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1.
Macromol Rapid Commun ; 45(1): e2300225, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37247852

RESUMEN

Nonstoichiometric direct arylation polycondensation of 2,2',3,3',5,5',6,6'-octafluorobiphenyl with excess of 2,7-diiodo-9,9-dioctyl-9H-fluorene is demonstrated. Pd/Ag dual-catalyst system under water/2-methyltetrahydrofuran biphasic conditions enables direct arylation under mild conditions and promotes the intramolecular transfer of a Pd catalyst walking through the fluorene moiety. The nonstoichiometric direct arylation polycondensation under the optimized reaction conditions produces the corresponding π-conjugated polymer with a high molecular weight and terminal octafluorobiphenyl units at both ends.


Asunto(s)
Fluorenos , Polímeros , Catálisis , Polimerizacion , Paladio/química , Hidrocarburos Fluorados/química
2.
Am J Emerg Med ; 78: 182-187, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38301368

RESUMEN

OBJECTIVE: Oxygen consumption (VO2), carbon dioxide generation (VCO2), and respiratory quotient (RQ), which is the ratio of VO2 to VCO2, are critical indicators of human metabolism. To seek a link between the patient's metabolism and pathophysiology of critical illness, we investigated the correlation of these values with mortality in critical care patients. METHODS: This was a prospective, observational study conducted at a suburban, quaternary care teaching hospital. Age 18 years or older healthy volunteers and patients who underwent mechanical ventilation were enrolled. A high-fidelity automation device, which accuracy is equivalent to the gold standard Douglas Bag technique, was used to measure VO2, VCO2, and RQ at a wide range of fraction of inspired oxygen (FIO2). RESULTS: We included a total of 21 subjects including 8 post-cardiothoracic surgery patients, 7 intensive care patients, 3 patients from the emergency room, and 3 healthy volunteers. This study included 10 critical care patients, whose metabolic measurements were performed in the ER and ICU, and 6 died. VO2, VCO2, and RQ of survivors were 282 +/- 95 mL/min, 202 +/- 81 mL/min, and 0.70 +/- 0.10, and those of non-survivors were 240 +/- 87 mL/min, 140 +/- 66 mL/min, and 0.57 +/- 0.08 (p = 0.34, p = 0.10, and p < 0.01), respectively. The difference of RQ was statistically significant (p < 0.01) and it remained significant when the subjects with FIO2 < 0.5 were excluded (p < 0.05). CONCLUSIONS: Low RQ correlated with high mortality, which may potentially indicate a decompensation of the oxygen metabolism in critically ill patients.


Asunto(s)
Pulmón , Respiración Artificial , Humanos , Adolescente , Estudios Prospectivos , Calorimetría Indirecta/métodos , Consumo de Oxígeno , Dióxido de Carbono/metabolismo , Enfermedad Crítica/terapia , Oxígeno
3.
BMC Pulm Med ; 23(1): 390, 2023 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-37840131

RESUMEN

OBJECTIVE: Using a system, which accuracy is equivalent to the gold standard Douglas Bag (DB) technique for measuring oxygen consumption (VO2), carbon dioxide generation (VCO2), and respiratory quotient (RQ), we aimed to continuously measure these metabolic indicators and compare the values between post-cardiothoracic surgery and critical care patients. METHODS: This was a prospective, observational study conducted at a suburban, quaternary care teaching hospital. Age 18 years or older patients who underwent mechanical ventilation were enrolled. RESULTS: We included 4 post-surgery and 6 critical care patients. Of those, 3 critical care patients died. The longest measurement reached to 12 h and 15 min and 50 cycles of repeat measurements were performed. VO2 of the post-surgery patients were 234 ± 14, 262 ± 27, 212 ± 16, and 192 ± 20 mL/min, and those of critical care patients were 122 ± 20, 189 ± 9, 191 ± 7, 191 ± 24, 212 ± 12, and 135 ± 21 mL/min, respectively. The value of VO2 was more variable in the post-surgery patients and the range of each patient was 44, 126, 71, and 67, respectively. SOFA scores were higher in non-survivors and there were negative correlations of RQ with SOFA. CONCLUSIONS: We developed an accurate system that enables continuous and repeat measurements of VO2, VCO2, and RQ. Critical care patients may have less activity in metabolism represented by less variable values of VO2 and VCO2 over time as compared to those of post-cardiothoracic surgery patients. Additionally, an alteration of these values may mean a systemic distinction of the metabolism of critically ill patients.


