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1.
Sci Total Environ ; 946: 174111, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38908582

RESUMO

There are substantial changes in the global drylands owing to climate change and anthropogenic activities. However, this aspect is not adequately explored in the context of recent climate change and global warming. Therefore, we analyse the role of water vapour in driving precipitation and corresponding surface greenness in the global deserts using satellite measurements. Statistical techniques such as partial correlation and Randon Forest (RF) are employed to understand the relationship among the physical processes that drive water availability for desert greening. Our analysis shows that water vapour is relatively lower (<25 kg/m2) in the deserts than rest of the globe, but comparable to the polar and high-altitude regions. Among the deserts, Thar (25 kg/m2) and Sahara (15-20 kg/m2) show higher water vapour, in contrast to the American and Gobi deserts (<10 kg/m2). Trajectory analysis reveals that water vapour transport from the south Atlantic Ocean is very high (90 kg/m/s) to the Sahel region of Sahara. Similarly, water vapour comes from Arabian Sea and Indian Ocean to Thar, mainly during Indian Summer Monsoon (ISM). There is an increase in water vapour driven by a rise in moisture transport to the American, Arabian, Thar and Sub-Sahara deserts during the period 2003-2020. The rise in moisture transport and associated water vapour in the deserts enhance water availability through precipitation and soil moisture, influencing surface greenness, as illustrated by the partial correlation and RF analyses. Enhanced water vapour and water availability, together with anthropogenic activities such as agriculture and afforestation in the deserts drive greening, which is more pronounced in Thar and Sub-Sahara. This study, thus, reveals the role of atmospheric moisture in regulating the terrestrial water availability and surface greenness in the extreme arid regions on the earth.

2.
Environ Res ; 248: 118317, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38301761

RESUMO

The Third Pole (TP) is a high mountain region in the world, and is well-known for its pristine environment, but recent development activities in the region have degraded its air quality. Here, we investigate the spatial and temporal changes of the air pollutants ammonia (NH3), sulphur dioxide (SO2) and carbon monoxide (CO) in TP, and reveal their sources using satellite measurements and emission inventory. We observe a clear seasonal cycle of NH3 in TP, with high values in summer and low values in winter. The intense agriculture activities in the southern TP are the cause of high NH3 (6-8 × 1016 molec./cm2) there. Similarly, CO shows a distinct seasonal cycle with high values in spring in the southeast TP due to biomass burning. In addition, the eastern boundary of TP in the Sichuan and Qinghai provinces also show high values of CO (about 1.5 × 1018 mol/cm2), primarily owing to the industrial activities. There is no seasonal cycle found for SO2 distribution in TP, but relatively high values (8-10 mg/m2) are observed in its eastern boundary. The high-altitude pristine regions of inner TP are also getting polluted because of increased human activities in and around TP, as we estimate positive trends in CO (0.5-1.5 × 1016 mol/cm2/yr) there. In addition, positive trends are also found in NH3 (0.025 × 1016 molec./cm2/yr) during 2008-2020 in most regions of TP and SO2 (about 0.25-0.75 mg/m2/yr) in the Sichuan and Qinghai region during 2000-2020. As revealed by the emission inventory, there are high anthropogenic emissions of NH3, SO2 and CO within TP. There are emissions of pollutants from energy sectors, oil and refinery, agriculture waste burning and manure management within TP. These anthropogenic activities accelerate the ongoing development in TP, but severely erode its environment.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Humanos , Monitoramento Ambiental , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Estações do Ano , Dióxido de Enxofre
3.
Environ Res ; 238(Pt 1): 117105, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37689338

