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1.
Heliyon ; 9(8): e18505, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37560649

RESUMEN

The risk of CO2 leakage from carbon capture, utilization, and storage (CCUS) wells and geological storage sites must be properly assessed before the implementation of CO2 injection. According to ISO 27914 and ISO/FDIS 27916, the design and construction of an injection well needs to guarantee safety and ability to contain the stored CO2 over a long-term period. However, these standards alone were inadequate to evaluate the well integrity due to the need to specify criteria, duration of measurement, and range of measurement parameters of the available tools according to industries' best practices. The methodology used in the study adapted applicable and readily-available international standards, field experiences, and lessons learned that could be used to support the construction of new and/or the conversion of existing oil and gas wells into CO2 injection wells. This study focused on Jepon-1 in Gundih field, Indonesia, an abandoned oil and gas well. Its actual conditions, well integrity, capabilities of the equipment used in the workover and logging operations, and its limitations in checking the conditions of various crucial aspects of integrity, were evaluated. The results showed that the application of the international standards could not fulfill all the detailed requirements of integrity evaluation of the JPN-1 well due to its particular condition and situation. Other field experiences needed to be adapted, improved, and incorporated in the integrity evaluation of this well. Additionally, longer duration of measurement and more accurate and sensitive logging evaluation tools, combined with temperature logging tools, are required to detect leakage that could not be identified by the commercial tools used in this well. The result of this well integrity study will be used as a fundamental basis for constructing CCUS well regulations by the Government and stakeholders.

2.
Eur Rev Med Pharmacol Sci ; 25(3): 1670-1679, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33629337

RESUMEN

The emergence of Coronavirus Disease 19 (COVID-19) as a pandemic has claimed hundreds of thousands of lives worldwide since its initial breakout. With increasing reports from clinical observations and autopsy findings, it became clear that the disease causes acute respiratory distress syndrome (ARDS), as well as a broad spectrum of systemic and multiorgan pathologies, including angiopathy, endothelialitis, and thrombosis. Coagulopathy is associated with the activity of megakaryocytes, which play crucial roles in modulating the platelet homeostasis. Only a few autopsy reports include findings on thrombosis formation and the presence of megakaryocytes. Here we review and summarize the possible involvement and the pathophysiology of the thromboembolic events in COVID-19 patients based on post-mortem reports. We reviewed post-mortem reports from March 2020 to September 2020. Eleven autopsy reports that demonstrated thromboembolic involvement findings, either macroscopically or microscopically, were included in this review. All studies reported similar pulmonary gross findings. Not all studies described thrombi formation and megakaryocyte findings. Pulmonary embolism, coagulopathy, severe endothelial injury, and widespread thrombosis are frequent in COVID-19 patients, following many patients with high-level D-Dimer, increased fibrinogen, abnormal prothrombic coagulation, and thrombocytopenia. Reports showed that thrombus was also found in the lower extremities' deep veins and the prostatic venous plexus. In conclusion, a complex interaction of SARS-CoV-2 virus invasion with platelets, leukocytes, endothelial cells, inflammation, immune response, and the possible involvement of megakaryocytes may increase the cumulative risk of thrombosis by a yet unclear cellular and humoral interaction.


Asunto(s)
COVID-19/mortalidad , Endotelio Vascular/patología , SARS-CoV-2 , Tromboembolia/mortalidad , Autopsia , Coagulación Sanguínea , COVID-19/complicaciones , COVID-19/patología , Humanos , Pulmón/irrigación sanguínea , Pulmón/patología , Megacariocitos/patología , Pandemias , Tromboembolia/etiología , Tromboembolia/patología
3.
Placenta ; 23(5): 373-9, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12061852

RESUMEN

This study was undertaken to compare placental levels of 2,3-Dioxygenase (IDO), a free radical scavenger, and 4-Hydroxynonenal (4-HNE), a major by-product of lipid peroxidation, in normal and pre-eclamptic pregnancies. Placentae were collected at caesarean section from women with a term, normal singleton pregnancy (37-40 weeks' gestation, n=10) and women with a term singleton pregnancy complicated by pre-eclampsia (n=10). IDO and 4-HNE localization and intensity was studied by semi-quantitative immunohistochemistry and differences between groups were analysed using the Mann-Whitney U test. Immunostaining for IDO was located primarily in endothelial cell nuclei, with a reduced level of staining in the cytoplasm, in most capillaries from all placentae examined. A significantly higher level of IDO immunostaining was observed in normal placentae compared to pre-eclamptic placentae (P=0.008). 4-HNE was located mainly in the cytoplasm of syncytiotrophoblast cells of all placentae examined. There were no significant differences in the pattern or intensity of 4-HNE immunostaining levels between normal and pre-eclamptic pregnancies (P=0.684). Our IDO results support the hypothesis of decreased anti-oxidative capability in the placenta and the possibility of an ineffective compensatory mechanism against increased oxidative stress in the fetus.


