofen and human anti-tetanus immunoglobulin (hAIG). The current strategies involved in treating tetanus are discussed.
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Affiliation(s)
- R M Thomas
- Intensive Care Unit, St James's University Hospital, Leeds, United Kingdom
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Moore FJ, Thomas RM. THE PERIODIDES OF ACID AMIDES AND THEIR ADDITION PRODUCTS WITH METALLIC SALTS. SUBSTANCES OF EXCEPTIONALLY HIGH MOLECULAR WEIGHT. J Am Chem Soc 2002. [DOI: 10.1021/ja02186a016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Moore FJ, Thomas RM. ALLANTOXANIC ACID AS AN OXIDATION PRODUCT OF URIC ACID. THIRD PAPER ON HYDROGEN PEROXIDE AS A REAGENT IN THE PURIN GROUP. J Am Chem Soc 2002. [DOI: 10.1021/ja02240a015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Thomas RM, Belsito DV, Huang C, Chen Lz LZ, Ormsby I, Simmons WJ, Cowin P, Shaw J, Doetschman T, Thorbecke GJ. Appearance of Langerhans cells in the epidermis of Tgfb1(-/-) SCID mice: paracrine and autocrine effects of transforming growth factor-beta 1 and -beta 2(1). J Invest Dermatol 2001; 117:1574-80. [PMID: 11886525 DOI: 10.1046/j.0022-202x.2001.01550.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A striking immunologic abnormality of normal and SCID Tgfb1(-/-) mice is the total absence of Langerhans cells in their epidermis. Here we show that transfer of Tgfb1(+/-) SCID bone marrow causes, within a few weeks, the appearance of Langerhans cells in the epidermis of gamma-irradiated and unirradiated Tgfb1(-/-) SCID recipients. In addition, local injection of 2 x 10(5) latent transforming growth factor-beta1 cDNA-transduced cloned CD4+ T lymphocytes causes the appearance of Langerhans cells in the ear epidermis of Tgfb1(-/-) SCID mice. This effect is enhanced by antigen-specific activation of these T cells. Injection of recombinant active transforming growth factor-beta 2 into the ear of Tgfb1(-/-) SCID mice also results in the migration of Langerhans cells into the epidermis locally, but no epidermal Langerhans cells are seen after systemic injections of transforming growth factor-beta 2. Our results suggest that transforming growth factor-beta can act in paracrine as well as autocrine fashion to induce the differentiation of precursors into Langerhans cells. Furthermore, these results indicate that the relative roles of different transforming growth factor-beta isoforms in vivo may be influenced by their local availability and/or the regulation of their conversion from latent into active form.
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Affiliation(s)
- R M Thomas
- Department of Pathology, New York University School of Medicine, New York, New York 10016, USA
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20
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Abstract
Thymidine kinase from herpes simplex virus type 1 (HSV1 TK) has been postulated to be a homodimer throughout the X-ray crystallography literature. Our study shows that HSV1 TK exists as a monomer-dimer equilibrium mixture in dilute aqueous solutions. In the presence of 150 mM NaCl, the equilibrium is characterized by a dissociation constant of 2.4 microm; this constant was determined by analytical ultracentrifugation and gel filtration experiments. Dimerization seems to be unfavorable for enzymatic activity: dimers show inferior catalytic efficiency compared to the monomers. Moreover, soluble oligomers formed by self-assembly of TK in the absence of physiological salt concentrations are even enzymatically inactive. This study investigates enzymatic and structural relevance of the TK dimer in vitro. Dissociation of the dimers into monomers is not accompanied by large overall changes in secondary or tertiary structure as shown by thermal and urea-induced unfolding studies monitored by circular dichroism and fluorescence spectroscopy. A disulfide-bridge mutant TK (V119C) was designed bearing two cysteine residues at the dimer interface in order to crosslink the two subunits covalently. Under reducing conditions, the properties of V119C and wild-type HSV1 TK (wt HSV1 TK) were identical in terms of expression yield, denaturing SDS PAGE gel electrophoresis, enzyme kinetics, CD spectra and thermal stability. Crosslinked V119C (V119Cox) was found to have an increased thermal stability with a t(m) value of 59.1(+/-0.5) degrees C which is 16 deg. C higher than for the wild type protein. This is thought to be a consequence of the conformational restriction of the dimer interface. Furthermore, enzyme kinetic studies on V119Cox revealed a K(m) for thymidine of 0.2 microm corresponding to wt HSV1 TK, but a significantly higher K(m) for ATP. The present findings raise the question whether the monomer, not the dimer, might be the active species in vivo.
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Affiliation(s)
- C Wurth
- Department of Applied BioSciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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21
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Abstract
OBJECTIVE Overlap syndromes in which persons manifest clinical, histological, or immunological features of both hepatitis C infection and autoimmune hepatitis are well described. The discordant forms of treatment for hepatitis C and autoimmune hepatitis have made medical management of these patients difficult. We report our experience in using corticosteroids as first line therapy for the hepatitis C-autoimmune hepatitis overlap syndrome. METHODS Seven patients with this overlap syndrome (diagnosis based on the presence of serum hepatitis C antibody by RIBA and serum hepatitis C RNA by polymerase chain reaction, and serum hypergammaglobulinemia, elevated ANA or ASMA titers, or histological findings consistent with autoimmune hepatitis) were treated with prednisone with or without azathioprine or cyclosporine, and followed for a median duration of 44.5 months. RESULTS Five patients (71%) showed improvement of median serum ALT level from 162 U/L to 38 U/L (p = 0.04) and median serum gamma-globulin from 2.1 g/dl to 1.4 g/dl (p = 0.04) by 6 months of therapy. The mean modified histological activity index score also decreased from 11.4 +/- 2.5 to 6.6 +/- 2.6 (p = 0.04) by at least 1 yr of therapy. One patient discontinued prednisone while taking azathioprine and experienced a rebound elevation of serum ALT that did not respond to retreatment with prednisone. Antiviral therapy was subsequently administered and resulted in biochemical and virologic response. Hepatitis C virus RNA remained detectable in all other patients. CONCLUSION Corticosteroids are beneficial as a first line therapy for some patients with the hepatitis C-autoimmune overlap syndrome, resulting in appreciable biochemical and histological response but without viral eradication.
