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1.
J Eur Acad Dermatol Venereol ; 38(2): 413-418, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37684051

RESUMO

BACKGROUND: Hereditary palmoplantar keratodermas (hPPKs) comprise a heterogeneous group of skin disorders characterized by persistent palmoplantar hyperkeratosis. Loss-of-function variants in a serine peptidase inhibitor, SERPINA12, have recently been implicated in autosomal recessive diffuse hPPK. The disorder appears to share similarities with another hPPK associated with protease overactivity, namely Nagashima-type PPK (NPPK) caused by biallelic variants in SERPINB7. OBJECTIVES: The aim of this study was to enhance the understanding of the clinical and genetic characteristics of serine protease-related hPPKs caused by variants in SERPINA12 and SERPINB7. METHODS: Whole-exome sequencing (WES) was performed for hPPK patients. Haplotype analysis was completed for the patients with identified recessive SERPINA12 variants and their available family members. In addition, the current literature of SERPINA12- and SERPINB7-related hPPKs was summarized. RESULTS: The phenotype of SERPINA12-related hPPK was confirmed by reporting three new SERPINA12 patients, the first of European origin. A novel SERPINA12 c.1100G>A p.(Gly367Glu) missense variant was identified confirming that the variant spectrum of SERPINA12 include both truncating and missense variants. The previously reported SERPINA12 c.631C>T p.(Arg211*) was indicated enriched in the Finnish population due to a plausible founder effect. In addition, SERPINA12 hPPK patients were shown to share a similar phenotype to patients with recessive variants in SERPINB7. The shared phenotype included diffuse transgradient PPK since birth or early childhood and frequent palmoplantar hyperhidrosis, aquagenic whitening and additional hyperkeratotic lesions in non-palmoplantar areas. SERPINA12 and SERPINB7 hPPK patients cannot be distinguished without genetic analysis. CONCLUSIONS: Recessive variants in SERPINA12 and SERPINB7 leading to protease overactivity and hPPK produce a similar phenotype, indistinguishable without genetic analysis. SERPINA12 variants should be assessed also in non-Asian patients with diffuse transgradient PPK. Understanding the role of serine protease inhibitors will provide insights into the complex proteolytic network in epidermal homeostasis.


Assuntos
Hiperidrose , Ceratodermia Palmar e Plantar , Serpinas , Humanos , Pré-Escolar , Mutação , Ceratodermia Palmar e Plantar/genética , Ceratodermia Palmar e Plantar/patologia , Mutação de Sentido Incorreto , Peptídeo Hidrolases/genética , Serpinas/genética
4.
Biochim Biophys Acta ; 1196(2): 201-8, 1994 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-7841184

RESUMO

Antisense oligonucleotides (ODNs) are promising novel therapeutic agents against viral infections and cancer. However, problems with their inefficient delivery and inadequate stability have to be solved before they can be used in therapy. To circumvent these obstacles, a wide variety of improvements, including phosphorothioate ODNs and liposomes as a carrier system, have been developed. This study was designed to compare the effects of two cationic liposomes on the intracellular delivery and stability of ODNs in CaSki cell cultures. Also the stability of 3'-end phosphorothioate ODNs were investigated. The 3'-modification neither had any effect on the delivery, nor protected the ODNs against degradation. The cellular delivery and stability of ODNs was improved with both cationic liposomes, but a cationic liposomal preparations containing dimethyldioctadecylammonium bromide and dioleoylphosphatidylethanolamine (DDAB/DOPE) was more efficient than commercially available N-(1-(2,3-dioleoyloxy)propyl)-N,N,N-trimethylammoniummethylsulf ate (DOTAP). The improved cellular delivery was largely due to the stabilization of ODNs by cationic liposomes. The improved stability in the culture medium indicates that the cationic liposomes per se protect the ODNs from enzymatic degradation. Indeed, intact ODNs were found in the cytoplasm and nucleus only when delivered by cationic liposomes.