RESUMO

We analyse the long-term (1980-2020) changes in aerosols over the Third Pole (TP) and assess the changes in radiative forcing (RF) using satellite, ground-based and reanalysis data. The annual mean aerosol optical depth (AOD) varies from 0.06 to 0.24, with the highest values of around 0.2 in the north and southwest TP, which are dominated by dust from Taklimakan and Thar deserts, respectively. However, Organic Carbon (OC), Black Carbon (BC) and sulphate aerosols have significant contributions to the total AOD in the south and east TP. High amounts of dust are observed in spring and summer, but BC in winter. Trajectory analysis reveals that the air mass originated from East and South Asia carries BC and OC, whereas the air from South Asia, Central Asia and Middle East brings dust to TP. Significant positive trends in AOD is found in TP, with high values of about 0.002/yr in the eastern and southern TP. There is a gradual increase in BC and OC concentrations during 1980-2020, but the change from 2000 is phenomenal. The RF at the top of the atmosphere varies from -10 to 2 W/m2 in TP, and high positive RF of about 2 W/m2 is estimated in Pamir, Karakoram and Nyainquentanglha mountains, where the massive glacier mass exists. The RF has increased in much of TP during recent decades (2001-2020) with respect to previous decades (1981-2000), which can be due to the rise in BC and dust during the latter period. Therefore, the positive trend in BC and its associated change in RF can amplify the regional warming, and thus, the melting of glaciers or ice in TP. This is a great concern as it is directly connected to the water security of many South Asian countries.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Mudança Climática , Poeira/análise , Estações do Ano , Aerossóis/análise , Carbono/análise , Monitoramento Ambiental/métodos
4.
Environ Pollut ; 335: 122269, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37524239

RESUMO

The COVID-19 lockdown (LD) provided a unique opportunity to examine the changes in regional and global air quality. Changes in the atmospheric carbon monoxide (CO) during LD warrant a thorough analysis as CO is a major air pollutant that affects human health, ecosystem and climate. Our analysis reveals a decrease of 5-10% in the CO column during LD (April-May 2020) compared to the pre-lockdown (PreLD, March 2020) periods in regions with high anthropogenic activity, such as East China (EC), Indo-Gangetic Plain (IGP), North America, parts of Europe and Russia. However, this reduction did not occur in the regions of frequent and intense wildfires and agricultural waste burning (AWB). We find high heterogeneity in the CO column distributions, from regional to city scales during the LD period. To determine the sources of CO emissions during LD, we examined the ratios of nitrogen dioxide (NO2), sulfur dioxide (SO2) to CO for major cities in the world. This facilitated the identification of contributions from different sources; including vehicles, industries and biomass burning during LD. The comparison between CO levels during the LD and PreLD periods indicates a notable reduction in the global tropospheric CO, but no significant change in the stratosphere. It is found that CO emissions decreased during LD in the hotspot regions, but rebounded after the LD restrictions were lifted. This study, therefore, highlights the importance of policy decisions and their implementations in the global and regional scales to improve the air quality, and thus to protect public health and environment.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Humanos , Ecossistema , Material Particulado/análise , Monitoramento Ambiental , Controle de Doenças Transmissíveis , Poluição do Ar/análise , Poluentes Atmosféricos/análise
5.
Chemosphere ; 336: 139259, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37343635

RESUMO

Carbon Monoxide (CO) is not a greenhouse gas (GHG), but has the capacity to change atmospheric chemistry of other GHGs such as methane and ozone, and therefore indirectly affects Earth's radiative forcing of the GHGs and surface temperature. Here, we use the CO mixing ratio at 850 hPa from the Tropospheric Emission Spectrometer (TES) reanalysis and the Measurement of Pollution in the Troposphere (MOPITT) satellite measurements for the period 2005-2019 to examine the spatio-temporal changes in CO across the latitudes. We find a substantial decrease in global CO, about -0.21 ± 0.09 ppb/yr (-0.23 ± 0.12%/yr) with the TES data and about -0.36 ± 0.07 ppb/yr (-0.45 ± 0.08%/yr) with the MOPITT satellite measurements during the study period. The highest CO decreasing trend is observed in Eastern China (-2.7 ± 0.37 ppb/yr) followed by Myanmar (-2.142 ± 0.59 ppb/yr) and South America (-1.08 ± 0.82 ppb/yr). This negative trend in CO is primarily due to the decrease in biomass burning and stringent environmental regulations in the respective regions and countries. The sources including road transport, which account for about 33.6% of CO emissions, followed by industries (18.3%) and agricultural waste burning (8.8%), might also be responsible for the reduction in CO due to the adaptation of improved emission control technology and regulations in the past decades from 2005 to 2019. Therefore, the study provides new insights on the current trends of global CO distribution and reasons for recent reduction in global CO emissions, which would be useful for future decision-making process to control air pollution.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Ozônio , Monóxido de Carbono/análise , Poluentes Atmosféricos/análise , Poluição do Ar/prevenção & controle , Poluição do Ar/análise , Ozônio/análise , Tecnologia
6.
Appl Geogr ; 151: 102869, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36619606

