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2.
BMC Cancer ; 24(1): 765, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38926636

RESUMEN

BACKGROUND: It is unclear whether hepatectomy, which ranges in invasiveness from partial to major hepatectomy, is safe and feasible for older adult patients. Therefore, we compared its postoperative complications and long-term outcomes between younger and older adult patients. METHODS: Patients who underwent hepatectomies for hepatocellular carcinoma (N = 883) were evaluated. Patients were divided into two groups: aged < 75 years (N = 593) and ≥ 75 years (N = 290). Short-term outcomes and prognoses were compared between the groups in the entire cohort. The same analyses were performed for the major hepatectomy cohort. RESULTS: In the entire cohort, no significant differences were found in complications between patients aged < 75 and ≥ 75 years, and the multivariate analysis did not reveal age as a prognostic factor for postoperative complications. However, overall survival was significantly worse in older patients, although no significant differences were noted in time to recurrence or cancer-specific survival. In the multivariate analyses of time to recurrence, overall survival, and cancer-specific survival, although older age was an independent poor prognostic factor for overall survival, it was not a prognostic factor for time to recurrence and cancer-specific survival. In the major hepatectomy subgroup, short- and long-term outcomes, including time to recurrence, overall survival, and cancer-specific survival, did not differ significantly between the age groups. In the multivariate analysis, age was not a significant prognostic factor for complications, time to recurrence, overall survival, or cancer-specific survival. CONCLUSION: Hepatectomy, including minor and major hepatectomy, may be safe and oncologically feasible options for selected older adult patients with hepatocellular carcinoma.


Asunto(s)
Carcinoma Hepatocelular , Estudios de Factibilidad , Hepatectomía , Neoplasias Hepáticas , Humanos , Hepatectomía/métodos , Hepatectomía/efectos adversos , Neoplasias Hepáticas/cirugía , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/patología , Carcinoma Hepatocelular/cirugía , Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/patología , Anciano , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Anciano de 80 o más Años , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Pronóstico , Resultado del Tratamiento , Factores de Edad , Recurrencia Local de Neoplasia/cirugía , Adulto
3.
J Nat Prod ; 86(4): 1087-1119, 2023 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-36848595

RESUMEN

Flavonoids play diverse roles in plants, comprise a non-negligible fraction of net primary photosynthetic production, and impart beneficial effects in human health from a plant-based diet. Absorption spectroscopy is an essential tool for quantitation of flavonoids isolated from complex plant extracts. The absorption spectra of flavonoids typically consist of two major bands, band I (300-380 nm) and band II (240-295 nm), where the former engenders a yellow color; in some flavonoids the absorption tails to 400-450 nm. The absorption spectra of 177 flavonoids and analogues of natural or synthetic origin have been assembled, including molar absorption coefficients (109 from the literature, 68 measured here). The spectral data are in digital form and can be viewed and accessed at http://www.photochemcad.com. The database enables comparison of the absorption spectral features of 12 distinct types of flavonoids including flavan-3-ols (e.g., catechin, epigallocatechin), flavanones (e.g., hesperidin, naringin), 3-hydroxyflavanones (e.g., taxifolin, silybin), isoflavones (e.g., daidzein, genistein), flavones (e.g., diosmin, luteolin), and flavonols (e.g., fisetin, myricetin). The structural features that give rise to shifts in wavelength and intensity are delineated. The availability of digital absorption spectra for diverse flavonoids facilitates analysis and quantitation of these valuable plant secondary metabolites. Four examples are provided of calculations─multicomponent analysis, solar ultraviolet photoprotection, sun protection factor (SPF), and Förster resonance energy transfer (FRET)─for which the spectra and accompanying molar absorption coefficients are sine qua non.