Asunto(s)
Aldehídos/metabolismo , Dioxigenasas , Oxigenasas/metabolismo , Placenta/enzimología , Preeclampsia/enzimología , Embarazo/metabolismo , Adulto , Núcleo Celular/enzimología , Endotelio Vascular/enzimología , Femenino , Edad Gestacional , Humanos , Técnicas para Inmunoenzimas , Indolamina-Pirrol 2,3,-Dioxigenasa
4.
Plant Physiol ; 123(4): 1517-24, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10938367

RESUMEN

We have selected 143 independent Nicotiana plumbaginifolia cell lines that survive in the presence of 5-fluoroorotic acid. These lines show several diverse phenotypes. The majority of these cell lines showed reduced levels of UMP synthase. However, one particular phenotype, which represents 14% of the total independent lines (20 cell lines), showed an unexpected, high level of UMP synthase and was therefore analyzed in detail. The selected cell lines showed no differences with wild-type cells with respect to uptake of orotic acid, affinity of UMP synthase for its substrates, or UMP synthase gene-copy number. Alternative detoxification mechanisms were also excluded. The elevated enzyme activity was correlated with elevated UMP synthase protein levels as well as elevated UMP synthase mRNA levels. In contrast to wild-type cell lines, the fluoroorotic acid-selected cell lines did not respond to thymine or to other biochemicals that affect thymine levels. In addition, there was also a concomitant up-regulation of aspartate transcarbamoylase, however, dihydroorotase and dihydroorotate dehydrogenase are not up-regulated in these cell lines.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Complejos Multienzimáticos/genética , Nicotiana/genética , Orotato Fosforribosiltransferasa/genética , Ácido Orótico/análogos & derivados , Orotidina-5'-Fosfato Descarboxilasa/genética , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Plantas Tóxicas , Pirimidinas/biosíntesis , Timina/metabolismo , Aspartato Carbamoiltransferasa/metabolismo , Western Blotting , Línea Celular , Cromatografía en Capa Delgada , Dihidroorotasa/metabolismo , Dihidroorotato Deshidrogenasa , Complejos Multienzimáticos/metabolismo , Orotato Fosforribosiltransferasa/metabolismo , Ácido Orótico/farmacología , Orotidina-5'-Fosfato Descarboxilasa/metabolismo , Oxidorreductasas/metabolismo , Fenotipo , ARN Mensajero/análisis , Timina/farmacología , Nicotiana/enzimología , Nicotiana/metabolismo
5.
Plant Physiol ; 116(2): 815-21, 1998 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-9490773

RESUMEN

To understand the regulation and expression of pyrimidine biosynthesis in plants, we have examined the effect of the metabolic inhibitor 5-fluoroorotic acid (FOA) on uridine-5'-monophosphate synthase (UMPSase) expression in cell cultures of Nicotiana plumbaginifolia. UMPSase is the rate-limiting step of pyrimidine biosynthesis in plants. Addition of FOA causes an up-regulation of UMPSase enzyme activity in cell cultures after a lag phase of several days. Western-blot analysis demonstrated that the up-regulation in enzyme activity was caused by increased expression of the UMPSase protein. Northern-blot analysis demonstrated a higher level of UMPSase mRNA in the FOA-induced tissues than in control tissues. Run-on transcriptional assays showed that the UMPSase gene was transcriptionally activated after FOA treatment. The mechanism of toxicity of FOA is through thymine starvation. We found that addition of thymine abrogated the FOA-mediated up-regulation of UMPSase. In addition, methotrexate and aminopterin, which affect thymine levels by inhibiting dihydrofolate reductase, also up-regulate UMPSase in N. plumbaginifolia cells.