RESUMO

The direct effect of pandemic induced lockdown (LD) on environment is widely explored, but its secondary impacts remain largely unexplored. Therefore, we assess the response of surface greenness and photosynthetic activity to the LD-induced improvement of air quality in India. Our analysis reveals a significant improvement in air quality marked by reduced levels of aerosols (AOD, -19.27%) and Particulate Matter (PM 2.5, -23%) during LD (2020)from pre-LD (March-September months for the period 2017-2019). The vegetation exhibits a positive response, reflected by the increase in surface greenness [Enhanced Vegetation Index (EVI, +10.4%)] and photosynthetic activity [Solar Induced Fluorescence (SiF, +11%)], during LD from pre-LD that coincides with two major agricultural seasons of India; Zaid (March-May) and Kharif (June-September). In addition, the croplands show a higher response [two-fold in EVI (14.45%) and four-fold in SiF (17.7%)] than that of forests. The prolonged growing period (phenology) and high rate of photosynthesis (intensification) led to the enhanced greening during LD owing to the reduced atmospheric pollution. This study, therefore, provides new insights into the response of vegetation to the improved air quality, which would give ideas to counter the challenges of food security in the context of climate pollution, and combat global warming by more greening.

7.
Sci Total Environ ; 838(Pt 1): 155885, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35595133

RESUMO

The increase in greenhouse gases (GHGs) due to anthropogenic activities enhances regional and global temperatures. The most abundant GHG, i.e., water vapour, has a vital positive feedback on the global warming and Earth's climate system. This study focuses on the spatial and temporal changes in water vapour in the troposphere over India and Indian Ocean as derived from the ground-based, satellite and reanalyses data, and assesses the impact on water vapour changes on the regional climate by analysing radiative effects. The analyses show that the annual mean column water vapour (CWV) is high over the northern Indian Ocean, Bay of Bengal and Peninsular India, ranging from 30 to 60 kg/m2. Most regions show significant positive trends in the annual mean CWV, about 0.1-0.2 kg/m2/yr. There is a significant positive trend in water vapour in the troposphere (except 200 hPa) over the India land regions, with the highest values at 1000 hPa (0.034 g/kg/yr). The corresponding water vapour radiative effect (WVRE) is about 20-80 W/m2, depending on seasons and regions. This study, therefore, indicates that the increase in tropospheric water vapour over India and Indian Ocean could affect the regional temperature and climate.


Assuntos
Clima , Vapor , Aquecimento Global , Oceano Índico , Estações do Ano
8.
Indian J Psychol Med ; 40(6): 528-533, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30533948

RESUMO

CONTEXT: Elder abuse has devastating consequences such as poor quality of life, psychological distress and loss of property and security. Abuse of elderly patients with depression has not been adequately researched in India. AIMS: To explore the prevalence and predictors of abuse and its relation to various sociodemographic variables in elderly patients with depression. SETTINGS AND DESIGN: A cross-sectional, observational study carried out at a tertiary care centre in Jamnagar. METHODS AND MATERIALS: In all, 100 elderly patients with depression, attending Out Patient Department of Psychiatry at Shree M. P. Shah Government Medical College and Guru Gobind Singh Hospital, Jamnagar, were selected using simple random sampling by lottery method. Actual Abuse Tool and Elder Abuse Suspicion Index were used to detect abuse. Geriatric Depression Scale was used to assess depression, and Mini Mental State Examination was used to rule out dementia. STATISTICAL ANALYSIS: Descriptive statistics, Chi-square test, and binary logistic regression were used. RESULTS: The prevalence of abuse was 24%. Among those who had experienced abuse, 50% had experienced psychological abuse, 17% had experienced neglect, 8% had experienced exploitation and 4% had experienced physical abuse. About 54% of patients with severe depression had experienced abuse. Daughters-in-law (54%) and sons (42%) were the most common perpetrators. Illiteracy and severe depression were found to be the predictors of abuse.