Asunto(s)
Flavonas , Flavonoides , Humanos , Flavonoides/química , Plantas/química , Genisteína
4.
Planta Med ; 89(7): 746-753, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36796450

RESUMEN

The present study investigates the effects of acertannin on colitis induced by dextran sulfate sodium (DSS) and changes in the colonic levels of the cytokines interleukin (IL)-1ß, IL-6, IL-10, IL-23, tumor necrosis factor (TNF)-α, the chemokine monocyte chemoattractant protein (MCP)-1, and vascular endothelial growth factor (VEGF).We examine the following: inflammatory colitis was induced in mice by 2% DSS drinking water given ad libitum for 7 days. Red blood cell, platelets, and leukocyte counts and hematocrit (Ht), hemoglobin (Hb), and colonic cytokine and chemokine levels were measured. The disease activity index (DAI) was lower in DSS-treated mice orally administered acertannin (30 and 100 mg/kg) than in DSS-treated mice. Acertannin (100 mg/kg) inhibited reductions in the red blood cell count and Hb and Ht levels in DSS-treated mice. Acertannin prevented DDS-induced mucosal membrane ulceration of the colon and significantly inhibited the increased colonic levels of IL-23 and TNF-α. Our findings suggest that acertannin has potential as a treatment for inflammatory bowel disease (IBD).


Asunto(s)
Colitis , Factor de Necrosis Tumoral alfa , Ratones , Animales , Factor de Necrosis Tumoral alfa/metabolismo , Sulfato de Dextran/efectos adversos , Interleucina-23/efectos adversos , Interleucina-23/metabolismo , Ratones Endogámicos C57BL , Factor A de Crecimiento Endotelial Vascular/efectos adversos , Factor A de Crecimiento Endotelial Vascular/metabolismo , Colitis/inducido químicamente , Colitis/tratamiento farmacológico , Colon/patología , Citocinas/metabolismo , Modelos Animales de Enfermedad
5.
Planta Med ; 89(6): 637-662, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36198325

RESUMEN

Phyllobilins are open-chain products of the biological degradation of chlorophyll a in higher plants. Recent studies reveal that phyllobilins exert anti-oxidative and anti-inflammatory properties, as well as activities against cancer cells, that contribute to the human health benefits of numerous plants. In general, phyllobilins have been overlooked in phytochemical analyses, and - more importantly - in the analyses of medicinal plant extracts. Nevertheless, over the past three decades, > 70 phyllobilins have been identified upon examination of more than 30 plant species. Eight distinct chromophoric classes of phyllobilins are known: phyllolumibilins (PluBs), phylloleucobilins (PleBs), phylloxanthobilins (PxBs), and phylloroseobilins (PrBs)-each in type-I or type-II groups. Here, we present a database of absorption and fluorescence spectra that has been compiled of 73 phyllobilins to facilitate identification in phytochemical analyses. The spectra are provided in digital form and can be viewed and downloaded at www.photochemcad.com. The present review describes the plant origin, molecular structure, and absorption and fluorescence features of the 73 phyllobilins, along with an overview of key medicinal properties. The review should provide an enabling tool for the community for the straightforward identification of phyllobilins in plant extracts, and the foundation for deeper understanding of these ubiquitous but underexamined plant-derived micronutrients for human health.


Asunto(s)
Clorofila , Plantas , Humanos , Clorofila/análisis , Clorofila/química , Clorofila/metabolismo , Clorofila A/metabolismo , Plantas/metabolismo , Oxidación-Reducción , Extractos Vegetales/química , Fitoquímicos/química
6.
World J Surg Oncol ; 21(1): 268, 2023 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-37626381

