Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
Add more filters










Publication year range
1.
J Thorac Oncol ; 18(12): 1672-1688, 2023 12.
Article in English | MEDLINE | ID: mdl-37689390

ABSTRACT

INTRODUCTION: A lymph node map is the pillar on which accurate assignment and documentation of nodal classification stands. The International Thymic Malignancy Interest Group created the first map for thymic epithelial malignancies in conjunction with the eighth edition of the TNM classification, representing the first official TNM classification of thymic epithelial malignancies. The map was based on clinical experience and published studies, but it was largely empirical because of limited available data. Dissemination of the map and implementation of a standard thymic stage classification across the world in 2017 have provided more consistent and granular data. METHODS: More than twice as many cases of node involvement are available for analysis in the current database compared with that of the eighth edition database, allowing validation of many aspects of the eighth edition map. This article details the process and considerations for refinement of the thymic map for the ninth TNM used by the Thymic Domain of the Staging and Prognostic Factors Committee of the International Association for the Study of Lung Cancer. The committee evaluated a large international collaborative data set, published anatomical and clinical studies pertaining to lymph node spread from thymic epithelial tumors, in conjunction with the analysis underlying refinements of the TNM components for the ninth edition TNM classification. RESULTS: The node map boundaries of the N1 and N2 categories remain unchanged. Visual clarifications have been added to the nomenclature of nodal stations within these regions. CONCLUSIONS: On the basis of the recommendation to keep the N component unchanged for the ninth edition TNM classification, the lymph node map remains unchanged as well; however, clarifications have been added to facilitate clinical use.


Subject(s)
Lung Neoplasms , Neoplasms, Glandular and Epithelial , Thymus Neoplasms , Humans , Neoplasm Staging , Lung Neoplasms/pathology , Public Opinion , Thymus Neoplasms/pathology , Neoplasms, Glandular and Epithelial/pathology , Prognosis , Lymph Nodes/pathology
2.
Nanomicro Lett ; 14(1): 49, 2022 Jan 25.
Article in English | MEDLINE | ID: mdl-35076794

ABSTRACT

Active electronics are usually composed of semiconductor and metal electrodes which are connected by multiple vacuum deposition steps and photolithography patterning. However, the presence of interface of dissimilar material between semiconductor and metal electrode makes various problems in electrical contacts and mechanical failure. The ideal electronics should not have defective interfaces of dissimilar materials. In this study, we developed a novel method to fabricate active electronic components in a monolithic seamless fashion where both metal and semiconductor can be prepared from the same monolith material without creating a semiconductor-metal interface by reversible selective laser-induced redox (rSLIR) method. Furthermore, rSLIR can control the oxidation state of transition metal (Cu) to yield semiconductors with two different bandgap states (Cu2O and CuO with bandgaps of 2.1 and 1.2 eV, respectively), which may allow multifunctional sensors with multiple bandgaps from the same materials. This novel method enables the seamless integration of single-phase Cu, Cu2O, and CuO, simultaneously while allowing reversible, selective conversion between oxidation states by simply shining laser light. Moreover, we fabricated a flexible monolithic metal-semiconductor-metal multispectral photodetector that can detect multiple wavelengths. The unique monolithic characteristics of rSLIR process can provide next-generation electronics fabrication method overcoming the limitation of conventional photolithography methods.