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Affiliation(s)
- T D Schiano
- Department of Medicine, The Mount Sinai Medical Center, New York, New York 10029-6574, USA
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22
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Weber FE, Eyrich G, Grätz KW, Thomas RM, Maly FE, Sailer HF. Disulfide bridge conformers of mature BMP are inhibitors for heterotopic ossification. Biochem Biophys Res Commun 2001; 286:554-8. [PMID: 11511095 DOI: 10.1006/bbrc.2001.5408] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heterotopic ossification is a frequent complication in patients who have suffered head and neck traumas or undergone total hip replacement. Heterotopic ossification occurs when osteogenic precursor cells present at the ectopic site receive the necessary signal(s) to differentiate into osteoblasts. At the protein level, the key factors in differentiation of cells to the osteogenic lineage are BMPs. Stable BMP variants derived from the identical amino acid sequence but with different disulfide bridge configurations have been investigated and found to be capable of inhibiting ossification in vitro and in vivo in rodents. These findings provide a concept for the straightforward development of a novel class of BMP antagonists that could lead to new treatments for traumatically and genetically induced heterotopic ossification and also, possibly, for disorders in which other members of the TGF-beta superfamily are involved.
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Affiliation(s)
- F E Weber
- Klinik für Gesichts- und Kieferchirurgie, Institut für Klinische Chemie, Universitätsspital Zürich, Rämistrasse 100, Zürich, 8091, Switzerland.
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23
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Fitzpatrick TB, Killer P, Thomas RM, Jelesarov I, Amrhein N, Macheroux P. Chorismate synthase from the hyperthermophile Thermotoga maritima combines thermostability and increased rigidity with catalytic and spectral properties similar to mesophilic counterparts. J Biol Chem 2001; 276:18052-9. [PMID: 11279147 DOI: 10.1074/jbc.m100867200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Chorismate synthase, the last enzyme in the shikimate pathway, catalyzes the transformation of 5-enolpyruvylshikimate 3-phosphate to chorismate, a biochemically unique reaction in that it requires reduced FMN as a cofactor. Here we report on the cloning, expression, and characterization of the protein for the first time from an extremophilic organism Thermotoga maritima which is also one of the oldest and most slowly evolving eubacteria. The protein is monofunctional in that it does not have an intrinsic ability to reduce the FMN cofactor and thereby reflecting the nature of the ancestral enzyme. Circular dichroism studies indicate that the melting temperature of the T. maritima protein is above 92 degrees C compared with 54 degrees C for the homologous Escherichia coli protein while analytical ultracentrifugation showed that both proteins have the same quaternary structure. Interestingly, UV-visible spectral studies revealed that the dissociation constants for both oxidized FMN and 5-enolpyruvylshikimate 3-phosphate decrease 46- and 10-fold, respectively, upon heat treatment of the T. maritima protein. The heat treatment also results in the trapping of the flavin cofactor in an apolar environment, a feature which is enhanced by the presence of the substrate 5-enolpyruvylshikimate 3-phosphate. Nevertheless, stopped-flow spectrophotometric evidence suggests that the mechanism of the T. maritima protein is similar to that of the E. coli protein. In essence, the study shows that T. maritima chorismate synthase exhibits considerably higher rigidity and thermostability while it has conserved features relevant to its catalytic function.
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Affiliation(s)
- T B Fitzpatrick
- ETH-Zürich, Institut für Pflanzenwissenschaften, Universitätstrasse 2, CH-8092 Zürich, Switzerland
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24
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Sen N, Simmons WJ, Thomas RM, Erianne G, Zhang DJ, Jaeggli NS, Huang C, Xiong X, Tsiagbe VK, Ponzio NM, Thorbecke GJ. META-controlled env-initiated transcripts encoding superantigens of murine Mtv29 and Mtv7 and their possible role in B cell lymphomagenesis. J Immunol 2001; 166:5422-9. [PMID: 11313379 DOI: 10.4049/jimmunol.166.9.5422] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Spontaneous germinal center (GC)-derived B cell lymphomas of SJL mice (RCS) transcribe a 1.8-kb Mtv-29 mRNA under control of the META-env promoter. The encoded vSAg29 stimulates syngeneic Vbeta16(+) CD4(+) T cells, thereby acquiring T cell help necessary for RCS growth. Other strains of B cell lymphoma-prone mice include Mtv29(+) C57L and MA/MyJ, and the Mtv29(-) Mtv7(+)-recombinant inbred strain, SW x J-1. The lymphomas of these mice produce similar mouse mtv-vSAg-encoding mRNA, as characterized by Northern blotting, PCR, and RNase protection. A 1.8-kb mRNA in C57L/J and MA/MyJ lymphomas hybridized with an Mtv29-specific oligonucleotide, whereas SW x J-1 lymphomas produced 1.8-kb transcripts hybridizing with an Mtv7-specific oligonucleotide. Similar META-env-initiated transcripts were absent from LPS-activated B cells from any strain examined but were detected in Peyer's patch RNA from SJL mice. Like typical SJL-derived RCS, all these lymphomas stimulated syngeneic CD4(+) T cells and Vbeta16(+) T hybridoma cells. Immunohistochemical staining of primary tumors showed the presence of peanut agglutinin binding (PNA(+)) highly mitotic lymphoblasts, suggesting their GC derivation. The findings indicate that this novel mRNA for Mtv29 is present in B cell lymphomas from several Mtv29(+) mouse strains. Additionally, this is the first description of the ability of Mtv7 to produce transcripts that are controlled and spliced identically to those of Mtv29 and that are expressed in SW x J-1, I-A(s+), lymphomas that also stimulate Vbeta16(+) T cells. Our results suggest an important role for mouse mtv-vSAgs and Vbeta16 T cell stimulation in the development of GC-derived murine B cell lymphomas.
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MESH Headings
- Animals
- Antigens, Viral
- B-Lymphocytes/immunology
- B-Lymphocytes/metabolism
- B-Lymphocytes/virology
- Crosses, Genetic
- Enhancer Elements, Genetic/immunology
- Female
- Genes, env/immunology
- Hybridomas
- Lymphocyte Activation/genetics
- Lymphoma, B-Cell/genetics
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/pathology
- Male
- Mammary Tumor Virus, Mouse/genetics
- Mammary Tumor Virus, Mouse/immunology
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Inbred NOD
- Promoter Regions, Genetic/immunology
- Retroviridae Infections/genetics
- Retroviridae Infections/immunology
- Retroviridae Infections/pathology
- Species Specificity
- Superantigens/genetics
- Superantigens/immunology
- T-Lymphocyte Subsets/immunology
- Transcription, Genetic/immunology
- Tumor Cells, Cultured
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
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Affiliation(s)
- N Sen
- Department of Pathology and Comprehensive Kaplan Cancer Center, New York University School of Medicine, New York, NY 10016, USA
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25
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Parkman HP, James AN, Thomas RM, Bartula LL, Ryan JP, Myers SI. Effect of indomethacin on gallbladder inflammation and contractility during acute cholecystitis. J Surg Res 2001; 96:135-42. [PMID: 11181007 DOI: 10.1006/jsre.2001.6082] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The aim of this study was to determine whether the prostaglandin synthase inhibitor indomethacin reverses the inflammation and abnormal gallbladder contractility that occur after common bile duct ligation (CBDL), a model of acute cholecystitis. METHODS Gallbladder muscle contractility was studied in vitro in normal, CBDL, and sham-operated guinea pigs. Animals were treated with saline or indomethacin in vivo. Acetylcholine (ACh) was used to directly contract the muscle and electric field stimulation (EFS) to activate intrinsic nerves. Hematoxylin and eosin-stained slides of muscle strips were scored for inflammation. RESULTS CBDL in saline-treated animals increased the inflammation score and decreased gallbladder muscle contractility to ACh and EFS. Indomethacin decreased the inflammation score and partly reversed the smooth muscle contractile response to ACh 6 and 24 h after CBDL, but not at 48 h. Indomethacin did not reverse the CBDL-induced decrease in nerve-evoked contractions. CONCLUSION Gallbladder inflammation and contractile dysfunction after CBDL are partly reversed with indomethacin at 6 and 24 h, but not at 48 h. This suggests that, early in the course of CBDL, the inflammation and contractile dysfunction are, in part, prostaglandin-mediated.