Assuntos
Oligonucleotídeos Antissenso/administração & dosagem , Sequência de Bases , Cátions , Meios de Cultura/química , Portadores de Fármacos , Estabilidade de Medicamentos , Ácidos Graxos Monoinsaturados , Humanos , Lipossomos , Dados de Sequência Molecular , Fosfatidiletanolaminas , Compostos de Amônio Quaternário , Células Tumorais Cultivadas
5.
APMIS ; 113(7-8): 497-505, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16086819

RESUMO

Temporin A (TA), a short alpha-helical antimicrobial peptide isolated from the skin of the frog Rana temporaria, is effective against a broad spectrum of Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium strains. TA interacts directly with the cell membrane of the microorganism and it has been reported to be non-toxic to erythrocytes at concentrations that are antimicrobial. Less is known about the effects on the viability and growth of nucleated eukaryotic cells. In this study we have tested antibacterial and growth-inhibitory properties of TA, its dimeric analogue (TAd), and all-L (TAL L512) and all-D (TAD L512) enantiomeric derivatives of modified TA towards S. aureus and cultured human keratinocytes, respectively. All molecules were antibacterial at concentrations from 1.5 microM to 10 microM. In keratinocyte cultures, TAD L512, as well as TAd, showed cytotoxicity. The original TA and TAL L512 did not affect the viability of the cells at their bacteriolytic concentrations. The growth of keratinocytes in low- and high-calcium media was only slightly inhibited by temporins at concentrations which were antibacterial to S. aureus. This suggests that original TA and its modification, TAL L512, are promising molecules against multiresistant bacterial infections.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Proteínas/química , Proteínas/farmacologia , Sequência de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos/toxicidade , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Dimerização , Farmacorresistência Bacteriana Múltipla , Enterococcus faecium/efeitos dos fármacos , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Proteínas/toxicidade , Rana temporaria , Staphylococcus aureus/efeitos dos fármacos , Estereoisomerismo
7.
Eur J Cancer ; 34(3): 329-36, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9640217

RESUMO

Mantle cell lymphoma (MCL) is a subtype of B-cell non-Hodgkin's lymphoma recently recognised as a distinct disease entity. Little is known about the prognostic factors and optimal treatment of MCL. The aim of this study was to analyse retrospectively the clinical features and effect of treatment in 94 MCL patients diagnosed and treated in one centre between 1980 and 1996, and to find out different factors influencing the treatment results and prognosis. The median age of the patients was 66 years, and 77% were over 60 years old. Of the patients, 76% had advanced disease, the performance status (PS) was WHO 0-1 in 86%, and B symptoms were present in 35% of the cases. Bone marrow infiltration was found in 61% and overt leukaemia in 12% of the patients. Of the patients, 47% achieved complete remission with first- or second-line therapy. The median duration of remission, time to treatment failure (TTF), and survival were 28, 18, and 41 months, respectively. In multivariate analyses, age, stage and leukaemic disease were significantly associated with TTF, and age, stage, leukaemic disease and lactate dehydrogenase (LDH) with survival. Long-term prognosis is poor in MCL. None of the conventional chemotherapies seems curative. A prospective randomised trial should be made to evaluate the benefit of anthracycline-containing regimens in MCL.


Assuntos
Linfoma não Hodgkin , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Indução de Remissão , Estudos Retrospectivos , Análise de Sobrevida , Taxa de Sobrevida , Resultado do Tratamento
8.
J Histochem Cytochem ; 45(2): 265-74, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9016315

RESUMO

Synthesized oligonucleotides are used in anti-sense and anti-gene technology to control gene expression. Because cells do not easily take up oligonucleotides, cationic liposomes have been employed to facilitate their transport into cells. Although cationic liposomes have been used in this way for several years, the precise mechanisms of the delivery of oligonucleotides into cells are not known. Because no earlier reports have been published on the liposomal delivery of oligonucleotides at the ultrastructural level, we performed a study, using electron microscopy, on the cellular uptake and intracellular distribution of liposomal digoxigenin-labeled oligodeoxynucleotides (ODNs) at several concentrations (0.1, 0.2, an 1.0 microM) in CaSki cells. Two cationic lipids (10 microM) were compared for transport efficiency: polycationic 2,3-dioleoyloxy-N-[2(sperminecarboxamido)ethyl]-N,N-dimethyl -1-propanaminium trifluoroacetate (DOSPA) and monocationic dimethyl-dioctadecylammonium bromide (DDAB). Both liposomes contained dioleoyl-phosphatidylethanolamine (DOPE) as a helper lipid. Endocytosis was found to be the main pathway of cellular uptake of liposomal ODNs. After release from intracellular vesicles, ODNs were carried into the perinuclear area. The nuclear membrane was found to be a barrier against the penetration of ODNs delivered by liposomes into the nucleus. Release from vesicles and transport into the nuclear area was faster when the oligo-DDAB/DOPE complex had a positive net charge (0.1 and 0.2 microM ODN concentrations), and only under this condition were some ODNs found in nucleoplasm. Although DOSPA/DOPE could also efficiently deliver ODNs into the cytosol, no ODNs were found in nucleoplasm. These findings suggest that both the type of liposome and the charge of the oligo-liposome complex are important for determination of the intracellular distribution of ODNs.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Lipossomos , Oligonucleotídeos/administração & dosagem , Feminino , Humanos , Microscopia Eletrônica , Oligonucleotídeos/farmacocinética , Fosfatidiletanolaminas , Compostos de Amônio Quaternário , Distribuição Tecidual , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/metabolismo
9.
Antiviral Res ; 23(2): 119-30, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8147581

