23 research outputs found
Climate Change, Growth, and California Wildfire
Large wildfire occurrence and burned area are modeled using hydroclimate and landsurface characteristics under a range of future climate and development scenarios. The range of uncertainty for future wildfire regimes is analyzed over two emissions pathways (the Special Report on Emissions Scenarios [SRES] A2 and B1 scenarios); three global climate models (Centre National de Recherches Météorologiques CM3, Geophysical Fluid Dynamics Laboratory CM21 and National Center for Atmospheric Research PCM2); a mid‐range scenario for future population growth and development footprint; two model specifications related to the uncertainty over the speed and timing with which vegetation characteristics will shift their spatial distributions in response to trends in climate and disturbance; and two thresholds for defining the wildland‐urban interface relative to housing density. Results were assessed for three 30‐year time periods centered on 2020, 2050, and 2085, relative to a 30‐year reference period centered on 1975. Substantial increases in wildfire are anticipated for most scenarios, although the range of outcomes is large and increases with time. The increase in wildfire area burned associated with the higher emissions pathway (SRES A2) is substantial, with increases statewide ranging from 57 percent to 169 percent by 2085, and increases exceeding 100 percent in most of the forest areas of Northern California in every SRES A2 scenario by 2085. The spatial patterns associated with increased fire occurrence vary according to the speed with which the distribution of vegetation types shifts on the landscape in response to climate and disturbance, with greater increases in fire area burned tending to occur in coastal southern California, the Monterey Bay area and northern California Coast ranges in scenarios where vegetation types shift more rapidly.National Oceanic and Atmospheric Administration (NOAA) Regional
Integrated Science and Assessment Program for California, United StatesCalifornia Climate Change Center/[CEC-500-2009-046-F]//Estados UnidosUnited States Department of Agriculture (USDA) Forest Service Pacific Southwest Research Station///Estados UnidosNational Oceanic and Atmospheric Administration (NOAA) Regional Integrated Science and Assessment Program for California///Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI
Клещевой энцефалит: иммунологические показатели возможного перехода острой стадии в хроническое течение болезни
Several autoimmune diseases with chronic clinical course are characterized by detection of DNA autoantibodies in patients’ serum, while there are no such IgGs in healthy donors’ blood or in patients with acute clinical course with no evidence of chronization. Tick-borne encephalitis has not been considered this way. Several strict criteria have been applied to show that the DNase activity is an intrinsic property of IgGs from the sera of TBE patients but not from healthy donors. The relative activity of IgGs has been shown to vary extensively from patient to patient, but most of the preparations (91%) had detectable levels of the DNase activity. Polyclonal DNase IgGs were not active in the presence of EDTA or after a dialysis against EDTA, but could be activated by several externally added metal ions, with the level of activity decreasing in the order Mn2+ + Ca2+ ≥ Mn2+ + Mg2+ ≥ Mn2+ ≥ ≥ Mg2+ + Ca2+ ≥ Ca2+ ≥ Mg2+ > Ca2+, while K+ , Na+ , Ni2+, Zn2+, and Cu2+ did not stimulate DNA hydrolysis. Affinity chromatography on DNA-cellulose separated the DNase IgGs into many subfractions with various affinities for DNA and very different levels of the relative activity. Possible reasons for catalytic diversity of polyclonal human Abzs are discussed.Ряд аутоиммунных заболеваний с хроническим течением характеризуются обнаружением в крови больных ДНКаутоантител, в то время как их не содержит кровь здоровых доноров или пациентов с острым течением заболеваний, незначительным нарушением иммунного статуса, без определенной склонности к переходу в хронический процесс. Клещевой энцефалит (КЭ) не рассматривался с этих позиций. Предварительно для данной работы проведен поиск достаточно точных критериев обнаружения ДНК-активности антител иммуноглобулина (Ig) G из сыворотки крови больных КЭ и здоровых доноров. Показано, что относительная активность антител IgG значительно варьирует у пациентов, но большинство образцов (91%) имели определяемый уровень ДНКазной активности. Поликлональные ДНКазные антитела IgG не активировались в присутствии ЭДТА или после диализа с ЭДТА, но могли активироваться некоторыми добавленными ионами металлов с уровнем активности, уменьшающимся в ряду Mn2+ + Ca2+ ≥ Mn2+ + Mg2+ ≥ Mn2+ ≥ Mg2+ + Ca2+ ≥ Co2+ ≥ Mg2+ > Ca2+, в то время как K+ , Na+ , Ni2+, Zn2+ и Cu2+ не стимулировали гидролиз ДНК. Аффинная хроматография на ДНК-целлюлозе разделила ДНКазные антитела IgG на множество субфракций с различным сродством к ДНК и очень разными уровнями относительной активности. Возможные причины каталитического разнообразия поликлональных человеческих аутоантител обсуждаются