3.
Nanoscale ; 13(30): 13129-13141, 2021 Aug 14.
Article in English | MEDLINE | ID: mdl-34477796

ABSTRACT

Silver nanowire (Ag NW) networks have great potential to replace commercial transparent conducting oxides due to their superior properties in conjunction with their competitive cost, availability and mechanical flexibility. However, there are still challenges to overcome for the large scale utilization of Ag NWs in devices due to oxidation/sulfidation of NWs, which leads to performance loss. Here, we develop a solution-based strategy to deposit a thin platinum (Pt) shell layer (15 nm) onto Ag NWs to improve their chemical, environmental and electrochemical stabilities. Environmental and thermal stabilities of the core-shell NW networks were monitored under different relative humidity conditions (RH of 43, 75 and 85%) and temperature settings (75 °C for 120 hours and 150 °C for 40 hours) and compared to those of bare Ag NWs. Afterwards, stability of core-shell NW networks in hydrogen peroxide was investigated and compared to that of bare Ag NW networks. The potential window for electrochemical stability of the Ag NW networks was broadened to 0-1 V (vs. Ag/AgCl) upon Pt deposition, while bare Ag NWs were stable only in the 0-0.6 V range. Moreover, Ag-Pt core-shell NWs were used for the detection of hydrogen peroxide, where a high sensitivity of 0.04 µA µM-1 over a wide linear range of concentrations (16.6-990.1 µM) with a low detection limit (10.95 µM) was obtained for the fabricated sensors. All in all, this highly effective and simple strategy to improve the stability of Ag NWs will certainly open new avenues for their large-scale utilization in various electrochemical and sensing devices.

4.
Nanoscale ; 11(43): 20356-20378, 2019 Nov 21.
Article in English | MEDLINE | ID: mdl-31403636

ABSTRACT

Research on sustainable and high-efficiency energy devices has recently emerged as an important global issue. These devices are now moving beyond the form of a bulk, rigid platform to a portable, flexible/stretchable format that is easily available in our daily lives. Similar to the development of an active layer for the production of next-generation energy devices, the fabrication of flexible/stretchable electrodes for the easy flow of electrons is also very important. Silver nanowire electrodes have high electronic conductivity even in a flexible/stretchable state due to their high aspect ratio and percolation network structures compared to conventional electrodes. Herein, we summarize the research in the field of flexible/stretchable electronics on energy devices fabricated using silver nanowires as the electrodes. Additionally, for a systematic presentation of the current research trends, this review classifies the surveyed research efforts into the categories of energy production, storage, and consumption.

5.
ACS Appl Mater Interfaces ; 11(17): 15773-15780, 2019 May 01.
Article in English | MEDLINE | ID: mdl-30990648

ABSTRACT

Flexible micro/nano metal grid transparent conductors emerged as an alternative to the fragile/rigid indium tin oxide electrode. They are usually fabricated by the combination of the conventional photolithography and the vacuum deposition of regular metal grid patterns, however, seriously suffer from moiré and starburst problems induced by periodic regular pattern structures. In this paper, we demonstrated flexible and imperceptible random copper microconductors with an extremely high figure-of-merit (∼2000) by the thermal conduction layer-assisted photonic sintering of copper nanoparticles without damages in the plastic substrate. This process can be easily applied to complicated structures and surfaces including a random pattern which is imperceptible and free of interferences. As a proof-of-concept, a transparent windshield defogger in a car was demonstrated with a Cu transparent random conductor at an extreme and reversible fogging state.

6.
Nanotechnology ; 30(7): 074001, 2019 Feb 15.
Article in English | MEDLINE | ID: mdl-30523977

ABSTRACT

Copper nanowires (Cu NWs) are suitable material as an electrode for flexible, stretchable and wearable devices due to their excellent mechanical properties, high transparency, good conductivity, and low cost, but oxidation problem limits their practical use and application. In order to use Cu NWs as an electrode for advanced flexible, stretchable and wearable devices attached directly to the skin, the influence of the body temperature on the oxidation of Cu NWs needs to be investigated. In this paper, the oxidation behavior of Cu NWs at high temperature (more than 80 °C) as well as body temperature is studied which has been remained largely questionable to date, and an effective encapsulation method is proposed to prevent the oxidation of Cu NWs electrode in the range of body temperatures.