RESUMO

The "high risk" types 16 and 18 of human papillomavirus (HPV) are involved in the etiology of genital squamous cell carcinoma. The early genes 6 and 7 (E6-E7) of these viruses code for the major transforming proteins, capable of inducing cell transformation alone or acting synergistically with other oncogenes. Antisense oligonucleotides, recently applied to inhibit the functions of a number of cellular and viral proteins, might provide the basis for a new therapeutic strategy against HPV-induced malignancies. We studied the proliferation of CaSki cells by the MTT assay after their exposure to HPV 16 E7 mRNA antisense oligonucleotides with and without cationic liposomes (containing dimethyldioctadecylammonium bromide DDAB, and dioleylphosphatidylethanolamine, DOPE). Unmodified oligonucleotides (either 12- or 23-mers) did not have any effect on either CaSki cell proliferation or morphology when compared with the untreated cells. The cellular uptake of oligonucleotides was significantly enhanced by the cationic liposomes as assessed by confocal laser scanning microscopy (CLSM). The cationic liposomes were toxic to the cells as demonstrated by the reduced cell number and altered cell morphology. Only a slight reduction of the cell proliferation was seen when antisense 12-mer was protected from its 3'- and 5'-ends with thiolate and FITC, respectively. Both the 12- and the 23-mers with the cationic liposomes inhibited cell proliferation, the inhibitory effect being longer with the 23-mer. Overall, the MTT assay was less sensitive than light microscopy to reveal the toxic effects on CaSki cells. The results suggest that antisense oligonucleotides targeted to HPV 16 E7 mRNA can be introduced into CaSki cells with cationic liposomes.


Assuntos
Divisão Celular/efeitos dos fármacos , Oligonucleotídeos Antissenso/administração & dosagem , Proteínas Oncogênicas Virais/genética , Papillomaviridae/genética , RNA Viral/genética , Sequência de Bases , Cátions , Linhagem Celular Transformada , Colorimetria/métodos , Portadores de Fármacos , Formazans , Humanos , Lipossomos/toxicidade , Microscopia de Fluorescência , Dados de Sequência Molecular , Oligonucleotídeos Antissenso/síntese química , Oligonucleotídeos Antissenso/farmacocinética , Oligonucleotídeos Antissenso/farmacologia , Proteínas E7 de Papillomavirus , RNA Mensageiro/genética , Sais de Tetrazólio , Células Tumorais Cultivadas
10.
Leuk Lymphoma ; 24(1-2): 165-74, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9049973

RESUMO

Cationic liposomes improve the delivery of antisense oligonucleotides (ODNs) into cells. However, there is marked variability in the cellular uptake of ODNs into different cell lines. We used liposomes containing dimethyloctadecylammonium bromide (DDAB) and dioleoylphosphatidylethanolamine (DOPE) to increase the delivery of phosphodiester ODNs into four different myeloma cell lines. The delivery by cationic liposomes increased the delivery of bcl-2 antisense ODNs by a factor of 9 to 45 as compared to plain ODNs. The stability of ODNs was increased with liposomes both in the culture medium and within the cells. Intact liposomal ODNs were detected inside the cells up to 24 hours with gel electrophoresis and phosphor imager analysis. Antisense ODNs had no effect on bcl-2 mRNA levels. Also the proliferation of myeloma cells remained unchanged during the 3-day incubation period. Our study shows that liposomal antisense ODNs targeting bcl-2 of human myeloma cells result in increased stability of ODNs with minimal toxicity. However, further modifications are needed to gain biological effects of antisense ODNs on human myeloma cells.