RESUMEN

BACKGROUND: Frailty has been globally recognized as a predictor of adverse postoperative outcomes. Frailty assessment using the five-factor modified frailty index (5-mFI) has recently gained traction; however, long-term outcomes are unknown in colorectal cancer (CRC) surgery. This study aimed to investigate whether the 5-mFI predicted long-term survival and cause of death on the basis of frailty severity in elderly patients who underwent CRC surgery and to determine the risk factors for mortality. METHODS: A total of 299 patients underwent CRC surgery with curative intent between January 2013 and December 2017. Patients were divided into three groups by the 5-mFI score: group 1 (5-mFI: 0 or 1; n = 164): no frailty; group 2 (5-mFI: 2; n = 91): moderate frailty; and group 3 (5-mFI: ≥ 3; n = 44): severe frailty. Clinicopathological variables, namely comorbidities, 5-mFI, prognostic nutrition index, operative/postoperative data, and outcome, including cause of death, were compared between the three groups. To identify factors associated with death from CRC- and non-CRC-related causes, univariate and multivariate analyses using a Cox regression model were performed. RESULTS: The immediate postoperative morbidity of patients with Clavien-Dindo grade ≥ III complications (9.1%) in group 3 was not significantly different from that in group 1 (9.1%) or group 2 (14.3%); however, the 30-day mortality rate (4.5%) in group 3 was significantly higher. Long-term disease-free survival was similar between frailty groups, suggesting that CRC surgery provides oncological benefit to patients irrespective of frailty. The 5-year survival rates in groups 1, 2, and 3 were 83.5%, 71.2%, and 47.9%, respectively, showing a significantly lower survival rate as frailty advanced. Sixty percent of the deaths in frail patients were due to respiratory failure and cardiovascular diseases. Multivariate analysis demonstrated that advanced age, higher 5-mFI score, and longer postoperative hospital stay were risk factors for mortality unrelated to CRC. Multivariate analysis also revealed that advanced tumor stage, carcinoembryonic antigen ≥ 5 ng/ml, undifferentiated tumor, and R1 resection were risk factors for CRC-related mortality. CONCLUSIONS: The 5-mFI score can predict postoperative short- and long-term outcomes and risk factors for mortality unrelated to CRC. Additionally, long-term survival was negatively associated with the 5-mFI score.


Asunto(s)
Enfermedades Cardiovasculares , Neoplasias Colorrectales , Procedimientos Quirúrgicos del Sistema Digestivo , Anciano , Humanos , Supervivencia sin Enfermedad , Tiempo de Internación , Neoplasias Colorrectales/cirugía
7.
J Artif Organs ; 2023 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-38051434

RESUMEN

Presepsin, which is used as a biomarker for sepsis, is thought to be removed by dialysis, but the actual removal properties of dialysis are unknown. We investigated the presepsin removal properties of continuous hemodiafiltration using the high concentration of presepsin from human plasma drained by plasma exchange. Each solution in plasma exchange was connected to a continuous hemodiafiltration blood circuit and circulated at 4 conditions. The results show that presepsin was confirmed to be removed more efficiently in hemofiltration than in hemodialysis. In addition, when using a polymethylmethacrylate hemofilter for continuous hemodiafiltration, the lowest presepsin concentration is on the filtrate side, suggesting that the main removal mechanism is adsorption. Since presepsin has a molecular weight of 13,000, its removal efficiency is high by hemofiltration as per principle. In addition, since the main adsorption principle of polymethylmethacrylate hemofilter is hydrophobic bond, presepsin is considered to be adsorbed. Since presepsin is metabolized in the kidney, it is elevated in renal failure. In this paper, we confirmed that presepsin is eliminated by continuous hemodiafiltration not only in the kidney. Depending on the timing of presepsin measurement, there is a risk of missing the diagnosis of sepsis. Kidney function and continuous hemodiafiltration should be checked when measuring presepsin.

8.
Molecules ; 28(3)2023 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-36770988

RESUMEN

The photosynthetic tetrapyrroles share a common structural feature comprised of a ß-ketoester motif embedded in an exocyclic ring (ring E). As part of a total synthesis program aimed at preparing native structures and analogues, 3-(3-methoxy-1,3-dioxopropyl)pyrrole was sought. The pyrrole is a precursor to analogues of ring C and the external framework of ring E. Four routes were developed. Routes 1-3 entail a Pd-mediated coupling process of a 3-iodopyrrole with potassium methyl malonate, whereas route 4 relies on electrophilic substitution of TIPS-pyrrole with methyl malonyl chloride. Together, the four routes afford considerable latitude. A long-term objective is to gain the capacity to create chlorophylls and bacteriochlorophylls and analogues thereof by facile de novo means for diverse studies across the photosynthetic sciences.