Multiple Sclerosis: Enzymatic Cross Site-Specific Hydrolysis of H1 Histone by IgGs against H1, H2A, H2B, H3, H4 Histones, and Myelin Basic Protein
Histones play a key role in chromatin remodeling and gene transcription. Further, free histones in the blood act as damage-associated molecules. Administration of histones to animals results in systemic inflammatory and toxic effects. Myelin basic protein is the principal constituent element of the myelin-proteolipid sheath of axons. Abzymes (antibodies with catalytic activities) are the original features of some autoimmune diseases. In this study, electrophoretically homogeneous IgGs against H1, H2A, H2B, H3, and H4 histones and myelin basic protein (MBP) were isolated from the blood sera of multiple sclerosis (MS) patients by several affinity chromatographies. Using MALDI mass spectrometry, the sites of H1 histone cleavage by IgGs against H1, H2A, H2B, H3, H4, and MBP were determined. It was shown that IgGs against H1 split H1 at 12 sites, while the number of cleavage sites by abzymes against other histones was lower: H2A (9), H2B (7), H3 (3), and H4 (3). The minimum rate of H1 hydrolysis was observed for antibodies against H3 and H4. A high rate of hydrolysis and the maximum number of H1 hydrolysis sites (17) were found for antibodies against MBP. Only a few sites of H1 hydrolysis by anti-H1 antibodies coincided with those for IgGs against H2A, H2B, H3, H4, and MBP. Thus, the polyreactivity of complexation and the enzymatic cross-activity of antibodies against H1, four other histones, and MBP have first been shown. Since histones act as damage molecules, abzymes against histones and MBP can play a negative role in the pathogenesis of MS and probably other different diseases as well
Comparison of DNA-Hydrolyzing Antibodies from the Cerebrospinal Fluid and Serum of Patients with Multiple Sclerosis
It was found that high-affinity anti-DNA antibodies were one of the major components of the intrathecal IgG response in multiple sclerosis (MS) patients [Williamson et al., PNAS, 2001]. Recently we have shown that IgGs from the sera of MS patients are active in the hydrolysis of DNA. Here we have shown, for the first time, that average concentration of total proteins (132-fold), total IgGs (194-fold) and anti-DNA antibodies (200-fold) in the sera is significantly higher than that in the cerebrospinal fluid (CSF) of fifteen MS patients. The relative activities of total protein from sera and CSFs varied remarkably from patient to patient. It was surprising that the specific DNase activity of the total protein of CSF reparations were 198- fold higher than the serum ones. Electrophoretically and immunologically homogeneous IgGs were obtained by sequential affinity chromatography of the CSF proteins on protein G-Sepharose and FPLC gel filtration. We present first evidence showing that IgGs from CSF not only bind but efficiently hydrolyze DNA and that average specific DNase activity of homogeneous antibodies from CSF is unpredictably ,49-fold higher than that from the sera of the same MS patients. Some possible reasons of these findings are discussed. We suggest that DNase IgGs of CSF may promote important neuropathologic mechanisms in this chronic inflammatory disorder and MS pathogenesis development.© 2014 Parkhomenko et al
HIV-Infected Patients: Cross Site-Specific Hydrolysis of H3 and H4 Histones and Myelin Basic Protein with Antibodies against These Three Proteins
Histones play important roles in chromatin functioning and gene transcription, but in the intercellular space, they are harmful since they stimulate systemic inflammatory and toxic responses. Electrophoretically homogeneous IgGs against myelin basic protein (MBP), as well as H3 and H4 histones, were isolated from sera of HIV-infected patients. In contrast to known classical proteases, these IgGs split exclusively only histones and MBP but no other control proteins. Among 13 sites of hydrolysis of H3 by IgGs against H3 and 14 sites for anti-MBP IgGs, only two sites of the hydrolysis were the same. Between seven cleavage sites of H4 with IgGs against H4 and 9 sites of this histone hydrolysis by antibodies against MBP, only three sites were the same. The sites of hydrolysis of H3 (and H4) with abzymes against these histones and against MBP were different, but several expended protein clusters containing hydrolysis sites are partially overlapped. The existence of enzymatic cross-reactivity of abzymes against H3 and H4 and MBP represents a great menace to humans since due to cell apoptosis, histones constantly occur in human blood. They can hydrolyze MBP of the myelin sheath of axons and play a negative role in the pathogenesis of HIV-infected patients