Assuntos
Marcação de Genes , Genes bcl-2 , Mieloma Múltiplo/terapia , Oligonucleotídeos Antissenso/administração & dosagem , Fosfatidiletanolaminas/administração & dosagem , Compostos de Amônio Quaternário/administração & dosagem , Cátions , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Portadores de Fármacos , Estabilidade de Medicamentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Lipossomos , Células Tumorais Cultivadas
11.
J Magn Reson ; 137(1): 243-6, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10053154

RESUMO

A new method for the measurement of homonuclear 3J(HNHalpha) coupling constants in 15N-labeled small proteins is described. The method is based on a modified sensitivity enhanced HSQC experiment, where the 3J(HNHalpha) couplings are multiplied in the f1-dimension. The J-multiplication of homonuclear 3J(HNHalpha) couplings is based on simultaneous incrementation of 15N chemical shift and homonuclear coupling evolution periods. The time increment for the homonuclear coupling evolution period is chosen to be a suitable multiple (2N x t1) of the corresponding increment for 15N-shift evolution. This results in the splitting of the HSQC correlation in the f1-dimension by 2N x 3J(HNHalpha). Because the pulse sequence has good sensitivity and water suppression properties, it is particularly useful for natural abundance samples.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Ubiquitinas/química , Processamento de Imagem Assistida por Computador , Estrutura Molecular , Isótopos de Nitrogênio/análise , Marcadores de Spin , Água/química
12.
Fertil Steril ; 55(2): 276-80, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1846825

RESUMO

We compared pituitary response in the corticotropin-releasing hormone (CRH) test between 9 eumenorrheic and 10 amenorrheic endurance athletes. The maximal oxygen capacity (VO2max), determined using an exercise test on a bicycle ergometer, was larger in amenorrheic (62.7 +/- 1.0 SE mL/min per kg) than in eumenorrheic (54.7 +/- 2.3 mL/min per kg) athletes. A 100 micrograms bolus of human CRH was administered intravenously, and blood samples were collected at -15, 0, 30, 60, 90, and 120 minutes. The mean basal concentrations of endorphins, adrenocorticotropic hormone (ACTH), and cortisol did not show significant differences between the groups. The cumulative response of ACTH in the CRH test was larger in eumenorrheic (7.7 +/- 1.3 pmol/L) than in amenorrheic (3.6 +/- 0.6 pmol/L) athletes, but the response of endorphins and cortisol did not differ between the groups. A negative correlation was found between the VO2max and the ACTH response during the CRH test in the total group of athletes. These findings indicated changes in the function of hypothalamic-pituitary-adrenal axis in amenorrheic athletes that can be attributed to intensive training.


Assuntos
Hormônio Adrenocorticotrópico/sangue , Amenorreia/sangue , Hormônio Liberador da Corticotropina , Endorfinas/sangue , Hidrocortisona/sangue , Hormônio Luteinizante/sangue , Menstruação/sangue , Esportes , Adolescente , Feminino , Humanos , Esforço Físico , Radioimunoensaio , Valores de Referência
13.
Clin Chim Acta ; 195(1-2): 57-66, 1990 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-2093479

RESUMO

Placenta secretes corticotropin-releasing hormone (CRH) into the maternal and fetal circulation, but a CRH binding protein in plasma may decrease its biological activity. Using a charcoal adsorption method we found that 92% of added 125I-Tyr-CRH was bound to a binding protein in the nonpregnant plasma, 72% in the plasma at term pregnancy, 90% in umbilical cord plasma, 82% in the amniotic fluid in the second and 25% in the third trimester. CRH added to plasma inhibited the binding of 125I-Tyr-CRH over the concentration range of 0.1-8.8 nmol/l in plasma and of 0.1-2.2 nmol/l in amniotic fluid. There was a significant negative correlation (R = -0.80) between the binding capacity of the CRH-binding protein and CRH concentration in maternal plasma. Plasma or amniotic fluid was incubated with 125I-Tyr-CRH and subjected to gel filtration on Sephadex G-50. The bound radioactivity was eluted at the region of Mr 25-40 kDa and the unbound radioactivity at the location of synthetic CRH. Bound and unbound CRH concentrations were determined using charcoal adsorption method and gel filtration on Sephadex G-50 in ten maternal plasma samples at the third trimester of pregnancy. Following mean percentages were found to be bound: charcoal method 61.9 +/- 6.80% (SE) and gel filtration 62.8 +/- 6.33%. We conclude that the bulk of CRH is bound to a binding protein in maternal and fetoplacental circulation, whereas at term pregnancy the role of the binding is small in amniotic fluid.