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Affiliation(s)
- H P Parkman
- Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
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26
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Abstract
We consider a simplified model of an unconfined one-dimensional detonation problem, giving a brief survey of the history of the problem and of its numerical solution. This problem with its mathematical features is typical of those solved commercially by ICI plc, and the specific values used for the chemical constants in the example are typical of those of interest. Unfortunately, not all obvious methods work well, because of the singular nature of the problem at the Chapman-Jouguet shock front. We concentrate on shooting methods for the detonation problem based on backward differentiation formula integrators, and present a new analysis which explains how these methods work. Finally, we outline some possibilities for further work, including discussing a more general detonation problem, previous solutions and potential future solution methods.
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Affiliation(s)
- J A Sturgeon
- Department of Mathematics, UMIST, Manchester, UK
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27
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Lang S, Xu J, Stuart F, Thomas RM, Vrijbloed JW, Robinson JA. Analysis of antibody A6 binding to the extracellular interferon gamma receptor alpha-chain by alanine-scanning mutagenesis and random mutagenesis with phage display. Biochemistry 2000; 39:15674-85. [PMID: 11123892 DOI: 10.1021/bi000838z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The monoclonal antibody A6 binds a conformational epitope comprising mainly the CC' surface loop on the N-terminal fibronectin type-III domain of the extracellular interferon gamma receptor (IFNgammaR). The crystal structure of an A6 Fab-IFNgammaR complex revealed an interface rich in the aromatic side chains of Trp, Tyr, and His residues. These aromatic side chains appear to interact with both polar and hydrophobic groups at the interface, a property which, in general, may be advantageous for ligand binding. To analyze these interactions in more detail, the affinities of 19 A6 alanine-scanning mutants for the IFNgammaR have been measured, using engineered A6 single chain variable region fragments, and a surface plasmon resonance biosensor. Energetically important side chains (DeltaG(mutant) - DeltaG(wt) > 2.4 kcal/mol), that form distinct hot spots in the binding interface, have been identified on both proteins. These include V(L)W92 in A6, whose benzenoid ring appears well situated for a pi-cation (or pi-amine) interaction with the side chain of receptor residue K47 and simultaneously for T-stacking onto the indole ring of W82 in the receptor. At another site, energetically important residues V(H)W52 and V(H)W53, as well as V(H)D54 and V(H)D56, surround the aliphatic side chain of the hot receptor residue K52. Taken together, the results show that side chains distributed across the interface, including many aromatic ones, make key energetic contributions to binding. In addition, the receptor CC' loop has been subjected to random mutagenesis, and receptor mutants with high affinity for A6 have been selected by phage display. Residues previously identified as important for receptor binding to A6 were conserved in the clones isolated. Some mutants, however, showed a much improved affinity for A6, due to changes at Glu55, a residue that appeared to be energetically unimportant for binding the antibody by alanine-scanning mutagenesis. An E55P receptor mutant bound A6 with a 600-fold increase in affinity (K(D) approximately 20 pM), which is one of the largest improvements in affinity from a single point mutation reported so far at any protein-protein interface.
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MESH Headings
- Alanine/genetics
- Amino Acid Sequence
- Antibodies, Monoclonal/biosynthesis
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/metabolism
- Bacteriophage M13/genetics
- Bacteriophage M13/isolation & purification
- Base Sequence
- Binding Sites, Antibody/genetics
- Biosensing Techniques
- Circular Dichroism
- Cloning, Molecular
- Enzyme-Linked Immunosorbent Assay
- Extracellular Space/genetics
- Extracellular Space/metabolism
- Genomic Library
- Immunoglobulin Fragments/biosynthesis
- Immunoglobulin Fragments/chemistry
- Immunoglobulin Fragments/genetics
- Immunoglobulin Fragments/metabolism
- Molecular Sequence Data
- Mutagenesis, Insertional
- Mutagenesis, Site-Directed
- Receptors, Interferon/biosynthesis
- Receptors, Interferon/genetics
- Receptors, Interferon/immunology
- Receptors, Interferon/metabolism
- Interferon gamma Receptor
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Affiliation(s)
- S Lang
- Institute of Organic Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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28
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29
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Abstract
BACKGROUND/AIMS A recent report has highlighted the decreasing prevalence in recent years of severe intraventricular haemorrhage (IVH) in very low birthweight (VLBW) infants (<1500 g). This study attempted to identify the severity of the grade of IVH in infants with stage 3 retinopathy of prematurity (ROP), and to re-examine the association between threshold ROP and IVH. METHODS This was a retrospective study carried out over 3 years, between December 1995 and December 1998 of neonates admitted to a single neonatal intensive care unit. 28 infants with stage 3 ROP were identified from the ROP screening database. Cranial ultrasound scans were available on 24 of these infants. The scans were reviewed and the severity of IVH was graded from grade 1 to grade 4. The birth weight, sex, ethnic origin, and gestational age of the babies were recorded. The number of infants progressing to threshold disease and the treatment provided was documented. RESULTS The 24 infants had a median gestational age of 26 weeks (range 24-28 weeks) and a median birth weight of 762.5 g (range 540-1010 g). 17 infants were treated for threshold disease. 13 infants (54.2%) had IVH, of these eight (61.5%) had grade 1, two (15.4%) had grade 2, one (7.7%) had grade 3, and two (15.4%) had grade 4. 12 of the 13 infants (92.3%) with IVH had treatment with laser or cryotherapy for ROP compared with five of the remaining 11 infants (p = 0.023, Fisher's exact test). These data provide little evidence of any association between IVH and each of ethnic origin (p = 0.856), sex (p = 1), birth weight, or gestational age (p = 0.56 and p = 0.06 respectively) in infants with stage 3 ROP. CONCLUSIONS These data provide strong evidence (p = 0. 023) of an association between the presence of IVH and treatment of threshold ROP. Although the numbers in this study are small the majority of infants with stage 3 ROP had grade 1 IVH, which heralds a more favourable neurological outcome. An association between the severity of ROP and severity of IVH was not demonstrated. With improvements in neonatal care and a reduction in the prevalence of severe IVH, there appears to be a weakening of the previously reported association between severe IVH and severe ROP. However, the presence of even a minor grade of IVH may be a significant risk factor for threshold ROP once stage 3 disease is encountered.