Igg-Dependent Hydrolysis of Myelin Basic Protein of Patients with Different Courses of Schizophrenia
The level hydrolysis of myelin basic protein (MBP) by IgG in patients with schizophrenia was studied depending on the clinical features and course of the disease. The patients were grouped according to type of schizophrenia and type of disease course. We found that IgGs isolated and purified from sera of schizophrenia patients’ blood hydrolyses human MBP, and the level of this hydrolysis significantly exceeds that of healthy individuals. Detection of protease activity corresponding only to intact IgGs in polyacrylamide gel fragments, together with data of gel filtration of antibodies under conditions of “acid shock” (concordance of optical density profile of IgG with profile of MBP-hydrolyzing activity) and with the absence of any other proteins and bands in gradient SDS-PAGE and in PVDF membrane provides direct evidence that the IgGs from the schizophrenia patients have MBP-hydrolyzing activity. The antibodies-specific proteolytic activity of patients with acute schizophrenia (1.026 [0.205; 3.372] mg MBP/mg IgG/h) significantly exceeds the activity of IgG in patients in remission (0.656 [0.279; 0.873] mg MBP/mg IgG/h) and in healthy individuals (0.000 [0.00; 0.367] mg MBP/mg IgG/h). When comparing the specific activity in patients with different types of disease course, we have found that patients with a continuous course of paranoid schizophrenia (1.810 [0.746; 4.101 mg MBP/mg IgG/h]) had maximal activity values. It can be assumed that the increase in the activity of MBP-hydrolyzing antibodies is due to the activation of humoral immunity in acute schizophrenia
Tick-borne encephalitis: immunological indicators of possible transformation of acute process into chronic disease
Several autoimmune diseases with chronic clinical course are characterized by detection of DNA autoantibodies in patients’ serum, while there are no such IgGs in healthy donors’ blood or in patients with acute clinical course with no evidence of chronization. Tick-borne encephalitis has not been considered this way. Several strict criteria have been applied to show that the DNase activity is an intrinsic property of IgGs from the sera of TBE patients but not from healthy donors. The relative activity of IgGs has been shown to vary extensively from patient to patient, but most of the preparations (91%) had detectable levels of the DNase activity. Polyclonal DNase IgGs were not active in the presence of EDTA or after a dialysis against EDTA, but could be activated by several externally added metal ions, with the level of activity decreasing in the order Mn2+ + Ca2+ ≥ Mn2+ + Mg2+ ≥ Mn2+ ≥ ≥ Mg2+ + Ca2+ ≥ Ca2+ ≥ Mg2+ > Ca2+, while K+ , Na+ , Ni2+, Zn2+, and Cu2+ did not stimulate DNA hydrolysis. Affinity chromatography on DNA-cellulose separated the DNase IgGs into many subfractions with various affinities for DNA and very different levels of the relative activity. Possible reasons for catalytic diversity of polyclonal human Abzs are discussed
Comparison of antibodies hydrolyzing myelin basic protein from the cerebrospinal fluid and serum of patients with multiple sclerosis
It was found that antibodies (Abs) against myelin basic protein (MBP) are the major components of the antibody response in multiple sclerosis (MS) patients. We have
recently shown that IgGs from sera of MS patients are active in the hydrolysis of MBP. However, in literature there are no available data concerning possible MBPhydrolyzing
Abs in cerebrospinal fluid (CSF) of MS patients. We have shown that the average content of IgGs in their sera is about 195-fold higher than that in their CSF. Here we have compared, for the first time, the average content of lambda- and kappa-IgGs as well as IgGs of four different subclasses (IgG1-IgG4) in CSF and sera of MS patients. The average relative content of lambda-IgGs and kappa –IgGs in the case of CSFs (8.0 and 92.0 %) and sera (12.3 and 87.7 %) are comparable, while IgG1, IgG2, IgG3, and IgG4: CSF - 40.4, 49.0, 8.2, and 2.5 % of total IgGs,
respectively and the sera - 53.6, 36.0, 5.6, and 4.8 %, decreased in different order.
Electrophoretically and immunologically homogeneous IgGs were obtained by sequential affinity chromatography of the CSF proteins on protein G-Sepharose and FPLC gel filtration. We present first evidence showing that IgGs from CSF efficiently hydrolyze MBP and that their average specific catalytic activity is unpredictably ~54-fold higher than that of Abs from sera of the same MS patients.
Some possible reasons of these findings are discussed. We suggest that anti-MBP abzymes of CSF may promote important neuropathologic mechanisms in this
chronic inflammatory disorder and in MS pathogenesis development