Assuntos
Líquido Amniótico/metabolismo , Hormônio Liberador da Corticotropina/metabolismo , Sangue Fetal/metabolismo , Adsorção , Ligação Competitiva , Carvão Vegetal , Cromatografia em Gel , Hormônio Liberador da Corticotropina/sangue , Feminino , Humanos , Radioisótopos do Iodo , Placenta/metabolismo , Gravidez , Terceiro Trimestre da Gravidez
14.
Anticancer Res ; 16(5A): 2485-92, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8917339

RESUMO

Despite the known association of human papillomavirus (HPV) infection with cervical cancer there is no specific antiviral treatment for HPV infection. Antisense oligode-oxynucleotides (AS-ODNs) may offer an effective way to treat HPV infections as the stability and delivery have been improved using modified ODNs or carrier systems. In this study we investigated the effects of liposomal AS-ODNs (0.1, 1 and 5 microM) on HPV 16 E7 mRNA and protein levels in CaSki cells. We used cationic liposomes (10 microM) containing dimethyldioctadecylammonium bromide (DDAB) or 2,3-dioleyloxy-N-[2(sperminecar-boxamido)ethyl]-N, N-dimethyl-1-propanaminium trifluoroacetate (DOSPA). Both these liposomes had dioleoylphosphatidyl-ethanolamine (DOPE) as a helper lipid. The target of the AS-ODNs was E7 protein because it is the one of the two oncoproteins of HPV 16. Only liposomal AS-ODNs which were targeted to the initiation codon of E7, had an effect on E7 mRNA expression; two shorter transcripts were detected, suggesting that RNase H degradation was activated. Liposomal random ODN or liposomal ODN targeted downstream from the initiation site of E7 did not affect the mRNA pattern. However, no change was found in the E7 protein levels detected by immunoprecipitation. Further studies showed that AS-ODNs inhibited the translation of E7 mRNA in a rabbit reticulocyte lysate assay. This data, together with the changes in mRNA levels, proved that the AS-ODNs reached the target mRNA. One possible explanation for the unchanged protein level of E7 in CaSki cells might be that immunoprecipitation is not sensitive enough to detect minor changes in protein levels. However, further progress is still needed in the field of carrier systems and modifications of AS-ODNs before non-sequence specific effects can be avoided.


Assuntos
Antivirais/farmacologia , Oligonucleotídeos Antissenso/farmacologia , Proteínas Oncogênicas Virais/efeitos dos fármacos , RNA Mensageiro/efeitos dos fármacos , RNA Viral/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Portadores de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Lipossomos , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus , Biossíntese de Proteínas/efeitos dos fármacos , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , Células Tumorais Cultivadas , Neoplasias do Colo do Útero
15.
Eur J Obstet Gynecol Reprod Biol ; 39(1): 19-24, 1991 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-1851489

RESUMO

The concentration of corticotropin-releasing hormone (CRH) in maternal plasma increases greatly during the last trimester of normal pregnancy. This CRH has been proposed to originate from the placenta. We studied plasma immunoreactive CRH in 46 uncomplicated pregnancies, in 10 pregnant women with chronic hypertension, in 17 women with pregnancy-induced hypertension (PIH) and in 24 women with pre-eclampsia, and correlated it to the levels of corticotropin (ACTH) and cortisol. CRH levels were greatly increased in women with pre-eclampsia, less significantly in women with PIH, while no change was found in pregnant women with chronic hypertension. ACTH levels also were increased in pregnancies with pre-eclampsia or PIH and there was a positive correlation between CRH and ACTH levels. CRH levels in cord venous plasma were significantly increased in pregnancies with pre-eclampsia but cortisol did not show any significant increase. These findings suggest that placental release of CRH into the maternal and fetal circulation is increased in pre-eclampsia.