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Affiliation(s)
- P Watts
- Strabismus and Paediatric Service, Moorfields Eye Hospital, London, UK.
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30
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Abstract
Alpha1-antichymotrypsin (A1AC) is an acute phase serine protease inhibitor, similar to alpha1-antitrypsin (A1AT) in amino acid sequence. A1AT deficiency is known to be associated with emphysema and cirrhosis; deficiency of serum A1AC has been reported to be associated with emphysema, childhood asthma, and cryptogenic cirrhosis. The hepatocyte globules associated with A1AT deficiency have been well described; A1AC deficiency also has been reported to be associated with hepatocyte globules. The aim of this study was to describe the globules of A1AC and to compare them with A1AT globules. Immunohistochemistry for A1AC and A1AT was performed on liver biopsy specimens from 15 hepatitis C virus (HCV)-positive cirrhotic patients, 14 non-HCV cirrhotic patients, and 12 other patients with chronic hepatitis C but no cirrhosis, all of whom had known serum levels of A1AC; most had known serum levels of A1AT. Five of 15 HCV-positive cirrhotic patients, 1 of 14 non-HCV cirrhotic patients, and 1 of 12 noncirrhotic chronic hepatitis C patients had A1AC globules. Two of 15 HCV-positive cirrhotic patients and 2 of 14 non-HCV cirrhotic patients had A1AT globules. Histologically, the globules of A1AC were similar to those of A1AT but were smaller and fewer; the PAS/D stain was not as helpful for A1AC as it was for A1AT; immunohistochemistry was most useful. There was not a good correlation between serum levels of A1AC and its globules in hepatocytes. A1AC globules should be included in the differential diagnosis of hepatocyte inclusions.
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Affiliation(s)
- R M Thomas
- Department of Pathology, Temple University School of Medicine, Philadelphia, PA, USA
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31
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Mittl PR, Deillon C, Sargent D, Liu N, Klauser S, Thomas RM, Gutte B, Grütter MG. The retro-GCN4 leucine zipper sequence forms a stable three-dimensional structure. Proc Natl Acad Sci U S A 2000; 97:2562-6. [PMID: 10716989 PMCID: PMC15968 DOI: 10.1073/pnas.97.6.2562] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The question of whether a protein whose natural sequence is inverted adopts a stable fold is still under debate. We have determined the 2. 1-A crystal structure of the retro-GCN4 leucine zipper. In contrast to the two-stranded helical coiled-coil GCN4 leucine zipper, the retro-leucine zipper formed a very stable, parallel four-helix bundle, which now lends itself to further structural and functional studies.
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Affiliation(s)
- P R Mittl
- Biochemisches Institut der Universität Zürich, Winterthurer Strasse 190, CH-8057 Zürich, Switzerland
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32
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Parkman HP, James AN, Bogar LJ, Bartula LL, Thomas RM, Ryan JP, Myers SI. Effect of acalculous cholecystitis on gallbladder neuromuscular transmission and contractility. J Surg Res 2000; 88:186-92. [PMID: 10644487 DOI: 10.1006/jsre.1999.5788] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Impaired smooth muscle contractility is important in the pathophysiology of acalculous cholecystitis. Common bile duct ligation (CBDL) is a model of acalculous cholecystitis, producing acute inflammatory changes and decrease in gallbladder smooth muscle contractility. The aim of this study was to determine whether there is coexistent dysfunction of neural efferent motor pathways of the gallbladder after CBDL. MATERIALS AND METHODS Gallbladder muscle contractility was studied in vitro in normal, CBDL, and sham-operated guinea pigs. Electric field stimulation (EFS; 2-16 Hz) was used to activate intrinsic nerves and exogenous acetylcholine (ACh) was used to directly stimulate the muscle. H&E-stained slides of muscle strips were scored for inflammatory changes. RESULTS After CBDL, there was a progressive increase in the inflammation score and decrease in gallbladder muscle contractility to ACh. There was also a progressive decline in EFS-induced contractility when expressed as absolute force or normalized to the maximal muscle contractile response to ACh. The nitric oxide synthase inhibitor l-NNA (10 microM) increased EFS-induced contractions by 50 +/- 25% (P = 0.05) in CBDL animals but had no effect in sham surgical controls. CONCLUSIONS CBDL with its acute gallbladder inflammation affects gallbladder contractility by two mechanisms: (1) decreased smooth muscle contractility, and (2) decreased neurally mediated contractions. The neurally mediated alterations result from dysfunction of cholinergic excitatory nerves and upregulation of nitric-oxide-mediated inhibition of smooth muscle contractility.
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Affiliation(s)
- H P Parkman
- Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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33
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Abstract
The gene encoding pyruvate phosphate dikinase (PPDK) from Giardia duodenalis was expressed using a baculovirus system. The recombinant enzyme was purified to homogeneity and its enzymological and solution structure properties characterized. The catalytic constant for the pyruvate-producing reaction was about twice as high (1560 min(-1) at 30 degrees C) as that for the reverse reaction (700 min(-1)) and the k(cat)/Km for PPi was about two orders of magnitude higher than k(cat)/Km for Pi, indicating that the pyruvate-forming reaction is much more efficient than the reverse, phosphoenolpyruvate (PEP)-forming process. The endogenous substrate levels found for PEP (0.5 mM) and pyruvate (< 80 microM) support the assumption that, under physiological conditions, the enzyme primarily performs a catabolic function. The molecular mass of the purified recombinant PPDK was analyzed by analytical ultracentrifugation and size exclusion chromatography using different assay conditions that have been reported to affect the quaternary structure of PPDKs in other organisms. Both methods clearly indicated a dimeric structure for giardial PPDK with a molecular mass of about 197 kDa (monomer mass 97.6 kDa). Several compounds, primarily structural analogs of PPi, were tested for their ability to inhibit PPDK activity. Most of the bisphosphonates examined showed either no, or only a moderate, inhibitory effect on the enzyme. Imidodiphosphate was the only competitive inhibitor with respect to PPi (Kic = 0.55 mM), whereas the bisphosphonates produced a mixed type of inhibition. The most active compound in inhibiting PPDK activity was oxalate, with a Kic value of less than 1 microM with respect to PEP.