Subject(s)
Copper/chemistry , Nanowires/chemistry , Electrodes , Hot Temperature , Oxidation-Reduction , Wearable Electronic Devices
7.
Korean J Physiol Pharmacol ; 21(2): 259-265, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28280420

ABSTRACT

Excessive influx and the subsequent rapid cytosolic elevation of Ca2+ in neurons is the major cause to induce hyperexcitability and irreversible cell damage although it is an essential ion for cellular signalings. Therefore, most neurons exhibit several cellular mechanisms to homeostatically regulate cytosolic Ca2+ level in normal as well as pathological conditions. Delayed rectifier K+ channels (IDR channels) play a role to suppress membrane excitability by inducing K+ outflow in various conditions, indicating their potential role in preventing pathogenic conditions and cell damage under Ca2+-mediated excitotoxic conditions. In the present study, we electrophysiologically evaluated the response of IDR channels to hyperexcitable conditions induced by high Ca2+ pretreatment (3.6 mM, for 24 hours) in cultured hippocampal neurons. In results, high Ca2+-treatment significantly increased the amplitude of IDR without changes of gating kinetics. Nimodipine but not APV blocked Ca2+-induced IDR enhancement, confirming that the change of IDR might be targeted by Ca2+ influx through voltage-dependent Ca2+ channels (VDCCs) rather than NMDA receptors (NMDARs). The VDCC-mediated IDR enhancement was not affected by either Ca2+-induced Ca2+ release (CICR) or small conductance Ca2+-activated K+ channels (SK channels). Furthermore, PP2 but not H89 completely abolished IDR enhancement under high Ca2+ condition, indicating that the activation of Src family tyrosine kinases (SFKs) is required for Ca2+-mediated IDR enhancement. Thus, SFKs may be sensitive to excessive Ca2+ influx through VDCCs and enhance IDR to activate a neuroprotective mechanism against Ca2+-mediated hyperexcitability in neurons.

8.
Nano Lett ; 16(7): 4322-8, 2016 07 13.
Article in English | MEDLINE | ID: mdl-27332701

ABSTRACT

The smallness of natural molecules and atoms with respect to the wavelength of light imposes severe limits on the nature of their optical response. For example, the well-known argument of Landau and Lifshitz and its recent extensions that include chiral molecules show that the electric dipole response dominates over the magneto-electric (bianisotropic) and an even smaller magnetic dipole optical response for all natural materials. Here, we experimentally demonstrate that both these responses can be greatly enhanced in plasmonic nanoclusters. Using atomic force microscopy nanomanipulation technique, we assemble a plasmonic metamolecule that is designed for strong and simultaneous optical magnetic and magneto-electric excitation. Angle-dependent scattering spectroscopy is used to disentangle the two responses and to demonstrate that their constructive/destructive interplay causes strong directional scattering asymmetry. This asymmetry is used to extract both magneto-electric and magnetic dipole responses and to demonstrate their enhancement in comparison to ordinary atomistic materials.

9.
Environ Geochem Health ; 38(5): 1137-1146, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26493832

ABSTRACT

Pyrite and other iron sulfides are readily oxidized by dissolved oxygen in aqueous phase, producing acidity and Fe(2+), which causes significant environmental problems. Applications of surface coating agents (Na2SiO3 and KH2PO4) were conducted at Boeun (Chungbuk, South Korea) outcrop site, and their efficiencies to inhibit the oxidation of sulfide minerals were monitored for a long-term period (449 days). The rock sample showed positive Net Acid Production Potential (NAPP = 20.23) and low Net Acid Generation pH (NAGpH = 2.42) values, suggesting that the rock sample was categorized in the potential acid-forming group. For the monitored time period (449 days), field study results showed that the application of Na2SiO3 effectively inhibited the pyrite oxidation as compared to KH2PO4. Na2SiO3 as a surface coating agent maintained pH 5-6 and reduced oxidation of pyrite surface up to 99.95 and 97.70 % indicated by Fe(2+) and SO4 (2-) release, respectively. The scanning electron microscope and energy-dispersive X-ray spectrometer analysis indicated that the morphology of rock surface was completely changed attributable to formation of iron silicate coating. The experimental results suggested that the treatment with Na2SiO3 was highly effective and it might be applicable on field for inhibition of iron sulfide oxidation.