9.
Leukemia ; 32(4): 920-930, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29099493

RESUMO

Acalabrutinib, a highly selective Bruton's tyrosine kinase inhibitor, is associated with high overall response rates and durable remission in previously treated chronic lymphocytic leukemia (CLL); however, complete remissions were limited. To elucidate on-target and pharmacodynamic effects of acalabrutinib, we evaluated several laboratory endpoints, including proteomic changes, chemokine modulation and impact on cell migration. Pharmacological profiling of samples from acalabrutinib-treated CLL patients was used to identify strategies for achieving deeper responses, and to identify additive/synergistic combination regimens. Peripheral blood samples from 21 patients with relapsed/refractory CLL in acalabrutinib phase I (100-400 mg/day) and II (100 mg BID) clinical trials were collected prior to and on days 8 and 28 after treatment initiation and evaluated for plasma chemokines, reverse phase protein array, immunoblotting and pseudoemperipolesis. The on-target pharmacodynamic profile of acalabrutinib in CLL lymphocytes was comparable to ibrutinib in measures of acalabrutinib-mediated changes in CCL3/CCL4 chemokine production, migration assays and changes in B-cell receptor signaling pathway proteins and other downstream survival proteins. Among several CLL-targeted agents, venetoclax, when combined with acalabrutinib, showed optimal complementary activity in vitro, ex vivo and in vivo in TCL-1 adoptive transfer mouse model system of CLL. These findings support selective targeting and combinatorial potential of acalabrutinib.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/metabolismo , Adenina/análogos & derivados , Transferência Adotiva/métodos , Animais , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Benzamidas/administração & dosagem , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Movimento Celular/efeitos dos fármacos , Quimiocina CCL3/metabolismo , Quimiocina CCL4/metabolismo , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Terapia Combinada/métodos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Camundongos , Piperidinas , Inibidores de Proteínas Quinases/administração & dosagem , Proteínas Tirosina Quinases/metabolismo , Proteômica , Pirazinas/administração & dosagem , Pirazóis/administração & dosagem , Pirimidinas/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/administração & dosagem
10.
J Perinatol ; 34(5): 364-8, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24556982

RESUMO

OBJECTIVE: To investigate the impact of early skin-to-skin contact (SSC) provided for first 24 h on incidence of hypothermia in stable newborns weighing 1800 g or more during first 48 h of life. STUDY DESIGN: Stable newborns (term and late preterm: Mean gestational age 37.7 (1.35) weeks, range 34-40 weeks) having birth weight 1800 g or more (Mean weight 2605.6 (419.8) grams) were enrolled after approval from Institutional Human Research Ethics Committee (CTRI/2013/06/003790) and randomized into early SSC (intervention group) and conventional care (control group). Initial care in the delivery room for few minutes immediately after birth in both the groups was given under radiant warmer. In the intervention group, newborns were provided SSC by their mother started between 30 min and 1 h after birth for first 24 h with minimal interruption and were provided conventional care other than SSC for next 24 h of life. In the control group, newborns were kept with their mother and received conventional care other than SSC for first 48 h. Temperature and heart rate of newborns were recorded at 30 min, 1, 2, 3, 4, 5, 6, 12, 24 and at 48 h of life in both the groups. Independent Samples t-Test and relative risk were used to analyze the data. RESULT: Both groups had 50 neonates each with similar baseline characteristics. Heart rates were in normal range in both the groups. The intervention group provided an average (s.d.) of 16.98 (0.28) h of SSC over the first 24 h period. The mean temperature was significantly high in the SSC group at all time intervals starting from 1 to 48 h (P<0.05 for all). In the SSC group only two newborns (4%) had mild hypothermia (cold stress), and, of these two newborns, one had two episodes of hypothermia. All these three episodes of hypothermia occurred within first 3 h of life. In the control group 16 newborns (32%) developed hypothermia (temperature<36.5 °C) during first 48 h of life. Of them, 11 newborns had single episode, 4 newborns had two episodes and one newborn had three episodes of hypothermia. Of these 22 hypothermic episodes, 20 occurred in the first 6 h of life and 2 episodes occurred at 48 h of life. Moderate hypothermia was seen in two newborns, whereas rest had mild hypothermia. The relative risk of developing hypothermia in the control group as compared with the SSC group was 8.00 (95% CI 1.94-32.99). There was no seasonal variation in incidence of hypothermia in both the groups. CONCLUSION: Newborns in the SSC group achieved rapid thermal control as compared with the control group. Early SSC for 24 h after birth decreases incidence of hypothermia for initial 48 h of life. Early SSC needs to be aggressively promoted in term and late-preterm newborns to reduce incidence of hypothermia.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Hipotermia/epidemiologia , Recém-Nascido/fisiologia , Relações Mãe-Filho , Pele , Feminino , Humanos , Recém-Nascido Prematuro , Gravidez
11.
Indian J Microbiol ; 50(Suppl 1): 132-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22815586