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Affiliation(s)
- A Hiltpold
- Institute of Parasitology, University of Zürich, Switzerland
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34
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Abstract
Gallbladder motility is impaired in chronic cholelithiasis but has not been studied in acute acalculous cholecystitis. The aim of this study was to determine the effects of acute acalculous inflammation on gallbladder contractility using the common bile duct ligation (CBDL) model in guinea pigs. Three groups of guinea pigs were studied: CBDL, normal, and sham surgical controls. Gallbladder dimensions were measured, and muscle strips were used for histology and in vitro contractility studies. CBDL resulted in progressive gallbladder distension, increased serum bilirubin, and gallbladder inflammation. There was a progressive decline in muscle contractility in the CBDL group as evidenced by a decrease in the contractile response to potassium and bethanechol with the duration of CBDL. In conclusion, CBDL in the guinea pig produces acute gallbladder inflammation and decreased gallbladder muscle contractility. Direct inhibition of muscle function is indicated by impaired contractile responses to potassium depolarization and bethanechol stimulation. Although the mechanism of the decrease in contractility with CBDL is unknown, we speculate that impaired muscle contractility is secondary to inflammation and may play a role in the clinicopathology of acute acalculous cholecystitis.
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Affiliation(s)
- H P Parkman
- Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
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Thomas RM, Thomas T, Wada M, Sigal LH, Shirahata A, Thomas TJ. Facilitation of the cellular uptake of a triplex-forming oligonucleotide by novel polyamine analogues: structure-activity relationships. Biochemistry 1999; 38:13328-37. [PMID: 10529208 DOI: 10.1021/bi991004n] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The inefficient uptake of oligodeoxynucleotides, including that of TFO, through the cell membrane is a limiting factor in developing gene therapy approaches for cancer and other diseases. To develop a new strategy for oligonucleotide delivery into the nucleus, we synthesized a series of novel polyamine analogues and examined their effects on the uptake of a 37-mer [32P]-labeled TFO, targeted to the promoter region of c-myc oncogene. We used MCF-7 breast cancer cells to investigate the efficacy of polyamines on the internalization of the TFO. The uptake of TFO was enhanced by complexing it with several unsubstituted polyamine analogues at 0. 1-5 microM concentrations, with up to 6-fold increase in TFO uptake in the presence of a hexamine, 1,21-diamino-4,9,13, 18-tetraazahenicosane (H2N(CH2)(3)NH(CH2)(4)NH(CH2)(3)NH(CH2)(4)NH(CH2)(3)NH(2) or 3-4-3-4-3). TFO uptake increased with the cationicity of the polyamines; however, bis(ethyl) substitution and structural features of the methylene bridging region had significant effects on TFO uptake. The majority of labeled TFO was recovered from the nuclear fraction containing genomic DNA. Electrophoretic mobility shift assay revealed enhanced binding of TFO to a target duplex containing promoter region sequence of c-myc oncogene. Treatment of MCF-7 cells with the TFO complexed with 0.5 microM 3-4-3-4-3 suppressed c-myc mRNA level by 65%, as determined by Northern blot analysis. These data indicate a novel approach to deliver oligodeoxynucleotides to the cell nucleus, and suppress the expression of target genes, and provide new insights into the mechanism of oligonucleotide transport in living cells.
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Affiliation(s)
- R M Thomas
- Department of Medicine, The Cancer Institute of New Jersey, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick 08903, USA
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Fortune PM, Thomas RM. Sub-aponeurotic haemorrhage: a rare but life-threatening neonatal complication associated with ventouse delivery. Br J Obstet Gynaecol 1999; 106:868-70. [PMID: 10453841 DOI: 10.1111/j.1471-0528.1999.tb08412.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- P M Fortune
- Neonatal Intensive Care Unit, Northwick Park and St Mark's Hospital, Harrow, Middlesex, UK
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Hsu CW, Krevsky B, Sigman LM, Thomas RM. Rapid progression of Barrett's esophagus to metastatic esophageal carcinoma in a patient with chronic lymphocytic leukemia. J Clin Gastroenterol 1998; 27:261-4. [PMID: 9802460 DOI: 10.1097/00004836-199810000-00019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Barrett's esophagus is a common premalignant condition that predisposes to the development of adenocarcinoma of the esophagus through a process of transformation from metaplasia to dysplasia and then carcinoma. Periodic endoscopic surveillance with multiple biopsies is adopted by most physicians to detect dysplasia or early carcinoma. We report a case of an 80-year-old white man with chronic lymphocytic leukemia (CLL) who had periodic endoscopic surveillance without any evidence of dysplasia or cancer, and who died of metastatic carcinoma of the esophagus only 18 months after his last upper endoscopic examination. We suspect that the relative immunosuppressed state resulting from his CLL was the major contributor to the rapid progression of the Barrett's esophagus to cancer. Patients with CLL have higher risk of second cancers, and several cases of aggressive carcinomas have been reported in association with CLL. This is the first case report of metastatic esophageal cancer arising in Barrett's esophagus in a patient with CLL. This case suggests that we might need a more aggressive surveillance strategy for Barrett's esophagus in patients with CLL or other immunocompromised conditions.