Asunto(s)
Pirroles , Tetrapirroles , Pirroles/química , Clorofila/química , Bacterioclorofilas/química , Fotosíntesis
9.
Molecules ; 28(16)2023 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-37630384

RESUMEN

Tolyporphins were discovered some 30 years ago as part of a global search for antineoplastic compounds from cyanobacteria. To date, the culture HT-58-2, comprised of a cyanobacterium-microbial consortium, is the sole known producer of tolyporphins. Eighteen tolyporphins are now known-each is a free base tetrapyrrole macrocycle with a dioxobacteriochlorin (14), oxochlorin (3), or porphyrin (1) chromophore. Each compound displays two, three, or four open ß-pyrrole positions and two, one, or zero appended C-glycoside (or -OH or -OAc) groups, respectively; the appended groups form part of a geminal disubstitution motif flanking the oxo moiety in the pyrroline ring. The distinct structures and repertoire of tolyporphins stand alone in the large pigments-of-life family. Efforts to understand the cyanobacterial origin, biosynthetic pathways, structural diversity, physiological roles, and potential pharmacological properties of tolyporphins have attracted a broad spectrum of researchers from diverse scientific areas. The identification of putative biosynthetic gene clusters in the HT-58-2 cyanobacterial genome and accompanying studies suggest a new biosynthetic paradigm in the tetrapyrrole arena. The present review provides a comprehensive treatment of the rich science concerning tolyporphins.


Asunto(s)
Glicósidos Cardíacos , Cianobacterias , Porfirinas , Tetrapirroles , Cianobacterias/genética , Porfirinas/farmacología
10.
Nat Immunol ; 11(7): 594-600, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20512151

RESUMEN

The recirculation of leukocytes is essential for proper immune responses. However, the molecular mechanisms that regulate the entry of leukocytes into the lymphatics remain unclear. Here we show that plexin-A1, a principal receptor component for class III and class VI semaphorins, was crucially involved in the entry of dendritic cells (DCs) into the lymphatics. Additionally, we show that the semaphorin Sema3A, but not Sema6C or Sema6D, was required for DC transmigration and that Sema3A produced by the lymphatics promoted actomyosin contraction at the trailing edge of migrating DCs. Our findings not only demonstrate that semaphorin signals are involved in DC trafficking but also identify a previously unknown mechanism that induces actomyosin contraction as these cells pass through narrow gaps.


Asunto(s)
Células Dendríticas/metabolismo , Vasos Linfáticos/metabolismo , Miosina Tipo II/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Receptores de Superficie Celular/metabolismo , Semaforinas/metabolismo , Actomiosina/metabolismo , Traslado Adoptivo , Animales , Ensayos de Migración de Leucocitos , Movimiento Celular/inmunología , Células Cultivadas , Células Dendríticas/inmunología , Células Dendríticas/patología , Técnicas de Sustitución del Gen , Inmunidad , Vasos Linfáticos/patología , Ratones , Ratones Noqueados , Contracción Muscular , Miosina Tipo II/inmunología , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/inmunología , Neuropilina-1/genética , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/inmunología , Semaforinas/genética , Semaforinas/inmunología , Transducción de Señal
11.
J Phys Chem A ; 126(50): 9353-9365, 2022 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-36508586

RESUMEN

A panchromatic triad and a charge-separation unit are joined in a crossbar architecture to capture solar energy. The panchromatic-absorber triad (T) is comprised of a central free-base porphyrin that is strongly coupled via direct ethyne linkages to two perylene-monoimide (PMI) groups. The charge-separation unit incorporates a free-base or zinc chlorin (C or ZnC) as a hole acceptor (or electron donor) and a perylene-diimide (PDI) as an electron acceptor, both attached to the porphyrin via diphenylethyne linkers. The free-base porphyrin is common to both light-harvesting and charge-separation motifs. The chlorin and PDI also function as ancillary light absorbers, complementing direct excitation of the panchromatic triad to produce the discrete lowest excited state of the array (T*). Attainment of full charge separation across the pentad entails two steps: (1) an initial excited-state hole/electron-transfer process to oxidize the chlorin (and reduce the panchromatic triad) or reduce the PDI (and oxidize the panchromatic triad); and (2) subsequent ground-state electron/hole migration to produce oxidized chlorin and reduced PDI. Full charge separation for pentad ZnC-T-PDI to generate ZnC+-T-PDI- occurs with a quantum yield of ∼30% and mean lifetime ∼1 µs in dimethyl sulfoxide. For C-T-PDI, initial charge separation is followed by rapid charge recombination. The molecular designs and studies reported here reveal the challenges of balancing the demands for charge separation (linker length and composition, excited-state energies, redox potentials, and medium polarity) with the constraints for panchromatic absorption (strong electronic coupling of the porphyrin and two PMI units) for integrated function in solar-energy conversion.