Asunto(s)
Cuidados Críticos , Consumo de Oxígeno , Humanos , Adolescente , Estudios Prospectivos , Calorimetría Indirecta/métodos , Respiración Artificial , Dióxido de Carbono/metabolismo
4.
Anal Biochem ; 630: 114320, 2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-34343480

RESUMEN

This study aimed to provide a novel and highly sensitive protein assay based on the biuret reaction and using chromeazurol B, a metal chelate compound. The method consists of two reagents and an automated analyzer. First, a complex of copper and protein (biuret reaction) is formed. Second, a chelating reagent containing chromeazurol B forms a three-dimensional complex of protein, copper, and chromeazurol B at neutral pH, resulting in highly sensitive coloration. The intra-assay (n = 20) variation for the three levels was 3.54 % or lower at each concentration. Each response with α, ß-, and γ-globulin was 103.8 % and 104.3 %, respectively, against albumin. The molar absorption coefficient (ε) of the present method was 2.5 × 105 m2/mol against human albumin, higher than that of the commercially available Lowry method (ε = 8.7 × 104 m2/mol), which is based on the same principle. The correlation test for the pyrogallol method with 30 urine samples showed good performance (r = 0.961). The method described here (the Biuret-based CAB method) is a more sensitive and rapid assay than the Lowry method, and it may also be applied to biological samples because of its similar reactivity towards various proteins.


Asunto(s)
Benzoatos/química , Quelantes/química , Cobre/química , Compuestos Organometálicos/química , Quelantes/síntesis química , Globulinas/análisis , Hemoglobinas/análisis , Humanos , Estructura Molecular , Compuestos Organometálicos/síntesis química , Albúmina Sérica Humana/análisis , alfa 1-Antitripsina/análisis , Microglobulina beta-2/análisis
5.
Clin Ther ; 44(11): 1471-1479, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36220676

RESUMEN

PURPOSE: To develop a system that is equivalent to the gold standard Douglas Bag (DB) technique for measuring oxygen consumption (V̇o2), carbon dioxide generation (V̇co2), and respiratory quotient (RQ) and to validate its use in clinical settings. METHODS: This was a prospective, observational study conducted at a suburban, quaternary care teaching hospital. Healthy volunteers and patients 18 years or older who received mechanical ventilation were enrolled. FINDINGS: Data from 3 healthy volunteers and 7 patients were analyzed in this study. The interrater reliability between the automation device and DB methods were 0.999, 0.993, and 0.993 for V̇o2, V̇co2, and RQ, respectively. In healthy volunteers, mean (SD) V̇o2, V̇co2, and RQ measured by DB were 411 (100) mL/min, 288 (79) mL/min, and 0.70 (0.03) at high fraction of inspired oxygen (Fio2) and 323 (46) mL/min, 280 (45) mL/min, and 0.85 (0.05) at normal Fio2, respectively. V̇o2 was significantly higher (P < 0.05) and RQ was lower (P < 0.01) in the high Fio2 group as compared to those in the normal Fio2 group. Values measured by the automation system were 227 (31) mL/min, 141 (18) mL/min, and 0.62 (0.04) at high Fio2 and 209 (25) mL/min, 147 (18) mL/min, and 0.70 (0.06) at normal Fio2, respectively. RQ was significantly lower (P < 0.05) in the high Fio2 group as compared to the normal Fio2 group. We also successfully performed continuous and repeat measurements by using the device. The longest measurement reached 12 hours 15 minutes, including 50 cycles of repeat measurements that are equivalent to the DB technique as described above. IMPLICATIONS: We developed an automation system that enables repeat measurements of V̇o2, V̇co2, and RQ, and the accuracy was equivalent to the DB technique. High Fio2 may decrease RQ because of an increase in V̇o2.