Subject(s)
Environmental Restoration and Remediation/methods , Iron/chemistry , Oxidation-Reduction , Sulfides/chemistry , Microscopy, Electron, Scanning , Phosphates/chemistry , Potassium Compounds/chemistry , Republic of Korea , Silicates/chemistry , Spectrometry, X-Ray Emission
10.
Adv Mater ; 27(41): 6397-403, 2015 Nov 04.
Article in English | MEDLINE | ID: mdl-26372164

ABSTRACT

Laser induced selective photothermochemical reduction is demonstrated to locally and reversibly control the oxidation state of Cu and Cu oxide nanowires in ambient conditions without any inert gas environment. This new concept of "nanorecycling" can monolithically integrate Cu and Cu oxide nanowires by restoring oxidized Cu, considered unusable for the electrode, back to a metallic state for repetitive reuse.


Subject(s)
Copper/chemistry , Nanowires/chemistry , Electrodes , Lasers , Oxidation-Reduction , Spectrometry, X-Ray Emission
11.
Phys Chem Chem Phys ; 17(32): 20786-94, 2015 Aug 28.
Article in English | MEDLINE | ID: mdl-26214275

ABSTRACT

The theoretical extinction coefficients of gold nanoparticles (AuNPs) have been mainly verified by the analytical solving of the Maxwell equation for an ideal sphere, which was firstly founded by Mie (generally referred to as Mie theory). However, in principle, it has not been directly feasible with experimental verification especially for relatively large AuNPs (i.e., >40 nm), as conventionally proposed synthetic methods have inevitably resulted in a polygonal shaped, non-ideal Au nanosphere. Here, mono-crystalline, ultra-smooth, and highly spherical AuNPs of 40-100 nm were prepared by the procedure reported in our recent work (ACS Nano, 2013, 7, 11064). The extinction coefficients of the ideally spherical AuNPs of 40-100 nm were empirically extracted using the Beer-Lambert law, and were then compared with the theoretical limits obtained by the analytical and numerical methods. The obtained extinction coefficients of the ideally spherical AuNPs herein agree much more closely with the theoretical limits, compared with those of the faceted or polygonal shaped AuNPs. In addition, in order to further elucidate the importance of being spherical, we systematically compared our ideally spherical AuNPs with the polygonal counterparts; effectively addressing the role of the surface morphology on the spectral responses in both theoretical and experimental manners.

12.
J Nanosci Nanotechnol ; 15(10): 7922-8, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26726441

ABSTRACT

Indole-3-carbinol (I3C) has anti-oxidant and anti-inflammatory properties. Nonetheless, the potential of I3C to treat neurodegenerative diseases remains unclear because of its poor ability to penetrate the blood-brain barrier (BBB). Because polymer-based drug delivery systems stabilized by surfactants have been intensively utilized as a strategy to cross the blood-brain barrier, we prepared I3C-loaded poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) that were stabilized by Tween 80 (T80) (I3C-PLGA-T80-NPs) and examined their neuroprotective potential in vitro. We prepared I3C-PLGA-T80-NPs with an oil-in-water (o/w) emulsion solvent evaporation technique and confirmed their successful synthesis with both transmission electron microscopy and Fourier transform-infrared spectroscopy. I3C-PLGA-T80-NPs were then used to treat PC12 neuronal cells injured by glutamate excitotoxicity (GE) and examined the resulting survival rates compared with PC12 cells treated with I3C only. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay revealed higher survival rates in I3C-PLGA-T80-NPs-treated cells after GE injury compared with those treated with I3C only. Furthermore, I3C-PLGA-T80-NPs decreased the levels of reactive oxygen species (ROS) and apoptosis-related enzymes (Caspase-3 and -8) in GE-damaged neuronal cells. Taken together, I3C-PLGA-T80-NPs might possess neuroprotective effects against GE through ROS scavenging and subsequent apoptosis blockage.