Asunto(s)
Perileno , Porfirinas , Transporte de Electrón , Imidas
12.
Molecules ; 27(19)2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-36235037

RESUMEN

The syntheses of two triads are reported. Each triad is composed of two perylene-monoimides linked to a porphyrin via an ethyne unit, which bridges the perylene 9-position and a porphyrin 5- or 15-position. Each triad also contains a single tether composed of an alkynoic acid or an isophthalate unit. Each triad provides panchromatic absorption (350-700 nm) with fluorescence emission in the near-infrared region (733 or 743 nm; fluorescence quantum yield ~0.2). The syntheses rely on the preparation of trans-AB-porphyrins bearing one site for tether attachment (A), an aryl group (B), and two open meso-positions. The AB-porphyrins were prepared by the condensation of a 1,9-diformyldipyrromethane and a dipyrromethane. The installation of the two perylene-monoimide groups was achieved upon the 5,15-dibromination of the porphyrin and the subsequent copper-free Sonogashira coupling, which was accomplished before or after the attachment of the tether. The syntheses provide relatively straightforward access to a panchromatic absorber for use in bioconjugation or surface-attachment processes.


Asunto(s)
Perileno , Porfirinas
13.
Phys Chem Chem Phys ; 23(35): 19130-19140, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34490865

RESUMEN

Tetrapyrrole macrocycles serve a multitude of roles in biological systems, including oxygen transport by heme and light harvesting and charge separation by chlorophylls and bacteriochlorophylls. Synthetic tetrapyrroles are utilized in diverse applications ranging from solar-energy conversion to photomedicine. Nevertheless, students beginning tetrapyrrole research, as well as established practitioners, are often puzzled when comparing properties of related tetrapyrroles. Questions arise as to why optical spectra of two tetrapyrroles often shift in wavelength/energy in a direction opposite to that predicted by common chemical intuition based on the size of a π-electron system. Gouterman's four-orbital model provides a framework for understanding these optical properties. Similarly, it can be puzzling as to why the oxidation potentials differ significantly when comparing two related tetrapyrroles, yet the reduction potentials change very little or shift in the opposite direction. In order to understand these redox properties, it must be recognized that structural/electronic alterations affect the four frontier molecular orbitals (HOMO, LUMO, HOMO-1 and LUMO+1) unequally and in many cases the LUMO+1, and not the LUMO, may track the HOMO in energy. This perspective presents a fundamental framework concerning tetrapyrrole electronic properties that should provide a foundation for rational molecular design in tetrapyrrole science.


Asunto(s)
Tetrapirroles/química , Bacterioclorofilas/química , Clorofila/química , Teoría Funcional de la Densidad , Electrones , Oxidación-Reducción , Porfirinas/química , Teoría Cuántica
14.
J Phys Chem A ; 125(36): 7900-7919, 2021 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-34472866

RESUMEN

Panchromatic absorbers have potential applications in molecular-based energy-conversion schemes. A prior porphyrin-perylene dyad (P-PMI, where "MI" denotes monoimide) coupled via an ethyne linker exhibits panchromatic absorption (350-700 nm) and a tetrapyrrole-like lowest singlet excited state with a relatively long singlet excited-state lifetime (τS) and increased fluorescence quantum yield (Φf) versus the parent porphyrin. To explore the extension of panchromaticity to longer wavelengths, three arrays have been synthesized: a chlorin-terrylene dyad (C-TMI), a bacteriochlorin-terrylene dyad (B-TMI), and a perylene-porphyrin-terrylene triad (PMI-P-TMI), where the terrylene, a π-extended homologue of perylene, is attached via an ethyne linker. Characterization of the spectra (absorption and fluorescence), excited-state properties (lifetime, yields, and rate constants of decay pathways), and molecular-orbital characteristics reveals unexpected subtleties. The wavelength of the red-region absorption band increases in the order C-TMI (705 nm) < PMI-P-TMI (749 nm) < B-TMI (774 nm), yet each array exhibits diminished Φf and shortened τS values. The PMI-P-TMI triad in toluene exhibits Φf = 0.038 and τS = 139 ps versus the all-perylene triad (PMI-P-PMI) for which Φf = 0.26 and τS = 2000 ps. The results highlight design constraints for auxiliary pigments with tetrapyrroles to achieve panchromatic absorption with retention of viable excited-state properties.