Asunto(s)
Oxígeno , Respiración Artificial , Humanos , Calorimetría Indirecta/métodos , Reproducibilidad de los Resultados , Estudios Prospectivos , Automatización
6.
Nat Commun ; 9(1): 1870, 2018 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-29760386

RESUMEN

Selective modification of native proteins in live cells is one of the central challenges in recent chemical biology. As a unique bioorthogonal approach, ligand-directed chemistry recently emerged, but the slow kinetics limits its scope. Here we successfully overcome this obstacle using N-acyl-N-alkyl sulfonamide as a reactive group. Quantitative kinetic analyses reveal that ligand-directed N-acyl-N-alkyl sulfonamide chemistry allows for rapid modification of a lysine residue proximal to the ligand binding site of a target protein, with a rate constant of ~104 M-1 s-1, comparable to the fastest bioorthogonal chemistry. Despite some off-target reactions, this method can selectively label both intracellular and membrane-bound endogenous proteins. Moreover, the unique reactivity of N-acyl-N-alkyl sulfonamide enables the rational design of a lysine-targeted covalent inhibitor that shows durable suppression of the activity of Hsp90 in cancer cells. This work provides possibilities to extend the covalent inhibition approach that is currently being reassessed in drug discovery.


Asunto(s)
Técnicas de Química Analítica , Proteínas HSP90 de Choque Térmico/química , Lisina/química , Coloración y Etiquetado/métodos , Sulfanilamidas/química , Animales , Línea Celular Tumoral , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Células HeLa , Compuestos Heterocíclicos con 1 Anillo/química , Humanos , Cinética , Ratones , Mioblastos/química , Mioblastos/citología , Mioblastos/efectos de los fármacos , Mioblastos/metabolismo , Sulfanilamidas/farmacología , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/química , Tetrahidrofolato Deshidrogenasa/química
7.
Anticancer Res ; 37(1): 81-85, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-28011477

RESUMEN

BACKGROUND: A long noncoding RNA, p21-associated ncRNA DNA damage-activated (PANDA), associates with nuclear transcription factor Y subunit alpha (NF-YA) and inhibits its binding to promoters of apoptosis-related genes, thereby repressing apoptosis in normal human fibroblasts. Here, we show that PANDA is involved in regulating proliferation in the U2OS human osteosarcoma cell line. MATERIALS AND METHODS: U2OS cells were transfected with siRNAs against PANDA 72 h later and they were subjected to reverse transcription-polymerase chain reaction (RT-PCR), quantitative RT-PCR and cell-cycle analysis. RESULTS: PANDA was highly expressed in U2OS cells, and its expression was induced by DNA damage. Silencing PANDA caused arrest at the G1 phase of the cell cycle, leading to inhibition of cell proliferation. Quantitative RT-PCR showed that silencing PANDA increased mRNA levels of the cyclin-dependent kinase inhibitor p18, which caused G1 phase arrest. CONCLUSION: These results suggest that PANDA promotes G1-S transition by repressing p18 transcription, and thus promotes U2OS cell proliferation.


Asunto(s)
Neoplasias Óseas/metabolismo , Proliferación Celular , Osteosarcoma/metabolismo , ARN Largo no Codificante/metabolismo , Neoplasias Óseas/genética , Neoplasias Óseas/patología , Inhibidor p18 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p18 de las Quinasas Dependientes de la Ciclina/metabolismo , Daño del ADN , Puntos de Control de la Fase G1 del Ciclo Celular , Regulación Neoplásica de la Expresión Génica , Células HeLa , Humanos , Células MCF-7 , Osteosarcoma/genética , Osteosarcoma/patología , Interferencia de ARN , ARN Largo no Codificante/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Factores de Tiempo , Transcripción Genética , Transfección
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