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Affiliation(s)
- C W Hsu
- Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
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Allen AG, Thomas RM, Cadisch JT, Maskell DJ. Molecular and functional analysis of the lipopolysaccharide biosynthesis locus wlb from Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica. Mol Microbiol 1998; 29:27-38. [PMID: 9701800 DOI: 10.1046/j.1365-2958.1998.00878.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Bordetella pertussis wlb locus (wlbpe, formerly bpl) is required for the biosynthesis of a trisaccharide that, when attached to the B. pertussis lipopolysaccharide (LPS) core (band B), generates band A LPS. The equivalent loci in Bordetella bronchiseptica (wlbbr) and Bordetella parapertussis (wlbpa) were identified and cloned. The wlbbr and wlbpa loci differ from wlbpe in that they lack the insertion sequence that defines the right-hand terminus of wlbpe. Deletion of 12 kb of DNA containing the whole wlb locus (delta wlb) by allelic exchange in each of the three bordetellae had no effect on band B biosynthesis, whereas band A biosynthesis was prevented in B. pertussis and B. bronchiseptica. In B. bronchiseptica and B. parapertussis, delta wlb mutants also lacked O-antigen. Reintroduction of the wlbpe or wlbbr loci on a shuttle vector into the three delta wlb mutants restored the wild-type LPS phenotype in the B. pertussis and B. bronchiseptica mutants. In the case of B. parapertussis, which normally does not synthesize an apparent band A structure, introduction of the wlbpe or wlbbr loci now enabled the generation of band A. This suggests that the attachment point for band A trisaccharide on the LPS core is present in B. parapertussis, and further suggests that the wild-type wlbpa locus is not fully functional. Introduction of the wlbpa locus into the delta wlbpe, delta wlbbr and delta wlbpa mutants had interesting consequences. The B. bronchiseptica and B. parapertussis recipients were now able to biosynthesize O-antigen, but no band A was generated. In the B. pertussis recipient, a truncated band A was expressed consistent with a mutation in the wlbH gene, but on Western blotting the expression of a small amount of full-length band A was also seen. Evidence that the wlbHpa protein is not fully functional was provided by the failure of the wlbpa locus to fully complement a B. pertussis wlbH (delta wlbHpe) mutant. This was supported by DNA sequence data showing that a single amino acid, conserved between homologous proteins from a range of bacteria, is altered in the B. parapertussis WlbH protein.
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Affiliation(s)
- A G Allen
- Department of Clinical Veterinary Medicine, University of Cambridge, UK.
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Jelesarov I, Dürr E, Thomas RM, Bosshard HR. Salt effects on hydrophobic interaction and charge screening in the folding of a negatively charged peptide to a coiled coil (leucine zipper). Biochemistry 1998; 37:7539-50. [PMID: 9585569 DOI: 10.1021/bi972977v] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The stability of a coiled coil or leucine zipper is controlled by hydrophobic interactions and electrostatic forces between the constituent helices. We have designed a 30-residue peptide with the repeating seven-residue pattern of a coiled coil, (abcdefg)n, and with Glu in positions e and g of each heptad. The glutamate side chains prevented folding at pH values above 6 because of electrostatic repulsion across the helix dimer interface as well as within the individual helices. Protonation of the carboxylates changed the conformation from a random coil monomer to a coiled coil dimer. Folding at alkaline pH where the peptide had a net charge of -7e was promoted by the addition of salts. The nature of the charge screening cation was less important than that of the anion. The high salt concentrations (>1 M) necessary to induce folding indicated that the salt-induced folding resulted from alterations in the protein-water interaction. Folding was promoted by the kosmotropic anions sulfate and fluoride and to a lesser extent by the weak kosmotrope formate, whereas chloride and the strong chaotrope perchlorate were ineffective. Kosmotropes are excluded from the protein surface, which is preferentially hydrated, and this promotes folding by strengthening hydrophobic interactions at the coiled coil interface. Although charge neutralization also contributed to folding, it was effective only when the screening cation was partnered by a good kosmotropic anion. Folding conformed to a two-state transition from random coil monomer to coiled coil dimer and was enthalpy driven and characterized by a change in the heat capacity of unfolding of 3.9 +/- 1.2 kJ mol-1 K-1. The rate of folding was analyzed by fluorescence stopped-flow measurements. Folding occurred in a biphasic reaction in which the rapid formation of an initial dimer (kf = 2 x 10(7) M-1 s-1) was followed by an equally rapid concentration-independent rearrangement to the folded dimer (k > 100 s-1).
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Affiliation(s)
- I Jelesarov
- Biochemisches Institut der Universität Zürich, Switzerland
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Abstract
An artificial HIV enhancer-binding polypeptide has recently been dimerized by covalently linking it to the leucine zipper motif of the yeast transcriptional activator GCN4 (Liu N et al., 1997, Eur Biophys J 25:399-403). Although it seemed that the dimerization of this peptide could be best achieved by the use of the retro sequence of the leucine zipper, this approach was not implemented in the original construct. As the first step toward the synthesis of a basic region-retro leucine zipper HIV enhancer-binding fusion protein, we have now prepared the retro version of the leucine zipper (r-LZ35) and performed initial physicochemical characterization. Circular dichroism and sedimentation equilibrium studies showed that, at concentrations < 100 microM, the retro peptide was an unstructured monomer. At higher concentrations, however, the monomer was in equilibrium with a tetramer and, at 1 mM, the retro peptide was almost fully helical. N-terminal extension of the retro peptide by the tripeptide Cys-Gly-Gly resulted in a 38-residue polypeptide that could be covalently dimerized by forming a disulfide bond between two chains to give the peptide (r-LZ38)2. Even in the low micromolar concentration range peptide (r-LZ38)2 formed a stable, noncovalent, helical dimer as revealed by circular dichroism and sedimentation equilibrium in the presence and absence of guanidinium chloride. (r-LZ38)2 has been crystallized and X-ray structural analysis is under way. The disulfide-crosslinked retro-leucine zipper may lend itself to interesting protein structural studies, including protein design. The present work also highlights the structural and functional potential of retro proteins in general.
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Affiliation(s)
- N Liu
- Biochemisches Institut der Universität Zürich, Switzerland
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Abstract
Basic region helix-loop-helix (bHLH) transcription factors regulate key steps in early development by binding to regulatory DNA sites as heterodimers consisting of a tissue-specific factor and a widely expressed factor. We have examined the folding, dimerization, and DNA binding properties of the muscle-specific bHLH protein MyoD and its partner E47, to understand why these proteins preferentially associate in heterodimeric complexes with DNA. In the absence of DNA, the E47 bHLH domain forms a very stable homodimer, whereas MyoD is unfolded and monomeric. Fluorescence quenching experiments show that MyoD does not dimerize with E47 under dilute conditions in the absence of DNA. Residues in and around the loop of the E47 bHLH domain contribute to its markedly greater stability. An altered MyoD bHLH substituted with the loop segment from E47 folds in the absence of DNA, and it readily dimerizes with E47. In the presence of a specific DNA binding site, MyoD and E47 both form homodimeric complexes with DNA that have similar dissociation constants, despite the very different stabilities of these protein dimers off DNA. A 1:1 mixture of these bHLH domains forms almost exclusively heterodimeric complexes on DNA. Assembly of these bHLH-DNA complexes is apparently governed by the strength of each subunit's interaction with the DNA and not by the strength of protein-protein interactions at the dimer interface. These findings suggest that preferential association of MyoD with E47 in DNA complexes results from more favorable DNA contacts made by one or both subunits of the heterodimer in comparison with either homodimeric complex.