6.
Hum Reprod ; 10(10): 2579-83, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8567774

RESUMEN

Bleeding problems can be one of the major reasons for women to discontinue the use of hormonal contraceptives. Causes of endometrial bleeding can include disturbances in endometrial regeneration and angiogenesis. Endothelial cells migrate and proliferate rapidly as part of the angiogenic process under the influence of appropriate stimuli. The aim of this study is to investigate the production of endothelial cell migratory signals by endometrial explants from women receiving Norplant and to compare it to that of those with a normal menstrual cycle. The subjects were selected from Norplant users with an exposure of 3-9 months. The endothelial cell migratory signal production was assayed using the Folkman method (1989), modified by Rogers (1992). Blood serum concentrations of oestradiol, progesterone and sex hormone binding globulin were monitored for 2 weeks prior to endometrial biopsy. Endothelial cell migration toward endometrial explants of 30 women as control and 46 Norplant acceptors was assayed. The results showed that endothelial cell migratory activity toward endometrial explants from the control group was significantly higher than toward those from Norplant acceptors (z = 3.89, P < 0.001). There were no differences between endometrial endothelial cell migratory activities in Norplant acceptors with bleeding or without bleeding problems.


PIP: Researchers examined the production of endothelial cell migratory signals by endometrial explants from 46 Norplant acceptors aged 18-40 and compared it with endothelial cell migratory signals produced by endometrial explants from women using no hormonal contraception or an IUD and having a normal menstrual cycle. The results will provide insight into the role of endothelial cell migration in endometrial bleeding among Norplant acceptors. Both cases and controls attended the Raden Saleh Clinic in Jakarta, Indonesia. Health providers took peripheral blood samples 6 times at 2-3 day intervals before the endometrial biopsy to monitor serum levels of estradiol, progesterone, and sex hormone-binding globulin (SHBG). Laboratory researchers used a three-dimensional collagen matrix culture medium containing dispersed human umbilical vein endothelial cells as modified by Rogers (1992) to conduct the endothelial cell migration assay. Endothelial cell migration toward endometrial explants of the control group was much higher than toward those of the Norplant group (p 0.001). For example, 30 of 46 of the Norplant endometrial explants had a median endothelial cell migratory score of zero compared to 8 of the 30 control biopsies. In fact, only 1 of the control biopsies of the individual 500-cubic-micrometer explants did not respond, while 19 of the like Norplant explants did. In controls, endothelial cell migration was greater in the proliferative phase than in the secretory phases. Endothelial cell migration toward endometrial biopsies of Norplant acceptors with bleeding problems was the same as that toward Norplant acceptors with no bleeding problems. Serum levels of estradiol, progesterone, and SHBG were not associated with endothelial cell migration. These findings do not support the belief that increased angiogenesis in the endometrium of Norplant acceptors is responsible for endometrial bleeding.


Asunto(s)
Movimiento Celular , Anticonceptivos Femeninos/efectos adversos , Endotelio Vascular/citología , Levonorgestrel/efectos adversos , Transducción de Señal , Adolescente , Adulto , Biopsia , Células Cultivadas , Implantes de Medicamentos , Estradiol/sangre , Femenino , Humanos , Indonesia , Progesterona/sangre , Globulina de Unión a Hormona Sexual/metabolismo
7.
Plant Physiol ; 99(3): 1216-25, 1992 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16668991

RESUMEN

Uridine 5'-monophosphate (UMP) synthase mutants of tobacco have been produced from haploid cell-suspension cultures of a transgenic Nicotiana tabacum line, Tr25. The mutants were induced by incubating the suspension-cultured cells with 1 mmN-nitroso-N-methylurea for either 5 or 12 hours. Twenty mutant calli were isolated on selection medium containing 20 milligrams per liter of 5-fluoroorotic acid. Of those tested, most had reduced regeneration capacity. Characterization of UMP synthase activities in the isolated calli showed that UMP synthase activity varied from 8 to nearly 100% of the wild-type activity. The growth of the calli on the media containing different levels of 5-fluoroorotic acid correlated with decreasing UMP synthase activity. Because the UMP synthase enzyme has two separate enzymic activities (orotate phosphoribosyl transferase and orotidine-5'-monophosphate decarboxylase), several mutants were further characterized to determine how the mutations affected each of the two enzymic activities. In each case, the enzymic activity affected was the orotate phosphoribosyl transferase and not the orotidine-5'-monophosphate decarboxylase. The wound-inducible phenotype of the Tr25 plants as measured by the activation of the pin2-CAT gene remained unchanged by introduction of the UMP synthase mutations.

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