Assuntos
Hormônio Liberador da Corticotropina/sangue , Sangue Fetal/química , Hipertensão/metabolismo , Pré-Eclâmpsia/sangue , Hormônio Adrenocorticotrópico/sangue , Adulto , Feminino , Humanos , Hidrocortisona/sangue , Placenta/metabolismo , Gravidez , Terceiro Trimestre da Gravidez
16.
Sci Total Environ ; 266(1-3): 153-8, 2001 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-11258812

RESUMO

A novel sediment bubble gas sampler and a subsurface bubble gas collector were designed to measure the ebullition of gases from profundal sediments of aquatic ecosystems. The sediment gas sampler was constructed to collect bubble gas samples directly from the uppermost sediment layers for gas composition analysis. The floating subsurface gas collector, designed to trap the bubbles released naturally from sediments, permitted the measurement of both the volume and the composition of the bubble gas. Due to its low cost, light weight and rapid sampling capability, the gas collector is ideal for studies requiring many replicate collectors. These devices were used for measurement of the ebullition of methane (CH4) and carbon dioxide (CO2) during an open water period from hypereutrophic Lake Postilampi, situated within the midboreal zone in Finland. The bubble gas obtained from the sediment with the sediment gas sampler had higher concentrations of CH4 and CO2 than the bubbles trapped in the gas collectors. This indicated that the bubble gas composition changed, either naturally during the migration of the bubbles from the sediment through the water column to the gas collectors, and/or during their storage in the collectors prior to sampling. The mean CH4 ebullition from Lake Postilampi was estimated to be in the range from 36 to 46 mg m(-2 d(-1), based on the bubble gas CH4 concentrations measured from the gas collectors and sediment, respectively. The bubbles contained only 0.02-0.57% of CO2 and thus, the ebullition had no significance in the release of CO2 from the lake.


Assuntos
Dióxido de Carbono/análise , Monitoramento Ambiental/instrumentação , Sedimentos Geológicos/química , Metano/análise , Gases/análise , Movimentos da Água
17.
Chemosphere ; 50(2): 247-50, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12653296

RESUMO

The springtime methane (CH4) emission from a small, eutrophied boreal lake was assessed during the winter ice-cover by measurement of gas ebullition and CH4 accumulation in the water column in association with the development of oxygen depletion after ice formation. The winter CH4 production was estimated to result in a loss of 3.6-7.9 g CH4 m(-2) from the lake to the atmosphere during the short period of ice melt. This could account for 22-48% of the annual CH4 emission from the pelagic zone of the lake. The contribution of winter to the annual CH4 release can be similar or even higher in seasonally ice-covered northern aquatic ecosystems than in northern terrestrial wetlands, thus winter must be considered in any studies into the aquatic CH4 emissions. The trophic state and wintertime oxygen conditions, linked to the changes in land-use in the catchments and climate, are important factors controlling the springtime lake CH4 emissions.


Assuntos
Eutrofização , Água Doce/química , Gelo , Metano/análise , Estações do Ano , Oxigênio/química
18.
AJNR Am J Neuroradiol ; 34(1): 198-204, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22766677

RESUMO

BACKGROUND AND PURPOSE: Peripheral AVM is a locally aggressive disease with a high tendency to recur; its treatment is complex, especially in the anatomically delicate head and neck area. Here, we report results of ethanol sclerotherapy for head and neck AVM and discuss its potential use for peripheral AVM. MATERIALS AND METHODS: We retrospectively assessed degree of AVM eradication, complications, and clinical or imaging signs of recurrence for 19 patients treated with ethanol sclerotherapy for head and neck AVM (1 intraosseous, 18 soft-tissue AVMs). RESULTS: Of the 19 patients, 11 had complete eradication of arteriovenous shunting at DSA, with 1 recurrence (mean follow-up 15 months), and for 7 patients, treatment is ongoing. During 59 treatment sessions, 12 patients experienced 14 complications, 1 leading to permanent functional damage. CONCLUSIONS: Ethanol sclerotherapy has potential for complete eradication of head and neck AVM with low recurrence within the first year after completion of treatment. Complete eradication may require several treatment sessions during which complications should be minimized with careful techniques.


Assuntos
Malformações Arteriovenosas/diagnóstico por imagem , Malformações Arteriovenosas/terapia , Etanol/uso terapêutico , Escleroterapia/métodos , Adolescente , Adulto , Criança , Feminino , Cabeça , Humanos , Masculino , Pessoa de Meia-Idade , Pescoço , Radiografia , Soluções Esclerosantes/uso terapêutico , Resultado do Tratamento , Adulto Jovem
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