Subject(s)
Antimicrobial Cationic Peptides , Apoptosis/drug effects , Indoles , Nanoparticles/chemistry , Neuroprotective Agents , Neurotoxicity Syndromes/prevention & control , Animals , Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/pharmacology , Indoles/chemistry , Indoles/pharmacology , Neuroprotective Agents/chemistry , Neuroprotective Agents/pharmacology , Neurotoxicity Syndromes/metabolism , Neurotoxicity Syndromes/pathology , PC12 Cells , Rats
13.
EMBO J ; 31(22): 4289-303, 2012 Nov 14.
Article in English | MEDLINE | ID: mdl-23085987

ABSTRACT

Premature senescence, a key strategy used to suppress carcinogenesis, can be driven by p53/p21 proteins in response to various stresses. Here, we demonstrate that Wig1 plays a critical role in this process through regulation of p21 mRNA stability. Wig1 controls the association of Argonaute2 (Ago2), a central component of the RNA-induced silencing complex (RISC), with target p21 mRNA via binding of the stem-loop structure near the microRNA (miRNA) target site. Depletion of Wig1 prohibited miRNA-mediated p21 mRNA decay and resulted in premature senescence. Wig1 plays an essential role in cell proliferation, as demonstrated in tumour xenografts in mice, and Wig1 and p21 mRNA levels are inversely correlated in human normal and cancer tissues. Together, our data indicate a novel role of Wig1 in RISC target accessibility, which is a key step in RNA-mediated gene silencing. In addition, these findings indicate that fine-tuning of p21 levels by Wig1 is essential for the prevention of cellular senescence.


Subject(s)
Carrier Proteins/metabolism , Cellular Senescence , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Nuclear Proteins/metabolism , RNA Stability/physiology , RNA-Induced Silencing Complex/metabolism , Animals , Argonaute Proteins/metabolism , Cell Line, Tumor , Humans , Lung Neoplasms/metabolism , Mice , Neoplasm Transplantation , RNA-Binding Proteins
14.
Plant Foods Hum Nutr ; 67(1): 71-5, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22350499

ABSTRACT

The aim of this investigation was to evaluate the biological, alcohol dehydrogenase (ADH) and antiproliferative activities of different extracts of mungbean seeds and sprouts. All extracts from the sprouts showed higher contents of total phenolics (TP), total flavonoids (TF), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than from seeds. The highest DPPH and tyrosinase inhibition activities were registered in ethyl acetate (EtOAc) extract. ADH activity of methanol (MeOH), n-hexane (n-hexane) and n-butanol (n-BuOH) extracts from sprouts was significantly higher (P < 0.05) than from seeds. However, the highest ADH activity was found in water extract of seeds. According to 3-(4, 5-dimethylthiazol -2-yl)-2, 5-diphenyltetrazolium bromide) (MTT) assay, extracts from sprouts were more effective against Calu-6 (human pulmonary carcinoma) and SNU-601 (human gastric carcinoma) cells than from seeds. EtOAc extract showed the highest antiproliferative activity in both sprouts and seeds, followed by n-hexane extraction. During sprouting of mungbean, all the studied components significantly increased. In conclusion, the extracts of sprouts are more effective than from seeds and could be a potential source of antioxidants linked with health benefits.


Subject(s)
Fabaceae/chemistry , Plant Extracts/pharmacology , Seedlings/chemistry , Seeds/chemistry , Alcohol Dehydrogenase/metabolism , Antineoplastic Agents, Phytogenic/analysis , Antineoplastic Agents, Phytogenic/pharmacology , Antioxidants/analysis , Antioxidants/pharmacology , Cell Line, Tumor , Fabaceae/enzymology , Flavonoids/analysis , Flavonoids/pharmacology , Free Radical Scavengers/analysis , Free Radical Scavengers/pharmacology , Humans , Inhibitory Concentration 50 , Monophenol Monooxygenase/antagonists & inhibitors , Phenols/analysis , Phenols/pharmacology , Plant Extracts/chemistry , Seedlings/enzymology , Seeds/enzymology
15.
Plant Foods Hum Nutr ; 64(1): 25-31, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19016328