RESUMO

Secretion and enzymatic characteristics of lignin peroxidases from Gloeophyllum sepiarium MTCC 1170, Cladosporium herbarum MTCC 346, Lenzites betulina MTCC 1183, Daedalea flavida MTCC 145, Hexagonia teruis MTCC 1119 and Coirolopsis floccosa MTCC 1177 ligninolytic fungal strains have been reported. Secretion of lignin peroxidase by these ligninolytic fungal strains have been found to be in the range of 0.86 to 3.0 enzyme unit per ml of the culture medium. The enzymatic characteristics like K(m), pH and temperature optima of all the lignin peroxidases of the above fungal strains have been determined using veratryl alcohol and H(2)O(2) as the variable substrates. The K(m) values using veratryl alcohol as the substrate were found to be 65.0 µM, 58.5 µM, 63.0 µM, 54.5 µM, 54.6 µM and 61.0 µM respectively. The K(m) values using H(2)O(2) as the substrate were found to be 88.0 µM, 86.0 µM, 71.0 µM, 67.0 µM, 80.0 µM and 78.0 µM respectively. The pH optima values for lignin peroxidases of the above ligninolytic fungal strains were found to be 2.5, 2.4, 2.4, 2.25, 2.5 and 2.8 respectively, where as the temperature optima values were 25°C, 24°C, 25°C, 23°C, 24°C and 25°C respectively.

12.
Indian J Pharm Sci ; 71(2): 136-9, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20336211

RESUMO

Seventeen Indian folklore medicinal plants were investigated to evaluate antibacterial activity of aqueous, ethanol and acetone extracts against 66 multidrug resistant isolates of major urinary tract pathogens (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Enterococcus faecalis) by disc diffusion method. Ethanol extract of Zingiber officinale and Punica granatum showed strong antibacterial activity against Escherichia coli. Ethanol extracts of Terminalia chebula and Ocimum sanctum exhibited antibacterial activity against Klebsiella pneumoniae. Ethanol extract of Cinnamomum cassia showed maximum antibacterial activity against Pseudomonas aeruginosa while ethanol extract of Azadirachta indica and Ocimum sanctum exhibited antibacterial activity against Enterococcus faecalis. The results support the folkloric use of these plants in the treatment of urinary tract infections by the tribals of Mahakoshal region of central India.