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Affiliation(s)
- H Wendt
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Myers BS, Martin JS, Dempsey DT, Parkman HP, Thomas RM, Ryan JP. Acute experimental colitis decreases colonic circular smooth muscle contractility in rats. Am J Physiol 1997; 273:G928-36. [PMID: 9357837 DOI: 10.1152/ajpgi.1997.273.4.g928] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Distal colitis decreases the contractility of the underlying circular smooth muscle. We examined how time after injury and lesion severity contribute to the decreased contractility and how colitis alters the calcium-handling properties of the affected muscle. Distal colitis was induced in rats by intrarectal administration of 4% acetic acid. Contractile responses to acetylcholine, increased extracellular potassium, and the G protein activator NaF were determined for circular muscle strips from sham control and colitic rats at days 1, 2, 3, 7, and 14 postenemas. Acetylcholine stimulation of tissues from day 3 colitic rats was performed in a zero calcium buffer, in the presence of nifedipine, and after depletion of intracellular stores of calcium. The colitis was graded macroscopically as mild, moderate, or severe. Regardless of agonist, maximal decrease in force developed 2 to 3 days posttreatment, followed by a gradual return to control by day 14. The inhibitory effect of colitis on contractility increased with increasing severity of inflammation. Limiting extracellular calcium influx had a greater inhibitory effect on tissues from colitic rats; intracellular calcium depletion had a greater inhibitory effect on tissues from control animals. The data suggest that both lesion severity and time after injury affect the contractile response of circular smooth muscle from the inflamed distal colon. Impaired utilization of intracellular calcium may contribute to the decreased contractility.
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Affiliation(s)
- B S Myers
- Department of Surgery, Temple University Hospital and School of Medicine, Philadelphia, Pennsylvania 19140, USA
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Veale CA, Bernstein PR, Bohnert CM, Brown FJ, Bryant C, Damewood JR, Earley R, Feeney SW, Edwards PD, Gomes B, Hulsizer JM, Kosmider BJ, Krell RD, Moore G, Salcedo TW, Shaw A, Silberstein DS, Steelman GB, Stein M, Strimpler A, Thomas RM, Vacek EP, Williams JC, Wolanin DJ, Woolson S. Orally active trifluoromethyl ketone inhibitors of human leukocyte elastase. J Med Chem 1997; 40:3173-81. [PMID: 9379436 DOI: 10.1021/jm970250z] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This paper describes the development a series of peptidyl trifluoromethyl ketone inhibitors of human leukocyte elastase which are found to have excellent pharmacological profiles. Methods have been developed that allow for the synthesis of these inhibitors in stereochemically pure form. Two of these compounds, 1k and 1l, have high levels of oral bioavailability in several species. Compound 1l has entered development as ZD8321 and is presently undergoing clinical evaluation. These compounds demonstrate that peptidyl trifluoromethyl ketone inhibitors can achieve high levels of oral activity and bioavailability, and therefore they may prove useful as therapeutic agents in the treatment of diseases in which elastase is implicated.
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Affiliation(s)
- C A Veale
- Department of Medicinal Chemistry, ZENECA Pharmaceuticals, A Business Unit of ZENECA Inc., Wilmington, Delaware 19897, USA
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Weber FE, Minestrini G, Dyer JH, Werder M, Boffelli D, Compassi S, Wehrli E, Thomas RM, Schulthess G, Hauser H. Molecular cloning of a peroxisomal Ca2+-dependent member of the mitochondrial carrier superfamily. Proc Natl Acad Sci U S A 1997; 94:8509-14. [PMID: 9238007 PMCID: PMC22978 DOI: 10.1073/pnas.94.16.8509] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/1996] [Accepted: 05/29/1997] [Indexed: 02/04/2023] Open
Abstract
A cDNA from a novel Ca2+-dependent member of the mitochondrial solute carrier superfamily was isolated from a rabbit small intestinal cDNA library. The full-length cDNA clone was 3,298 nt long and coded for a protein of 475 amino acids, with four elongation factor-hand motifs located in the N-terminal half of the molecule. The 25-kDa N-terminal polypeptide was expressed in Escherichia coli, and it was demonstrated that it bound Ca2+, undergoing a reversible and specific conformational change as a result. The conformation of the polypeptide was sensitive to Ca2+ which was bound with high affinity (Kd approximately 0.37 microM), the apparent Hill coefficient for Ca2+-induced changes being about 2.0. The deduced amino acid sequence of the C-terminal half of the molecule revealed 78% homology to Grave disease carrier protein and 67% homology to human ADP/ATP translocase; this sequence homology identified the protein as a new member of the mitochondrial transporter superfamily. Northern blot analysis revealed the presence of a single transcript of about 3,500 bases, and low expression of the transporter could be detected in the kidney but none in the liver. The main site of expression was the colon with smaller amounts found in the small intestine proximal to the ileum. Immunoelectron microscopy localized the transporter in the peroxisome, although a minor fraction was found in the mitochondria. The Ca2+ binding N-terminal half of the transporter faces the cytosol.
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Affiliation(s)
- F E Weber
- Klinik für Gesichts-und Kieferchirurgie, Universitätsspital Zürich, Frauenklinikstrasse 10, 8091 Zurich, Switzerland.
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Alexander PJ, Thomas RM. Increased risk of occurrence of neuroleptic malignant syndrome on combined treatment with lithium and neuroleptic. Indian J Psychiatry 1997; 39:251-5. [PMID: 21584083 PMCID: PMC2967123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Whether there is an increased risk of occurrence of neuroleptic malignant syndrome (NMS) on combined treatment with lithium and neuroleptic is a controversial issue. Patients seen in a general psychiatry unit of a university hospital in India were prospectively screened for NMS over a 2 year period. Diagnosis of NMS was made on operational criteria and the details of treatment at the time of occurrence of NMS were collected systematically. Eight cases of NMS were identified during the period of the study, out of which 5 (62.5%). were taking lithium and a neuroleptic together at the time of occurrence of NMS. The high prevalence of patients on lithium and neuroleptic concomitantly in our sample of NMS, and the similar findings in many of the earlier prospective studies, makes it possible to speculate whether there is an association between combined use of lithium and neuroleptic and occurrence of NMS. Findings are discussed.