15.
J Phys Chem A ; 124(38): 7776-7794, 2020 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-32926787

RESUMEN

Six zinc(II) porphyrins bearing 0-4 meso-phenyl substituents have been examined spectroscopically and theoretically. Comparisons with previously examined free base analogues afford a deep understanding of the electronic and photophysical effects of systematic addition of phenyl groups in porphyrins containing a central zinc(II) ion versus two hydrogen atoms. Trends in the wavelengths and relative intensities of the absorption bands are generally consistent with predictions from time-dependent density functional theory calculations and simulations from Gouterman's four-orbital model. These trends derive from a preferential effect of the meso-phenyl groups to raise the energy of the highest occupied molecular orbital. The calculations reveal additional insights, such as a progressive increase in oscillator strength in the violet-red (B-Q) absorption manifold with increasing number of phenyls. Progressive addition of 0-4 phenyl substituents to the zinc porphyrins in O2-free toluene engenders a reduction in the measured lifetime of the lowest singlet excited state (2.5-2.1 ns), an increase in the S1 → S0 fluorescence yield (0.022-0.030), a decrease in the yield of S1 → T1 intersystem crossing (0.93-0.88), and an increase in the yield of S1 → S0 internal conversion (0.048-0.090). The derived rate constants for S1 decay reveal significant differences in the photophysical properties of the zinc chelates versus free base forms. The unexpected finding of a larger rate constant for internal conversion for zinc chelates versus free bases is particularly exemplary. Collectively, the findings afford fundamental insights into the photophysical properties and electronic structure of meso-phenylporphyrins, which are widely used as benchmarks for tetrapyrrole-based architectures in solar energy and life sciences research.

16.
BMC Med Educ ; 20(1): 329, 2020 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-32972399

RESUMEN

BACKGROUND: Effective education about endoscopic surgery (ES) is greatly needed for unskilled surgeons, especially at low-volume institutions, to maintain the safety of patients. We have tried to establish the remote educational system using videoconference system through the internet for education about ES to surgeons belonging to affiliate institutions. The aim of this manuscript was to report the potential to establish a comfortable remote educational system and to debate its advantages. METHODS: We established a local remote educational conference system by combining the use of a general web conferencing system and a synchronized remote video playback system with annotation function through a high-speed internet. RESULTS: During 2014-2019, we conducted 14 videoconferences to review and improve surgeons' skills in performing ES at affiliated institutions. At these conferences, while an uncut video of ES that had been performed at one of the affiliated institutions was shown, the surgical procedure was discussed frankly, and expert surgeons advised improvements. The annotation system is useful for easy, prompt recognition among the audience regarding anatomical structures and procedures that are difficult to explain verbally. CONCLUSIONS: This system is of low initial cost and offers easy participation and high-quality videos. It would therefore be a useful tool for regional ES education.


Asunto(s)
Telecomunicaciones , Endoscopía , Humanos , Internet , Grabación en Video , Comunicación por Videoconferencia
17.
J Chem Inf Model ; 59(2): 652-667, 2019 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-30715870