ABSTRACT

UNLABELLED: The aim of this investigation was to study the antioxidant and anticancer activities of young sprouts of some traditional Korean salad plants. Total phenolics, antioxidant and anticancer activities of the methanol extracts from young sprouts of 11 salad plants were determined. The highest amount of phenolics was found in methanol extracts of Euonymus alatus (235.7 mg kg(-1)), followed by Hypericum ascyron (197.1 mg kg(-1)), Zanthoxylum piperitum (194.1 mg kg(-1)) and Zanthoxylum schinifolium (142.5 mg kg(-1)). Methanol extracts of E. alatus, H. ascyron, and Z. piperitum at 63 mg kg(-1) exhibited the highest dose-depend DPPH radical scavenging activity by 91.2, 91.2 and 83.9%, respectively. According to the MTT results, the methanol extracts from Stellaria aquatica, Eleutherococcus sessilifolrus and Z. schinifolium showed the highest anticancer activities against Calu-6 (IC50<25.0 microg ml(-1)) and from S. aquatica-the highest anticancer activities against SNU-601 (153.3 microg ml(-1)), following by E. sessilifolrus (196.7 microg ml(-1)) and Amaranthus mangostanus (303.1 microg ml(-1)). Total phenolics were highly correlated with the DPPH, suggesting that they contribute to the antioxidant properties of the studied plants. IN CONCLUSION: young sprouts of Korean salad possess antioxidant and anticancer properties and could be used as a supplement to proper drugs.


Subject(s)
Antineoplastic Agents, Phytogenic/analysis , Antioxidants/analysis , Phenols/analysis , Plant Extracts/analysis , Antineoplastic Agents, Phytogenic/pharmacology , Antioxidants/metabolism , Antioxidants/pharmacology , Eleutherococcus/chemistry , Euonymus/chemistry , Free Radical Scavengers , Hypericum/chemistry , Korea , Phenols/pharmacology , Plant Extracts/pharmacology , Species Specificity , Stellaria/chemistry , Zanthoxylum/chemistry
16.
J Polym Sci A Polym Chem ; 47(5): 1429-1439, 2009 Mar 01.
Article in English | MEDLINE | ID: mdl-20161099

ABSTRACT

We investigated the formation of ground state donor/acceptor complexes between xanthene dyes (rose Bengal (RB) and fluorescein (FL)) and a diphenyl iodonium salt (DPI) which is dissolved in 2-hydroxyethyl methacrylate (HEMA) monomer. To characterize the association constant of the complex, we have suggested a new analysis model based upon the Benesi-Hildebrand model. Because the assumption of the original Benesi-Hildebrand model is that the absorption bands are due only to the presence of the complex and that the absorption by the free component is negligible; the model cannot be applied to our systems, which is a dye-based initiator system. For each dye, the molar absorptivity of the ground state complex was evaluated as a function of wavelength and this analysis confirmed the validity of the modified Benesi-Hildebrand model. In addition, we observed the RB/DPI photoinitiator system failed to produce a perceptible polymerization rate but the FL/DPI photoinitiator system provided very high rates of polymerization. Based upon the association constant for these complexes, we concluded that the observed kinetic differences arise from the different association constant values of the ground state dye-acceptor complex, resulting in back electron transfer reaction.