13.
Phys Med Biol ; 53(18): 5107-21, 2008 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-18723932

RESUMO

The performance of high-sensitivity x-ray imagers may be limited by additive instrumentation noise rather than by quantum noise when operated at the low exposure rates used in fluoroscopic procedures. The equipment-invasive instrumentation noise measures (in terms of electrons) are generally difficult to make and are potentially not as helpful in clinical practice as would be a direct radiological representation of such noise that may be determined in the field. In this work, we define a clinically relevant representation for instrumentation noise in terms of noise-equivalent detector entrance exposure, termed the instrumentation noise-equivalent exposure (INEE), which can be determined through experimental measurements of noise-variance or signal-to-noise ratio (SNR). The INEE was measured for various detectors, thus demonstrating its usefulness in terms of providing information about the effective operating range of the various detectors. A simulation study is presented to demonstrate the robustness of this metric against post-processing, and its dependence on inherent detector blur. These studies suggest that the INEE may be a practical gauge to determine and compare the range of quantum-limited performance for clinical x-ray detectors of different design, with the implication that detector performance at exposures below the INEE will be instrumentation-noise limited rather than quantum-noise limited.


Assuntos
Algoritmos , Artefatos , Análise de Falha de Equipamento/métodos , Radiografia/instrumentação , Análise de Falha de Equipamento/normas , Radiografia/métodos , Radiografia/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estados Unidos
14.
Drugs Today (Barc) ; 44(11): 837-44, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19180261

RESUMO

Certolizumab pegol is a humanized Fab' fragment monoclonal antibody to tumor necrosis factor alpha (TNF-alpha). PEGylation increases its half-life, and it is administered subcutaneously to treat immune-mediated inflammatory diseases such as Crohn's disease and rheumatoid arthritis. Certolizumab pegol improves quality of life and reduces clinical disease activity. Inflammatory markers such as C-reactive protein (CRP) also decrease after administration of certolizumab pegol. The dose for induction of remission is 400 mg subcutaneously at weeks 0, 2 and 4. The dose for maintenance of remission is 400 mg sc given every four weeks. The safety profile is comparable with other anti-TNF agents, and the major adverse events are related to infections. This article reviews the published data regarding the efficacy and safety of certolizumab pegol.


Assuntos
Doença de Crohn/tratamento farmacológico , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Polietilenoglicóis/uso terapêutico , Anticorpos Monoclonais Humanizados , Certolizumab Pegol , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Doença de Crohn/imunologia , Doença de Crohn/fisiopatologia , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/farmacologia , Injeções Subcutâneas , Modelos Químicos , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia
16.
J Nat Prod ; 62(1): 102-6, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9917292

RESUMO

A systematic structure-activity relationship study of plicatin B (1), an antimutagenic constituent of Psoralea juncea, was undertaken with a view toward elucidating its chemical mode of action and possibly optimizing its antimutagenic activity during the process. Compound 1 and its related analogues were examined for their antimutagenic activity against mutations induced by ethyl methanesulfonate, a direct acting mutagen and alkylating agent, in Salmonella typhimurium strain TA100, utilizing the modified Ames test protocol. The dihydro analogue 3 resulting from saturation of the conjugated alkene double bond of 1 was found to exhibit reduced cytotoxicity and enhanced efficacy relative to the parent compound. This result serves preliminarily to exclude a Michael acceptor role of the alpha,beta-unsaturated carbonyl moiety in connection with its antimutagenic activity.


Assuntos
Acrilatos/química , Acrilatos/farmacologia , Antimutagênicos/química , Antimutagênicos/farmacologia , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Testes de Mutagenicidade , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Salmonella typhimurium/genética , Relação Estrutura-Atividade
17.
J Immunol ; 154(12): 6246-51, 1995 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-7759862

RESUMO

There is considerable evidence to suggest that an FcR similar in structure to class I MHC Ags, neonatal Fc receptor (FcRn), transports IgG across the intestinal epithelium of suckling mice. However, this has not previously been shown definitively, nor has it been shown whether FcRn is the only, or even the major, IgG transporter in the neonatal mouse gut. We report here that neonatal mice homozygous for a targeted disruption of the beta 2microglobulin (beta 2m) gene, which encodes one subunit of FcRn, had reduced FcRn alpha-chain at the lumenal plasma membrane of intestinal cells. These mice had strikingly lower serum IgG levels during the first month after birth than littermates that possessed functional FcRn. Furthermore, we found by fostering mice on mothers with a different IgG allotype that all of the IgG in sera of beta 2m-/- mice was endogenous, and that none was obtained from milk. We conclude that FcRn is the only transporter of IgG from mother to young in the mouse. The onset of IgG synthesis in mice that received no milk IgG lagged behind that in siblings with normal IgG transport, suggesting that maternal IgG stimulates Ab production in the neonate. We noted no difference between the IgG concentrations in the milk of beta 2m-/- and beta 2m+/- mice, indicating that FcRn is not involved in the secretion of IgG into milk.