RESUMEN

Among the photophysical parameters that underpin Förster resonance energy transfer (FRET), perhaps the least explored is the spectral overlap term ( J). While by definition J increases linearly with acceptor molar absorption coefficient (ε(A) in M-1 cm-1), is proportional to wavelength (λ4), and depends on the degree of overlap of the donor fluorescence and acceptor absorption spectra, the question arose as to the value of J for the case of perfect spectral overlap versus that for representative fluorophores with incomplete spectral overlap. Here, Gaussian distributions of absorption and fluorescent spectra have been modeled that encompass varying degrees of overlap, full-width-at-half-maximum (fwhm), and Stokes shift. For ε(A) = 105 M-1 cm-1 and perfect overlap, the J value (in M-1 cm-1 nm4) ranges from 1.15 × 1014 (200 nm) to 7.07 × 1016 (1000 nm), is almost linear with λ4 (average of λabs and λflu), and is nearly independent of fwhm. For visible-region fluorophores with perfectly overlapped Gaussian spectra, the resulting value of J ( JG-0) is ∼0.71 ε(A)λ4 (M-1 cm-1 nm4). The experimental J values for homotransfer, as occurs in light-harvesting antennas, were calculated with spectra from a static database of 60 representative compounds (12 groups, 5 compounds each) and found to range from 4.2 × 1010 ( o-xylene) to 5.3 × 1016 M-1 cm-1 nm4 (a naphthalocyanine). The degree of overlap, defined by the ratio of the experimental J to the model JG-0 for perfectly overlapped spectra, ranges from ∼0.5% (coumarin 151) to 77% (bacteriochlorophyll a). The results provide insights into how a variety of factors affect the resulting J values. The high degree of spectral overlap for (bacterio)chlorophylls prompts brief conjecture concerning the relevance of energy transfer to the question "why chlorophyll".


Asunto(s)
Transferencia Resonante de Energía de Fluorescencia , Heurística , Modelos Teóricos , Absorción Fisicoquímica , Distribución Normal
18.
Chem Rev ; 117(2): 344-535, 2017 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-27498781

RESUMEN

Chlorophylls make Earth green, are the central constituents in the engine of photosynthesis, and not surprisingly have garnered immense attention. A chlorin, the core chromophore of a chlorophyll, is a dihydroporphyrin macrocycle that contains one pyrroline ring and three pyrrole rings. The dominant method for the synthesis of chlorins has entailed the derivatization of porphyrins. The present review covers the ostensibly simple conversion of porphyrins, regardless of synthetic or biological origin, to chlorins. The period covered encompasses the entire history since the beginnings of chlorin synthetic chemistry in the early 20th century through 2015. Representative transformations include hydrogenation, cycloaddition, annulation, and diverse "breaking and mending" approaches. Altogether, the synthesis of >1000 chlorins or chlorin-like compounds (containing >50 distinct pyrroline motifs) is described. Such diversity animates the question "what structural features are essential for a chlorin to resemble chlorophyll?" To begin to address the structure-spectrum relationship, > 250 absorption spectra are provided for representative structures. The synthesis and spectral properties of the vast collection of compounds described herein are expected to illuminate the scope to which synthetic chlorins can serve as surrogates for chlorophylls and be exploited in diverse ways.


Asunto(s)
Clorofila/química , Porfirinas/química , Estereoisomerismo
19.
World J Surg Oncol ; 17(1): 191, 2019 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-31711502

RESUMEN

BACKGROUND: Biliary intraepithelial neoplasia (BilIN) is often distinguished by what it is not: the precancerous lesions are not mass-forming, are not the cause of bile duct obstruction, and are small enough (less than 5 mm long) to evade detection by the naked eye. Here, we describe an atypical case of BilIN resembling cholangiocarcinoma (CC) that was large enough to be identified by diagnostic imaging and presented with obstructive jaundice caused by a hematoma in the common bile duct (CBD). CASE PRESENTATION: A 64-year-old man presented to our hospital with upper abdominal pain and anorexia. Initial laboratory examinations revealed increased total bilirubin and a computed tomography (CT) scan revealed a dilated CBD. Gastroenterologists performed an endoscopic sphincterotomy (EST), which revealed that the cause of obstructive jaundice was a hematoma in the CBD. Enhanced CT scan and magnetic resonance cholangiopancreatography (MRCP) performed after the hematoma was drained showed improved dilation of the CBD and an enhanced wall thickness of bile duct measuring 25 × 10 mm at the union of the cystic and common hepatic ducts. A cholangioscope detected an elevated tumor covered by sludge in the CBD, and we performed an extrahepatic bile duct resection and cholecystectomy. The postoperative course was uneventful and the pathological examination of the resected tumor revealed that although the ulcerated lesion had inflammatory granulation tissue, it did not contain the components of invasive carcinoma. Many consecutive intraepithelial micropapillary lesions spread around the ulcerated lesion, and the epithelial cells showed an increased nucleus-to-cytoplasm ratio, nuclear hyperchromasia, and architectural atypia. The pathological diagnosis was BilIN-1 to -2. Immunohistochemical staining showed that S100P was slightly expressed and MUC5AC was positive, while MUC1 was negative and p53 was not overexpressed. CONCLUSION: We experienced an atypical case of BilIN mimicking CC that presented with obstructive jaundice caused by a hematoma in the CBD. Our case suggested that the occurrence of BilIN can be triggered by factors other than inflammation, and can grow to a size large enough to be detected by image analyses.