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Affiliation(s)
- P J Alexander
- P. JOHN ALEXANDER, M.D., Associate Professor, Department of Psychiatry, Kasturba Medical College, Manipal 576 119, Karnataka
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Cullen JJ, Herrmann BM, Thomas RM, Fang S, Murray JA, Ledlow A, Christensen J, Conklin JL. The role of antioxidant enzymes in the control of opossum sphincter of Oddi motility. Am J Physiol 1997; 272:G1050-6. [PMID: 9176213 DOI: 10.1152/ajpgi.1997.272.5.g1050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Superoxide rapidly oxidizes nitric oxide (NO) to form peroxynitrite, thus terminating the biological activity of NO. The aims of our study were to determine if superoxide alters the motor function of the sphincter of Oddi and to localize the antioxidant enzymes in the sphincter of Oddi. Immunostaining was performed and enzyme activities were measured in the sphincter of Oddi. In physiological experiments, force-displacement transducers recorded tension in the spontaneously contracting sphincter of Oddi and after electrical field stimulation (EFS) of precontracted sphincter of Oddi. Superoxide was generated by the addition of xanthine with xanthine oxidase, superoxide radicals were scavenged by the addition of superoxide dismutase (SOD), and catalase or SOD was inhibited by diethyldithiocarbamic acid. Immunostaining demonstrated SOD and catalase immunoreactivity in ganglia situated at the serosal surface of the circular muscle. Total SOD activity was 202 +/- 12 U/mg. Generation of superoxide or inhibition of SOD increased the contractile frequency and decreased relaxation after EFS. We conclude that superoxide alters sphincter of Oddi motor function, and the presence of superoxide scavenging enzymes in enteric plexuses suggests that they may regulate sphincter of Oddi neuromuscular function by clearing endogenous superoxide.
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Affiliation(s)
- J J Cullen
- Department of Surgery, University of Iowa College of Medicine, Iowa City 52242, USA
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Abstract
BACKGROUND Carcinoid tumors of the gastrointestinal tract differ in their clinical and histopathologic features, depending on the site of origin. There are few clinicopathologic studies that specifically describe jejunoileal carcinoid tumors. METHODS One hundred sixty-seven ileal and jejunal carcinoids were retrospectively studied with emphasis on clinical, pathologic, immunohistochemical, and prognostic features. RESULTS The mean age of patients at the time of presentation was 62 +/- 12 years (range, 13-93 years). Eight patients had carcinoid syndrome (5%) and 1 had Zollinger-Ellison syndrome. Twenty-six percent of tumors were multiple, and 77% were transmurally invasive; 31% had regional lymph node metastases only, and 32% had liver or mesenteric metastases. Ninety-three percent of tumors had an insular growth pattern. Serotonin was expressed in 86% of tumors (86 of 102), chromogranin in 92%, and neuron specific enolase in 95%. Twenty percent of tumors (10 of 51) expressed prostatic acid phosphatase; 96% were argyrophil, and 98% argentaffin. Of 80 cases with follow-up data (mean follow-up, 52 +/- 5 months), 21% were dead of disease, 16% were dead of other causes, 19% were alive with disease, and 44% had no evidence of disease at last follow-up. The 5-year Kaplan-Meier survival estimate for all cases was 58%. By univariate analysis, survival was negatively correlated with distant metastases at the time of surgery (P = 0.002), mitotic rate (P = 0.01), tumor multiplicity (P = 0.01), the presence of carcinoid syndrome (P = 0.02), depth of invasion (P = 0.03), and female gender (P = 0.05); by multivariate analysis, survival was negatively associated with distant metastasis (P = 0.002), carcinoid syndrome (P = 0.01), and female gender (P = 0.03). CONCLUSIONS Jejunoileal carcinoid tumors have a relatively high rate of transmural invasion and aggressive clinical behavior. They are usually insular and largely argentaffin, with a high rate of chromogranin and serotonin positivity. These features differentiate jejunoileal carcinoids from other gastrointestinal carcinoids.
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Affiliation(s)
- A P Burke
- Department of Hepatic and Gastrointestinal Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA
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49
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Abstract
BACKGROUND Carcinoid tumors of the gastrointestinal tract differ in their clinical and histopathologic features, depending on the site of origin. There are few clinicopathologic studies that specifically describe jejunoileal carcinoid tumors. METHODS One hundred sixty-seven ileal and jejunal carcinoids were retrospectively studied with emphasis on clinical, pathologic, immunohistochemical, and prognostic features. RESULTS The mean age of patients at the time of presentation was 62 +/- 12 years (range, 13-93 years). Eight patients had carcinoid syndrome (5%) and 1 had Zollinger-Ellison syndrome. Twenty-six percent of tumors were multiple, and 77% were transmurally invasive; 31% had regional lymph node metastases only, and 32% had liver or mesenteric metastases. Ninety-three percent of tumors had an insular growth pattern. Serotonin was expressed in 86% of tumors (86 of 102), chromogranin in 92%, and neuron specific enolase in 95%. Twenty percent of tumors (10 of 51) expressed prostatic acid phosphatase; 96% were argyrophil, and 98% argentaffin. Of 80 cases with follow-up data (mean follow-up, 52 +/- 5 months), 21% were dead of disease, 16% were dead of other causes, 19% were alive with disease, and 44% had no evidence of disease at last follow-up. The 5-year Kaplan-Meier survival estimate for all cases was 58%. By univariate analysis, survival was negatively correlated with distant metastases at the time of surgery (P = 0.002), mitotic rate (P = 0.01), tumor multiplicity (P = 0.01), the presence of carcinoid syndrome (P = 0.02), depth of invasion (P = 0.03), and female gender (P = 0.05); by multivariate analysis, survival was negatively associated with distant metastasis (P = 0.002), carcinoid syndrome (P = 0.01), and female gender (P = 0.03). CONCLUSIONS Jejunoileal carcinoid tumors have a relatively high rate of transmural invasion and aggressive clinical behavior. They are usually insular and largely argentaffin, with a high rate of chromogranin and serotonin positivity. These features differentiate jejunoileal carcinoids from other gastrointestinal carcinoids.
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Affiliation(s)
- A P Burke
- Department of Hepatic and Gastrointestinal Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA
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50
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Abstract
Nitric oxide mediates esophageal peristalsis and lower esophageal sphincter (LES) relaxation. Superoxide produced with inflammation inactivates nitric oxide. Superoxide is cleared in biological systems by superoxide dismutase. We tested the hypothesis that superoxide and the superoxide scavenging system modulate LES function. Transverse strips of muscle from the opossum LES relaxed when stimulated by an electrical field. Diethyldithiocarbamite was used to inhibit copper/zinc superoxide dismutase. Xanthine and xanthine oxidase were used to generate superoxide. Xanthine with xanthine oxidase or diethyldithiocarbamite alone had no effect on the LES. However, xanthine/xanthine oxidase and diethyldithiocarbamite reduced LES relaxation 34.1% and increased its resting tone 71.2%. Superoxide dismutase did not affect LES function, but protected the tissue from the effects of diethyldithiocarbamite and xanthine/xanthine oxidase. These studies are consistent with the hypothesis that superoxide acts by inactivating nitric oxide and suggest that these antioxidant enzyme systems may play a role in the maintenance of LES function.
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Affiliation(s)
- L S Leichus
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242, USA
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