17.
Acta Oncol ; 42(3): 207-17, 2003.
Article in English | MEDLINE | ID: mdl-12852697

ABSTRACT

A prospective phase II study of neoadjuvant chemoradiotherapy (CRT) for resectable esophageal squamous cell carcinoma was conducted from May 1993 to March 1996. A total of 88 patients fitted the eligibility criteria and were treated with two courses of induction chemotherapy (cisplatin 60 mg/m2/day on day 1 and 5-fluorouracil (5-FU) 1000 mg/m2/day on days 2-6) with concurrent hyperfractionated radiotherapy (48 Gy/40 fractions/4 weeks) followed by esophagectomy or definitive CRT comprising 4 cycles of cisplatin/5-FU and hyperfractionated radiotherapy (additional 12 Gy) with intracavitary brachytherapy (9 Gy). Clinical response and downstaging were achieved in 83% and 42% of the patients, respectively. With a median follow-up of 77 months, median survival time was 18 months with a 5-year survival rate of 23%. The clinical responses to CRT and surgery were independent prognostic factors for overall survival. Among the intended surgery group (n = 52), 41 (79%) patients underwent surgery and 36 had a resection with a pathologic complete response rate of 43%. When compared with a matched historical control (n = 40), there was a significant survival benefit in the multimodality arm (p = 0.04). This multimodality therapy was feasible and its efficacy was promising, especially when surgical resection was performed. The therapeutic benefit of neoadjuvant CRT remains to be assessed in large well-designed randomized trials, one of which is ongoing at our institution.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Squamous Cell/drug therapy , Esophageal Neoplasms/drug therapy , Neoadjuvant Therapy , Adult , Aged , Aged, 80 and over , Carcinoma, Squamous Cell/radiotherapy , Carcinoma, Squamous Cell/surgery , Cisplatin/administration & dosage , Combined Modality Therapy , Esophageal Neoplasms/radiotherapy , Esophageal Neoplasms/surgery , Esophagectomy , Female , Fluorouracil/administration & dosage , Humans , Male , Middle Aged , Prognosis , Survival
18.
Chest ; 121(1): 210-5, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11796453

ABSTRACT

STUDY OBJECTIVES: The diaphragm adapts to its shortened state in experimental emphysema primarily by losing sarcomeres in series, thus reducing its optimal operating length. One would expect improved diaphragmatic function after lung volume reduction surgery (LVRS) only if the muscle can readapt to its elevated, lengthened postoperative position by either adding back sarcomeres or lengthening sarcomeres. We used a model of elastase-induced emphysema in rats to test the hypothesis that sarcomere addition occurs following LVRS. DESIGN: A cohort of emphysematous rats was created by the intratracheal instillation of elastase. Five months after the instillation, one group of rats underwent measurement of in situ costal diaphragm length via laparotomy, the determination of optimal muscle fiber operating length (Lo) on stimulated diaphragm strips in vitro, and the measurement of sarcomere length by electron microscopy on strips fixed at Lo. Another group of rats underwent LVRS or sham sternotomy 5 months after the instillation, and 5 months following the operation these animals underwent the same series of diaphragmatic studies. RESULTS: Lo was significantly greater in rats that underwent LVRS than those that underwent sternotomy (mean [+/- SE] Lo after LVRS, 2.50 +/- 0.08 cm; mean Lo after sternotomy, 2.27 +/- 0.06 cm; p = 0.013). There was no significant difference in sarcomere lengths between the two groups (2.95 +/- 0.04 vs 3.04 +/- 0.04 microm, respectively; p = 0.10). Using Lo as the length basis, the mean sarcomere number was calculated to be 8,712 +/- 192 in animals that had undergone LVRS and 7,144 +/- 249 in animals that had undergone sternotomy (p < 0.001). CONCLUSION: Sarcomere length is not significantly altered but sarcomeres are added in series following LVRS in this experimental model of emphysema/LVRS. It is likely that this sarcomere addition is a prerequisite to the improvement in inspiratory muscle function that has been observed following LVRS in humans.


Subject(s)
Diaphragm/pathology , Pneumonectomy , Postoperative Complications/pathology , Pulmonary Emphysema/surgery , Sarcomeres/pathology , Animals , Lung/pathology , Microscopy, Electron , Pancreatic Elastase , Pulmonary Emphysema/chemically induced , Pulmonary Emphysema/pathology , Rats , Rats, Sprague-Dawley
SELECTION OF CITATIONS
SEARCH DETAIL
...