Asunto(s)
Dolor Abdominal/etiología , Conducto Colédoco/patología , Epitelio/patología , Hematoma/etiología , Ictericia Obstructiva/etiología , Anciano , Neoplasias de los Conductos Biliares/diagnóstico , Colangiocarcinoma/diagnóstico , Pancreatocolangiografía por Resonancia Magnética , Colecistectomía , Conducto Colédoco/diagnóstico por imagen , Conducto Colédoco/cirugía , Diagnóstico Diferencial , Humanos , Ictericia Obstructiva/cirugía , Masculino , Pronóstico , Esfinterotomía Endoscópica , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
20.
J Neurosci ; 37(30): 7125-7139, 2017 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-28637841

RESUMEN

Leukocyte common antigen-related (LAR) class protein tyrosine phosphatases (PTPs) are critical for axonal guidance; however, their relation to specific guidance cues is poorly defined. We here show that PTP-3, a LAR homolog in Caenorhabditis elegans, is involved in axon guidance regulated by Semaphorin-2A-signaling. PTPδ, one of the vertebrate LAR class PTPs, participates in the Semaphorin-3A (Sema3A)-induced growth cone collapse response of primary cultured dorsal root ganglion neurons from Mus musculus embryos. In vivo, however, the contribution of PTPδ in Sema3A-regualted axon guidance was minimal. Instead, PTPδ played a major role in Sema3A-dependent cortical dendritic growth. Ptpδ-/- and Sema3a-/- mutant mice exhibited poor arborization of basal dendrites of cortical layer V neurons. This phenotype was observed in both male and female mutants. The double-heterozygous mutants, Ptpδ+/-; Sema3a+/-, also showed a similar phenotype, indicating the genetic interaction. In Ptpδ-/- brains, Fyn and Src kinases were hyperphosphorylated at their C-terminal Tyr527 residues. Sema3A-stimulation induced dephosphorylation of Tyr527 in the dendrites of wild-type cortical neurons but not of Ptpδ-/- Arborization of cortical basal dendrites was reduced in Fyn-/- as well as in Ptpδ+/-; Fyn+/- double-heterozygous mutants. Collectively, PTPδ mediates Sema3A-signaling through the activation of Fyn by C-terminal dephosphorylation.SIGNIFICANCE STATEMENT The relation of leukocyte common antigen-related (LAR) class protein tyrosine phosphatases (PTPs) and specific axon guidance cues is poorly defined. We show that PTP-3, a LAR homolog in Caenorhabditis elegans, participates in Sema2A-regulated axon guidance. PTPδ, a member of vertebrate LAR class PTPs, is involved in Sema3A-regulated cortical dendritic growth. In Sema3A signaling, PTPδ activates Fyn and Src kinases by dephosphorylating their C-terminal Tyr residues. This is the first evidence showing that LAR class PTPs participate in Semaphorin signaling in vivo.


Asunto(s)
Corteza Cerebral/fisiología , Dendritas/fisiología , Plasticidad Neuronal/fisiología , Proteínas Proto-Oncogénicas c-fyn/metabolismo , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/metabolismo , Semaforina-3A/metabolismo , Animales , Células Cultivadas , Corteza Cerebral/ultraestructura , Dendritas/ultraestructura , Activación Enzimática , Femenino , Regulación Enzimológica de la Expresión Génica/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Proteínas Tirosina Quinasas/metabolismo
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