Assuntos
Imunoglobulina G/metabolismo , Receptores de IgG/metabolismo , Microglobulina beta-2/imunologia , Animais , Animais Recém-Nascidos , Transporte Biológico Ativo , Feminino , Feto/imunologia , Feto/metabolismo , Imunidade Materno-Adquirida , Alótipos de Imunoglobulina/sangue , Alótipos de Imunoglobulina/metabolismo , Imunoglobulina G/sangue , Intestinos/imunologia , Masculino , Camundongos , Camundongos Mutantes , Microvilosidades/imunologia , Microvilosidades/metabolismo , Leite/imunologia , Gravidez , Receptores de IgG/genética , Microglobulina beta-2/deficiência , Microglobulina beta-2/genética
18.
Horm Metab Res ; 27(1): 19-22, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7729787

RESUMO

Because of the demonstration of a genetic linkage between glucokinase and Type II diabetes, and the central role of glucokinase on glucose metabolism, we studied glucokinase activity in the liver of patients with and without Type II diabetes. Glucokinase activity was decreased by about 50% in obese subjects with diabetes (n = 12) compared with (p < 0.01) lean controls (n = 9) and (p < 0.05) obese controls (n = 10). There was no difference between lean and obese controls. Fifty percent of subjects with diabetes had lower liver glucokinase activity than the lowest value of the controls. These data further support the important role that glucokinase plays in the pathogenesis of Type II diabetes.


Assuntos
Diabetes Mellitus Tipo 2/enzimologia , Glucoquinase/metabolismo , Fígado/enzimologia , Adulto , Glicemia/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Brain Res Bull ; 27(6): 849-52, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1686215

RESUMO

Recent experimental data indicate that endogenous brain ligands for the opioid receptors such as enkephalins, beta-endorphin (beta-End) and dynorphin (Dyn) may be involved in both generalized and partial seizures. The "tottering" (tg/tg) mouse provides an electrophysiological representation of generalized spontaneous human epilepsy. These mice exhibit behavioral absence seizures with accompanying spike-wave discharges. Methionine-enkephalin (M-Enk), beta-End and Dyn levels in various regions of brain were measured by radioimmunoassay (RIA) in 15-18-week-old tg/tg and control (+/+) mice to elucidate the relation between seizures and the opioid system. beta-End and Dyn levels were similar in tg/tg and +/+ mice. However, M-Enk levels were significantly increased in the striatum, cortex, pons and medulla of the tg/tg mice. Our data suggest that in the tottering mouse model of generalized epilepsy there is an alteration of enkephalinergic pathways and not of the endorphinergic or dynorphinergic pathways.


Assuntos
Encefalina Metionina/metabolismo , Epilepsia/metabolismo , Animais , Encéfalo/metabolismo , Dinorfinas/metabolismo , Epilepsia/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes Neurológicos , Concentração Osmolar , Radioimunoensaio , Distribuição Tecidual , beta-Endorfina/metabolismo
20.
Metabolism ; 40(9): 883-7, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1895952

RESUMO

The genetics of malignant hyperthermia (MH) are ill-understood; however, the association of Duchenne muscular dystrophy (DMD) with MH is well known. A deficiency of dystrophin is common to both the DMD and mdx mouse, an animal model for DMD. Using muscle contracture tests for MH, we have shown that in the mdx mouse there is no MH susceptibility, suggesting the lack of a direct role of the dystrophin in the development of MH syndrome.


Assuntos
Cafeína/farmacologia , Contratura/induzido quimicamente , Distrofina/deficiência , Halotano/farmacologia , Abdome , Animais , Combinação de Medicamentos , Distrofina/genética , Camundongos , Camundongos Mutantes , Concentração Osmolar
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